WorldWideScience

Sample records for urban shellfishing subestuary

  1. Shellfish Allergy

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Shellfish Allergy KidsHealth / For Parents / Shellfish Allergy What's in this ... Print en español Alergia al marisco About Shellfish Allergy A shellfish allergy is not exactly the same ...

  2. Shellfish Allergy

    Science.gov (United States)

    ... of reactions. Learn more here. Milk Egg Peanut Tree Nuts Soy Wheat Fish Shellfish Sesame Other Food ... federal law. Download this resource about how to identify shellfish on food labels. Avoid foods that contain ...

  3. Role of Shellfish Aquaculture in the Reduction of Eutrophication in an Urban Estuary

    Science.gov (United States)

    Land-based management has reduced nutrient discharges; however, many coastal waterbodies remain impaired. Oyster “bioextraction” of nutrients and how oyster aquaculture might complement existing management measures in urban estuaries was examined in Long Island Sound, Connecticut...

  4. The role of shellfish aquaculture in reduction of eutrophication in an urban estuary

    DEFF Research Database (Denmark)

    Bricker, Suzanne B.; Ferreira, Joao Gomes; Zhu, Changbo

    2018-01-01

    from the system-scale modeling, suggesting that this upscaling method could be useful in waterbodies without circulation models. The minimum value of the ecosystem service of nitrogen removed by oyster production was estimated by means of an avoided costs method, which uses the cost of alternative......, as an example of how aquaculture might complement land-based measures in urban estuaries. Eutrophication status, nutrient removal, and ecosystem service value were estimated through eutrophication assessment, application of hydrologic, circulation, and local- and ecosystem-scale models, and economic valuation....... System-scale modeling estimated that current oyster aquaculture, via sequestration into tissue and shell only, removes an equivalent of 1.31%, and expanded production could remove 2.68%, of total annual land-based nitrogen inputs by aquaculture alone. Up-scaled local-scale results were similar to results...

  5. Shellfish Harvest Prohibition Areas for 2011; shellfish11

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — Geospatial vector polygon data defining shellfishing prohibition areas, seasonal, and conditional shellfish closure areas, and areas open to legal shellfish...

  6. Amnesic Shellfish Poisoning (ASP)

    DEFF Research Database (Denmark)

    Ravn, H.

    HAB Publ. Ser. vol 1 is a supplement to Chapter 7 Mehtods for Domoic Acid, the Amnesic Shellfish Poisons in the IOC Manual of Harmful Marine Microalgae......HAB Publ. Ser. vol 1 is a supplement to Chapter 7 Mehtods for Domoic Acid, the Amnesic Shellfish Poisons in the IOC Manual of Harmful Marine Microalgae...

  7. Poisoning - fish and shellfish

    Science.gov (United States)

    Fish poisoning; Dinoflagellate poisoning; Seafood contamination; Paralytic shellfish poisoning; Ciguatera poisoning ... algae and algae-like organisms called dinoflagellates. Small fish that eat the algae become contaminated. If larger ...

  8. Fish and shellfish allergy.

    Science.gov (United States)

    Thalayasingam, Meera; Lee, Bee-Wah

    2015-01-01

    Fish and shellfish consumption has increased worldwide, and there are increasing reports of adverse reactions to fish and shellfish, with an approximate prevalence of 0.5-5%. Fish allergy often develops early in life, whilst shellfish allergy tends to develop later, from adolescence onwards. Little is known about the natural history of these allergies, but both are thought to be persistent. The clinical manifestations of shellfish allergy, in particular, may vary from local to life-threatening 'anaphylactic' reactions within an individual and between individuals. Parvalbumin and tropomyosin are the two major allergens, but several other allergens have been cloned and described. These allergens are highly heat and biochemically stable, and this may in part explain the persistence of these allergies. Diagnosis requires a thorough history, skin prick and in-vitro-specific IgE tests, and oral challenges may be needed for diagnostic confirmation. Strict avoidance of these allergens is the current standard of clinical care for allergic patients, and when indicated, an anaphylactic plan with an adrenaline auto-injector is prescribed. There are no published clinical trials evaluating specific oral immunotherapy for fish or shellfish allergy. © 2015 S. Karger AG, Basel.

  9. Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise.

    Science.gov (United States)

    Beckett, Leah H; Baldwin, Andrew H; Kearney, Michael S

    2016-01-01

    Sea-level rise is a major factor in wetland loss worldwide, and in much of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mm yr-1 due to regional subsidence. Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, and may exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In one of the first studies to examine elevation dynamics across an estuarine salinity gradient, we installed 15 surface elevation tables (SET) and accretion marker-horizon plots (MH) in tidal freshwater, oligohaline, and brackish marshes across a Chesapeake Bay subestuary. Over the course of four years, wetlands across the subestuary decreased 1.8 ± 2.7 mm yr-1 in elevation on average, at least 5 mm yr-1 below that needed to keep pace with global sea-level rise. Elevation change rates did not significantly differ among the marshes studied, and ranged from -9.8 ± 6.9 to 4.5 ± 4.3 mm yr-1. Surface accretion of deposited mineral and organic matter was uniformly high across the estuary (~9-15 mm yr-1), indicating that elevation loss was not due to lack of accretionary input. Position in the estuary and associated salinity regime were not related to elevation change or surface matter accretion. Previous studies have focused on surface elevation change in marshes of uniform salinity (e.g., salt marshes); however, our findings highlight the need for elevation studies in marshes of all salinity regimes and different geomorphic positions, and warn that brackish, oligohaline, and freshwater tidal wetlands may be at similarly high risk of submergence in some estuaries.

  10. Antimicrobial Susceptibility among Urban Wastewater and Wild Shellfish Isolates of Non-O1/Non-O139 Vibrio cholerae from La Rance Estuary (Brittany, France

    Directory of Open Access Journals (Sweden)

    Sandrine Baron

    2017-09-01

    Full Text Available The early 2000s marked the end of the Golden age of the antibiotics and the beginning of the awareness on the potential threat to human health due to the dissemination of antimicrobial resistance. As a base-line study, we investigated the antimicrobial susceptibility of 99 strains of non-O1/non-O139 Vibrio cholerae isolated from wastewater and shellfish in 2000/2001 within La Rance estuary (Brittany, France. All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, nalidixic acid, ciprofloxacin, norfloxacin, amikacin, gentamicin, tetracycline, doxycycline, trimethoprim-sulfamethoxazole, and erythromycin. The only resistances were to streptomycin, sulfonamides and ampicillin: 54.6% of the isolates had acquired resistance to at least one antimicrobial agent among them and only six isolates from cockles were multidrug resistant. On the basis of the distribution of a limited selection of resistance associated genes, our study shows that V. cholerae can constitute an environmental reservoir for these genes. However, none of our isolates harbored integron. This result casts doubt on the capacity of non-O1/non-O139 V. cholerae to acquire resistance-associated genes in such context, and on its potential role of indicator of the dissemination of antimicrobial resistance in the aquatic environment.

  11. Drivers of phytoplankton dynamics in old Tampa Bay, FL (USA), a subestuary lagging in ecosystem recovery

    Science.gov (United States)

    Corcoran, Alina A.; Wolny, Jennifer; Leone, Erin; Ivey, James; Murasko, Susan

    2017-02-01

    In the past four decades, consistent and coordinated management actions led to the recovery of Tampa Bay, FL (USA) - an estuary that was declared dead in the 1970s. An exception to this success story is Old Tampa Bay, the northernmost subestuary of the system. Compared to the other bay segments, Old Tampa Bay is characterized by poorer water quality and spring and summer blooms of cyanobacteria, picoplankton, diatoms, and the saxitoxin-producing dinoflagellate Pyrodinium bahamense. Together, these blooms contribute to light attenuation and lagging recovery of seagrass beds. Yet, studies of phytoplankton dynamics within Old Tampa Bay have been limited - both in number and in their spatiotemporal resolution. In this study, we used field sampling and continuous monitoring to (1) characterize temporal and spatial variability in phytoplankton biomass and community composition and (2) identify key drivers of the different phytoplankton blooms in Old Tampa Bay. Overall, temporal variability in phytoplankton biomass (using chlorophyll a as a proxy) and community composition surpassed spatial variability of these parameters. We found a base community of small diatoms and flagellates, as well as certain dinoflagellates, that persisted year round in the system. Seasonally, freshwater runoff stimulated phytoplankton growth, specifically that of chlorophytes, cyanobacteria and other dinoflagellates - consistent with predictions based on ecological theory. On shorter time scales, salinity, visibility, and freshwater inflows were important predictors of phytoplankton biomass. With respect to P. bahamense, environmental drivers including salinity, temperature and dissolved nutrient concentrations explained ∼24% of the variability in cell abundance, indicating missing explanatory parameters in our study for this taxon, such as cyst density and location of cyst beds. Spatially, we found differences in community trajectories across north-south and west-east gradients, with the

  12. Neurotoxic shellfish poisoning: A review

    NARCIS (Netherlands)

    Apeldoorn ME van; Egmond HP van; Speijers GJA; CSR; ARO

    2001-01-01

    This review contains information on the neurotoxic shellfish poisoning (NSP) syndrome and the provoking toxins called brevetoxins, produced by the dinoflagellate Gymnodinium breve. Data on chemical structures and detection methods for brevetoxins, sources for brevetoxins, marine organisms associated

  13. Neurotoxic shellfish poisoning: A review

    NARCIS (Netherlands)

    Apeldoorn ME van; Egmond HP van; Speijers GJA; CSR; ARO

    2001-01-01

    Dit literatuuroverzicht bevat informatie betreffende het "neurotoxic shellfish poisoning" (NSP) syndroom en de veroorzakende toxines, nl.de brevetoxines, welke geproduceerd worden door de dinoflagellaat Gymnodinium breve. Chemische structuren en detectie-methodes van de brevetoxines,

  14. Shellfish Hemocyte Data from Flow Cytometers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various immune function tests using shellfish hemolymph have been developed to determine shellfish health. These tests including viability, phagocytosis, adhesion,...

  15. Risk Assessment of Shellfish Toxins

    Directory of Open Access Journals (Sweden)

    Rex Munday

    2013-11-01

    Full Text Available Complex secondary metabolites, some of which are highly toxic to mammals, are produced by many marine organisms. Some of these organisms are important food sources for marine animals and, when ingested, the toxins that they produce may be absorbed and stored in the tissues of the predators, which then become toxic to animals higher up the food chain. This is a particular problem with shellfish, and many cases of poisoning are reported in shellfish consumers each year. At present, there is no practicable means of preventing uptake of the toxins by shellfish or of removing them after harvesting. Assessment of the risk posed by such toxins is therefore required in order to determine levels that are unlikely to cause adverse effects in humans and to permit the establishment of regulatory limits in shellfish for human consumption. In the present review, the basic principles of risk assessment are described, and the progress made toward robust risk assessment of seafood toxins is discussed. While good progress has been made, it is clear that further toxicological studies are required before this goal is fully achieved.

  16. Fish and Shellfish Associated Disease Outbreaks.

    Science.gov (United States)

    Levin, M.

    1978-01-01

    Presents a literature review of disease outbreaks related to fish and shellfish, covering publications of 1976-77. This review covers the chemical, bacterial, and viral diseases that are transmitted by fish and shellfish. A list of 50 references is also presented. (HM)

  17. Shellfish as reservoirs of bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Harry Hariharan

    2016-04-01

    Full Text Available The objective of this article is to present an overview on bacterial pathogens associated with shellfish in Grenada and other countries including the authors’ experience. Although there have been considerable published work on vibrios, there is a lack of information on Salmonella serovars associated with various shellfish. In Grenada, for instance the blue land crabs collected from their habitats were found to harbor several Salmonella serovars. Also, it is notable that only minimal research has been done on shellfish such as conchs and whelks, which are common in the Caribbean and West Indies. Information on anaerobic bacteria, particularly, non-spore forming bacteria associated with shellfish, in general, is also scanty. This review re-examines this globally important topic based on the recent findings as well as past observations. Strategies for reduction of bacteria in oysters are briefly mentioned because of the fact that oysters are consumed commonly without complete cooking.

  18. [Nutritive value of shellfish consumed in Chile].

    Science.gov (United States)

    Pak, N; Vera, G; Araya, H

    1985-03-01

    The purpose of the present study was to determine the protein quality and digestibility of shellfish commonly consumed in Chile, and to estimate its contribution to the protein needs of the Chilean population. The shellfish studied were chorito (Mytilus edulis chilensis), macha (Mesodesma donacium), loco (Concholepas concholepas), cholga (Aulacomya ater), erizo (Loxechinus albus) and almeja (no specific variety). The NPU method was used to determine protein quality. The percentage of protein adequacy for adult rations was calculated according to FAO/WHO 1973. The contribution of shellfish to the protein availability according to the family income of the Santiago population, was also calculated. Most of the shellfish presented NPU values of about 70; the lowest values were found for loco (54.9) and macha (63.3). The apparent and true digestibility gave an average of 83.6 and 90.4, respectively. The percentage of protein adequacy of habitual rations ranged between 27% (erizo) and 58% (loco). The availability of shellfish protein in relation to total protein increased from 0.4 to 2.5% when income increased. It is concluded therefore, that shellfish protein is, in general, of good quality. Nevertheless, it might be considered of poor influence insofar as fulfilling the protein needs of the population studied, whatever its socioeconomic level.

  19. Upriver transport of dissolved substances in an estuary and sub-estuary system of the lower James River, Chesapeake Bay

    Science.gov (United States)

    Hong, Bo; Shen, Jian; Xu, Hongzhou

    2018-01-01

    The water exchange between the James River and the Elizabeth River, an estuary and sub-estuary system in the lower Chesapeake Bay, was investigated using a 3D numerical model. The conservative passive tracers were used to represent the dissolved substances (DS) discharged from the Elizabeth River. The approach enabled us to diagnose the underlying physical processes that control the expansion of the DS, which is representative of potential transport of harmful algae blooms, pollutants from the Elizabeth River to the James River without explicitly simulating biological processes. Model simulations with realistic forcings in 2005, together with a series of processoriented numerical experiments, were conducted to explore the correlations of the transport process and external forcing. Model results show that the upriver transport depends highly on the freshwater discharge on a seasonal scale and maximum upriver transport occurs in summer with a mean transport time ranging from 15-30 days. The southerly/easterly wind, low river discharge, and neap tidal condition all act to strengthen the upriver transport. On the other hand, the northerly/westerly wind, river pulse, water level pulse, and spring tidal condition act to inhibit the upriver transport. Tidal flushing plays an important role in transporting the DS during spring tide, which shortens the travel time in the lower James River. The multivariable regression analysis of volume mean subtidal DS concentration in the mesohaline portion of the James River indicates that DS concentration in the upriver area can be explained and well predicted by the physical forcings (r = 0.858, p = 0.00001).

  20. Irradiation preservation of Korean shellfish

    International Nuclear Information System (INIS)

    Chung, J.R.; Kim, S.I.; Lee, M.C.

    1976-01-01

    Pacific oyster, hard clam and mussel were irradiated at doses up to 0.5 Mrad, the optimum dose rather than the maximum permissible was sought for in each species and post-irradiation storage characteristics studied at 0 0 and 5 0 C. No shellfish meat irradiated at doses as high as 0.5 Mrad produced any adverse odor. However the organoleptic quality of each sample irradiated at lower doses was superior to those irradiated at the higher during the early storage period. The optimum dose was determined to be 0.2 Mrad for Pacific oyster and mussel and 0.1 Mrad for hard clam. By irradiating at the optimum dose, the storage life of Pacific oyster could be extended from less than 14 days to 35 days at 0 0 C and from only 3 days to 21 days at 5 0 C. A similar storage extension was observed from 7 days to 14 days at 0 0 C and from 3 days to 12 days at 5 0 C. The hard clam meats were particularly susceptible to tissue softening by irradiation; an earlier onset and more extensive softening were observed with increasing dose. (author)

  1. Shellfish Feeding Experiments, Filter Weight and Tissue Weight

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Particulate matter removal by shellfish was quantified in several geographic locations, across several years. Data include filter and shellfish tissue weights.

  2. [Epidemiology of toxic and infectious risk related to shellfish consumption].

    Science.gov (United States)

    Desenclos, J C

    1996-10-01

    For feeding purposes shellfish filter large amounts of water but also concentrate infectious agents and toxins that are present in the marine environment either naturally or because of pollution. Thus, the consumption of raw or undercooked shellfish is a substantial source of foodborne poisoning, mostly epidemic and sometimes sporadic. Most of shellfish-borne infectious diseases are linked to fecal contamination of the marine environment; they include: thyphoid fever, salmonellosis, shigellosis, campylobacteriosis, cholera, Norwalk or Norwalk-like gastroenteritis and hepatitis A. In warm climates, shellfish contains naturally occurring halopilic Vibrios and may cause severe sporadic infections (septicemias) among very susceptible consumers (immunocompromised). Shellfish also causes outbreaks of paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP) when they are contaminated by toxins produced when Dinophisis, a marine plancton, proliferates. Chemical compounds (heavy metals and organic toxins) that are dumped in the environment (soil, air, and water) also reach shellfish harvesting waters where they are cocentrated. Although acute or chronic effects of the chemical contamination of shellfish have not been clearly documented, the cadmium pollution of some shellfish harvesting waters raises a serious problem. Since it is impossible to prevent completely the contamination of coastal waters by any of the agents cited above, the prevention of shellfish-borne diseases requires monitoring of the marine environment and shellfish flesh (coliform count, Dinophysis toxins, heavy metals...). This surveillance allows the classification of growing areas as suitable or not for harvesting and distribution of shellfish. However, this surveillance is not always sensitive enough. Indicators of fecal pollution are particularly not reliable for shellfish viral contamination. A better knowledge of marine biology, the limitation of coastal waters pollution, improved

  3. Shellfish reef restoration pilots: Voordelta The Netherlands

    NARCIS (Netherlands)

    Sas, H.; Kamermans, P.; Have, van der T.M.; Lengkeek, W.; Smaal, A.C.

    2016-01-01

    Once, shellfish reefs - mainly flat oysters - covered about 20% of the North Sea floor, but diseases, pollution and overfishing have led to a significant decline. As part of the Haringvliet Dream Fund Project (www.haringvliet.nu), ARK
    Nature and World Wildlife Fund Netherlands are working on

  4. 76 FR 65200 - Risk Assessment on Norovirus in Bivalve Molluscan Shellfish: Request for Comments and for...

    Science.gov (United States)

    2011-10-20

    ... transmission of norovirus from infected or ill food workers in food manufacturing or retail establishments to... Molluscan Shellfish Contamination Levels During Food Preparation and Bivalve Molluscan Shellfish Consumption... and other factors influencing bivalve molluscan shellfish contamination levels during food preparation...

  5. Detection of salmonella in shellfish grown in polluted seawater

    CSIR Research Space (South Africa)

    Kfir, R

    1993-01-01

    Full Text Available Three bays along the South African coast were studied for the presence of Salmonella spp in seawater, effluent and storm water discharges into the bays and in shellfish harvested at the same sites. The microbial quality of water and shellfish...

  6. Accumulation of diarrhetic shellfish poisoning toxins in the oyster ...

    African Journals Online (AJOL)

    Diarrhetic shellfish poisoning (DSP) poses a significant threat to the safe consumption of shellfish in the southern Benguela ecosystem. The accumulation of DSP toxins was investigated in two cultivated bivalve species, the Pacific oyster Crassostrea gigas and the mussel Choromytilus meridionalis, suspended from a ...

  7. Radioimmunoassay of paralytic shellfish toxins in clams and mussels

    International Nuclear Information System (INIS)

    Yang, G.C.; Imagire, S.J.; Yasaei, P.; Ragelis, E.P.; Park, D.L.; Page, S.W.; Carlson, R.E.; Guire, P.E.

    1987-01-01

    Shellfish contaminated with paralytic shellfish poisons (PSP) compromise human health. The threat of this contamination results in enormous economic losses in the recreational and commercial exploitation of shellfish resources in the affected areas. Most states deal with the PSP problem either by prohibiting the collection of shellfish during certain time periods or by instituting monitoring programs. The only recognized method of analysis for PSP that is currently and routinely used in monitoring programs is the time-of-death mouse bioassay. Several attempts to develop simple and highly specific biochemical assays for the detection and quantitation of the PSP toxins have been reported. More recently, much improved immunoassays have been developed. To evaluate the validity and usefulness of the immunoassay for the determination of PSP toxins, the authors have used extracts of shellfish gathered from Maine and Connecticut to compare the results of the mouse bioassay and HPLC methods with the radioimmunoassay developed previously

  8. 50 CFR 100.28 - Subsistence taking of shellfish.

    Science.gov (United States)

    2010-10-01

    ... eggs, unless otherwise specified. (4) You may not use explosives and chemicals, except that you may use...) Cook Inlet Area. (i) You may take shellfish for subsistence purposes only as allowed in this section (k...

  9. 36 CFR 242.28 - Subsistence taking of shellfish.

    Science.gov (United States)

    2010-07-01

    ... from buying or selling subsistence-taken shellfish, their parts, or their eggs, unless otherwise... currently identified under Federal subsistence management jurisdiction. (3) Cook Inlet Area. (i) You may...

  10. Surveillance of Hepatitis E Virus Contamination in Shellfish in China

    Directory of Open Access Journals (Sweden)

    Shenyang Gao

    2015-02-01

    Full Text Available Background: Hepatitis E virus (HEV has been confirmed to be a zoonotic virus of worldwide distribution. HEV contamination in the water environment has not been well examined in China. The objective of this study was to evaluate HEV contamination in shellfish in a coastal area of China. Such contamination would be significant for evaluating public health risks. Methods: samples of three species shellfish were collected from thirteen points of estuarine tidal flats around the Bohai Gulf and screened for HEV RNA using an in-house nested RT-PCR assay. The detected HEV-positive samples were further verified by gene cloning and sequencing analysis. Results: the overall HEV-positive detection rate is approximately 17.5% per kilogram of shellfish.  HEV was more common among S. subcrenata (28.2%, followed by A. granosa (14.3% and R. philippinarum (11.5%. The phylogenetic analysis of the 13 HEV strains detected revealed that gene fragments fell into two known 4 sub-genotypes (4b/4d groups and another unknown group. Conclusions: 13 different sub-genotype 4 HEVs were found in contaminated shellfish in the Bohai Gulf rim. The findings suggest that a health risk may exist for users of waters in the Bonhai area and to consumers of shellfish.  Further research is needed to assess the sources and infectivity of HEV in these settings, and to evaluate additional shellfish harvesting areas.

  11. [Cross reactivity between fish and shellfish].

    Science.gov (United States)

    Torres Borrego, J; Martínez Cuevas, J F; Tejero García, J

    2003-01-01

    In Spain, fish allergy represents 18 % of all cases of food allergy in children while reactions caused by crustacea and mollusks account for 3.8 % and 1.6 % respectively. Cross-reactivity is defined as the recognition of distinct antigens by the same IgE antibody, demonstrable by in vivo and in vitro tests, which clinically manifests as reactions caused by antigens homologous to different species. Subclinical sensitization can also occur, giving rise to patients sensitized to particular fish or shellfish but who do not present symptoms on consumption.Cod and shrimp have been the models used to study allergy to fish and crustacea respectively. The major allergens responsible for cross-reactivity among distinct species of fish and amphibians are proteins that control calcium flow in the muscular sarcoplasm of these animals, called parvalbumins, with a molecular weight of approximately 12 kD and an isoelectric point of 4.75, resistant to the action of heat and enzymatic digestion. Recently, recombinant carp parvalbumin has been reproduced, confirming that this allergen contains 70 % of the IgE epitopes present in natural extract of cod, tuna and salmon, which makes it a valid tool in the diagnosis of patients with fish allergy. Moreover, this recombinant allergen could constitute the basis for the development of immunotherapy against food allergy. In the case of shellfish, a non-taxonomic group that includes crustacea and mollusks, the major allergen is tropomyosin, an essential protein in muscle contraction both in invertebrates and vertebrates. In invertebrates, tropomyosins, which have a molecular weight of between 38 and 41 kD, show great homology in their amino acid sequence and are the panallergens responsible for cross-reactions between crustacea, insects, mites, nematodes, and different classes of mollusks. It is estimated that 50 % of individuals allergic to some type of fish are at risk for reacting to a second species, while those allergic to some type of

  12. Potential of irradiation technology for improved shellfish sanitation

    International Nuclear Information System (INIS)

    Mallett, J.C.; Beghian, L.E.; Metcalf, T.G.; Kaylor, J.D.

    1991-01-01

    Ionizing radiation is shown capable of serving as an effective sanitizing treatment improving the sanitary quality of shellfish and providing an increased margin of safety for shellfish consumers. 60Co irradiation of the hard-shelled clam, Mercenaria mercenaria, and the oyster, Crassostrea virginica, significantly reduced virus carriage numbers without unduly affecting shellfish survival rates or desirable organoleptic qualities. A D10 value of 2 kGy was determined for depletion of hepatitis A virus in clams and oysters as measured by in situ hybridization fluorescent foci and cytopathology enumeration methods. A D10 value of 2.4 kGy was determined for depletion of rotavirus SA11 in clams and oysters as measured by a plaque forming unit enumeration method. Study results showed ionizing radiation capable of providing an extra, highly effective safeguard of shellfish sanitary quality when combined with traditional depuration treatment. Data drawn from other studies is introduced which shows D10 values as low as 1.0 kGy effectively eliminate Vibrio cholerae, and V. parahemolyticus, from shellfish

  13. Shellfish Culture at the Milford Laboratory: hatchery production, stock enhancement and aquaculture research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Provide shellfish in support of Milford Lab efforts, external research projects and regional shellfish restoration. Conduct aquaculture experiments aimed at...

  14. Prevalence of Rotavirus in shellfish from Southern Kerala

    Directory of Open Access Journals (Sweden)

    Vysakh Mohan

    2014-10-01

    Full Text Available Aim: To study the prevalence of Rotavirus in shellfish from Southern Kerala. Materials and Methods: The shellfish samples after processing was concentrated using proteinase K. RNA was isolated from the concentrated samples using phenol chloroform method. Rota viral RNA was detected using reverse transcriptionpolymerase chain reaction. Results: A low prevalence of 2.5% (5/200 was obtained during the study. Rotavirus was detected in 2 out of 60 brown mussels (3.33%, 2 out of 70 yellow clams (2.86% and 1 out of 70 black clams (1.43%. Conclusion: Low prevalence of Rotavirus was obtained in our study. A more extensive study need to be conducted to estimate the prevalence of enteric virus in shellfish.

  15. Detection of hepatitis A in shellfish in Tunisia

    International Nuclear Information System (INIS)

    Zitouni, Moncef

    2008-01-01

    Our study was aimed at developing a method of extraction and concentration of hepatitis A. We used two methods T1 and T2 described previously in the literature. 23 samples shellfish from different area of Tunisia were included in this study. Technique T2 based only on glycine revealed the highest yield. The reverse transcription followed by polymerase chain reaction was performed in this study in order to investigate HAV in our samples. The results of molecular analyses of shellfish showed that 8.6% of the samples were contaminated. (Author)

  16. Concentration of PSP (Paralytic Shellfish Poisoning) Toxin On Shellfish From Inner Ambon Bay and Kao Bay North Halmahera

    Science.gov (United States)

    Pello, F. S.; Haumahu, S.; Huliselan, N. V.; Tuapattinaja, M. A.

    2017-10-01

    The Inner Ambon Bay and Kao Bay have potential on fisheries resources which one of them is molluscs. Molluscs especially for class bivalve have economical values and are consumed by coastal community. The research had been done to analyze saxitoxin (STX) concentration on bivalves from Kao Bay and Inner Ambon Bay. The Saxitoxin Elisa Test Kit Protocol was used to determine saxitoxin concentration. The measurement showed that the highest concentration of saxitoxin (392.42 µg STXeq/100g shellfish meat) was Gafrarium tumidum from Ambon Bay, whereas concentration of saxitoxin (321.83 µg STXeq/100g shellfish meat) was Mactra mera from Kao Bay

  17. Enteric porcine viruses in farmed shellfish in Denmark.

    Science.gov (United States)

    Krog, J S; Larsen, L E; Schultz, A C

    2014-09-01

    Bivalve shellfish are at constant risk of being exposed to pathogens as a consequence of contamination of the shellfish beds with human or animal waste originating from sewage treatment plants or slurry fertilized fields. Consumption of contaminated oysters and mussels are frequently reported as causes of disease outbreaks caused by norovirus or hepatitis A virus. Other zoonotic pathogens such as hepatitis E virus (HEV), rotavirus (RV) and Salmonella from livestock may also be transmitted to shellfish via this route. In this study, 29 pooled samples from commercial Danish blue mussels were tested for porcine pathogens and indicator bacteria Escherichia coli (E. coli). All samples tested negative for HEV, RV and Salmonella, whereas E. coli and the highly stable porcine circovirus type 2 (PCV2) were detected in eight and 12 samples, respectively. This is the first study to report the detection of PCV2 in commercial mussels. Based on the detection of PCV2 in clean areas with low prevalence of the normally applied fecal indicator E. coli, testing for PCV2 may be a more sensitive and robust specific porcine waste indicator in shellfish harvesting areas. Copyright © 2014. Published by Elsevier B.V.

  18. Dinophysis Toxins: Causative Organisms, Distribution and Fate in Shellfish

    Science.gov (United States)

    Reguera, Beatriz; Riobó, Pilar; Rodríguez, Francisco; Díaz, Patricio A.; Pizarro, Gemita; Paz, Beatriz; Franco, José M.; Blanco, Juan

    2014-01-01

    Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins) and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP), even at low cell densities (Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins), and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated. PMID:24447996

  19. Establishing a National Shellfish Sanitation Program in The Gambia ...

    African Journals Online (AJOL)

    The Tanbi Wetlands and other estuaries of Gambia support shellfisheries for oysters, Crassostrea tulipa, and the senile ark, Senelia senilis, conducted by the TRY Oyster Women's ... Since August 2010, water was sampled bimonthly for total (TC) and fecal coliforms (FC) at stations near shellfish harvesting areas. Sanitary ...

  20. Dinophysis Toxins: Causative Organisms, Distribution and Fate in Shellfish

    Directory of Open Access Journals (Sweden)

    Beatriz Reguera

    2014-01-01

    Full Text Available Several Dinophysis species produce diarrhoetic toxins (okadaic acid and dinophysistoxins and pectenotoxins, and cause gastointestinal illness, Diarrhetic Shellfish Poisoning (DSP, even at low cell densities (<103 cells·L−1. They are the main threat, in terms of days of harvesting bans, to aquaculture in Northern Japan, Chile, and Europe. Toxicity and toxin profiles are very variable, more between strains than species. The distribution of DSP events mirrors that of shellfish production areas that have implemented toxin regulations, otherwise misinterpreted as bacterial or viral contamination. Field observations and laboratory experiments have shown that most of the toxins produced by Dinophysis are released into the medium, raising questions about the ecological role of extracelular toxins and their potential uptake by shellfish. Shellfish contamination results from a complex balance between food selection, adsorption, species-specific enzymatic transformations, and allometric processes. Highest risk areas are those combining Dinophysis strains with high cell content of okadaates, aquaculture with predominance of mytilids (good accumulators of toxins, and consumers who frequently include mussels in their diet. Regions including pectenotoxins in their regulated phycotoxins will suffer from much longer harvesting bans and from disloyal competition with production areas where these toxins have been deregulated.

  1. Natural modulators of Vibrios in seawater and shellfish

    Science.gov (United States)

    Naturally occurring marine bacteria, Vibrio parahaemolyticus and V. vulnificus, are major threats to the safety of molluscan shellfish in the US and elsewhere. Illnesses range from mild gastrointestinal upset to septicemia and death. In studies on the uptake and persistence of V. parahaemolyticus ...

  2. Enteric porcine viruses in farmed shellfish in Denmark

    DEFF Research Database (Denmark)

    Krog, Jesper Schak; Larsen, Lars Erik; Schultz, Anna Charlotte

    2014-01-01

    as causes of disease outbreaks caused by norovirus or hepatitis A virus. Other zoonotic pathogens such as hepatitis E virus (HEV), rotavirus (RV) and Salmonella from livestock may also be transmitted to shellfish via this route. In this study, 29 pooled samples from commercial Danish blue mussels were...

  3. Australian shellfish ecosystems: Past distribution, current status and future direction.

    Directory of Open Access Journals (Sweden)

    Chris L Gillies

    Full Text Available We review the status of marine shellfish ecosystems formed primarily by bivalves in Australia, including: identifying ecosystem-forming species, assessing their historical and current extent, causes for decline and past and present management. Fourteen species of bivalves were identified as developing complex, three-dimensional reef or bed ecosystems in intertidal and subtidal areas across tropical, subtropical and temperate Australia. A dramatic decline in the extent and condition of Australia's two most common shellfish ecosystems, developed by Saccostrea glomerata and Ostrea angasi oysters, occurred during the mid-1800s to early 1900s in concurrence with extensive harvesting for food and lime production, ecosystem modification, disease outbreaks and a decline in water quality. Out of 118 historical locations containing O. angasi-developed ecosystems, only one location still contains the ecosystem whilst only six locations are known to still contain S. glomerata-developed ecosystems out of 60 historical locations. Ecosystems developed by the introduced oyster Crasostrea gigas are likely to be increasing in extent, whilst data on the remaining 11 ecosystem-forming species are limited, preventing a detailed assessment of their current ecosystem-forming status. Our analysis identifies that current knowledge on extent, physical characteristics, biodiversity and ecosystem services of Australian shellfish ecosystems is extremely limited. Despite the limited information on shellfish ecosystems, a number of restoration projects have recently been initiated across Australia and we propose a number of existing government policies and conservation mechanisms, if enacted, would readily serve to support the future conservation and recovery of Australia's shellfish ecosystems.

  4. Fish, shellfish, and meat meals of the public in Singapore

    International Nuclear Information System (INIS)

    Burger, Joanna; Fleischer, Jennifer; Gochfeld, Michael

    2003-01-01

    Understanding different patterns of fish consumption is an important component of the assessment of risk from contaminants in fish. While there have been extensive studies of fish consumption in Western cultures, less attention has been devoted to the role of fish and meat in the diets of people in other cultures. A survey of 212 people living in Singapore was conducted to examine the relative importance of fish, shellfish, and other meat in their diets and to ascertain whether there were differences as a function of age, income, education or gender. As expected, fish and shellfish played an important role in their daily diets. On average, people ate fish in about 10 meals a week, chicken for eight meals, and shrimp and pork for about six meals each. While nearly 8% never ate fish, 18% ate fish at all 21 meals a week and over 20% ate shellfish for all 21 meals. Income explained about 14% of the variation in the number of fish meals consumed, and age explained about 8% of the variation in number of chicken meals per week. There were no gender differences in the number of meals of each type. People less than 26 years old ate significantly more pork, chicken, and other meat meals and fewer shellfish meals than older people. People with higher incomes ate significantly more fish meals than those with lower incomes. Chinese individuals ate significantly more meals of pork, chicken, and other meat than other ethnic groups, and they ate only 26% of their meals at home, while others ate 33% of their meals at home. The data indicate a great deal of variation in the number of meals of fish, shellfish, and other meats eaten by the people interviewed, making dietary and risk assessments challenging

  5. Australian shellfish ecosystems: Past distribution, current status and future direction

    Science.gov (United States)

    Gillies, Chris L.; McLeod, Ian M.; Alleway, Heidi K.; Cook, Peter; Crawford, Christine; Creighton, Colin; Diggles, Ben; Ford, John; Hamer, Paul; Heller-Wagner, Gideon; Lebrault, Emma; Le Port, Agnès; Russell, Kylie; Sheaves, Marcus; Warnock, Bryn

    2018-01-01

    We review the status of marine shellfish ecosystems formed primarily by bivalves in Australia, including: identifying ecosystem-forming species, assessing their historical and current extent, causes for decline and past and present management. Fourteen species of bivalves were identified as developing complex, three-dimensional reef or bed ecosystems in intertidal and subtidal areas across tropical, subtropical and temperate Australia. A dramatic decline in the extent and condition of Australia’s two most common shellfish ecosystems, developed by Saccostrea glomerata and Ostrea angasi oysters, occurred during the mid-1800s to early 1900s in concurrence with extensive harvesting for food and lime production, ecosystem modification, disease outbreaks and a decline in water quality. Out of 118 historical locations containing O. angasi-developed ecosystems, only one location still contains the ecosystem whilst only six locations are known to still contain S. glomerata-developed ecosystems out of 60 historical locations. Ecosystems developed by the introduced oyster Crasostrea gigas are likely to be increasing in extent, whilst data on the remaining 11 ecosystem-forming species are limited, preventing a detailed assessment of their current ecosystem-forming status. Our analysis identifies that current knowledge on extent, physical characteristics, biodiversity and ecosystem services of Australian shellfish ecosystems is extremely limited. Despite the limited information on shellfish ecosystems, a number of restoration projects have recently been initiated across Australia and we propose a number of existing government policies and conservation mechanisms, if enacted, would readily serve to support the future conservation and recovery of Australia’s shellfish ecosystems. PMID:29444143

  6. Consumer Attitude Towards Shellfish In The Greek Market: A Pilot Study

    Directory of Open Access Journals (Sweden)

    CH. BATZIOS

    2003-12-01

    Full Text Available During the last decade, the Greek shellfish industry has experienced significant changes affecting both the market demand and the availability of the end products. Although, shellfish and seafood in general have been promoted as healthy food by marketing boards and private seafood companies in many countries all over the world, no attention has been paid so far to analysing the Greek consumer’s purchasing behaviour and attitudes towards the shellfish market. This paper presents the results of the first survey in this field of research, which was carried out in northern Greece (area of Katerini and Greater Thessaloniki from January to March 2002. A randomly selected sample of 400 consumers filled in a questionnaire, which covered basic marketing aspects of shellfish consumption such as choice, purchase, reasons for consuming shellfish, confidence in shellfish hygiene certification, media influence, etc. Data analysis includes descriptive statistics, as well as chi-square (― 2 tests (crosstabulation to examine possible relations between consumers’ demographic and socio-economic characteristics and shellfish marketing aspects. Analyses of the results have shown that the majority of Greek consumers prefer the exploitable to cultured shellfish and in general do not eat shellfish often. They prefer the traditional fish shops for purchasing shellfish and consume them mainly in summer. The strongest reason to buy shellfish is their taste, while freshness is considered as the most important criterion when deciding to buy shellfish. Moreover, the vast majority of the consumers prefer a certification of quality, trust the confirmation provided by the veterinary authorities, but do not prefer ready-to-eat shellfish. Results revealed that consumers’ behaviour and attitudes vary considerably according to their demographic and socio-economic characteristics. The results of this study could prove to be helpful for decision makers towards a more rational

  7. Native Shellfish in Nearshore Ecosystems of Puget Sound

    Science.gov (United States)

    2006-04-01

    California Dungeness crabs (Cancer magister). California Fish and Game 63:43-51. Griffin, K. 1997. Commercial oyster cultivation and eelgrass...A.M. 2007. Great Blue Herons in Puget Sound. Puget Sound Nearshore Partnership Report No. 2007-06. Published by Seattle District, U.S. Army Corps of...non-native Pacific oyster, but more than $40 million is from native crabs , clams, and mussels. Recreationally, personal harvest of shellfish is a

  8. Potentiometric chemical sensors for the detection of paralytic shellfish toxins.

    Science.gov (United States)

    Ferreira, Nádia S; Cruz, Marco G N; Gomes, Maria Teresa S R; Rudnitskaya, Alisa

    2018-05-01

    Potentiometric chemical sensors for the detection of paralytic shellfish toxins have been developed. Four toxins typically encountered in Portuguese waters, namely saxitoxin, decarbamoyl saxitoxin, gonyautoxin GTX5 and C1&C2, were selected for the study. A series of miniaturized sensors with solid inner contact and plasticized polyvinylchloride membranes containing ionophores, nine compositions in total, were prepared and their characteristics evaluated. Sensors displayed cross-sensitivity to four studied toxins, i.e. response to several toxins together with low selectivity. High selectivity towards paralytic shellfish toxins was observed in the presence of inorganic cations with selectivity coefficients ranging from 0.04 to 0.001 for Na + and K + and 3.6*10 -4 to 3.4*10 -5 for Ca 2+ . Detection limits were in the range from 0.25 to 0.9 μmolL -1 for saxitoxin and decarbamoyl saxitoxin, and from 0.08 to 1.8 μmolL -1 for GTX5 and C1&C2, which allows toxin detection at the concentration levels corresponding to the legal limits. Characteristics of the developed sensors allow their use in the electronic tongue multisensor system for simultaneous quantification of paralytic shellfish toxins. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Evaluating shellfish gathering ( Lucina pectinata) in a tropical mangrove system

    Science.gov (United States)

    Rondinelli, S. F.; Barros, F.

    2010-10-01

    Fish resources are important sources of income and protein to traditional inhabitants of coastal zones. In Garapuá village, the shellfish Lucina pectinata is the main resource exploited in mangroves. This study tests whether if in less explored areas (far from the village) L. pectinata individuals have higher densities and greater lengths, and if there was a decrease in cpue's over the last years. Samples were taken monthly in two habitats (mangrove channels and mangrove roots) in six mangrove areas by random squares. The results indicated that closer areas showed significantly lower densities than areas far from the village. Densities were significantly higher in mangrove roots (quizangas) than at channels. There was a significant increase in monthly L. pectinata cpue, from 18.2 dz./shellfish gatherers/day in 2001 to 19.3 in 2007, showing that this stock does not seem to be overexploited. However, (i) a long-term monitoring of Garapuá shellfish gatherers to evaluate if the stock will support an increasing pressure and (ii) several manipulative experiments to better understand ecological processes are suggested.

  10. VISION, STRATEGY AND ACTION PLAN FOR SHELLFISH FARMING DEVELOPMENT IN THE KRKA RIVER ESTUARY

    Directory of Open Access Journals (Sweden)

    Drago Maguš

    2009-10-01

    Full Text Available In this paper are presented the vision, strategic guidelines/measures and the action plan for shellfish farming development in the Krka river estuary. They came as a result from several discussions that were held with shellfish farmers of the estuary area in year 2008 while writing the Integrated Plan for Shellfish Farming for Krka Estuary Area, which was realized in the framework of the Green Business Support Programme (UNDP COST Project — Conservation, and Sustainable Use of Biodiversity in the Dalmatian Coast through Greening Coastal Development. For a short–term, a considerable impetus for the development of shellfish farming in the Krka river estuary could be the construction of common distribution and purification center, building of warehouse for shellfish farming equipment, and providing work space for the preparation of the equipment as well as the space for waste disposal; for a long–term it could be building of shellfish hatchery at the location of Martinska marine station.

  11. Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish

    Directory of Open Access Journals (Sweden)

    Christopher Elliott

    2011-01-01

    Full Text Available Paralytic shellfish poisoning (PSP is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20–300 ng/mL, incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis.

  12. Intertidal Concentrations of Microplastics and Their Influence on Ammonium Cycling as Related to the Shellfish Industry.

    Science.gov (United States)

    Cluzard, Melanie; Kazmiruk, Tamara N; Kazmiruk, Vasily D; Bendell, L I

    2015-10-01

    Microplastics are ubiquitous within the marine environment. The last 10 years have seen research directed at understanding the fate and effect of microplastics within the marine environment; however, no studies have yet addressed how concentrations of these particles could affect sedimentary processes such as nutrient cycling. Herein we first determine the concentration and spatial distribution of microplastics within Baynes Sound, a key shellfish-growing area within coastal British Columbia (BC). We also determined sediment grain size and % organic matter (OM) such that we could relate spatial patterns in sediment microplastic concentrations to sedimentary processes that determine zones of accretion and erosion. Using field-determined concentrations of microplastics, we applied laboratory microcosms studies, which manipulated sediment concentrations of microplastics, OM, and bivalves to determine the influence of sediment microplastics on ammonium cycling within intertidal sediments. Concentrations of microplastics determined within the intertidal sediment varied spatially and were similar to those found in other coastal regions of high urban use. Concentrations were independent of grain size and OM suggesting that physical processes other than those that govern natural sediment components determine the fate of microplastics within sediments. Under laboratory conditions, concentrations of ammonium were significantly greater in the overlying water of treatments with microplastics, clams, and OM compared with treatments without microplastics. These preliminary studies suggest that high concentrations of microplastics have the potential to alter key sedimentary processes such as ammonium flux. This could have serious implications, for example, contributing to eutrophication events in regions of the coast that are highly urbanized.

  13. Does traditional shellfishing affect foraging by waders? The case of the Tagus estuary (Portugal)

    Science.gov (United States)

    Dias, Maria P.; Peste, Filipa; Granadeiro, José P.; Palmeirim, Jorge M.

    2008-03-01

    Estuarine intertidal flats are often exploited by humans and waders since they provide food, particularly shellfish. This raises important conservation issues. Waders can be affected by shellfishing activities in multiple ways, such as a reduction of the available shellfish, disturbance by the presence of shellfishers on their feeding areas, and changes in micro-habitat, due to sediment reworking. In this study we quantified the impact of traditional shellfishing on waders in the Tagus estuary. Particular attention was given to hand-raking of clams Scrobicularia plana, which constitutes most of the consumed food by waders. Shellfishers did not cause a relevant depletion of clams for waders; they removed less than 0.3% of its total production and focused on size classes that were usually not taken by birds. Hand-raking caused temporary changes in the vertical distribution and availability of invertebrate prey in the sediment. However, this did not affect the bird's feeding rates, presumably because prey availability remained above the threshold at which intake rates are expected to decline. The presence of shellfishers in the birds foraging areas potentially affects waders by keeping them away from foraging areas, but even the most affected species lost less than 10% of their foraging grounds due to this factor. Overall, we conclude that the current low harvesting levels of shellfishing are compatible with the preservation of the estuary as a key site for waders. Nevertheless, simulations showed that traditional shellfishing could have much greater potential to affect waders through disturbance than through prey removal. The results for the Tagus show that even small harvest rates, representing a negligible loss of food for waders and potentially considered sustainable by shellfish managers, could have a great impact on waders due to increased disturbance. This effect of disturbance likely occurs in most estuaries and should be taken into consideration when planning

  14. Characterization of the NIST shellfish Standard Reference Material 4358

    International Nuclear Information System (INIS)

    Nour, S.; Inn, K.G.W.; Filliben, J.; Gaast van der, H.; Men, L.C.; Calmet, D.; Altzitzoglou, T.; Povinec, P.; Takata, Y.; Wisdom, M.

    2013-01-01

    A new shellfish Standard Reference Material 4358 was developed by the National Institute of Standards and Technology through an international interlaboratory comparison that involved twelve laboratories-participants from nine countries. The results from the participants were statistically evaluated, and the most robust certified values were based on the median of laboratories’ reported means and the uncertainties derived using the bootstrap method. Massic activity certified values were established for fourteen radionuclides, five activity ratios, and informational massic activity values for eight more radionuclides and two activity ratios. (author)

  15. Lipophilic Toxins in WA - Clear and present danger: monitoring and management of lipophilic shellfish toxins in Washington State

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lipophilic shellfish toxins comprise an extensive suite of compounds including those associated with the human syndromes known as diarrhetic shellfish poisoning...

  16. Data from monitoring of shellfish for Paralytic Shellfish Poisoning (PSP) and Domoic Acid Poisoning (DAP) by the Washington State Department of Health, 1989-1999 (NODC Accession 0000580)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The state of Washington routinely experiences seasonal restrictions on commercial and recreational shellfish harvest due to two toxic phytoplankton syndromes,...

  17. Sampling for Paralytic Shellfish Poisoning in commercial and recreational shellfish areas in Washington state marine waters, 1957 - 1988 (NODC Accession 0000597)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The state of Washington routinely experiences seasonal restrictions on commercial and recreational shellfish harvest due to two toxic phytoplankton syndromes,...

  18. Sampling for Paralytic Shellfish Poisoning in commercial and recreational shellfish areas in Washington state marine waters, January - December 2000 (NODC Accession 0000559)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The state of Washington routinely experiences seasonal restrictions on commercial and recreational shellfish harvest due to two toxic phytoplankton syndromes,...

  19. International Standardisation of a Method for Detection of Human Pathogenic Viruses in Molluscan Shellfish

    DEFF Research Database (Denmark)

    Lees, David; Schultz, Anna Charlotte

    2010-01-01

    The viruses primarily associated with shellfish-borne illness are norovirus, causing gastroenteritis and hepatitis A virus (HAV). Recent years have seen a proliferation of publications on methods for detection of these viruses in shellfish using polymerase chain reaction (PCR). However, currently...

  20. Shellsim: A Generic Model of Growth and Environmental Effects Validated Across Contrasting Habitats in Bivalve Shellfish

    NARCIS (Netherlands)

    Hawkins, A.; Pascoe, P.L.; Parry, H.; Brinsley, M.; Black, K.; McGonigle, C.; Smaal, A.C.

    2013-01-01

    Previous shellfish models have, in general, been calibrated for 1 location, unable to simulate growth across habitats that contrast in seston abundance and composition, as may vary between turbid, eutrophic and oligotrophic waters. Here, we describe the generic shellfish model ShellSIM,

  1. New molecular methods for the detection of hepatitis A and Norwalk viruses in shellfish.

    Science.gov (United States)

    Romalde, J L

    1996-12-01

    Outbreaks of viral enteric diseases after consumption of shellfish are a major health risk. Methodological problems (such as toxicity for cell cultures and low viral concentrations) and the unculturability of some strains (i.e. hepatitis A virus, Norwalk virus) have made it difficult to study those viruses in the environmental samples. Currently, the analysis of the hygienic quality of marketable shellfish is determined by the use of fecal indicator bacteria, but their reliability in determining viral pollution of shellfish is very low. Recent biotechnology developments are providing available rapid, sensitive, and specific tools for detecting food-borne viruses in shellfish and in shellfish-growing waters. In this paper, a review of these new molecular methods is carried out, discussing their advantages and possible applications.

  2. Recent trends in paralytic shellfish toxins in Puget Sound, relationships to climate, and capacity for prediction of toxic events

    Science.gov (United States)

    Stephanie K. Moore; Nathan J. Mantua; Barbara M. Hickey; Vera L. Trainer

    2009-01-01

    Temporal and spatial trends in paralytic shellfish toxins (PSTs) in Puget Sound shellfish and their relationships with climate are investigated using long-term monitoring data since 1957. Data are selected for trend analyses based on the sensitivity of shellfish species to PSTs and their depuration rates, and the frequency of sample collection at individual sites....

  3. Selective accumulation may account for shellfish-associated viral illness.

    Science.gov (United States)

    Burkhardt, W; Calci, K R

    2000-04-01

    From 1991 through 1998, 1,266 cases of shellfish-related illnesses were attributed to Norwalk-like viruses. Seventy-eight percent of these illnesses occurred following consumption of oysters harvested from the Gulf Coast during the months of November through January. This study investigated the ability of eastern oysters (Crassostrea virginica) to accumulate indicator microorganisms (i.e., fecal coliforms, Escherichia coli, Clostridium perfringens, and F(+) coliphage) from estuarine water. One-week trials over a 1-year period were used to determine if these indicator organisms could provide insight into the seasonal occurrence of these gastrointestinal illnesses. The results demonstrate that oysters preferentially accumulated F(+) coliphage, an enteric viral surrogate, to their greatest levels from late November through January, with a concentration factor of up to 99-fold. However, similar increases in accumulation of the other indicator microorganisms were not observed. These findings suggest that the seasonal occurrence of shellfish-related illnesses by enteric viruses is, in part, the result of seasonal physiological changes undergone by the oysters that affect their ability to accumulate viral particles from estuarine waters.

  4. Enteric viruses in a mangrove lagoon, survival and shellfish incidence

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Cardona, I.; Bermudez, M.; Billmire, E.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

    1988-12-31

    Mangrove oysters (Crassostrea rhizophorae) were screened for enteric viruses. For 18 months oysters were collected from Cano Boqueron, a tropical mangrove lagoon on the southwest coast of Puerto Rico. This popular tourist resort has two primary sewage treatment plants which service 158 single family cabanas. In spite of the heavy seasonal input of sewage to Cano Boqueron and high densities of fecal coliform bacteria, enteric viruses were not detected in shellfish meat. Because no viruses were detected in the oysters, a virus survival study was performed. Poliovirus type 1 was placed in diffusion chambers in situ at two sites in Cano Boqueron. More than 95% of the poliovirus inactivation occurred within 24 h. Virus inactivation was significantly different by site, indicating different inactivation rates within the lagoon. Chamber studies done simultaneously with Escherichia coli did not reveal differences between sites. It is suggested that the sewage effluent had an antiviral effect in the absence of an antibacterial effect. This study demonstrates the importance for establishing microbial contamination standards for shellfish growing waters in the tropics based upon in situ studies with tropical species, e.g. mangrove oyster.

  5. Shellfish Fishery Severely Reduces Condition and Survival of Oystercatchers Despite Creation of Large Marine Protected Areas

    Directory of Open Access Journals (Sweden)

    Simon Verhulst

    2004-06-01

    Full Text Available Fisheries and other human activities pose a global threat to the marine environment. Marine protected areas (MPAs are an emerging tool to cope with such threats. In the Dutch Wadden Sea, large MPAs (covering 31% of all intertidal flats have been created to protect shellfish-eating birds and allow recovery of important habitats. Even though shellfish fishing is prohibited in these areas, populations of shellfish-eating birds in the Wadden Sea have declined sharply. The role of shellfish fisheries in these declines is hotly debated, therefore, we investigated the effectiveness of MPAs for protecting oystercatcher (Haematopus ostralegus populations. Shellfish stocks (cockles, Cerastoderma edule were substantially higher in the MPAs, but surprisingly this has not resulted in a redistribution of wintering oystercatchers. Oystercatchers in unprotected areas had less shellfish in their diet and lower condition (a combined measure of mass and haematological parameters, and their estimated mortality was 43% higher. It is likely, therefore, that shellfish fishing explains at least part of the 40% decline in oystercatcher numbers in recent years. Condition and mortality effects were strongest in males, and the population sex ratio was female biased, in agreement with the fact that males rely more on shellfish. The unprotected areas apparently function as an "ecological trap," because oystercatchers did not respond as anticipated to the artificial spatial heterogeneity in food supply. Consequently, the MPAs are effective on a local scale, but not on a global scale. Similar problems are likely to exist in terrestrial ecosystems, and distribution strategies of target species need to be considered when designing terrestrial and marine protected areas if they are to be effective.

  6. Marker-assisted selection in fish and shellfish breeding schemes

    International Nuclear Information System (INIS)

    Martinez, V.

    2007-01-01

    The main goals of breeding programmes for fish and shellfish are to increase the profitability and sustainability of aquaculture. Traditionally, these have been carried out successfully using pedigree information by selecting individuals based on breeding values predicted for traits measured on candidates using an 'animal model'. This methodology assumes that phenotypes are explained by a large number of genes with small effects and random environmental deviations. However, information on individual genes with medium or large effects cannot be used in this manner. In selective breeding programmes using pedigree information, molecular markers have been used primarily for parentage assignment when tagging individual fish is difficult and to avoid causing common environmental effects from rearing families in separate tanks. The use of these techniques in such conventional breeding programmes is discussed in detail. Exploiting the great biological diversity of many fish and shellfish species, different experimental designs may use either chromosomal manipulations or large family sizes to increase the likelihood of finding the loci affecting quantitative traits, the so-called QTL, by screening the segregation of molecular markers. Using information on identified loci in breeding schemes in aquaculture is expected to be cost-effective compared with traditional breeding methods only when the accuracy of predicting breeding values is rather low, e.g. for traits with low heritability such as disease resistance or carcass quality. One of the problems facing aquaculture is that some of the resources required to locate QTL accurately, such as dense linkage maps, are not yet available for the many species. Recently, however, information from expressed sequence tag (EST) databases has been used for developing molecular markers such as microsatellites and single nucleotide polymorphisms (SNPs). Marker-assisted selection (MAS) or genome-wide marker-assisted selection (G-MAS) using

  7. Surveillance of hepatitis A and E viruses contamination in shellfish in Thailand.

    Science.gov (United States)

    Namsai, A; Louisirirotchanakul, S; Wongchinda, N; Siripanyaphinyo, U; Virulhakul, P; Puthavathana, P; Myint, K S; Gannarong, M; Ittapong, R

    2011-12-01

    To survey for hepatitis A virus (HAV) and hepatitis E virus (HEV) contamination in edible bivalve shellfish. A total of 213 shellfish (52 oysters, 69 cockles and 92 mussels) collected from a culture farm and two retailed markets were investigated for HAV and HEV contamination by reverse transcription-polymerase chain reaction (RT-PCR) assay using HA2-HA1 (capsid region) and HE366-HE363 (ORF2/3 overlapping region) primers, respectively. It was found that 3.8% of the shellfish and 2.9 and 6.5% of the cockle and mussel, respectively, showed positive for HAV detection. Nucleotide sequencing of all the 8 HAV-positive shellfish revealed 97-100% similarity to HAV subgenotype IA. Interestingly, viruses were found more frequently in the gills than in digestive tissue (4.5%vs 0.5%, P = 0.045). All the shellfish were negative for HEV. Significant contamination of HAV in edible bivalve shellfish was observed. Beside digestive tissue, gills are one of the important samples for viral genome detection. HAV-contaminated shellfish can play a role as reservoirs and/or vehicles in faecal-oral transmission in Thailand, and further monitoring of such a contamination is required. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  8. Sensory and Physical Assessment of Microbiologically Safe Culinary Processes for Fish and Shellfish

    OpenAIRE

    Felice, Renee Jacqueline

    2011-01-01

    Numerous food-borne illnesses are associated with fish and shellfish annually due to consumers choosing to eat seafood raw or undercooked and consumers not properly handling and preparing seafood. The 2009 FDA Food Code suggests intact fish and shellfish should be cooked to an internal temperature of 63°C to target Salmonella spp. Selected fish and shellfish were cooked to 64°C ± 1 and 74°C ± 1 and evaluated for consumer acceptability, characteristics of doneness at temperature endpoints...

  9. Food Safety Impacts from Post-Harvest Processing Procedures of Molluscan Shellfish.

    Science.gov (United States)

    Baker, George L

    2016-04-18

    Post-harvest Processing (PHP) methods are viable food processing methods employed to reduce human pathogens in molluscan shellfish that would normally be consumed raw, such as raw oysters on the half-shell. Efficacy of human pathogen reduction associated with PHP varies with respect to time, temperature, salinity, pressure, and process exposure. Regulatory requirements and PHP molluscan shellfish quality implications are major considerations for PHP usage. Food safety impacts associated with PHP of molluscan shellfish vary in their efficacy and may have synergistic outcomes when combined. Further research for many PHP methods are necessary and emerging PHP methods that result in minimal quality loss and effective human pathogen reduction should be explored.

  10. Discover the Atlantic Ocean: An Exciting Coloring Book of Fish and Shellfish.

    Science.gov (United States)

    Flick, George J.

    This coloring book contains pictures of more than 79 fish and shellfish found on the Atlantic Coast. Captions give information on habitats, behavior, or commercial uses of the species pictured. Indexes of both common and scientific names are given. (BB)

  11. Effects of hydraulic shellfish harvesting on benthic communities and sediment chemistry 2009-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effects of hydraulic shellfish harvesting on the ecology of biological communities and chemistry of benthic sediments were investigated through a series of...

  12. High pressure processing of bivalve shellfish and HPP's potential use as a virus intervention

    Science.gov (United States)

    Bivalve shellfish readily bioconcentrate pathogenic microbes and substance, such as algal and dinoflagulate toxins, fecal viruses and bacteria, and naturally present vibrio bacteria. High pressure processing (HPP) is currently used as an intervention for Vibrio vulnificus bacteria within molluscan ...

  13. Assessment of Current Guidelines for Culinary Preparation Methods of Fish and Shellfish

    OpenAIRE

    Kostal, Jeri Elizabeth

    2012-01-01

    Consumers regularly decide to consume fish and shellfish raw or undercooked, which can cause foodborne illness due to product contamination or unsafe handling by the consumer.  In order to be considered safe for consumption, intact fish and shellfish should be prepared to an internal temperature of 63"C, according to the 2009 FDA Food Code, with Salmonella spp. as the target organism.  Focus groups (5 groups, 32 participants) were conducted to determine consumer beliefs and concerns regarding...

  14. Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish.

    OpenAIRE

    Hood, M A; Ness, G E; Blake, N J

    1983-01-01

    The relationship of fecal coliforms, Escherichia coli, and Salmonella spp. was examined in freshly harvested and stored shellfish. In 16 of 40 freshly collected oyster samples, fecal coliform levels were above the recommended wholesale level suggested by the National Shellfish Sanitation Program (less than or equal to 230/100 g), and Salmonella spp. were present in three of these samples. Salmonella spp. were not, however, present in any sample containing less than 230 fecal coliforms per 100...

  15. Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish

    International Nuclear Information System (INIS)

    Mauffret, A.; Mieszkin, S.; Morizur, M.; Alfiansah, Y.; Lozach, S.; Gourmelon, M.

    2013-01-01

    Highlights: ► DNA extraction from intravalvular liquid is promising for microbial source tracking in oysters. ► Host-associated bacterial markers in shellfish digestive tissues were difficult to assess with real-time PCR. ► DNA extracts from shellfish flesh appeared to have low inhibitor levels but low marker levels. ► Protocol transfer from one shellfish species to another does not appear possible. -- Abstract: We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish

  16. Domoic Acid - A New Toxin in the Croatian Adriatic Shellfish Toxin Profile

    Directory of Open Access Journals (Sweden)

    Ivona Marasović

    2010-10-01

    Full Text Available This is the first study that presents concentrations of domoic acid detected in the whole shellfish tissue from breeding and harvesting areas along the Croatian coast of the Adriatic Sea during the period 2006 to 2008. Shellfish sample analyses after SAX cleaning procedures, using a UV-DAD-HPLC system, showed the presence of domoic acid in four species. The most prevalent of those species were the blue mussel (Mytilus galloprovincialis, followed by European flat oyster (Ostrea edulis, Mediterranean scallop (Pecten jacobaeus and proteus scallop (Flexopecten proteus. Domoic acid, a potentially lethal phycotoxin that causes amnesic shellfish poisoning (ASP, was detected for the first time in January 2006 with the highest value of 6.5486 μg g-1 in whole shellfish tissue. Pseudo-nitzschia spp. bloom events preceded these high domoic acid concentrations. According to this study, retention of domoic acid in the blue mussel M. galloprovincialis is more than 42 days. This investigation indicates the first presence of domoic acid in Croatian shellfish, but in concentrations under the regulatory limit (20 μg g-1, therefore shellfish consumption was not found to endanger human health.

  17. Attitudinal Factors and Personal Characteristics Influence Support for Shellfish Aquaculture in Rhode Island (US) Coastal Waters.

    Science.gov (United States)

    Dalton, Tracey M; Jin, Di

    2018-05-01

    This study explores public interests associated with shellfish aquaculture development in coastal waters of Rhode Island (US). Specifically, we examine (1) the levels of public support for (or opposition to) shellfish aquaculture development and (2) factors driving the levels of support, using survey data and ordinal logistic regressions. Results of the analysis identify several key attitudinal factors affecting individual's support for shellfish aquaculture in Rhode Island (RI). The level of support is positively associated with attitudes related to shellfish aquaculture's benefits to the local economy and its role as a nutritional food option, and negatively influenced by attitudes related to aquaculture farms' effects on aesthetic quality and their interference with other uses. Findings highlight that support for (or opposition to) aquaculture in RI is driven more by attitudes associated with social impacts than by those associated with environmental impacts. The level of support is also affected by personal characteristics related to an individual's participation in recreational activities. For instance, bicycle riders tend to be supportive of shellfish aquaculture while respondents who participate in sailing and birding are less supportive. By identifying the broader public's interests in shellfish aquaculture, findings from this study and others like it can be used to address public concerns, incorporate public perceptions and attitudes into permitting decisions, and develop outreach targeted at specific stakeholder groups.

  18. Committed effective dose from naturally occuring radionuclides in shellfish

    International Nuclear Information System (INIS)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D.A.

    2013-01-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238 U ( 226 Ra), 232 Th ( 228 Ra) and 40 K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg −1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg −1 . The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg −1 for 238 U ( 226 Ra), 0.16 Bq kg −1 for 232 Th ( 228 Ra) and 18 Bq kg −1 for 40 K; the respective daily intake values from crustaceans are 0.36 Bq kg −1 , 0.16 Bq kg −1 and 23 Bq kg −1 . Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226 Ra, 19.3 to 39.1 μSv for 228 Ra and 17.0 to 40.4 μSv for 40 K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values. - Highlights: ► Activity concentrations of naturally occuring radionuclides were assessed for shellfish. ► 238 U, 232 Th, 40 K intake via shellfish showed several times higher than world averages. ► Committed effective doses due to the ingestions of 238 U, 232 Th, 40 K are the first report in Malaysia. ► Estimated committed effective dose also showed higher values than the world average

  19. Disease Resistant Fish and Shellfish Are within Reach: A Review

    Directory of Open Access Journals (Sweden)

    Trygve Gjedrem

    2015-03-01

    Full Text Available Disease in fish and shellfish is one of the main problems facing aquaculture production. Therefore, all attempts should be made to increase the rate of survival and, thus, reduce economic losses. Much has been done to develop vaccines and medical treatments to reduce mortality; and however, farming of aquatic species has a long way to go to optimize the environmental conditions for the animals and, thus, reduce stress and improve animal welfare. However, the good news is that there is the potential to increase disease resistance by selective breeding. By challenge-testing fingerlings from a number of families per generation, and including the rate of survival in the breeding goal, the results so far are very promising. By focusing on one disease at a time it is possible to increase the rate of survival by at least 12.5% per generation for most diseases studied. Unfortunately, selective breeding is only used to a small degree in aquatic species. In 2010, it was estimated that only 8.2% of aquaculture production was based on genetically improved stocks.

  20. A model for estimating pathogen variability in shellfish and predicting minimum depuration times.

    Science.gov (United States)

    McMenemy, Paul; Kleczkowski, Adam; Lees, David N; Lowther, James; Taylor, Nick

    2018-01-01

    Norovirus is a major cause of viral gastroenteritis, with shellfish consumption being identified as one potential norovirus entry point into the human population. Minimising shellfish norovirus levels is therefore important for both the consumer's protection and the shellfish industry's reputation. One method used to reduce microbiological risks in shellfish is depuration; however, this process also presents additional costs to industry. Providing a mechanism to estimate norovirus levels during depuration would therefore be useful to stakeholders. This paper presents a mathematical model of the depuration process and its impact on norovirus levels found in shellfish. Two fundamental stages of norovirus depuration are considered: (i) the initial distribution of norovirus loads within a shellfish population and (ii) the way in which the initial norovirus loads evolve during depuration. Realistic assumptions are made about the dynamics of norovirus during depuration, and mathematical descriptions of both stages are derived and combined into a single model. Parameters to describe the depuration effect and norovirus load values are derived from existing norovirus data obtained from U.K. harvest sites. However, obtaining population estimates of norovirus variability is time-consuming and expensive; this model addresses the issue by assuming a 'worst case scenario' for variability of pathogens, which is independent of mean pathogen levels. The model is then used to predict minimum depuration times required to achieve norovirus levels which fall within possible risk management levels, as well as predictions of minimum depuration times for other water-borne pathogens found in shellfish. Times for Escherichia coli predicted by the model all fall within the minimum 42 hours required for class B harvest sites, whereas minimum depuration times for norovirus and FRNA+ bacteriophage are substantially longer. Thus this study provides relevant information and tools to assist

  1. Epidemiology of toxic and infectious risks due to shellfish consumption; Epidemiologie des risques toxiques et infectieux lies a la consommation de coquillages

    Energy Technology Data Exchange (ETDEWEB)

    Desenclos, J C

    1996-10-01

    For feeding purposes shellfish filter large amounts of water but also concentrate infectious agents and toxins that are resent in the marine environment either naturally or because of pollution. Most of shellfish-borne infectious diseases are linked to fecal contamination of the marine environment; they include: typhoid fever, salmonellosis, shigellosis, campylobacteriosis, cholera, Norwalk or Norwalk-like gastroenteritis and hepatitis A. In warm climates, shellfish contains naturally occurring halopilic Vibrios and may cause severe sporadic infections (septicemias). Shellfish also causes outbreaks of paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP) when they are contaminated by toxins produced when Dinophisis, a marine plankton, proliferates. Chemical compounds (heavy metals and organic toxins) that are dumped in the environment (soil, air, and water) also reach shellfish harvesting waters where they are concentrated. Since it is impossible to prevent completely the contamination of coastal waters by any of the agents cited above, the prevention of shellfish-borne diseases requires monitoring of the marine environment and shellfish flesh. This surveillance allows the classification o growing areas as suitable or not for harvesting and distribution of shellfish. However, indicators of fecal pollution are particularly not reliable for shellfish viral contamination. A better knowledge of marine biology, the limitation of coastal waters pollution, improved surveillance, the development of more sensitive indicators, the responsibleness of the industry and the information of the public on the health hazards associated with shellfish consumption are the key issues for the improvement of shellfish-borne disease prevention. (author) 106 refs.

  2. Paralytic Shellfish Poisoning (PSP in Margarita Island, Venezuela

    Directory of Open Access Journals (Sweden)

    Amelia La Barbera-Sánchez

    2004-09-01

    Full Text Available A severe outbreak of Paralytic Shellfish Poisoning (PSP occurred in Manzanillo and Guayacán, northwestern coast of Margarita Island, Venezuela, between August and October 1991. A bloom of dinoflagellates including Prorocentrum gracile, Gymnodinium catenatum and Alexandrium tamarense seemed to be responsible for this outbreak. Levels of PSP toxins in mussels (Perna perna exceeded the international safety limit of saxitoxin, 80 µg STX/100 g meat. PSP toxin values varied between 2 548 and 115 µg STX/100 g meat in Manzanillo, and between 1 422 and 86 µg STX/100 g meat in Guayacán. At both locations, the highest levels were detected in August, when 24 patients exhibited typical symptoms of PSP toxicity after consuming cooked mussels (16 required hospitalization. A high pressure liquid chromatographic (HPLC procedure was recently used on the 1991 samples. The major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcSTX, but low concentrations of saxitoxin were also found in Manzanillo samples. Gonyautoxins GTX1, GTX2 and GTX3 were detected only at Guayacán, while in both locations, decarbamoylgonyatouxin (dcGTX2,3 toxins were detected. These findings represent the first time that causative toxins of PSP in Venezuela have been chemically identified, and confirm the presence of dcSTX and dcGTX in mussels from the Caribbean Sea. The presence of dcSTX and dcGTX in shellfish is indicative that Gymnodinium catenatum was a causative organism for outbreak of PSPUn severo brote de intoxicación paralizante por moluscos (PSP en inglés ocurrió en Manzanillo y Guayacán en la costa noroeste de la Isla de Margarita, Venezuela entre agosto y octubre de 1991. Una proliferación de Prorocentrum gracile, Gymnodinium catenatum y Alexandrium tamarense causó el brote. Los niveles de PSP en mejillón (Perna perna superaron los niveles máximos permisibles de saxitoxina, 80 µg STX/100g carne. Los niveles de toxinas variaron entre 2 548 y 115

  3. Forecasting the Human Pathogen Vibrio Parahaemolyticus in Shellfish Tissue within Long Island Sound

    Science.gov (United States)

    Whitney, M. M.; DeRosia-Banick, K.

    2016-02-01

    Vibrio parahaemolyticus (Vp) is a marine bacterium that occurs naturally in brackish and saltwater environments and may be found in higher concentrations in the warmest months. Vp is a growing threat to producing safe seafood. Consumption of shellfish with high Vp levels can result in gastrointestinal human illnesses. Management response to Vp-related illness outbreaks includes closure of shellfish growing areas. Water quality observations, Vp measurements, and model forecasts are key components to effective management of shellfish growing areas. There is a clear need for observations within the growing area themselves. These areas are offshore of coastal stations and typically inshore of the observing system moorings. New field observations in Long Island Sound (LIS) shellfish growing areas are described and their agreement with high-resolution satellite sea surface temperature data is discussed. A new dataset of Vp concentrations in shellfish tissue is used to determine the LIS-specific Vp vs. temperature relationship following methods in the FDA pre-harvest Vp risk model. This information is combined with output from a high-resolution hydrodynamic model of LIS to make daily forecasts of Vp levels. The influence of river inflows, the role of heat waves, and predictions for future warmer climates are discussed. The key elements of this observational-modeling approach to pathogen forecasting are extendable to other coastal systems.

  4. Monitoring emerging diseases of fish and shellfish using electronic sources.

    Science.gov (United States)

    Thrush, M A; Dunn, P L; Peeler, E J

    2012-10-01

    New and emerging fish and shellfish diseases represent an important constraint to the growth and sustainability of many aquaculture sectors and have also caused substantial economic and environmental impacts in wild stocks. This paper details the results of 8 years of a monitoring programme for emerging aquatic animal diseases reported around the world. The objectives were to track global occurrences and, more specifically, to identify and provide advanced warning of disease threats that may affect wild and farmed fish stocks in the UK. A range of electronic information sources, including Internet newsletters, alerting services and news agency releases, was systematically searched for reports of new diseases, new presentations of known pathogens and known diseases occurring in new geographic locations or new host species. A database was established to log the details of key findings, and 250 emerging disease events in 52 countries were recorded during the period of study. These included 14 new diseases and a further 16 known diseases in new species. Viruses and parasites accounted for the majority of reports (55% and 24%, respectively), and known diseases occurring in new locations were the most important emerging disease category (in which viruses were dominant). Emerging diseases were reported disproportionally in salmonid species (33%), in farmed populations (62%) and in Europe and North America (80%). The lack of reports from some regions with significant aquaculture or fishery production may indicate that emerging diseases are not being recognized in these areas owing to insufficient surveillance or testing or that these events are being under-reported. The results are discussed in relation to processes underpinning disease emergence in the aquatic environment. © 2011 Crown Copyright. Reproduced with the permission of the Controller of Her Majesty’s Stationery Office and Centre for Environment Fisheries & Aquaculture Science.

  5. Crab and shellfish occurrences in the newly-grown mangrove habitats in southern Thailand

    Science.gov (United States)

    Yeesin, P.; Bautip, S.; Chesoh, S.

    2018-04-01

    Mangrove crabs and shellfish populating in Prince of Songkla University’s new grown mangrove forest were investigated from January 2011 to December 2011 and then repeated annually. A total of 12 species under 6 families of crab and 11 species under 5 families of shellfish were recorded. The most abundant family of crab was Sesarmidae (64.18 %), followed by Ocypodidae, Varunidae, Macrophthalmidae, Portunidae and Dotillidae. Episesarma mederi ( H. Milne Edwards, 1853) showed highest dominant species. In addition, the most dominant family of shellfish was Potamididae (13.79 %), followed by Melampidae, Assimineidae, Onchidiidae and Littorinidae. Sea snail (Cerithidae quadrata; Sowerby, 1866) presented the most dominant coastal mollusc species. Abundance and diversification crabs and mollusks show important component of food web of this type ecosystem. However, only trapped hold samples during low tide were collected but this preliminary finding enables reasonable specified regulation measures.

  6. Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish.

    Science.gov (United States)

    Hood, M A; Ness, G E; Blake, N J

    1983-01-01

    The relationship of fecal coliforms, Escherichia coli, and Salmonella spp. was examined in freshly harvested and stored shellfish. In 16 of 40 freshly collected oyster samples, fecal coliform levels were above the recommended wholesale level suggested by the National Shellfish Sanitation Program (less than or equal to 230/100 g), and Salmonella spp. were present in three of these samples. Salmonella spp. were not, however, present in any sample containing less than 230 fecal coliforms per 100 g. Analysis of the data suggests that low fecal coliform levels in both fresh and stored oysters are good indicators of the absence of Salmonella spp., but that high levels of fecal coliforms are somewhat limited in predicting the presence of Salmonella spp. E. coli levels correlated very strongly with fecal coliform levels in both fresh and stored oysters and clams, suggesting that there is no advantage in replacing fecal coliforms with E. coli as an indicator of shellfish quality.

  7. Warm temperature acclimation impacts metabolism of paralytic shellfish toxins from Alexandrium minutum in commercial oysters.

    Science.gov (United States)

    Farrell, Hazel; Seebacher, Frank; O'Connor, Wayne; Zammit, Anthony; Harwood, D Tim; Murray, Shauna

    2015-09-01

    Species of Alexandrium produce potent neurotoxins termed paralytic shellfish toxins and are expanding their ranges worldwide, concurrent with increases in sea surface temperature. The metabolism of molluscs is temperature dependent, and increases in ocean temperature may influence both the abundance and distribution of Alexandrium and the dynamics of toxin uptake and depuration in shellfish. Here, we conducted a large-scale study of the effect of temperature on the uptake and depuration of paralytic shellfish toxins in three commercial oysters (Saccostrea glomerata and diploid and triploid Crassostrea gigas, n = 252 per species/ploidy level). Oysters were acclimated to two constant temperatures, reflecting current and predicted climate scenarios (22 and 27 °C), and fed a diet including the paralytic shellfish toxin-producing species Alexandrium minutum. While the oysters fed on A. minutum in similar quantities, concentrations of the toxin analogue GTX1,4 were significantly lower in warm-acclimated S. glomerata and diploid C. gigas after 12 days. Following exposure to A. minutum, toxicity of triploid C. gigas was not affected by temperature. Generally, detoxification rates were reduced in warm-acclimated oysters. The routine metabolism of the oysters was not affected by the toxins, but a significant effect was found at a cellular level in diploid C. gigas. The increasing incidences of Alexandrium blooms worldwide are a challenge for shellfish food safety regulation. Our findings indicate that rising ocean temperatures may reduce paralytic shellfish toxin accumulation in two of the three oyster types; however, they may persist for longer periods in oyster tissue. © 2015 John Wiley & Sons Ltd.

  8. Outbreak of Diarrhetic Shellfish Poisoning Associated with Mussels, British Columbia, Canada

    Science.gov (United States)

    Taylor, Marsha; McIntyre, Lorraine; Ritson, Mark; Stone, Jason; Bronson, Roni; Bitzikos, Olga; Rourke, Wade; Galanis, Eleni

    2013-01-01

    In 2011, a Diarrhetic Shellfish Poisoning (DSP) outbreak occurred in British Columbia (BC), Canada that was associated with cooked mussel consumption. This is the first reported DSP outbreak in BC. Investigation of ill individuals, traceback of product and laboratory testing for toxins were used in this investigation. Sixty-two illnesses were reported. Public health and food safety investigation identified a common food source and harvest area. Public health and regulatory agencies took actions to recall product and notify the public. Shellfish monitoring program changes were implemented after the outbreak. Improved response and understanding of toxin production will improve management of future DSP outbreaks. PMID:23697950

  9. TRPV1 as a key determinant in ciguatera and neurotoxic shellfish poisoning

    Science.gov (United States)

    Cuypers, Eva; Yanagihara, Angel; Rainier, Jon D.; Tytgat, Jan

    2007-01-01

    Ciguatera fish poisoning and neurotoxic shellfish poisoning are distinct clinical entities characterized by gastrointestinal and neurological disturbances, following the consumption of certain reef fish and shellfish containing toxic polyether compounds sporadically present in certain toxic marine dinoflagellates. The biotransformation and bioaccumulation of gambierol and brevetoxin, and their congeners, are believed to be involved in the pathogenesis of these “food-chain diseases”, for which no effective treatments are available. Here, we describe for the first time the potent effect of gambierol and brevetoxin on TRPV1 channels, a key player in thermal and pain sensation. Our findings may lead to promising new therapeutic interventions. PMID:17659256

  10. Shellfish depuration by gamma irradiation. Progress report No. 1, October 1, 1985-July 25, 1986

    International Nuclear Information System (INIS)

    Beghian, L.; Melnick, J.

    1986-01-01

    Objective is to investigate the feasibility of employing food irradiation technology to reduce or eliminate the threat of viral diseases contracted as a result of consumption of raw or inadequately cooked shellfish. Several recently published studies warn of the health risks associated with eating of raw shellfish - particularly American oysters, Crassostrea virginica, and the hardshelled clam, Mercenaria mercenaria. This study addresses the possibility of reducing the incidence of molluscanborne diseases through the application of 60 Co gamma irradiation processing to effect the inactivation of pathogenic viruses in live, raw shwllfish. Dosimetry, D 10 doses, and organoleptic effects were studied

  11. Radiation resistance of paralytic shellfish poison (PSP) toxins

    Energy Technology Data Exchange (ETDEWEB)

    San Juan, Edith M

    2000-04-01

    Radiation resistance of paralytic shellfish poison (PSP) toxins, obtained from Pyrodinium bahamense var. compressum in shellstocks of green mussels, was determined by subjecting the semi-purified toxin extract as well as the shellstocks of green mussels to high doses of ionizing radiation of 5, 10, 15 and 20 kGy. The concentration of the PSP toxins was determined by the Standard Mouse Bioassay (SMB) method. The radiation assistance of the toxins was determined by plotting the PSP toxin concentration versus applied dose in a semilog paper. The D{sub 10} value or decimal reduction dose was obtained from the straight line which is the dose required to reduce the toxicity level by 90%. The effects of irradiation on the quality of green mussels in terms of its physico-chemical, microbiological and sensory attributes were also conducted. The effect of irradiation on the fatty acid components of green mussels was determined by gas chromatography. Radiation resistance of the PSP toxins was determined to be lower in samples with initially high toxicity level as compared with samples with initially low toxicity level. The D{sub 10} values of samples with initially high PSP level were 28.5 kGy in shellstocks of green musssels and 17.5 kGy in the semi-purified toxin extract. When the PSP level was low initially, the D{sub 10} values were as high as 57.5 and 43.5 kGy in shellstocks of green mussels for the two trials, and 43.0 kGy in semi-purified toxin extract. The microbial load of the irradiated mussels was remarkably reduced. No differnce in color and odor characteristics were observed in the mussel samples subjected to varying doses of ionizing radiation. There was darkening in the color of mussel meat and its juice. The concentration of the fatty acid components in the fresh green mussels were considerably higher as compared with those present in the irradiated mussels, though some volatile fatty acids were detected as a result of irradiation. (Author)

  12. Radiation resistance of paralytic shellfish poison (PSP) toxins

    International Nuclear Information System (INIS)

    San Juan, Edith M.

    2000-04-01

    Radiation resistance of paralytic shellfish poison (PSP) toxins, obtained from Pyrodinium bahamense var. compressum in shellstocks of green mussels, was determined by subjecting the semi-purified toxin extract as well as the shellstocks of green mussels to high doses of ionizing radiation of 5, 10, 15 and 20 kGy. The concentration of the PSP toxins was determined by the Standard Mouse Bioassay (SMB) method. The radiation assistance of the toxins was determined by plotting the PSP toxin concentration versus applied dose in a semilog paper. The D 10 value or decimal reduction dose was obtained from the straight line which is the dose required to reduce the toxicity level by 90%. The effects of irradiation on the quality of green mussels in terms of its physico-chemical, microbiological and sensory attributes were also conducted. The effect of irradiation on the fatty acid components of green mussels was determined by gas chromatography. Radiation resistance of the PSP toxins was determined to be lower in samples with initially high toxicity level as compared with samples with initially low toxicity level. The D 10 values of samples with initially high PSP level were 28.5 kGy in shellstocks of green musssels and 17.5 kGy in the semi-purified toxin extract. When the PSP level was low initially, the D 10 values were as high as 57.5 and 43.5 kGy in shellstocks of green mussels for the two trials, and 43.0 kGy in semi-purified toxin extract. The microbial load of the irradiated mussels was remarkably reduced. No differnce in color and odor characteristics were observed in the mussel samples subjected to varying doses of ionizing radiation. There was darkening in the color of mussel meat and its juice. The concentration of the fatty acid components in the fresh green mussels were considerably higher as compared with those present in the irradiated mussels, though some volatile fatty acids were detected as a result of irradiation. (Author)

  13. Spatiotemporal patterns of paralytic shellfish toxins and their relationships with environmental variables in British Columbia, Canada from 2002 to 2012.

    Science.gov (United States)

    Finnis, Stephen; Krstic, Nikolas; McIntyre, Lorraine; Nelson, Trisalyn A; Henderson, Sarah B

    2017-07-01

    Harmful algal blooms produce paralytic shellfish toxins that accumulate in the tissues of filter feeding shellfish. Ingestion of these toxic shellfish can cause a serious and potentially fatal condition known as paralytic shellfish poisoning (PSP). The coast of British Columbia is routinely monitored for shellfish toxicity, and this study uses data from the monitoring program to identify spatiotemporal patterns in shellfish toxicity events and their relationships with environmental variables. The dinoflagellate genus Alexandrium produces the most potent paralytic shellfish toxin, saxitoxin (STX). Data on all STX measurements were obtained from 49 different shellfish monitoring sites along the coast of British Columbia for 2002-2012, and monthly toxicity events were identified. We performed hierarchical cluster analysis to group sites that had events in similar areas with similar timing. Machine learning techniques were used to model the complex relationships between toxicity events and environmental variables in each group. The Strait of Georgia and the west coast of Vancouver Island had unique toxicity regimes. Out of the seven environmental variables used, toxicity in each cluster could be described by multivariable models including monthly sea surface temperature, air temperature, sea surface salinity, freshwater discharge, upwelling, and photosynthetically active radiation. The sea surface salinity and freshwater discharge variables produced the strongest univariate models for both geographic areas. Applying these methods in coastal regions could allow for the prediction of shellfish toxicity events by environmental conditions. This has the potential to optimize biotoxin monitoring, improve public health surveillance, and engage the shellfish industry in helping to reduce the risk of PSP. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Fate of benzoate paralytic shellfish poisoning toxins from Gymnodinium catenatum in shellfish and fish detected by pre-column oxidation and liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Vale, Paulo

    2008-05-09

    Several cultured strains of Gymnodinium catenatum isolated worldwide have been shown to produce important proportions of the recently discovered benzoate paralytic shellfish poisoning (PSP) toxins GC1 through GC3. These toxins pose a new challenge for the HPLC analysis of shellfish predating during blooms of this microalga because due to their hydrophobicity are retained along the C18 solid-phase extraction step employed to eliminate interferences. The production of GC toxins was confirmed in a clone of G.catenatum isolated from the Portuguese Northwest coast during the winter bloom of 2005, in addition to a clone from 1989 reported previously by other authors. The major peroxide oxidation products of GC1+2 and GC3 were, respectively, dcGTX2+3 and dcSTX. The search of benzoate analogues in bivalves contaminated during the winter 2005 bloom showed these analogues constituted a minor component of the N(1)-H containing toxins, as selectively detected by peroxide oxidation. While in G.catenatum GC1-3 were the major components after C1+2 and B1, in bivalves dcGTX2+3 and dcSTX were the major components after C1+2 and B1. Similar conclusions were later extended to more shellfish species naturally contaminated during the autumn bloom of 2007. In the gut content of sardines GC toxins were present, while in crabs predating upon shellfish, these were absent. A generalised conversion of GC toxins into decarbamoyl analogues was confirmed by in vitro incubations of bivalve's digestive glands with semi-purified GC toxins. This is the first report of widespread carbamoylase activity in shellfish, exclusively targeted at benzoate PSP analogues and that is heat-inactivated. Despite the high proportion of benzoate analogues produced by G.catenatum, analyses of bivalves contaminated with PSP toxins seem to be simplified due to the important conversion of benzoate into decarbamoyl analogues that occurs in bivalves. These last analogues are detected by common HPLC methods used for food

  15. The first closure of shellfish harvesting due to domoic acid in Puget ...

    African Journals Online (AJOL)

    Since the early 1990s, blooms containing multiple. Pseudo-nitzschia species have been observed in Puget Sound and low levels of DA have been detected in shellfish, but highly toxic, nearly monospecific blooms had not been observed. We speculate that a more toxic 'oceanic' strain may recently have been advected from ...

  16. The use of electron spin resonance spectroscopy for the detection of irradiated shellfish and spices

    International Nuclear Information System (INIS)

    Helle, N.; Linke, B.; Boegl, K.W.; Schreiber, G.A.

    1994-01-01

    A multilateral study on common shrimps, Norway lobster and paprika powder. The use of ESR spectroscopy in shellfish and some types of spice for the detection of previous irradiation is possible even on a routine basis. The radicals producing the specific ESR signals observed could at least in part be identified (CO 2 radicals in shellfish, cellulose radicals in paprica) and the overall rate of correct classifications was seen to be very high for this multicentre study. The multicentre study has further been able to prove that previous reservations about ESR as a method of detection are no longer justified. The authors hold that there is no reason in principle why ESR should not be on the list of officially recommended methods for the examination of shellfish and spices according to paragraph35 LMBG. Nevertheless, the two groups of food at issue here need to be investigated in more detail in a number of further research projects, some of which are mentioned in the following: -investigations on further species of shellfish so as to obtain a broad range of spectra for routine controls; - structural identification of radiation-specific radicals generated in addition to the CO 2 radical; - investigations into the influences of origin, time of fishing and stage of development on the ESR spectra of fishes; - examinations of further spices; - elucidation of links between cellulose contents and radical concentration. (orig./vhe) [de

  17. 77 FR 36260 - Proposed Information Collection; Comment Request; Puget Sound Recreational Shellfish Harvesting...

    Science.gov (United States)

    2012-06-18

    ... Collection; Comment Request; Puget Sound Recreational Shellfish Harvesting Project AGENCY: National Oceanic..., as required by the Paperwork Reduction Act of 1995. DATES: Written comments must be submitted on or... for a new collection of information. The Puget Sound estuary provides one of the most valuable...

  18. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Science.gov (United States)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  19. 76 FR 37815 - Cooperative Agreement To Support Shellfish Safety Assistance Project

    Science.gov (United States)

    2011-06-28

    .... vulnificus control plan; 11. In conjunction with FDA, conduct of retail and processing plant product sampling... levels of Vibrios; and; 12. In conjunction with FDA, conduct of a retail shellfish study to look at the...; funding support to research the influence of water and air temperature, dissolved oxygen, and nutrients on...

  20. Biodiversity and food web indicators of community recovery in intertidal shellfish reefs

    NARCIS (Netherlands)

    Christianen, M.J.A.; Heide, van der T.; Holthuijsen, S.J.; Reijden, van der K.J.; Borst, A.C.W.; Olff, H.

    2017-01-01

    In conservation strategies of marine ecosystems, priority is given to habitat-structuring foundation species (e.g. seagrasses, mangroves and reef-building corals, shellfish) with the implicit goal to protect or restore associated communities and their interactions. However, the number and accuracy

  1. Biodiversity and food web indicators of community recovery in intertidal shellfish reefs

    NARCIS (Netherlands)

    Christianen, M.J.A.; van der Heide, T.; Holthuijsen, S.J.; van der Reijden, K.J.; Borst, A.C.W.; Olff, H.

    2017-01-01

    In conservation strategies of marine ecosystems, priority is given to habitat-structuring foundation species (e.g.seagrasses, mangroves and reef-building corals, shellfish) with the implicit goal to protect or restore associatedcommunities and their interactions. However, the number and accuracy of

  2. Biodiversity and food web indicators of community recovery in intertidal shellfish reefs

    NARCIS (Netherlands)

    Christianen, M.J.A.; van der Heide, T.; Holthuijsen, S.J.; van der Reijden, K.J.; Borst, A.C.W.; Olff, H.

    In conservation strategies of marine ecosystems, priority is given to habitat-structuring foundation species (e.g. seagrasses, mangroves and reef-building corals, shellfish) with the implicit goal to protect or restore associated communities and their interactions. However, the number and accuracy

  3. Detection of hepatitis A virus in shellfish by nested reverse transcription-PCR

    NARCIS (Netherlands)

    Croci, L.; Medici, de D.; Morace, G.; Fiore, A.; Scalfaro, C.; Beneduce, F.; Toti, L.

    1999-01-01

    A method for the detection of HAV in shellfish, based on the use of guanidinium isothiocyanate-contg. soln. for RNA extn. and purifn. steps, followed by nested PCR, is hereby proposed. Tests were carried out on mollusc samples spiked with HAV strain FG. Results showed that in samples subjected only

  4. Communicating Environmental Risks: Local Newspaper Coverage of Shellfish Bacterial Contamination in Maine

    Directory of Open Access Journals (Sweden)

    Brianne Suldovsky

    2018-03-01

    Full Text Available Coastal resources play a vital role in Maine’s cultural and economic wellbeing, contributing an estimated 168 billion dollars to the Maine economy. There are numerous risks to the sustainability of Maine’s shellfishing industry and working waterfront, including pathogenic bacterial pollution. In this study, we ask a broad fundamental question central to science and environmental journalism: how do newspapers cover localized environmental risks and what are the implications of those approaches? Utilizing the northeastern US state of Maine’s shellfishing industry as an exemplar environmental issue, this study examines how Maine’s two most read newspapers, the Bangor Daily News and the Portland Press Herald, report on bacterial contamination and shellfish. This study examines the themes that are present in the newspaper articles published about shellfish between 2003 and 2014 and analyses the types of sources journalists used within their coverage of these issues. Overall, we identified seven key themes: economic concerns, environmental impacts, political and regulatory issues, issues of public health and safety, reference to cultural values, technical and infrastructural issues, and aesthetic concerns. The most commonly cited individuals in the articles were government officials and scientists. The least cited groups were clammers and shellfishermen, general citizens, advocacy groups, and worm diggers. Implications for local coverage of environmental risks in Maine, science communication, and sustainability science are discussed.

  5. Stable isotope database - Transport and fate of nutrient and pathogen loadings into nearshore Puget Sound: consequences for shellfish growing areas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project seeks to develop and apply an assessment of shellfish growing area (SGA) vulnerability to closures caused by watershed- and marine-derived pathogens....

  6. NODC Standard Format Marine Fish and Shellfish Surveys (F123) Data (1948-1992) (NODC Accession 0014195)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data type contains data from field sampling of marine fish and shellfish. The data derive from analyses of midwater or bottom tow catches and provide...

  7. Oil spill off the coast of Guimaras Island, Philippines: Distributions and changes of polycyclic aromatic hydrocarbons in shellfish.

    Science.gov (United States)

    Uno, Seiichi; Kokushi, Emiko; Añasco, Nathaniel C; Iwai, Takenori; Ito, Kazuki; Koyama, Jiro

    2017-11-30

    The sinking of the Solar 1 tanker caused serious heavy oil pollution around Guimaras Island, Philippines. In the present study, variations of parent polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs (alkPAHs) in some shellfish were investigated around Guimaras Island and other small islands from 3months to 5years after the spill. The total PAHs and alkPAHs in shellfish were detected in high concentrations at 448 and 33,666ng/g dry weight, respectively, in November 2006. The concentrations of alkPAHs gradually decreased, while the parent PAHs in shellfish degraded more slowly than the alkPAHs, which was likely due to the persistent characteristics of PAHs. The risks based on European Union regulations were insignificant in 2008, but total PAHs in shellfish were still over 8 times higher at the investigated sites in November 2011 than that before the oil spill. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Critical Review on the Public Health Impact of Norovirus Contamination in Shellfish and the Environment: A UK Perspective.

    Science.gov (United States)

    Hassard, Francis; Sharp, Jasmine H; Taft, Helen; LeVay, Lewis; Harris, John P; McDonald, James E; Tuson, Karen; Wilson, James; Jones, David L; Malham, Shelagh K

    2017-06-01

    We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3-11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards.

  9. Effects of marine wind farms on the distribution of fish, shellfish and marine mammals in the Horns Rev area

    International Nuclear Information System (INIS)

    Hoffmann, E.; Astrup, J.; Larsen, Finn; Munch-Petersen, S.

    2000-01-01

    The purpose of the report is: 1) to give a quantitative description of the abundance of the fish and shellfish in the area surrounding the windmill area and to evaluate the effects of the physically presence of the windmills on the abundance of fish and shellfish in the area; 2) to evaluate the artificial reef effect in the windmill area; 3) to evaluate the effects of noise and electromagnetic fields on the abundance of fish and marine mammals. (au)

  10. Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

    OpenAIRE

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-01-01

    The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were sign...

  11. Effects of marine wind farms on the distribution of fish, shellfish and marine mammals in the Horns Rev area

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, E; Astrup, J; Larsen, Finn; Munch-Petersen, S

    2000-05-15

    The purpose of the report is: 1) to give a quantitative description of the abundance of the fish and shellfish in the area surrounding the windmill area and to evaluate the effects of the physically presence of the windmills on the abundance of fish and shellfish in the area; 2) to evaluate the artificial reef effect in the windmill area; 3) to evaluate the effects of noise and electromagnetic fields on the abundance of fish and marine mammals. (au)

  12. Paralytic shellfish poison algal biotoxins: Sardinia report 2002-2011 and non-compliance management

    Directory of Open Access Journals (Sweden)

    Giuseppa Lorenzoni

    2013-09-01

    Full Text Available Several microalgae of the genus Alexandrium (Alexandrium minutum and Alexandrium catenelle can produce an algal biotoxin, the paralytic shellfish poison (PSP that can be accumulated in the shellfish edible tissues making them hazardous to the consumer’s health. In this paper we report i the results of PSP toxins survey carried out by mouse bioassays (mouse test AOAC 958.08 on 7457 samples of bivalve molluscs farmed in Sardinia and in other European countries and marketed in Sardinia region from 2002 to 2011, and ii the management of positive cases. Based on our experience it is very important to strictly apply the planned activities in order to prevent any risk and to protect the consumer’s and producer’s health.

  13. Fatal paralytic shellfish poisoning in Kittlitz's Murrelet (Brachyramphus brevirostris) nestlings, Alaska, USA

    Science.gov (United States)

    Shearn-Bochsler, Valerie I.; Lance, Ellen W.; Corcoran, Robin; Piatt, John F.; Bodenstein, Barbara; Frame, Elizabeth; Lawonn, James

    2014-01-01

    Paralytic shellfish poisoning (PSP) is an acute toxic illness in humans resulting from ingestion of shellfish contaminated with a suite of neurotoxins (saxitoxins) produced by marine dinoflagellates, most commonly in the genus Alexandrium. Poisoning also has been sporadically suspected and, less often, documented in marine wildlife, often in association with an outbreak in humans. Kittlitz's Murrelet (Brachyramphus brevirostris) is a small, rare seabird of the Northern Pacific with a declining population. From 2008 to 2012, as part of a breeding ecology study, multiple Kittlitz's Murrelet nests on Kodiak Island, Alaska, were monitored by remote cameras. During the 2011 and 2012 breeding seasons, nestlings from several sites died during mild weather conditions. Remote camera observations revealed that the nestlings died shortly after consuming sand lance (Ammodytes hexapterus), a fish species known to biomagnify saxitoxin. High levels of saxitoxin were subsequently documented in crop content in 87% of nestling carcasses. Marine bird deaths from PSP may be underreported.

  14. Diarrhetic shellfish poisoning toxin esters in Danish blue mussels and surf clams

    DEFF Research Database (Denmark)

    Jørgensen, Kevin; Scanlon, Sine Hedegaard; Jensen, L.B.

    2005-01-01

    Until recently, little focus was given to the presence of diarrhetic shellfish poisoning ( DSP) toxin esters in seafood products. However, during the last few years, the occurrence of a high percentage of esters of the total amount of DSP toxins present in some seafood products has been observed....... importance because of the increased use of chemical methods instead of mouse bioassay for the detection of DSP toxicity....

  15. Modeling of Faecal Contamination in Water from Catchment to Shellfish Growing Area

    OpenAIRE

    Bougeard, Morgane; Le Saux, Jean-claude; Perenne, Nicolas; Le Guyader, Soizick; Pommepuy, Monique

    2009-01-01

    During rainstorms, watersheds can introduce large amounts of faecal pollution into the rivers and sea, leading to shellfish contamination. In this study, we assessed Escherichia coli fluxes from a catchment, and their impact on estuarine water quality, using two assembled models. For the catchment, the agro-hydrological model SWAT was implemented integrating land uses, soil, topography, rainfall and other climatic data on Daoulas watershed (France). Initially, the SWAT model was calibrated an...

  16. Evidence for paralytic shellfish poisons in the freshwater cyanobacterium Lyngbya wollei (Farlow ex Gomont) comb. nov.

    OpenAIRE

    Carmichael, W W; Evans, W R; Yin, Q Q; Bell, P; Moczydlowski, E

    1997-01-01

    Lyngbya wollei (Farlow ex Gomont) comb. nov., a perennial mat-forming filamentous cyanobacterium prevalent in lakes and reservoirs of the southeastern United States, was found to produce a potent, acutely lethal neurotoxin when tested in the mouse bioassay. Signs of poisoning were similar to those of paralytic shellfish poisoning. As part of the Tennessee Valley Authority master plan for Guntersville Reservoir, the mat-forming filamentous cyanobacterium L. wollei, a species that had recently ...

  17. Microplastics in the context of regulation of commercial shellfish aquaculture operations.

    Science.gov (United States)

    Schoof, Rosalind A; DeNike, Jesse

    2017-05-01

    Shellfish aquaculture in the Salish Sea (encompassing the Strait of Juan de Fuca, Puget Sound, and the Georgia Strait) is a major source of clams, oysters, and mussels in the United States and Canada. Plastic gear is necessary for the viability of many of these operations. During the past few years, shellfish farm permits issued in Washington State have been challenged on various bases that have included allegations that the plastic gear is releasing microplastics, commonly defined as particles less than 5 mm in diameter. Published survey data on sources of marine plastic debris demonstrate the very limited contribution of aquaculture gear. Both permits and industry codes of practice provide procedures to minimize loss of gear to the marine environment. Plastic gear is also designed specifically to maintain its integrity and not degrade in the marine environment. Plastic degradation is greatest on beaches with high UV exposure, whereas aquaculture gear is mostly underwater and/or covered by biofoulants. Available data for microplastics in water, sediment, and biota of the Salish Sea do not suggest significant release of microplastics from shellfish aquaculture operations. Integr Environ Assess Manag 2017;13:522-527. © 2017 SETAC. © 2017 SETAC.

  18. Spoilage and shelf-life extension of fresh fish and shellfish.

    Science.gov (United States)

    Ashie, I N; Smith, J P; Simpson, B K

    1996-01-01

    Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish-processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low-dose irradiation, ultra-high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.

  19. Time-series prediction of shellfish farm closure: A comparison of alternatives

    Directory of Open Access Journals (Sweden)

    Ashfaqur Rahman

    2014-08-01

    Full Text Available Shellfish farms are closed for harvest when microbial pollutants are present. Such pollutants are typically present in rainfall runoff from various land uses in catchments. Experts currently use a number of observable parameters (river flow, rainfall, salinity as proxies to determine when to close farms. We have proposed using the short term historical rainfall data as a time-series prediction problem where we aim to predict the closure of shellfish farms based only on rainfall. Time-series event prediction consists of two steps: (i feature extraction, and (ii prediction. A number of data mining challenges exist for these scenarios: (i which feature extraction method best captures the rainfall pattern over successive days that leads to opening or closure of the farms?, (ii The farm closure events occur infrequently and this leads to a class imbalance problem; the question is what is the best way to deal with this problem? In this paper we have analysed and compared different combinations of balancing methods (under-sampling and over-sampling, feature extraction methods (cluster profile, curve fitting, Fourier Transform, Piecewise Aggregate Approximation, and Wavelet Transform and learning algorithms (neural network, support vector machine, k-nearest neighbour, decision tree, and Bayesian Network to predict closure events accurately considering the above data mining challenges. We have identified the best combination of techniques to accurately predict shellfish farm closure from rainfall, given the above data mining challenges.

  20. Review of availability of food composition data for fish and shellfish.

    Science.gov (United States)

    Rittenschober, Doris; Nowak, Verena; Charrondiere, U Ruth

    2013-12-15

    The FAO/INFOODS database on fish and shellfish (aFiSh) is a collection of analytical data from primary sources and holds values for 2,277 entries on raw and processed food with sufficient quality. Most data were entered on fatty acids (60%), followed by macronutrients and their fractions (16%), minerals (10%), amino acids (7%), (pro)vitamins (2%), heavy metals (2%) and other components (3%). Information on several factors that contribute to the variation of compositional data (e.g., biodiversity, catch season, habitat, size and part of fish/shellfish analysed) as well as the bibliographic references are presented alongside with each food entry. The data were published in the FAO/INFOODS Food Composition Database for Biodiversity (BioFoodComp2.0) and in the FAO/INFOODS Analytical Food Composition Database (AnFooD1.0), freely available at the INFOODS webpage http://www.fao.org/infoods/biodiversity/index_en.stm. The provision of easy accessible, analytical compositional data should be seen as stimulation for researchers and compilers to incorporate more analytical and detailed data of fish and shellfish into future food composition tables and databases and to improve dietary assessment tools. Copyright © 2013 Food and Agriculture Organization of the United Nations. Published by Elsevier Ltd.. All rights reserved.

  1. Evaluation of Rapid, Early Warning Approaches to Track Shellfish Toxins Associated with Dinophysis and Alexandrium Blooms

    Directory of Open Access Journals (Sweden)

    Theresa K. Hattenrath-Lehmann

    2018-01-01

    Full Text Available Marine biotoxin-contaminated seafood has caused thousands of poisonings worldwide this century. Given these threats, there is an increasing need for improved technologies that can be easily integrated into coastal monitoring programs. This study evaluates approaches for monitoring toxins associated with recurrent toxin-producing Alexandrium and Dinophysis blooms on Long Island, NY, USA, which cause paralytic and diarrhetic shellfish poisoning (PSP and DSP, respectively. Within contrasting locations, the dynamics of pelagic Alexandrium and Dinophysis cell densities, toxins in plankton, and toxins in deployed blue mussels (Mytilus edulis were compared with passive solid-phase adsorption toxin tracking (SPATT samplers filled with two types of resin, HP20 and XAD-2. Multiple species of wild shellfish were also collected during Dinophysis blooms and used to compare toxin content using two different extraction techniques (single dispersive and double exhaustive and two different toxin analysis assays (liquid chromatography/mass spectrometry and the protein phosphatase inhibition assay (PP2A for the measurement of DSP toxins. DSP toxins measured in the HP20 resin were significantly correlated (R2 = 0.7–0.9, p < 0.001 with total DSP toxins in shellfish, but were detected more than three weeks prior to detection in deployed mussels. Both resins adsorbed measurable levels of PSP toxins, but neither quantitatively tracked Alexandrium cell densities, toxicity in plankton or toxins in shellfish. DSP extraction and toxin analysis methods did not differ significantly (p > 0.05, were highly correlated (R2 = 0.98–0.99; p < 0.001 and provided complete recovery of DSP toxins from standard reference materials. Blue mussels (Mytilus edulis and ribbed mussels (Geukensia demissa were found to accumulate DSP toxins above federal and international standards (160 ng g−1 during Dinophysis blooms while Eastern oysters (Crassostrea virginica and soft shell clams (Mya

  2. On the Frontline: Tracking Ocean Acidification in an Alaskan Shellfish Hatchery

    Science.gov (United States)

    Evans, Wiley; Mathis, Jeremy T.; Ramsay, Jacqueline; Hetrick, Jeff

    2015-01-01

    The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonate system such that saturation states of calcium carbonate (CaCO3) minerals are decreasing, and this is having a detrimental impact on early life stages of select shellfish species. The global, secular decrease in CaCO3 saturation states is occurring on top of a backdrop of large natural variability in coastal settings; progressively shifting the envelope of variability and leading to longer and more frequent exposure to adverse conditions. This is a great concern in the State of Alaska, a high-latitude setting vulnerable to rapid changes in the marine carbonate system, where an emerging shellfish industry plans major growth over the coming decades. Currently, the Alutiiq Pride Shellfish Hatchery (APSH) in Seward, Alaska is the only hatchery in the state, and produces many shellfish species with early life stages known to be sensitive to low CaCO3 saturation states. Here we present the first land-based OA measurements made in an Alaskan shellfish hatchery, and detail the trends in the saturation state of aragonite (Ωarag), the more soluble form of CaCO3, over a 10-month period in the APSH seawater supply. These data indicate the largest changes are on the seasonal time scale, with extended periods of sub-optimal Ωarag levels (Ωarag < 1.5) in winter and autumn associated with elevated water column respiration and short-lived runoff events, respectively. The data pinpoint a 5-month window of reprieve with favorable Ωarag conditions above the sub-optimal Ωarag threshold, which under predicted upper-bound CO2 emissions trajectories is estimated to close by 2040. To date, many species in production at APSH remain untested in their response to OA, and the data presented here establish the current conditions at APSH as well as provide a framework for hatchery-based measurements in Alaska. The current and expected conditions seen at APSH are essential to consider for this

  3. Evaluation of different conditions and culture media for the recovery of Aeromonas spp. from water and shellfish samples.

    Science.gov (United States)

    Latif-Eugenín, F; Beaz-Hidalgo, R; Figueras, M J

    2016-09-01

    To perform a comparative study for determining the optimum culture method (direct plating or enrichment) and medium (ampicillin dextrin agar (ADA), starch ampicillin agar (SAA), bile salts irgasan brilliant green modified (BIBG-m)) for recovering Aeromonas species from water and shellfish samples. By direct culture, Aeromonas was detected in 65% (13/20) of the water samples and in 54·5% (6/11) of the shellfish samples. However, when a pre-enrichment step was included, the number of positive water samples increased to 75% (15/20) and the ones of shellfish to 90·1% (10/11). The enriched culture significantly favoured (P culture medium for detecting Aeromonas from water was ADA. However, no differences were observed in the case of shellfish samples (P > 0·05). Isolation of Aeromonas media from water was favoured (P culture method and medium used influenced the recovery of some Aeromonas species from water and shellfish samples. This fact should be considered in future prevalence studies to avoid overestimating the above mentioned Aeromonas species. © 2016 The Society for Applied Microbiology.

  4. Beneficial of Coriander Leaves (Coriandrum sativum L.) to Reduce Heavy Metals Contamination in Rod Shellfish

    Science.gov (United States)

    Winarti, S.; Pertiwi, C. N.; Hanani, A. Z.; Mujamil, S. I.; Putra, K. A.; Herlambang, K. C.

    2018-01-01

    Contamination of heavy metals in certain levels of food can disrupt human health. Heavy metals have toxic properties, cannot be overhauled or destroyed by living organisms, can accumulate in the body of organisms including humans, either directly or indirectly. Heavy metal Hg, Cd, Cr is a very toxic metals (can result in death or health problems that are not recovered in a short time), while heavy metal Co, Pb, Cu toxicity is moderate (can lead to both recoverable and non-recoverable health problems in a relatively long time). Hence the heavy metal contaminating the food must be eliminated or reduced to a safe level. One effort was use coriander leaves to reduce the contamination of heavy metals in fish/shellfish. The objective of the research was to prove the extract of coriander leaves can reduce heavy metal contamination of Pb, Hg and Cu in rod shellfish (lorjuk). The treatment of this research was long soaking in coriander leaves extract that were 0, 30, 60 and 90 minutes. The results showed that the longer time of soaking can decrease Pb level from 4.4 ± 0.424 ppb to 1.7 ± 0.5 ppb, Hg level from 4.11± 0.07 to 1.12± 0.6 ppb, and Cu level from 433.7 ± 0.1 ppb to 117 ± 0.78 ppb. Protein content not significant decrease in rod shellfish (lorjuk) after 90 minutes soaking time, that was from 28.56 ± 0.403% to 26,625 ± 0.19%.

  5. Uptake, transfer and elimination kinetics of paralytic shellfish toxins in common octopus (Octopus vulgaris).

    Science.gov (United States)

    Lopes, Vanessa M; Baptista, Miguel; Repolho, Tiago; Rosa, Rui; Costa, Pedro Reis

    2014-01-01

    Marine phycotoxins derived from harmful algal blooms are known to be associated with mass mortalities in the higher trophic levels of marine food webs. Bivalve mollusks and planktivorous fish are the most studied vectors of marine phycotoxins. However, field surveys recently showed that cephalopod mollusks also constitute potential vectors of toxins. Thus, here we determine, for the first time, the time course of accumulation and depuration of paralytic shellfish toxins (PSTs) in the common octopus (Octopus vulgaris). Concomitantly, the underlying kinetics of toxin transfer between tissue compartments was also calculated. Naturally contaminated clams were used to orally expose the octopus to PSTs during 6 days. Afterwards, octopus specimens were fed with non-contaminated shellfish during 10 days of depuration period. Toxins reached the highest concentrations in the digestive gland surpassing the levels in the kidney by three orders of magnitude. PSTs were not detected in any other tissue analyzed. Net accumulation efficiencies of 42% for GTX5, 36% for dcSTX and 23% for C1+2 were calculated for the digestive gland. These compounds were the most abundant toxins in both digestive gland and the contaminated shellfish diet. The small differences in relative abundance of each toxin observed between the prey and the cephalopod predator indicates low conversion rates of these toxins. The depuration period was better described using an exponential decay model comprising a single compartment - the entire viscera. It is worth noting that since octopuses' excretion and depuration rates are low, the digestive gland is able to accumulate very high toxin concentrations for long periods of time. Therefore, the present study clearly shows that O. vulgaris is a high-potential vector of PSTs during and even after the occurrence of these toxic algal blooms. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Canning process that diminishes paralytic shellfish poison in naturally contaminated mussels (Mytilus galloprovincialis).

    Science.gov (United States)

    Vieites, J M; Botana, L M; Vieytes, M R; Leira, F J

    1999-05-01

    Changes in toxin profile and total toxicity levels of paralytic shellfish poison (PSP)-containing mussels were monitored during the standard canning process of pickled mussels and mussels in brine using mouse bioassays and high-performance liquid chromatography. Detoxification percentages for canned mussel meat exceeded 50% of initial toxicity. Total toxicity reduction did not fully correspond to toxin destruction, which was due to the loss of PSP to cooking water and packing media of the canned product. Significant differences in detoxification percentages were due to changes in toxin profile during heat treatment in packing media. Toxin conversion phenomena should be determined to validate detoxification procedures in the canning industry.

  7. Sterol composition of shellfish species commonly consumed in the United States

    Directory of Open Access Journals (Sweden)

    Katherine M. Phillips

    2012-10-01

    Full Text Available Background: Shellfish can be a component of a healthy diet due to a low fat and high protein content, but the cholesterol content of some species is often cited as a reason to limit their consumption. Data on levels of non-cholesterol sterols in commonly consumed species are lacking. Objective: Shellfish were sampled and analyzed to update sterol data in the United States Department of Agriculture (USDA National Nutrient Database for Standard Reference. Design: Using a nationwide sampling plan, raw shrimp and sea scallops, canned clams, and steamed oysters, blue crab, and lobster were sampled from 12 statistically selected supermarkets across the United States in 2007-08. For each species, four composites were analyzed, each comprised of samples from three locations; shrimp and scallops from six single locations were also analyzed separately. Using validated analytical methodology, 14 sterols were determined in total lipid extracts after saponification and derivatization to trimethylsilyethers, using gas chromatography for quantitation and mass spectrometry for confirmation of components. Results: Crab, lobster, and shrimp contained significant cholesterol (96.2–27 mg/100 g; scallops and clams had the lowest concentrations (23.4–30.1 mg/100 g. Variability in cholesterol among single-location samples of shrimp was low. The major sterols in the mollusks were brassicasterol (12.6–45.6 mg/100 g and 24-methylenecholesterol (16.7–41.9 mg/100 g, with the highest concentrations in oysters. Total non-cholesterol sterols were 46.5–75.6 mg/100 g in five single-location scallops samples, but 107 mg/100 g in the sixth, with cholesterol also higher in that sample. Other prominent non-cholesterol sterols in mollusks were 22-dehydrocholesterol, isofucosterol, clionasterol, campesterol, and 24-norcholesta-5,22-diene-3β-ol (4–21 mg/100 g. Conclusions: The presence of a wide range of sterols, including isomeric forms, in shellfish makes the analysis

  8. Paralytic shellfish toxin biosynthesis in cyanobacteria and dinoflagellates: A molecular overview.

    Science.gov (United States)

    Wang, Da-Zhi; Zhang, Shu-Fei; Zhang, Yong; Lin, Lin

    2016-03-01

    Paralytic shellfish toxins (PSTs) are a group of water soluble neurotoxic alkaloids produced by two different kingdoms of life, prokaryotic cyanobacteria and eukaryotic dinoflagellates. Owing to the wide distribution of these organisms, these toxic secondary metabolites account for paralytic shellfish poisonings around the world. On the other hand, their specific binding to voltage-gated sodium channels makes these toxins potentially useful in pharmacological and toxicological applications. Much effort has been devoted to the biosynthetic mechanism of PSTs, and gene clusters encoding 26 proteins involved in PST biosynthesis have been unveiled in several cyanobacterial species. Functional analysis of toxin genes indicates that PST biosynthesis in cyanobacteria is a complex process including biosynthesis, regulation, modification and export. However, less is known about the toxin biosynthesis in dinoflagellates owing to our poor understanding of the massive genome and unique chromosomal characteristics [1]. So far, few genes involved in PST biosynthesis have been identified from dinoflagellates. Moreover, the proteins involved in PST production are far from being totally explored. Thus, the origin and evolution of PST biosynthesis in these two kingdoms are still controversial. In this review, we summarize the recent progress on the characterization of genes and proteins involved in PST biosynthesis in cyanobacteria and dinoflagellates, and discuss the standing evolutionary hypotheses concerning the origin of toxin biosynthesis as well as future perspectives in PST biosynthesis. Paralytic shellfish toxins (PSTs) are a group of potent neurotoxins which specifically block voltage-gated sodium channels in excitable cells and result in paralytic shellfish poisonings (PSPs) around the world. Two different kingdoms of life, cyanobacteria and dinoflagellates are able to produce PSTs. However, in contrast with cyanobacteria, our understanding of PST biosynthesis in

  9. Evidence for paralytic shellfish poisons in the freshwater cyanobacterium Lyngbya wollei (Farlow ex Gomont) comb. nov.

    Science.gov (United States)

    Carmichael, W W; Evans, W R; Yin, Q Q; Bell, P; Moczydlowski, E

    1997-08-01

    Lyngbya wollei (Farlow ex Gomont) comb. nov., a perennial mat-forming filamentous cyanobacterium prevalent in lakes and reservoirs of the southeastern United States, was found to produce a potent, acutely lethal neurotoxin when tested in the mouse bioassay. Signs of poisoning were similar to those of paralytic shellfish poisoning. As part of the Tennessee Valley Authority master plan for Guntersville Reservoir, the mat-forming filamentous cyanobacterium L. wollei, a species that had recently invaded from other areas of the southern United States, was studied to determine if it could produce any of the known cyanotoxins. Of the 91 field samples collected at 10 locations at Guntersville Reservoir, Ala., on the Tennessee River, over a 3-year period, 72.5% were toxic. The minimum 100% lethal doses of the toxic samples ranged from 150 to 1,500 mg kg of lyophilized L. wollei cells-1, with the majority of samples being toxic at 500 mg kg-1. Samples bioassayed for paralytic shellfish toxins by the Association of Official Analytical Chemists method exhibited saxitoxin equivalents ranging from 0 to 58 micrograms g (dry weight)-1. Characteristics of the neurotoxic compound(s), such as the lack of adsorption by C18 solid-phase extraction columns, the short retention times on C18 high-performance liquid chromatography (HPLC) columns, the interaction of the neurotoxins with saxiphilin (a soluble saxitoxin-binding protein), and external blockage of voltage-sensitive sodium channels, led to our discovery that this neurotoxin(s) is related to the saxitoxins, the compounds responsible for paralytic shellfish poisonings. The major saxitoxin compounds thus far identified by comparison of HPLC fluorescence retention times are decarbamoyl gonyautoxins 2 and 3. There was no evidence of paralytic shellfish poison C toxins being produced by L. wollei. Fifty field samples were placed in unialgal culture and grown under defined culture conditions. Toxicity and signs of poisoning for these

  10. Variation of 137Cs and 239,240Pu concentrations in shellfishes on the coast of Ibaraki prefecture

    International Nuclear Information System (INIS)

    Fujita, Hiroki; Nakano, Masanao

    2007-01-01

    The concentrations of 137 Cs and 239,240 Pu in shellfishes collected from the coast around the Tokai Reprocessing Plant (TRP) from 1975 to 2005 were analyzed for environmental radiological monitoring. The measured concentrations of 238 Pu were under the detection limits and these concentrations of 137 Cs and 239,240 Pu showed no significant short-term increase tendency. It was confirmed that 137 Cs and 239,240 Pu in shellfishes around the TRP were derived from the past atmospheric nuclear weapons tests. Also the probability plot of 239,240 Pu concentration was dependent on the shellfish species (bivalve and abalone). It was presumed that the different of feeding behavior of bivalve and abalone caused the difference of the probability plot of 239,240 Pu concentration. (author)

  11. Onboard screening dockside testing as a new means of managing paralytic shellfish poisoning risks in federally closed waters

    Science.gov (United States)

    DeGrasse, Stacey; Conrad, Stephen; DiStefano, Paul; Vanegas, Camilo; Wallace, David; Jensen, Pete; Hickey, J. Michael; Cenci, Florence; Pitt, Jaclyn; Deardorff, Dave; Rubio, Fernando; Easy, Dorothy; Donovan, Mary Anne; Laycock, Maurice; Rouse, Debbie; Mullen, John

    2014-05-01

    Paralytic shellfish poisoning (PSP) is the foodborne intoxication associated with the consumption of seafood contaminated with naturally occurring neurotoxins known as paralytic shellfish toxins. To protect public health from this potentially fatal syndrome, harvesting closures are implemented when toxins exceed the regulatory action level. Traditional monitoring programs established by state shellfish authorities allow for timely closures in state waters with minimal negative impacts on industry. However, such monitoring programs are not feasible in federal offshore waters given their distance from shore and the range of their spatial coverage. Thus innovative management strategies were investigated for these offshore resources. Georges Bank, an offshore resource with an estimated market value of more than 3 billion in Atlantic surfclams and ocean quahogs, has been closed to harvesting following a temporary ban in 1989 and a subsequent indefinite closure in 1990 due to the risk of PSP. As a means of managing this risk and allowing harvest of safe shellfish from this important resource, the Onboard Screening Dockside Testing Protocol (referred to as the Protocol) was developed by the US Food and Drug Administration (FDA), National Marine Fisheries Service (NMFS), state shellfish control authorities, and industry. The Protocol, which sets forth control measures to ensure product safety and public health protection, was endorsed by the Interstate Shellfish Sanitation Conference (ISSC) for pilot testing. Briefly, the pilot study Protocol required that (1) the fishing vessel receive a permit from NMFS to harvest in closed waters, (2) a miniμm of five shellfish samples per intended harvest lot be tested for PSP toxins onboard, and (3) harvesting only occur when the samples tested from the intended fishing area are negative using the Jellett Rapid Tests or Abraxis Shipboard ELISA kits. Finally, product landed under the Protocol was confirmed to be safe for consumption

  12. LiveOcean: A Daily Forecast Model of Ocean Acidification for Shellfish Growers

    Science.gov (United States)

    MacCready, P.; Siedlecki, S. A.; McCabe, R. M.

    2016-12-01

    The coastal estuaries of the NE Pacific host a highly productive shellfish industry, but in the past decade they have suffered from many years in which no natural set of oysters occurred. It appears that coastal waters with low Aragonite saturation state may be the cause. This "acidified" water is the result of (i) upwelling of NE Pacific water from near the shelf break that is already low in pH, and (ii) further acidification of that water by productivity and remineralization on the shelf, and (iii) increasing atmospheric CO2. As part of a coordinated research response to this issue, we have developed the LiveOcean modeling system, which creates daily three-day forecasts of circulation and biogeochemical properties in Oregon-Washington-British Columbia coastal and estuarine waters. The system includes realistic tides, atmospheric forcing (from a regional WRF model), ocean boundary conditions (from HYCOM), and rivers (from USGS and Environment Canada). The model is also used for Harmful Algal Bloom prediction. There has been extensive validation of hindcast runs for currents and hydrography, and more limited validation of biogeochemical variables. Model results are pushed daily to the cloud, and made available to the public through the NANOOS Visualization System (NVS). NVS also includes automated model-data comparisons with real-time NDBC and OOI moorings. Future work will focus on optimizing the utility of this system for regional shellfish growers.

  13. Radioactive contamination of fish, shellfish, and waterfowl exposed to Hanford effluents: Annual summaries, 1945--1972

    Energy Technology Data Exchange (ETDEWEB)

    Hanf, R.W.; Dirkes, R.L.; Duncan, J.P.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and organizations interested in evaluating aquatic pathway information for locations impacted by Hanford operations and will be useful for planning the direction of future HEDR studies.

  14. Detection of Cryptosporidium oocysts in green mussels (Perna viridis from shell-fish markets of Thailand

    Directory of Open Access Journals (Sweden)

    Srisuphanunt M.

    2009-09-01

    Full Text Available Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis, the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24 and Samut Prakan (n = 32 a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels’ cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels’ population of Samut Prakan was higher (15.6% than in Bangkok market (8.3%. These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  15. Detection of Cryptosporidium oocysts in green mussels (Perna viridis) from shell-fish markets of Thailand.

    Science.gov (United States)

    Srisuphanunt, M; Wiwanitkit, Viroj; Saksirisampant, W; Karanis, P

    2009-09-01

    Mussels filter large volumes of water and can concentrate pathogenic organisms, which may act as potential vehicles of transmission to the consumer. A survey study was carried out to investigate the presence of Cryptosporidium protozoan parasites in green mussels (Perna viridis), the smussles pecies most destined for consumption in Thailand. In total, 56 samples were examined from Bangkok (n = 24) and Samut Prakan (n = 32) a wholesale shell-fish markets located at the mouth of the Chao Phraya River. The market for green mussels was closed to the mussel culture placed along the coastal line and this localization may have significant economical impact if the mussels' cultures are found contaminated. Cryptosporidium spp. oocysts were detected by the immunofluorescence antibody method (IFA) in 12.5% of the samples examined. The detection of Cryptosporidium oocysts in green mussels' population of Samut Prakan was higher (15.6%) than in Bangkok market (8.3%). These differences in positive samples from the two locations may be caused by physical, ecological and anthropogenic conditions. This could relay to different contamination levels of marine water by Cryptosporidium oocysts and consequently to contamination of harvested shellfish populations. The results demonstrate that the Cryptosporidium spp. oocysts were found indigenous in mussels from the coastal line of Thailand, indicating that mussels may act as a reservoir of Cryptosporidium foodborne infections for humans.

  16. Apparent bioaccumulation of cylindrospermopsin and paralytic shellfish toxins by finfish in Lake Catemaco (Veracruz, Mexico).

    Science.gov (United States)

    Berry, J P; Jaja-Chimedza, A; Dávalos-Lind, L; Lind, O

    2012-01-01

    Compared to the well-characterized health threats associated with contamination of fish and shellfish by algal toxins in marine fisheries, the toxicological relevance of the bioaccumulation of toxins from cyanobacteria (blue-green algae), as the primary toxigenic algae in freshwater systems, remains relatively unknown. Lake Catemaco (Veracruz, Mexico) is a small, tropical lake system specifically characterized by a year-round dominance of the known toxigenic cyanobacterial genus, Cylindrospermopsis, and by low, but detectable, levels of both a cyanobacterial hepatotoxin, cylindrospermopsin (CYN), and paralytic shellfish toxins (PSTs). In the present study, we evaluated, using enzyme-linked immunoassay (ELISA), levels of both toxins in several species of finfish caught and consumed locally in the region to investigate the bioaccumulation of, and possible health threats associated with, these toxins as potential foodborne contaminants. ELISA detected levels of both CYN and PSTs in fish tissues from the lake. Levels were generally low (≤ 1 ng g(-1) tissue); however, calculated bioaccumulation factors (BAFs) indicate that toxin levels exceed the rather low levels in the water column and, consequently, indicated bioaccumulation (BAF >1). A reasonable correlation was observed between measured bioaccumulation of CYN and PSTs, possibly indicating a mutual source of both toxins, and most likely cells of Cylindrospermopsis, the dominant cyanobacteria in the lake, and a known producer of both metabolites. The potential roles of trophic transport in the system, as well as possible implications for human health with regards to bioaccumulation, are discussed.

  17. Identification of Salmonella serovars isolated from live molluscan shellfish and their significance in the marine environment.

    Science.gov (United States)

    Martinez-Urtaza, Jaime; Saco, Montserrat; Hernandez-Cordova, Gustavo; Lozano, Antonio; Garcia-Martin, Oscar; Espinosa, Joaquin

    2003-02-01

    A study on the presence of Salmonella spp. in live molluscs was performed, which included a description of the different serovars isolated and their relationship to the marine environment. A total of 2,980 samples of shellfish from Galicia (N.W. Spain) were tested for the presence of Salmonella spp. between September 1998 and August 2001. The overall incidence of Salmonella was 1.8% and showed a slight rise during the 3 years of the study. Mussels and oysters presented a higher incidence than clams and cockles, possibly because of their distinct growing habitat. A seasonal pattern was noted for the isolation of Salmonella spp.: 54% of the isolations were detected from September to November. That nearly 67% of the total Salmonella was isolated from shellfish with fecal coliform levels fecal coliforms do not necessarily indicate the absence of Salmonella. A total of nine serovars were found in the 54 Salmonella isolated. Salmonella Senftenberg was the most frequent (50%), followed by Salmonella Typhimurium (18%) and Salmonella Agona (17%). Salmonella Senftenberg was detected frequently during the year, whereas the remaining serovars were detected only on occasional contamination events.

  18. Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios.

    Science.gov (United States)

    Dubert, J; Fernández-Pardo, A; Nóvoa, S; Barja, J L; Prado, S

    2015-06-01

    Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. Two phytoplankton production systems were sampled weekly throughout 1-year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock. © 2015 The Society for Applied Microbiology.

  19. 137Cs levels in fish and shellfish in the Filipino diet

    International Nuclear Information System (INIS)

    Duran, E.B.; De Vera, C.M.; Enriquez, E.B.; Yulo-Nazarea, M.T.; Asada, A.A.

    1996-01-01

    Among the artificially produced radionuclides, 137 Cs is considered the most significant contributor to radiation dose due to consumption of marine products. 137 Cs is present in the marine environment as a result of atmospheric nuclear weapons tests and nuclear accidents. 137 Cs was analyzed in predominant fisn and shellfish species in the Filipino diet and in seawater collected from major fishing grounds. The mean activity concentration of 137 Cs in thirteen fish species which are commonly eaten by Filipinos was 0.53 ± 0.47 Bq kg -1 wet edible fraction (E.F.). In molluscs, the mean activity concentration measured was 0.24 ± 0.20 Bq kg -1 wet E.F. A similar value of 0.23 ± 0.12 Bq kg -1 was observed in crustaceans. A mean activity concentration of 4.76 ± 2.66 was observed in seawater which suggests approximate concentration factors of 100 for 137 Cs in fish and 40 for 137 Cs in shellfish. (author). 6 refs., 1 fig., 4 tabs

  20. Radioactive contamination of fish, shellfish, and waterfowl exposed to Hanford effluents: Annual summaries, 1945--1972

    International Nuclear Information System (INIS)

    Hanf, R.W.; Dirkes, R.L.; Duncan, J.P.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and organizations interested in evaluating aquatic pathway information for locations impacted by Hanford operations and will be useful for planning the direction of future HEDR studies

  1. Estuarine shellfish

    Digital Repository Service at National Institute of Oceanography (India)

    Matondkar, S.G.P.; Mhamal, N.; Kavlekar, D

    stream_size 2 stream_content_type text/plain stream_name Biodiversity_Western_Ghats_Inf_Kit_1994_3.7_1.pdf.txt stream_source_info Biodiversity_Western_Ghats_Inf_Kit_1994_3.7_1.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  2. Identification of Mercury in Tembang Fish (Sardinella gibbosa and Shellfish (Marcia hiantina in Losari Coastal Beach, Makassar

    Directory of Open Access Journals (Sweden)

    Erlani Erlani

    2017-06-01

    Full Text Available Mercury was one of heavy metals that became pollutant. High level of mercury in aquatic environment could cause adverse effects on living organisms in that environment, even endanger human health in using the water and consuming the organism. This reasearch was a descriptive survey that was supported by laboratory test result in order to know mercury (Hg level in Tembang fish (Sardinella gibbosa and Shellfish (Marcia hiantina in Losari coastal beach, Makassar. The result of mercury examination at Center Health Laboratory Makasar was obtained that mercury levels in Tembang Fish were 0.0150 mg/kg, 0.0133 mg/kg and 0.0126 mg/kg. Thus, the average of mercury level in Tembang fish was 0.0409 mg/kg. Meanwhile, based on examination results of mercury level in Shellfish at Center Health Laboratory, Makasar, were obtained 0.0228 mg/kg, 0.0266 mg/kg, and 0.1105 mg/kg. Thus, the average of mercury level in Shellfish was 0.1599 mg/kg. Moreover, mercury level in either Tembang fish or Shellfish in ​​Losari coastal beach Makassar had fulfilled the requirement based on SNI 7387/2009 regarding Maximum Limit of Heavy Metal of Mercury.

  3. Determinants of the consumption of fish and shellfish in Denmark: An application of the Theory of Planned Behavior

    DEFF Research Database (Denmark)

    Bredahl, Lone; Grunert, Klaus G.

    1995-01-01

    Consumers differ considerably in the degree to which they eat fish and shell-fish relative to other meat types. In this study, the Theory of Planned Behaviour (Ajzen, 1985) was used to explain intention to buy three specific sea-food categories ­ fish, frozen fish and shelled shrimps. The impact...

  4. PCDD and PCDF exposures among fishing community through intake of fish and shellfish from the Straits of Malacca.

    Science.gov (United States)

    Azlan, Azrina; Nasir, Nurul Nadiah Mohamad; Shamsudin, Norashikin; Rahman, Hejar Abdul; Khoo, Hock Eng; Razman, Muhammad Rizal

    2015-07-21

    Exposure to PCDD/PCDF (dioxin and furan) through consumption of fish and shellfish is closely related to the occurrence of skin diseases, such as chloracne and hyperpigmentation. This study aimed to determine the exposure of PCDD/PCDF and its congeners in fish and shellfish obtained from different regions of the Straits of Malacca among the fishing community. The risk of fish and shellfish consumption and exposure to PCDD/PCDF among fishermen living in coastal areas of the Straits were evaluated based on a cross-sectional study involving face to face interviews, blood pressure and anthropometric measurements, and administration of food frequency questionnaires (FFQ). Skin examination was done by a dermatologist after the interview session. Determination of 17 congeners of PCDD/PCDF in 48 composite samples of fish and shellfish was performed based on HRGC/HRMS analysis. The total PCDD/PCDF in the seafood samples ranged from 0.12 to 1.24 pg WHO-TEQ/g fresh weight (4.6-21.8 pg WHO-TEQ/g fat). No significant difference found for the concentrations of PCDD/PCDF between the same types of seafood samples obtained from the three different regions. The concentrations of the most potent congener, 2,3,7,8-TCDD in the seafood samples ranged from 0.01 to 0.11 pg WHO-TEQ/g FW (1.9 pg WHO-TEQ/g fat). A positive moderate correlation was found between the fat contents and concentrations of PCDD/PCDF determined in the seafood samples. The total PCDD/PCDF in all seafood samples were below the 1 pg WHO-TEQ/g fresh weight, with the exception of grey eel-catfish. The respondents had consumed fish and shellfish with the amounts ranging between 2.02 g and 44.06 g per person per day. The total PCDD/PCDF exposures through consumption of fish and shellfish among the respondents were between 0.01 and 0.16 pg WHO-TEQ/kg BW/day. With regard to the two PCDD/PCDF-related skin diseases, no chloracne case was found among the respondents, but 2.2% of the respondents were diagnosed to have

  5. Climate relationships to fecal bacterial densities in Maryland shellfish harvest waters.

    Science.gov (United States)

    Leight, A K; Hood, R; Wood, R; Brohawn, K

    2016-02-01

    Coastal states of the United States (US) routinely monitor shellfish harvest waters for types of bacteria that indicate the potential presence of fecal pollution. The densities of these indicator bacteria in natural waters may be related to climate in several ways, including through runoff from precipitation and survival related to water temperatures. The relationship between interannual precipitation and air temperature patterns and the densities of fecal indicator bacteria in shellfish harvest waters in Maryland's portion of the Chesapeake Bay was quantified using 34 years of data (1979-2013). Annual and seasonal precipitation totals had a strong positive relationship with average fecal coliform levels (R(2) = 0.69) and the proportion of samples with bacterial densities above the FDA regulatory criteria (R(2) = 0.77). Fecal coliform levels were also significantly and negatively related to average annual air temperature (R(2) = -0.43) and the average air temperature of the warmest month (R(2) = -0.57), while average seasonal air temperature was only significantly related to fecal coliform levels in the summer. River and regional fecal coliform levels displayed a wide range of relationships with precipitation and air temperature patterns, with stronger relationships in rural areas and mainstem Bay stations. Fecal coliform levels tended to be higher in years when the bulk of precipitation occurred throughout the summer and/or fall (August to September). Fecal coliform levels often peaked in late fall and winter, with precipitation peaking in summer and early fall. Continental-scale sea level pressure (SLP) analysis revealed an association between atmospheric patterns that influence both extratropical and tropical storm tracks and very high fecal coliform years, while regional precipitation was found to be significantly correlated with the Atlantic Multidecadal Oscillation and the Pacific North American Pattern. These findings indicate that management of

  6. FISH AND SHELLFISH PRODUCTS DISTRIBUTED BY "ETHNIC" MINI-MARKET: CONFORMITY ASSESSMENT TO CURRENT LEGISLATION

    Directory of Open Access Journals (Sweden)

    I. Giorgi

    2012-08-01

    Full Text Available The purpose of this study was to conduct an assessment on the quality and methods for marketing of fish products sold by ethnic minimarket. Has been inspected 20 supermarkets and buyed 60 fish and shellfish samples. The neatness of the rooms were evaluated during the shopping in the markets. Products purchased in the supermarket (about three samples for each shop were brought in Ichthypathology laboratory of State Veterinary Institute of Piedmont, Liguria and Aosta Valley, in Turin. Were conducted in the laboratory the readings of the labels. The conditions of hygiene were poor, especially in supermarket freezers. Only 16 samples were labelled in accordance with current legislation. According to the results obtained, the products 'ethnic' distributed in the supermarkets visited, may be considered a potential risk to human health.

  7. Radionuclides in shellfishes collected on and off the coast of Fukushima

    International Nuclear Information System (INIS)

    Ogata, Yoshimune; Minowa, Haruka; Satou, Yukihiko; Kojima, Sadao

    2012-01-01

    Huge amount of radioactive material was released into the atmosphere and the sea by the disaster of Fukushima Dai-ichi NPP, TEPCO. Some elements tend to concentrate in certain species by food chain in marline lives. We collected several species of shellfishes in the coast and offshore area of Fukushima Prefecture, and analysed them by gamma-ray spectroscopy. Japanese Grata Limpet, Japanese oyster, Common Blue Mussel, Arthritic Whelks, and Purple sea urchin was collected. The shells and bodies were dried up, and were measured with a high-pure Ge detector. The activity concentration (Bq/kg) was calculated by the activity divided by the raw weight. Certain amounts of radiocaesiums ("1"3"4Cs and "1"3"7Cs) were detected in all of the bodies. And "1"1"0"mAg was detected in limpet, oyster, and whelks. The concentrations of the radionuclides were ranged from not-detectable level (∼ 0.1 Bq/kg) to 300 Bq/kg. Although oyster and mussel were collected at the same place, oyster included "1"1"0"mAg and mussel did not. While whelks and sea urchin was caught at the same offshore area, whelks had relative high "1"1"0"mAg and sea urchin did not. The ratios of "1"1"0"mAg to "1"3"7Cs were three to ten for limpet and whelks, and the ratios were different for each species. Some shellfishes were confirmed to concentrate "1"1"0"mAg in their bodies. Not only radiocaesiums but also radiosilver should be noticed to monitor fishes. (author)

  8. Screening and evaluation of local bacteria isolated from shellfish as potential probiotics against pathogenic Vibrios.

    Science.gov (United States)

    Jasmin, M Y; Wagaman, Hazimah; Yin, Tan Ai; Ina-salwany, M Y; Daud, H M; Karim, Murni

    2016-07-01

    The present study was carried out to isolate, screen and evaluate potential candidates of local bacteria isolated from tiger shrimp Penaeus monodon and slipper cupped oysters Crassostrea iredalei as probiotics in shellfish aquaculture. A total of 144 of bacteria were successfully isolated from the intestine and stomach of 20 tails of healthy adult tiger shrimp P. monodon, while 136 were successfully isolated from the digestive tract, gills and inner shells of 10 healthy adult C. iredalei. The number of potential isolates was narrowed down to two from tiger shrimp, and one from slipper cupped oyster after in vitro screening assays. The three isolates, labeled as G11, I24 and S66, were identified as Virgibacillus sp., Bacillus sp. and Exiquobacterium sp., respectively, using 16S rDNA gene analysis. The antagonistic ability of the isolates towards Vibrio alginolyticus and Vibrio harveyi were conducted in stagnant and liquid modes via spot lawn and broth co-culture assay, respectively. In these assays, all the potential probionts were inhibitory to both pathogenic vibrios. In the in-vivo assay, Artemia was used as host and treated with different concentrations of potential probionts (10(4), 10(6) and 10(8) CFU ml(-1)), and challenged with V. alginolyticus and V. harveyi at 105 CFU ml(-1), respectively. Artemia treated with probiont G11 at all concentrations and challenged with V. alginolyticus had increased survival (70 ? 80 %), which was significantly higher as compared with group with only the pathogen (20 %). Meanwhile, probiont I24 increased the survival of Artemia by 70 % at a concentration of 10(8) CFU ml(-1) after being challenged with V. alginolyticus and Artemia treated with 10(6) CFU ml(-1) of probiont S66 had increased survival of 90% after being challenged with V. harveyi. Thus, the three isolates might have potential applications as probiotics in shellfish aquaculture against vibriosis. ?

  9. Lethal paralytic shellfish poisoning from consumption of green mussel broth, Western Samar, Philippines, August 2013

    Directory of Open Access Journals (Sweden)

    Paola Katrina Ching

    2015-05-01

    Full Text Available Background: In July 2013, the Philippines’ Event-Based Surveillance & Response Unit received a paralytic shellfish poisoning (PSP report from Tarangnan, Western Samar. A team from the Department of Health conducted an outbreak investigation to identify the implicated source and risk factors in coastal villages known for green mussel production and exportation. Methods: A case was defined as a previously well individual from Tarangan, Western Samar who developed gastrointestinal symptoms and any motor and/or sensory symptoms after consumption of shellfish from 29 June to 4 July 2013 in the absence of any known cause. The team reviewed medical records, conducted active case finding and a case-control study. Relatives of cases who died were interviewed. Sera and urine specimens, green mussel and seawater samples were tested for saxitoxin levels using high performance liquid chromatography. Results: Thirty-one cases and two deaths were identified. Consumption of >1 cup of green mussel broth was associated with being a case. Seawater sample was positive for Pyrodinium bahamense var. compressum and green mussel samples were positive for saxitoxin. Inspection revealed villagers practice open defecation and improper garbage disposal. Conclusion: This PSP outbreak was caused by the consumption of the green mussel broth contaminated by saxitoxin. As a result of this outbreak, dinoflagellate and saxitoxin surveillance was established, and since the outbreak, there have been no harmful algal blooms event or PSP case reported since. A “Save Cambatutay Bay” movement, focusing on proper waste disposal practice and clean-up drives has been mobilized.

  10. Prevalence and characterization of Shiga Toxin-producing and enteropathogenic Escherichia coli in shellfish-harvesting areas and their watersheds

    Directory of Open Access Journals (Sweden)

    Balière eCharlotte

    2015-12-01

    Full Text Available During a two-year study, the presence of Shiga-toxin producing E. coli (STEC and enteropathogenic E. coli (EPEC was investigated in shellfish (n=238, seawater (n=12 and surface sediment (n=39 collected from three French coastal shellfish-harvesting areas and freshwaters (n=216 in their watersheds. PCR detection of Shiga toxin- (stx1/stx2 and intimin- (eae genes following enrichment from these samples revealed the presence of least one of the stx genes in 30.3% of shellfish batches, 85.9% of freshwater, 41.7% of seawater, and 28.2% of sediment samples, while the eae gene was observed in 74.8%, 100%, 100%, and 43.6% of shellfish batches, freshwater, seawater, and sediment samples, respectively. Twenty-eight STEC and 89 EPEC strains were isolated and analyzed in order to determine their serotype, phylogroup, and genetic relatedness and to evaluate the presence of the saa and ehxA genes encoding the STEC autoagglutinating adhesin and the enterohemolysin A, respectively. Finally, the ability to form biofilms and antimicrobial susceptibility were investigated for a selection of strains. Eighteen serotypes were identified among the STEC isolates and 57 among the EPEC isolates. A high diversity was observed within these strains, as 79 different PFGE patterns and 48 distinguishable sequence types were identified. Strains were found to belong mainly to phylogroups B1 and B2 and virulence was observed to be low as more than 85% of the strains possessed only stx1, stx2 or eae genes. One STEC and several EPEC strains belonged to three of the five highly pathogenic serogroups (i.e., O26, O103, and O145. The subset of strains tested for their capacity to form biofilms was mainly strongly to moderately adherent and more strains formed a strong biofilm at 18°C than at 30°C. Finally, more than 85% of analyzed strains were found to be sensitive to the 16 tested antibiotics. These data suggest the low risk of human infection by STEC if shellfish from these

  11. Climate change impacts on natural toxins in food production systems, exemplified by deoxynivalenol in wheat and diarrhetic shellfish toxins.

    Science.gov (United States)

    van der Fels-Klerx, H J; Olesen, J E; Naustvoll, L-J; Friocourt, Y; Mengelers, M J B; Christensen, J H

    2012-01-01

    Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal grains cultivated in the terrestrial area of north west Europe, and on the frequency of harmful algal blooms and contamination of shellfish with marine biotoxins in the North Sea coastal zone. The study focused on contamination of wheat with deoxynivalenol, and on abundance of Dinophysis spp. and the possible relationship with diarrhetic shellfish toxins. The study used currently available data and models. Global and regional climate models were combined with models of crop phenology, mycotoxin prediction models, hydrodynamic models and ecological models, with the output of one model being used as input for the other. In addition, statistical data analyses using existing national datasets from the study area were performed to obtain information on the relationships between Dinophysis spp. cell counts and contamination of shellfish with diarrhetic shellfish toxins as well as on frequency of cereal cropping. In this paper, a summary of the study is presented, and overall conclusions and recommendations are given. Climate change projections for the years 2031-2050 were used as the starting point of the analyses relative to a preceding 20-year baseline period from which the climate change signal was calculated. Results showed that, in general, climate change effects lead to advanced flowering and harvest of wheat, and increased risk of contamination of wheat with deoxynivalenol. Blooms of dinoflagellates were estimated to occur more often. If the group of Dinophysis spp. behaves similarly to other flagellates in the future then frequency of harmful algal blooms of Dinophysis spp. may also increase, but consequences for contamination of shellfish with diarrhetic shellfish

  12. Digest of data from the measurement of radioactivity in the Irish Marine Environment 1982-1984. Part I: Fish and Shellfish

    International Nuclear Information System (INIS)

    O'Grady, John

    1985-11-01

    Levels of radioactivity in fish and shellfish have been measured at the National Radiation Monitoring Service since 1982. These measurement are part of the Nuclear Energy Board's radioactivity monitoring of the marine environment. The main effort was directed at the measurement of radioactivity, in particular radiocaesium, in fish and shellfish from the Irish Sea where the polluting effect of radioactive wastes from the nuclear fuel reprocessing plant at Sellafield is greatest. The measured levels of Cs-137 and Cs-134 in the popular species of fish and shellfish allow the estimation of the population dose to the Irish public as a result of eating seafood contaminated with radiocaseium. This report attempts to set out, in summarised form, a comprehensive review of sampling, analytical and dose assessment details for the three-year period 1982 to 1984. Levels of K-40, the naturally occurring radionuclide, in the fish and shellfish samples are also reported. (author)

  13. EPA oyster project: nitrogen in water. - Transport and fate of nutrient and pathogen loadings into nearshore Puget Sound: consequences for shellfish growing areas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project seeks to develop and apply an assessment of shellfish growing area (SGA) vulnerability to closures caused by watershed- and marine-derived pathogens....

  14. Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method Coupled with Dispersive Solid-Phase Extraction for Simultaneous Quantification of Eight Paralytic Shellfish Poisoning Toxins in Shellfish

    Science.gov (United States)

    Yang, Xianli; Zhou, Lei; Tan, Yanglan; Shi, Xizhi; Zhao, Zhiyong; Nie, Dongxia; Zhou, Changyan; Liu, Hong

    2017-01-01

    In this study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for simultaneous determination of eight paralytic shellfish poisoning (PSP) toxins, including saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins (GTX1–4) and the N-sulfo carbamoyl toxins C1 and C2, in sea shellfish. The samples were extracted by acetonitrile/water (80:20, v/v) with 0.1% formic and purified by dispersive solid-phase extraction (dSPE) with C18 silica and acidic alumina. Qualitative and quantitative detection for the target toxins were conducted under the multiple reaction monitoring (MRM) mode by using the positive electrospray ionization (ESI) mode after chromatographic separation on a TSK-gel Amide-80 HILIC column with water and acetonitrile. Matrix-matched calibration was used to compensate for matrix effects. The established method was further validated by determining the linearity (R2 ≥ 0.9900), average recovery (81.52–116.50%), sensitivity (limits of detection (LODs): 0.33–5.52 μg·kg−1; limits of quantitation (LOQs): 1.32–11.29 μg·kg−1) and precision (relative standard deviation (RSD) ≤ 19.10%). The application of this proposed approach to thirty shellfish samples proved its desirable performance and sufficient capability for simultaneous determination of multiclass PSP toxins in sea foods. PMID:28661471

  15. Temporal genetic variability and host sources of Escherichia coli associated with fecal pollution from domesticated animals in the shellfish culture environment of Xiangshan Bay, East China Sea

    International Nuclear Information System (INIS)

    Fu Linglin; Shuai Jiangbing; Wang Yanbo; Ma Hongjia; Li Jianrong

    2011-01-01

    This study was conducted to analyze the genetic variability of Escherichia coli from domesticated animal wastes for microbial source tracking (MST) application in fecal contaminated shellfish growing waters of Xiangshan Bay, East China Sea. (GTG) 5 primer was used to generate 1363 fingerprints from E. coli isolated from feces of known 9 domesticated animal sources around this shellfish culture area. Jackknife analysis of the complete (GTG) 5 -PCR DNA fingerprint library indicated that isolates were assigned to the correct source groups with an 84.28% average rate of correct classification. Based on one-year source tracking data, the dominant sources of E. coli were swine, chickens, ducks and cows in this water area. Moreover, annual and spatial changes of E. coli concentrations and host sources may affect the level and distribution of zoonotic pathogen species in waters. Our findings will further contribute to preventing fecal pollution in aquatic environments and quality control of shellfish. - Highlights: → The host-origin library developed by (GTG) 5 -PCR could be used to shellfish water MST. → Fecal pollution of Xiangshan Bay arose from multiple sources of agricultural wastes. → High level of E. coli concentration in shellfish water increases the health risk. → Annual changes of E. coli host sources affect distribution of zoonotic pathogens. - The temporal genetic variability and dominant host sources of E. coli in fecal contaminated shellfish growing waters of Xiangshan Bay was characterized.

  16. The Association between the Consumption of Fish/Shellfish and the Risk of Osteoporosis in Men and Postmenopausal Women Aged 50 Years or Older

    Directory of Open Access Journals (Sweden)

    Eunjin Choi

    2016-02-01

    Full Text Available Fish rich in n-3 polyunsaturated fatty acids have been suggested to have a favorable effect on bone health, but previous epidemiologic studies have shown inconsistent results. The purpose of the present study was to investigate the hypothesis that the consumption of fish and shellfish is positively associated with bone mass and negatively associated with the risk of osteoporosis in Koreans and Americans. Men and postmenopausal women ≥50 years old from the Korean National Health and Nutrition Examination Survey 2008–2011 (n = 7154 and the National Health and Nutrition Examination Survey 2007–2010 (n = 2658 were included. There was a positive correlation between the consumption of fish and shellfish and bone mineral density (BMD of the total femur, femoral neck, and lumbar spine in Koreans. Consistently, multivariate logistic regression analysis showed a significant association between intake of fish and shellfish and the risk of osteoporosis in Koreans but not in Americans. Consumption of fish and shellfish was 4–5 times higher in Koreans than Americans in the present study. In conclusion, intake of fish and shellfish was associated with BMD and the risk of osteoporosis in Koreans but not in Americans, suggesting that a minimum intake level of fish and shellfish might be recommended to protect against bone loss and osteoporosis.

  17. Azaspiracid Shellfish Poisoning: A Review on the Chemistry, Ecology, and Toxicology with an Emphasis on Human Health Impacts

    Directory of Open Access Journals (Sweden)

    Gregory J. Doucette

    2008-05-01

    Full Text Available Azaspiracids (AZA are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 μg AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the European legislature associated with AZAs.

  18. Detection of Total and Pathogenic Vibrio parahaemolyticus in Shellfish Growing along the South Yellow Sea and the East China Sea.

    Science.gov (United States)

    Han, Feng; Gu, Run-Run; Shen, Xiao-Sheng; Chen, Yuan-Ge; Tian, Liang-Liang; Zhou, Wei-Feng; Cai, You-Qiong

    2017-10-17

    This study was conducted to monitor the densities of total and pathogenic Vibrio parahaemolyticus in 300 samples of nine shellfish species harvested from the coasts of the South Yellow Sea and the East China Sea (N 23° to 34°, E 116° to 124°), People's Republic of China, between May and October 2015. Total V. parahaemolyticus densities were measured, and V. parahaemolyticus isolates were biochemically identified with probes for the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh). We found that 202 of the 300 samples were positive for V. parahaemolyticus from all the sites: 58 of the 100 samples from the Fujian province, 71 of the 100 samples from the Zhejiang province, and 73 of the 100 samples from the Jiangsu province. In most (170) of the 300 samples, V. parahaemolyticus densities were 0.3 to 10 most probable number (MPN)/g; five lots exceeded 110 MPN/g, and two lots were estimated at 110 MPN/g. Among the 202 V. parahaemolyticus strains, only one was trh positive. Densities of V. parahaemolyticus in these shellfish were temperature dependent, with highest densities in June and July. Among the nine mollusk species, V. parahaemolyticus was most abundant in the agemaki clam (Sinonovacula constricta). The highest and lowest V. parahaemolyticus prevalences were found in oriental cyclina (Cyclina sinensis, 93.8%) and mussels (Mytilus edulis, 28.1%), respectively. Overall, although V. parahaemolyticus is widely distributed in marine environments, the density of V. parahaemolyticus was low and the prevalence of the main virulence factor was very low in shellfish along the coasts of the South Yellow Sea and East China Sea, which is important from a public health perspective. Data presented here will be useful for correlational research and can be utilized for developing risk management plans that establish food safety guidelines for V. parahaemolyticus in Chinese shellfish.

  19. Ranking the contributions of commercial fish and shellfish varieties to mercury exposure in the United States: implications for risk communication.

    Science.gov (United States)

    Groth, Edward

    2010-04-01

    Fish and shellfish have important nutritional benefits, and US per capita seafood consumption has increased substantially since 2002. Recent research has reinforced concerns about adverse effects of methylmercury exposure, suggesting that methylmercury doses associated with typical US rates of fish consumption may pose measurable risks, with no threshold. These converging trends create a need to improve risk communication about fish consumption and mercury. The analysis performed here identifies the relative importance of different fish and shellfish as sources of mercury in the US seafood supply and proposes improved consumer advice, so that the public can benefit from fish consumption while minimizing mercury exposure. I have quantified contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, then ranked and sorted the 51 varieties in terms of relative impact. Except for swordfish, most fish with the highest mercury levels are relatively minor contributors to total inputs. Tuna (canned light, canned albacore and fresh/frozen varieties) accounts for 37.4 percent of total mercury inputs, while two-thirds of the seafood supply and nine of the 11 most heavily consumed fish and shellfish are low or very low in mercury. Substantial improvement in risk communication about mercury in fish and seafood is needed; in particular, several population subsets need better guidance to base their seafood choices more explicitly on mercury content. I have sorted the 51 seafood varieties into six categories based on mercury levels, as a framework for improving risk communication in this regard. (c) 2009 Elsevier Inc. All rights reserved.

  20. BMAA in shellfish from two Portuguese transitional water bodies suggests the marine dinoflagellate Gymnodinium catenatum as a potential BMAA source.

    Science.gov (United States)

    Lage, Sandra; Costa, Pedro Reis; Moita, Teresa; Eriksson, Johan; Rasmussen, Ulla; Rydberg, Sara Jonasson

    2014-07-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) and its putative role in multiple neurodegenerative diseases have been intensely studied since 2005 when the toxin was discovered to be produced by worldwide-distributed cyanobacterial species inhabiting terrestrial, marine, brackish, and freshwater ecosystems. Recently, BMAA production was also associated with one eukaryotic group, namely, diatoms, raising questions about its production by other phytoplanktonic groups. To test for BMAA bioavailability in ecosystems where abundant phytoplanktonic blooms regularly occur, samples of filter-feeding shellfish were collected in two Portuguese transitional water bodies. BMAA content in cockles (Cerastoderma edule) collected weekly between September and November 2009 from Ria de Aveiro and at least once a month from May to November from Ria Formosa, fluctuated from 0.079±0.055 to 0.354±0.066μg/g DW and from below the limit of detection to 0.434±0.110μg/g DW, respectively. Simultaneously to BMAA occurrence in cockles, paralytic shellfish toxins were detected in shellfish as a result of Gymnodinium catenatum blooms indicating a possible link between this marine dinoflagellate and BMAA production. Moreover, considerable high BMAA levels, 0.457±0.186μg/g DW, were then determined in a laboratory grown culture of G. catenatum. This work reveals for the first time the presence of BMAA in shellfish from Atlantic transitional water bodies and consubstantiate evidences of G. catenatum as one of the main sources of BMAA in these ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. A Simple Model to Rank Shellfish Farming Areas Based on the Risk of Disease Introduction and Spread.

    Science.gov (United States)

    Thrush, M A; Pearce, F M; Gubbins, M J; Oidtmann, B C; Peeler, E J

    2017-08-01

    The European Union Council Directive 2006/88/EC requires that risk-based surveillance (RBS) for listed aquatic animal diseases is applied to all aquaculture production businesses. The principle behind this is the efficient use of resources directed towards high-risk farm categories, animal types and geographic areas. To achieve this requirement, fish and shellfish farms must be ranked according to their risk of disease introduction and spread. We present a method to risk rank shellfish farming areas based on the risk of disease introduction and spread and demonstrate how the approach was applied in 45 shellfish farming areas in England and Wales. Ten parameters were used to inform the risk model, which were grouped into four risk themes based on related pathways for transmission of pathogens: (i) live animal movement, (ii) transmission via water, (iii) short distance mechanical spread (birds) and (iv) long distance mechanical spread (vessels). Weights (informed by expert knowledge) were applied both to individual parameters and to risk themes for introduction and spread to reflect their relative importance. A spreadsheet model was developed to determine quantitative scores for the risk of pathogen introduction and risk of pathogen spread for each shellfish farming area. These scores were used to independently rank areas for risk of introduction and for risk of spread. Thresholds were set to establish risk categories (low, medium and high) for introduction and spread based on risk scores. Risk categories for introduction and spread for each area were combined to provide overall risk categories to inform a risk-based surveillance programme directed at the area level. Applying the combined risk category designation framework for risk of introduction and spread suggested by European Commission guidance for risk-based surveillance, 4, 10 and 31 areas were classified as high, medium and low risk, respectively. © 2016 Crown copyright.

  2. Testing the potential effects of shellfish farming on swimming activity and spatial distribution of sole (Solea solea) in a mesocosm

    OpenAIRE

    Laffargue, Pascal; Begout, Marie-laure; Lagardere, Francoise

    2006-01-01

    Restructuring coastal fish nursery habitats by extensive shellfish fanning in the French part of the Bay of Biscay could influence fish physiology and behaviour and affect the ecological performance of the species. The influence of oyster-trestle cultivation installations on sole (Solea solea) swimming behaviour was investigated using an experimental pond mesocosm. A pen was constructed with three interconnected zones (two with bags of live oysters or oyster shells on trestles, and one free z...

  3. A comparative study for PSP toxins quantification by using MBA and HPLC official methods in shellfish.

    Science.gov (United States)

    Ben-Gigirey, B; Rodríguez-Velasco, M L; Otero, A; Vieites, J M; Cabado, A G

    2012-10-01

    Commission Regulation (EC) N° 2074/2005 recognises the biological method as the reference method for Paralytic Shellfish Poisoning (PSP) toxins detection in molluscs. It was amended by Commission Regulation (EC) N° 1664/2006 that accepted the so-called Lawrence method as an alternative to the reference method. The goal of this study was to compare AOAC Official Methods of Analysis 959.08 (Biological method) and 2005.06 (Prechromatographic Oxidation and Liquid Chromatography with fluorescence detection) in samples with different toxin profiles. The influence of extraction solvent in the total samples toxicity was also evaluated. A total of 40 samples including mussels, clams, scallops, razor-clams, cockles, oysters and barnacles were analysed by both official methods. Samples were selected with Alexandrium and Gymnodinium toxic profiles, from different origin and including several presentations: fresh, frozen, canned and boiled. Acetic and hydrochloric acid extractions were performed in all samples and the extracts were simultaneously analysed by both methods. Most samples were naturally contaminated and two samples were spiked. Comparison of both official methods, mouse bioassay (MBA) with HCl extraction and Liquid Chromatography with fluorescence detection (HPLC-FLD) with acetic acid extraction, led to an 85% of consistent results regarding compliance with legal limit, including samples below and above it. The linear correlation coefficient was r² = 0.69 and the paired t test (two tails, α = 0.05) indicated that there were not significant differences among both sets of data. Nevertheless, toxicity differences were found in several samples. In 15 out of 18 shellfish with a Gymnodinium toxic profile, higher toxicity levels were obtained by MBA. This fact was more evident in 7 samples, partially related to the lack of standards and the impossibility of analysing dc-NEO, C1, 2 and GTX6 at the beginning of the study. However, other factors concerning the extraction

  4. Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.

    Science.gov (United States)

    Olmedo, P; Pla, A; Hernández, A F; Barbier, F; Ayouni, L; Gil, F

    2013-09-01

    Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead). Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Some results of recent surveys of fish and shellfish consumption by age and region of U.S. residents

    International Nuclear Information System (INIS)

    Rupp, E.M.; Baes, C.F. III; Miller, F.L.

    1980-01-01

    Since ingestion of foods is considered a major source of pollutant intake by man, the knowledge of detailed food consumption patterns is necessary to determine health risks and compliance with regulatory standards. As currently available literature lacks data necessary for complete evaluation of aquatic foods via human consumption of fish and shellfish, a review of recent surveys of fish consumption in the U.S. was performed. The data in these surveys were subjected to statistical analysis to determine percentage distributions of individuals eating different quantities of marine and freshwater fish and shellfish. Included are surveys on consumption of sportfish from the Columbia River and Lake Michigan areas and a comprehensive study of fish consumption in the nine census regions of the U.S. The results of these studies indicate that the quantity, as reported, of each type of fish eaten increases as a function of the age of consumers. Regional differences are most apparent in the use of shellfish and freshwater fish. About 94% of children and 96-100% of adults eat some kind of fish with a per capita average of 4.97 kg/yr. Since this quantity is on an actual consumption basis, as as opposed to 'as purchased', the per capita consumption rate is lower than usually reported in the literature. (author)

  6. Characterization of organochlorine pesticides, brominated flame retardants and dioxin-like compounds in shellfish and eel from Fiji.

    Science.gov (United States)

    Lal, Vincent; Bridgen, Phil; Votadroka, Waisea; Raju, Rupantri; Aalbersberg, William

    2014-09-01

    This article gives an overview of a range of persistent organic pollutant chemical levels in shellfish (Batissa violacea and Anadara antiquata) species and eel (Gymnothorax flavimarginatus) from Fiji. As there is limited data in published literature to date, this paper reports first data on a range of persistent organic pollutants and highlights the more prominent POP chemicals present in marine biota in Fiji. A significant number of POP chemicals were detected (e.g. 17 PCDD/PCDF, 12dl-PCBs, organochlorine pesticides and brominated flame retardants), the concentrations found were generally low (e.g. parts per billion level). The low levels of contamination are indicative of a low input from long range and short-range transport as well as few local point sources. Also concentrations of POPs in eel and shellfish from Fiji are low in comparison to wild species in other regions and are within acceptable limits for POP chemicals in fish and fishery products set by the European Union. It describes also results of early studies on basic POPs levels in shellfish in several Pacific Island Countries, which generally show relatively low levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The distribution, contamination and risk assessment of heavy metals in sediment and shellfish from the Red Sea coast, Egypt.

    Science.gov (United States)

    El Nemr, Ahmed; El-Said, Ghada F; Ragab, Safaa; Khaled, Azza; El-Sikaily, Amany

    2016-12-01

    Zn, Cu, Ni, V, Al, Pb, Cd, Hg, lipid and water contents were determined in the soft tissues of different shellfish species collected along the Red Sea shoreline. Metal contents showed a descending order of Zn > Cu > Ni > Al > V > Pb > Cd > Hg. The leachable concentrations found in the sediments gathered from the studied locations gave another descending order: Al > Zn > Ni > Pb > V > Cu > Cd. The determined leachable heavy metal contents in the sediment did not exceed the NOAA and CCME (Anonymous 1999) sediment quality guidelines. Accordingly, the sediments along the Egyptian Red Sea area did not pose any adverse impacts on the biological life. According to the hazard quotient (HQ) calculations for heavy metal contents in the soft tissue of shellfish, mercury did not pose any risk on human health; whereas, the other determined heavy metals gave HQ values of 1 < HQ < 10 and showed a possibility of risk on the long term. Cu is above the desirable levels in mussels. The RQ calculations of toddlers and adults reflected that Cu was the only heavy metal that had an adverse effect on toddlers' health. Based on the human organizations (EPA, BOE, MAFF, and NHMRC) that proposed safety concentrations of heavy metals, the studied shellfish were somewhat safe for human consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Depuration of shellfish by irradiation: Final technical report, October 1, 1987--March 31, 1989

    International Nuclear Information System (INIS)

    Beghian, L.E.; Mallett, J.C.

    1989-01-01

    Studies by the University of Lowell Radiation Laboratory and the US National Marine Fisheries Service N.E. Laboratory in Gloucester, MA on softshelled clams (Mya arenaria) demonstrated the effectiveness of low to medium doses of Cobalt 60 source gamma irradiation in the inactivation of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Streptococcus faecalis. Post-irradiation survival and organoleptic studies when extended to hardshelled clams (Mercinaria mercenaria) and American oysters (Crassostrea virginica) showed no significant decline in consumer qualities or 6 day post irradiation survival in oysters at doses of up to 3.0 kGy. The capacities of the American oyster to sustain relatively high doses of gamma irradiation were demonstrated by 6 day post-exposure survivorship values of greater than 90% for samples receiving 3.0, 5.0 and 7.0 kGy. Initial studies of inactivation of Polio I virus and a simian rotavirus (SA-11) was conducted in both hardshelled clams and oysters. Of greatest interest was the behavior of Hepatitis A virus (HAV), in live, irradiated shellfish. The average log decrement value for HAV in oysters was calculated at 2.0 kGy. From these data it appears that doses of up to 2 kGy can be applied to: reduce or eliminate bacterial pathogens, reduce the infectivity of human viral pathogens by one or more orders of magnitude, and preserve market qualities of longevity, appearance, odor, taste and texture. 23 refs., 11 figs., 3 tabs

  9. Irradiation of fish, shellfish and frog legs. A compilation of technical data for authorization and control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-01

    The International Consultative Group on Food Irradiation (ICGFI) was established on 9 May 1984 under the aegis of FAO, IAEA and WHO. ICGFI is composed of experts and other representatives designated by governments which have accepted the terms of the 'Declaration' establishing ICGFI and have pledged to make voluntary contributions, in cash or in kind, to carry out the activities of ICGFI. The functions of ICGFI are as follows: (a) To evaluate global developments in the field of food irradiation; (b) To provide a focal point of advice on the application of food irradiation to Member States and the Organization; and (c) To furnish information as required, through the Organization, to the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food, and to the Codex Alimentarius Commission. This publication contains the most up to date data on irradiation of fish, shellfish and frog legs. It is intended to assist governments in considering the authorization of this particular application of radiation processing of food and in ensuring its control in the facility and the control of irradiated food products moving in trade. It was prepared at the request of the International Consultative Group on Food Irradiation (ICGFI) in response to the increasing acceptance and application of irradiation to ensure hygienic quality of food, especially those of animal origin.

  10. Paralytic Shellfish Toxins and Cyanotoxins in the Mediterranean: New Data from Sardinia and Sicily (Italy).

    Science.gov (United States)

    Lugliè, Antonella; Giacobbe, Maria Grazia; Riccardi, Elena; Bruno, Milena; Pigozzi, Silvia; Mariani, Maria Antonietta; Satta, Cecilia Teodora; Stacca, Daniela; Bazzoni, Anna Maria; Caddeo, Tiziana; Farina, Pasqualina; Padedda, Bachisio Mario; Pulina, Silvia; Sechi, Nicola; Milandri, Anna

    2017-11-16

    Harmful algal blooms represent a severe issue worldwide. They affect ecosystem functions and related services and goods, with consequences on human health and socio-economic activities. This study reports new data on paralytic shellfish toxins (PSTs) from Sardinia and Sicily (Italy), the largest Mediterranean islands where toxic events, mainly caused by Alexandrium species (Dinophyceae), have been ascertained in mussel farms since the 2000s. The toxicity of the A. minutum, A. tamarense and A. pacificum strains, established from the isolation of vegetative cells and resting cysts, was determined by high performance liquid chromatography (HPLC). The analyses indicated the highest toxicity for A. pacificum strains (total PSTs up to 17.811 fmol cell-1). The PSTs were also assessed in a strain of A. tamarense. The results encourage further investigation to increase the knowledge of toxic species still debated in the Mediterranean. This study also reports new data on microcystins (MCs) and β-N-methylamino-L-alanine (BMAA) from a Sardinian artificial lake (Lake Bidighinzu). The presence of MCs and BMAA was assessed in natural samples and in cell cultures by enzyme-linked immunosorbent assay (ELISA). BMAA positives were found in all the analysed samples with a maximum of 17.84 µg L-1. The obtained results added further information on cyanotoxins in Mediterranean reservoirs, particularly BMAA, which have not yet been thoroughly investigated.

  11. Irradiation of fish, shellfish and frog legs. A compilation of technical data for authorization and control

    International Nuclear Information System (INIS)

    2000-06-01

    The International Consultative Group on Food Irradiation (ICGFI) was established on 9 May 1984 under the aegis of FAO, IAEA and WHO. ICGFI is composed of experts and other representatives designated by governments which have accepted the terms of the 'Declaration' establishing ICGFI and have pledged to make voluntary contributions, in cash or in kind, to carry out the activities of ICGFI. The functions of ICGFI are as follows: (a) To evaluate global developments in the field of food irradiation; (b) To provide a focal point of advice on the application of food irradiation to Member States and the Organization; and (c) To furnish information as required, through the Organization, to the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food, and to the Codex Alimentarius Commission. This publication contains the most up to date data on irradiation of fish, shellfish and frog legs. It is intended to assist governments in considering the authorization of this particular application of radiation processing of food and in ensuring its control in the facility and the control of irradiated food products moving in trade. It was prepared at the request of the International Consultative Group on Food Irradiation (ICGFI) in response to the increasing acceptance and application of irradiation to ensure hygienic quality of food, especially those of animal origin

  12. Mining the transcriptomes of four commercially important shellfish species for single nucleotide polymorphisms within biomineralization genes.

    Science.gov (United States)

    Vendrami, David L J; Shah, Abhijeet; Telesca, Luca; Hoffman, Joseph I

    2016-06-01

    Transcriptional profiling not only provides insights into patterns of gene expression, but also generates sequences that can be mined for molecular markers, which in turn can be used for population genetic studies. As part of a large-scale effort to better understand how commercially important European shellfish species may respond to ocean acidification, we therefore mined the transcriptomes of four species (the Pacific oyster Crassostrea gigas, the blue mussel Mytilus edulis, the great scallop Pecten maximus and the blunt gaper Mya truncata) for single nucleotide polymorphisms (SNPs). Illumina data for C. gigas, M. edulis and P. maximus and 454 data for M. truncata were interrogated using GATK and SWAP454 respectively to identify between 8267 and 47,159 high quality SNPs per species (total=121,053 SNPs residing within 34,716 different contigs). We then annotated the transcripts containing SNPs to reveal homology to diverse genes. Finally, as oceanic pH affects the ability of organisms to incorporate calcium carbonate, we honed in on genes implicated in the biomineralization process to identify a total of 1899 SNPs in 157 genes. These provide good candidates for biomarkers with which to study patterns of selection in natural or experimental populations. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Bioaccessibility of metals in fish, shellfish, wild game, and seaweed harvested in British Columbia, Canada.

    Science.gov (United States)

    Laird, Brian D; Chan, Hing Man

    2013-08-01

    Fish, shellfish, wild game, and seaweed are important traditional foods that are essential to the physical and cultural well-being of Indigenous peoples in Canada. The goal of this study was to measure the concentration and bioaccessibility of As, Cd, Hg, Se, Cu and Mn in 45 commonly consumed traditional foods collected by harvested by the First Nations Food, Nutrition, and Environment Study (FNFNES) from 21 First Nations communities in British Columbia, Canada, in 2008-2009. A significant and negative correlation was observed between Hg concentration and Hg bioaccessibility. Metal bioaccessibility tended to be high; median values ranging between 52% (Mn) and 83% (Cu). The notable exceptions were observed for As in wild game organs (7-19%) and rabbit meat (4%) as well as Hg in salmon eggs (10%). Results of Principal Components Analysis confirmed the unique pattern of bioaccessibility of As and Hg in traditional foods, suggesting that, unlike other metals, As and Hg bioaccessibility are not simply controlled by food digestibility under the operating conditions of the in vitro model. These data provide useful information for dietary contaminant risk assessment and intake assessments of essential trace elements. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Shellfish dredging pushes a flexible avian top predator out of a marine protected area.

    Directory of Open Access Journals (Sweden)

    Jan A van Gils

    2006-11-01

    Full Text Available There is a widespread concern about the direct and indirect effects of industrial fisheries; this concern is particularly pertinent for so-called "marine protected areas" (MPAs, which should be safeguarded by national and international law. The intertidal flats of the Dutch Wadden Sea are a State Nature Monument and are protected under the Ramsar convention and the European Union's Habitat and Birds Directives. Until 2004, the Dutch government granted permission for ~75% of the intertidal flats to be exploited by mechanical dredgers for edible cockles (Cerastoderma edule. Here we show that dredged areas belonged to the limited area of intertidal flats that were of sufficient quality for red knots (Calidris canutus islandica, a long-distance migrant molluscivore specialist, to feed. Dredging led to relatively lower settlement rates of cockles and also reduced their quality (ratio of flesh to shell. From 1998 to 2002, red knots increased gizzard mass to compensate for a gradual loss in shellfish quality, but this compensation was not sufficient and led to decreases in local survival. Therefore, the gradual destruction of the necessary intertidal resources explains both the loss of red knots from the Dutch Wadden Sea and the decline of the European wintering population. This study shows that MPAs that do not provide adequate protection from fishing may fail in their conservation objectives.

  15. Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands, East China Sea

    Science.gov (United States)

    Jiang, Tao; Xu, Yixiao; Li, Yang; Qi, Yuzao; Jiang, Tianjiu; Wu, Feng; Zhang, Fan

    2014-01-01

    A 12-month program of monitoring potentially toxic microalgae (that produce lipophilic shellfish toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identified, and D. caudata was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×102 cells/L in surface water and 1.25×102 cells/L in bottom water (cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid (OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit (20 μg OA eq./100 g meat). Ten out of fifteen wild samples (66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat (more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities (80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.

  16. Paralytic shellfish toxins, including deoxydecarbamoyl-STX, in wild-caught Tasmanian abalone (Haliotis rubra).

    Science.gov (United States)

    Harwood, D Tim; Selwood, Andrew I; van Ginkel, Roel; Waugh, Craig; McNabb, Paul S; Munday, Rex; Hay, Brenda; Thomas, Krista; Quilliam, Michael A; Malhi, Navreet; Dowsett, Natalie; McLeod, Catherine

    2014-11-01

    For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 μmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Shellfish depuration by gamma irradiation: Final report for the period October 1, 1985-September 30, 1986

    International Nuclear Information System (INIS)

    Beghian, L.; Melnick, J.

    1986-01-01

    Irradiation of live bivalve molluscs is a promising new technique to reduce the public health threats of viral and bacterial pathogens in the consumption of raw shellfish. In studies conducted within the past year, live hardshelled clams and oysters were innoculated with Simian Rotavirus SA-11, Poliovirus I, and Hepatitis-A virus and treated with gamma ray ionizing radiation from University of Lowell/DOE 800,000 Curie 60 Co source over a dose range of 0.5--10 kiloGray (50--1000 kilorad) to determine the effectiveness of the process in eliminating viral activity and thus easing the potential viral health threats associated with uncooked bivalves. Two viral strains, SA-11 and Poliovirus I, were employed as models to perfect laboratory technique and to estimate the most appropriate range of dose exposures necessary for optimal inactivation of the infectious pathogen, Hepatitis A. Post-irradiation survivorship of the oysters and quahogs was assessed over a range of exposures, and showed an exceptionally high degree of radioresistance for these molluscan species. 7 refs., 7 figs., 14 tabs

  18. Depuration of shellfish by irradiation: Final technical report, October 1, 1987--March 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Beghian, L.E.; Mallett, J.C.

    1989-01-01

    Studies by the University of Lowell Radiation Laboratory and the US National Marine Fisheries Service N.E. Laboratory in Gloucester, MA on softshelled clams (Mya arenaria) demonstrated the effectiveness of low to medium doses of Cobalt 60 source gamma irradiation in the inactivation of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Streptococcus faecalis. Post-irradiation survival and organoleptic studies when extended to hardshelled clams (Mercinaria mercenaria) and American oysters (Crassostrea virginica) showed no significant decline in consumer qualities or 6 day post irradiation survival in oysters at doses of up to 3.0 kGy. The capacities of the American oyster to sustain relatively high doses of gamma irradiation were demonstrated by 6 day post-exposure survivorship values of greater than 90% for samples receiving 3.0, 5.0 and 7.0 kGy. Initial studies of inactivation of Polio I virus and a simian rotavirus (SA-11) was conducted in both hardshelled clams and oysters. Of greatest interest was the behavior of Hepatitis A virus (HAV), in live, irradiated shellfish. The average log decrement value for HAV in oysters was calculated at 2.0 kGy. From these data it appears that doses of up to 2 kGy can be applied to: reduce or eliminate bacterial pathogens, reduce the infectivity of human viral pathogens by one or more orders of magnitude, and preserve market qualities of longevity, appearance, odor, taste and texture. 23 refs., 11 figs., 3 tabs.

  19. Shellfish depuration by gamma irradiation: Final report for the period October 1, 1985-September 30, 1986

    Energy Technology Data Exchange (ETDEWEB)

    Beghian, L.; Melnick, J.

    1986-11-01

    Irradiation of live bivalve molluscs is a promising new technique to reduce the public health threats of viral and bacterial pathogens in the consumption of raw shellfish. In studies conducted within the past year, live hardshelled clams and oysters were innoculated with Simian Rotavirus SA-11, Poliovirus I, and Hepatitis-A virus and treated with gamma ray ionizing radiation from University of Lowell/DOE 800,000 Curie /sup 60/Co source over a dose range of 0.5--10 kiloGray (50--1000 kilorad) to determine the effectiveness of the process in eliminating viral activity and thus easing the potential viral health threats associated with uncooked bivalves. Two viral strains, SA-11 and Poliovirus I, were employed as models to perfect laboratory technique and to estimate the most appropriate range of dose exposures necessary for optimal inactivation of the infectious pathogen, Hepatitis A. Post-irradiation survivorship of the oysters and quahogs was assessed over a range of exposures, and showed an exceptionally high degree of radioresistance for these molluscan species. 7 refs., 7 figs., 14 tabs.

  20. Urban bioclimatology.

    Science.gov (United States)

    Mayer, H

    1993-11-15

    This article deals with the part of urban climatology which is of particular relevance to human beings. Presented first is a summary of all human biometerologically effective complexes, as well as other factors which are relevant to urban planning and which depend on atmospheric conditions in urban structures in a direct or indirect manner. Later, methods for human biometerologically significant assessment of thermal and air pollution components of the urban climate are discussed in detail, because these components can be strongly influenced by urban planning. The application of these methods is illustrated by some results of appropriate investigations in urban areas.

  1. Participatory urbanism

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine

    2016-01-01

    cannot directly influence their structures, they can influence their contours through such leisure practices. In this chapter focus will be on how citizens’ engagement in locative leisure activities may allow them to co-create urban space. This participatory urbanism is a form of everyday democracy......Urban areas are planned structures that cannot easily be changed. Urban areas do however still afford physical spaces for various types of leisure expression and participation, from street art to parkour and from urban gaming to artistic happenings. Thus, while citizens who inhabit the urban areas...

  2. Urban lifestyle and urban biodiversity

    DEFF Research Database (Denmark)

    Petersen, L. K.; Lyytimäki, J.; Normander, B.

    2007-01-01

    This report is concerned with the relations between lifestyles of urban populations on one hand and protection of biodiversity in urban areas on the other. Urban areas are of importance for the general protection of biodiversity. In the surroundings of cities and within urban sprawls there can...... biodiversity, recreational, educational and other needs. However, uncovered and unsealed space is constantly under pressure for building and infrastructure development in the urban landscape, and the design and usages of urban green structure is a matter of differing interests and expectations. Integrating...... the green needs of urban lifestyle in the planning process does not come by itself. Nor does finding the synergies between urban lifestyle and urban biodiversity. Careful planning including stakeholder involvement is required. In this process various mapping techniques and use of indicators can be most...

  3. Arsenic, cadmium, and manganese levels in shellfish from Map Ta Phut, an industrial area in Thailand, and the potential toxic effects on human cells.

    Science.gov (United States)

    Rangkadilok, Nuchanart; Siripriwon, Pantaree; Nookabkaew, Sumontha; Suriyo, Tawit; Satayavivad, Jutamaad

    2015-01-01

    Map Ta Phut Industrial Estate is a major industrial area in Thailand for both petrochemical and heavy industries. The release of hazardous wastes and other pollutants from these industries increases the potential for contamination in foods in the surrounding area, especially farmed shellfish. This study determined the arsenic (As), cadmium (Cd), and manganese (Mn) concentrations in the edible flesh of farmed shellfish, including Perna viridis, Meretrix meretrix, and Scapharca inaequivalvis, around the Map Ta Phut area using inductively coupled plasma mass spectrometry. The results showed that shellfish samples contained high levels of total As [1.84-6.42 mg kg(-1) wet weight (ww)]. High Mn concentrations were found in P. viridis and M. meretrix, whereas S. inaequivalis contained the highest Cd. Arsenobetaine (AsB) was found to be the major As species in shellfish (>45% of total As). The in vitro cytotoxicity of these elements was evaluated using human cancer cells (T47D, A549, and Jurkat cells). An observed decrease in cell viability in T47D and Jurkat cells was mainly caused by exposure to inorganic As (iAs) or Mn but not to AsB or Cd. The combined elements (AsB+Mn+Cd) at concentrations predicted to result from the estimated daily intake of shellfish flesh by the local people showed significant cytotoxicity in T47D and Jurkat cells.

  4. Abundance and distribution of microplastics within surface sediments of a key shellfish growing region of Canada.

    Science.gov (United States)

    Kazmiruk, T N; Kazmiruk, V D; Bendell, L I

    2018-01-01

    The abundance and distribution of microplastics within 5 sediment size classes (>5000 μm, 1000-5000 μm, 250-1000 μm, 250-0.63 μm and Microplastics were found at all sampling locations indicating widespread contamination of this region with these particles. Three types of microplastics were recovered: microbeads, which occurred in the greatest number (up to 25000/kg dry sediment) and microfibers and microfragments, which were much less in number compared with microbeads and occurred in similar amounts (100-300/kg dry sediment). Microbeads were recovered primarily in the microplastics were spatially dependent with principal component analysis (PCA) indicating that 84 percent of the variation in abundance and distribution was due to the presence of high numbers of microbeads at three locations within the study region. At these sites, microbeads expressed as a percent component of the sediment by weight was similar to key geochemical components that govern trace metal behavior and availability to benthic organisms. Microbeads have been shown to accumulate metals from the aquatic environment, hence in addition to the traditional geochemical components such as silt and organic matter, microplastics also need to be considered as a sediment component that can influence trace metal geochemistry. Our findings have shown that BC's premier oyster growing region is highly contaminated with microplastics, notably microbeads. It would be prudent to assess the degree to which oysters from this region are ingesting microplastics. If so, it would have direct implications for Canada's oyster farming industry with respect to the health of the oyster and the quality of product that is being farmed and sets an example for other shellfish growing regions of the world.

  5. Ancient Clam Gardens Increased Shellfish Production: Adaptive Strategies from the Past Can Inform Food Security Today

    Science.gov (United States)

    Groesbeck, Amy S.; Rowell, Kirsten; Lepofsky, Dana; Salomon, Anne K.

    2014-01-01

    Maintaining food production while sustaining productive ecosystems is among the central challenges of our time, yet, it has been for millennia. Ancient clam gardens, intertidal rock-walled terraces constructed by humans during the late Holocene, are thought to have improved the growing conditions for clams. We tested this hypothesis by comparing the beach slope, intertidal height, and biomass and density of bivalves at replicate clam garden and non-walled clam beaches in British Columbia, Canada. We also quantified the variation in growth and survival rates of littleneck clams (Leukoma staminea) we experimentally transplanted across these two beach types. We found that clam gardens had significantly shallower slopes than non-walled beaches and greater densities of L. staminea and Saxidomus giganteus, particularly at smaller size classes. Overall, clam gardens contained 4 times as many butter clams and over twice as many littleneck clams relative to non-walled beaches. As predicted, this relationship varied as a function of intertidal height, whereby clam density and biomass tended to be greater in clam gardens compared to non-walled beaches at relatively higher intertidal heights. Transplanted juvenile L. staminea grew 1.7 times faster and smaller size classes were more likely to survive in clam gardens than non-walled beaches, specifically at the top and bottom of beaches. Consequently, we provide strong evidence that ancient clam gardens likely increased clam productivity by altering the slope of soft-sediment beaches, expanding optimal intertidal clam habitat, thereby enhancing growing conditions for clams. These results reveal how ancient shellfish aquaculture practices may have supported food security strategies in the past and provide insight into tools for the conservation, management, and governance of intertidal seascapes today. PMID:24618748

  6. Tracing the origin of paralytic shellfish toxins in scallop Patinopecten yessoensis in the northern Yellow Sea.

    Science.gov (United States)

    Chen, Jian-Hua; Yu, Ren-Cheng; Gao, Yan; Kong, Fan-Zhou; Wang, Yun-Feng; Zhang, Qing-Chun; Kang, Zhen-Jun; Yan, Tian; Zhou, Ming-Jiang

    2013-01-01

    Some dinoflagellate species within the genera Alexandrium, Gymnodinium and Pyrodinium are well-known producers of paralytic shellfish toxins (PST), which led to many poisoning incidents around the world. In the northern Yellow Sea, an important mariculture zone for scallop Patinopecten yessoensis, PST have been frequently detected from scallops. However, there is little knowledge concerning PST-producing microalgae in this region so far. In cruises carried out in 2011 and 2012, scallop and phytoplankton samples were collected from the northern Yellow Sea. PST were detected from scallops by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Toxin content and profile were remarkably different among the four tissues, i.e. viscera, adductor muscle, mantle and gonad, suggesting apparent toxin transfer and transformation in scallops. Viscera always had the highest content of PST dominated by low-potency N-sulfocarbamoyl toxins C1 and C2, which closely resembled the toxin profiles of net-concentrated phytoplankton samples in spring. Based on the morphological features, cells of Alexandrium spp. in net-concentrated phytoplankton samples were picked out and a partial sequence of the large subunit ribosomal RNA gene (LSU rDNA) was amplified using a single-cell polymerase chain reaction (PCR) method. Cells of both toxic A. tamarense species complex and non-toxic A. affine were identified from the phytoplankton samples based on the partial LSU rDNA sequence information. According to these findings, it is implied that A. tamarense species complex is the major toxic species related to PST contamination in scallops of the northern Yellow Sea. The presence of both toxic and non-toxic Alexandrium spp. in this region requires for a species-specific method to monitor the distribution and dynamics of A. tamarense species complex.

  7. Matrix effect on paralytic shellfish toxins quantification and toxicity estimation in mussels exposed to Gymnodinium catenatum.

    Science.gov (United States)

    Botelho, M J; Vale, C; Mota, A M; Rodrigues, S M; Costa, P R; Simões Gonçalves, M L S

    2010-12-01

    Paralytic shellfish toxins were quantified in whole tissues of the mussel Mytilus galloprovincialis exposed to blooms of the dinoflagellate Gymnodinium catenatum in Portuguese coastal waters. A validated liquid chromatography method with fluorescence detection, involving pre-chromatographic oxidation was used to quantify carbamoyl, N-sulfocarbamoyl and decarbamoyl toxins. In order to test for any matrix effect in the quantification of those toxins, concentrations obtained from solvent and matrix matched calibration curves were compared. A suppression of the fluorescence signal was observed in mussel extract or fraction in comparison to solvent for the compounds dcGTX2 + 3, GTX2 + 3 and GTX1 + 4, while an enhancement was found for C1 + 2, dcSTX, STX, B1, dcNEO and NEO. These results showed that a matrix effect varies among compounds. The difference of concentrations between solvent and matrix matched calibration curves for C1 + 2 (median = 421 ng g⁻¹) exceeded largely the values for the other quantified compounds (0.09-58 ng g⁻¹). Those differences were converted into toxicity differences, using Oshima toxicity equivalence factors. The compounds C1 + 2 and dcNEO were the major contributors to the differences of total toxicity in the mussel samples. The differences of total toxicity were calculated in ten mussel samples collected during a 10-week blooming period in Portuguese coastal lagoon. Values varied between 53 and 218 µg STX equivalents kg⁻¹. The positive differences mean that the estimated toxicity using solvent calibration curves exceed the values taking into account the matrix. For the toxicity interval 200-800 µg STX equivalents kg⁻¹ an increase was found between 44 and 28%.

  8. Implementation of marine spatial planning in shellfish aquaculture management: modeling studies in a Norwegian fjord.

    Science.gov (United States)

    Filgueira, Ramon; Grant, Jon; Strand, Øivind

    2014-06-01

    Shellfish carrying capacity is determined by the interaction of a cultured species with its ecosystem, which is strongly influenced by hydrodynamics. Water circulation controls the exchange of matter between farms and the adjacent areas, which in turn establishes the nutrient supply that supports phytoplankton populations. The complexity of water circulation makes necessary the use of hydrodynamic models with detailed spatial resolution in carrying capacity estimations. This detailed spatial resolution also allows for the study of processes that depend on specific spatial arrangements, e.g., the most suitable location to place farms, which is crucial for marine spatial planning, and consequently for decision support systems. In the present study, a fully spatial physical-biogeochemical model has been combined with scenario building and optimization techniques as a proof of concept of the use of ecosystem modeling as an objective tool to inform marine spatial planning. The object of this exercise was to generate objective knowledge based on an ecosystem approach to establish new mussel aquaculture areas in a Norwegian fjord. Scenario building was used to determine the best location of a pump that can be used to bring nutrient-rich deep waters to the euphotic layer, increasing primary production, and consequently, carrying capacity for mussel cultivation. In addition, an optimization tool, parameter estimation (PEST), was applied to the optimal location and mussel standing stock biomass that maximize production, according to a preestablished carrying capacity criterion. Optimization tools allow us to make rational and transparent decisions to solve a well-defined question, decisions that are essential for policy makers. The outcomes of combining ecosystem models with scenario building and optimization facilitate planning based on an ecosystem approach, highlighting the capabilities of ecosystem modeling as a tool for marine spatial planning.

  9. Phylogeography of cylindrospermopsin and paralytic shellfish toxin-producing nostocales cyanobacteria from mediterranean europe (Spain).

    Science.gov (United States)

    Cirés, Samuel; Wörmer, Lars; Ballot, Andreas; Agha, Ramsy; Wiedner, Claudia; Velázquez, David; Casero, María Cristina; Quesada, Antonio

    2014-02-01

    Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A. mendotae, and A. planctonica), Aphanizomenon (Aphanizomenon gracile, A. ovalisporum), and Cylindrospermopsis raciborskii were isolated from 14 freshwater bodies in Spain and polyphasically analyzed for their phylogeography, cyanotoxin production, and the presence of cyanotoxin biosynthesis genes. The potent cytotoxin cylindrospermopsin (CYN) was produced by all 6 Aphanizomenon ovalisporum strains at high levels (5.7 to 9.1 μg CYN mg(-1) [dry weight]) with low variation between strains (1.5 to 3.9-fold) and a marked extracellular release (19 to 41% dissolved CYN) during exponential growth. Paralytic shellfish poisoning (PSP) neurotoxins (saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin) were detected in 2 Aphanizomenon gracile strains, both containing the sxtA gene. This gene was also amplified in non-PSP toxin-producing Aphanizomenon gracile and Aphanizomenon ovalisporum. Phylogenetic analyses supported the species identification and confirmed the high similarity of Spanish Anabaena and Aphanizomenon strains with other European strains. In contrast, Cylindrospermopsis raciborskii from Spain grouped together with American strains and was clearly separate from the rest of the European strains, raising questions about the current assumptions of the phylogeography and spreading routes of C. raciborskii. The present study confirms that the nostocalean genus Aphanizomenon is a major source of CYN and PSP toxins in Europe and demonstrates the presence of the sxtA gene in CYN-producing Aphanizomenon ovalisporum.

  10. Urban physics

    NARCIS (Netherlands)

    Blocken, B.J.E.

    2012-01-01

    Urban Physics is the multiscale and interdisciplinary research area dealing with physical processes in urban environments that influence our everyday health, comfort and productivity. It involves disciplines ranging from mesoscale meteorology to human thermophysiology. The introductory lecture

  11. Urban Times

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2017-01-01

    This is a proposed special issue with six thematic articles by different contributors on 'urban times' edited by me.......This is a proposed special issue with six thematic articles by different contributors on 'urban times' edited by me....

  12. Urban streets

    NARCIS (Netherlands)

    Schönfeld, von Kim Carlotta; Bertolini, Luca

    2017-01-01

    Today's urban streets are usually planned for purposes of mobility: pedestrians, as well as a variety of vehicles such as cars, trucks, and sometimes bicycles, are usually factored into an urban street plan. However, urban streets are also increasingly recognized as public spaces, accommodating

  13. Screening for the presence of lipophilic marine biotoxins in shellfish samples using the neuro-2a bioassay.

    Science.gov (United States)

    Bodero, Marcia; Bovee, Toine F H; Wang, Si; Hoogenboom, Ron L A P; Klijnstra, Mirjam D; Portier, Liza; Hendriksen, Peter J M; Gerssen, Arjen

    2018-02-01

    The neuro-2a bioassay is considered as one of the most promising cell-based in vitro bioassays for the broad screening of seafood products for the presence of marine biotoxins. The neuro-2a assay has been shown to detect a wide array of toxins like paralytic shellfish poisons (PSPs), ciguatoxins, and also lipophilic marine biotoxins (LMBs). However, the neuro-2a assay is rarely used for routine testing of samples due to matrix effects that, for example, lead to false positives when testing for LMBs. As a result there are only limited data on validation and evaluation of its performance on real samples. In the present study, the standard extraction procedure for LMBs was adjusted by introducing an additional clean-up step with n-hexane. Recovery losses due to this extra step were less than 10%. This wash step was a crucial addition in order to eliminate false-positive outcomes due to matrix effects. Next, the applicability of this assay was assessed by testing a broad range of shellfish samples contaminated with various LMBs, including diarrhetic shellfish toxins/poisons (DSPs). For comparison, the samples were also analysed by LC-MS/MS. Standards of all regulated LMBs were tested, including analogues of some of these toxins. The neuro-2a cells showed good sensitivity towards all compounds. Extracts of 87 samples, both blank and contaminated with various toxins, were tested. The neuro-2a outcomes were in line with those of LC-MS/MS analysis and support the applicability of this assay for the screening of samples for LMBs. However, for use in a daily routine setting, the test might be further improved and we discuss several recommended modifications which should be considered before a full validation is carried out.

  14. Temporal and Spatial Variation in the Abundance of Total and Pathogenic Vibrio parahaemolyticus in Shellfish in China.

    Directory of Open Access Journals (Sweden)

    Haihong Han

    Full Text Available We investigated the abundance of total and pathogenic Vibrio parahaemolyticus in shellfish sampled from four provinces in China during May 2013 and March 2014 using the most probable number-polymerase chain reaction (MPN-PCR method. Total V. parahaemolyticus was detected in 67.7% of 496 samples. A total of 38.1% and 10.1% of samples exceeded 1,000 MPN g(-1 and 10,000 MPN g(-1, respectively. V. parahaemolyticus densities followed a seasonal and geographical trend, with Guangxi and Sichuan shellfish possessing total V. parahaemolyticus levels that were 100-fold higher than those of the Liaoning and Shandong regions. Moreover, the levels of V. parahaemolyticus were at least 10-fold higher in the summer and autumn than in the cooler seasons. Pathogenic V. parahaemolyticus levels were generally lower than total V. parahaemolyticus levels by several log units and tended to be high in samples contaminated with high total V. parahaemolyticus levels. The aqua farms had a lower prevalence but higher abundance of total V. parahaemolyticus compared to retail markets. The catering markets showed the lowest levels of total V. parahaemolyticus, but 20.0% of samples exceeded 1,000 MPN g(-1. The levels of both total and pathogenic V. parahaemolyticus in oysters were higher than in clams. The log-transformed abundance of V. parahaemolyticus was significantly correlated with both water temperature and air temperature but not water salinity. These results provide baseline contamination data of V. parahaemolyticus in shellfish in China, which can be applied to local risk assessments to prioritize risk control to key sectors and evaluate the effectiveness of future control measures.

  15. Regional acidification trends in Florida shellfish estuaries: A 20+ year look at pH, oxygen, temperature, and salinity

    Science.gov (United States)

    Robbins, Lisa L.; Lisle, John T.

    2018-01-01

    Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

  16. Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were significantly lower in claims. Concentrations of Vibrio cholerae rose by approximately 1 log in oysters stored as shellstock after 7 days at 2 degrees C, and Lac+ vibrios increased 2 logs at 8 degrees C. Total counts of bacteria, fungi, coliforms, fecal streptococci, Aeromonas hydrophila, and clostridia were significantly higher in shucked oysters than in those stored as shellstock. Fecal coliforms were statistically the same, but V. cholerae, Vibrio parahaemolyticus, and the Lac+ vibrios were higher in oysters stored as shellstock. The concentrations of all microbial groups were higher in fully processed oysters than in shucked meats, with the exception of the vibrios, which showed no significant difference among the treatments. The results showed that although traditional methods of storing shellfish resulted in an overall increase in the microbial load, vibrio levels increased only in oysters stored as shellstock. Although fecal coliform and total bacterial counts did not correlate with those for vibrios in fresh oysters, strong correlations were observed in oysters stored for 7 days, suggesting that these indicators may be useful in monitoring oyster quality when meats are stored for a limited time as shellstock.

  17. Regional acidification trends in Florida shellfish estuaries: A 20+ year look at pH, oxygen, temperature and salinity

    Science.gov (United States)

    Robbins, Lisa L.; Lisle, John T.

    2018-01-01

    Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

  18. Differential Mobility Spectrometry for Improved Selectivity in Hydrophilic Interaction Liquid Chromatography-Tandem Mass Spectrometry Analysis of Paralytic Shellfish Toxins

    Science.gov (United States)

    Beach, Daniel G.

    2017-08-01

    Paralytic shellfish toxins (PSTs) are neurotoxins produced by dinoflagellates and cyanobacteria that cause paralytic shellfish poisoning in humans. PST quantitation by LC-MS is challenging because of their high polarity, lability as gas-phase ions, and large number of potentially interfering analogues. Differential mobility spectrometry (DMS) has the potential to improve the performance of LC-MS methods for PSTs in terms of selectivity and limits of detection. This work describes a comprehensive investigation of the separation of 16 regulated PSTs by DMS and the development of highly selective LC-DMS-MS methods for PST quantitation. The effects of all DMS parameters on the separation of PSTs from one another were first investigated in detail. The labile nature of 11α-gonyautoxin epimers gave unique insight into fragmentation of labile analytes before, during, and after the DMS analyzer. Two sets of DMS parameters were identified that either optimized the resolution of PSTs from one another or transmitted them at a limited number of compensation voltage (CV) values corresponding to structural subclasses. These were used to develop multidimensional LC-DMS-MS/MS methods using existing HILIC-MS/MS parameters. In both cases, improved selectivity was observed when using DMS, and the quantitative capabilities of a rapid UPLC-DMS-MS/MS method were evaluated. Limits of detection of the developed method were similar to those without DMS, and differences were highly analyte-dependant. Analysis of shellfish matrix reference materials showed good agreement with established methods. The developed methods will be useful in cases where specific matrix interferences are encountered in the LC-MS/MS analysis of PSTs in complex biological samples.

  19. Development of a toxicity model for paralytic shellfish toxins in mussel: uptake and release of toxins in Green Bay mussel

    International Nuclear Information System (INIS)

    Tabbada, Rhett Simon DC.; Ranada, Ma. Llorina O.; De Leon, Aileen L.; Bulos, Adelina M.; Sta, Maria; Efren, J.; De Vera, Azucena; Balagtas, Angelina; Sombrito, Elvira Z.

    2009-01-01

    In view of the expressed need to study shellfish toxicity and elucidate the kinetics of saxitoxin in green mussels Perna viridis), uptake/depuration rates of saxitoxin were studied in Juag Lagoon, Sorsogon and Sorsogon Bay. Both areas experience recurring blooms of Pyrodinium bahamanse var compressum (PbC) making them excellent study sites. Two sampling stations were selected, to which, mussels were introduced. Algal cell density and mussel toxicity were measured by receptor binding assay (RBA) and high performance liquid chromatography (HPLC) from May to December 2007. During this period, two bloom events occurred, wherein, a decrease in cell density by two orders of magnitude (30,000 to 600 cells·1 +1 ) caused an order of magnitude decrease in toxicity (600 to 30 μg STX eq./100 g shellfish meat). A time lag between peaks of cell density and the corresponding toxicity was revealed. Vegetative cells were present throughout the sampling period, and a uniform horizontal and vertical distribution of cells was observed between the stations. Cell densities were significantly correlated with both RBA and HPLC estimates of STX content in mussels (Pearson r values of 0.7486 and 0.4325 for RBA and HPLC, respectively). In Sorsogon Bay, six sampling stations were also chosen, from which, water and mussels were being collected. Preliminary data showed that the cellular toxin content was primarily STX, making up to 90-100% of total toxin quantified. The average toxicity was estimated at 52.81fmol/cell. The effect of physiological factors to overall shellfish toxicity, though not directly characterized, may be deduced from these studies. (author)

  20. Urban architecture in urban renewal

    DEFF Research Database (Denmark)

    Holmgren, Steen; Svensson, Ole

    2001-01-01

    and without obvious architectural value. These issues raise pertinent questions: what urban architectural problems and qualities exist in the complex, inner suburbs? What differences exist between professionals' and residents' perceptions and assessments of urban architecture? How can a shared language...

  1. Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine: The HAB Index

    Science.gov (United States)

    Anderson, Donald M.; Couture, Darcie A.; Kleindinst, Judith L.; Keafer, Bruce A.; McGillicuddy, Dennis J., Jr.; Martin, Jennifer L.; Richlen, Mindy L.; Hickey, J. Michael; Solow, Andrew R.

    2014-05-01

    A major goal in harmful algal bloom (HAB) research has been to identify mechanisms underlying interannual variability in bloom magnitude and impact. Here the focus is on variability in Alexandrium fundyense blooms and paralytic shellfish poisoning (PSP) toxicity in Maine, USA, over 34 years (1978-2011). The Maine coastline was divided into two regions - eastern and western Maine, and within those two regions, three measures of PSP toxicity (the percent of stations showing detectable toxicity over the year, the cumulative amount of toxicity per station measured in all shellfish (mussel) samples during that year, and the duration of measurable toxicity) were examined for each year in the time series. These metrics were combined into a simple HAB Index that provides a single measure of annual toxin severity across each region. The three toxin metrics, as well as the HAB Index that integrates them, reveal significant variability in overall toxicity between individual years as well as long-term, decadal patterns or regimes. Based on different conceptual models of the system, we considered three trend formulations to characterize the long-term patterns in the Index - a three-phase (mean-shift) model, a linear two-phase model, and a pulse-decline model. The first represents a “regime shift” or multiple equilibria formulation as might occur with alternating periods of sustained high and low cyst abundance or favorable and unfavorable growth conditions, the second depicts a scenario of more gradual transitions in cyst abundance or growth conditions of vegetative cells, and the third characterizes a ”sawtooth” pattern in which upward shifts in toxicity are associated with major cyst recruitment events, followed by a gradual but continuous decline until the next pulse. The fitted models were compared using both residual sum of squares and Akaike's Information Criterion. There were some differences between model fits, but none consistently gave a better fit than the

  2. Matrix effect and correction by standard addition in quantitative liquid chromatographic-mass spectrometric analysis of diarrhetic shellfish poisoning toxins.

    Science.gov (United States)

    Ito, Shinya; Tsukada, Katsuo

    2002-01-11

    An evaluation of the feasibility of liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure ionization was made for quantitation of four diarrhetic shellfish poisoning toxins, okadaic acid, dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops. When LC-MS was applied to the analysis of scallop extracts, large signal suppressions were observed due to coeluting substances from the column. To compensate for these matrix signal suppressions, the standard addition method was applied. First, the sample was analyzed and then the sample involving the addition of calibration standards is analyzed. Although this method requires two LC-MS runs per analysis, effective correction of quantitative errors was found.

  3. Optimization of PMAxx pretreatment to distinguish between human norovirus with intact and altered capsids in shellfish and sewage samples.

    Science.gov (United States)

    Randazzo, Walter; Khezri, Mohammad; Ollivier, Joanna; Le Guyader, Françoise S; Rodríguez-Díaz, Jesús; Aznar, Rosa; Sánchez, Gloria

    2018-02-02

    Shellfish contamination by human noroviruses (HuNoVs) is a serious health and economic problem. Recently an ISO procedure based on RT-qPCR for the quantitative detection of HuNoVs in shellfish has been issued, but these procedures cannot discriminate between inactivated and potentially infectious viruses. The aim of the present study was to optimize a pretreatment using PMAxx to better discriminate between intact and heat-treated HuNoVs in shellfish and sewage. To this end, the optimal conditions (30min incubation with 100μM of PMAxx and 0.5% of Triton, and double photoactivation) were applied to mussels, oysters and cockles artificially inoculated with thermally-inactivated (99°C for 5min) HuNoV GI and GII. This pretreatment reduced the signal of thermally-inactivated HuNoV GI in cockles and HuNoV GII in mussels by >3 log. Additionally, this pretreatment reduced the signal of thermally-inactivated HuNoV GI and GII between 1 and 1.5 log in oysters. Thermal inactivation of HuNoV GI and GII in PBS, sewage and bioaccumulated oysters was also evaluated by the PMAxx-Triton pretreatment. Results showed significant differences between reductions observed in the control and PMAxx-treated samples in PBS following treatment at 72 and 95°C for 15min. In sewage, the RT-qPCR signal of HuNoV GI was completely removed by the PMAxx pretreatment after heating at 72 and 95°C, while the RT-qPCR signal for HuNoV GII was completely eliminated only at 95°C. Finally, the PMAxx-Triton pretreatment was applied to naturally contaminated sewage and oysters, resulting in most of the HuNoV genomes quantified in sewage and oyster samples (12 out of 17) corresponding to undamaged capsids. Although this procedure may still overestimate infectivity, the PMAxx-Triton pretreatment represents a step forward to better interpret the quantification of intact HuNoVs in complex matrices, such as sewage and shellfish, and it could certainly be included in the procedures based on RT-qPCR. Copyright

  4. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban design and architecture are increasingly used as material and affective strategies for setting the scene, for manipulation and the production of urban life: The orchestration of atmospheres, the framing and staging of urban actions, the programming for contemplation, involvement, play......, experience and consumption are all strategic design tools applied by planners and architects. Whereas urban design in former modernist planning served merely functional or political means, urban design has increasingly become an aesthetical mediator of ideologies embedded in the urban field of life forces....... Under these circumstances affective aesthetics operate strategically within the urban field of interests, capital flows and desires of the social. This ‘affective urbanism’ (Anderson & Holden 2008) is linked to a society influenced by new kinds of information flows, where culture is mediated and enacted...

  5. New York Bight sub-estuaries Study following Hurricane Sandy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Polychlorinated biphenyls (PCBs), organochlorine pesticides, polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs,...

  6. Concentrations of 210Po in fish and shellfish from southern region of Japan and evaluation of 210Po intake from seafood for Japanese people

    International Nuclear Information System (INIS)

    Momoshima, N.; Sugihara, S.; Nakao, H.

    2012-01-01

    Concentrations of 210 Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of 210 Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and 210 Po was analyzed. The phytoplankton occupied only 4.4% of 210 Po in seawater and a large fraction of 210 Po was observed in the particulate form. (orig.)

  7. [Modeling the occurrence of shellfish poisoning outbreaks caused by Gymnodinium catenatum (Dinophyceae) through electromagnetic signal triggering].

    Science.gov (United States)

    Vale, Pulo

    2014-01-01

    Accumulation of paralytic shellfish poisoning toxins (PSTs) in bivalves attributed to Gymnodinium catenatum blooms at the NW Portuguese coast was previously associated with periods of low solar activity (measured by the radio flux [R]), or low geomagnetic A(a) index. It was also observed that reduction of R preceded the occurrence of toxin accumulation, while A(a) index increase could be related to its absence during periods of low activity. For modeling toxin accumulation, the monthly decrease in R was studied along the decade 2003-2012. A match that helped explaining the highly toxic years of 2007 and 2008 was obtained by plotting the formula: ΔR = (R(n-1) - R(n))/(R(n) - 65)2, where 65 represented the lowest radio activity known to date. The complex denominator was required to take into account the sunspot cycle. A 1-2 month lag was observed between maximal relative decline and maximal PSTs accumulation. PSTs in bivalves from the Portuguese south coast were related with natural electromagnetic cycles for the first time, and were not statistically associated with low R. A statistically significant association with low A(a) index also was not achieved, due to the low number of occurrences, although the 25-75 percentile was restricted to low Aa indexes in a similar way to that found for the NW coast. PSTs accumulation outside solar minima could be triggered by a steep decline in the A(a) index (ΔA), but no lag was observed in this case. While ΔR amplitude helped explaining the highly toxic years of 2007 and 2008 at the NW coast, the amplitude of ΔA was not related to the severity of the accumulation. Other kind of local electromagnetic signaling was investigated resorting to the occurrence of seismologic phenomena, because these events can trigger electric activities. No statistical association was found between seism number or magnitude and PSTs at the south coast, located near the boundary between the African and Eurasian plates, and marked by moderate

  8. Distribution and sources of n-alkanes and polycyclic aromatic hydrocarbons in shellfish of the Egyptian Red Sea coast

    Directory of Open Access Journals (Sweden)

    Ahmed El Nemr

    2016-06-01

    Full Text Available Aromatic hydrocarbons and n-alkanes were analyzed in shellfish collected from 13 different sites along the Egyptian Red Sea coast. All samples were analyzed for n-alkanes (C8–C40 and polycyclic aromatic hydrocarbons (EPA list of PAHs. n-Alkanes in shellfish samples from 13 locations were found to be in the range of 71.0–701.1 ng/g with a mean value of 242.2 ± 192.1 ng/g dry wt. Different indices were calculated for the n-alkanes to assess their sources. These were carbon preference index (CPI, average chain length (ACL, terrigenous/aquatic ratio (TAR, natural n-alkane ratio (NAR and proxy ratio (Paq. Most of the collected samples of n-alkanes were discovered to be from natural sources. Aromatic hydrocarbons (16 PAHs from 13 sites varied between 1.3 and 160.9 ng/g with an average of 47.9 ± 45.5 ng/g dry wt. Benzo(apyrine (BaP, a cancer risk assessment, was calculated for the PAHs and resulted in ranges between 0.08 and 4.47 with an average of 1.25 ng/g dry wt.

  9. Particle size fractionation of paralytic shellfish toxins (PSTs): seasonal distribution and bacterial production in the St Lawrence estuary, Canada.

    Science.gov (United States)

    Michaud, S; Levasseur, M; Doucette, G; Cantin, G

    2002-10-01

    We determined the seasonal distribution of paralytic shellfish toxins (PSTs) and PST producing bacteria in > 15, 5-15, and 0.22-5 microm size fractions in the St Lawrence. We also measured PSTs in a local population of Mytilus edulis. PST concentrations were determined in each size fraction and in laboratory incubations of sub-samples by high performance liquid chromatography (HPLC), including the rigorous elimination of suspected toxin 'imposter' peaks. Mussel toxin levels were determined by mouse bioassay and HPLC. PSTs were detected in all size fractions during the summer sampling season, with 47% of the water column toxin levels associated with particles smaller than Alexandrium tamarense ( 15 microm size fraction, we estimated that as much as 92% of PSTs could be associated with particles other than A. tamarense. Our results stress the importance of taking into account the potential presence of PSTs in size fractions other than that containing the known algal producer when attempting to model shellfish intoxication, especially during years of low cell abundance. Finally, our HPLC results confirmed the presence of bacteria capable of autonomous PST production in the St Lawrence as well as demonstrating their regular presence and apparent diversity in the plankton. Copyright 2002 Elsevier Science Ltd.

  10. Distribution of heavy metals in internal organs and tissues of Korean molluscan shellfish and potential risk to human health.

    Science.gov (United States)

    Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kim, Poong Ho; Lee, Tae Seek; Kim, Ji Hoe

    2015-09-01

    Molluscan shellfish (gastropods and bivalves) were collected from major fish markets on the Korean coast and analyzed for mercury by direct Hg analyzer and for other metals, such as cadmium, lead, chromium, silver, nickel, copper and zinc, using inductively coupled plasma mass spectrometry. Distribution of heavy metals in muscles, internal organs and whole tissues were determined and a potential risk assessment was conducted to evaluate their hazard for human consumption. Heavy metals were accumulated significantly higher (P hazardous metals (Cd, Pb, and Hg) in all internal-organ samples were above the regulatory limit of Korea and the mean level in whole tissue samples of the selected gastropod species, bay scallop and comb pen shell, exceeded the limit (except in a few cases). The sum of the estimated dietary intake of Cd, Pb and Hg for each part of all tested species accounted for 1.59-16.94, 0.02-0.36, and 0.07-0.16% respectively, of the provisional tolerable daily intake adopted by the Joint FAO/WHO Expert Committee on Food Additives. The hazard index for each part of gastropods and bivalves was below 1.0, however, the maximum HI for internal organs of all analysed species was quite high (0.71). These results suggest that consumption of flesh after removing the internal organs of some molluscan shellfish (all gastropod species, bay scallop and comb pen shell) is a suitable way for reducing Cd exposure.

  11. Two quantitative real-time PCR assays for the detection of penaeid shrimp and blue crab, crustacean shellfish allergens.

    Science.gov (United States)

    Eischeid, Anne C; Kim, Bang-hyun; Kasko, Sasha M

    2013-06-19

    Food allergen detection methods must be able to specifically detect minute quantities of an allergenic food in a complex food matrix. One technique that can be used is real-time PCR. For the work described here, real-time PCR assays were developed to detect penaeid shrimp and blue crab, crustacean shellfish allergens. The method was tested using shrimp meat and crab meat spiked into several types of foods, including canned soups, deli foods, meat, seafood, and prepared seafood products. Foods were spiked with either shrimp or crab at levels ranging from 0.1 to 10⁶ parts per million (ppm) and analyzed either raw or cooked by a variety of methods. Real-time PCR data were used to generate linear standard curves, and assays were evaluated with respect to linear range and reaction efficiency. Results indicate that both assays performed well in a variety of food types. High reaction efficiencies were achieved across a linear range of 6-8 orders of magnitude. Limits of detection were generally between 0.1 and 1 ppm. Cooking methods used to simulate thermal processing of foods had little effect on assay performance. This work demonstrates that real-time PCR can be a valuable tool in the detection of crustacean shellfish.

  12. The Seasonality of Fecal Coliform Bacteria Pollution and its Influence on Closures of Shellfish Harvesting Areas in Mississippi Sound

    Directory of Open Access Journals (Sweden)

    Paul B. Tchounwou

    2005-08-01

    Full Text Available Runoff from agricultural lands and farm animal feedlots is one of the major sources of fecal coliforms in surface waters, and fecal coliform (FC bacteria concentrations tend to vary with season because of seasonal variations in climatic factors. However, El Niño -Southern Oscillation (ENSO events may affect the extent and patterns of seasonality in FC levels in coastal waters. Water quality monitoring data for shellfish management collected during El Niño (1990, 1992, 1997, and La Niña (1999, 2000 years were analyzed to evaluate the extent to which these events influenced Pearl River stage, and bacterial levels, water temperature, and salinity in the western part of Mississippi Sound. Models to predict FC levels in relation to various environmental factors were also developed. In 1990, 1992 and 1997, FC geometric mean counts peaked in late winter (January/February reaching 120 MPN (February 1990, 165 MPN (January 1992, and 86 MPN (January 1997, and then decreased considerably during spring and summer (1.2 – 19 MPN. Thereafter, FC abundance increased slightly in fall and early winter (1.9 – 24 MPN. Fecal coliform abundance during the 2000 La Niña year was much lower (1.0 – 10.3 MPN than in 1992 (1.2 – 165 MPN, and showed no seasonal pattern from January to August, perhaps due to the relative scarcity of rainfall in 2000. In 1995 (ENSO neutral year, peak geometric mean FC count (46 MPN was lower than during El Niño years and occurred in early spring (March. The seasonal and between year variations in FC levels determined the number of days during which the conditionally approved shellfish growing area was opened for harvesting shellfish. For example, from January to April 1997, the area was not opened for shellfish harvesting, whereas in 2000, the number of days during which the area was opened ranged from 6 - 27 (January to April to 24 - 26 (October to December

  13. Near-Real-Time Surveillance of Illnesses Related to Shellfish Consumption in British Columbia: Analysis of Poison Center Data.

    Science.gov (United States)

    Wan, Victoria; McIntyre, Lorraine; Kent, Debra; Leong, Dennis; Henderson, Sarah B

    2018-02-23

    Data from poison centers have the potential to be valuable for public health surveillance of long-term trends, short-term aberrations from those trends, and poisonings occurring in near-real-time. This information can enable long-term prevention via programs and policies and short-term control via immediate public health response. Over the past decade, there has been an increasing use of poison control data for surveillance in the United States, Europe, and New Zealand, but this resource still remains widely underused. The British Columbia (BC) Drug and Poison Information Centre (DPIC) is one of five such services in Canada, and it is the only one nested within a public health agency. This study aimed to demonstrate how DPIC data are used for routine public health surveillance in near-real-time using the case study of its alerting system for illness related to consumption of shellfish (ASIRCS). Every hour, a connection is opened between the WBM software Visual Dotlab Enterprise, which holds the DPIC database, and the R statistical computing environment. This platform is used to extract, clean, and merge all necessary raw data tables into a single data file. ASIRCS automatically and retrospectively scans a 24-hour window within the data file for new cases related to illnesses from shellfish consumption. Detected cases are queried using a list of attributes: the caller location, exposure type, reasons for the exposure, and a list of keywords searched in the clinical notes. The alert generates a report that is tailored to the needs of food safety specialists, who then assess and respond to detected cases. The ASIRCS system alerted on 79 cases between January 2015 and December 2016, and retrospective analysis found 11 cases that were missed. All cases were reviewed by food safety specialists, and 58% (46/79) were referred to designated regional health authority contacts for follow-up. Of the 42% (33/79) cases that were not referred to health authorities, some were

  14. CRISTISPIRA IN NORTH AMERICAN SHELLFISH. A NOTE ON A SPIRILLUM FOUND IN OYSTERS.

    Science.gov (United States)

    Noguchi, H

    1921-08-31

    Ten varieties of North American shellfish were examined for the occurrence of Cristispira in their styles. A cristispira was found in various numbers in Ostrea virginiana, Venus mercenaria, and Modiola modiolus, but none in Ensis americana, Mya arenaria, Mactra solidissima, Pecten irradians, Mytilus edulis, Fulgur canaliculatus, or Nassa obsoleta. Of 298 oysters, only 128 showed the crystalline styles, in which cristispiras were present in 99. Active cristispiras were found in 59 styles only and degenerated forms in the remaining 40. In 110 clams (Venus mercenaria) 70 styles were found, and only 8 of these contained cristispiras; 5 yielded active and the other 3 degenerated cristispiras. In 97 modiolas there were 73 styles, only 4 of which contained cristispiras. The physical properties of the crystalline styles of these shellfish varied considerably. The styles of the oysters were moderately soft, and when exposed to the air or mixed with sea water they underwent liquefaction, forming a clear, viscid material. The styles from clams and modiolas were opaque and were more firm, not easily crushed even in a mortar. The styles of the scallops were the most solid of all the styles examined. It happened that the softer the styles, the more frequent was the occurrence of the cristispira; in fact, no cristispira was detected in styles other than those of oysters, clams, and modiolas, of which oysters had the softest styles and the largest percentage of cristispira invasion. The following observations were made regarding the structure of the cristispira found in oysters. The body is a long, flexible cylinder, with blunt extremities, towards which the diameter gradually diminishes. In motion the body rapidly stretches and contracts, forming in the contracted state several serpentine undulations. A membranous appendage (Gross' crista) winds about the body throughout its entire length. The inner margin is in connection with the body, the outer margin is free and is distinctly

  15. Urban blight and urban redesign

    OpenAIRE

    Zsilincsar, Walter

    2018-01-01

    The phenomenon of urban blight dates back to the 19th century when industrialisation starting in Europe and North America initiated an uncontrolled urban growth in combination with strong demand in cheap an quickly constructed housing. Ghettoisation of mainly the working-class population and other “marginal groups” were the consequence together with a constant decay of single buildings, whole blocks and quarters. These general aspects of urban blight with its additional facettes or aspects re...

  16. Clean and safe supply of fish and shellfish to clear the HACCP regulation by use of clean and cold deep ocean water in Rausu, Hokkaido, Japan

    Science.gov (United States)

    Mac Takahashi, Masayuki; Yamashita, Kazunori

    2005-07-01

    For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is essential. According to HACCP (Hazard Analysis and Critical Control Points), it is important to meet such requirement by keeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water (DOW) characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly for salmon, cod, and sea urchin in Town ‘Rausu’ in Hokkaido, Japan. DOW below 2.9’C of an amount of nearly 5 000m3 is planned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land. DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in clean and cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOW are also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of 2005.

  17. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different...

  18. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different ...

  19. Urban Forests

    Science.gov (United States)

    David Nowak

    2016-01-01

    Urban forests (and trees) constitute the second forest resource considered in this report. We specifically emphasize the fact that agricultural and urban forests exist on a continuum defined by their relationship (and interrelationship) with a given landscape. These two forest types generally serve different purposes, however. Whereas agricultural forests are...

  20. Urbane Projekter

    DEFF Research Database (Denmark)

    Andersen, Anne Juel

    2013-01-01

    of Chapter 1 ’problem and research questions’, Chapter 2 ’place, discourse and planning as a theoretical framework’ and Chapter 3 ’research design’. Part 2 ’urban practice locally, nationally and globally’ consisting of Chapter 4 ’background and context, urban trans- formations in Aalborg from 1950 to 2013...... of Chapter 9 with the same name. The analysis results and thus the conclusions are at 3 levels of knowledge: Historically specific development in terms of urban planning practices respectively in Aalborg and natio- nally/internationally The tools here have been a focus on different rationales or urban...... projects as a strategic tool in urban policy, development of place perceptions, the use of narratives in the planning processes, the functions of representations as discursive devised imagined realities, power structures and planning approaches - knowledge that can be used in the future practice of other...

  1. Urban performances

    DEFF Research Database (Denmark)

    Samson, Kristine

    2012-01-01

    Through three different urban performances, the paper investigates how, when and under which circumstances urban space is transformed and distorted from its every day use and power relations. Distortion is an annual street festival in Copenhagen with the objective to distort the functional city...... creates an intensive space for the empowerment and liberation of the body. Occupy Wall street and its action in the autumn 2001 is the ultimate example of how urban political performances intensifies and transform every day spaces. Through examples of how OWS tactically appropriates and transforms urban...... space, I seek to show how representational space, for instance the public square, is transformed and distorted by heterogeneous and unforeseen modes of operating. Despite differing in their goal and outset, I wish to unfold an alternative to urban transformation practices in planning and architecture...

  2. A study of fish and shellfish consumers near Sellafield: assessment of the critical groups including consideration of children

    International Nuclear Information System (INIS)

    Leonard, D.R.P.; Hunt, G.J.

    1985-01-01

    A survey of people's consumption rates in 1981 and 1982, of fish and shellfish caught near the British Nuclear Fuels plc (BNFL) Sellafield site is described. Particular emphasis has been given to mollusc eaters and consumption rates of children because of the potentially higher radiation doses they may receive. Appropriate critical groups have been selected for dose assessment purposes using principles recommended by the International Commission on Radiological Protection (ICRP). Methods for consideration of children in critical groups are suggested and a comparison of these methods using the present data shows similar results. Combination of seafood consumption pathways is also considered, and it is shown that a simple additive approach is not excessively conservative. (author)

  3. Quantitative determination of fatty acids in marine fish and shellfish from warm water of Straits of Malacca for nutraceutical purposes.

    Science.gov (United States)

    Abd Aziz, Nurnadia; Azlan, Azrina; Ismail, Amin; Mohd Alinafiah, Suryati; Razman, Muhammad Rizal

    2013-01-01

    This study was conducted to quantitatively determine the fatty acid contents of 20 species of marine fish and four species of shellfish from Straits of Malacca. Most samples contained fairly high amounts of polyunsaturated fatty acids (PUFAs), especially alpha-linolenic acid (ALA, C18:3 n3), eicosapentaenoic acid (EPA, C20:5 n3), and docosahexaenoic acid (DHA, C22:6 n3). Longtail shad, yellowstripe scad, and moonfish contained significantly higher (P < 0.05) amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA), respectively. Meanwhile, fringescale sardinella, malabar red snapper, black pomfret, Japanese threadfin bream, giant seaperch, and sixbar grouper showed considerably high content (537.2-944.1 mg/100 g wet sample) of desirable omega-3 fatty acids. The polyunsaturated-fatty-acids/saturated-fatty-acids (P/S) ratios for most samples were higher than that of Menhaden oil (P/S = 0.58), a recommended PUFA supplement which may help to lower blood pressure. Yellowstripe scad (highest DHA, ω - 3/ω - 6 = 6.4, P/S = 1.7), moonfish (highest ALA, ω - 3/ω - 6 = 1.9, P/S = 1.0), and longtail shad (highest EPA, ω - 3/ω - 6 = 0.8, P/S = 0.4) were the samples with an outstandingly desirable overall composition of fatty acids. Overall, the marine fish and shellfish from the area contained good composition of fatty acids which offer health benefits and may be used for nutraceutical purposes in the future.

  4. Quantitative Determination of Fatty Acids in Marine Fish and Shellfish from Warm Water of Straits of Malacca for Nutraceutical Purposes

    Directory of Open Access Journals (Sweden)

    Nurnadia Abd Aziz

    2013-01-01

    Full Text Available This study was conducted to quantitatively determine the fatty acid contents of 20 species of marine fish and four species of shellfish from Straits of Malacca. Most samples contained fairly high amounts of polyunsaturated fatty acids (PUFAs, especially alpha-linolenic acid (ALA, C18:3 n3, eicosapentaenoic acid (EPA, C20:5 n3, and docosahexaenoic acid (DHA, C22:6 n3. Longtail shad, yellowstripe scad, and moonfish contained significantly higher (P<0.05 amounts of eicosapentaenoic acid (EPA, docosahexaenoic acid (DHA, and alpha-linolenic acid (ALA, respectively. Meanwhile, fringescale sardinella, malabar red snapper, black pomfret, Japanese threadfin bream, giant seaperch, and sixbar grouper showed considerably high content (537.2–944.1 mg/100g wet sample of desirable omega-3 fatty acids. The polyunsaturated-fatty-acids/saturated-fatty-acids (P/S ratios for most samples were higher than that of Menhaden oil (P/S=0.58, a recommended PUFA supplement which may help to lower blood pressure. Yellowstripe scad (highest DHA, ω-3/ω-6=6.4, P/S=1.7, moonfish (highest ALA, ω-3/ω-6=1.9, P/S=1.0, and longtail shad (highest EPA, ω-3/ω-6=0.8, P/S=0.4 were the samples with an outstandingly desirable overall composition of fatty acids. Overall, the marine fish and shellfish from the area contained good composition of fatty acids which offer health benefits and may be used for nutraceutical purposes in the future.

  5. Phylogenetic and functional diversity of the cultivable bacterial community associated with the paralytic shellfish poisoning dinoflagellate Gymnodinium catenatum.

    Science.gov (United States)

    Green, David H; Llewellyn, Lyndon E; Negri, Andrew P; Blackburn, Susan I; Bolch, Christopher J S

    2004-03-01

    Gymnodinium catenatum is one of several dinoflagellates that produce a suite of neurotoxins called the paralytic shellfish toxins (PST), responsible for outbreaks of paralytic shellfish poisoning in temperate and tropical waters. Previous research suggested that the bacteria associated with the surface of the sexual resting stages (cyst) were important to the production of PST by G. catenatum. This study sought to characterise the cultivable bacterial diversity of seven different strains of G. catenatum that produce both high and abnormally low amounts of PST, with the long-term aim of understanding the role the bacterial flora has in bloom development and toxicity of this alga. Sixty-one bacterial isolates were cultured and phylogenetically identified as belonging to the Proteobacteria (70%), Bacteroidetes (26%) or Actinobacteria (3%). The Alphaproteobacteria were the most numerous both in terms of the number of isolates cultured (49%) and were also the most abundant type of bacteria in each G. catenatum culture. Two phenotypic (functional) traits inferred from the phylogenetic data were shown to be a common feature of the bacteria present in each G. catenatum culture: firstly, Alphaproteobacteria capable of aerobic anoxygenic photosynthesis, and secondly, Gammaproteobacteria capable of hydrocarbon utilisation and oligotrophic growth. In relation to reports of autonomous production of PST by dinoflagellate-associated bacteria, PST production by bacterial isolates was investigated, but none were shown to produce any PST-like toxins. Overall, this study has identified a number of emergent trends in the bacterial community of G. catenatum which are mirrored in the bacterial flora of other dinoflagellates, and that are likely to be of especial relevance to the population dynamics of natural and harmful algal blooms.

  6. Determination of arsenic and cadmium in shellfish samples by graphite furnace atomic absorption spectrometry using matrix modifier

    International Nuclear Information System (INIS)

    Villalobos Aranda, Juan; Cortez Diaz, Mirella

    2003-01-01

    Serious problems of environmental contamination due to the activity of the man exist at the present time. Where the greater impact is the produced one by heavy metals that go to the sea. Where the shellfish can collect some of them, the highly toxic ones, since these are bioaccumulation of these metals. Therefore one becomes necessary to count with the reliable analytical procedures to determine these elements. The purpose of this work is to present the determination of arsenic and cadmium in shellfish, by spectroscopy of atomic absorption with graphite furnace. For each determined element, solutions of nickel and phosphate like matrix modifiers were used respectively The validation was made using a Reference Certified Material, Oyster ' Tissue 156 (National Institute of Standards and Technology). The sample previously was digested in triplicate by two consecutive days, with nitric acid in a pressure digestion system DAB 11. For each element it was evaluated: limit of detection and quantification, sensitivity, repeatability, linear, slope rank and uncertainty. In addition, the obtained results were compared with the certified values of the certified material of reference using like statistical tools the tests of Student and Fisher. In both tests the calculated values were smaller to the shown ones in table, for degrees of freedom with 95% of confidence. Thus it was verified that it does not exist significant differences between the precision and the average values of the results obtained with respect to the values of the certified material. In addition, the obtained parameters are appropriate for the determination of these trace elements in this type of environmental sample (author)

  7. Alteration of host-pathogen interactions in the wake of climate change - Increasing risk for shellfish associated infections?

    Science.gov (United States)

    Hernroth, Bodil E; Baden, Susanne P

    2018-02-01

    The potential for climate-related spread of infectious diseases through marine systems has been highlighted in several reports. With this review we want to draw attention to less recognized mechanisms behind vector-borne transmission pathways to humans. We have focused on how the immune systems of edible marine shellfish, the blue mussels and Norway lobsters, are affected by climate related environmental stressors. Future ocean acidification (OA) and warming due to climate change constitute a gradually increasing persistent stress with negative trade-off for many organisms. In addition, the stress of recurrent hypoxia, inducing high levels of bioavailable manganese (Mn) is likely to increase in line with climate change. We summarized that OA, hypoxia and elevated levels of Mn did have an overall negative effect on immunity, in some cases also with synergistic effects. On the other hand, moderate increase in temperature seems to have a stimulating effect on antimicrobial activity and may in a future warming scenario counteract the negative effects. However, rising sea surface temperature and climate events causing high land run-off promote the abundance of naturally occurring pathogenic Vibrio and will in addition, bring enteric pathogens which are circulating in society into coastal waters. Moreover, the observed impairments of the immune defense enhance the persistence and occurrence of pathogens in shellfish. This may increase the risk for direct transmission of pathogens to consumers. It is thus essential that in the wake of climate change, sanitary control of coastal waters and seafood must recognize and adapt to the expected alteration of host-pathogen interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Urban Perspectives

    DEFF Research Database (Denmark)

    Reeh, Henrik

    2016-01-01

    . Kracauer’s essay may even provide a conceptual basis for critical studies of modern urbanity. Yet one has to establish a clear distinction between culture industry (e.g. the Tiller Girls) and urban culture. In everyday life as well as in Kracauer’s writings about it, the sphere of city culture may...... transcend capitalist Ratio and enter the domain of utopian fantasy. Far from automatically reproducing the logic of capital, the ornaments of the city provide occasions for cultural and social change. This is what Kracauer is hinting at when he makes improvisation the prime criterion of urban quality....

  9. Urban Modality

    Directory of Open Access Journals (Sweden)

    Jorge Gil

    2016-02-01

    Full Text Available This thesis proposes a framework for evaluating the mobility potential and performance of urban areas in the city region, as an instrument to support urban development that contributes positively to regional sustainable mobility objectives. The research takes a quantitative approach, modelling and measuring the characteristics of a city-region and of its individual urban areas, in terms of travel patterns and socioeconomic characteristics of the resident population, and in terms of built environment characteristics. It then explores how the built environment defines the affordances of urban areas for travelling by particular modes of transport, i.e. its walk-ability, cycleability, drive-ability and transit-ability, by developing a typology of what I call their ‘urban modality’. And finally the work combines this typology with the socio-economic characteristics of urban areas to determine their sustainable mobility potential and performance. It focuses on the case of the Randstad region of the Netherlands and its VINEX neighbourhoods, which are an emblematic example of new urban areas created under a policy programme with sustainable mobility objectives. A key stance in this work is the understanding that the location of an urban area in the region can be indicative of its population’s travel patterns, because the built environment (infrastructural and socio-economic characteristics are interrelated and present strong regional spatial patterns. What types of urban areas support sustainable travel patterns, and what are their spatial characteristics? How do new neighbourhoods compare to the best performing urban areas, and to other areas of the same ‘modality’ type? These are some of the questions addressed in this study. There are two main contributions of this research: the methods for building and analysing integrated multimodal network models, and the framework for contextual performance evaluation using urban area typologies. The

  10. Informational Urbanism

    Directory of Open Access Journals (Sweden)

    Wolfgang G. Stock

    2015-10-01

    Full Text Available Contemporary and future cities are often labeled as "smart cities," "ubiquitous cities," "knowledge cities" and "creative cities." Informational urbanism includes all aspects of information and knowledge with regard to urban regions. "Informational city" is an umbrella term uniting the divergent trends of information-related city research. Informational urbanism is an interdisciplinary endeavor incorporating on the one side computer science and information science and on the other side urbanism, architecture, (city economics, and (city sociology. In our research project on informational cities, we visited more than 40 metropolises and smaller towns all over the world. In this paper, we sketch the theoretical background on a journey from Max Weber to the Internet of Things, introduce our research methods, and describe main results on characteristics of informational cities as prototypical cities of the emerging knowledge society.

  11. Urban hydrology

    Science.gov (United States)

    The Third International Conference on Urban Storm Drainage will be held in Goteborg, Sweden, June 4-8, 1984. Contact A. Sjoborg, Chalmers Univ. of Technology, Goteborg, Sweden, for more information. The Fourth Conference will be in late August 1987 in Lausanne, Switzerland, and the Fifth Conference is planned for Tokyo in 1990. The proceedings of the First International Conference, held in Southampton, England, in April 1978, are available from Wiley-Interscience under the title “Urban Storm Drainage.”The proceedings of the Second International Conference, held in Urbana, Illinois, in June 1981, are available from Water Resources Publications, Littleton, Colo., under the title, “Urban Stormwater Hydraulics and Hydrology” and “Urban Stormwater Quality, Management, and Planning.”

  12. Urban interventions

    DEFF Research Database (Denmark)

    Pinder, David

    2008-01-01

    Challenging perspectives on the urban question have arisen in recent years from beyond academic realms through the work of artists and cultural practitioners. Often in dialogue with urban theory and political activism, and employing a range of tactical practices, they have engaged critically......, relationships and situations. Such interventionist practices may rarely be seen as part of the traditional purview of urban studies. Yet in asserting their significance here, this essay argues that growing dialogues across and between urban and spatial theory, and artistic and cultural practice, have...... considerable potential for inspiring and developing critical approaches to cities. The essay highlights a number of specific challenges thrown up by such interconnections that are of political and pedagogical significance and in need of further debate....

  13. Urban Mining

    DEFF Research Database (Denmark)

    2015-01-01

    The catalogue is one of the results of a small taught course at teh Aarhus School of Architecture. The course was offered to bachelor students and was specific focused on harvesting materials in an urban context and on building with waste.......The catalogue is one of the results of a small taught course at teh Aarhus School of Architecture. The course was offered to bachelor students and was specific focused on harvesting materials in an urban context and on building with waste....

  14. Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data from current meter and other instruments in the Gulf of Mexico from 1993-01-26 to 1994-06-13 (NODC Accession 9500088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data were collected using current meter and other...

  15. Marine Fish and Shellfish Survey data from otter trawls in the Chukchi Sea from the OCEAN HOPE 3 and OSHORO MARU from 16 August 1990 to 31 July 1992 (NODC Accession 9400061)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine Fish and Shellfish Survey data were collected from otter trawls in the Chukchi Sea from the OCEAN HOPE. Data were collected by the University of Alaska from...

  16. Urban atmospheres.

    Science.gov (United States)

    Gandy, Matthew

    2017-07-01

    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  17. Urbane spil

    DEFF Research Database (Denmark)

    Løssing, Tobias

    2006-01-01

    PhD afhandling: 1: Urbane spil 2: [brand TILST] - den nye forstad. 3: 6400:Kollision - udstilling på Sønderborg Slot 2001 4: 4: [0.2:Kollision] - Charlottenborgs Forårsudstilling 2002 5: Havnen på spil - debatten om de bynære havnearealer i Århus 2002-2004 Manual - uddybet guide til PhD-projektet......PhD afhandling: 1: Urbane spil 2: [brand TILST] - den nye forstad. 3: 6400:Kollision - udstilling på Sønderborg Slot 2001 4: 4: [0.2:Kollision] - Charlottenborgs Forårsudstilling 2002 5: Havnen på spil - debatten om de bynære havnearealer i Århus 2002-2004 Manual - uddybet guide til Ph......D-projektet Urbane spil Se også www.urbanespil.dk...

  18. Optimization of hydrophilic interaction liquid chromatography/mass spectrometry and development of solid-phase extraction for the determination of paralytic shellfish poisoning toxins.

    Science.gov (United States)

    Turrell, Elizabeth; Stobo, Lesley; Lacaze, Jean-Pierre; Piletsky, Sergey; Piletska, Elena

    2008-01-01

    The combination of hydrophilic interaction liquid chromatography (HILIC) and liquid chromatography/mass spectrometry (LC/MS) for the determination of paralytic shellfish poisoning (PSP) toxins has been proposed for use in routine monitoring of shellfish. In this study, methods for the detection of multiple PSP toxins [saxitoxin (STX), neosaxitoxin (NEO), decarbamoyl saxitoxin (dcSTX), decarbamoyl neosaxitoxin (dcNEO), gonyautoxins 1-5 (GTX1, GTX2, GTX3, GTX4, GTX5), decarbamoyl gonyautoxins (dcGTX2 and dcGTX3), and the N-sulfocarbamoyl C toxins (C1 and C2)] were optimized using single (MS) and triple quadrupole (MS/MS) instruments. Chromatographic separation of the toxins was achieved by using a TSK-gel Amide-80 analytical column, although superior chromatography was observed through application of a ZIC-HILIC column. Preparative procedures used to clean up shellfish extracts and concentrate PSP toxins prior to analysis were investigated. The capacity of computationally designed polymeric (CDP) materials and HILIC solid-phase extraction (SPE) cartridges to retain highly polar PSP toxins was explored. Three CDP materials and 2 HILIC cartridges were assessed for the extraction of PSP toxins from aqueous solution. Screening of the CDPs showed that all tested polymers adsorbed PSP toxins. A variety of elution procedures were examined, with dilute 0.01% acetic acid providing optimum recovery from a CDP based on 2-(trifluoromethyl)acrylic acid as the monomer. ZIC-HILIC SPE cartridges were superior to the PolyLC equivalent, with recoveries ranging from 70 to 112% (ZIC-HILIC) and 0 to 90% (PolyLC) depending on the PSP toxin. It is proposed that optimized SPE and HILIC-MS methods can be applied for the quantitative determination of PSP toxins in shellfish.

  19. Laurus nobilis, Zingiber officinale and Anethum graveolens essential oils: Composition, antioxidant and antibacterial activities against bacteria isolated from fish and shellfish

    OpenAIRE

    Snuossi, M.; Trabelsi, N.; Taleb, S. B.; Dehmeni, A.; Flamini, G.; De Feo, V.

    2016-01-01

    Several bacterial strains were isolated from wild and reared fish and shellfish. The identification of these strains showed the dominance of the Aeromonas hydrophila species in all seafood samples, followed by Staphylococcus spp., Vibrio alginolyticus, Enterobacter cloacae, Klebsiella ornithinolytica, Klebsiella oxytoca and Serratia odorifera. The isolates were studied for their ability to produce exoenzymes and biofilms. The chemical composition of the essential oils from Laurus nobilis leav...

  20. Seasonal variability of Dinophysis spp. and Protoceratium reticulatum associated to lipophilic shellfish toxins in a strongly stratified Chilean fjord

    Science.gov (United States)

    Alves-de-Souza, Catharina; Varela, Daniel; Contreras, Cristóbal; de La Iglesia, Pablo; Fernández, Pamela; Hipp, Byron; Hernández, Cristina; Riobó, Pilar; Reguera, Beatriz; Franco, José M.; Diogène, Jorge; García, Carlos; Lagos, Néstor

    2014-03-01

    The fine scale vertical distribution of Dinophysis spp. and Protoceratium reticulatum (potential producers of lipophilic shellfish toxins, LSTs) and its relation with LSTs in shellfish was studied in Reloncaví fjord, a strongly stratified system in Southern Chile. Samples were taken over two years from late spring to early autumn (2007-2008 period) and from early spring to late summer (2008-2009 period). Dinophysis spp., in particular Dinophysis acuminata, were always detected, often forming thin layers in the region of the salinity driven pycnocline, with cell maxima for D. acuminata of 28.5×103 cells L-1 in March 2008 and 17.1×103 cells L-1 in November 2008. During the 2008-2009 sampling period, blooms of D. acuminata co-occurred with high densities of cryptophyceans and the ciliate Mesodinium spp. The highest levels of pectenotoxin-2 (PTX-2; 2.2 ng L-1) were found in the plankton in February 2009, associated with moderate densities of D. acuminata, Dinophysis tripos and Dinophysis subcircularis (0.1-0.6×103 cells L-1). However, only trace levels of PTX-2 were observed in bivalves at that time. Dinophysistoxin (DTX-1 and DTX-3) levels in bivalves and densities of Dinophysis spp. were not well correlated. Low DTX levels in bivalves observed during a major bloom of D. acuminata in March 2008 suggested that there is a large seasonal intraspecific variability in toxin content of Dinophysis spp. driven by changes in population structure associated with distinct LST toxin profiles in Reloncaví fjord during the study period. A heterogeneous vertical distribution was also observed for P. reticulatum, whose presence was restricted to summer months. A bloom of this species of 2.2×103 cells L-1 at 14 m depth in February 2009 was positively correlated with high concentrations of yessotoxins in bivalves (51-496 ng g-1) and plankton samples (3.2 ng L-1). Our results suggest that a review of monitoring strategies for Dinophysis spp. in strongly stratified fjord systems

  1. Determination of arsenic and cadmium in shellfish samples by graphite furnace atomic absorption spectrometry using matrix modifier

    International Nuclear Information System (INIS)

    Cortez Diaz, Mirella del Carmen

    2002-01-01

    Heavy metals are a big source of environmental contamination and are also highly toxic to humans. Since shellfish are bio-accumulators of these metals, proper techniques for quantifying them should be available. This work aims to develop an analytical method for the quantitative determination of heavy metals in biological materials (shellfish), specifically arsenic and cadmium at the trace level, using graphite furnace atomic absorption spectrometry, for which nickel and phosphate solutions were used to modify the modifiers. Prior to the analysis, the sample was diluted with nitric acid in a DAB II pressure digestion system order to destroy the organic matter. The instrument conditions were initially set (wavelength, slit, integration peaks, graphite tube, etc.), then the work range was defined for each element and the most appropriate operational parameters were studied, such as: temperature, ramp times, hold times and internal gas flow, in the different stage of the electrothermal treatment (drying, calcination, atomization) for the furnace program. Once the above mentioned conditions were set and since this was a biological sample, a matrix chemical modifier had to be used, in order to make the elements that accompany the element being studied more volatile. In this way the chemical and spectral interferences decrease together with the high background absorption of the matrix. Therefore, different matrix modifiers were studied for the definition of each analyte. The method validation was done using Certified Oyster Tissue Reference Material N o 1566a from the National Institute of Standards and Technology applying different tests in order to eliminate outliers. Repeatability, uncertainty, sensitivity, lineal range, working range, detection limit and quantification limit were evaluated for each element, and the results were compared with the values for the certified material. The Fisher and Student tests were the statistical tools used. The experimental values

  2. EVALUATION OF URBANIZATION INFLUENCES ON URBAN ...

    African Journals Online (AJOL)

    Osondu

    2012-07-27

    Jul 27, 2012 ... climate over the cities that affect human comfort and his environment. Proper urban ... Key Words: Urbanization, Comfort, Pollution, Modification, Albedo, Urban Heat Island ... effects of land surface change on the climate of a.

  3. Innovations in urban agriculture

    NARCIS (Netherlands)

    Schans, van der J.W.; Renting, Henk; Veenhuizen, Van René

    2014-01-01

    This issuehighlights innovations in urban agriculture. Innovation and the various forms of innovations are of particular importance because urban agriculture is adapted to specific urban challenges and opportunities. Innovation is taking place continuously, exploring the multiple fundions of urban

  4. Urban Poverty in Asia

    OpenAIRE

    Asian Development Bank (ADB); Asian Development Bank (ADB); Asian Development Bank (ADB); Asian Development Bank (ADB)

    2014-01-01

    This report provides an overview of important urban poverty questions. What defines urban poverty and how is urban poverty being measured? What other factors beyond consumption poverty need to be tackled? Who are the urban poor? What relations exist between urban poverty and city size? What linkages exist between urbanization, income, and urban poverty? What policy responses to urban poverty are implemented in selected Asian countries? The report served as a background study for the Internati...

  5. Contested Urbanism

    DEFF Research Database (Denmark)

    Pløger, John

    2010-01-01

    Iconic architecture plays a crucial role in cities' interurban competition. This is also the case with Copenhagen which has used iconic architecture as part of its boosterism to gain investment, to increase tourism and to attract the creative class. This battle over the symbolic representation of...... intertwined through symbolic, visual and virtual representations of the wrongs of current urban planning...

  6. Virtual Urbanism.

    Science.gov (United States)

    Sirc, Geoffrey

    2001-01-01

    Considers how visual literacy implies a poetics of technology, one rooted in basic human passion. Notes that most academic forms sanctioned for students to inhabit are as monumentally dull as the urban forms in which they pass an extra-academic portion of their lives. Concludes that technology is most useful when it allows the poetic spirit to…

  7. Future oceanic warming and acidification alter immune response and disease status in a commercial shellfish species, Mytilus edulis L.

    Directory of Open Access Journals (Sweden)

    Clara L Mackenzie

    Full Text Available Increases in atmospheric carbon dioxide are leading to physical changes in marine environments including parallel decreases in ocean pH and increases in seawater temperature. This study examined the impacts of a six month exposure to combined decreased pH and increased temperature on the immune response and disease status in the blue mussel, Mytilus edulis L. Results provide the first confirmation that exposure to future acidification and warming conditions via aquarium-based simulation may have parallel implications for bivalve health. Collectively, the data suggests that temperature more than pH may be the key driver affecting immune response in M. edulis. Data also suggests that both increases in temperature and/or lowered pH conditions may lead to changes in parasite abundance and diversity, pathological conditions, and bacterial incidence in M. edulis. These results have implications for future management of shellfish under a predicted climate change scenario and future sustainability of shellfisheries. Examination of the combined effects of two stressors over an extended exposure period provides key preliminary data and thus, this work represents a unique and vital contribution to current research efforts towards a collective understanding of expected near-future impacts of climate change on marine environments.

  8. Prevalence of human pathogenic enteric viruses in bivalve molluscan shellfish and cultured shrimp in south west coast of India.

    Science.gov (United States)

    Umesha, Kanasinakatte R; Bhavani, Naniah C; Venugopal, Moleyur N; Karunasagar, Indrani; Krohne, Georg; Karunasagar, Iddya

    2008-03-20

    The prevalence of human enteric viruses in bivalve molluscan shellfish and shrimp collected off the south west coast of India was studied to assess the extent of fecal pollution of coastal environment. Out of 194 samples analyzed, 37% of oyster, 46% of clam and 15% of shrimp samples were positive for enteroviruses (EV). Adenoviruses (ADV) were detected in 17% of oyster and 27% of clam samples. However, other enteric viruses such as noroviruses (NoV) and hepatitis A virus (HAV) were not detected in any of the samples. High prevalence of EV and ADV was noticed between May to December. Thirty four percent of oyster and 49% of clam samples showed fecal coliform values higher than the limit. MS-2 phage was detected in 57% of oyster and 73% of clam samples. The presence of MS-2 phage and human enteric viruses showed association while fecal coliforms and enteric viruses showed no association. However, 17 samples, which were positive for enteric viruses (EV and ADV), were negative for MS-2 phage.

  9. Apoptosis of hemocytes from lions-paw scallop Nodipecten subnodosus induced with paralyzing shellfish poison from Gymnodinium catenatum.

    Science.gov (United States)

    Estrada, Norma; Ascencio, Felipe; Shoshani, Liora; Contreras, Rubén G

    2014-12-01

    The toxic dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons (PSPs) that are consumed and accumulated by bivalves. Previously, we recorded a decrease in hemocytes 24h after injection of PSPs (gonyautoxin 2/3 epimers, GTX2/3) in the adductor muscle in the lions-paw scallop Nodipecten subnodosus. In this work, qualitative and quantitative analyses, in in vivo and in vitro experiments, revealed that the lower count of hemocytes results from cells undergoing typical apoptosis when exposed to GTX 2/3 epimers. This includes visible morphological alterations of the cytoplasmic membrane, damage to the nuclear membrane, condensation of chromatin, DNA fragmentation, and release of DNA fragments into the cytoplasm. Induction of apoptosis was accompanied by phosphatidylserine exposure to the outer cell membrane and activation of cysteine-aspartic proteases, caspase 3 and caspase 8. Addition of an inhibitor of caspase to the medium suppressed activation in hemocytes exposed to the toxins, suggesting that cell death was induced by a caspase-dependent apoptotic pathway. The results are important for future investigation of the scallop's immune system and should provide new insights into apoptotic processes in immune cells of scallops exposed to PSPs. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Uptake and release of paralytic shellfish toxins by the clam Ruditapes decussatus exposed to Gymnodinium catenatum and subsequent depuration.

    Science.gov (United States)

    Botelho, Maria João; Vale, Carlos; Grilo, Rita Velez; Ferreira, João Gomes

    2012-06-01

    A laboratory experiment was performed with the clam Ruditapes decussatus, fed with the toxic dinoflagellate Gymnodinium catenatum and the non-toxic algae Isochrysis galbana (14 days) and subsequently only with I. galbana (15 days). Individual paralytic shellfish toxins were determined by LC-FLD in G. catenatum cells, whole clam tissues, and particulate organic matter (POM) produced by clams. The toxins dcSTX and dcGTX2 + 3 in the algae were less abundant than C1 + 2 and B1, but were predominant in clams during both the exposure and depuration phases. The toxin dcNEO was only detected in clams during a short period, indicating conversion from other compounds. The toxin composition of the POM indicated the export of dcSTX as faeces or pseudo-faeces along the entire experiment (2.5-14 nmol mg(-1)), B1 was present in a short period of the exposure and C1 + 2 and dcGTX2 + 3 absent. A mass balance calculation indicated that approximately 95% of C1 + 2 and 85% of B1 supplied to the clams were converted into other toxins or lost in solution. Conversely, the net gain of 512, 61 and 31 nmol for dcSTX, dcGTX2 + 3 and dcNEO, respectively, suggests the conversion from other assimilated compounds by clams during exposure and depuration phases. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Immunoassay of paralytic shellfish toxins by moving magnetic particles in a stationary liquid-phase lab-on-a-chip.

    Science.gov (United States)

    Kim, Myoung-Ho; Choi, Suk-Jung

    2015-04-15

    In this study, we devised a stationary liquid-phase lab-on-a-chip (SLP LOC), which was operated by moving solid-phase magnetic particles in the stationary liquid phase. The SLP LOC consisted of a sample chamber to which a sample and reactants were added, a detection chamber containing enzyme substrate solution, and a narrow channel connecting the two chambers and filled with buffer. As a model system, competitive immunoassays of saxitoxin (STX), a paralytic shellfish toxin, were conducted in the SLP LOC using protein G-coupled magnetic particles (G-MPs) as the solid phase. Anti-STX antibodies, STX-horseradish peroxidase conjugate, G-MPs, and a STX sample were added to the sample chamber and reacted by shaking. While liquids were in the stationary state, G-MPs were transported from the sample chamber to the detection chamber by moving a magnet below the LOC. After incubation to allow the enzymatic reaction to occur, the absorbance of the detection chamber solution was found to be reciprocally related to the STX concentration of the sample. Thus, the SLP LOC may represent a novel, simple format for point-of-care testing applications of enzyme-linked immunosorbent assays by eliminating complicated liquid handling steps. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Remarkable difference in paralytic shellfish poisoning toxin distribution in tissues of pen shell atrina pectinata exposed to toxic red tide bloom

    International Nuclear Information System (INIS)

    Narceda, Ronald Jefferson A.; Montojo, Ulysses M.; Cayme, Mirriam F.; Borja, Valeriano M.

    2011-01-01

    Pen shell atrina pectinata is one of the commercially important bivalves in Western Pacific region. In the Philippines, it is marketed as a whole meat or processed by shellfish harvesters to separate the abductor muscle as an export commodity. During blooms of toxic dinoflagellate pyrodinium bahamense var. compressum (Pbc), A. pectinata accumulates paralytic shellfish poisoning (PSP) toxins sometimes exceeding Philippine regulatory limit of 60μgSTXeq/100g tissue and international regulatory limit of 80μgSTXeq/100g tissue for safe human consumption, based on whole tissue analysis. Toxic blooms directly affect the shellfish industry which includes A. pectinata, and this causes not only significant economical losses on shellfish gatherers but also serious public health concerns. In this study, samples of A. pectinata exposed to toxic bloom of Pbc were collected in Sorsogon Bay, Philippines. Bioaccumulation and distribution of PSP toxins were determined in different tissues namely, abductor muscle, mantle, gills, gonads, siphon, stomach and intestine using High Performance Liquid Chromatography post column derivatization method with fluorescence detection. Likewise, green mussels Perna viridis being the sentinel species for PSP monitoring in the Philippines were also collected in the same area and served as control. Interestingly, results showed that the abductor muscle accumulates minimal level of PSP toxins and is several folds lower than the Philippine and international regulatory limits in contrast with the results obtained from P. viridis. Mantle parts showed toxicity values exceeding local regulatory limit and near to go beyond the international regulatory limit. Conversely, the remaining parts showed high toxicity values surpassing both regulation limits. Standard mouse bioassay regulatory used in PSP monitoring in the Philippines was also performed and revealed that the abductor muscle had non-detectable level of toxins. Also, toxicity values from different

  13. Green urbanity

    Directory of Open Access Journals (Sweden)

    Alenka Fikfak

    2012-01-01

    Full Text Available Tourism and other culture-based types of small business, which are the leitmotif in the planning of the Europark Ruardi, are becoming the guiding motif in the spatial development of urban centres that are influenced by dynamic transformation processes. The system should build upon the exploitation of both local and regional environmental features. This would encourage the quest for special environmental features, with an emphasis on their conservation, i.e. sustainable development, and connections in a wider context.The Europark is seen as a new strategic point of the Zasavje Region (the region of the central Sava Valley, which is linked to other important points in a region relevant for tourism. Due to the "smallness" of the region and/or the proximity of such points, development can be fast and effective. The interaction of different activities in space yields endless opportunities for users, who choose their own goals and priorities in the use of space. Four theme areas of the Europark area planning are envisaged. The organisation of activities is based on the composition of the mosaic field patterns, where green fields intertwine with areas of different, existing and new, urban functions. The fields of urban and recreation programmes are connected with a network of green areas and walking trails, along which theme park settings are arranged.

  14. Urbanism & urban qualities New data and methodologies

    DEFF Research Database (Denmark)

    2009-01-01

    The interest in urban spaces and their qualities has become stronger in recent years. A substantial volume of projects aims to create attractive urban spaces reasons of Sustainability, Quality of Life and urban vitality. But who actually uses the urban spaces, which urban spaces are used? How do...... they use them? What characterizes the good urban space? And how and by who is it evaluated? How is a better co-operation between urban space researchers, decision makers and users established? Is it the right urban spaces which receive investments? How can research optimize the basis for decisions......?   Proceedings from the conference "Urbanism & urban qualities - new data & methodologies" held 24th of June 2009 at The Royal Danish Academy of Fine Arts in Copenhagen....

  15. Biotransformation modulation and genotoxicity in white seabream upon exposure to paralytic shellfish toxins produced by Gymnodinium catenatum

    International Nuclear Information System (INIS)

    Reis Costa, Pedro; Pereira, Patrícia; Guilherme, Sofia; Barata, Marisa; Nicolau, Lídia; Santos, Maria Ana; Pacheco, Mário; Pousão-Ferreira, Pedro

    2012-01-01

    Fish are recurrently exposed to paralytic shellfish toxins (PSTs) produced by Gymnodinium catenatum. Nevertheless, the knowledge regarding metabolism of PSTs and their toxic effects in fish is scarce. Consequently, the current study aims to investigate the role of phase I and II detoxification enzymes on PST metabolism in the liver of white seabream (Diplodus sargus), assessing ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities. Moreover, the genotoxic potential of PSTs was examined through the erythrocytic nuclear abnormality (ENA) assay. Fish were intracoelomically (IC) injected with a nominal dose (expressed as saxitoxin equivalents) of 1.60 μg STXeq kg −1 semipurified from a G. catenatum cell culture with previously determined toxin profile. Fish were sacrificed 2 and 6 days after IC injection. PST levels determined in fish liver were15.2 and 12.2 μg STXeq kg −1 , respectively, at 2 and 6 days after the injection. Though several PSTs were administered, only dcSTX was detected in the liver after 2 and 6 days. This was regarded as an evidence that most of the N-sulfocarbamoyl and decarbamoyl toxins were rapidly biotransformed in D. sargus liver and/or eliminated. This was corroborated by a hepatic GST activity induction at 2 days after injection. Hepatic EROD activity was unresponsive to PSTs, suggesting that these toxins enter phase II of biotransformation directly. The genotoxic potential of PSTs was also demonstrated; these toxins were able to induce cytogenetic damage, such as chromosome (or chromatid) breaks or loss and segregational anomalies, measured by the ENA assay. Overall, this study pointed out the ecological risk associated with the contamination of fish with PSTs generated by G. catenatum blooms, providing the necessary first data for a proper interpretation of biomonitoring programs aiming to assess the impact of phytoplankton blooms in fish.

  16. Biotransformation modulation and genotoxicity in white seabream upon exposure to paralytic shellfish toxins produced by Gymnodinium catenatum

    Energy Technology Data Exchange (ETDEWEB)

    Reis Costa, Pedro, E-mail: prcosta@ipimar.pt [IPIMAR - National Institute for Biological Resources (INRB/IPIMAR), Av. Brasilia, 1449-006 Lisboa (Portugal); Pereira, Patricia [IPIMAR - National Institute for Biological Resources (INRB/IPIMAR), Av. Brasilia, 1449-006 Lisboa (Portugal); Department of Biology and CESAM, Aveiro University, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Guilherme, Sofia [Department of Biology and CESAM, Aveiro University, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Barata, Marisa; Nicolau, Lidia [IPIMAR - National Institute for Biological Resources (INRB/IPIMAR), Av. 5 Outubro, 8700-305 Olhao (Portugal); Santos, Maria Ana; Pacheco, Mario [Department of Biology and CESAM, Aveiro University, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Pousao-Ferreira, Pedro [IPIMAR - National Institute for Biological Resources (INRB/IPIMAR), Av. 5 Outubro, 8700-305 Olhao (Portugal)

    2012-01-15

    Fish are recurrently exposed to paralytic shellfish toxins (PSTs) produced by Gymnodinium catenatum. Nevertheless, the knowledge regarding metabolism of PSTs and their toxic effects in fish is scarce. Consequently, the current study aims to investigate the role of phase I and II detoxification enzymes on PST metabolism in the liver of white seabream (Diplodus sargus), assessing ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities. Moreover, the genotoxic potential of PSTs was examined through the erythrocytic nuclear abnormality (ENA) assay. Fish were intracoelomically (IC) injected with a nominal dose (expressed as saxitoxin equivalents) of 1.60 {mu}g STXeq kg{sup -1} semipurified from a G. catenatum cell culture with previously determined toxin profile. Fish were sacrificed 2 and 6 days after IC injection. PST levels determined in fish liver were15.2 and 12.2 {mu}g STXeq kg{sup -1}, respectively, at 2 and 6 days after the injection. Though several PSTs were administered, only dcSTX was detected in the liver after 2 and 6 days. This was regarded as an evidence that most of the N-sulfocarbamoyl and decarbamoyl toxins were rapidly biotransformed in D. sargus liver and/or eliminated. This was corroborated by a hepatic GST activity induction at 2 days after injection. Hepatic EROD activity was unresponsive to PSTs, suggesting that these toxins enter phase II of biotransformation directly. The genotoxic potential of PSTs was also demonstrated; these toxins were able to induce cytogenetic damage, such as chromosome (or chromatid) breaks or loss and segregational anomalies, measured by the ENA assay. Overall, this study pointed out the ecological risk associated with the contamination of fish with PSTs generated by G. catenatum blooms, providing the necessary first data for a proper interpretation of biomonitoring programs aiming to assess the impact of phytoplankton blooms in fish.

  17. Health-Related Quality of Life among Artisanal Fisherwomen/Shellfish Gatherers: Lower than the General Population

    Directory of Open Access Journals (Sweden)

    Juliana dos Santos Müller

    2016-05-01

    Full Text Available Quality of life is an indicator of how well one perceives that he/she is functioning physically and mentally. The aim of this paper is to determine the health-related quality of life (HRQOL of artisanal fisherwomen/shellfish gatherers from the Saubara municipality in Bahia, Brazil in comparison to the general population. A structured questionnaire was administered to a sample of 209 artisanal fisherwomen selected at random. The HRQOL questionnaire, known as the 36-Item Short-Form Health Survey version 1 (SF-36v01, was also used, having been translated and verified cross-culturally for the Brazilian population. Sociodemographic, lifestyle and comorbidity information was also collected. Chronic diseases and indicators of musculoskeletal disorders (MSDs were self-reported. The study population consisted primarily of individuals between 30 and 45 years of age (78%, of self-classified races black or brown (96.2%, with no more than an elementary school education (77% and married (64.6%. In all the SF-36v01 dimensions, the values in the sample were lower than in the general population of Brazil, which was used as the reference population. In the “Physical Health” domain (Physical Functioning; Physical Role Limitations; Bodily Pain; General Health Perception a tendency toward a lower health-related quality of life was observed among those who were older, had a lower education level, and had a prevalence of MSDs, hypertension or arthritis. The interference of health conditions linked to the fisherwomen’s work activities may contribute to lower HRQOL in all analyzed aspects, in comparison to the general population. In light of these findings, public health policies must consider these informal workers who contribute greatly to Brazil’s economy and food system.

  18. Paralytic shellfish poisoning due to ingestion of Gymnodinium catenatum contaminated cockles--application of the AOAC HPLC official method.

    Science.gov (United States)

    Rodrigues, Susana Margarida; de Carvalho, Mamede; Mestre, Tiago; Ferreira, Joaquim J; Coelho, Miguel; Peralta, Rita; Vale, Paulo

    2012-04-01

    The potent paralytic shellfish toxins (PSTs) produced by Gymnodinium catenatum have appeared irregularly since the onset in 1986 of a monitoring program aimed at preventing contaminated bivalves from the Portuguese coast to reaching the consumer. In years where high contamination levels were attained, sporadic episodes of human poisonings were also recorded, as in 1994. The reappearance of high contamination led to the appearance of new cases during 2007. This study reports details of toxin ingestion, symptomatology and toxin presence in the fluids of one of these victims, an adult male who ingested several kilograms of cockles. In cockle samples collected the week before and during the week when the intoxication took place, the major PSTs detected by the HPLC method based on AOAC Official Method 2005.06 belonged to the sulfamate (81-68 molar percent) and decarbamoyl groups (19-32 molar percent), comprising GTX5, GTX6, C1,2, C3,4, dcNeo, and dcSTX. In the patient urine sample sulfamate and decarbamoyl derivatives were also found, comprising by GTX5 (28%), GTX6 (25%), dcSTX (24%) and dcNeo (22%), but no C toxins and no dcGTX2,3 were detected. Compared to the cockle samples, there was an increase in the proportion of dcSTX, dcNeo and GTX5 (molar percentage) in the urine sample, but not of GTX6. Overall, compounds which had the presence of an O-sulfate at C11 were absent in urine while being relatively abundant in the bivalve (36.5-47.0 molar percent). In blood plasma PSTs were not detected. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Biotransformation modulation and genotoxicity in white seabream upon exposure to paralytic shellfish toxins produced by Gymnodinium catenatum.

    Science.gov (United States)

    Costa, Pedro Reis; Pereira, Patrícia; Guilherme, Sofia; Barata, Marisa; Nicolau, Lídia; Santos, Maria Ana; Pacheco, Mário; Pousão-Ferreira, Pedro

    2012-01-15

    Fish are recurrently exposed to paralytic shellfish toxins (PSTs) produced by Gymnodinium catenatum. Nevertheless, the knowledge regarding metabolism of PSTs and their toxic effects in fish is scarce. Consequently, the current study aims to investigate the role of phase I and II detoxification enzymes on PST metabolism in the liver of white seabream (Diplodus sargus), assessing ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities. Moreover, the genotoxic potential of PSTs was examined through the erythrocytic nuclear abnormality (ENA) assay. Fish were intracoelomically (IC) injected with a nominal dose (expressed as saxitoxin equivalents) of 1.60 μg STXeq kg⁻¹ semipurified from a G. catenatum cell culture with previously determined toxin profile. Fish were sacrificed 2 and 6 days after IC injection. PST levels determined in fish liver were 15.2 and 12.2 μg STXeq kg⁻¹, respectively, at 2 and 6 days after the injection. Though several PSTs were administered, only dcSTX was detected in the liver after 2 and 6 days. This was regarded as an evidence that most of the N-sulfocarbamoyl and decarbamoyl toxins were rapidly biotransformed in D. sargus liver and/or eliminated. This was corroborated by a hepatic GST activity induction at 2 days after injection. Hepatic EROD activity was unresponsive to PSTs, suggesting that these toxins enter phase II of biotransformation directly. The genotoxic potential of PSTs was also demonstrated; these toxins were able to induce cytogenetic damage, such as chromosome (or chromatid) breaks or loss and segregational anomalies, measured by the ENA assay. Overall, this study pointed out the ecological risk associated with the contamination of fish with PSTs generated by G. catenatum blooms, providing the necessary first data for a proper interpretation of biomonitoring programs aiming to assess the impact of phytoplankton blooms in fish. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Depuration kinetics of paralytic shellfish toxins in Mytilus galloprovincialis exposed to Gymnodinium catenatum: laboratory and field experiments.

    Science.gov (United States)

    Botelho, Maria João; Vale, Carlos; Mota, Ana M; S Simões Gonçalves, Maria de Lurdes

    2010-12-01

    The kinetics of paralytic shellfish toxins in Mytilus galloprovincialis, previously exposed to Gymnodinium catenatum, was studied under depuration laboratory conditions and over a declining bloom of the dinoflagellate in the field. The variation of the levels observed throughout the laboratory experiment was characterized by a fast depuration of B1, C1 + 2, dcSTX and dcGTX2 + 3, possibly due to the gut evacuation of unassimilated toxins or microalgae cells, or loss during digestive mechanisms. Subsequent enhancements were observed for all compounds with emphasis to dcSTX and dcGTX2 + 3, pointing to biotransformation of the assimilated toxins. Then levels decreased gradually. A first-order depuration kinetic model fitted well to the decrease of B1, C1 + 2 and dcGTX2 + 3 concentrations, but not for dcSTX. Mussels exposed to a declining bloom of Gymnodinium catenatum exhibited a loss of toxins following the same pattern. Despite the low abundance of this dinoflagellate, a similar kinetic model was applied to the field data. The depuration rate of dcGTX2 + 3 in the field experiment (0.153 ± 0.03 day(-1)) significantly exceeded the value calculated in the laboratory (0.053 ± 0.01 day(-1)), while smaller differences were obtained for B1 (0.071 ± 0.02 and 0.048 ± 0.01 day(-1)) and similar values for C1 + 2 (0.082 ± 0.03 and 0.080 ± 0.03 day(-1)). The slower depuration rate of dcGTX2 + 3 in the heavily contaminated mussels at the laboratory may be related to a more effective contribution of C1 + 2 biotransformation.

  1. Amnesic shellfish poisoning biotoxin detection in seawater using pure or amino-functionalized Ag nanoparticles and SERS.

    Science.gov (United States)

    Müller, Csilla; Glamuzina, Branko; Pozniak, Iva; Weber, Karina; Cialla, Dana; Popp, Jürgen; Cîntă Pînzaru, Simona

    2014-12-01

    Domoic acid (DA) biotoxin responsible for the amnesic shellfish poisoning (ASP) has been unambiguously detected in seawater in a broad range of concentration, with both pure and amino-functionalized Ag nanoparticles employed for surface enhanced Raman scattering (SERS). To achieve this, a comprehensive SERS study on DA dissolved in distilled water has been conducted. SERS of DA dissolved in seawater in concentrations ranging from 3.3 × 10(-4) to 3.3 × 10(-8) mol l(-1) exhibited specific signal, completely different to those of the corresponding DA aqueous solutions, due to the seawater interference in the overall SERS effect. In order to assess the capability of the technique as a cheaper alternative for rapid and unambiguous detection of the DA biotoxin in seawater, three detection schemes have been proposed. DA was detectable at 0.33 nmoll(-1) concentration (0.33) dissolved in distilled water and 0.033 nmol l(-1) (0.033 ppb) in seawater respectively, much lower than the admitted level by the current regulation. A solvent specific interaction of DA with the NPs was concluded, since DA aqueous solution added to Ag nanoparticles provided different SERS signal compared to that of DA directly dissolved in seawater. Employing amino-functionalized Ag nanoparticles with 4-aminothiophenol as SERS tag, SERS signal of DA on amino-AgNPs revealed significant specificity associated with the aromatic primary amine interaction of the SERS tag with DA, thus allowing DA detection in seawater at 4.16 × 10(-4) mol l(-1) concentration, much higher than in the case of pure NPs. To highlight the findings, a brief literature review to date on the DA biotoxin detection was also provided. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Uptake, distribution and depuration of paralytic shellfish toxins from Alexandrium minutum in Australian greenlip abalone, Haliotis laevigata.

    Science.gov (United States)

    Dowsett, Natalie; Hallegraeff, Gustaaf; van Ruth, Paul; van Ginkel, Roel; McNabb, Paul; Hay, Brenda; O'Connor, Wayne; Kiermeier, Andreas; Deveney, Marty; McLeod, Catherine

    2011-07-01

    Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed pellets supplemented with 8 × 10⁵ Alexandrium minutum dinoflagellate cells g⁻¹ (containing 12 ± 3.0 μg STX-equivalent 100 g⁻¹, which was mainly GTX-1,4) every second day for 50 days. Exposure of abalone to PST supplemented feed for 50 days did not affect behaviour or survival but saw accumulation of up to 1.6 μg STX-equivalent 100 g⁻¹ in the abalone foot tissue (muscle, mouth without oesophagus and epipodial fringe), which is ∼50 times lower than the maximum permissible limit (80 μg 100 g⁻¹ tissue) for PSTs in molluscan shellfish. The PST levels in the foot were reduced to 0.48 μg STX-equivalent 100 g⁻¹ after scrubbing and removal of the pigment surrounding the epithelium of the epipodial fringe (confirmed by both HPLC and LC-MS/MS). Thus, scrubbing the epipodial fringe, a common procedure during commercial abalone canning, reduced PST levels by ∼70%. Only trace levels of PSTs were detected in the viscera (stomach, gut, heart, gonad, gills and mantle) of the abalone. A toxin reduction of approximately 73% was observed in STX-contaminated abalone held in clean water and fed uncontaminated food over 50 days. The low level of PST uptake when abalone were exposed to high numbers of A. minutum cells over a prolonged period may indicate a low risk of PSP poisoning to humans from the consumption of H. laevigata that has been exposed to a bloom of potentially toxic A. minutum in Australia. Further research is required to establish if non-dietary accumulation can result in significant levels of PSTs in abalone. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  3. Some notions on urbanity

    DEFF Research Database (Denmark)

    Grønlund, Bo

    According to International Federation of Housing and Planning the majority of the population of the planet will be urban in 2007. That definition of the urban, however, is based on zombie categories, to speak as Ulrich Beck. Urbanization and urban areas as we normally understand them are concepts...... of 'the first modernity'. Nowadays, in 'the second modernity', we have instead to aks: where in the city do you really find urbanity? A large part of what statistically is called urban areas lack urban quality and visible urban life. In the space syntax community urbanity is basically understood...

  4. First report of diarrheic shellfish toxins in mollusks from Buenos Aires province (Argentina associated with dinophysis spp.: evidence of okadaic acid, dinophysistoxin-1 and their acylderivatives

    Directory of Open Access Journals (Sweden)

    Eugenia A Sar

    2012-06-01

    Full Text Available In January 2010, the toxin-producing dinoflagellates Dinophysis acuminata and D. caudata (10³ cells·l-1 were detected in Mar Azul during routine plankton monitoring in Buenos Aires Province coastal waters, Argentina. Wild clams Mesodesma mactroides and Donax hanleyanus from Mar Azul intertidal beach, which are part of the diet for local inhabitants and tourists, tested positive with the offcial lipophilic mouse bioassay. This paper focuses on the detection of Diarrhetic Shellfsh Poison (DSP toxins in these samples using a HPLC-FLD pre column derivatization procedure. The data showed that shellfish were contaminated with complex DSP toxin profiles composed of Okadaic Acid (OA, Dinophysistoxin-1 (DTX-1, Acyl-Dinophysistoxin-1 (Acyl-DTX-1 and Acyl-Okadaic Acid (Acyl-OA. The DSP toxins found in this study produce diarrhea symptoms consistent with those experienced by patients who had ingested cooked shellfish in January. This is the first report of Acyl-derivatives in South American Atlantic shellfish samples and of OA in Argentinean shellfish samples.Primer reporte de toxinas diarreicas de moluscos en bivalvos de la Provincia de Buenos Aires (Argentina asociado con Dinophysis spp.: evidencia de Ácido Okadaico, Dinophysistoxina-1 y sus acyl-derivados. En enero de 2010, los dinoflagelados productores de toxinas Dinophysis acuminata y D. caudata (10³ cells·l-1 fueron detectados en Mar Azul durante un monitoreo rutinario de fitoplancton realizado en aguas costeras de la Provincia de Buenos Aires, Argentina. Mesodesma mactroides (almeja amarilla y Donax hanleyanus (berberecho del intermareal de Mar Azul, que son parte de la dieta de los habitantes del lugar y de turistas, dieron resultado positivo para toxinas lipofílicas mediante bioensayo ratón. Este trabajo está focalizado en la detección de Toxinas Diarreicas de Moluscos (DSP en muestras colectadas durante el evento de toxicidad usando un HPLC-FLD con procedimiento de derivatizaci

  5. Urban acupuncture

    CERN Document Server

    Lerner, Jaime

    2014-01-01

    During his three terms as mayor of Curitiba, Brazil in the 1970s and ‘80s, architect and urbanist Jaime Lerner transformed his city into a global model of the sustainable and livable community. Through his pioneering work, Lerner has learned that changes to a community don’t need to be large-scale and expensive to have a transformative impact—in fact, one block, park or a single person can have an outsized effect on life in the surrounding city. In Urban Acupuncture, his first work published in English, Lerner celebrates these “pinpricks” of urbanism—projects, people and initiatives from around the world that ripple through their communities to uplift city life. With meditative and descriptive prose, Lerner brings readers around the world to streets and neighborhoods where urban acupuncture has been practiced best, from the bustling La Boqueria market in Barcelona to the revitalization of the Cheonggyecheon River in Seoul, South Korea. Through this journey, Lerner invites us to re-examine the true...

  6. Urban Agriculture Guide

    NARCIS (Netherlands)

    Visser, A.J.; Jansma, J.E.; Dekking, A.J.G.; Klieverik, M.J.M.

    2007-01-01

    The Urban Agriculture Guide describes the experiences, learning moments, tips and tricks of those involved in the initiatives of urban agriculture and an indication is provided of what is required to develop urban agriculture further in the Netherlands

  7. : Urban design, urban project, urban art, urban composition ... a question of vocabulary?

    OpenAIRE

    Pinson , Daniel

    2014-01-01

    Actes à paraître; International audience; The term "urbanism" of Pierre Clerget (1910) put the mess in the practice and the formations in France. Urban planning is thus, on the academic level, a coexistence of disciplinary approaches, which does not help to a multidisciplinary urban training. Thinking about "urban design", after beautifull city, urban composition, or alongside the urban project and other territorial approaches can help to see more clearly in town planning.; Le terme « urbanis...

  8. EVALUATION OF URBANIZATION INFLUENCES ON URBAN ...

    African Journals Online (AJOL)

    Osondu

    2012-07-27

    Jul 27, 2012 ... direction greatly affects dispersion of pollutants in the city and distribution of heat which affect human comfort. ... The urbanization is evidenced by the reducing urban land surface reflectivity and the ..... Government Print Press.

  9. Urban biomass - not an urban legend

    Science.gov (United States)

    Utilizing biomass from urban landscapes could significantly contribute to the nation’s renewable energy needs. There is an estimated 16.4 million hectares of land in urban areas cultivated with turfgrass and associated vegetation. Vegetation in urban areas is intensely managed which lead to regula...

  10. Radioactive contamination of fish, shellfish, and waterfowl exposed to Hanford effluents: Annual summaries, 1945--1972. Hanford Environmental Dose Reconstruction Project

    Energy Technology Data Exchange (ETDEWEB)

    Hanf, R.W.; Dirkes, R.L.; Duncan, J.P.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction Project (HEDR) is to estimate the potential radiation doses received by people living within the sphere of influence of the Hanford Site. A potential critical pathway for human radiation exposure is through the consumption of waterfowl that frequent onsite waste-water ponds or through eating of fish, shellfish, and waterfowl that reside in/on the Columbia River and its tributaries downstream of the reactors. This document summarizes information on fish, shellfish, and waterfowl radiation contamination for samples collected by Hanford monitoring personnel and offsite agencies for the period 1945 to 1972. Specific information includes the types of organisms sampled, the kinds of tissues and organs analyzed, the sampling locations, and the radionuclides reported. Some tissue concentrations are also included. We anticipate that these yearly summaries will be helpful to individuals and organizations interested in evaluating aquatic pathway information for locations impacted by Hanford operations and will be useful for planning the direction of future HEDR studies.

  11. Optimizing a method for detection of hepatitis A virus in shellfish and study the effect of gamma radiation on the viral genome

    International Nuclear Information System (INIS)

    Amri, Islem

    2008-01-01

    Our work was aimed at detecting the hepatitis A virus (HAV) in bivalve mollusc collected from five shellfish harvesting areas and from a coastal region in Tunisia using RT-Nested-PCR and studying the effect of gamma radiation on HAV genome. Two methods used to recover HAV from mollusc flesh and two methods of extraction of virus RNA were compared in order to determine the most sensitive method. Glycine extraction and extraction of virus RNA using proteinase K were more convenient and then used in this study for detection of HAV in shellfish. The results of molecular analyses: RT-Nested-PCR using primers targeted at the P1 region revealed that 28 % of the samples were positive for HAV. Doses of gamma irradiation ranging between 5 to 30 kGy were used to study the effect of this radiation on HAV genome after the contamination of mollusc flesh with suspension of HAV (derived from stool specimens). HAV specific genomic band was observed for doses between 5 to 20 kGy. We didn't detect HAV genome with doses 25 and 30 kGy. (Author)

  12. Sustaining Urban Forests

    Science.gov (United States)

    John F. Dwyer; David J. Nowak

    2003-01-01

    The significance of the urban forest resource and the powerful forces for change in the urban environment make sustainability a critical issue in urban forest management. The diversity, connectedness, and dynamics of the urban forest establish the context for management that will determine the sustainability of forest structure, health, functions, and benefits. A...

  13. Exercises in Urban Reconnaissance

    Directory of Open Access Journals (Sweden)

    Lorenzo Tripodi

    2016-03-01

    Full Text Available Exercises in Urban Reconnaissance is a toolbox to examine and disentangle urban complexities. Not the city, not the urban territory, not the urbanization process but the irreducible condition produced by the dialectical relation and the semantic stratification resulting from these factors.

  14. Amnesic Shellfish Poisoning

    Science.gov (United States)

    ... Since then, the death or stranding of other marine animals, including whales, has been suspected or confirmed to ... sickened or die due to domoic acid poisoning. Animals poisoned by domoic acid include seabirds and marine mammals, including sea lions, sea otters, whales. Domoic- ...

  15. Molluscan shellfish farming

    National Research Council Canada - National Science Library

    Spencer, B. E

    2002-01-01

    .... Some of the other chapters, describing the cultivation of bivalve larvae, on-growing of hatchery-reared oyster and clam spat, and site selection were co-authored and based on the authors' experiences...

  16. Luminescence detection of shellfish

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Carmichael, L.A.; Spencer, J.Q.; Naylor, J.D.

    1996-01-01

    The Scottish Universities Research and Reactor Centre (SURRC) has been active in the development and application of luminescence techniques in the detection of irradiated foods, in support of UK legislation. Thermoluminescence (TL), photostimulated luminescence (PSL) and photo-transfer luminescence (PTTL) are radiation-specific phenomena which arise due to energy stored by trapped charge carriers following irradiation. The energy released following stimulation is accompanied by detectable luminescence. The TL method involves preparation of pure silicate extracts from the sample and subsequent TL analysis, whereas PSL uses stimulation by electromagnetic radiation (visible, or near visible wavelengths) thus avoiding heating the sample. (author)

  17. Buying, Preparing, and Cooking Shellfish. Learning Activity Pack and Instructor's Guide 5.13c. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    Science.gov (United States)

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with the various market forms of shellfish and how to clean, prepare, and cook them. Illustrated information sheets and learning activities are provided in these…

  18. Introduction to Fish and Shellfish. Learning Activity Pack and Instructor's Guide 5.13a. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    Science.gov (United States)

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with fish and shellfish for restaurant use. Illustrated information sheets and learning activities are provided in these areas: buying and storing fish and…

  19. Urban forests for sustainable urban development

    Science.gov (United States)

    Sundara, Denny M.; Hartono, Djoko M.; Suganda, Emirhadi; Haeruman, S. Herman J.

    2017-11-01

    This paper explores the development of the urban forest in East Jakarta. By 2030 Jakarta area has a target of 30% green area covering 19,845 hectares, including urban forest covering an area of 4,631 hectares. In 2015, the city forest is only 646 hectares, while the city requires 3,985 hectares of new land Urban forest growth from year to year showed a marked decrease with increasing land area awoke to commercial functions, environmental conditions encourage the development of the city to become unsustainable. This research aims to support sustainable urban development and ecological balance through the revitalization of green areas and urban development. Analytical methods for urban forest area is calculated based on the amount of CO2 that comes from people, vehicles, and industrial. Urban spatial analysis based on satellite image data, using a GIS program is an analysis tool to determine the distribution and growth patterns of green areas. This paper uses a dynamic system model to simulate the conditions of the region against intervention to be performed on potential areas for development of urban forests. The result is a model urban forest area is integrated with a social and economic function to encourage the development of sustainable cities.

  20. Laurus nobilis, Zingiber officinale and Anethum graveolens Essential Oils: Composition, Antioxidant and Antibacterial Activities against Bacteria Isolated from Fish and Shellfish.

    Science.gov (United States)

    Snuossi, Mejdi; Trabelsi, Najla; Ben Taleb, Sabrine; Dehmeni, Ameni; Flamini, Guido; De Feo, Vincenzo

    2016-10-22

    Several bacterial strains were isolated from wild and reared fish and shellfish. The identification of these strains showed the dominance of the Aeromonas hydrophila species in all seafood samples, followed by Staphylococcus spp., Vibrio alginolyticus , Enterobacter cloacae , Klebsiella ornithinolytica , Klebsiella oxytoca and Serratia odorifera . The isolates were studied for their ability to produce exoenzymes and biofilms. The chemical composition of the essential oils from Laurus nobilis leaves, Zingiber officinale rhizomes and Anethum graveolens aerial parts was studied by GC and GC/MS. The essential oils' antioxidant and antibacterial activities against the isolated microorganisms were studied. Low concentrations of the three essential oils were needed to inhibit the growth of the selected bacteria and the lowest MBCs values were obtained for the laurel essential oil. The selected essential oils can be used as a good natural preservative in fish food due to their antioxidant and antibacterial activities.

  1. Laurus nobilis, Zingiber officinale and Anethum graveolens Essential Oils: Composition, Antioxidant and Antibacterial Activities against Bacteria Isolated from Fish and Shellfish

    Directory of Open Access Journals (Sweden)

    Mejdi Snuossi

    2016-10-01

    Full Text Available Several bacterial strains were isolated from wild and reared fish and shellfish. The identification of these strains showed the dominance of the Aeromonas hydrophila species in all seafood samples, followed by Staphylococcus spp., Vibrio alginolyticus, Enterobacter cloacae, Klebsiella ornithinolytica, Klebsiella oxytoca and Serratia odorifera. The isolates were studied for their ability to produce exoenzymes and biofilms. The chemical composition of the essential oils from Laurus nobilis leaves, Zingiber officinale rhizomes and Anethum graveolens aerial parts was studied by GC and GC/MS. The essential oils’ antioxidant and antibacterial activities against the isolated microorganisms were studied. Low concentrations of the three essential oils were needed to inhibit the growth of the selected bacteria and the lowest MBCs values were obtained for the laurel essential oil. The selected essential oils can be used as a good natural preservative in fish food due to their antioxidant and antibacterial activities.

  2. Effects of sewage contamination on macro-algae and shellfish at Moa Point, New Zealand, using stable carbon and nitrogen isotopes

    International Nuclear Information System (INIS)

    Rogers, K.M.

    1999-01-01

    Stable carbon and nitrogen isotopes have been used to characterise sewage discharge and effects on seaweed (Ulva lactuca L.), blue mussels (Mytilus galloprovincialis), and limpets (Cellana denticulata) from Moa Point Bay, New Zealand. The nitrogen ( 15 N / 14 N) ratio is shown to be a good tracer of sewage pollution in Ulva lactuca and associated grazers (Cellana denticulata) as a result of the increased contribution of urea and ammonia to the surrounding marine environment from the sewage outfall. The carbon ( 13 C / 12 C) ratio is suggested as a more appropriate sewer tracer for mussels (Mytilus galloprovincialis), which filter feed the particulate organic matter from the effluent. Lower carbon : nitrogen ratios were found in U. lactuca sampled from the outfall region, compared to uncontaminated control sites, however carbon : nitrogen ratios do not vary significantly amongst shellfish species. (author). 18 refs., 4 figs., 2 tabs

  3. Detection of Salmonella in Shellfish Using SYBR Green™ I-Based Real-Time Multiplexed PCR Assay Targeting invA and spvB

    KAUST Repository

    Gangwar, Maulshree; Waters, Alicia M.; Bej, Gautam A.; Bej, Asim K.; Mojib, Nazia

    2012-01-01

    A SYBR Green™ I-based real-time multiplexed PCR assay was developed targeting invA and spvB for the detection of Salmonella strains in shellfish after both hns and invA genes were identified in all Salmonella strains. Simultaneously, the 16S rRNA gene was used as a PCR internal amplification control (IAC). All 89 Salmonella strains tested in this study exhibited amplification of invA, whereas only 21 (23. 6 %) were PCR positive for spvB. The sensitivity of detection of all three targeted genes was 1 ng, which is equivalent to approximately 105 colony-forming unit (CFU) of Salmonella enterica. The analysis showed specific PCR products that were identified by reproducible melt temperature profiles (invA, 84. 27 ± 1. 7 °C; spvB, 88. 76 ± 1. 0 °C; and 16S rRNA gene, 87. 16 ± 0. 8 °C). The sensitivity of detection was 10 pg purified DNA (invA) or 105 CFU in 1 mL pure culture of S. enterica ATCC 14028. The above molecular detection method for Salmonella strains was successfully applied to the oyster homogenates (food matrix). An initial inoculum of 106 and 102 CFU Salmonella in 1 ml seeded oyster tissue homogenate was detected by multiplexed PCR for all three genes after 5 and 24 h of enrichment, respectively. Natural oysters isolated from Gulf of Mexico during the winter months exhibited negative PCR amplification results suggesting the absence of Salmonella. In contrast to conventional PCR, real-time multiplex PCR assay developed in this study is rapid and sensitive and will help Interstate Shellfish Sanitation Conference undertake appropriate measures to monitor Salmonella in oysters, thereby preventing disease outbreaks and consequently protecting consumer health. © 2012 Springer Science+Business Media, LLC.

  4. Resource use of an aquacultured shellfish in the reverse estuary Bahía San Quintín, Baja California, México

    Science.gov (United States)

    Wilkinson, G. M.; Emery, K.; Camacho-Ibar, V.; Pace, M.; McGlathery, K.; Sandoval Gil, J.; Hernandez-Lopez, J.

    2016-02-01

    Shellfish aquaculture is prominent in many coastal and estuarine environments. Filter feeding by cultured shellfish connects the benthic and pelagic environments in coastal ecosystems. Bahía San Quintín is a reverse estuary in Baja California, Mexico, where Pacific oysters (Crassostrea gigas) are cultivated. While oysters likely feed heavily on phytoplankton especially during upwelling periods, we hypothesized that other forms of organic matter available in high quantities such as seagrass (Zostera marina) and macroalgae (Ulva spp.) must also be used by the oysters, especially in the most inshore portions of the bay. We measured the carbon and hydrogen stable isotope composition of oysters and their potential food resources at upper, mid, and lower bay sites during upwelling and non-upwelling seasons and applied a Bayesian mixing model to evaluate resource use. Hydrogen isotopes provided a large separation between potential food resources. Although we did not find any strong seasonal effects due to upwelling, there was a strong spatial gradient in resource use. Phytoplankton were most important at the lower (oceanic) site (median resource use for two sampling times, 68 and 79 %) and decreased up the estuary as macroalgae became more important (43 and 56 % at the upper site). At all sites for both sampling times, seagrass was an unimportant resource for oysters. The contrast between high phytoplankton use at the lower site and increased macroalgal use at the upper site is likely due to available resource biomass. Our results illustrate the adaptability of oysters to varying resource availability and the possibility of a higher system carrying capacity than that based on phytoplankton alone given multiple potential food sources.

  5. Detection of Salmonella in Shellfish Using SYBR Green™ I-Based Real-Time Multiplexed PCR Assay Targeting invA and spvB

    KAUST Repository

    Gangwar, Maulshree

    2012-09-23

    A SYBR Green™ I-based real-time multiplexed PCR assay was developed targeting invA and spvB for the detection of Salmonella strains in shellfish after both hns and invA genes were identified in all Salmonella strains. Simultaneously, the 16S rRNA gene was used as a PCR internal amplification control (IAC). All 89 Salmonella strains tested in this study exhibited amplification of invA, whereas only 21 (23. 6 %) were PCR positive for spvB. The sensitivity of detection of all three targeted genes was 1 ng, which is equivalent to approximately 105 colony-forming unit (CFU) of Salmonella enterica. The analysis showed specific PCR products that were identified by reproducible melt temperature profiles (invA, 84. 27 ± 1. 7 °C; spvB, 88. 76 ± 1. 0 °C; and 16S rRNA gene, 87. 16 ± 0. 8 °C). The sensitivity of detection was 10 pg purified DNA (invA) or 105 CFU in 1 mL pure culture of S. enterica ATCC 14028. The above molecular detection method for Salmonella strains was successfully applied to the oyster homogenates (food matrix). An initial inoculum of 106 and 102 CFU Salmonella in 1 ml seeded oyster tissue homogenate was detected by multiplexed PCR for all three genes after 5 and 24 h of enrichment, respectively. Natural oysters isolated from Gulf of Mexico during the winter months exhibited negative PCR amplification results suggesting the absence of Salmonella. In contrast to conventional PCR, real-time multiplex PCR assay developed in this study is rapid and sensitive and will help Interstate Shellfish Sanitation Conference undertake appropriate measures to monitor Salmonella in oysters, thereby preventing disease outbreaks and consequently protecting consumer health. © 2012 Springer Science+Business Media, LLC.

  6. [Can solar/geomagnetic activity restrict the occurrence of some shellfish poisoning outbreaks? The example of PSP caused by Gymnodinium catenatum at the Atlantic Portuguese coast].

    Science.gov (United States)

    Vale, P

    2013-01-01

    Cyclic outbreaks of accumulation of paralytic shellfish poisoning (PSP) toxins in mussels attributed to Gymnodinium catenatum blooms displayed several of the highest inter-annual maxima coincidental with minima of the 11-year solar sunspot number (SSN) cycle. The monthly distribution of PSP was associated with low levels of the solar radio flux, a more quantitative approach than SSN for fluctuations in solar activity. A comparison between monthly distribution of PSP and other common biotoxins (okadaic acid (OA), dinophysistoxin-2 (DTX2) and amnesic shellfish poisoning (ASP) toxins) demonstrated that only PSP was significantly associated with low levels of radio flux (p < 0.01). PSP occurrence suggests a prior decline in solar activity could be required to act as a trigger, in a similar manner to a photoperiodic signal. The seasonal frequency increased towards autumn during the study period, which might be related to the progressive atmospheric cut-off of deleterious radiation associated with the seasonal change in solar declination, and might play an additional role in seasonal signal-triggering. PSP distribution was also associated with low levels of the geomagnetic index Aa. A comparison between monthly distribution of PSP and other common biotoxins, also demonstrated that only PSP was significantly associated with low levels of the Aa index (p < 0.01). In some years of SSN minima no significant PSP-outbreaks in mussels were detected. This was attributed to a steady rise in geomagnetic activity that could disrupt the triggering signal. Global distribution patterns show that hotspots for G. catenatum blooms are regions with deficient crustal magnetic anomalies. In addition to the variable magnetic field mostly of solar origin, static fields related to magnetized rocks in the crust and upper mantle might play a role in restricting worldwide geographic distribution.

  7. Urban Greening Bay Area

    Science.gov (United States)

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  8. Urban growth management

    DEFF Research Database (Denmark)

    Jørgensen, Gertrud; Alexander Sick Nielsen, Thomas; Grünfelder, Julien

    2011-01-01

    , and finally urban attractivity policies. Effective regional bodies are needed to deal with urban expansion and peri-urbanisation at a relevant scale; European rural and agricultural policies makes up the main ‘policy complex’ targeting the non-urban area including its land uses; while lastly leverage of urban...... urban growth and curb urban sprawl in a wider sense. Methodology The main methodology of the paper is a desk-research based review of policy options supplemented with field study and interviews in selected cased study regions. This paper consists of two parts. The first part is based on literature...... there are contradictions in the evidence presented in the literature, we believe that it may be safely said that urban growth management policies have an influence on urban growth under certain preconditions including: sufficient time for implementation and continuity of efforts; choice of appropriate policy measures...

  9. Urban mental health

    DEFF Research Database (Denmark)

    Okkels, Niels; Kristiansen, Christina Blanner; Munk-Jørgensen, Povl

    2018-01-01

    . Fast and unstructured urbanization, such as that seen in many developing countries, further exacerbates these challenges. There are promising initiatives emerging including initiatives to end homelessness, to improve access to green areas in urban environments, to provide emergency psychiatric services...

  10. Performative Urban Design

    DEFF Research Database (Denmark)

    Samson, Kristine

    2011-01-01

    visitors and participants to engage and interact with the city. Inspired by Lefebvre statement that "the most beautiful cities were those where festivals were not planned in advance” (Lefebvre 1987:36), I will discuss how urban designers can design engaging spaces, where the potentials of the city can...... unfold. Is it, for instance, the formal aesthetics of the design or rather the socio-cultural codes of the existing urban space that engage people? The paper engages in three urban performance designs: 1) The 10th Avenue Plaza at the Highline in New York 2) The temporary installations at Boble Plads......Urban design has come to mean many things. From the architectural masterplans to the informal urban design in temporary spaces and event designs. The paper will focus on urban designs engaging urban designs. Engaging urban design can broadly be understood as temporary design installations inviting...

  11. African Urban Harvest

    International Development Research Centre (IDRC) Digital Library (Canada)

    Urban Harvest, a system-wide initiative of the Consultative Group on Agricultural ...... and urban old, using criteria of population density, land availability, and the prevalence of crop ...... Contact between milk and containers or the environment;.

  12. Urban restrukturering og byidentitet

    DEFF Research Database (Denmark)

    Kvorning, Jens

    2002-01-01

    Bidrag til publikationen i forbindelse med EU-konference samt uddrag af forskningsprojektet: Urban restrukturering......Bidrag til publikationen i forbindelse med EU-konference samt uddrag af forskningsprojektet: Urban restrukturering...

  13. Nonpoint Source: Urban Areas

    Science.gov (United States)

    Urbanization increases the variety and amount of pollutants carried into our nation's waters. Pavement and compacted landscapes do not allow rain and snow melt to soak into the ground. List of typical pollutants from Urban runoff.

  14. Urban Waters Partnership

    Science.gov (United States)

    Includes information on 14 Federal member agencies for the Urban Waters Federal Partnership and 19 designated urban waters locations and the local stakeholder groups and activities. Content was formerly at www.epa.gov/urbanwaters/

  15. Parametrics in Urban Design

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Obeling, Esben

    2013-01-01

    The design of urban space has always been contested. Whether imposed by autocratic rulers, emerged as a result of market forces, or implemented as a result of democratic planning processes, urban space design shapes the lives of urban dwellers. Yet rarely does the average urban dweller have any r...... implementation by means of CityEngine is given and discussed with respect to it pros and cons. And finally, the potential implications of this approach are touched as an outline for further research....

  16. The Urbanism of Material

    OpenAIRE

    LAURA MARY HARPER

    2018-01-01

    This thesis investigates how the urban environment is constructed over time. The aim of this research is to understand the relationship between the decisions, logic and methods used at the scale of an individual site to the wider organisation and form of the urban environment. The thesis draws on the concept of bottom up systems to investigate ideas of collective organisation and characteristics in the urban environment. Using a series of architectural and urban case studies in Melbourne and ...

  17. New urban theory

    DEFF Research Database (Denmark)

    Grønlund, Bo

    2002-01-01

    Concept of urbanity, urban theory a short overview, Johan Asplund, William Whyte, Henri Lefebvre, Richard Serenelt, Bill Hillrer and Spree Syntax Analyses. Forelæsningsnoter til kursus 3.314 i 2001 og 3.308 i 2002.......Concept of urbanity, urban theory a short overview, Johan Asplund, William Whyte, Henri Lefebvre, Richard Serenelt, Bill Hillrer and Spree Syntax Analyses. Forelæsningsnoter til kursus 3.314 i 2001 og 3.308 i 2002....

  18. the urban jungle

    African Journals Online (AJOL)

    One of the most significant problems facing urban communities today is the ... attempts to address such an ethic. THE URBAN ... (a) picture building; (b) problem solving; and (c) action taking. ... need to develop critical thinking and problem-solving skills. The urban ... environment is regarded as important by the school, and ...

  19. China's Urban Transition.

    Science.gov (United States)

    Pannell, Clifton

    1995-01-01

    Maintains that Chinese urbanization is proceeding rapidly in step with population growth and a structural shift in employment patterns. Discusses governmental policies and economic reforms that enhance the urbanization process. Describes four extended metropolitan areas and maintains they will be the models for future urbanization. (CFR)

  20. Housing consumption and urbanization

    OpenAIRE

    Lozano-Gracia, Nancy; Young, Cheryl

    2014-01-01

    Rapid urbanization in Sub-Saharan Africa places immense pressure on urban services to meet the needs of the burgeoning urban population. Although several country- or city-level reports offer insight into the housing challenges of specific places, little is known about regional patterns affecting housing markets. This lack of clear knowledge on the relative importance of the factors influen...

  1. Urban Sound Ecologies

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh; Samson, Kristine

    2013-01-01

    . The article concludes that the ways in which recent sound installations work with urban ecologies vary. While two of the examples blend into the urban environment, the other transfers the concert format and its mode of listening to urban space. Last, and in accordance with recent soundscape research, we point...

  2. Urban development in China

    NARCIS (Netherlands)

    Brakman, Steven; Garretsen, J.H.; van Marrewijk, J.G.M.

    2016-01-01

    Urbanization is important for economic development. As the largest country in the world in terms of population, China has experienced a remarkable history of urbanization; one 1000 years ago it housed the largest cities in world, it went through a counter-urbanization revolution during the Mao

  3. Urban Renewal as an Urban Hegemony Project

    Directory of Open Access Journals (Sweden)

    Gönül İÇLİ

    2012-01-01

    Full Text Available There is an organic relationship between capitalism and urban space. Thisrelationship is a dynamic one which reproduces and renovates itself constantlyaccording to the conjuncture of each period and which evolves / changes inparallel with the necessities and rationalities of capital accumulation in historicalprocess. Therefore, neither reproduction of capitalist urban space with the regimeof capital accumulation nor the process of restructuring following a crisis in theregime of capital accumulation with spatial organization of capitalism can becompared independently. Today, in the concrete phase that capitalism hasreached, urban space has become one of the most important parts of direct capitalaccumulation under the hegemony of financial capital. In this context, urbantransformation projects and various strategies ofthe process becomes significantwith the instrumentalization of space by capital rationality. However, this processcarries the internal paradoxes of capitalism into the urban space at the same time,and cities, competing as candidates to be financial centres where the capital hasintensified and centralized, also transforms into spaces of violent socialpolarization. At this point, especially the reformation of squatter settlements has astrategic importance in the process of urban transformation and there are attemptsto attach the urban poor, who are the addressee of the process, under a widerurban hegemony project with the strategy of urban renovation.

  4. Physical, chemical, marine fish, shellfish, and other data from bottle casts and bottom trawls from the JEFF AND TINA as part of the EPA/FLOWER GARDENS project from 1980-10-11 to 1981-07-27 (NODC Accession 8200169)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, marine fish, shellfish, and other data from bottle casts and bottom trawls from the JEFF AND TINA from 11 October 1980 to 27 July 1981. Data were...

  5. Sustainable urban environmental quality

    Directory of Open Access Journals (Sweden)

    Tošković Dobrivoje

    2004-01-01

    Full Text Available MEANING as the essential element of urban quality. The role of the three main factors for the urban quality achievement: PLANNING, DEVELOPMENT and PEOPLE. Next to that, it is important to assume the identity of the local CONTEXT as the essential base for designing and shaping of form development. The problems of the quality achievements in the situation of the permanent changes. In such an environment - the RENEWAL of the towns become the basic strategic orientation requiring - evaluation of the development policy instruments. On the road of changes there are PROBLEMS of a strategic nature which should be, firstly, defined and, then, solved before entering in the process of structuring and arrangement. One of these problems is NEW versus OLD. Transition to a new policy of urbanism relying, first of all, on the private investors and international funds of the local authorities - call for a NEW STRATEGY in urbanism, in the context of the sustainability of environment. The sustainability of quality and the categories of the influencing factors. The sustainability of quality as a twofold process of urban design. The quality of environment as an aesthetic phenomenon. The urban situation and environmental quality: feasibility of changes and effects; the environmental capacity as an indicator and quality determinant. The urban quality and international experience. The evaluation of our urban situation. INSTEAD OF CONCLUSION: A general review on the visions and urban quality policy and planning. Toward an evaluation of urban environmental quality: negative and positive indicators; sustainable communities environmental ruling and urban quality planning.

  6. Performative Urban Design

    DEFF Research Database (Denmark)

    Performative Urban Design seeks to identify emerging trends in urban design as they are reflected in the city's architecture and spatial design. A “cultural grafting” of the inner city is taking place; architecture and art are playing a crucial, catalytic role in urban development. On the one hand...... these issues through three perspectives: •Sense Architecture; •Place-Making; and •Urban Catalysts. The articles in this volume identify relevant theoretical positions within architecture, art, and urban strategies while demonstrating relevant concepts and methodological approaches drawn from practical......, this development has been rooted in massive investments in “corporate architecture.” On the other, cities themselves have invested heavily in new cultural centers and performative urban spaces that can fulfil the growing desire for entertainment and culture. The anthology Performative Urban Design addresses...

  7. Urban flood risk warning under rapid urbanization.

    Science.gov (United States)

    Chen, Yangbo; Zhou, Haolan; Zhang, Hui; Du, Guoming; Zhou, Jinhui

    2015-05-01

    In the past decades, China has observed rapid urbanization, the nation's urban population reached 50% in 2000, and is still in steady increase. Rapid urbanization in China has an adverse impact on urban hydrological processes, particularly in increasing the urban flood risks and causing serious urban flooding losses. Urban flooding also increases health risks such as causing epidemic disease break out, polluting drinking water and damaging the living environment. In the highly urbanized area, non-engineering measurement is the main way for managing urban flood risk, such as flood risk warning. There is no mature method and pilot study for urban flood risk warning, the purpose of this study is to propose the urban flood risk warning method for the rapidly urbanized Chinese cities. This paper first presented an urban flood forecasting model, which produces urban flood inundation index for urban flood risk warning. The model has 5 modules. The drainage system and grid dividing module divides the whole city terrain into drainage systems according to its first-order river system, and delineates the drainage system into grids based on the spatial structure with irregular gridding technique; the precipitation assimilation module assimilates precipitation for every grids which is used as the model input, which could either be the radar based precipitation estimation or interpolated one from rain gauges; runoff production module classifies the surface into pervious and impervious surface, and employs different methods to calculate the runoff respectively; surface runoff routing module routes the surface runoff and determines the inundation index. The routing on surface grid is calculated according to the two dimensional shallow water unsteady flow algorithm, the routing on land channel and special channel is calculated according to the one dimensional unsteady flow algorithm. This paper then proposed the urban flood risk warning method that is called DPSIR model based

  8. Urban landscape as palimpsest

    Directory of Open Access Journals (Sweden)

    Daniel-Gabriel Vâlceanu

    2014-12-01

    Full Text Available The current urban morphology and the identity building of the city construction can be designed as a palimpsest; the spatial development stages of urban systems represent the result of their evolution over time. The characteristics of urban palimpsest depend mainly on the emergent factors that influenced the territorial dynamics and the configuration of urban bodies. Urban life and its quality are directly influenced by spatial and temporal factors of the city evolution. For this reason the study aims to achieve a research to explain the concept of urban palimpsest and the current morphology of urban tissue because they are products of landscape transformations along the history. The current knowledge on urban palimpsest characteristics is very important and useful to plan the current and future evolution of urban systems. The case study presents a vast view on the history of spatial development and urban system as well as a dynamics of the landscape interconditioned by the elements of such development in the context of reference historical eras

  9. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk from European green crab invasion [v3; ref status: indexed, http://f1000r.es/4jf

    Directory of Open Access Journals (Sweden)

    Megan E Mach

    2014-10-01

    Full Text Available Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound’s shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD year-1 (2.8-64% losses, with additional processing and distribution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial

  10. Trading green backs for green crabs: evaluating the commercial shellfish harvest at risk to European green crab invasion [v2; ref status: indexed, http://f1000r.es/32t

    Directory of Open Access Journals (Sweden)

    Megan E Mach

    2014-03-01

    Full Text Available Nonnative species pose a threat to native biodiversity and can have immense impacts on biological communities, altering the function of ecosystems. How much value is at risk from high-impact invasive species, and which parameters determine variation in that value, constitutes critical knowledge for directing both management and research, but it is rarely available. We evaluated the value of the commercial shellfish harvest that is at risk in nearshore ecosystems of Puget Sound, Washington State, USA, from the invasive European green crab, Carcinus maenas. We assessed this value using a simple static ecological model combined with an economic model using data from Puget Sound’s shellfish harvest and revenue and the relationship between C. maenas abundance and the consumption rate of shellfish. The model incorporates a range in C. maenas diet preference, calories consumed per year, and crab densities. C. maenas is likely to prey on commercially harvested hardshell clams, oysters, and mussels, which would likely reduce additional revenue from processing and distribution, and the number of jobs associated with these fisheries. The model results suggest possible revenue losses of these shellfish ranging from $1.03-23.8 million USD (2.8-64% losses, with additional processing and distrubution losses up to $17.6 million USD and 442 job positions each year associated with a range of plausible parameter values. The broad range of values reflects the uncertainty in key factors underlying impacts, factors that are highly variable across invaded regions and so not knowable a priori. However, future research evaluating species invasions can reduce the uncertainty of impacts by characterizing several key parameters: density of individuals, number of arrivals, predation and competition interactions, and economic impacts. This study therefore provides direction for research to inform more accurate estimates of value-at-risk, and suggests substantial motivation

  11. Determination of Urban Thermal Characteristics on an Urban/Rural ...

    African Journals Online (AJOL)

    Determination of Urban Thermal Characteristics on an Urban/Rural Land Cover Gradient Using Remotely Sensed Data. ... an urbanization process and the urban heat island (UHI) phenomenon is known to significantly compromise urban environmental quality and has been linked to climate change and associated impacts.

  12. Low-level cadmium exposure in Toyama City and its surroundings in Toyama prefecture, Japan, with references to possible contribution of shellfish intake to increase urinary cadmium levels

    International Nuclear Information System (INIS)

    Yamagami, T.; Ezaki, T.; Moriguchi, J.; Fukui, Y.; Okamoto, S.; Ukai, H.; Sakurai, H.; Aoshima, K.; Ikeda, M.

    2006-01-01

    Objectives: This study was initiated to examine if exposure to cadmium (Cd) was high also outside of the previously identified Itai-itai disease endemic region in the Jinzu River basin in Toyama prefecture in Japan. Methods: Morning spot urine samples were collected in June-August 2004 from 651 adult women (including 535 never-smokers) in various regions in Toyama prefecture, and subjected to urinalyses for cadmium (Cd), α 1 -microglobulin (α 1 -MG), β 2 -microglobulin (β 2 -MG), N-acetyl-β-D-glucosaminidase (NAG), specific gravity (SG or sg) and creatinine (CR or cr). Three months later, the second urine samples were collected from those with elevated Cd in urine (e.g., ≥ 4 μg/g cr), together with answers to questionnaires on shellfish consumption. Results: The geometric mean (GM) Cd, α 1 -MG, β 2 -MG and NAG (after correction for CR) for the total participants were 2.0 μg/g cr, 2.4 mg/g cr, 104 μg/g cr and 2.8 units/g cr, respectively; further analysis with never-smoking cases only did not induce significant changes in these parameters. Analyses of the second urine samples from the high Cd subjects showed that there was substantial decrease (to about a half) in Cd in the 3-month period, and that the decrease was accompanied by reduction in α 1 -MG and NAG (β 2 -MG did not show elevation even in the first samples). The urinalysis results in combination with the results of the questionnaire survey suggest that the high urinary Cd was temporary and might be induced by intake of shellfish that is edible whole. Conclusions: The overall findings appear to suggest that Cd exposure in Toyama populations (outside of the Itai-itai disease endemic region) was at the levels commonly observed on the coast of the Sea of Japan, and that the Cd level in urine might be modified by the intake of some types of seafood. Further studies are necessary to elucidate the relation of urinary Cd with seafood intake

  13. Low-level cadmium exposure in Toyama City and its surroundings in Toyama prefecture, Japan, with references to possible contribution of shellfish intake to increase urinary cadmium levels

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, T. [Hokuriku Health Service Association, Toyama 930-0177 (Japan); Ezaki, T. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan); Moriguchi, J. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan); Fukui, Y. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan); Okamoto, S. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan); Ukai, H. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan); Sakurai, H. [Occupational Health Research and Development Center, Japan Industrial Safety and Health Association, Minato-ku, Tokyo 108-0014 (Japan); Aoshima, K. [Hagino Hospital, Fuchu-machi, Toyama 939-2723 (Japan); Ikeda, M. [Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472 (Japan)]. E-mail: ikeda@kyotokojohokenkai.or.jp

    2006-06-01

    Objectives: This study was initiated to examine if exposure to cadmium (Cd) was high also outside of the previously identified Itai-itai disease endemic region in the Jinzu River basin in Toyama prefecture in Japan. Methods: Morning spot urine samples were collected in June-August 2004 from 651 adult women (including 535 never-smokers) in various regions in Toyama prefecture, and subjected to urinalyses for cadmium (Cd), {alpha}{sub 1}-microglobulin ({alpha}{sub 1}-MG), {beta}{sub 2}-microglobulin ({beta}{sub 2}-MG), N-acetyl-{beta}-D-glucosaminidase (NAG), specific gravity (SG or sg) and creatinine (CR or cr). Three months later, the second urine samples were collected from those with elevated Cd in urine (e.g., {>=} 4 {mu}g/g cr), together with answers to questionnaires on shellfish consumption. Results: The geometric mean (GM) Cd, {alpha}{sub 1}-MG, {beta}{sub 2}-MG and NAG (after correction for CR) for the total participants were 2.0 {mu}g/g cr, 2.4 mg/g cr, 104 {mu}g/g cr and 2.8 units/g cr, respectively; further analysis with never-smoking cases only did not induce significant changes in these parameters. Analyses of the second urine samples from the high Cd subjects showed that there was substantial decrease (to about a half) in Cd in the 3-month period, and that the decrease was accompanied by reduction in {alpha}{sub 1}-MG and NAG ({beta}{sub 2}-MG did not show elevation even in the first samples). The urinalysis results in combination with the results of the questionnaire survey suggest that the high urinary Cd was temporary and might be induced by intake of shellfish that is edible whole. Conclusions: The overall findings appear to suggest that Cd exposure in Toyama populations (outside of the Itai-itai disease endemic region) was at the levels commonly observed on the coast of the Sea of Japan, and that the Cd level in urine might be modified by the intake of some types of seafood. Further studies are necessary to elucidate the relation of urinary Cd

  14. Winter-summer nutrient composition linkage to algae-produced toxins in shellfish at a eutrophic coastal lagoon (Óbidos lagoon, Portugal)

    Science.gov (United States)

    Pereira, Patrícia; Botelho, Maria João; Cabrita, Maria Teresa; Vale, Carlos; Moita, Maria Teresa; Gonçalves, Célia

    2012-10-01

    The current work examines the linkage of pronounced winter-summer fluctuations on the nutrient composition with phytoplankton assemblages and mussel toxicity produced by the presence of toxic dinoflagellates. The work was performed at the Óbidos lagoon, a coastal eutrophic ecosystem that is permanently connected to an area characterized by frequent upwelling episodes. The lagoon and adjoining coastal area exhibit recurrent incidents of diarrhetic and paralytic shellfish poisoning. The conclusions are based on: (1) inorganic and organic nutrients at five sites of the lower, middle and upper Óbidos lagoon, and inorganic nutrients at two sites of the adjacent coastal area; biannual campaigns were performed in winter and summer between 2006 and 2010; (2) phytoplankton assemblages at three sites of the lagoon (located at lower and upper areas) in winter and summer of 2009; (3) algae-derived toxicity of wild mussels from the lower lagoon and coastal area, on a 1-2 week time scale, over 2006 and 2009. Nutrient molar ratios in Óbidos lagoon contrast between winter and summer. The lower median ratios DIN:P (31 and 0.8) and Si:P (11 and 3.3) in summer reflect the excess of phosphate. Excess was mainly attributed to phosphorus regeneration in sediments of the upper lagoon with accentuated symptoms of eutrophication. Dissolved organic nitrogen and dissolved organic phosphorus were also higher in summer, particularly in this area. No significant winter-summer differences were recorded for nutrient ratios in the adjacent coastal area. Phytoplankton assemblages pointed to a winter-summer contrast characterized by a shift of non-siliceous-based phytoplankton to diatoms. The toxic dinoflagellate species (Gymnodinium catenatum, Dinophysis cf. acuminata and Dinophysis acuta), presumably imported from the adjacent coast following upwelling episodes in summer, were observed in the lower lagoon. In summer of the two surveyed years, toxins produced by dinoflagellates occurred in

  15. Separation of paralytic shellfish poisoning toxins on Chromarods-SIII by thin-layer chromatography with the Iatroscan (mark 5) and flame thermionic detection.

    Science.gov (United States)

    Indrasena, W M; Ackman, R G; Gill, T A

    1999-09-10

    Thin-layer chromatography (TLC) on Chromarods-SIII with the Iatroscan (Mark-5) and a flame thermionic detector (FTID) was used to develop a rapid method for the detection of paralytic shellfish poisoning (PSP) toxins. The effect of variation in hydrogen (H2) flow, air flow, scan time and detector current on the FTID peak response for both phosphatidylcholine (PC) and PSP were studied in order to define optimum detection conditions. A combination of hydrogen and air flow-rates of 50 ml/min and 1.5-2.0 l/min respectively, along with a scan time of 40 s/rod and detector current of 3.0 A (ampere) or above were found to yield the best results for the detection of PSP compounds. Increasing the detector current level to as high as 3.3 A gave about 130 times more FTID response than did flame ionization detection (FID), for PSP components. Quantities of standards as small as 1 ng neosaxitoxin (NEO), 5 ng saxitoxin (STX), 5 ng B1-toxins (B1), 2 ng gonyautoxin (GTX) 2/3, 6 ng GTX 1/4 and 6 ng C-toxins (C1/C2) could be detected with the FTID. The method detection limits for toxic shellfish tissues using the FTID were 0.4, 2.1, 0.8 and 2.5 micrograms per g tissue for GTX 2/3, STX, NEO and C toxins, respectively. The FTID response increased with increasing detector current and with increasing the scan time. Increasing hydrogen and air flow-rates resulted in decreasing sensitivity within defined limits. Numerous solvent systems were tested, and, solvent consisting of chloroform: methanol-water-acetic acid (30:50:8:2) could separate C toxins from GTX, which eluted ahead of NEO and STX. Accordingly, TLC/FTID with the Iatroscan (Mark-5) seems to be a promising, relatively inexpensive and rapid method of screening plant and animal tissues for PSP toxins.

  16. Whole genome mRNA transcriptomics analysis reveals different modes of action of the diarrheic shellfish poisons okadaic acid and dinophysis toxin-1 versus azaspiracid-1 in Caco-2 cells.

    Science.gov (United States)

    Bodero, Marcia; Hoogenboom, Ron L A P; Bovee, Toine F H; Portier, Liza; de Haan, Laura; Peijnenburg, Ad; Hendriksen, Peter J M

    2018-02-01

    A study with DNA microarrays was performed to investigate the effects of two diarrhetic and one azaspiracid shellfish poison, okadaic acid (OA), dinophysistoxin-1 (DTX-1) and azaspiracid-1 (AZA-1) respectively, on the whole-genome mRNA expression of undifferentiated intestinal Caco-2 cells. Previously, the most responding genes were used to develop a dedicated array tube test to screen shellfish samples on the presence of these toxins. In the present study the whole genome mRNA expression was analyzed in order to reveal modes of action and obtain hints on potential biomarkers suitable to be used in alternative bioassays. Effects on key genes in the most affected pathways and processes were confirmed by qPCR. OA and DTX-1 induced almost identical effects on mRNA expression, which strongly indicates that OA and DTX-1induce similar toxic effects. Biological interpretation of the microarray data indicates that both compounds induce hypoxia related pathways/processes, the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress. The gene expression profile of AZA-1 is different and shows increased mRNA expression of genes involved in cholesterol synthesis and glycolysis, suggesting a different mode of action for this toxin. Future studies should reveal whether identified pathways provide suitable biomarkers for rapid detection of DSPs in shellfish. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Analysis of banned veterinary drugs and herbicide residues in shellfish by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and gas chromatography-tandem mass spectrometry (GC/MS/MS)

    International Nuclear Information System (INIS)

    Chang, Geng-Ruei; Chen, Hui-Shan; Lin, Feng-Yi

    2016-01-01

    Seafood safety is a crucial public health concern for consumers. In this study, we applied a validated method to analyze the residue of banned veterinary drugs in shellfish, namely chloramphenicol, malachite green, leucomalachite green, and nitrofuran metabolites; additionally, the QuEChERS method was employed to detect 76 herbicides by LC/MS/MS and GC/MS/MS. In total, 42 shellfish samples, which included hard clams, freshwater clams, and oysters, were collected from aquafarms and production areas in Taiwan during 2012. Our results revealed 3.8 ng/g of chloramphenicol in one hard clam, 19.9–32.1 ng/g of ametryn in two hard clams, 16.1–60.1 ng/g of pendimethalin in four hard clams, and 17.0 ng/g of mefenacet in one oyster, indicating that 19.1% of the samples contained residues from banned veterinary drugs and pesticides. These data can be used to monitor the residue of veterinary drugs and pesticides in aquatic organisms and as a reference for food safety. - Highlights: • A certified method was employed for analyzing residues of banned veterinary drugs and herbicides in shellfish samples. • The trace levels of chloramphenicol, ametryn, pendimethalin were detected in hard clam samples. • For ensuring food safety, continual monitoring of aquatic products is necessary.

  18. Urban Knowledge Arena

    Directory of Open Access Journals (Sweden)

    Karel Schmeidler

    2008-01-01

    Full Text Available COST Action C20 – Urban Knowledge Arena is research programme supported by European Co-operation in the Field of Scientific and Technical Research. It is co-ordinated by COST Office and European Science Foundation. The main objective of this Action is to explore and develop a European Arena for cross boundary, integrated knowledge and Know-how on complex urban problems, which is termed Urban Knowledge Arena. The COST Domain Transport and Urban Development aims at fostering international research networking activities of scientist and experts dealing with transport systems and infrastructures, spatial planning, urban land use and development, urban design, architecture and design and civil engineering issues. The focus is on multi and interdisciplinary approaches and the aim is to cover both basic and applied research activities and their changeovers that are relevant to policy and decision making processes. A significant concern is devoted to activities exploring new research needs and developments.

  19. UrbanTransformation

    DEFF Research Database (Denmark)

    Laursen, Lea Louise Holst

    Due to the economical and political changes marked by globalization, neo-liberalism and, post-industrialism a changed spatial configuration is emerging in which an increased division is taking place, into on the one hand, economical and demographical growing urban areas, where the urban fabric...... is being concentrated, and on the other, into declining urban areas that experience a dilution of the urban fabric and a de-concentration of people and capital. This gives an uneven spatial geography where some places are becoming nodal points in the global society and others are left behind. But the urban...... situation of concentration and de-concentration is also closely connected where there is a dynamic relation between the two. Decline might in some cases even be seen as an aspect of growth, where the growth of some places influence the decline in others. With this approach the urban fabric can, therefore...

  20. Urban Transport and Communication

    International Nuclear Information System (INIS)

    Irandu, E.M.

    1999-01-01

    The population according to the 1989 census was 21,448,774 inhabitants. This figure shows that on average the total population has been increasing by more than 40% every decade since 1948. As a result the widening gap between fertility and mortality, the population is growing at an accelerated rate. The current official population growth rate figure of 3.4% per annum puts the country among the world's most rapidly growing nations. It is projected that by the year 2010, the population will be about 37.4 million. At present the urban centres with a population size of 2,000 people and above constitute about 18.1% of the total population (Kenya, 1994). Rapid economic growth has led to the development of a number of urban centres as centres of commerce, industry and tourism. Consequently, this has led to rural urban drift. This drift to urban areas causes a number of problems which if unresolved will limit the ability of the urban centres to support their population The rapid increase in urban population causes a shortage of facilities to meet the increasing demand in services such as public transport, water supply, sewage and housing (Ramatullah, 1997: 161-168). Urban Transport acts as catalyst to both urban and national development, by facilitating the movements associated with urban and national Development. They provide a means by which goods and services are made available to industry and consumers, creating opportunity for social and economic interaction and employment. Without urban transport, access to health, education and employment would not be possible. Indeed urban transport is what gives life to urban development

  1. Urbanism Studio 2014

    DEFF Research Database (Denmark)

    This catalogue showcases the master Urbanism Studio results 2014, which have been developed utilising research on station cities completed by Centre for Strategic Urban Research. Together with the Ministry of Housing, Urban and Rural Affairs (MHURA), UC wished to explore development potentials fo...... to waterflow, from market to stream, from hedge to school garden and from trees to icons. 56 students first developed a list of key strategic proposals from the citizens groups vision papers, followed by specific design answers....

  2. Future urban transport

    DEFF Research Database (Denmark)

    Hansen, Carsten Jahn; Jacobsen, Lars; Möller, Michael

    2000-01-01

    The urban environment is usually associated with a variety of activities, which involve matching the demand for goods, commerce, services, rules and laws, culture and intellectual exchange. Proximity and congregation are essential factors when it comes to the economic efficiency of urban society....... However, the attractiveness of urban environments has caused cites to expand without control in many areas, causing congestion, and environmental and social problems. This session deals with the complexity of urban settings, including the impact of large infrastructure projects relating to safety, noise...

  3. Designing Urban Bikescapes

    DEFF Research Database (Denmark)

    Marling, Gitte

    2014-01-01

    This article presents analyses of the ‘Nørrebro Bike Route’ as an ‘urban bikescape’ consisting of a mixture of lanes and coupled urban places and small parks. It is a place to sit, to play and to relax, but at the same time it also a place for mobility. It is a social-technical assemblage (Urry 2...... (scale, rhythm, content) & aesthetics developed? (Thies- Evensen 1992, Venturi 1972, Rasmussen 2003, Thrift 2004, Merleau-Ponty 2009, Pallismaa 2005, Pink 2009)? Finally the article addresses the travelling ideas of ‘new urban bikescapes’ and Nordic urban space design....

  4. Arts of urban exploration

    DEFF Research Database (Denmark)

    Pinder, David

    2005-01-01

    to the city’ and ‘writing the city’. Through addressing recent cases of psychogeographical experimentation in terms of these themes, the paper raises broad questions about artistic practices and urban exploration to introduce this theme issue on ‘Arts of urban exploration’ and to lead into the specific......This paper addresses ways in which artists and cultural practitioners have recently been using forms of urban exploration as a means of engaging with, and intervening in, cities. It takes its cues from recent events on the streets of New York that involved exploring urban spaces through artistic...

  5. Monitoring urban growth

    DEFF Research Database (Denmark)

    Møller-Jensen, Lasse; Kofie, Richard; Yankson, Paul

    2007-01-01

    The extent of the urbanized areas of Accra is assessed from Landsat-TM satellite images for the year 2002 and compared to similar information for the years 1985 and 1991. A texture-based classification method is applied. The results show that the urbanization of the fringe areas of Accra is occur......The extent of the urbanized areas of Accra is assessed from Landsat-TM satellite images for the year 2002 and compared to similar information for the years 1985 and 1991. A texture-based classification method is applied. The results show that the urbanization of the fringe areas of Accra...

  6. Reuse of wastewater in urban farming and urban planning ...

    African Journals Online (AJOL)

    ISHIOMA

    status of wastewater reuse in urban farming in Katsina, an important urban area in the semi arid ... officially registered with the Katsina Urban Planning Authority. ..... crop production in the water-short Guanajuato river basin. Mexico. Res. Rep.

  7. Controlling factors of harmful microalgae distribution in water column, biofilm and sediment in shellfish production area (South of Sfax, Gulf of Gabes) from southern Tunisia

    Science.gov (United States)

    Loukil-Baklouti, Amira; Feki-Sahnoun, Wafa; Hamza, Asma; Abdennadher, Moufida; Mahfoudhi, Mabrouka; Bouain, Abderrahmen; Jarboui, Othman

    2018-01-01

    The aim of this study was to investigate the spatio-temporal distribution of harmful microalgae coupled with environmental factors in the most important area for natural stocks of the grooved carpet shell Ruditapes decussatus in southern Tunisia. Sampling was performed monthly from May 2010 to April 2011 in five stations through the Tunisian National Monitoring Stations Network of Phytoplankton and Phycotoxins along the southern coasts of Sfax (Gulf of Gabes). The presence of harmful microalgae species was explored in three compartments: water column, biofilm and sediment. Our results revealed fourteen species were identified belonging to dinoflagellates and diatoms with higher densities during the summer period. The co-inertia plot analysis exhibited that the seasonal fluctuations of these species were controlled by the temperature as well as the nutrients (particularly nitrogenous). Ternary diagrams showed that biofilm was the most colonized compartment by toxic benthic dinoflagellates species, namely Amphidinium carterae, Prorocentrum rathymum, Prorocentrum concavum, Prorocentrum lima, Ostreopsis cf. ovata and Coolia monotis. In addition, these species were recorded simultaneously in the water column and the sediment, a fact that could be explained by the resuspension of these benthic dinoflagellates from the biofilm by hydrodynamics. The data suggest that harmful microalgae could be the source of toxins in the studied stations, which provide support to the implication of these results on the future sampling strategy of harmful microalgae in shellfish collecting areas in Tunisia.

  8. Detection of adenoviruses in shellfish by means of conventional-PCR, nested-PCR, and integrated cell culture PCR (ICC/PCR).

    Science.gov (United States)

    Rigotto, C; Sincero, T C M; Simões, C M O; Barardi, C R M

    2005-01-01

    We tested three PCR based methodologies to detect adenoviruses associated with cultivated oysters. Conventional-PCR, nested-PCR, and integrated cell culture-PCR (ICC/PCR) were first optimized using oysters seeded with know amounts of Adenovirus serotype 5 (Ad5). The maximum sensitivity for Ad5 detection was determined for each method, and then used to detect natural adenovirus contamination in oysters from three aquiculture farms in Florianopolis, Santa Catarina State, Brazil, over a period of 6 months. The results showed that the nested-PCR was more sensitive (limit of detection: 1.2 PFU/g of tissue) than conventional-PCR and ICC-PCR (limit of detection for both: 1.2 x 10(2)PFU/g of tissue) for detection of Ad5 in oyster extracts. Nested-PCR was able to detect 90% of Ad5 contamination in harvested oyster samples, while conventional-PCR was unable to detect Ad5 in any of the samples. The present work suggests that detection of human adenoviruses can be used as a tool to monitor the presence of human viruses in marine environments where shellfish grow, and that nested-PCR is the method of choice.

  9. First evidence of "paralytic shellfish toxins" and cylindrospermopsin in a Mexican freshwater system, Lago Catemaco, and apparent bioaccumulation of the toxins in "tegogolo" snails (Pomacea patula catemacensis).

    Science.gov (United States)

    Berry, John P; Lind, Owen

    2010-05-01

    Exposure to cyanobacterial toxins in freshwater systems, including both direct (e.g., drinking water) and indirect (e.g., bioaccumulation in food webs) routes, is emerging as a potentially significant threat to human health. We investigated cyanobacterial toxins, specifically cylindrospermopsin (CYN), the microcystins (MCYST) and the "paralytic shellfish toxins" (PST), in Lago Catemaco (Veracruz, Mexico). Lago Catemaco is a tropical lake dominated by Cylindrospermopsis, specifically identified as Cylindrospermopsis catemaco and Cylindrospermopsis philippinensis, and characterized by an abundant, endemic species of snail (Pomacea patula catemacensis), known as "tegogolos," that is both consumed locally and commercially important. Samples of water, including dissolved and particulate fractions, as well as extracts of tegogolos, were screened using highly specific and sensitive ELISA. ELISA identified CYN and PST at low concentrations in only one sample of seston; however, both toxins were detected at appreciable quantities in tegogolos. Calculated bioaccumulation factors (BAF) support bioaccumulation of both toxins in tegogolos. The presence of CYN in the phytoplankton was further confirmed by HPLC-UV and LC-MS, following concentration and extraction of algal cells, but the toxin could not be confirmed by these methods in tegogolos. These data represent the first published evidence for CYN and the PST in Lago Catemaco and, indeed, for any freshwater system in Mexico. Identification of the apparent bioaccumulation of these toxins in tegogolos may suggest the need to further our understanding of the transfer of cyanobacterial toxins in freshwater food webs as it relates to human health. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Paralytic shellfish toxins in the Atlantic horse mackerel (Trachurus trachurus over a bloom of Gymnodinium catenatum: the prevalence of decarbamoylsaxitoxin in the marine food web

    Directory of Open Access Journals (Sweden)

    Sandra Lage

    2013-03-01

    Full Text Available This study reports the accumulation of paralytic shellfish toxins (PSTs in Atlantic horse mackerel (Trachurus trachurus over a bloom of the toxigenic dinoflagellate Gymnodinium catenatum. High levels of toxins, up to 4800 μg STXeq kg–1, were registered at the peak of the bloom (5.0 103 cells l–1. The suite of individual PSTs was examined. Decarbamoylsaxitoxin (dcSTX and B1 constituted nearly 90% of toxins (on a molar basis determined in mackerel. This profile of toxins markedly differs from the known profile of toxins produced by G. catenatum strains isolated from the Portuguese coast, which is dominated by N-sulfocarbamoyl toxins, in particular the C1+2 toxins. The prevalence of the potent dcSTX in the pelagic environment and its transfer through the marine food web is highlighted in this study. Atlantic horse mackerel is identified as a high potential vector of PSTs along the Portuguese coast. This fish species has a central position in the marine food web, being an important predator of zooplankton and at the same time an important diet item of top predators. This study reveals bioaccumulation values that are important for evaluating potential impacts of blooms of PST-producing dinoflagellates on marine ecosystems or their components, such as fish.

  11. Accumulation and elimination profiles of paralytic shellfish poison in the short-necked clam Tapes japonica fed with the toxic dinoflagellate Gymnodinium catenatum.

    Science.gov (United States)

    Samsur, Mohamad; Takatani, Tomohiro; Yamaguchi, Yasunaga; Sagara, Takefumi; Noguchi, Tamao; Arakawa, Osamu

    2007-02-01

    The paralytic shellfish poison (PSP)-producing dinoflagellate Gymnodinium catenatum (Gc) was fed to the short-necked clam Tapes japonica, and the accumulation, transformation and elimination profiles of PSP were investigated by means of high-performance liquid chromatography with postcolumn fluorescence derivatization (HPLC-FLD). The short-necked clams ingested most of the Gc cells (4 x 10(6) cells) supplied as a bolus at the beginning of the experiment, and accumulated a maximal amount of toxin (181 nmol/10 clams) after 12 hr. The rate of toxin accumulation at that time was 16%, which rapidly decreased thereafter. During the rearing period, a variation in toxin composition, derived presumably from the transformation of toxin analogues in the clams, was observed, including a reversal of the ratio of C2 to C1, and the appearance of carbamate (gonyautoxin (GTX) 2, 3) and decarbamoyl (dc) derivatives (decarbamoylsaxitoxin (dcSTX) and dcGTX2, 3), which were undetectable in Gc cells. The total amount of toxin contained in clams and residue (remaining Gc cells and/or excrement in the rearing tank) gradually declined, and only about 1% of the supplied toxin was detected at the end of the experiment.

  12. The identification of critical groups and its application to fish and shellfish consumers in the coastal area of the North-East Irish Sea

    International Nuclear Information System (INIS)

    Hunt, G.J.; Hewett, C.J.; Shepherd, J.G.

    1982-01-01

    Control of radioactive waste disposal to the environment, based on the recommendations of the International Commission on Radiological Protection (ICRP), necessitates an identification of the critical group of members of the public exposed from a given practice. Criteria for identification of critical groups based mainly on ICRP recommendations are discussed. Methods existing up to 1974 are briefly reviewed in the light of these criteria. Two more recent methods are described and compared on the basis of previous data; these methods, which are complementary, are based on homogeneity considerations and satisfy the criteria generally rather better than do the earlier methods. The application of the newer techniques to recent surveys of fish and shellfish consumption in the coastal area of the North-East Irish Sea is described, in relation to discharges from the Windscale reprocessing plant. The results of this survey are presented, and estimates are given of the effective dose equivalent to members of these critical groups in recent years, to show the effect of liquid discharges from Windscale in terms of public radiation exposure. (author)

  13. Detection, occurrence and monthly variations of typical lipophilic marine toxins associated with diarrhetic shellfish poisoning in the coastal seawater of Qingdao City, China.

    Science.gov (United States)

    Li, Xin; Li, Zhaoyong; Chen, Junhui; Shi, Qian; Zhang, Rutan; Wang, Shuai; Wang, Xiaoru

    2014-09-01

    In recent years, related research has mainly examined lipophilic marine toxins (LMTs) in contaminated bivalves or toxic algae, whereas the levels of LMTs in seawater remain largely unexplored. Okadaic acid (OA), yessotoxin (YTX), and pectenotoxin-2 (PTX2) are three typical LMTs produced by certain marine algae that are closely linked to diarrhetic shellfish poisoning. In this study, a new method of solid phase extraction combined with liquid chromatography - electrospray ionization ion trap tandem mass spectrometry was developed to determine the presence of OA, YTX, and PTX2 in seawater simultaneously. Satisfactory sensitivity, repeatability (RSDseawater. OA and PTX2 were detected in all the seawater samples collected from eight locations along the coastline of Qingdao City, China on October 23, 2012, with concentration ranges of OA 4.24-9.64ngL(-1) and PTX2 0.42-0.74ngL(-1). Monthly concentrations of OA and PTX2 in the seawater of four locations were determined over the course of a year, with concentration ranges of OA 1.41-89.52ngL(-1) and PTX2 below detectable limit to 1.70ngL(-1). The peak values of OA and PTX2 in coastal seawater were observed in August and July, respectively. Our results suggest that follow-up research on the fate modeling and risk assessment of LMTs in coastal seawater should be implemented. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  15. Urbanization, urban climate and influence of vegetation

    DEFF Research Database (Denmark)

    Feyisa, Gudina Legese

    and consequent problems. Through these papers, the project contributes to: 1) the science of remote sensing and Geographic Information System (GIS) by introducing methods that improve LULC classification accuracies, and an improved method of spatial thermal climate analyses, 2) better understanding of urban......, contributes to the research gaps by considering examples from two cities in Ethiopia, namely Addis Ababa and Adama. The major sources of data used in this study were remotely sensed multi-temporal digital imagery from Landsat TM and ETM+ sensors, ground surveying of LULC, measurements of air temperature...... and humidity, and questionnaire surveying. Remote sensing and GIS techniques were applied to analyze urbanization-induced dynamics of LULC and associated urban warming in five-year intervals between 1985 and 2010. LULC dynamics were analyzed applying post-classification change analysis using the Landsat...

  16. Revisiting Urban Dynamics through Social Urban Data

    Directory of Open Access Journals (Sweden)

    Achilleas Psyllidis

    2016-11-01

     The contribution of this doctoral thesis is the design and development of a framework of novel methods and tools that enables the fusion of heterogeneous multidimensional data for cities. The framework could foster planners, researchers, and policy makers to capitalize on the new possibilities given by emerging social urban data. Having a deep understanding of the spatiotemporal dynamics of cities and, especially of the activity and movement behavior of people, is expected to play a crucial role in addressing the challenges of rapid urbanization. Overall, the framework proposed by this research has potential to open avenues of quantitative explorations of urban dynamics, contributing to the development of a new science of cities.

  17. 2009 urban mobility report.

    Science.gov (United States)

    2009-07-01

    Congestion is a problem in Americas 439 urban areas, and it has gotten worse in regions of all : sizes. In 2007, congestion caused urban Americans to travel 4.2 billion hours more and to : purchase an extra 2.8 billion gallons of fuel for a conges...

  18. DIY Urban Design

    DEFF Research Database (Denmark)

    Fabian, Louise; Samson, Kristine

    2014-01-01

    of new experimentations with participatory process in urban design and the limits of staged participation. Through case-studies of the relocation of beer drinkers in Enghave Square in Copenhagen, the participatory and cultural urban planning initiatives in Køge municipality and examples of anonymous...

  19. Urbanizing rural waters

    NARCIS (Netherlands)

    Hommes, Lena; Boelens, Rutgerd

    2017-01-01

    This article studies how urbanization processes and associated rural-urban water transfers in the Lima region (Peru) create water control hierarchies that align the municipal drinking water company, hydropower plants and rural communities on unequal positions. By scrutinizing the history of water

  20. Urban Agri_polis

    DEFF Research Database (Denmark)

    Reynisdottir, Eva Margret; Hedegaard, Rikke; Harder, Henrik

    2009-01-01

    set i lidt bredere perspektiv, fx via "landbrugsproduktion" i eksisterende byområder, implementeres i en større skala - i byer, bydele og bynære landskaber. I 2025 forventes det, at 75 % af verdens befolkning vil være bosat i urbane områder. Visionen om "Urban Agriculture", eller fødevareproduktion i...

  1. The Urban Agriculture Circle

    NARCIS (Netherlands)

    Jansma, J.E.; Chambers, Joe; Sabas, Eva; Veen, E.J.

    2015-01-01

    The lack of inclusion of urban agriculture in city planning directly affects the success of initiatives in this sector, which subsequently could impede fu-ture innovations. The poor representation of urban agriculture in planning can be attributed to a lack of understanding about its

  2. Theme: Urban Agriculture.

    Science.gov (United States)

    Ellibee, Margaret; And Others

    1990-01-01

    On the theme of secondary agricultural education in urban areas, this issue includes articles on opportunities, future directions, and implications for the profession; creative supervised experiences for horticulture students; floral marketing, multicultural education; and cultural diversity in urban agricultural education. (JOW)

  3. Protected urban planet

    NARCIS (Netherlands)

    Pereira Roders, A.R.; Veldpaus, L.; Verbruggen, R.C.

    2012-01-01

    PUP, abbreviation to Protected Urban Planet, is the first tool developed for visualizing, mapping and contributing to information exchange on the evolution of protected urban areas worldwide. Besides locating them, it also provides communities with means to disseminate and raise awareness for their

  4. Urban Environmental Problems

    International Nuclear Information System (INIS)

    Situma, F.D.P.

    1999-01-01

    The rapid urbanization and resultant heavy concentration of population in urban centres have led to many urban areas failing to provide the necessary infrastructure and amenities as the demands placed on them have overwhelmed their financial and institutional capacities. In many urban areas, the capacity for resource mobilization and delivery of social services has either broken down completely or tethers on breaking point. Although in 1986 the GoK launched a new strategy for the balanced development of rural and urban areas aimed at avoiding excessive concentration of population in urban areas, the fruits of this strategy are yet to be realized. As a result, developments in urban areas have been unsustainable and environmentally unsound. The general quality of the environment has deteriorated so much so that urgent policy intervention is required. Appropriate environmental management measures and practices are needed to address the current trend of spiralling environmental problems in the context of the existing legal and institutional frameworks and makes some proposals for reform to address these problems in order to make urban areas environmentally

  5. Urbanization, Design & Liveability

    DEFF Research Database (Denmark)

    Reeh, Henrik; Gehl, Jan

    2014-01-01

    In this video documentary, produced for the Danish Ministry of Education and the ESOF2014 conference in Copenhagen by Alpha Film, Associate Professor and chairman of Urban Culture Lab, Henrik Reeh, explores urbanization, design, and liveability together with internationally renowned Danish...

  6. Sustainable urban regime adjustments

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  7. Modelling Urban Experiences

    DEFF Research Database (Denmark)

    Jantzen, Christian; Vetner, Mikael

    2008-01-01

    How can urban designers develop an emotionally satisfying environment not only for today's users but also for coming generations? Which devices can they use to elicit interesting and relevant urban experiences? This paper attempts to answer these questions by analyzing the design of Zuidas, a new...

  8. Mid-size urbanism

    NARCIS (Netherlands)

    Zwart, de B.A.M.

    2013-01-01

    To speak of the project for the mid-size city is to speculate about the possibility of mid-size urbanity as a design category. An urbanism not necessarily defined by the scale of the intervention or the size of the city undergoing transformation, but by the framing of the issues at hand and the

  9. Urbanization and human rights

    NARCIS (Netherlands)

    Mihr, A.

    Urban governance on the basis of human rights can help to set up problem solving mechanisms to guarantee social peace, economic growth and political participation.If states both integrate more in international or regional human rights regime and give more autonomy to urban governments and local

  10. Grooming Great Urban Teachers

    Science.gov (United States)

    Foster, Michele; Lewis, Jeffrey; Onafowora, Laura

    2005-01-01

    Master teachers working in real urban classrooms have shared their exemplary teaching practices in an After-School Pedagogical Laboratory (L-TAPL), a program for elementary students that aims to improve the achievement of urban students and the competence of their teachers. The L-TAPL enrichment program curriculum includes language arts, math,…

  11. Guidelines for Urban Labs

    DEFF Research Database (Denmark)

    Scholl, Christian; Agger Eriksen, Mette; Baerten, Nik

    2017-01-01

    urban lab initiatives from five different European cities: Antwerp (B), Graz and Leoben (A), Maastricht (NL) and Malmö (S). We do not pretend that these guidelines touch upon all possible challenges an urban lab may be confronted with, but we have incorporated all those we encountered in our...

  12. Urban Landscape Perspectives

    Directory of Open Access Journals (Sweden)

    Frederick Steiner

    2014-03-01

    Full Text Available Cities present significant opportunities for new landscape perspectives that can help inform conservation and development decisions. Early in the twenty-first century, the majority of the planet’s population became urban as more people lived in city-regions for the first time in our history. As the global population increases, so does this urbanization. The environmental challenges of population and urban growth are profound. Landscapes represent a synthesis of natural and cultural processes. Cities are certainly cultural phenomena. Historically, cities provided refuge from nature. The expanding field of urban ecology, coupled with landscape ecology, can enhance how the dual natural and cultural dimensions of landscapes in cities are understood. Furthermore, concepts such as ecosystem services and green infrastructure are proving useful for urban landscape planning and design. Examples from Dayton, Ohio; Brooklyn, New York; and Austin, Texas are presented.

  13. Urban lymphatic filariasis

    DEFF Research Database (Denmark)

    Simonsen, Paul Erik; Mwakitalu, Mbutolwe E.

    2013-01-01

    parasite species causing LF in humans, only Wuchereria bancrofti has been documented to have a significant potential for urban transmission. This is primarily because one of its vectors, Culex quinquefasciatus, thrives and proliferates excessively in crowded city areas with poor sanitary, sewerage...... impact. However, with rapid and unplanned growth of cities in the developing world, there is a need also to consider LF transmission and control in urban settings. Here, we review currently available knowledge on urban LF and the environmental and socio-economic basis for its occurrence. Among the three...... and drainage facilities. For this reason, urban LF also often shows a marked focality in distribution, with most cases clustered in areas inhabited by the less privileged city populations. More knowledge on urban LF is needed, in particular on its socio-economic and human behavioural context, on the potential...

  14. A blueprint for strategic urban research: the urban piazza.

    Science.gov (United States)

    Kourtit, Karima; Nijkamp, Peter; Franklin, Rachel S; Rodríguez-Pose, Andrés

    2014-01-01

    Urban research in many countries has failed to keep up with the pace of rapidly and constantly evolving urban change. The growth of cities, the increasing complexity of their functions and the complex intra- and inter-urban linkages in this 'urban century' demand new approaches to urban analysis, which, from a systemic perspective, supersede the existing fragmentation in urban studies. In this paper we propose the concept of the urban piazza as a framework in order to address some of the inefficiencies associated with current urban analysis. By combining wealth-creating potential with smart urban mobility, ecological resilience and social buzz in this integrated and systemic framework, the aim is to set the basis for a ' New Urban World ' research blueprint, which lays the foundation for a broader and more integrated research programme for strategic urban issues.

  15. Spatial Linkage and Urban Expansion: AN Urban Agglomeration View

    Science.gov (United States)

    Jiao, L. M.; Tang, X.; Liu, X. P.

    2017-09-01

    Urban expansion displays different characteristics in each period. From the perspective of the urban agglomeration, studying the spatial and temporal characteristics of urban expansion plays an important role in understanding the complex relationship between urban expansion and network structure of urban agglomeration. We analyze urban expansion in the Yangtze River Delta Urban Agglomeration (YRD) through accessibility to and spatial interaction intensity from core cities as well as accessibility of road network. Results show that: (1) Correlation between urban expansion intensity and spatial indicators such as location and space syntax variables is remarkable and positive, while it decreases after rapid expansion. (2) Urban expansion velocity displays a positive correlation with spatial indicators mentioned above in the first (1980-1990) and second (1990-2000) period. However, it exhibits a negative relationship in the third period (2000-2010), i.e., cities located in the periphery of urban agglomeration developing more quickly. Consequently, the hypothesis of convergence of urban expansion in rapid expansion stage is put forward. (3) Results of Zipf's law and Gibrat's law show urban expansion in YRD displays a convergent trend in rapid expansion stage, small and medium-sized cities growing faster. This study shows that spatial linkage plays an important but evolving role in urban expansion within the urban agglomeration. In addition, it serves as a reference to the planning of Yangtze River Delta Urban Agglomeration and regulation of urban expansion of other urban agglomerations.

  16. Urban Green Infrastructure as a tool for urban heat mitigation

    NARCIS (Netherlands)

    Saaroni, H.; Amorim, J.H.; Hiemstra, J.A.; Pearlmutter, D.

    2018-01-01

    The combined trends of urban heat island intensification and global warming are focusing attention on greening of cities as a tool for urban heat mitigation. Our study examines the range of research approaches and findings regarding the role of urban green infrastructure (UGI) in mitigating urban

  17. Urban agriculture and urban poverty alleviation: South African debates

    OpenAIRE

    Rogerson, Christian M.

    1998-01-01

    Growing international attention has focussed on the potential role of urban agriculture in poverty alleviation. The aim in this paper is to analyse the existing challenge of urban poverty in South Africa and examine the potential role of urban agriculture as a component of a pro-poor urban development strategy.

  18. Metal concentrations in urban riparian sediments along an urbanization gradient

    Science.gov (United States)

    Daniel J. Bain; Ian D. Yesilonis; Richard V. Pouyat

    2012-01-01

    Urbanization impacts fluvial systems via a combination of changes in sediment chemistry and basin hydrology. While chemical changes in urban soils have been well characterized, similar surveys of riparian sediments in urbanized areas are rare. Metal concentrations were measured in sediments collected from riparian areas across the urbanization gradient in Baltimore, MD...

  19. E – urban systems

    Directory of Open Access Journals (Sweden)

    Franc J. Zakrajšek

    2000-01-01

    Full Text Available Information and tele-communication technology are increasingly affecting life and employment. According to predictions, more than 80% of all business operations will be carried out electronically through so called e-business. Recently even in Slovenia discussions have begun on “e-government”. Despite desired or undesired control, virtual networks are changing urban systems into e-urban systems. The extent of benefits to the public also depend on planners. The article presents concepts with the signature “e” to describe urban systems, day-to-day life, real-estate and simulation.

  20. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel; Nielsen, Tom; Daugaard, Morten

    2010-01-01

    The article presents an attempt to develop alternatives to the dominant planning and design principles used in building and rebuilding the contemporary urban landscape. The basic idea is that the ‘forces of modernisation’ driving current development might result in a broader and more interesting...... for contemporary urban landscape design practice....... to the task of constructing and improving things. With this goal, a set of objectives based in important insights from recent urban theory are formulated constituting the normative spine of the analysis of a number of found situations as basis for formulating eight generic concepts of qualification...

  1. Picturing Urban Green Attachments

    DEFF Research Database (Denmark)

    Blok, Anders; Meilvang, Marie Leth

    2015-01-01

    In this article, we explore the cultural-political tensions and ambiguities of urban ecology, by way of following how activists move and translate between ‘familiar’ and ‘public’ engagements in the green city. Empirically, we locate our exploration in and around Nordhavnen (The North Harbor......), a large-scale sustainable urban development project in Copenhagen. Invoking Laurent Thévenot’s pragmatic sociology of ‘regimes of engagement’, we sketch a culturally sensitive approach to urban ecological activism, highlighting the critical moral capacities involved in building new forms of ‘commonality...

  2. Urban design for mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2017-01-01

    . In this paper, we shall explore the potential for a better understanding of contemporary urban challenges through the cross-disciplinary approach of ‘Mobilities design’. The paper investigates how this notion is based on an understanding of materialities and social action that is framed under the heading...... of ‘material pragmatism’. The paper critically discusses transport versus mobilities and uses the combination of urban design and mobilities not just to argue for a pragmatic approach to urban transformation, but also to illustrate how such a different frame of understanding is better suitable for the ‘kind...

  3. Lunar architecture and urbanism

    Science.gov (United States)

    Sherwood, Brent

    1992-01-01

    Human civilization and architecture have defined each other for over 5000 years on Earth. Even in the novel environment of space, persistent issues of human urbanism will eclipse, within a historically short time, the technical challenges of space settlement that dominate our current view. By adding modern topics in space engineering, planetology, life support, human factors, material invention, and conservation to their already renaissance array of expertise, urban designers can responsibly apply ancient, proven standards to the exciting new opportunities afforded by space. Inescapable facts about the Moon set real boundaries within which tenable lunar urbanism and its component architecture must eventually develop.

  4. Tetrodotoxin and paralytic shellfish poisons in gastropod species from Vietnam analyzed by high-performance liquid chromatography and liquid chromatography–tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Hsiao-Chin Jen

    2014-06-01

    Full Text Available Among marine toxins, tetrodotoxin (TTX and paralytic shellfish poisons (PSPs are known as notorious neurotoxins that induce serious food poisoning incidents in the Southeast Asia region. The aim of this study was to investigate whether TTX and PSP toxins are important issues of seafood safety. Paralytic toxicity was observed in mice exposed to 34 specimens from five species of gastropods using a PSP bioassay. Five species of gastropods, Natica vitellus, Natica tumidus, Oliva hirasei, Oliva lignaria, and Oliva annulata, were collected from the coastal seawaters in Nha Trang City, Vietnam, between August 2007 and October 2007. The average lethal potency of gastropod specimens was 90 ± 40 (mean ± standard deviation mouse units (MU for N. vitellus, 64 ± 19 MU for N. tumidus, 42 ± 28 MU for O. hirasei, 51 ± 17 MU for O. lignaria, and 39 ± 18 MU for O. annulata. All toxic extracts from the sample species were clarified using a C18 Sep-Pak solid-phase extraction column and a microcentrifuge filter prior to analysis. High-performance liquid chromatography coupled with fluorescence detection indicated that the toxins of the olive shell (O. hirasei, O. lignaria, and O. annulata were mainly composed of saxitoxin (STX (73–82%, gonyautoxin (GTX 2, 3 (12–22%, and minor levels of TTX (5–6%. The toxins of N. vitellus and N. tumidus were mainly composed of STX (76–81% and GTX 1, 4 (19–24%. Furthermore, liquid chromatography–tandem mass spectrometry analysis was used to verify the identity of the PSPs and TTX. Our evidence shows that these gastropods have novel toxin profiles.

  5. Determining the Advantages, Costs, and Trade-Offs of a Novel Sodium Channel Mutation in the Copepod Acartia hudsonica to Paralytic Shellfish Toxins (PST.

    Directory of Open Access Journals (Sweden)

    Michael Finiguerra

    Full Text Available The marine copepod Acartia hudsonica was shown to be adapted to dinoflagellate prey, Alexandrium fundyense, which produce paralytic shellfish toxins (PST. Adaptation to PSTs in other organisms is caused by a mutation in the sodium channel. Recently, a mutation in the sodium channel in A. hudsonica was found. In this study, we rigorously tested for advantages, costs, and trade-offs associated with the mutant isoform of A. hudsonica under toxic and non-toxic conditions. We combined fitness with wild-type: mutant isoform ratio measurements on the same individual copepod to test our hypotheses. All A. hudsonica copepods express both the wild-type and mutant sodium channel isoforms, but in different proportions; some individuals express predominantly mutant (PMI or wild-type isoforms (PWI, while most individuals express relatively equal amounts of each (EI. There was no consistent pattern of improved performance as a function of toxin dose for egg production rate (EPR, ingestion rate (I, and gross growth efficiency (GGE for individuals in the PMI group relative to individuals in the PWI expression group. Neither was there any evidence to indicate a fitness benefit to the mutant isoform at intermediate toxin doses. No clear advantage under toxic conditions was associated with the mutation. Using a mixed-diet approach, there was also no observed relationship between individual wild-type: mutant isoform ratios and among expression groups, on both toxic and non-toxic diets, for eggs produced over three days. Lastly, expression of the mutant isoform did not mitigate the negative effects of the toxin. That is, the reductions in EPR from a toxic to non-toxic diet for copepods were independent of expression groups. Overall, the results did not support our hypotheses; the mutant sodium channel isoform does not appear to be related to adaptation to PST in A. hudsonica. Other potential mechanisms responsible for the adaptation are discussed.

  6. Profiling of Extracellular Toxins Associated with Diarrhetic Shellfish Poison in Prorocentrum lima Culture Medium by High-Performance Liquid Chromatography Coupled with Mass Spectrometry

    Science.gov (United States)

    Pan, Lei; Chen, Junhui; Shen, Huihui; He, Xiuping; Li, Guangjiu; Song, Xincheng; Zhou, Deshan; Sun, Chengjun

    2017-01-01

    Extracellular toxins released by marine toxigenic algae into the marine environment have attracted increasing attention in recent years. In this study, profiling, characterization and quantification of extracellular toxin compounds associated with diarrhetic shellfish poison (DSP) in the culture medium of toxin-producing dinoflagellates were performed using high-performance liquid chromatography–high-resolution mass spectrometry/tandem mass spectrometry for the first time. Results showed that solid-phase extraction can effectively enrich and clean the DSP compounds in the culture medium of Prorocentrum lima (P. lima), and the proposed method achieved satisfactory recoveries (94.80%–100.58%) and repeatability (relative standard deviation ≤9.27%). Commercial software associated with the accurate mass information of known DSP toxins and their derivatives was used to screen and identify DSP compounds. Nine extracellular DSP compounds were identified, of which seven toxins (including OA-D7b, OA-D9b, OA-D10a/b, and so on) were found in the culture medium of P. lima for the first time. The results of quantitative analysis showed that the contents of extracellular DSP compounds in P. lima culture medium were relatively high, and the types and contents of intracellular and extracellular toxins apparently varied in the different growth stages of P. lima. The concentrations of extracellular okadaic acid and dinophysistoxin-1 were within 19.9–34.0 and 15.2–27.9 μg/L, respectively. The total concentration of the DSP compounds was within the range of 57.70–79.63 μg/L. The results showed that the proposed method is an effective tool for profiling the extracellular DSP compounds in the culture medium of marine toxigenic algae. PMID:28974018

  7. Presenting information on regulation values improves the public’s sense of safety: Perceived mercury risk in fish and shellfish and its effects on consumption intention

    Science.gov (United States)

    Suzuki, Mai; Yamaguchi, Tomiko

    2017-01-01

    Risk communication aims to promote health and understanding through information exchange; however, explanations regarding the basis of regulation values for the public are insufficient. Moreover, it is unclear how information presentation affects the public’s sense of safety and their consumption intentions. We first investigated the relationship between perception of mercury-risk in fish and shellfish and individual attributes and knowledge. We then examined how presenting information on regulation values and primary factors regarding perception affected sense of safety toward regulations and food-consumption intentions. An online survey was conducted with Japanese individuals (N = 1148). Respondents were randomly assigned to one of three groups based on the presentation level of regulation values. People who frequently consumed tuna had a high perception of dread risk of mercury. This suggests that the dread risk perception of mercury does not determine tuna-type consumption behavior; rather, individuals’ consumption behavior determines dread risk perception of mercury. Among those with high tuna-type consumption, those receiving information that a safety factor of 10 times had been considered showed a significantly greater sense of safety than did the group that was not presented with information on regulation values (odds ratio (95% confidence interval): 2.04 (1.18–3.53), p values showed a weak but significantly positive correlation with excessive intake of tuna-type fish (odds ratio: 2.95 (0.93–9.32), p values increases sense of safety; however, it may also lead to excessive intake. PMID:29267301

  8. Monitoring of Dinophysis species and diarrhetic shellfish toxins in Flødevigen Bay, Norway: inter-annual variability over a 25-year time-series.

    Science.gov (United States)

    Naustvoll, L-J; Gustad, E; Dahl, E

    2012-01-01

    The accumulation of phycotoxins in bivalve mussels associated with mussels feeding on toxic phytoplankton is a well-known phenomenon in Norway. Regular monitoring for 25 years has revealed that accumulation of Diarrhetic Shellfish poisoning (DSP) toxins in mussels is the main phycotoxin problem along the Norwegian coast. The aim of this study was to evaluate possible trends over time of Dinophysis spp. and DSP as well as possible correlation between abundance of Dinophysis spp. and toxin accumulation in mussels, as based on intensive and regular monitoring at the southern coast of Norway at Flødevigen Bay. The main source organism causing a risk of DSP in Norway is Dinophysis acuta. However, it cannot be excluded that other Dinophysis spp., e.g. D. acuminata and D. norvegica, may contribute to the total accumulation of toxins. The variability in the occurrence of these species is high at both short- and long-term; between days and between years. There are, however, some important overall patterns in the occurrence of the species during the last decades. Dinophysis acuminata and D. norvegica have mainly been abundant from March to December, whereas D. acuta has typically occurred in late summer and autumn (August-December). For all three species we have observed a narrowing of the peak season since 2002 at the same time as they have become less abundant. Coincident with these changes, the problem of the accumulation of DSP toxins in mussels along the southern coast of Norway has declined significantly, but it is still mainly restricted to the autumn. Why the cell concentration of Dinophysis spp. has declined after 2002 is not obvious, but this has occurred in a period with relatively high summer temperatures. The relatively simultaneous changes in physical, chemical and biological factors of the pelagic ecosystem along the southern coast of Norway indicate that complicated ecological interactions may be involved.

  9. Profiling of Extracellular Toxins Associated with Diarrhetic Shellfish Poison in Prorocentrum lima Culture Medium by High-Performance Liquid Chromatography Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Lei Pan

    2017-09-01

    Full Text Available Extracellular toxins released by marine toxigenic algae into the marine environment have attracted increasing attention in recent years. In this study, profiling, characterization and quantification of extracellular toxin compounds associated with diarrhetic shellfish poison (DSP in the culture medium of toxin-producing dinoflagellates were performed using high-performance liquid chromatography–high-resolution mass spectrometry/tandem mass spectrometry for the first time. Results showed that solid-phase extraction can effectively enrich and clean the DSP compounds in the culture medium of Prorocentrum lima (P. lima, and the proposed method achieved satisfactory recoveries (94.80%–100.58% and repeatability (relative standard deviation ≤9.27%. Commercial software associated with the accurate mass information of known DSP toxins and their derivatives was used to screen and identify DSP compounds. Nine extracellular DSP compounds were identified, of which seven toxins (including OA-D7b, OA-D9b, OA-D10a/b, and so on were found in the culture medium of P. lima for the first time. The results of quantitative analysis showed that the contents of extracellular DSP compounds in P. lima culture medium were relatively high, and the types and contents of intracellular and extracellular toxins apparently varied in the different growth stages of P. lima. The concentrations of extracellular okadaic acid and dinophysistoxin-1 were within 19.9–34.0 and 15.2–27.9 μg/L, respectively. The total concentration of the DSP compounds was within the range of 57.70–79.63 μg/L. The results showed that the proposed method is an effective tool for profiling the extracellular DSP compounds in the culture medium of marine toxigenic algae.

  10. Profiling of Extracellular Toxins Associated with Diarrhetic Shellfish Poison in Prorocentrum lima Culture Medium by High-Performance Liquid Chromatography Coupled with Mass Spectrometry.

    Science.gov (United States)

    Pan, Lei; Chen, Junhui; Shen, Huihui; He, Xiuping; Li, Guangjiu; Song, Xincheng; Zhou, Deshan; Sun, Chengjun

    2017-09-30

    Extracellular toxins released by marine toxigenic algae into the marine environment have attracted increasing attention in recent years. In this study, profiling, characterization and quantification of extracellular toxin compounds associated with diarrhetic shellfish poison (DSP) in the culture medium of toxin-producing dinoflagellates were performed using high-performance liquid chromatography-high-resolution mass spectrometry/tandem mass spectrometry for the first time. Results showed that solid-phase extraction can effectively enrich and clean the DSP compounds in the culture medium of Prorocentrum lima ( P. lima ), and the proposed method achieved satisfactory recoveries (94.80%-100.58%) and repeatability (relative standard deviation ≤9.27%). Commercial software associated with the accurate mass information of known DSP toxins and their derivatives was used to screen and identify DSP compounds. Nine extracellular DSP compounds were identified, of which seven toxins (including OA-D7b, OA-D9b, OA-D10a/b, and so on) were found in the culture medium of P. lima for the first time. The results of quantitative analysis showed that the contents of extracellular DSP compounds in P. lima culture medium were relatively high, and the types and contents of intracellular and extracellular toxins apparently varied in the different growth stages of P. lima . The concentrations of extracellular okadaic acid and dinophysistoxin-1 were within 19.9-34.0 and 15.2-27.9 μg/L, respectively. The total concentration of the DSP compounds was within the range of 57.70-79.63 μg/L. The results showed that the proposed method is an effective tool for profiling the extracellular DSP compounds in the culture medium of marine toxigenic algae.

  11. Exploring Urban Screens

    Directory of Open Access Journals (Sweden)

    Zlatan Krajina

    2009-12-01

    Full Text Available There is a tautological tendency in the widespread claims that urban space is 'me-diated'. Never before has the citizen, it is argued, been confronted with such an unprecedented array of signage. I depart from the rhetoric of 'biggest-ever-saturation' as not necessarily untrue, but as insufficient in exploring the diverse spatial operations of urban screens. I examine some contemporary cases of ani-mated architectural surfaces, informational panels, and advertising billboards, with reference to much longer standing cultural practices of spatial management in modern cities, such as illumination, to suggest that the contemporary display media do not mediate the city anew but re-invent urban space as a field of ubiqui-tous mediation. From that standpoint I suggest exploring urban screens as a both singular visual agents and indivisible items in plural structural assemblages, b complementary forces of public illumination, and c complex perceptual platforms in visual play of scale and distance.

  12. Mozambique - Urban Land Regularization

    Data.gov (United States)

    Millennium Challenge Corporation — This baseline survey was developed for the impact evaluation of activities related to 'improving land access in urban hotspot areas.' The site-specific interventions...

  13. Urban heat island 1

    DEFF Research Database (Denmark)

    Bühler, Oliver; Jensen, Marina Bergen; Petersen, Karen Sejr

    2010-01-01

    Urban Heat Island beskriver det forhold, at temperaturen i byområder er højere end temperaturen i tilgrænsede landområder. Årsagen hertil ligger i den urbane arealanvendelse, hvor en mindre andel af arealerne er dækket af vegetation, og en større andel består af forseglede arealer.......Urban Heat Island beskriver det forhold, at temperaturen i byområder er højere end temperaturen i tilgrænsede landområder. Årsagen hertil ligger i den urbane arealanvendelse, hvor en mindre andel af arealerne er dækket af vegetation, og en større andel består af forseglede arealer....

  14. Urban Sound Interfaces

    DEFF Research Database (Denmark)

    Breinbjerg, Morten

    2012-01-01

    This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live. In this pa......This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live....... In this paper, three sound works are discussed in relation to the iPod, which is considered as a more private way to explore urban environments, and as a way to control the individual perception of urban spaces....

  15. CONSIDERATIONS ON URBAN SOILS

    Directory of Open Access Journals (Sweden)

    Radu Lacatusu

    2005-10-01

    Full Text Available Urban soil is an material that has been manipulated, disturbed or transported by man’s activities in the urban environment and is used as a medium for plant growth and for constructions. The physical, chemical, and biological properties are generally less favorable as a rooting medium than soil found on the natural landscape. The main characteristics of urban soils are: great vertical and spatial variability; modified soil structure leading to compaction; presence of a surface crust; modified soil reaction, usually elevated; restricted aeration and water drainage; modified abundance of chemical elements, interrupted nutrient cycling and soil organism activity; presence of anthropic materials contaminants and pollutants; modified soil temperature regime. The urbic horizon is designated as U (always capital letter and for indication of processes are used different small letters. It is necessary elaboration a new classification of urban soils for our country.

  16. Health and urban living.

    Science.gov (United States)

    Dye, Christopher

    2008-02-08

    The majority of people now live in urban areas and will do so for the foreseeable future. As a force in the demographic and health transition, urbanization is associated with falling birth and death rates and with the shift in burden of illness from acute childhood infections to chronic, noncommunicable diseases of adults. Urban inhabitants enjoy better health on average than their rural counterparts, but the benefits are usually greater for the rich than for the poor, thus magnifying the differences between them. Subject to better evidence, I suggest that the main obstacles to improving urban health are not technical or even financial, but rather are related to governance and the organization of civil society.

  17. Master in Urban Quality

    DEFF Research Database (Denmark)

    2006-01-01

    Development and content of an international Master in Urban Quality development and management. The work has been done in a cooperation between Berlage institut, Holland; Chulalongkorn University, Thailand; Mahidol University, Thailand; University Kebangsaan Malaysia, Malaysia; og Aalborg...

  18. Our Urban Living Room

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus

    2016-01-01

    Our Urban Living Room is an exhibition and a book, created by Cobe. The theme is based on Cobe’s ten years of practice, grounded in social livability and urban democracy, and our aim to create buildings and spaces that invite Copenhageners to use and define them; as an extended living room, where...... the boundaries between private and public space become fluid. Based on specific Cobe projects, Our Urban Living Room tells stories about the architectural development of Copenhagen, while exploring the progression of the Danish Capital - from an industrial city into an urban living room, known as one...... of the world’s most livable places. Photography by Rasmus Hjortshøj....

  19. Urbanization and Inequality/Poverty

    Directory of Open Access Journals (Sweden)

    Brantley Liddle

    2017-11-01

    Full Text Available The level of world urbanization has crossed the 50% mark, and nearly all future population growth is projected to occur in cities. Cities are disproportionately wealthy, but are associated with poverty, too. Addressing the dual challenges of urbanization and poverty is key to achieving sustainable development. This paper performs cross-sectional regressions, based on Kuznets, as a starting point for understanding the relationship between urbanization and poverty/inequality indicators. Increases in gross domestic product per capita unambiguously lowered poverty and narrowed rural-urban gaps. By contrast, levels of urbanization were either unrelated to poverty/inequality indicators and measures of rural-urban gaps, or had a nonlinear effect where, initially, increases in urbanization likewise led to improvements in those areas, while at higher levels of urbanization, increases in urbanization exacerbated poverty and rural-urban gaps.

  20. Urbanism Faced with the New Urban Revolution

    DEFF Research Database (Denmark)

    Ascher, François

    2002-01-01

    Med den industrielle revolution fulgte den urbane revolution og urbanismen som bymæssig videns- og planlægningsdisciplin. Med de nye informations- og kommunikationsteknologier står vi i dag over for samfundsmæssige forandringer, som sætter en ny urban revolution på dagsordenen. Urbanismen er...... tilsvarende ved at blive afløst af en "meta-urbanisme", som adskiller sig fra den foregående med hensyn til målsætninger, kundskabsmæssige redskaber og handlingsinstrumenter. I artiklen redegøres for sammenhænge mellem disse teknologiske, samfundsmæssige, bymæssige og urbanistiske forandringer....

  1. The future is urban.

    Science.gov (United States)

    1992-05-01

    Urban centers are growing due to natural increase and the movement of people from rural areas. Urban areas are the traditional centers of trade, science, and culture, but growth over a threshold results in crime, congestion, and pollution. Sustainability is threatened in modern towns that are dependent on other sources for food, fuel, or water. Housing, water, food supplies, and sanitation, communication, and transportation services are threatened in rapidly growing cities. In 1990 45/100 people lived in towns or cities. Hyper-cities have grown in number to 20, of which 14 are in developing countries. 83% of world population increase is expected to occur in cities. In 48 countries with faster population growth cities had growth rates averaging about 6.1% per year, and the urban share of total population averaged 2.8%. In 49 countries with slower population growth, urban growth rates averaged only 3.6% per year, and the urban share of total population averaged about 1.8%. Squatter settlements are endemic to urban areas that are congested and without basic services, limited housing particularly for the poor, and few job opportunities. The number of street children in urban areas has risen. This child population is subjected to low wages, overwork, auto accidents, poor health, and lack of social services. Malnutrition is a more serious issue in urban areas. In the Philippines malnutrition is 3% nationally and 9% in Metro Manila. Rural land reform in the Philippines is no longer a viable solution. In Metro Manila squatters are expected to increase in number to 4 million people by the year 2000, which would be almost 50% of total population. The squatter areas are areas of neglect, decay, and poverty. Cities are viewed as development's "blind alleys."

  2. Urbanization and Structural Transformation

    OpenAIRE

    Michaels, Guy; Rauch, Ferdinand; Redding, Stephen J.

    2008-01-01

    This paper presents new evidence on urbanization using sub-county data for the United States from 1880-2000 and municipality data for Brazil from 1970-2000. We show that the two central stylized features of population growth for cities - Gibrat's Law and a stable population distribution - are strongly rejected when both rural and urban areas are considered. Population growth exhibits a U-shaped relationship with initial population density, and only becomes uncorrelated with initial population...

  3. Guidelines for Urban Labs

    DEFF Research Database (Denmark)

    Scholl, Christian; Agger Eriksen, Mette; Baerten, Nik

    2017-01-01

    These guidelines are intended for team members and managers of urban labs and, more generally, for civil servants and facilitators in cities working with experimental processes to tackle complex challenges. They aim to support the everyday practice of collaboratively experimenting and learning ho...... the result is inspiring and instructive for all those who want to wrap their minds around experimental co-creative approaches to urban governance and city development....

  4. Urbanization and Slum Formation

    Science.gov (United States)

    Phua, Kai Hong

    2007-01-01

    The formation of slums need not be inevitable with rapid urbanization. Such an argument appears to be contradicted by evidence of large slum populations in a large number of developing countries and particularly in rapidly urbanizing regions like Asia. The evidence discussed suggests that city authorities faced with rapid urban development lack the capacity to cope with the diverse demands for infrastructural provision to meet economic and social needs. Not only are strategic planning and intervention major issues in agenda to manage rapid urbanization, but city governments are not effectively linking the economic development trajectory to implications for urban growth and, hence, housing needs. In the following discussion, a case study is presented in support of the argument that city governments have to first recognize and then act to establish the link that is crucial between economic development, urban growth, and housing. This is the agendum that has been largely neglected by city and national governments that have been narrowly focused on economic growth with the consequent proliferation of slum formation as a housing solution. PMID:17387618

  5. Urban photovoltaic electricity policies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme takes a look at urban photovoltaic electricity policies. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy as a significant and sustainable renewable energy option. The objective of Task 10 is stated as being to enhance the opportunities for wide-scale, solution-oriented application of photovoltaics in the urban environment. The goal of the study presented was to evaluate a standardised basis for urban policies regarding photovoltaic integration in a set of cities in the countries participating in the IEA's Task 10, Urban Scale PV. The investigation was focused on three topics: the present state of the policies, the prospects for future policies fostering photovoltaic deployment and the prospects for future policies to cope with large-scale photovoltaic integration. The first section analyses the state of the policies; this analysis is then confirmed in section 2, which deals with present obstacles to PV deployment and solutions to overcome them. The third section investigates future prospects for PV deployment with the question of mastering large scale integration. The report concludes that cities could formulate urban solutions by developing integrated, specific provisions for PV deployment in their urban infrastructure planning.

  6. Towards sustainable urban communities

    International Nuclear Information System (INIS)

    Haapio, Appu

    2012-01-01

    Requirements for the assessment tools of buildings have increased, assessing of building components or separate buildings is not enough. Neighbourhoods, built environment, public transportations, and services, should be considered simultaneously. Number of population living in urban areas is high and increasing rapidly. Urbanisation is a major concern due to its detrimental effects on the environment. The aim of this study is to clarify the field of assessment tools for urban communities by analysing the current situation. The focus is on internationally well known assessment tools; BREEAM Communities, CASBEE for Urban Development and LEED for Neigborhood Development. The interest towards certification systems is increasing amongst the authorities, and especially amongst the global investors and property developers. Achieved certifications are expected to bring measureable publicity for the developers. The assessment of urban areas enables the comparison of municipalities and urban areas, and notably supports decision making processes. Authorities, city planners, and designers would benefit most from the use of the tools during the decision making process. - Highlights: ► The urban assessment tools have strong linkage to the region. ► The tools promote complementary building and retrofitting existing sites. ► Sharing knowledge and experiences is important in the development of the tools.

  7. The use of electron spin resonance spectroscopy for the detection of irradiated shellfish and spices; Elektronenspinresonanz-spektroskopische Untersuchungen zur Identifizierung bestrahlter Krustentiere und Gewuerze: Durchfuehrung eines Ringversuches an Nordseekrabben, Kaisergranat und Paprikapulver

    Energy Technology Data Exchange (ETDEWEB)

    Helle, N. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Linke, B. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Boegl, K.W. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Schreiber, G.A. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany)

    1994-12-31

    A multilateral study on common shrimps, Norway lobster and paprika powder. The use of ESR spectroscopy in shellfish and some types of spice for the detection of previous irradiation is possible even on a routine basis. The radicals producing the specific ESR signals observed could at least in part be identified (CO{sup 2} radicals in shellfish, cellulose radicals in paprica) and the overall rate of correct classifications was seen to be very high for this multicentre study. The multicentre study has further been able to prove that previous reservations about ESR as a method of detection are no longer justified. The authors hold that there is no reason in principle why ESR should not be on the list of officially recommended methods for the examination of shellfish and spices according to paragraph35 LMBG. Nevertheless, the two groups of food at issue here need to be investigated in more detail in a number of further research projects, some of which are mentioned in the following: - investigations on further species of shellfish so as to obtain a broad range of spectra for routine controls; - structural identification of radiation-specific radicals generated in addition to the CO{sup 2} radical; - investigations into the influences of origin, time of fishing and stage of development on the ESR spectra of fishes; - examinations of further spices; - elucidation of links between cellulose contents and radical concentration. (orig./vhe) [Deutsch] Die Identifizierung bestrahlter Krustentiere und einiger bestrahlter Gewuerze mit Hilfe der ESR-Spektroskopie ist auch in der Routine moeglich. Die fuer die beobachteten spezifischen ESR-Signale verantwortlichen Radikale konnten zumindest teilweise identifiziert werden (CO{sup 2-} - Radikal bei Krustentieren, Cellulose-Radikal bei Paprika) und im Ringversuch wurde eine sehr hohe Quote richtiger Identifizierungen erreicht. Der Ringversuch hat zudem bewiesen, dass die bisher zur ESR-Methode geaeusserten prinzipiellen Bedenken

  8. Paralytic shellfish toxin profile in strains of the dinoflagellate Gymnodium cataenatum and the scallop Argopecten ventricosus G.B. Sowerby II from Bahia Concepción, Gulf of California, Mexico

    OpenAIRE

    Band Schmidt, Christine Johanna; Bustillos Guzmán, José J.; Gárate Lizárraga, Ismael; Lechuga Deveze, Carlos; Reinhardt, K.; Luckas, Bernd

    2005-01-01

    Gymnodinium catenatum Graham is a paralytic shellfish poison (PSP) producer that was described for the first time from the Gulf of California in 1943. During the last decade, its distribution along the Mexican Pacific coastline has increased. In Bahía Concepción, a coastal lagoon on the western side of the Gulf of California, G. catenatum has been linked to significant PSP concentrations found in mollusks. In this study, we describe the saxitoxin profile of 16 strains of G. catenatum, and cat...

  9. Urban farming activity towards sustainable wellbeing of urban dwellers

    Science.gov (United States)

    Othman, N.; Mohamad, M.; Latip, R. A.; Ariffin, M. H.

    2018-02-01

    In Malaysia, urban farming is viewed as a catalyst towards achieving the well-being of urban dwellers and natural environment. Urban farming is a strategy for Malaysia’s food and economic security, and as one of the foci in the agriculture transformation whereby urban dwellers are encouraged to participate in this activity. Previous study proved that urban farming can help to address social problems of food security, urban poverty and high living cost, also provides leisure and recreation among urban dwellers. Thus, this study investigates the best urban farming practices suitable for urban setting, environment and culture of urban dwellers. Data collection was done via questionnaire survey to urban farmers of a selected community garden in Subang Jaya, Selangor. Meanwhile, on-site observations were carried out on gardening activities and the gardens’ physical attributes. The study sample encompasses of 131 urban farmers of 22 community gardens in Subang Jaya. It was found that most of the community gardens practiced crops planting on the ground or soil base planting and dwellers in the lower income group with monthly low household income constitutes the majority (83.2%) of the respondents. Social and health benefits are the highest motivating factors for urban farmers. This study provides unprecedented insights on urban farming practices and motivations in a Malaysian setting.

  10. Urban Spaces and Safety

    Directory of Open Access Journals (Sweden)

    Rosa Grazia De Paoli

    2012-11-01

    Full Text Available The concept of vulnerability understood in the traditional sense as a “single manufactured good” is insufficient when it comes to describing the real conditions of an urban system’s vulnerability within which an indefinite variable of factors interact with one another thereby determining the damage caused by an earthquake. These interacting factors constitute so-called “urban vulnerability” which town planners use in order to contribute to the field in the form of analysis definition and interventions in the mitigation of seismic risk on an urban scale. The research paper “Relational Spaces as Safe Places” positions itself firmly in the vein of town planning research which focuses on the mitigation of seismic risk, and which intends to blaze a new methodological trail that aims to identify safety traits in urban spaces. The research paper’s starting point is the assumption that empty urban spaces, given the indications provided by the principal organs for Civic Protection, have come to be seen as the spaces designed to accommodate the public in cases of emergency. This can generate new thought regarding town planning by reviewing early post-earthquake urban designs where the rules were laid out for earthquake-proof cities: a “chessboard” plan with wide streets, both straight and perpendicular, empty spaces like squares and markets positioned along the longitudinal streets, and buildings with regular layouts all at right-angles. These simple guidelines, which are often disregarded and distorted in modern towns, are extraordinarily relevant and oriented towards new definitions of the urban traits of quality and security.

  11. Urban air quality

    International Nuclear Information System (INIS)

    Fenger, J.

    1999-01-01

    Since 1950 the world population has more than doubled, and the global number of cars has increased by a factor of 10. In the same period the fraction of people living in urban areas has increased by a factor of 4. In year 2000 this will amount to nearly half of the world population. About 20 urban regions will each have populations above 10 million people. Seen over longer periods, pollution in major cities tends to increase during the built up phase, they pass through a maximum and are then again reduced, as abatement strategies are developed. In the industrialised western world urban air pollution is in some respects in the last stage with effectively reduced levels of sulphur dioxide and soot. In recent decades however, the increasing traffic has switched the attention to nitrogen oxides, organic compounds and small particles. In some cities photochemical air pollution is an important urban problem, but in the northern part of Europe it is a large-scale phenomenon, with ozone levels in urban streets being normally lower than in rural areas. Cities in Eastern Europe have been (and in many cases still are) heavily polluted. After the recent political upheaval, followed by a temporary recession and a subsequent introduction of new technologies, the situation appears to improve. However, the rising number of private cars is an emerging problem. In most developing countries the rapid urbanisation has so far resulted in uncontrolled growth and deteriorating environment. Air pollution levels are here still rising on many fronts. Apart from being sources of local air pollution, urban activities are significant contributors to transboundary pollution and to the rising global concentrations of greenhouse gasses. Attempts to solve urban problems by introducing cleaner, more energy-efficient technologies will generally have a beneficial impact on these large-scale problems. Attempts based on city planning with a spreading of the activities, on the other hand, may generate

  12. The urban environment

    International Nuclear Information System (INIS)

    Roed, J.

    1997-01-01

    Since the majority of the population of Nordic countries, and indeed most of Western Europe, reside in towns and cities, decontamination and reclamation of urban areas must figure prominently in nuclear accident contingency planning. If clean-up is to be both efficient and cost-effective a number of factors must be taken into account. They are: distribution of the deposited radionuclide(s) on the various urban surfaces (roofs, soil, walls, roads etc.); radiation levels on the various surfaces; attenuation of radiation through shielding by urban structures (e.g. walls); habits of the populace with respect to time spent indoors and outdoors and time spent on various floors within buildings typical of particular urban complexes; decontamination by natural processes, described as weathering (which includes rain, traffic, routine cleaning); diminution in radiation levels through radioactive decay; decontamination achievable by artificial means. Of all the radioactive materials which might be released in the event of a severe accident, 134 Cs and 137 Cs would present the greatest radiation hazard to the populace of a contaminated urban complex in both the medium and long-term. (EG)

  13. The prevalence and characteristics of food allergy in urban minority children.

    Science.gov (United States)

    Taylor-Black, Sarah; Wang, Julie

    2012-12-01

    Urban minority children are known to have high rates of asthma and allergic rhinitis, but little is known about food allergy in this population. To examine the prevalence and characteristics of food allergy in an urban pediatric population. A retrospective review of electronic medical records from children seen in the hospital-based general pediatric clinic at Mount Sinai Hospital serving East Harlem, NY, between July 1, 2008 and July 1, 2010 was performed. Charts for review were selected based on diagnosis codes for food allergy, anaphylaxis, or epinephrine autoinjector prescriptions. Of 9,184 children seen in this low-income, minority clinic, 3.4% (313) had a physician-documented food allergy. The most common food allergies were peanut (1.6%), shellfish (1.1%), and tree nuts (0.8%). Significantly more black children (4.7%) were affected than children of other races (2.7%, P food-allergic children, asthma (50%), atopic dermatitis (52%), and allergic rhinitis (49%) were common. Fewer than half had confirmatory testing or evaluation by an allergy specialist, and although most had epinephrine autoinjectors prescribed, most were not prescribed food allergy action plans. This is the largest study of food allergy prevalence in an urban minority pediatric population, and 3.4% had physician-documented food allergy. Significantly more blacks were affected than children of other races. Fewer than half of food-allergic children in this population had confirmatory testing or evaluation by an allergy specialist. Copyright © 2012 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Urban energy planning in Turku

    DEFF Research Database (Denmark)

    Fertner, Christian; Christensen, Emil Maj; Große, Juliane

    prevailing urban sprawl, characterising urban development since the 1950s. The city is densifying and promoting sustainable urban develop-ment, though at a regional scale with several growth centres. Its future development is envisioned in the “Structure model 2035”, focusing on more compact urban...... development along public transport corridors. From the case report three issues arise which might be of considerable interest in a broader context of the PLEEC project: 1. Working with energy efficient regional urban structure (e.g. regarding urban sprawl) in a low density country and on a voluntary...

  15. Urban Fields in the making

    DEFF Research Database (Denmark)

    Hovgesen, Henrik Harder; Nielsen, Thomas Alexander Sick

    cities and accentuates the concept of the ?urban field? suggested by John Friedmann (1978). The concept of ?urban field? suggest that mobility has been democratizised and increased to a level where several cities can be part of the same functionally integrated urban field. As a consequence...... the significance of the single urban centre and the city as an entity will change markedly. This paper aims to analyse the development towards urban travel- and commuter fields in Denmark. The question asked is to what degree urban fields are emerging? ? And what is the speed of this development....

  16. Food contaminant analysis at ultra-high mass resolution: application of hybrid linear ion trap - orbitrap mass spectrometry for the determination of the polyether toxins, azaspiracids, in shellfish.

    LENUS (Irish Health Repository)

    2010-10-30

    The biotoxins, azaspiracids (AZAs), from marine phytoplankton accumulate in shellfish and affect human health by causing severe gastrointestinal disturbance, diarrhea, nausea and vomiting. Specific and sensitive methods have been developed and validated for the determination of the most commonly occurring azaspiracid analogs. An LTQ Orbitrap mass spectrometer is a hybrid instrument that combines linear ion trap (LIT) mass spectrometry (MS) with high-resolution Fourier transform (FT) MS and this was exploited to perform simultaneous ultra-high-resolution full-scan MS analysis and collision-induced dissociation (CID) tandem mass spectrometry (MS\\/MS). Using the highest mass resolution setting (100,000 FWHM) in full-scan mode, the methodology was validated for the determination of six AZAs in mussel (Mytilus galloprovincialis) tissue extracts. Ultra-high mass resolution, together with a narrow mass tolerance window of ±2 mDa, dramatically improved detection sensitivity. In addition to employing chromatographic resolution to distinguish between the isomeric azaspiracid analogs, AZA1\\/AZA6 and AZA4\\/AZA5, higher energy collisionally induced dissociation (HCD) fragmentation on selected precursor ions were performed in parallel with full-scan FTMS. Using HCD MS\\/MS, most precursor and product ion masses were determined within 1 ppm of the theoretical m\\/z values throughout the mass spectral range and this enhanced the reliability of analyte identity.For the analysis of mussels (M. galloprovincialis), the method limit of quantitation (LOQ) was 0.010 µg\\/g using full-scan FTMS and this was comparable with the LOQ (0.007 µg\\/g) using CID MS\\/MS. The repeatability data were; intra-day RSD% (1.8-4.4%; n = 6) and inter-day RSD% (4.7-8.6%; n = 3). Application of these methods to the analysis of mussels (M. edulis) that were naturally contaminated with azaspiracids, using high-resolution full-scan Orbitrap MS and low-resolution CID MS\\/MS, produced

  17. Improved microwave-assisted wet digestion procedures for accurate Se determination in fish and shellfish by flow injection-hydride generation-atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Lavilla, I.; Gonzalez-Costas, J.M.; Bendicho, C.

    2007-01-01

    Accurate determination of Se in biological samples, especially fish and shellfish, by hydride generation techniques has generally proven troublesome owing to the presence of organoselenium that cannot readily converted into inorganic selenium under usual oxidising conditions. Further improvements in the oxidation procedures are needed so as to obtain accurate concentration values when this type of samples is analyzed. Microwave-assisted wet digestion (MAWD) procedures of seafood based on HNO 3 or the mixture HNO 3 /H 2 O 2 and further thermal reduction of the Se(VI) formed to Se(IV) were evaluated. These procedures were as follows: (I) without H 2 O 2 and without heating to dryness; (II) without H 2 O 2 and with heating to dryness; (III) with H 2 O 2 and without heating to dryness; (IV) with H 2 O 2 and with heating to dryness. In general, low recoveries of selenium are obtained for several marine species (e.g., crustaceans and cephalopods), which may be ascribed to the presence of Se forms mainly associated with nonpolar proteins and lipids. Post-digestion UV irradiation proved very efficient since not only complete organoselenium decomposition was achieved but also the final step required for prereduction of Se(VI) into Se(IV) (i.e. heating at 90 deg. C for 30 min in 6 M HCl) could be avoided. With the MAWD/UV procedure, the use of strong oxidising agents (persuphate, etc.) or acids (e.g. perchloric acid) which are typically applied prior to Se determination by hydride generation techniques is overcome, and as a result, sample pre-treatment is significantly simplified. The method was successfully validated against CRM DOLT-2 (dogfish liver), CRM DORM-2 (dogfish muscle) and CRM TORT-2 (lobster hepatopancreas). Automated ultrasonic slurry sampling with electrothermal atomic absorption spectrometry was also applied for comparison. Total Se contents in ten seafood samples were established. Se levels ranged from 0.7 to 2.9 μg g -1

  18. Complex profiles of hydrophobic paralytic shellfish poisoning compounds in Gymnodinium catenatum identified by liquid chromatography with fluorescence detection and mass spectrometry.

    Science.gov (United States)

    Vale, Paulo

    2008-06-27

    The presence of hydrophobic analogues of paralytic shellfish poisoning toxins (PSTs) was studied in a Portuguese strain of Gymnodinium catenatum by conventional pre-column oxidation HPLC after a prolonged acetonitrile gradient coupled with fluorescence detection. Prior separation of hydrophobic PSTs analogues from hydrophilic analogues was done by solid-phase extraction (SPE) partitioning on a C18 cartridge. Several unknown oxidation products, with emission spectra similar to known PSTs, appeared after periodate or hydrogen peroxide oxidation. The compounds producing these oxidation products could be grouped into three major sub-groups according to SPE partitioning. The first one eluting with 10 and 20% MeOH, produced the first set of oxidation products observed after the saxitoxin oxidation product. The second one eluting with 30-100% MeOH produced the second set of oxidation products. The third one eluted with acidified 90% MeOH produced the third and last set of oxidation products. Additionally, the oxidation products corresponding to decarbamoyl gonyautoxins and decarbamoyl saxitoxins were also abundant, resulting from ester cleavage of the benzoate side chain of these compounds during the oxidation. Analysis of these fractions by LC-MS demonstrated the second sub-group was constituted by analogues of the 11-hydroxysulfated GC1/GC2, while the third sub-group was constituted by analogues of GC3, which lack the 11-hydroxysulfate. In addition to GC1/GC2 and GC3, novel analogues differing by 16u could be related, respectively, to the N1-hydroxyl analogues of GC1-GC3, designated GC4-GC6. A novel family of GC analogues, differing, by 16u from GC1-GC6, were hypothesized to possess an extra hydroxyl in the benzoate side chain, existing in both N1-hydroxylated and non-N1-hydroxylated variants, and tentatively designated GC1a-GC6a. The first sub-group was hypothesized to constitute an additional novel family of GC analogues with a hydroxysulfate group instead of the

  19. Paralytic shellfish toxins in the sea scallop Placopecten magellanicus on Georges Bank: Implications for an offshore roe-on and whole scallop fishery

    Science.gov (United States)

    DeGrasse, Stacey; Vanegas, Camilo; Conrad, Stephen

    2014-05-01

    To protect public health from the potential risk of paralytic shellfish poisoning (PSP) in sea scallops, Placopecten magellanicus, from the Atlantic offshore U.S. waters of Georges Bank, harvesting of roe-on or whole scallops is banned. Only adductor muscles may be sold if harvested from Georges Bank, Gulf of Maine, or the PSP closure areas as far west as 71° West Longitude. Given the limited toxicity data available for sea scallops from this region both prior to and subsequent to implementation of this management strategy, this study sought a more extensive spatial and temporal evaluation of sea scallop gonad and viscera toxicities that would inform management decisions related to the roe-on and whole scallop fishery. Both overall toxicity and toxin composition were measured for sea scallop gonads and viscera collected from 232 stations in 2007 and 23 in 2010. Overall toxicity was assessed using two screening methods: field-deployable Jellett Rapid Tests (JRT) and quantitative, laboratory-based receptor binding assays (in 2007). Additionally, a quantitative liquid chromatography with fluorescence detection (LC-FD) method was used to determine toxin composition and overall toxicity (in 2010). The at-sea qualitative JRT screening tool results, whereby a positive indicated the sample contained at least 40 μg saxitoxin (STX) equivalents 100 g-1, were often inconsistent with results obtained using the quantitative methods. Sea scallop viscera toxicity represented the majority of toxin load in the organism and was often in excess of the regulatory guidance level. Sea scallop gonads accounted for a small percentage of total toxicity, but at times reached unsafe levels. Toxin composition in both the gonads and viscera was dominated by STX and gonyautoxin 2/3, as has been reported in previous studies. No predictive indices of gonad toxicity were found. Results at this time do not support a roe-on or whole scallop fishery on Georges Bank. While access restrictions to

  20. Urbanization and Condition of Urban Slums in India

    Directory of Open Access Journals (Sweden)

    Digambar Abaji Chimankar

    2016-08-01

    Full Text Available The present paper attempted to study the urbanization in India and condition of urban slums in terms of water, sanitation, electricity, garbage collection and health care, and education which are supposed to be basic minimum needs for the slum dwellers. India is going through the process of rapid urbanization because of industrialization like other third world countries.  The percent of urbanization increase from 27.8 percent in 2001 to 31.1 percent in 2011 census. The increase in the percentage of population in urban areas is because of natural growth, rural to urban migration and the reclassification of village and towns. The share of the slum population in the total urban population of the country was 18.3 percent in 2001 while in 2011 it was 17.4 percent. The condition of urban slums in India is to be improved so as to make them better for living.

  1. Economic Dimensions of Urban Agriculture in the Context of Urban ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Economic Dimensions of Urban Agriculture in the Context of Urban Poverty ... price crisis and the threat of climate change to traditional sources of food security. ... its 2017 call for proposals to establish Cyber Policy Centres in the Global South.

  2. Lesotho - Urban and Peri-Urban Water and Metolong Dam

    Data.gov (United States)

    Millennium Challenge Corporation — Early on, MCC and the evaluator decided to focus the Urban and Peri-Urban Water evaluation on Package 1 infrastructure, which benefited Maseru and Mazenod. MCC later...

  3. Towards urban mobility designs

    DEFF Research Database (Denmark)

    Lanng, Ditte Bendix; Harder, Henrik; Jensen, Ole B.

    2012-01-01

    for the wayfarers who use the site. The data for our work concerns a transit site in the 1970s urban district of Aalborg Øst, Denmark. - We set out by introducing our approach to the site. - Second, we examine the functional layout of the transit site in Aalborg Øst and outline the design challenge which we......Functionalist traffic design aims at a rational organisation of movement from A to B in a segregated and uniform physical environment. Such urban areas have been criticized for being exclusively functional and lacking sensuous and social qualities. Recent research on mobilities challenges the more...... insights on functional urban planning, on embodied practices and experiences of wayfaring, and on concrete small scale design concerns. We emphasise an integrated design agenda for those ordinary transit sites which is concerned with functional issues as well as the quality of life on the ground...

  4. Urban diffusion problems

    International Nuclear Information System (INIS)

    Hanna, S.R.

    1976-01-01

    It is hoped that urban diffusion models of air pollutants can eventually confidently be used to make major decisions, such as in planning the layout of a new industrial park, determining the effects of a new highway on air quality, or estimating the results of a new automobile emissions exhaust system. The urban diffusion model itself should be able to account for point, line, and area sources, and the local aerodynamic effects of street canyons and building wakes. Removal or transformations due to dry or wet deposition and chemical reactions are often important. It would be best if the model included meteorological parameters such as wind speed and temperature as dependent variables, since these parameters vary significantly when air passes from rural surfaces over urban surfaces

  5. Urban agriculture in Botswana

    Directory of Open Access Journals (Sweden)

    Aloysius Clemence Mosha

    2016-02-01

    Full Text Available Botswana, a middle-income country, is experiencing a sluggish economic growth and a rapid urbanisation which has brought in its wake high unemployment, poverty and food insecurity. This has led some people to engage in subsistence and commercial urban and peri-urban agriculture (UPA to address these problems. However, in spite of its known advantages, uptake of UPA has been low for a number of reasons including: high GDP before the economic meltdown of recent years; a harsh climate; lack of water; poor access to land; and over-reliance on generous government handouts. Nevertheless, the extent of its practice and its contribution to food security – albeit modest – shows that it is a sector that needs to be encouraged and supported. Both central and local government can play a big role by providing land and infrastructure, and also by implementing an enabling policy and regulatory environment which promotes small- and medium-scale urban food production.

  6. Assembling urban riskscapes

    DEFF Research Database (Denmark)

    Blok, Anders

    2016-01-01

    model of climate resilience, within unequal local–global assemblages of urban planning and power. This work of resilience-building is shown to revolve around Surat-based economic and political elites, who deploy mobile consultancy knowledges to render particular urban ‘riskscapes’ (in)visible, in ways...... knowledge practices, I suggest, link into and enable different visions and commitments to competing ‘scales of change’ for the city. By thus allowing us to grasp the situated tools, practices and knowledges through which ‘large-scale’ processes of urban change—development, climate resilience, justice...... conducive to specific forms of middle-class development. In turn, the article shows how this ‘official’ work of resilience-building is challenged and contested by fragmented civic–professional publics, mobilizing their own versions of counter-expertise towards alternative riskscapes. These heterogeneous...

  7. Nordic urban nature recreation

    DEFF Research Database (Denmark)

    Cole, Scott; Lindhjem, Henrik; Zandersen, Marianne

    the associated nonmarket welfare benefits. The study stresses the need to collect user data to better understand visitation patterns, which can be combined with valuation methods to provide evidence of economic benefits associated with e.g., hiking, cycling, skiing, paddling and other recreation activities. Once......The Nordic countries continue to experience growth of urban areas, which provides benefits like economic growth, but also imposes economic costs in terms of reduced ecosystem services. This report focuses on urban nature recreation and highlights economic methods and data that can help capture...... these benefits are visible, decision-makers will have a better basis to balance economic growth with the environmental costs it imposes on urban ecosystem services....

  8. Performative Urban Architecture

    DEFF Research Database (Denmark)

    Thomsen, Bo Stjerne; Jensen, Ole B.

    The paper explores how performative urban architecture can enhance community-making and public domain using socio-technical systems and digital technologies to constitute an urban reality. Digital medias developed for the web are now increasingly occupying the urban realm as a tool for navigating...... the physical world e.g. as exemplified by the Google Walk Score and the mobile extension of the Google Maps to the iPhone. At the same time the development in pervasive technologies and situated computing extends the build environment with digital feedback systems that are increasingly embedded and deployed...... using sensor technologies opening up for new access considerations in architecture as well as the ability for a local environment to act as real-time sources of information and facilities. Starting from the NoRA pavilion for the 10th International Architecture Biennale in Venice the paper discusses...

  9. Participatory urban renewal

    Directory of Open Access Journals (Sweden)

    Drago Kos

    2005-01-01

    Full Text Available The article consists of two parts. The first deals with the theoretical framework of urban rehabilitation. Literature provides the basis for a conclusion, which is that the key issue in rehabilitation projects is legitimate negotiation of various interests between participating individuals and institutions. In the second part this presentation and analyses of events that took place at the urban design workshop organised within the framework of the research project Renewal of housing estates in Ljubljana, provide experiential confirmation of the starting thesis. We established that the directly involved residents were willing to actively participate in rehabilitation procedures, however the process is never triggered, because of insufficient capacities in institutional frameworks. In conclusion several real proposals are shown, namely, how to surmount obstacles in urban rehabilitation and especially in larger housing estates built after World War 2.

  10. Rural versus Urban

    DEFF Research Database (Denmark)

    Schøning, Signe Wedel

    and take position within larger social structures of unequal power structures through such employment. The adolescents did not explicitly discuss power relations between urban and rural Denmark in their everyday social encounters, but when they employ Stylised vestjysk and Stylised københavnsk......This ethnographic project discerns how rural adolescents living in West Jutland, Denmark, carry out their daily lives under globalised conditions. The project shows how the young speakers (re)activate, align with and discard ideological perceptions of rural and urban Denmark. By investigating......, they continuously ascribe low social status to the former and high social status to the latter. Thus, the overall picture is one reproducing urban Denmark as a powerful and prestigious centre, whereas rural Denmark is disempowered....

  11. Sustainable Urban Fringes - Connecting Urban and Rural : Final report of the SURF project

    NARCIS (Netherlands)

    Bruijn, de T.J.N.M. (Theo); Haccoû, H.A. (Huib); Leslie, A. (Allison); Lier, G. (Goos); Littlewood, S. (Stephan); Oldejans, R. (Rolf); Thomas, K. (Kevin); Vries, de B.J. (Bauke); Watt, E. (Emma); Wishardt, M. (Michelle)

    2012-01-01

    What happens at the urban edge and the SURF aspiration to influence it? Projects in the urban fringe Urban fringe governance Integrated policy guidelines and approaches towards urban fringe planning and management The future management of the urban fringe

  12. African urbanization in metropolitan South Africa--differential urbanization perspectives.

    Science.gov (United States)

    Geyer, H S

    1993-07-01

    "As a potentially important urban development policy consideration, attention is focused in this paper on differential urbanization trends in South Africa at the metropolitan level. Recent informal urban settlement patterns of the African population within the major metropolitan areas are contrasted against these differential urbanization trends to determine the implications of both for residential development in the metropolitan areas during the post-apartheid era." excerpt

  13. Analysis of Global Urban Temperature Trends and Urbanization Impacts

    Science.gov (United States)

    Lee, K. I.; Ryu, J.; Jeon, S. W.

    2018-04-01

    Due to urbanization, urban areas are shrinking green spaces and increasing concrete, asphalt pavement. So urban climates are different from non-urban areas. In addition, long-term macroscopic studies of urban climate change are becoming more important as global urbanization affects global warming. To do this, it is necessary to analyze the effect of urbanization on the temporal change in urban temperature with the same temperature data and standards for urban areas around the world. In this study, time series analysis was performed with the maximum, minimum, mean and standard values of surface temperature during the from 1980 to 2010 and analyzed the effect of urbanization through linear regression analysis with variables (population, night light, NDVI, urban area). As a result, the minimum value of the surface temperature of the urban area reflects an increase by a rate of 0.28K decade-1 over the past 31 years, the maximum value reflects an increase by a rate of 0.372K decade-1, the mean value reflects an increase by a rate of 0.208 decade-1, and the standard deviation reflects a decrease by rate of 0.023K decade-1. And the change of surface temperature in urban areas is affected by urbanization related to land cover such as decrease of greenery and increase of pavement area, but socioeconomic variables are less influential than NDVI in this study. This study are expected to provide an approach to future research and policy-planning for urban temperature change and urbanization impacts.

  14. Urban acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

  15. Gwangju Urban Strategies

    DEFF Research Database (Denmark)

    2016-01-01

    The book is a reflective representation of students work in Studio Context Spring 2016 at Aarhus School of Architecture conserning the city of Gwangju, Republic of Korea. The design works are considered to be genetic urban acupuncture, which is intended to develop over time.......The book is a reflective representation of students work in Studio Context Spring 2016 at Aarhus School of Architecture conserning the city of Gwangju, Republic of Korea. The design works are considered to be genetic urban acupuncture, which is intended to develop over time....

  16. Urban Interaction Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Bermúdez, Juan Carlos Carvajal; Fernández, Manu

    This book is an effort to explore the newly emerging field of urban interaction design that addresses these issues. In the first part of the book, 'Foundations', we look into its origins. Where do its practitioners come from? How are they working together? What methodologies do they bring...... to the table? What are the key concepts they are addressing in their work? In the second part of the book named 'Trends', we go into current developments in the networked city and how urban interaction design as a field addresses these. Taken together, these sections will not give the definite definition...

  17. Urbanity as military loot

    Directory of Open Access Journals (Sweden)

    Miloš Bobić

    1993-01-01

    Full Text Available While discussing on a series of examples concerning urbanity, the author presents the present reality of Eastern Europe cities (countries and a parallel to the events in the Balkans. The reasons for civilisational unsuccess can be found in the devaluation of constant values and the incomprehensible multilateral linking if particular civilisational elements or deliberate destruction of negatively annotated ways of living. He continues with questions concerning: the relationship between a town and its surroundings, the iconization of inner cities or the character of particular city areas, the changing urban elite following present social changes, especially in culture and the culture of city life.

  18. Modeling urban fire growth

    International Nuclear Information System (INIS)

    Waterman, T.E.; Takata, A.N.

    1983-01-01

    The IITRI Urban Fire Spread Model as well as others of similar vintage were constrained by computer size and running costs such that many approximations/generalizations were introduced to reduce program complexity and data storage requirements. Simplifications were introduced both in input data and in fire growth and spread calculations. Modern computational capabilities offer the means to introduce greater detail and to examine its practical significance on urban fire predictions. Selected portions of the model are described as presently configured, and potential modifications are discussed. A single tract model is hypothesized which permits the importance of various model details to be assessed, and, other model applications are identified

  19. Urbanism and Racial Attitudes: A Test of Some Urban Theories.

    Science.gov (United States)

    Wilson, Thomas C.

    1984-01-01

    National survey data are used to test the relationship between urbanism and racial attitudes among Whites, and a liberalizing effect of urbanism is found. It appears that urbanism liberalizes racial attitudes by increasing equal-status, cooperative, and relatively personal contact between members of racial subcultures. (Author/RDN)

  20. Shrinking Cities or Urban Transformation

    DEFF Research Database (Denmark)

    Laursen, Lea Louise Holst

    Shrinking Cities or Urban Transformation is a PhD-thesis conducted at the Department of Architecture and Design, Aalborg University in the period 2004-2008. The PhD concerns the spatial changes that emerge in contemporary urbanity. Contemporary urbanity can among others be characterized as both...... growing and declining. On the one hand, a concentration of the urban into a highly urbanized nodal point is happening and on the other a deconcentration of the urban fabric in declining territories is taking place. The starting point for the dissertation is the term shrinking cities, which has been...... investigation of the cases Baltimore and Denmark is conducted. This shall shed light upon whether the theoretical assumptions correspond to what is happening in the real world. The introduction of the term urban transformation is the result of these investigations and a response to shrinking cities. Urban...

  1. CONCLUSIONS Urban Children and Adolescents

    Indian Academy of Sciences (India)

    CONCLUSIONS Urban Children and Adolescents. Increasing prevalence of overweight and obesity and measures of regional (central) adiposity. High prevalence of markers of dysmetabolic state in urban adolescents. ~10% prevalence of dysglycemia in overweight / obese school children.

  2. Urbanization and Third World stability

    Energy Technology Data Exchange (ETDEWEB)

    Bienen, H

    1984-07-01

    This essay reviews images of urbanization that have been held by academics and activists, including revolutionary leaders. It examines the methodology and findings of case studies in Nigeria, Mexico, Peru, Brazil, Kenya, Turkey, Malaysia and other countries with the aim of determining how well suited are the data and theories for assessing the relationship between urbanization and political stability. The review examines the following topics: migration; political participaton and the urban poor; radical parties and urban violence; the over-urbanization thesis; class and ethnicity. It especially evaluates the role of so-called urban marginals in urban political life and concludes that the evidence is overwhelming that there is no widespread culture of poverty or culture of apathy among the urban poor in developing countries. 119 references.

  3. Informal Urban Development in Cairo

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Petersen, Mads Dines

    2017-01-01

    The city of Cairo, Egypt, currently experiences rapid urban growth. Large parts of the city expand without formal urban planning. This results in large-scale informal and unplanned development. In addition, the resulting urban fabric and individual buildings feature severe deficiencies when...... it comes to the basic quality of urban space, ventilation and daylight. While retrofitting already built-up areas would be a huge challenge, some minor improvements might be possible in future development even within the current mode of production of these spaces. In recent years, parametric design tools...... have opened up new possibilities for modelling in urban design. By way of a parametric design approach, different urban design parameters can be modified and new urban space scenarios can be rendered three dimensionally in almost real time. In short, this is parametric urban design. It opens up...

  4. Urban Farm Business Plan Handbook

    Science.gov (United States)

    The Urban Farm Business Plan Handbook (this document) provides guidance for developing a business plan for the startup and operation of an urban farm. It focuses on food and non-food related cultivated agriculture.

  5. The Inner Urban Edge

    Science.gov (United States)

    Ferebee, Ann; Carpenter, Edward K.

    1974-01-01

    In this article, renewal of the inner urban edge is discussed. Norfolk (Virginia) is attempting to blur the difference between old and new neighbor hoods through zoning and architectural controls. Cincinnati (Ohio) is developing an environmentally sound hillside design. Reading (Pennsylvania) is utilizing old railyards for greenbelts of hiking and…

  6. Ecology in Urban Education.

    Science.gov (United States)

    Johnson, Letitia K.; Ryan, Michael

    In this course guide to the teaching of urban ecology, six learning activities on the following topics are outlined: (1) city location and growth; (2) an in-depth study of New Orleans; (3) city shape and structure; (4) size and spacing of cities; (5) cities with special functions; (6) local community study. Educational objectives for each activity…

  7. Qualifying Urban Landscapes

    DEFF Research Database (Denmark)

    Juel Clemmensen, Thomas; Daugaard, Morten; Nielsen, Tom

    This paper is based on a research project aimed at contributing to the qualification of the aesthetical value of the contemporary urban landscape. We see our work as part of a tradition within the architectural profession of making explorative projects, which combines analysis of the contemporary...

  8. in urban Ghana

    African Journals Online (AJOL)

    Agribotix GCS 077

    issues—issues that are of great significance to formal state institutions. ... a number of unorthodox crime-fighting and -response formations, many of ... Our paper contributes to the nascent criminology literature in Africa by presenting a case study ...... Hove, M., Ngwerume, E. T. & Muchemwa, C. (2013): The urban crisis in ...

  9. Urban Mass Transportation.

    Science.gov (United States)

    Mervine, K. E.

    This bibliography is part of a series of Environmental Resource Packets prepared under a grant from EXXON Education Foundation. The most authoritative and accessible references in the urban transportation field are reviewed. The authors, publisher, point of view, level, and summary are given for each reference. The references are categorized…

  10. Ambiguity in urban belonging

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin; Simonsen, Kirsten

    2015-01-01

    mapping of life as an ethnic minority in the city. It revolves around three issues. First, it focuses on the narrators’ experiences of exclusions and blockages in everyday life. This is followed by a focus on urban belonging emphasizing its differential character. Finally, the ambiguity of experiences...

  11. Better Urban Practice

    Institute of Scientific and Technical Information of China (English)

    YUAN YUAN

    2010-01-01

    @@ Greek philosopher Aristotle once said,"People come to cities for a living,and live in cities for a better life."The Urban Best Practices Area(UBPA)of the World Expo in Shanghai illustrates this year's Expo:For the first time,cities are provided with a chance to participate in the World Expo as independent players.

  12. Experiencing Performative Urban Space

    DEFF Research Database (Denmark)

    Marling, Gitte

    2012-01-01

    The focus of the article is performative urban spaces. The case study the Frederiksberg New City Centre. Here the atmosphere is produced via intentional designs and via different arrangements with sound, light and water. The designer has worked with different moods and experiences of moods. Some...

  13. Learning from Tokyo urbanism

    DEFF Research Database (Denmark)

    Greve, Anni

    2013-01-01

    from where to start. This leads into the leading concept of the article: the urban sanctuary. The second section goes back in history to the early modern era and, with point of departure in traveller’s reports, localises an experience of strangeness and familiarity when it comes to a distinct ritual...

  14. Improving the urban environment.

    Science.gov (United States)

    Rotibi, A

    1992-11-01

    An effective environmental sanitation program should encompass key features considered necessary for a primary health care (PHC) program such as availability, accessibility, affordability, acceptability, and practicability. Poor housing conditions give rise to stress, delinquency, and crime, as well as to helminthic and other parasitic infestations. In Africa, urbanization has accelerated since the 1950s because of rural-urban migration. In Nigeria new housing construction has been poor, with inadequate provision of physical facilities and community services in residential areas. Overcrowding is rampant, with occupancy rates of 2-3 persons per room recorded for many cities including Owerri, Abba, Warri and Ontisha. In a survey of rooming-house facilities in Lagos, the average was 5-7 persons per room. 47% of households were living in just one rooms in Sokoto and 80% in the Lagos metropolitan area. An urban household survey by the Federal Office of Statistics found that 45% of households were without electricity. Similarly, 46% of households were found to be without running water, 29% obtained their water from wells, and 14% from streams. The inadequate provision of toilets poses major health risks. Many Nigerian cities lack efficient waste disposal systems: in Ibadan mounds of uncollected rubbish obstruct the roads. According to a Statistics Office survey 48% of refuse is estimated to be dumped illegally, while 23% is simply heaped in family compounds. A recently launched campaign on environmental sanitation is the start of improving the health of urban dwellers which could cut expenditure on curative health measures.

  15. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  16. Performative urban Spaces

    DEFF Research Database (Denmark)

    Marling, Gitte

    2010-01-01

    The article examines the background of contemporary life, i.e., the urban teoretical and analytical framework that shows the nee for a pluralistic and open city life. possibilities for developing performative places and spaces for social and cultural exchange will be suggested. The article...

  17. Into the urban wild

    DEFF Research Database (Denmark)

    Mollee, Eefke Maria; Pouliot, Mariéve; McDonald, Morag A.

    2017-01-01

    In sub-Saharan Africa, many people depend on natural resources for their livelihoods. While urbanisation causes landscape changes, little is known of how this process affects the use of wild plant resources by urban populations. This study contributes to addressing this knowledge gap by exploring...

  18. Modelling urban travel times

    NARCIS (Netherlands)

    Zheng, F.

    2011-01-01

    Urban travel times are intrinsically uncertain due to a lot of stochastic characteristics of traffic, especially at signalized intersections. A single travel time does not have much meaning and is not informative to drivers or traffic managers. The range of travel times is large such that certain

  19. Performative Urban design

    DEFF Research Database (Denmark)

    Kiib, Hans

    2010-01-01

    inner cities have been freed for new uses. This has created the basis for environmental improvements and a stronger, more diverse urban life. It is now possible to build new housing complexes and offices on the waterfront and in abandoned industrial areas; investments in cultural centers, cafes, and new...

  20. Urban design for mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2017-01-01

    . In this paper, we shall explore the potential for a better understanding of contemporary urban challenges through the cross-disciplinary approach of ‘Mobilities design’. The paper investigates how this notion is based on an understanding of materialities and social action that is framed under the heading...

  1. [Urban ecosystem services: A review].

    Science.gov (United States)

    Mao, Qi-zheng; Huang, Gan-lin; Wu, Jian-guo

    2015-04-01

    Maintaining and improving ecosystem services in urban areas and human well-being are essential for sustainable development and therefore constitute an important topic in urban ecology. Here we reviewed studies on ecosystem services in urban areas. Based on the concept and classification of urban ecosystem services, we summarized characteristics of urban ecosystem services, including the human domination, high demand of ecosystem services in urban areas, spatial heterogeneity and temporal dynamics of ecosystem services supply and demand in urban areas, multi-services of urban green infrastructures, the socio-economic dimension of ecosystem services supply and ecosystem disservices in urban areas. Among different urban ecosystem services, the regulating service and cultural service are particularly indispensable to benefit human health. We pointed out that tradeoffs among different types of ecosystem services mostly occur between supportive service and cultural service, as well as regulating service and cultural service. In particular, we emphasized the relationship between landscape design (i.e. green infrastructure) and ecosystem services supply. Finally, we discussed current gaps to link urban ecosystem services studies to landscape design and management and pointed out several directions for future research in urban ecosystem services.

  2. Green infrastructure and urban sustainability

    Science.gov (United States)

    Hagishima, Aya

    2018-02-01

    Temperature increase in urban areas due to the urban heat island as well as the global climate change inevitably raises the peak load supply for space cooling as well as the risk of heat-related illness in hot climate. This paper provides the comprehensive review of the thermal mitigation effect of urban vegetation based on the field observations.

  3. Collaborative planning via urban agriculture

    NARCIS (Netherlands)

    Oyuela Ochoa, Andrea; Valk, van der Arnold

    2017-01-01

    The city of Tegucigalpa as it is today is a result of the rural–urban migration phenomenon triggered in the 1950s across Honduras and the accompanying blueprint models of urban development at the time. Nowadays, the city is dominated by issues such as social disparity, urban violence, and

  4. Teaching urbanism : the Delft approach

    NARCIS (Netherlands)

    Nijhuis, S.; Stolk, E.H.; Hoekstra, M.J.

    2016-01-01

    The Department of Urbanism at the Faculty of Architecture and Built Environment at the Delft University of Technology has a long tradition in educating generations of internationally oriented designers, planners and researchers in urbanism. Here the domain of urbanism is defined as an

  5. Gainesville's urban forest canopy cover

    Science.gov (United States)

    Francisco Escobedo; Jennifer A. Seitz; Wayne Zipperer

    2009-01-01

    Ecosystem benefits from trees are linked directly to the amount of healthy urban forest canopy cover. Urban forest cover is dynamic and changes over time due to factors such as urban development, windstorms, tree removals, and growth. The amount of a city's canopy cover depends on its land use, climate, and people's preferences. This fact sheet examines how...

  6. India in the urban revolution

    NARCIS (Netherlands)

    Nijman, J.

    2012-01-01

    In the past decade, India’s development has featured rapid economic growth and unprecedented urbanization. Using preliminary results from the 2011 Census and recent macro-economic data, this paper analyses the relationship between urbanization and economic development in India. While urbanization is

  7. Urbanization in contemporary Arab Gulf states.

    Science.gov (United States)

    Qutub, I Y

    1983-01-01

    Urbanization in the Arab Gulf states of Bahrain, Kuwait, Oman, Qatar, and the United Arab Emirates is analyzed. Topics discussed include the historical background to urbanization; current demographic trends in the region; urban characteristics and growth; socioeconomic factors influencing urbanization, with an emphasis on labor force structure; future urban strategy; and the need for urban research.

  8. Urban Agriculture, Commons and Urban Policies: Scaling up Local Innovation

    Directory of Open Access Journals (Sweden)

    François Mancebo

    2016-04-01

    Full Text Available May urban agriculture be the cornerstone that helps reconfigure more sustainable cities and if so, under which conditions? And if so, what type of urban agriculture? Such are the two issues underlying this article. Why not counteracting urban sprawl by fostering what could be called “rural sprawl”, by introducing nature and rural characteristics such as farming within the city, in its interstitial areas and wastelands? In this perspective, urban agriculture becomes a common good, bringing people together and reshaping the whole urban fabric that would eventually propose a radical remaking of the urban. Urban agriculture lends particularly well to long-lasting urban policies, especially those turning environmental “bads”—such as brownfields and wastelands—into environmental “goods” and urban amenities. Urban agriculture in interstitial abandoned urban areas may be one of cities’ main seedbeds of creative innovation. It is all about the right to decide and the power to create, renewing and deepening what Henri Lefebvre called The Right to the City.

  9. Urbanization and Sub-urbanization Processes Over Time and Space

    International Nuclear Information System (INIS)

    Obudho, R.A.

    1999-01-01

    Until recently, it was thought that Kenya would be an overwhelmingly rural country and that urbanization would not be a problem, because it was associated with modernization and industrialization. Both Government of Kenya (GoK) and international donor agencies fostered rural developmental and agricultural-based strategies without paying attention to rapid rates of urbanization. Today, the high rate of urbanization in Kenya has been added to the long list of potentially devastating development problems that must be addressed. The fundamental problem is that, the urban population is growing very fast while the economic growth and development transformations necessary to support it enhance the quality of urban life are not occurring as rapidly. The new planning strategy for Kenya is to move beyond isolated projects, that emphasize shelter and residential infrastructure towards integrated urban-wide effort that promote urban productivity and reduce constraints on efficiency

  10. Introducing Urban Cultural Heritage Management into Urban Planning Management

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>1. Concept comparison of urban cultural heritage management and urban planning management 1.1 Urban cultural heritage managementUrban cultural heritage management is an important component of cultural heritage management which is a systematic conser-vation to maintain the cultural value of cul-tural heritages so as to meet the enjoyment demand of the current or future generations. At present, the cultural heritage conserva-tion principles have been defined by many worldwide laws or charters, such as the Venice Charter of ICOMOS, the UNESCO World Heritage Convention, etc., and have been brought into legislation or policies in many countries. The fi nal goal of urban cul-tural heritage management is to find a real sustainable approach to manage heritages, which could benefit the heritages them-selves, the heritage managers and the local communities as well. Cultural heritage man-agement includes the management of urban cultural heritages, that of natural heritages in non-urban areas and that of intangible cultural heritages.1.2 Urban planning managementUrban planning management is a type of urban management. From the practical viewpoint, urban management should be an overall management which includes urban planning management, urban infrastructure and public facility management, urban en-vironment and public order management, etc., takes urban infrastructures and public resources as management object, and ischaracterized by the goal of exerting the comprehensive effects of economy, society and environment. While from the techni-cal viewpoint, urban planning management refers to the planning management executed by urban governments based on the relevant laws and regulations, including the manage-ment of urban land-use and that of different types of constructions. It actually means the organizing, guiding, controlling and coordinating process focusing on different construction projects in cities. The urban cultural heritage mentioned here includes all the physical

  11. Finding Urban Identity through Culture-led Urban Regeneration

    Directory of Open Access Journals (Sweden)

    Kyu Hong Hwang

    Full Text Available ABSTRACT: A city experiencing a cycle from growth to decline cannot maintain sustainable development without the type of urban identity that could be consolidated by culture-led urban regeneration. A plan for urban regeneration in a declining urban area should be practiced partially or on the whole according to the characteristics of the community. By transforming a low-value and deteriorated area into a highly valued district, the local community can simultaneously restore its social pride, revive the local economy, and realize an urban identity.Firstly, this paper examines urban decline in order to better understand urban regeneration and the need for multidisciplinary management, and also, by considering the necessity for and universal types of urban regeneration, investigates the characteristics of culture-led urban regeneration as a tool for realizing socio-economic revival and urban identity. In particular, this study suggests the action techniques and benchmarking points for urban regeneration by analyzing cases of culture-led urban regeneration in Korea. Three subjects were considered as case studies in this paper: 1 Hanok village in Jeonju city, which changed from a twilight zone to a tourist attraction; 2 Changdong district in Changwon city, which recovered from an area of declining and dark alleyways that had been the hub for arts and culture in the 1970s to become a new artist village; and 3 Cheongju city, which is being transformed from an idle industrial facility into a cultural space. This thesis suggests the implementation process of culture-led urban regeneration to find an urban identity through analysis of the causes of urban decline, the methods of regeneration, and the results of urban regeneration in the three aforementioned cases. In the conclusion section of this paper, the implementation process for culture-led urban regeneration is summarized as consisting of 5 phases: Phase 1, the diagnosis of decline; Phase 2

  12. "Urban, but Not Too Urban": Unpacking Teachers' Desires to Teach Urban Students

    Science.gov (United States)

    Watson, Dyan

    2011-01-01

    This study explores 16 novice, urban-trained teachers' evaluations of their current schools. Findings suggest that teachers used the perceived behaviors, values, and beliefs of students to measure how urban a student was and, therefore, to guide their expectations and satisfaction of their placements. The less urban the students were perceived to…

  13. Study of polonium and lead in shellfish (Mytilus Edulis) from NORM discharge area of Aberdeen Bay and Ythan Estuary of Scotland and radiological impact to the local people and environment

    International Nuclear Information System (INIS)

    Satyajit Ghose; Brian Heaton

    2005-01-01

    can be made it is essential that the release rates of the nuclides from the discharges are known. If polonium becomes available in the marine environment from these discharges they will contribute to the impact on the environment. In order to evaluate the possible radiological impact to the local people and the environment, a comprehensive study was set up in order to determine the full extent of TENORM and NORM outputs and the impact that these radionuclides were having on the environment. The main aim of this study concerned the quantification of the levels of 210 Po and 210 Pb in shellfish species and other environmental samples taken from around Aberdeen, and use them as bio-indicators for the analysis of Polonium-210 and Lead-210 with particular emphasis on the seasonal variation in Mytilus edulis at one site of Ythan estuary. There was a supplementary programme undertaken to some dose assessment work relevant to human consumption of shellfish. Additionally, the study of the distribution of 210 Pb and 210 Pb between the filtered, particulate phases, sediment and mussels can provide interesting in formation about their behaviour in this aquatic system. Experimental Radiochemical separation and α Spectrometer with Dual surface barrier detector was used to count the polonium a particles. A Perspex disc holder for polonium deposition was specially designed to be held in a stirrer and to fit inside a 150-200 ml breaker. The holder provides positive protection to one face of the silver disc. Silver disc with a thickness of 0.2 mm and 25 mm in diameter was used for 210 Po spontaneous deposition. Results: The measured 210 Po and 210 Pb concentrations and 210 Po/ 210 Pb activity ratio in filtrate water, sediment, particulate matter and mussel samples are reported. Some results are presented in Figure 1 and Table 1. Correlations between 210 Po and 210 Pb concentrations in mussel and related environmental samples, mussel wet weight and size are presented. The Condition

  14. Interfacial modulation of urban affect

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban culture can increasingly be understood as interface culture (Munster) in which urban design, cultural institutions and architecture increasingly operate as affective interfaces distributing and mediating human perception, consumption and social encounters. As noted by Amin and Thrift (2002......, Massey 2006), they also exclude in depth social and human interaction. Through analysis of three examples of urban affective interfaces (The High Line in New York, Superkilen in Copenhagen and Stålsat By, Frederiksværk, the paper examines how affective urban interfaces modulate and mediate urban...... environments as bodily and sensorial experiences. It asks what is mediated through the interface – whether the. It also asks, what is excluded when urban environments become affective interfaces in the global networked city. Whereas urban interface collect and distribute the bodily and sensible in relational...

  15. Interpreting Sustainability for Urban Forests

    Directory of Open Access Journals (Sweden)

    Camilo Ordóñez

    2010-06-01

    Full Text Available Incisive interpretations of urban-forest sustainability are important in furthering our understanding of how to sustain the myriad values associated with urban forests. Our analysis of earlier interpretations reveals conceptual gaps. These interpretations are attached to restrictive definitions of a sustainable urban forest and limited to a rather mechanical view of maintaining the biophysical structure of trees. The probing of three conceptual domains (urban forest concepts, sustainable development, and sustainable forest management leads to a broader interpretation of urban-forest sustainability as the process of sustaining urban forest values through time and across space. We propose that values—and not services, benefits, functions or goods—is a superior concept to refer to what is to be sustained in and by an urban forest.

  16. URBAN POLITICS: KEY APPROACHES

    Directory of Open Access Journals (Sweden)

    Ledyaeva Ol'ga Mikhaylovna

    2012-10-01

    Full Text Available Several approaches that underlie urban politics are discussed in the paper. They include neo-liberalism, political economy discourse, elitist/pluralist debates, and postmodernism. The neoliberal approach focuses on the limited role of the state and individual responsibility. The legal framework protects both the rights and responsibilities of individuals and regulates the operation of the market. It is the market that fosters individual choices and provides goods and services by virtue of the processes which are flexible, efficient and transparent. The political economy approaches (regulation theory, public choice theory, neo-Marxism explain urban politics via the analysis of national and international economic processes and changes in contemporary capitalism. Changes in national and international economies determine what solutions are possible. The discourse has been influenced by the debate on globalization of capital and labour markets. Modern elitism and neopluralism are represented by theories of "growth machines" and "urban regimes". The former focuses on bargaining alliances between political and business leaders in order to manage the urban system and to promote its growth. The latter develops neopluralist explanations of power within local communities with an emphasis on the fragmented nature of the government where local authorities lack comprehensive governing powers. Postmodernism views the city as the site of the crisis of late capitalism which leads to segregation of neighbourhoods onto prosperous areas and ghettoes. In contrast to the modern city, the postmodern city is not defined by its industrial base; rather, it is determined by its consumerist environment of malls and museums, characterized by revivalist architecture. At the same time, the suburban shopping mall and a motorway network make nonsense of the idea of the city as a unique and well-defined space. These and other approaches encompass a wide spectrum of possibilities

  17. Paralytic shellfish toxins in the chocolata clam, Megapitaria squalida (Bivalvia: Veneridae, in Bahía de La Paz, Gulf of California

    Directory of Open Access Journals (Sweden)

    I Gárate-Lizárraga

    2004-09-01

    Full Text Available Occurrence and toxic profiles of paralytic shellfish toxins (PST in the chocolata clam Megapitaria squalida were investigated. From December 2001 to December 2002, 25 clams were obtained monthly from Bahía de La Paz, Gulf of California. Additionally, net (20 µm and bottle phytoplankton samples were also collected to identify toxic species. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. Toxicity in the clam was low and varied from 0.14 to 5.46 µg/STXeq/100 g. Toxicity was detected in December, March, April, June, and August. Toxin profile was composed mainly by STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX and B1. Gymnodinium catenatum was the only PST-producing dinoflagellate identified in the phytoplankton samples throughout the study period. G. catenatum was observed mainly in net samples from December 2001 to December 2002; however, in bottle samples, G. catenatum was only observed in five months. Highest abundance (2 600 cells l-1 was observed in March and the lowest (160 cells l-1 in June. G. catenatum mainly formed two-cell chains and rarely four or eight. The presence of PST in net phytoplankton samples support the fact that G. catenatum is the main source of PST in the clams. This study represents the first report of PST toxins in the chocolata clam from Bahía de La PazSe investigó la ocurrencia así como los perfiles de toxinas paralíticas (PST en la almeja chocolata Megapitaria squalida (Sowerby, 1835, de la cual se recolectaron mensualmente 25 ejemplares de diciembre del 2001 a diciembre del 2000 en La Bahía de La Paz, Golfo de California. Simultáneamente, se obtuvieron muestras de fitoplancton de botella y de red (20 µM para identificar especies tóxicas, así como para detectar la presencia de toxinas paralíticas. Las toxinas se analizaron por HPLC con una oxidación post-columna y detección fluorescente. La toxicidad en las almejas fue baja y varió de 0.14 a 5.46 µg/STXeq/100 g y se

  18. Estimating the contribution of N-sulfocarbamoyl paralytic shellfish toxin analogs GTX6 and C3+4 to the toxicity of mussels (Mytilus galloprovincialis) over a bloom of Gymnodinium catenatum.

    Science.gov (United States)

    Costa, Pedro Reis; Moita, Teresa; Rodrigues, Susana Margarida

    2014-01-01

    Gymnodinium catenatum, a dinoflagellate species with a global distribution, is known to produce paralytic shellfish poisoning (PSP) toxins. The profile of toxins of G. catenatum is commonly dominated by sulfocarbamoyl analogs including the C3+4 and GTX6, which to date has no commercial certified reference materials necessary for their quantification via chemical methods, such as liquid chromatography. The aim of this study was to assess the presence of C3+4 and GTX6 and their contribution to shellfish toxicity. C3+4 and GTX6 were indirectly quantified via pre-column oxidation liquid chromatography with fluorescence detection after hydrolysis conversion into their carbamate analogs. Analyses were carried out in mussel samples collected over a bloom of G. catenatum (>63×10 3 cellsl -1 ) in Aveiro lagoon, NW Portuguese coast. Concentration levels of sulfocarbamoyl toxin analogs were two orders of magnitude higher than decarbamoyl toxins, which were in turn one order of magnitude higher than carbamoyl toxins. Among the sulfocarbamoyl toxins, C1+2 were clearly the dominant compounds, followed by C3+4 and GTX6. The least abundant sulfocarbamoyl toxin was GTX5. The most important compounds in terms of contribution for sample toxicity were C1+2, which justified 26% of the PSP toxicity. The lesser abundant dcSTX constitutes the second most important compound with similar % of toxicity to C1+2, C3+4 and GTX6 were responsible for approximately 11% and 13%, respectively. The median of the sum of C3+4 and GTX6 was 27%. These levels reached a maximum of 60% as was determined for the sample collected closest to the G. catenatum bloom. This study highlights the importance of these low potency PSP toxin analogs to shellfish toxicity. Hydrolysis conversion of C3+4 and GTX6 is recommended for determination of PSP toxicity when LC detection methods are used for PSP testing in samples exposed to G. catenatum. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Development and single-laboratory validation of a UHPLC-MS/MS method for quantitation of microcystins and nodularin in natural water, cyanobacteria, shellfish and algal supplement tablet powders.

    Science.gov (United States)

    Turner, Andrew D; Waack, Julia; Lewis, Adam; Edwards, Christine; Lawton, Linda

    2018-02-01

    A simple, rapid UHPLC-MS/MS method has been developed and optimised for the quantitation of microcystins and nodularin in wide variety of sample matrices. Microcystin analogues targeted were MC-LR, MC-RR, MC-LA, MC-LY, MC-LF, LC-LW, MC-YR, MC-WR, [Asp3] MC-LR, [Dha7] MC-LR, MC-HilR and MC-HtyR. Optimisation studies were conducted to develop a simple, quick and efficient extraction protocol without the need for complex pre-analysis concentration procedures, together with a rapid sub 5min chromatographic separation of toxins in shellfish and algal supplement tablet powders, as well as water and cyanobacterial bloom samples. Validation studies were undertaken on each matrix-analyte combination to the full method performance characteristics following international guidelines. The method was found to be specific and linear over the full calibration range. Method sensitivity in terms of limits of detection, quantitation and reporting were found to be significantly improved in comparison to LC-UV methods and applicable to the analysis of each of the four matrices. Overall, acceptable recoveries were determined for each of the matrices studied, with associated precision and within-laboratory reproducibility well within expected guidance limits. Results from the formalised ruggedness analysis of all available cyanotoxins, showed that the method was robust for all parameters investigated. The results presented here show that the optimised LC-MS/MS method for cyanotoxins is fit for the purpose of detection and quantitation of a range of microcystins and nodularin in shellfish, algal supplement tablet powder, water and cyanobacteria. The method provides a valuable early warning tool for the rapid, routine extraction and analysis of natural waters, cyanobacterial blooms, algal powders, food supplements and shellfish tissues, enabling monitoring labs to supplement traditional microscopy techniques and report toxicity results within a short timeframe of sample receipt. The new

  20. Sustainable Urban Biophilia: The Case of Greenskins for Urban Density

    Directory of Open Access Journals (Sweden)

    Grant Revell

    2014-08-01

    Full Text Available Green infrastructure ameliorates the urban heat island effect, contributes positively to liveability and enables sustainability in higher density urban environments. Greenskins (living architectures are a more specific form of green infrastructure, including green walls and green roofs, for dense urban areas. These offer a new approach for sustainable urban biophilia and some forms can be built using the ecological design principles of constructed wetlands. The paper compares findings from two urban centres in warm Mediterranean climates. In general from Adelaide, South Australia and more specifically from university collaborative projects on particular technical and social parameters necessary to sustain Greenskins in dense urban conditions in Fremantle, Western Australia. Results from trials of a prototype greywater Greenskin using vertical constructed wetland cells are reported. Through an experimental investigation of designing living green walls in urban Fremantle, this paper challenges the conventional “triple-bottom-line” approach to sustainable dense urban systems by addressing the greater aesthetic needs of sustainability and its thinking. Here landscape aesthetics looks to the collaborative fields of urban design, environmental engineering and landscape architecture to design new urban biophilic experiences and restorative landscapes for regenerative cultural pleasure, ecological responsibility, environmental stewardship and intellectual gain.

  1. The Contributions of Urban Landscape to Urban Life

    Directory of Open Access Journals (Sweden)

    Ahmet Tuğrul Polat

    2017-06-01

    Full Text Available The issues of urban and urbanization emerged after the industrial revolution. Thus, cities that have increased rapidly in population have become points of attraction for people. Over the past century, the world population has begun to gather quickly in urban areas. Cities are transforming into unhealthy living environments with distorted ecological balance, lost green areas and aesthetic qualities. The value of accessible green spaces in urban areas is increasing to the unprecedented levels. The green space system seen as a necessity in the cities have provided the emergence of the "urban landscape" phenomenon. The issue of urban landscape is now a very serious concept. The landscape change is moving along with the level of civilization. Primarily, guidance service should be offered for more efficient, comfortable and protective areas. An interdisciplinary approach is needed in the creation of urban spaces. In this study, the term of urban landscape was explained and the researches about the contributions of urban landscape to urban life were examined and suggestions were made about the subject.

  2. Urban networks of tomorrow

    International Nuclear Information System (INIS)

    Bothe, D; Kaufmann, T.

    2016-01-01

    The requirements for urban utility grids are subject to a considerable change. The diversification of the energy supply and the changing feed-in structure (central -> decentral) also influence the operation of the existing networks considerably. Therefore, the focus of future studies will be on the flexibility of energy supply and the energy-carrier-wide network analysis or planning. These aspects are addressed, among other things, within the URBEM project, with a focus on a holistic, interdisciplinary approach. On the basis of separately performed thermal and electrical network calculations an optimization task is defined (for example, minimization of operating resources, minimization of CO2 emissions) and solved under technical conditions. The scenarios for the period 2030 and 2050 developed in the URBEM project serve as the basis for the optimization. The results of the calculations show current utilization or bottlenecks in the supply networks as well as optimum future supply structures for development areas in urban areas. (rössner) [de

  3. Urban Quality Development & Management

    DEFF Research Database (Denmark)

    Lehmann, Martin; Fryd, Ole

    2008-01-01

    Purpose: The purpose of this article is to describe and discuss the development and the structure of a new international master on the subject of Urban Quality Development & Management, and explore the potential of the process and the outcome in serving as models adoptable by faculty at other......: Urban quality development and management is dependent on human resource development, institutionalised networks and confident exchange of knowledge, and must identify and incorporate multiple environmental, social, economic and cultural aspects. The authors find that at the core of innovative societies......, an interlinkage exists between practice (business, civil society, governance) and theory (research, education). The case illustrates how a new curriculum takes time to develop and implement and how it relies on confidence and trust between partners, in this case cities and universities, before being able to plant...

  4. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    of the structures of the networked urban mobilities and holds the potentials to change the future mobilities. References Bauman, Zygmunt. 2000. Liquid Modernity. Cambridge: Polity. Beck, Ulrich. 1992. Risk Society: Towards a New Modernity (Published in Association with Theory, Culture & Society). London: SAGE......In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... problems and side effects from concentration of consumption and contamination; and due to the shift from ownership to access it change our basic social cultural norms (Sayer 2005; Sayer 2011) about the ‘good’ life and social status (Freudendal-Pedersen 2007), commons and individuality, responsibility...

  5. Urban Stormwater Infiltration Perspectives

    DEFF Research Database (Denmark)

    Geldof, Govert; Jacobsen, Per; Fujita, Shoichi

    1994-01-01

    In urban areas there are many problems with water management: combined sewer overflows, peak flows, man-induced droughts, consolidation of the soil, damage from frost penetration, etc. It is preferable to look at all these problems in relation to each other, according the concept of integrated...... water management. This paper focuses on the possibilities for urban stormwater infiltration. The results of three studies are presented. The first study concerns the flooding of the Shirako River in Tokyo. It is shown that with the help of stormwater infiltration the floods can be reduced remarkably....... The second study concerns combined sewer overflows and the discharge from treatment plants for catchments in Denmark and the Netherlands. When looking at the total yearly discharge from the combined sewer and the treatment plant, it is shown that infiltration is more effective than detention. The third study...

  6. Urban Climate Risk Communities

    DEFF Research Database (Denmark)

    Blok, Anders

    2016-01-01

    of Beck’s forward-looking agenda for a post-Euro-centric social science, outlines the contours of such an urban-cosmopolitan ‘realpolitik’ of climate risks, as this is presently unfolding across East Asian world cities. Much more than a theory-building endeavour, the essay suggests, Beck’s sociology......Ulrich Beck’s cosmopolitan sociology affords a much-needed rethinking of the transnational politics of climate change, not least in pointing to an emerging inter-urban geography of world cities as a potential new source of community, change and solidarity. This short essay, written in honour...... provides a standing invitation for further transnational dialogue and collaborative empirical work, in East Asia and beyond, on what are, arguably, the defining challenges for the 21st century world of global risks....

  7. Sustainable urban development

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Christensen, Toke Haunstrup; Gram-Hanssen, Kirsten

    Sustainability in urban planning has a long history and it has been a widespread solution to build high and compact in order to minimise the need for transportation, land use and heating. Recent research, however, points towards the need for a supplementary approach which includes the consumer...... behaviour of the household. This approach necessarily has to work from below and include the citizens, as it is their daily practices that have to be challenged. This article reviews the literature of to what extent compact cities are the most sustainable and it use lifestyle interpretations of urbane forms...... to challenge the compact cities approach. As an alternative or supplementary approach the article introduce practice theory as a way to understand consumption and it gives examples on how this approach can be used to inspire local authorities to alternative and supplementary strategies of achieving sustainable...

  8. Urbanism of Detachment

    Directory of Open Access Journals (Sweden)

    Rahul Mehrotra

    2016-09-01

    Full Text Available In recent years, there has been an ex¬traordinary intensification of pilgrimage practices, which has translated into the need of larger and more frequently constructed urban structures for hosting massive gatherings. The case of the Kumbh Mela, a legendary Hindu festival in India, sets the standards for understanding alternative ways of building cities that are transitory and with a temporality aligned with the ephemeral nature of massive human flows. This massive cultural gathering, resulting in the biggest ephemeral mega city in the world accommodating 3 million pilgrims every 12 years, generates an extreme case that forces us to reflect deeply about the way we may think of future cities more broadly and from which we can extrapolate several lessons regarding more resilient, “open concept” of architecture, urban design and planning policy.

  9. Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Thomsen, Bo Stjerne

    2008-01-01

    The chapter explores how temporary architectural structures can become media for bottom-up approaches to urban development. Urban interactions in the city developed from the sidewalks were seen as locally bounded neighbourhoods. However, with the advent of contemporary network technologies....... In investigating architectural media-constructions the paper draws on the notion of ‘Capsular Civilization'. Arguing that architectural capsules in the cities' in-between spaces may become the media and places of meaningful interaction by establishing a feedback loop guided by social interaction. Architecture thus......-organizing, communicative environments for an organized complexity between flows of local interactions and network behaviour. The chapter applies the concepts on the case of the Pavilion Project, NoRA, built for the 10th International Architecture Biennale in Venice for the network of Food College Denmark....

  10. Urban water trajectories

    CERN Document Server

    Allen, Adriana; Hofmann, Pascale; Teh, Tse-Hui

    2017-01-01

    Water is an essential element in the future of cities. It shapes cities’ locations, form, ecology, prosperity and health. The changing nature of urbanisation, climate change, water scarcity, environmental values, globalisation and social justice mean that the models of provision of water services and infrastructure that have dominated for the past two centuries are increasingly infeasible. Conventional arrangements for understanding and managing water in cities are being subverted by a range of natural, technological, political, economic and social changes. The prognosis for water in cities remains unclear, and multiple visions and discourses are emerging to fill the space left by the certainty of nineteenth century urban water planning and engineering. This book documents a sample of those different trajectories, in terms of water transformations, option, services and politics. Water is a key element shaping urban form, economies and lifestyles, part of the ongoing transformation of cities. Cities are face...

  11. Urban mining systems

    CERN Document Server

    Nakamura, Takashi

    2015-01-01

    This book focuses on the fundamental concept of and current endeavors in “urban mining” among those who are interested in both metal resources and ecology. Systems for recycling and reusing precious metals and rare-earth minerals contained in used and discarded electronics are introduced in this book. The target audience is not academic researchers in the resource management and ecology fields but, rather, citizens who are concerned about our future environment and want to do something for the future.

  12. Urban Scaling in Europe

    Science.gov (United States)

    2016-03-16

    the structural funds for regional development and cohesion . Until recently, several systems of territorial units have coexisted in European...for European MAs versus population. See text and figures 1–7, electronic supplementary material, figures S1–S8 for additional details and electronic...scale as expected, although with wide confidence intervals (table 1). The urbanized area of Spanish cities appears superlinear, contrary to theory

  13. Austin's Urban Forest, 2014

    Science.gov (United States)

    David J. Nowak; Allison R. Bodine; Robert E. Hoehn; Christopher B. Edgar; Dudley R. Hartel; Tonya W. Lister; Thomas J. Brandeis

    2016-01-01

    An analysis of the urban forest in Austin, Texas, reveals that this area has an estimated 33.8 million trees with tree canopy that covers 30.8 percent of the city. The most common tree species are Ashe juniper, cedar elm, live oak, sugarberry, and Texas persimmon. Trees in Austin currently store about 1.9 million tons of carbon (7.0 million tons of carbon dioxide [CO...

  14. Urban Heat Islands

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.; Estes, Maury G.

    2011-01-01

    It is estimated that by the year 2025, 80% of the world's population will live in cities. This conversion of the natural landscape vegetation into man-made urban structures such as roads and buildings drastically alter the regional surface energy budgets, hydrology, precipitation patterns, and meteorology. Research studies from many cities have documented these effects range from decreases in air quality, increased energy consumption and alteration of regional climate to direct effects on human health.

  15. Cleanly: trashducation urban system

    DEFF Research Database (Denmark)

    Reif, Inbal; Alt, Florian; Ramos, Juan David Hincapie

    Half the world's population is expected to live in urban areas by 2020. The high human density and changes in peoples' consumption habits result in an ever-increasing amount of trash that must be handled by governing bodies. Problems created by inefficient or dysfunctional cleaning services are e......, which not only motivates our research but also provides useful information on reasons and possible solutions for trash problems....

  16. Urban micro-grids

    International Nuclear Information System (INIS)

    Faure, Maeva; Salmon, Martin; El Fadili, Safae; Payen, Luc; Kerlero, Guillaume; Banner, Arnaud; Ehinger, Andreas; Illouz, Sebastien; Picot, Roland; Jolivet, Veronique; Michon Savarit, Jeanne; Strang, Karl Axel

    2017-02-01

    ENEA Consulting published the results of a study on urban micro-grids conducted in partnership with the Group ADP, the Group Caisse des Depots, ENEDIS, Omexom, Total and the Tuck Foundation. This study offers a vision of the definition of an urban micro-grid, the value brought by a micro-grid in different contexts based on real case studies, and the upcoming challenges that micro-grid stakeholders will face (regulation, business models, technology). The electric production and distribution system, as the backbone of an increasingly urbanized and energy dependent society, is urged to shift towards a more resilient, efficient and environment-friendly infrastructure. Decentralisation of electricity production into densely populated areas is a promising opportunity to achieve this transition. A micro-grid enhances local production through clustering electricity producers and consumers within a delimited electricity network; it has the ability to disconnect from the main grid for a limited period of time, offering an energy security service to its customers during grid outages for example. However: The islanding capability is an inherent feature of the micro-grid concept that leads to a significant premium on electricity cost, especially in a system highly reliant on intermittent electricity production. In this case, a smart grid, with local energy production and no islanding capability, can be customized to meet relevant sustainability and cost savings goals at lower costs For industrials, urban micro-grids can be economically profitable in presence of high share of reliable energy production and thermal energy demand micro-grids face strong regulatory challenges that should be overcome for further development Whether islanding is or is not implemented into the system, end-user demand for a greener, more local, cheaper and more reliable energy, as well as additional services to the grid, are strong drivers for local production and consumption. In some specific cases

  17. Beyond urban penalty and urban sprawl: back to living conditions as the focus of urban health.

    Science.gov (United States)

    Freudenberg, Nicholas; Galea, Sandro; Vlahov, David

    2005-02-01

    Researchers have long studied urban health, both to describe the consequences of urban living and to design interventions to promote the health of people living in cities. Two approaches to understanding the impact of cities on health have been dominant, namely, urban health penalty and urban sprawl. The urban penalty approach posits that cities concentrate poor people and expose them to unhealthy physical and social environments. Urban sprawl focuses on the adverse health and environmental effects of urban growth into outlying areas. We propose a model that integrates these approaches and emphasizes urban living conditions as the primary determinant of health. The aim of the model is to move beyond describing the health-related characteristics of various urban populations towards identifying opportunities for intervention. Such a shift in framework enables meaningful comparisons that can inform public health activities at the appropriate level and evaluate their effectiveness in improving the health of urban populations. The model is illustrated with two examples from current urban public health practice.

  18. Sustainable Urban Transport Planning

    Directory of Open Access Journals (Sweden)

    Boitor Melania R.

    2013-07-01

    Full Text Available Environmental protection has become a common issue in every area, but extremely important for the domains which deal with intensive energy consumption as it is the case of the transportation. Achieving the sustainable cities on the other hand, is also focused on the protection of the environment in order to provide a higher quality of life for the population. Therefore it is considered that by improving the urban transportation planning additional benefits could be provided for both the environment and the sustainable development of the cities. One possibility is to supplement the traditionally land-use plans with the transportrelated zones analysis, where the city is divided in public transport, pedestrian and caroriented zones. Analyzing the transport-related zones of a city is important as it provides additional information in the assessment of the development trend. The process of zoning was conducted for the city of Cluj-Napoca, Romania. In this paper, the outcome of the zoning was analyzed for a more comprehensive review of the urban transport in order to attain a sustainable-oriented approach of the urban area development.

  19. Aquaponics in Urban Agriculture: Social Acceptance and Urban Food Planning

    OpenAIRE

    Georgia Pollard; James D. Ward; Barbara Koth

    2017-01-01

    Aquaponics is emerging as a novel technology with particular potential for urban agriculture (UA). The social acceptance of aquaponics and its place in urban food planning has not previously been studied. This study used focus groups, key informant interviews, and scenario analyses to investigate the reactions of Adelaide’s urban food opinion leaders and local government area (LGA) officials to aquaponics. Most of the focus group participants were unfamiliar with aquaponics. The perceived neg...

  20. Urban sustainable development from public participation in urban management

    OpenAIRE

    L. Karimifard

    2016-01-01

    Urban management in any context has a different economic, social and political structure, which is in harmony with the existing models of organization. In spite of these differences, in order to reach a sustainable urban development, several different conferences should be referred to. In the “Brundtland Commission 1987” about urban sustainable development these definitions have been given: “preservation and promotion of the quality level of city life. This consists of ecology, culture, polit...

  1. Rural-urban migration and urban unemployment in Nigeria.

    Science.gov (United States)

    Aigbokhan, B E

    1988-01-01

    This paper argues that urban unemployment in Nigeria has been due largely to a failure on the part of the government to pursue policies that reflect commitment on its part to its stated objectives, particularly with regard to employment opportunities. Rural-urban migration has been taking place in the country since the 1960s and at an increasing rate since the 1970s. Economic policies have contributed to this, notably the rural-urban imbalance resulting from the pattern of allocation of public investment expenditures and the wages determination process which tends to concentrate more on the urban sector. These have contributed to the widening urban-rural income differentials. In the face of such migration, the urban industrial sector has been able to absorb only a negligible proportion of migrants. A major factor that has contributed to this is the increased capital-intensity of the sector. Some laudable measures have been introduced this year, notably the establishment of the Directorate of Employment and the Directorate of Food, Road, and Rural infrastructure. The latter, if effectively implemented, should enhance rural income and thereby reduce the rural-urban income gap. The former should reduce the problem of open unemployment. While it is too early to assess the effects of these 2 measures on urban unemployment, they may not improve urban unemployment significantly. There is still the need to design policies to increase labor absorption in general.

  2. Challenges of urbanization and peri-urban development in Europe

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Nilsson, Kjell Svenne Bernhard

    2010-01-01

    Urbanisation has arguably been the most significant process of land use change in Europe since Second World War. Over 70% of Europe's population now lives in urban areas, which in turn, have grown in area by almost 80% over the last fifty years (EEA 2006). Urban areas cover approximately five...... percent of the territory of the European Union (EU25), and are growing more than twice as fast as the European population. A general consequence of the urbanisation trend and increasing wealth and mobility is urban sprawl, as well as the emergence of peri-urban areas....

  3. Urban structure, energy and planning

    DEFF Research Database (Denmark)

    Große, Juliane; Fertner, Christian; Groth, Niels Boje

    2016-01-01

    Transforming energy use in cities to address the threats of climate change and resource scarcity is a major challenge in urban development. This study takes stock of the state of energy in urban policy and planning and reveals potentials of and constraints to energy-efficient urban development....... The relationship between energy and urban structure provides a framework for discussing the role of urban planning to increase energy efficiency in cities by means of three in-depth case studies of medium-sized cities in Northern Europe: Eskilstuna in Sweden, Turku in Finland and Tartu in Estonia. In some ways...... these cities go ahead when it comes to their national climate and energy policies and aim to establish urban planning as an instrument to regulate and influence the city’s transition in a sustainable way. At the same time, the cities are constantly facing goal conflicts and limitations to their scope of action...

  4. Urban Green Infrastructure: German Experience

    OpenAIRE

    Diana Olegovna Dushkova; Sergey Nikolaevich Kirillov

    2016-01-01

    The paper presents a concept of urban green infrastructure and analyzes the features of its implementation in the urban development programmes of German cities. We analyzed the most shared articles devoted to the urban green infrastructure to see different approaches to definition of this term. It is based on materials of field research in the cities of Berlin and Leipzig in 2014-2015, international and national scientific publications. During the process of preparing the paper, consultations...

  5. Urban structure and air pollution

    Science.gov (United States)

    Lyons, T. J.; Kenworthy, J. R.; Newman, P. W. G.

    Representative driving cycles across the Perth, Western Australia, metropolitan region illustrate a direct relationship to urban land use. Movement away from the central business district results in fewer traffic events, higher speeds, longer cruise periods and shorter stops. The consequent reduction in root mean square acceleration leads to a corresponding reduction in vehicle emission factors. Urban planning implications are pursued and highlight the importance of public transport as an option in reducing urban air pollution.

  6. Hierarchical analysis of urban space

    OpenAIRE

    Kataeva, Y.

    2014-01-01

    Multi-level structure of urban space, multitude of subjects of its transformation, which follow asymmetric interests, multilevel system of institutions which regulate interaction in the "population business government -public organizations" system, determine the use of hierarchic approach to the analysis of urban space. The article observes theoretical justification of using this approach to study correlations and peculiarities of interaction in urban space as in an intricately organized syst...

  7. Computational Design of Urban Layouts

    KAUST Repository

    Wonka, Peter

    2015-10-07

    A fundamental challenge in computational design is to compute layouts by arranging a set of shapes. In this talk I will present recent urban modeling projects with applications in computer graphics, urban planning, and architecture. The talk will look at different scales of urban modeling (streets, floorplans, parcels). A common challenge in all these modeling problems are functional and aesthetic constraints that should be respected. The talk also highlights interesting links to geometry processing problems, such as field design and quad meshing.

  8. Governance of urban transitions: towards sustainable resource efficient urban infrastructures

    Science.gov (United States)

    Swilling, Mark; Hajer, Maarten

    2017-12-01

    The transition to sustainable resource efficient cities calls for new governance arrangements. The awareness that the doubling of the global urban population will result in unsustainable levels of demand for natural resources requires changes in the existing socio-technical systems. Domestic material consumption could go up from 40 billion tons in 2010, to 89 billion tons by 2050. While there are a number of socio-technical alternatives that could result in significant improvements in the resource efficiency of urban systems in developed and developing countries (specifically bus-rapid transit, district energy systems and green buildings), we need to rethink the urban governance arrangements to get to this alternative pathway. We note modes of urban governance have changed over the past century as economic and urban development paradigms have shifted at the national and global levels. This time round we identify cities as leading actors in the transition to more sustainable modes of production and consumption as articulated in the Sustainable Development Goals. This has resulted in a surge of urban experimentation across all world regions, both North and South. Building on this empirically observable trend we suggest this can also be seen as a building block of a new urban governance paradigm. An ‘entrepreneurial urban governance’ is proposed that envisages an active and goal-setting role for the state, but in ways that allows broader coalitions of urban ‘agents of change’ to emerge. This entrepreneurial urban governance fosters and promotes experimentation rather than suppressing the myriad of such initiatives across the globe, and connects to global city networks for systemic learning between cities. Experimentation needs to result in a contextually appropriate balance between economic, social, technological and sustainable development. A full and detailed elaboration of the arguments and sources for this article can be found in chapter 6 of Swilling M et

  9. Using Parametrics to Facilitate Collaborative Urban Design

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Benbih, Karima; Obeling, Esben

    2013-01-01

    in the context of the urban South which is characterized by high urban growth rates, weak planning systems and modest means. The current state of planning and urban development in Morocco is introduced as a context for discussing collaborative urban design and parametric urban design, and some tentative...

  10. Modeling urbanization patterns with generative adversarial networks

    OpenAIRE

    Albert, Adrian; Strano, Emanuele; Kaur, Jasleen; Gonzalez, Marta

    2018-01-01

    In this study we propose a new method to simulate hyper-realistic urban patterns using Generative Adversarial Networks trained with a global urban land-use inventory. We generated a synthetic urban "universe" that qualitatively reproduces the complex spatial organization observed in global urban patterns, while being able to quantitatively recover certain key high-level urban spatial metrics.

  11. Exploring Urban America: An Introductory Reader.

    Science.gov (United States)

    Caves, Roger W.

    This introductory text presents a collection of articles from urban-studies journals to introduce undergraduate students to the interdisciplinary field of urban studies. The book is divided into 9 parts as follows: Part 1: Cities and Urbanism; part 2: Urban History; part 3: Urban Policy; part 4: Economic Development; part 5: Community Services and…

  12. Thermal Characteristics of Urban Landscapes

    Science.gov (United States)

    Luvall, Jeffrey C.; Quattrochi, Dale A.

    1998-01-01

    Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., less than 15 m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for Huntsville, AL.

  13. Urban land planning in Serbia

    Directory of Open Access Journals (Sweden)

    Zeković Slavka L.

    2002-01-01

    Full Text Available In this paper, the capitalization, urban land management and planning routine have been explored. The focus dwells on the praxis and urban planning perspectives as a link and means for realizing the public interest in space and the role of 'urban transplants' as a lever of urban development. It has also been pointed to a certain discrimination of the property status and property rights through the category of 'public interest', which is articulated by way of urban planning. The unfairness of the existing planning system towards private property and 'taxation' of entrepreneurial activities is evident, especially in urban land use i.e. installing the height of the land rent. It is expected that urban planning is competent upon the background of societal democratization, privatization and introduction of market institutions where the perspectives shift towards democratic transformation, the regulatory role and protection of property rights and different actors’ interests in using urban land. The conclusion is that changes in the management of urban land are required with recommendations to consider public-private sector partnerships.

  14. Solos urbanos Urban soils

    Directory of Open Access Journals (Sweden)

    Fabrício de Araújo Pedron

    2004-10-01

    Full Text Available A forte pressão provocada pela expansão urbana desordenada sobre os recursos naturais, principalmente os solos, tem provocado danos, muitas vezes de difícil reparo. A grande concentração populacional em centros urbanos cada vez maiores tem dirigido a atenção de diferentes profissionais para o recurso solo, no sentido de entender sua dinâmica para minimizar sua degradação. No entanto, a falta de conhecimento sobre as propriedades, bem como sobre a aptidão dos solos sob uso urbano tem provocado o seu mau uso, resultando em processos como compactação, erosão, deslizamentos e inundações, assim como poluição com substâncias orgânicas, inorgânicas e patógenos, aumentando os custos do desenvolvimento afetando toda a sociedade. Neste sentido, este texto discute como o conhecimento pedológico pode diminuir os efeitos negativos provocados pelo processo de urbanização.The strong pressure caused by the disordered urban expansion over the natural resources, mainly the soils, has caused damages, many times difficult to repair. The great population concentration in urban centers getting larger and larger has been driving the attention of different professionals to soil resource, in the sense of understanding its dynamics to minimize its degradation. The lack of knowledge related to the soils properties and capability promote their inappropriate use, resultig in degrading processes as compaction, erosion, sliding, floods, and organic, inorganic and patogenic pollution, increasing the cost of development and affecting the whole society. This text discusses how pedologic knowledge can reduce the negative effects caused by the urbanization process.

  15. Renewed Urban Waterfront: Spatial Conditions of a Contemporary Urban Space Typology

    OpenAIRE

    Beate Niemann; Fabian Pramel

    2017-01-01

    The formerly industrially or militarily used Urban Waterfront is a potential area for urban development. Extensive interventions in the urban space come along with the development of these previously inaccessible areas in the city. The development of the Urban Waterfront in the European City is not subject to any recognizable urban paradigm. In this study, the development of the Urban Waterfront as a new urban space typology is analyzed by case studies of Urban Waterfront developments in Euro...

  16. Urban Songlines as Mediator

    DEFF Research Database (Denmark)

    Corlin, Anne

    2016-01-01

    The aim of this paper is to present an investigation of the method The Urban Songlines Book and how it works as a mediator for mapping the experienced space. The method contains a combination of aerial maps, photographs, and interviews as a way to understand the respondent´s use, relations...... and experiences of their neighborhood and the city. Through a presentation of the origin of the method, a description of the conducted study, and an analysis of the process in relation to theories about participatory design, social design, ANT and architectural sociology, the paper reveals how this method...

  17. Urban transportation projects conceptualised:

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

    is straightforward: transportation projects transform cities. The paradoxical reality thus is that a problem that has been traditionally conceptualized in technical terms (transportation engineering, transportation economics, planning theory, traffic engineering, urban planning, etc.), has tremendous consequences...... operation when discussing transportation projects in big cities. The tradition of Science and Technology Studies might have provided some clues. In the following paper we discuss the most prominent aspects of some theories in STS in order to understand and conceptualize the cases of Bogotá and Copenhagen...

  18. Urban runoff - Swedish experience

    International Nuclear Information System (INIS)

    Falk, Jan

    1987-01-01

    During the past 20 years hard effort has been devoted to the protection of rivers, lakes and the sea from pollution. This effort has mainly been focused on the obvious sources of pollution i.e. the concentrated outlet of sewage. Currently 75% of the urban population is served by advanced treatment plants. Not until recently attention was paid to sewerage. The official policy was that separate storm sewers was the only acceptable system and discharge permits generally required separation of existing combined sewers were to be abandoned there was little concern about overflows

  19. Sustainable urban growth

    International Nuclear Information System (INIS)

    Giraud, Pierre-Noel

    2011-01-01

    The principal messages from Energy and urban innovation are presented. This report by the World Energy Council has examined the challenges related to energy in big cities (in particular 'mega-cities'), the policies that are being or could be implemented, and the role of firms in this implementation. Considerable progress can be made by using existing techniques. The main difficulty has to do with diffusing them. There is a need for organizational and institutional innovations that will stimulate players, coordinate their actions and speed up the tempo of change

  20. Sanctuaries of urban sociability

    DEFF Research Database (Denmark)

    Greve, Anni

    of the national power elite. The second part of the paper has its focus upon religious sanctuaries of the utopian early phase of modernism, more precisely Edo-Tokyo during the Tokugawa era (1600-1863). Today, it is acknowledged that citizens of post industrial societies attach themselves to religions in response...... to, and in conditions of, social change and unrest. We see a revival of religions in modern urban societies, or the birth of ‘The Post Secular City’ (Beaumont 2008). Less attention has been paid to similar mechanisms in the era of early modernism. The paper points to ways by which religious...