bluuebunny/crossref_metadata_2025 huggingface dataset:
Community‐based participatory nursing research: A culturally focused case study
Authors: BOMAR Perri J.
Published: May 2010

This article provides highlights of a lecture, titled Community‐based Participatory Research: A Culturally Focused Case Study, given at the Japan Academy of Nursing Science's 29th annual meeting in Chiba, Japan on 28 November 2009. Community‐based participatory research (CBPR) is defined as research that includes both the researcher and the participant group in collaborative, egalitarian, and partnership processes to assess, define, problem‐solve, evaluate, and disseminate an issue that is chosen by the stakeholders. A CBPR framework is highlighted and case‐study examples from each stage are included. The barriers and facilitators for communities and researchers taking part in CBPR projects are described. Strategies to improve researcher competence in CBPR are listed. Community‐based participatory research can be very fulfilling when incorporated into a faculty member's teaching, research, and service to the community.
Explaining the Great American Crime Decline: A Review of Blumstein and Wallman, Goldberger and Rosenfeld, and Zimring
Authors: Barker Vanessa
Published: May 2010

This essay reviews three books as they document and explain the 1990s crime decline: Alfred Blumstein and Joel Wallman, eds., (2006)The Crime Drop in America; Arthur S. Goldberger and Richard Rosenfeld, eds., (2008)Understanding Crime Patterns: Workshop Report; and Franklin E. Zimring (2007),The Great American Crime Decline.

It presents the empirical detail of the crime decline and examines the most commonly cited explanatory factors: imprisonment, policing, demography, and economic growth. It then suggests alternative lines of research in urban sociology—urban development, youth culture, and immigration—that may better explain the decline as the result of changes in the cultural and social fabric of American society, particularly in cities where the steepest declines occurred.
The impact of extensive planting ofMiscanthusas an energy crop on future CO2atmospheric concentrations
Authors: HUGHES J. K. , LLOYD A. J. , HUNTINGFORD C. , FINCH J. W. , HARDING R. J.
Published: May 2010

A process‐based model of the energy cropMiscanthus×giganteusis integrated into the global climate impact model IMOGEN, simulating the potential of large‐scaleMiscanthusplantation to offset fossil fuel emissions during the 21st century. This simulation produces spatially explicit, annual projections ofMiscanthusyields from the present day to the year 2100 under an SRES A2 anthropogenic emissions scenario and includes the effects of climate change. IMOGEN also simulates natural vegetation and soil carbon storage throughout the 21st century. The benefit ofMiscanthuscultivation (avoiding fossil fuel emissions of CO2) is then compared with the cost of displacing natural vegetation (carbon emissions from vegetation and soil). The time taken for these effects to cancel out, the pay‐back time, is calculated regionally. The effects of large‐scaleMiscanthusplantation are then integrated globally to produce an estimate of atmospheric CO2concentrations throughout the 21st century. Our best estimate of the pay‐back time forMiscanthusplantation is 30 years. We project a maximum possible reduction in atmospheric CO2of 323 ppmv by the end of 21st century, with a reduction of 162 ppmv corresponding to the best estimate scenario.
Biomass production and energy balance of a 12‐year‐old short‐rotation coppice poplar stand under different cutting cycles
Authors: NASSI O DI NASSO N. , GUIDI W. , RAGAGLINI G. , TOZZINI C. , BONARI E.
Published: May 2010

Given today's political targets, energy production from agricultural areas is likely to increase and therefore needs to be more sustainable. The aim of this study was thus to carry out a long‐term field trial based on the poplar short‐rotation coppice (SRC), in order to compare dry matter, energy‐use efficiency and the net energy yield obtainable from this crop in relation to different harvest frequencies (1‐, 2‐ and 3‐year cutting cycles). The results showed that poplar SRC performed very well under temperate climates as it can survive up to 12 years, providing a considerable annual biomass yield (9.9, 13.8, 16.4 t ha−1 yr−1 for annual T1, biannual T2 and triennial T3 cutting cycles, respectively). The system tested in southern Europe showed a positive energy balance characterized by a high energy efficiency. We found that the choice of harvest interval had huge consequences in terms of energy yields. In fact, the energy efficiency improved from T1 to T2 and T3, while the net energy yield increased from 172 to 299 GJ ha−1 yr−1. This study suggests that, with 3‐year harvest cycles, poplar SRC can contribute to agronomic and environmental sustainability not only in terms of its high yield and energy efficiency but also in terms of its positive influence on limiting soil tillage and on the environment, given its low pesticide and nutrient requirements.
A Nonlinear Van Der Waals Force Model for Multiwalled Carbon Nanotubes Modeled by a Nested System of Cylindrical Shells
Authors: He X. Q. , Kitipornchai S. , Wang C. M. , Xiang Y. , Zhou Q.
Published: May 2010

In this paper, a more refined pressure distribution expression is derived to describe the van der Waals (vdW) interaction between any two tubes of a multiwalled carbon nanotube (MWCNT). Based on this new vdW force expression, a continuum cylindrical shell model is established for the buckling and post-buckling analysis of MWCNTs. The buckling and post-buckling responses are simulated for MWCNTs with various sizes to examine the consequences of ignoring the nonlinear term in the Taylor expansion of vdW force function. By comparing the results furnished by the commonly used linear vdW force model and the present nonlinear vdW force model, it is found that the buckling responses before the critical buckling strain are almost the same. Thus, the simple linear vdW force model suffices for the calculation of buckling loads. However, the post-buckling responses simulated from present nonlinear vdW force model are significantly lower than those given by the linear vdW force model. This indicates that the present nonlinear vdW force model must be used when considering the post-buckling responses.
Distribution of Eggs by Depth and Vegetation Type in Pacific Herring (Clupea harengus pallasi) Spawnings in Southern British Columbia
Authors: Haegele C. W. , Humphreys R. D. , Hourston A. S.
Published: May 2010

Pacific herring (Clupea harengus pallasi) spawn in southern British Columbia was surveyed by divers in 1976 and 1978. These surveys showed that the distribution of eggs is dependent on the type of vegetation on which the eggs are laid and on the slope of the beach. Most of the spawn on pure sea grass beds was deposited in the littoral zone. Spawn on mixtures of vegetation types was mostly sublittoral and the areal extent of these spawnings has been underestimated by surface surveys. To obtain a good estimate of egg deposition, diver surveys are required. Red algae were the major vegetation type for the study area, followed by sea grass, rockweed, kelp, and other brown algae. Eggs were deposited deeper as the beach slope became steeper. A small fraction of the total egg complement becomes exposed to air as a result of normal tidal cycles during the incubation period, and egg loss from predation and storms was estimated at 10%.Key words: Pacific herring, spawn, egg distribution, vegetation, depth, beach slope
Acute Toxicity of Nitrite to Rainbow Trout (Salmo gairdneri): Effects of pH, Nitrite Species, and Anion Species
Authors: Russo Rosemarie C. , Thurston Robert V. , Emerson Kenneth
Published: May 2010

The toxicity of nitrite to rainbow trout is pH-dependent within the range considered acceptable to most freshwater aquatic life (pH 6.5–9.0). Both of the nitrite species, NO2− and HNO2, are toxic. It is recommended that nitrite criteria to protect freshwater aquatic life be based on total nitrite, and that such criteria reflect the pH dependence of nitrite toxicity. Variation in the toxicity of nitrite in the presence of chloride, sulfate, phosphate, and nitrate anions has also been demonstrated. It is concluded that the toxicity of nitrite to fishes, in addition to being pH-dependent, is also dependent in varying degrees upon many of the anions that are commonly found in natural aquatic environments.Key words: nitrite, pH, chloride, phosphate, sulfate, toxicity, rainbow trout, Salmo gairdneri
Prediction of Total Phosphorus Concentrations, Chlorophyll a, and Secchi Depths in Natural and Artificial Lakes
Authors: Canfield Jr. Daniel E. , Bachmann Roger W.
Published: May 2010

A model for the prediction of total phosphorus was developed and tested using data on 704 nautral and artificial lakes including 626 lakes in the U.S. Environmental Protection Agency (EPA) National Eutrophication Survey. A statistical analysis showed that the best estimate for the sedimentation coefficient (σ) in the Vollenweider equation was[Formula: see text]for artificial lakes where L is the areal phosphorus loading rate (mg∙m−2∙yr−1) and z is the mean depth (m). The model yields unbiased estimates of phosphorus concentrations over a wide range of lake types and has a 95% confidence interval of 31–288% of the calculated total phosphorus concentration. Other models are less precise. Though total phosphorus concentrations can be predicted equally well in natural and artificial lakes, predictions of algal densities and water transparency are less reliable in artificial lakes, as the phosphorus–chlorophyll and chlorophyll–Secchi depth relationships are less precise. This seems to be due to the influence of nonalgal particulate materials.Key words: phosphorus models, eutrophication, lake trophic state
Distribution of Zooplankton Populations Within and Adjacent to a Thermal Plume
Authors: Evans Marlene S.
Published: May 2010

Zooplankton distributions in the 1-m stratum differed between ambient waters and the thermal plume of the Donald C. Cook Nuclear Power Plant. Zooplankton were most abundant in the warmest waters of the plume with the region of high densities extending over an approximate area of 0.2 to 0.3 km2. Water temperature was not a reliable indicator of alterations in zooplankton populations. Alterations were primarily due to upward vertical displacement of deep-living zooplankton. Large horizontal variability in zooplankton densities and use of conventional sampling procedures (vertically hauled nets, widely spaced stations) prevent traditionally designed monitoring programs from detecting such alterations. Zooplankton may experience indirect mortality losses in the plume if transfer of deep-living zooplankton to the surface layers makes them more visible to visual-feeding fish predators, and turbulences in the plume reduce zooplankters' ability to detect and avoid such predators.Key words: zooplankton, thermal plume, planktivorous fish, predation
Empirical Relationships Between Phytoplankton and Zooplankton Biomass in Lakes
Authors: McCauley Edward , Kalff Jaap
Published: May 2010

Empirical models based on regression analysis were derived using published values of phytoplankton and crustacean zooplankton biomass from lakes. Equations presented predict crustacean zooplankton biomass from measures of phytoplankton biomass. Zooplankton biomass was shown to be positively related to phytoplankton biomass based on an inter-lake comparison. Analyses of functional regression equations suggest that the ratio of zooplankton to phytoplankton biomass decreases as phytoplankton biomass increases among lakes. It is hypothesized that variation in the biomass of nannoplankton, representing the principal food source for crustaceans present in the phytoplankton community, can account for the variation in the biomass of the crustacean zooplankton community.Key words: phytoplankton, zooplankton, biomass, nannoplankton
Extraction of Living Meiofauna from Marine Sediments by Centrifugation in a Silica Sol—Sorbitol Mixture
Authors: Schwinghamer Peter
Published: May 2010

A simple, rapid method is described for the extraction of living marine organisms from sandy and muddy sediments using centrifugation in a buffered mixture of sorbitol and the silica sol Percoll. The method is suitable for the collection of delicate species of "soft" meiofauna. Combined with the use of an inverted plankton microscope and settling chambers, this method greatly reduces the time and labor spent in extracting and identifying meiobenthic organisms and benthic microalgae.Key words: meiofauna, Percoll, extraction
Reduced Survival and Fitness in Native Bivalves in Response to Fouling by the Introduced Zebra Mussel (Dreissena polymorpha) in Western Lake Erie
Authors: Haag Wendell R. , Berg David J. , Garton David W. , Farris Jerry L.
Published: May 2010

Fouling by the recently established zebra mussel (Dreissena polymorpha) causes differential effects among bivalve communities. In 3-mo experiments and surveys conducted in western Lake Erie during 1990, two native bivalves, Lampsilis radiata and Amblema plicata, showed consistent differences in mortality and biochemical indices of fitness in response to fouling by D. polymorpha. Lampsilis radiata was very sensitive to fouling, experiencing high mortality and reduced fitness in experiments and natural populations. In field experiments, female L. radiata suffered higher mortality and lower fitness than males. Amblema plicata was less sensitive to fouling; fitness was reduced in experimentally fouled A. plicata, but mortality and fitness in natural populations were not affected by D. polymorpha. Six species of native bivalves showed marked differences in mortality rates at three sites surveyed in western Lake Erie. Mortality was higher in the subfamilies Anodontinae and Lampsilinae (including L. radiata) than in Ambleminae (including A. plicata) at all three sites, suggesting that differences in life history strategy and shell morphology among subfamilies may be responsible for differential responses to fouling. These data suggest that fouling by D. polymorpha will result in profound changes in native bivalve community structure.
Application of Empirical Size-Dependent Models of Larval Fish Vital Rates to the Study of Production: Accuracy and Association with Adult Stock Dynamics in a Comparison among Species
Authors: Pepin Pierre
Published: May 2010

A simple model of the size-dependent change in biomass of a cohort of fish larvae based on empirically derived relationships for growth and mortality is presented. Model predictions are compared with data for seven species of larval fish sampled on the Grand Banks of Newfoundland in 1980–81 to determine (1) whether the slope of the size-dependent larval biomass curve is significantly different from the general empirical model, and (2) whether the slope and intercept of the biomass curve are reflective of relative year-class strength and stock abundance, respectively. The slope of the size-dependent larval biomass curve is not significantly different from that predicted by the model in six of seven cases. The slope of the larval biomass curve is not significantly correlated with standardized year-class strength. The height of the curve (i.e. intercept) is only weakly associated with adult stock biomass. I conclude from this set of observations that estimates of larval fish vital rates may not be measured with sufficient accuracy to permit detection of a significant association between deviations from the general empirical model and the factors that may influence survivorship during the larval phase in a comparison across species.
Production of Fish Populations in Lakes
Authors: Downing John A. , Plante Céline
Published: May 2010

Biological production estimates of 100 fish populations from 38 lakes worldwide were gathered from the literature. The relationship between the annual production of fish populations (P, kilograms per hectare per year), annual mean standing biomass (B, kilograms per hectare), and maximum individual body mass (W, grams) was approximately log10P = 0.32 + 0.94 log10B − 0.17 log10W (R2 = 0.84). This relationship is similar to one observed for lotic invertebrate populations and shows that P declines with W. Major axis regression indicated that the P/B:W relationship had an exponent similar to that predicted by allometric theory. The residuals from this multivariate equation suggest that fish production is positively correlated with temperature, lake phosphorus concentration, chlorophyll a concentration, primary production, and with pH. The results suggest a general bottom-up control of lake ecosystem components. The morphoedaphic index is not a good predictor of the production of fish populations. Assuming that sustainable yield is about 10% of production, sustainable yield would be less than 15% of the standing biomass for the majority of fish populations analyzed. Exploited populations were found to be about 70% more productive, on average, than unexploited populations of the same standing biomass and body-mass.
pH Tolerance and Metal Toxicity in Populations of the Planktonic DiatomAsterionella: Influences of Synthetic and Natural Dissolved Organic Carbon
Authors: Gensemer Robert W. , Smith Ralph E. H. , Duthie Hamish C. , Schiff Sherry L.
Published: May 2010

Two clones of Asterionella ralfsii cf americana Körn. were more tolerant of acidic pH with respect to batch culture growth rate than their congener, A. formosa Hass. The relative inability of A. formosa to satisfy trace metal requirements at lower pH appeared to be a major factor in its reduced tolerance of acidic conditions. The pH tolerance of A. formosa, and at times A. ralfsii, also could be modified when grown in media containing different concentrations of artificial or natural forms of dissolved organic carbon (DOC). Mixed trace metal additions (Cu, Zn, Mn, Fe, and Al) further affected pH tolerance in A. ralfsii both by alleviating limitation and by inducing toxicity, depending on the nature and concentration of DOC. Overall, our results were consistent with pH classification schemes for both A. ralfsii and A. formosa as they are commonly used in paleolimnological pH reconstruction models. However, apparent pH classifications for both Asterionella species could be altered by changes in DOC-mediated trace metal bioavailability. Their assignment to a specific pH category or distribution thus may not represent an inherent biological property of that taxon, but may strongly depend on chemical conditions which often vary in humic lakes subject to acid deposition.
Interactions among Antioxidant Defenses in Liver of Rainbow Trout (Oncorhynchus mykiss) Exposed to Cadmium
Authors: Palace V. P. , Majewski H. S. , Klaverkamp J. F.
Published: May 2010

Rainbow trout (Oncorhynchus mykiss) (mean weight 180 ± 10 g) fed diets deficient in ascorbic acid, tocopherol, both, or neither were exposed to one of three cadmium concentrations (0, 2, or 4 μg Cd/L). After 181 d of exposure, liver and whole blood were sampled. Cadmium exposure was found to significantly increase the Cd content in liver, especially in fish fed a diet deficient in ascorbic acid. Hepatic stores of ascorbic acid decreased in fish exposed to Cd and in fish fed diets deficient in tocopherol and ascorbic acid. Depletion of tocopherol in liver occurred only in those fish fed a diet deficient in tocopherol and exposed to Cd. Superoxide dismutase activity in liver increased with Cd exposure and with dietary deficiencies of tocopherol and ascorbic acid, while catalase was inhibited by exposure to Cd alone. Glutathione peroxidase activity was unaffected by Cd but was lower in fish fed a diet deficient in both tocopherol and ascorbic acid. Erythrocyte fragility, measured by spontaneous hemolysis of red blood cells in physiological saline, was increased by Cd exposure and the deficiencies of dietary tocopherol and ascorbic acid.
Relationships between Prey Concentration and Growth, Condition, and Mortality of Pacific herring, Clupea pallasi, Larvae in an Alaskan Subarctic Embayment
Authors: McGurk M. D. , Paul A. J. , Coyle K. O. , Ziemann D. A. , Haldorson L. J.
Published: May 2010

We tested the hypothesis that growth, condition, and mortality of four "trace" cohorts of Pacific herring, Clupea pallasi, larvae in Auke Bay, Alaska, in 1988 were limited by concentration of prey. Hatching of herring larvae coincided with the spring maximum of copepod nauplii production, so prey concentration was high enough to support successful feeding and growth. However, growth and condition differed significantly among cohorts. Low growth and condition were not caused by density-dependent competition for food among herring larvae because larvae were too dilute to affect prey concentration and were unlikely to be caused by competition within the entire plankton community because there is no evidence that nonherring plankters interfered with feeding of herring larvae. Most larvae with low condition were from two cohorts that hatched from the upper zone, which suggests that desiccation and extremes of temperature may have disrupted embryonic development and produced larvae that were not competent to feed successfully. There were no among-cohort differences in instantaneous mortality. We conclude that growth, condition, and mortality of herring larvae in Auke Bay in 1988 were not limited by food, but by other factors such as predation and environmental conditions during egg incubation.
Comparing Dynamic Versions of the Schaefer and Fox Production Models and Their Application to Lobster Fisheries
Authors: Yoshimoto Stacey S. , Clarke Raymond P.
Published: May 2010

Dynamic approaches (integrated and finite difference) to the Schaefer and Fox production models are applied to four commercial lobster fisheries. The integrated versions provided better predictions than their finite difference counterparts. Only the integrated version of the Fox model provides realistic (positive) biological parameter estimates for all four fisheries, and bootstrapping reveals those estimates to be generally stable. Additionally, this model performs well when applied to data where certain assumptions of surplus production modeling are fulfilled. The results suggest further investigation of the integration procedure.
Plankton and Chemical–Physical Development in Six Swedish West Coast Lakes under Acidic and Limed Conditions
Authors: Hörnström Einar , Ekström Christina , Fröberg Elisabeth , Ek Jörgen
Published: May 2010

Increases in pH from 4.5–5.3 to 7–7.6 after liming (1978–85) in six acidified lakes in the west coast area of Sweden caused increased concentration of humic compounds and decreased transparency compared with levels before liming. Concentrations of total P increased markedly whereas those of NO3-N decreased. The phytoplankton composition changed completely in all lakes shortly after liming, but a species richness similar to that in unacidified lakes was not reached until after 2–5 yr, and in the previously most acidified lakes, several species remained absent. The composition of the phytoplankton indicated increased primary production. The volumetric dominance within the zooplankton shifted generally from Eudiaptomus–Holopedium to Cyclops–Daphnia. The occurrence of Rotatoria and Cladocera species increased and the composition became similar to that in unacidified lakes 2–5 yr after liming. The biotic development is largely explained by chemical–physical changes such as increased pH, reduced Al concentration, increased P concentration, and increased organic content, particularly humus.
Density-Dependent Geographic Distribution of Atlantic Cod (Gadus morhua) in the Southern Gulf of St. Lawrence
Authors: Swain D. P. , Wade E. J.
Published: May 2010

We tested effects of population size on the geographic distribution of Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence for age groups 3–8+ over the period 1971–90. Distribution was density dependent for all six age groups. Geographic range or stock area increased with abundance for each age group. Variation in abundance explained 63–94% of the variation in stock area. During periods of low abundance, the highest cod densities occurred in western regions of the southern Gulf for all age groups. Geographic distribution during these periods was more restricted for younger cod than for older cod. Density of age-3 cod was relatively high in only one of three western regions whereas densities of older cod were relatively high in two or all of these regions. As abundance increased, density increased slowly in the regions where cod were concentrated at low population sizes and more rapidly in surrounding regions. The greatest densities were found in the same area at low and high levels of abundance for younger cod but in different areas at these two abundance levels for older cod. We discuss this variation in geographic distribution in terms of density-dependent habitat selection and note its implications for stock assessment.
Partial Recruitment Considerations in Setting Catch Quotas
Authors: Sinclair A. F.
Published: May 2010

An approach is presented for investigating the interactions between fishing fleets that compete by exploiting different age-groups of the same resource population. The term "partial recruitment" (PR) is used to describe the age-specific exploitation pattern experienced by a population, either from individual fishing fleets or the combined effects of several fleets. Methods are presented to calculate catch quotas for the individual fleets if the management objective is to keep fleet effort constant, or alternatively to predict catch rates by fleet if the allocation rules are based on a percentage sharing of the total allowable catch (TAC) among fleets. Simulations based on an Atlantic cod (Gadus morhua) fishery on the Nova Scotian Shelf is used to illustrate the method. The results indicate the importance of considering differences in PR among competing fishing fleets when setting catch quotas. The relative effort exerted by the fleets will affect target fishing mortalities. The fleet that concentrates on younger fish can intercept recruitment. Since the fleets exploit different age-groups, changes in fishable biomass due to recruitment variation are lagged, and fishing success will vary among fleets. Understanding the dynamics of PR may help explain why certain fleets either exceed or fall short of catch quotas.
Aggregating Behavior of Ovigerous Female Red King Crab, Paralithodes camtschaticus, in Auke Bay, Alaska
Authors: Stone Robert P. , O'Clair Charles E. , Shirley Thomas C.
Published: May 2010

Ovigerous female red king crab, Paralithodes camtschaticus, monitored with ultrasonic biotelemetry, displayed distinct seasonal shifts in habitat use and bathymetric distribution. Crab occupied deep water between June and mid-November, relatively shallow water between mid-November and early March, and returned to deeper water prior to molting and mating in spring. Females were nonrandomly distributed within both depth ranges but seasonally changed their behavior and degree of association with conspecifics. Tagged crab were more aggregated (lower mean nearest neighbor distances) in winter than in summer and fall (F-test, P < 0.01). Winter SCUBA observations supported these results; females of mixed age-classes formed dense aggregations in shallow water, and crab exhibited "podding" behavior similar to that reported for younger age-classes. Adult males were associated with aggregations during late winter and early spring. Observations from the manned submersible Delta indicated that females were nonrandomly distributed in the deepwater habitat as well and probably formed loosely knit feeding aggregations there. Seasonal changes in aggregation densities and benthic areas used were the same during the two consecutive years of this study.
Effects of Early Rearing Environment on Stress Response, Immune Function, and Disease Resistance in Juvenile Coho (Oncorhynchus kisutch) and Chinook Salmon (O.tshawytscha)
Authors: Salonius Kira , Iwama George K.
Published: May 2010

Coho (Oncorhynchus kisutch) and chinook salmon (0. tshawytscha) from aquaculture and wild environments were subjected to handling (30–60 s of netting and aerial emersion) and disease challenges. Plasma cortisol concentrations ([cortisol]pl) in both coho and chinook salmon from wild environments were significantly elevated 4 h after handling. Colonized coho salmon (hatchery-reared fish, transported into a natural water body as fry) responded in a similar fashion to wild fish, while those reared entirely in the hatchery showed no significant rise in [cortisol]pl. The responses to handling stress were retained in wild and colonized coho salmon after 7 mo of hatchery rearing. A transient increase in the leukocyte to red blood cell ratio in both wild and hatchery-reared chinook salmon occurred 4 h after handling. Handling signficantly decreased the antibody-producing cell (APC) number in wild fish and elevated their [cortisol]plrelative to hatchery fish. Wild fish had the highest APC number among the three groups before the handling. No difference in resistance to Vibrio anguillarum was apparent in coho and chinook salmon among the different rearing environments, although chinook salmon were generally more susceptible; disease resistance was reduced in wild coho salmon after 7 mo of rearing in a hatchery.
Variation in Colour of Pseudoterranova decipiens (Nematoda; Anisakidae) Larvae Correlates with Haemoglobin Concentration in the Pseudocoelomic Fluid
Authors: Dixon B. , Kimmins W. , Pohajdak B.
Published: May 2010

Larval sealworm (Pseudoterranova decipiens) were collected from the fillets of Atlantic cod (Gadhus morhua) and the relationship between the colour of the nematodes, which varied from reddish brown to white, and the concentration of haemoglobin in their pseudocoelomic fluid was investigated. The colour of the haemoglobin, which makes up greater than 30% of the protein in the pseudocoelomic fluid, is derived from the heme group. As the heme copurifies with the protein and does not exist in the free form, colour variations in the nematode may, therefore, be due to differences in haemoglobin content. We investigate the possible regulation of levels of this protein and discuss the mechanisms by which this regulation would be achieved.
Interactive Influence of Turbidity and Light on Larval Bluegill (Lepomis macrochirus) Foraging
Authors: Miner Jeffrey G. , Stein Roy A.
Published: May 2010

In a series of in situ enclosure experiments with larval bluegill (Lepomis macrochirus), we demonstrate that turbidity from suspended sediments reduces bluegill consumption of crustacean zooplankton, primarily cyclopoid copepods and copepod nauplii. However, this reduction occurred only when light intensity in parts of enclosures fell below a threshold, estimated at < 450 lx. Following recent studies demonstrating copepod diel vertical migration in response to predators, it appears that copepods in our experiments used low-light strata as a refuge. Without this apparent refuge present, larval bluegill consumption increased with increasing turbidity, but prey were smaller on average. Thus, prey biomass consumed by larval bluegill did not differ with turbidity in high-light conditions. We postulate that the shift to smaller prey across taxa at higher turbidity, when light intensity exceeded 450 lx, derives from increased prey–background contrast. In low-light conditions, larval bluegill consumed larger, but fewer, zooplankton with increasing turbidity, resulting in lower prey biomass consumed. Thus, we demonstrate the field conditions causing negative turbidity effects on larval fish foraging success, and thus growth and recruitment.
Major Ion Chemistry of Lakes on the Kenai Peninsula, Alaska
Authors: Eilers J. M. , Landers D. H , Newell A. D. , Mitch M. E. , Morrison M. , Ford J.
Published: May 2010

We characterized the major ion chemistry of over 800 lakes on the Kenai Peninsula, Alaska, from a probability sample of 59 lakes (August 1988). There were two groups: alkalinity < 300 μeq/L (78% of the lakes) and alkalinity > 700 μeq/L. Low-alkalinity lakes had significantly lower concentrations of base cations and silica and significantly higher average concentrations of dissolved organic carbon (DOC) than high-alkalinity lakes. Despite widespread acidic soils and bog vegetation, and resulting high DOC concentrations, none of the lakes sampled was acidic. Sulfate concentrations (~3 μeq/L) were similar in the two groups, as were Cl− concentrations, which decreased with distance from the coast. High-alkalinity lakes were similar chemically to rivers and shallow aquifers in the region, suggesting that the high alkalinity is a product of the major weathering reactions in this terrain; the substantially different ratios of base cations in the two groups also indicate quantitative and qualitative weathering differences. Low-alkalinity lakes were at higher elevations than high-alkalinity lakes, presumably in groundwater recharge zones. Consequently, the chemical differences between the two lake groups appeared to be controlled by relatively small differences in local hydrologic setting, and possibly by differences in mineralogy along the groundwater flowpaths.
Effects of Biotreated Bleached Kraft Mill Effluent on Fingerling Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Servizi J. A. , Gordon R.W. , Martens D. W. , Lockhart W. L. , Metner D. A. , Rogers I. H. , McBride J. R. , Norstrom R. J.
Published: May 2010

Fingerling chinook salmon (Oncorhynchus tshawytscha) were chronically exposed in the laboratory to nonlethal biologically treated bleached kraft mill effluent (TBKME) at concentrations and temperatures typical of the Fraser River. Laboratory exposure was for 144 d in freshwater followed by 66 d in seawater without TBKME. Exposed fish bioconcentrated chlorophenols, chloroguiacols, and extractable organochlorine substances in proportion to the aqueous concentrations of the substances. Polychlorinated dibenzo-p-dioxins (PCDD's) and polychlorinated dibenzofurans (PCDF's) were also bioaccumulated, but the low body burdens compared with wild fingerling chinook indicated that the laboratory environment did not account for biomagnification via the food chain. Growth, mortality, hematocrit, protein and fat content, liver somatic index, sorbitol dehydrogenase, and tolerance to hypoxia were not affected by TBKME exposure. Increased nuclear diameters of interrenal cells among TBKME-exposed fish indicated that these fish were experiencing chronic stress. Hepatic and renal granulomas of Bacterial Kidney Disease origin were observed in some TBKME-exposed fish, but there was only a tenuous link between TBKME exposure and disease resistance. Hepatic ethoxyresorufin-O-deethylase (EROD) activity was correlated with dioxin toxic equivalency (TEQ). From this analysis, we estimated a threshold for EROD induction between 0.3 and 1.0 ng TEQ∙kg−1.
MONETARY POLICY COOPERATION TO SUPPORT ASIAN ECONOMIC INTEGRATION
Authors: CHOW HWEE KWAN , KRIZ PETER NICHOLAS , MARIANO ROBERTO S. , TAN AUGUSTINE H. H.
Published: May 2010

This paper considers the form of monetary policy coordination and regional exchange rate arrangement that would best support economic and financial integration in East Asia. In view of the region's economic diversity, we propose a graduated program of informal policy cooperation from weak forms of cooperation to more intensive modes of cooperation such as the adoption of common monetary policy objectives. An array of informal monetary arrangements rooted to the degree of institutional development can improve the effectiveness of both sovereign and regional institutions, and promote integration in East Asia. Drawing upon the European experience with the Exchange Rate Mechanism (ERM), we conclude that East Asia should first embark on other forms of integration to aid in the development of a high degree of real and nominal convergence amongst the regional countries. Only then would an ERM-type system that employs a regional monetary unit become more sustainable and less susceptible to speculative currency attacks in the region.
IMPROVED LOWER BOUND FOR THE NUMBER OF KNOTTED HAMILTONIAN CYCLES IN SPATIAL EMBEDDINGS OF COMPLETE GRAPHS
Authors: HIRANO YOSHIYASU
Published: May 2010

We prove that every spatial embedding of the complete graph K8 contains at least 3 knotted Hamiltonian cycles, and that every spatial embedding of Kn contains at least 3(n - 1)(n - 2) ⋯ 8 knotted Hamiltonian cycles, for n > 8.
NOTIONS OF POSITIVITY AND THE OZSVÁTH–SZABÓ CONCORDANCE INVARIANT
Authors: HEDDEN MATTHEW
Published: May 2010

In this paper we examine the relationship between various types of positivity for knots and the concordance invariant τ discovered by Ozsváth and Szabó and independently by Rasmussen. The main result shows that, for fibered knots, τ characterizes strong quasipositivity. This is quantified by the statement that for K fibered, τ(K) = g(K) if and only if K is strongly quasipositive. A corollary is that any knot admitting a lens space surgery or, more generally, an L-space surgery, is strongly quasipositive. In addition, we survey existing results regarding τ and forms of positivity and highlight several consequences concerning the types of knots which are (strongly) (quasi) positive.
EXAMPLES OF REDUCIBLE AND FINITE DEHN FILLINGS
Authors: KANG SUNGMO
Published: May 2010

If a hyperbolic 3-manifold M admits a reducible and a finite Dehn filling, the distance between the filling slopes is known to be 1. This has been proved recently by Boyer, Gordon and Zhang. The first example of a manifold with two such fillings was given by Boyer and Zhang. In this paper, we give examples of hyperbolic manifolds admitting a reducible Dehn filling and a finite Dehn filling of every type: cyclic, dihedral, tetrahedral, octahedral and icosahedral.
TWIST LATTICES AND THE JONES–KAUFFMAN POLYNOMIAL FOR LONG VIRTUAL KNOTS
Authors: CHRISMAN MICAH W.
Published: May 2010

In this paper, we investigate twist sequences for Kauffman finite-type invariants and Goussarov–Polyak–Viro finite-type invariants. It is shown that one obtains a Kauffman or GPV type of degree ≤ n if and only if an invariant is a polynomial of degree ≤ n on every twist lattice of the right form. The main result of this paper is an application of this technique to the coefficients of the Jones–Kauffman polynomial. It is shown that the Kauffman finite-type invariants obtained from these coefficients are not GPV finite-type invariants of any degree by explicitly showing they can never be polynomials. This generalizes a result of Kauffman [8], where it is known for degree k = 2.
WHAT IS THE "DAMAGES FUNCTION" FOR GLOBAL WARMING — AND WHAT DIFFERENCE MIGHT IT MAKE?
Authors: WEITZMAN MARTIN L.
Published: May 2010

The existing literature on climate change offers little guidance on why one specification or another of a "damages function" has been selected. Ideally, one wants a functional form that captures reality adequately, yet is analytically sufficiently tractable to yield useful results. This paper gives two plausible risk aversion axioms that a reduced form utility function of temperature change and the capacity to produce consumption might reasonably be required to satisfy. These axioms indicate that the standard-practice multiplicative specification of disutility damages from global warming, as well as its additive analogue, are special cases of this paper's theoretically derived utility function. Empirically, the paper gives some numerical examples demonstrating the surprisingly strong implications for economic policy of the distinction between additive and multiplicative disutility damages.
THE ECONOMICS OF HURRICANES AND IMPLICATIONS OF GLOBAL WARMING
Authors: NORDHAUS WILLIAM D.
Published: May 2010

This study examines the economic impacts of US hurricanes. The major conclusions are the following: First, there are substantial vulnerabilities to intense hurricanes in the Atlantic coastal United States. Damages appear to rise with the ninth power of maximum wind speed. Second, greenhouse warming is likely to lead to stronger hurricanes, but the evidence on hurricane frequency is unclear. We estimate that the average annual US hurricane damages will increase by $10 billion at 2005 incomes (0.08 percent of GDP) due to global warming. However, this number may be underestimated by current storm models. Third, 2005 appears to have been a quadruple hurricane outlier, involving a record number of North Atlantic tropical cyclones, a large fraction of intense storms, a large fraction of the intense storms making landfall in the United States, and an intense storm hitting the most vulnerable high-value region in the country.
Breathing patterns during cardiac arrest
Authors: Haouzi Philippe , Ahmadpour Nasrollah , Bell Harold J. , Artman Stephen , Banchs Javier , Samii Soraya , Gonzalez Mario , Gleeson Kevin
Published: May 2010

The absence of respiratory movements is a major criterion recommended for use by bystanders for recognizing an out-of-hospital cardiac arrest (CA), as the persistence of eupneic breathing is considered to be incompatible with CA. The basis for CA-related apnea is, however, uncertain, since brain stem Po2is not expected to drop immediately to the critical level where anoxic apnea occurs. It is therefore essential on both clinical and physiological grounds to determine whether and when breathing stops after the onset of CA. In eight patients, we measured the ventilatory response at the onset of ventricular fibrillation (VF) for 12–15 s during the placement of an implantable cardioverter-defibrillator device. We found that regular eupneic breathing was maintained unchanged despite the cessation of systemic and pulmonary blood flow generated by the heart. We extended these findings in adult sheep and found that, as in humans, the normal ventilatory pattern persists unchanged for the first 15 s despite the drop in blood pressure, followed by a progressive increase in minute ventilation, which was sustained for up to 164 s. The ensuing apnea was disrupted by typical gasps occurring at a very slow frequency. These observations suggest a complete “decoupling” between the return of CO2to the pulmonary circulation and continued effective respiratory activity, contrary to what we predicted. This delayed cessation of eupneic breathing during the absence of cardiac pump function is likely related to the time needed for brain stem anoxia to develop. These findings challenge the notions that 1) ventilation stops as pulmonary blood flow/cardiac output ceases and 2) the presence of eupneic breathing is a reliable sign of effective cardiac pumping activity.
No effect of arm-crank exercise on diaphragmatic fatigue or ventilatory constraint in Paralympic athletes with cervical spinal cord injury
Authors: Taylor Bryan J. , West Christopher R. , Romer Lee M.
Published: May 2010

Cervical spinal cord injury (CSCI) results in a decrease in the capacity of the lungs and chest wall for pressure, volume, and airflow generation. We asked whether such impairments might increase the potential for exercise-induced diaphragmatic fatigue and mechanical ventilatory constraint in this population. Seven Paralympic wheelchair rugby players (mean ± SD peak oxygen uptake = 16.9 ± 4.9 ml·kg−1·min−1) with traumatic CSCI (C5–C7) performed arm-crank exercise to the limit of tolerance at 90% of their predetermined peak work rate. Diaphragm function was assessed before and 15 and 30 min after exercise by measuring the twitch transdiaphragmatic pressure (Pdi,tw) response to bilateral anterolateral magnetic stimulation of the phrenic nerves. Ventilatory constraint was assessed by measuring the tidal flow volume responses to exercise in relation to the maximal flow volume envelope. Pdi,twwas not different from baseline at any time after exercise (unpotentiated Pdi,tw= 19.3 ± 5.6 cmH2O at baseline, 19.8 ± 5.0 cmH2O at 15 min after exercise, and 19.4 ± 5.7 cmH2O at 30 min after exercise; P = 0.16). During exercise, there was a sudden, sustained rise in operating lung volumes and an eightfold increase in the work of breathing. However, only two subjects showed expiratory flow limitation, and there was substantial capacity to increase both flow and volume (<50% of maximal breathing reserve). In conclusion, highly trained athletes with CSCI do not develop exercise-induced diaphragmatic fatigue and rarely reach mechanical ventilatory constraint.
Left-to-right systolic ventricular interaction in patients undergoing biventricular stimulation for dilated cardiomyopathy
Authors: Osculati Giuseppe , Malfatto Gabriella , Chianca Roberto , Perego Giovanni B.
Published: May 2010

Left-to-right systolic ventricular interaction (i.e., the phenomenon by which the left ventricle contributes to most of the flow and to two-thirds of the pressure generated by the right ventricle) originates from transmission of systolic forces between the ventricles through the interventricular septum and from the mechanical effect of the common muscle fibers encircling their free walls. As a consequence, any reduction of left ventricular free wall function translates in lower right ventricular pressure or function. We investigated whether systolic ventricular interaction could be evidenced in nine patients with dilated cardiomyopathy in whom a biventricular pacemaker was implanted. Changes in right and left ventricular pressures were measured with high-fidelity catheters, before and after periods of biventricular pacing from the right atrium with different stimulation intervals to the right and left ventricles, respectively. The steady-state changes of left and right ventricular systolic pressure obtained from any single pacing interval combination were considered. We then calculated, with a two-level mixed regression analysis of the entire data set, the relation between changes in left and right systolic pressures: the presence of a statistically significant slope was assumed as evidence of ventricular interaction. The slope of the regression replaced the crude pressure ratio as an estimate of the gain of the interaction; its value compared with values observed in experimental studies. Moreover, its dependence on septal elastance and on right ventricular volume was similar to that already demonstrated for ventricular interaction gain. In conclusion, the linear relationship we found between systolic pressure changes in the two ventricles of patients with dilated cardiomyopathy during biventricular pacing could be explained in terms of ventricular interaction.
Onset of pulmonary ventilation in fetal sheep produces pial arteriolar constriction dependent on cytochrome p450 ω-hydroxylase activity
Authors: Ohata Hiroto , Gebremedhin Debebe , Narayanan Jayashree , Harder David R. , Koehler Raymond C.
Published: May 2010

With the onset of ventilation at birth, cerebral blood flow decreases as oxygenation increases, but the mechanism of cerebral vasoconstriction is unknown. Cytochrome P-450 ω-hydroxylase activity metabolizes arachidonic acid to 20-HETE, a potent vasoconstrictor, in a physiologically relevant O2-dependent manner. We tested the hypothesis that the ω-hydroxylase inhibitor, 17-octadecynoic acid (17-ODYA), reduces cerebral vasoconstriction during in utero ventilation with O2in fetal sheep. In anesthetized pregnant sheep near term, the fetal head was exposed with the rest of the body remaining in utero. Pial arteriolar diameter was measured by intravital microscopy through a closed cranial window superfused with vehicle or 17-ODYA. Mechanical ventilation of the fetal lungs with a high O2mixture to increase arterial Po2from ∼20 to ∼90 Torr markedly decreased pial arteriolar diameter by 24 ± 3% (±SE) without a change in arterial pressure. In contrast, superfusion of 17-ODYA completely blocked the decrease in diameter (2 ± 3%) with increased oxygenation. Vasoconstriction to hypocapnia was intact after returning to the baseline intrauterine oxygenation state, thereby indicating that the effect of 17-ODYA was selective for increased oxygenation. In cerebral arteries isolated from fetal sheep, increasing oxygenation increased 20-HETE production. We conclude that cytochrome P-450 ω-hydroxylase activity makes an important contribution to cerebral vasoconstriction associated with the onset of ventilation at birth.