bluuebunny/crossref_metadata_2025 huggingface dataset:
Views on data use, confidentiality and consent in a predictive screening involving children: Table 1
Authors: Helgesson G , Swartling U
Published: March 2008

Data from the 5–6 year control questionnaire of the ABIS study, a Swedish prospective screening of children for Type 1 diabetes, indicates a genuine trust in the researchers—very few participating families expressed concern about their participation. Nevertheless, a majority do not want their research data to be used beyond the agreement of the original consent. They want to be asked for renewed consent in such cases. A vast majority also want potential high-risk information about their child to be communicated to them. Most participating families want this regardless of whether any preventive treatment is available. Although potential benefits for their child is a motivation for participation for a majority of the respondents, they also claim to be motivated by altruistic reasons. These results are compared to results from two similar studies in the UK.
Paying for particulars in people-to-be: commercialisation, commodification and commensurability in human reproduction
Authors: Fox D
Published: March 2008

The push of biomedical profits and pull of consumer desire for greater happiness and superior performance heralds a robust market in offspring enhancement. There are two reasons we might worry about the reach of commerce into the realm of selective reproduction. The first concern is that for-profit genetic enhancement, under conditions of economic necessity, would exploit the poor, by coercing them, in effect, to part with reproductive material they would prefer not to sell for money, if not for their desperate situation. The second concern is that the market valuation and exchange of sperm, eggs, and embryos would distort the meaning, and degrade the worth, of those procreative goods. I argue that the concern about exploitation does not give reason to resist a market in pre-natal enhancement, but that the concern about degradation does. This degradation concern gives rise to two specific worries: one about altruism and another about commensurability. I conclude by sketching several policy recommendations to regulate the transfer of money in exchange for sperm and eggs with specified characteristics.
Duty to disclose what? Querying the putative obligation to return research results to participants
Authors: Miller F A , Christensen R , Giacomini M , Robert J S
Published: March 2008

Many research ethics guidelines now oblige researchers to offer research participants the results of research in which they participated. This practice is intended to uphold respect for persons and ensure that participants are not treated as mere means to an end. Yet some scholars have begun to question a generalised duty to disclose research results, highlighting the potential harms arising from disclosure and questioning the ethical justification for a duty to disclose, especially with respect to individual results. In support of this view, we argue that current rationales for a duty of disclosure do not form an adequate basis for an ethical imperative. We review policy guidance and scholarly commentary regarding the duty to communicate the results of biomedical, epidemiological and genetic research to research participants and show that there is wide variation in opinion regarding what should be disclosed and under what circumstance. Moreover, we argue that there is fundamental confusion about the notion of “research results,” specifically regarding three core concepts: the distinction between aggregate and individual results, amongst different types of research, and across different degrees of result veracity. Even where policy guidance and scholarly commentary have been most forceful in support of an ethical imperative to disclose research results, ambiguity regardingwhatis to be disclosed confounds ethical action.
Dentistry and the ethics of infection
Authors: Shaw D
Published: March 2008

Currently, any dentist in the UK who is HIV-seropositive must stop treating patients. This is despite the fact that hepatitis B-infected dentists with a low viral load can continue to practise, and the fact that HIV is 100 times less infectious than hepatitis B. Dentists are obliged to treat HIV-positive patients, but are obliged not to treat any patients if they themselves are HIV-positive. Furthermore, prospective dental students are now screened for hepatitis B and C and HIV, and are not allowed to enrol on Bachelor of Dental Surgery degrees if they are infectious carriers of these diseases.

This paper will argue that: (i) the current restriction on HIV-positive dentists is unethical, and unfair; (ii) dentists are more likely to contract HIV from patients than vice versa, and this is not reflected by the current system; (iii) the screening of dental students for HIV is also unethical; (iv) the fact that dentists can continue to practise despite hepatitis B infection, but infected prospective students are denied matriculation, is unethical; and (v) that the current Department of Health protocols, as well as being intrinsically unfair, have further unethical effects, such as the waste of valuable resources on ‘lookback’ exercises and the even more damaging loss of present and future dentists. Regulation in this area seems to have been driven by institutional fear of public fear of infection, rather than any scientific evidence or ethical reasoning.
The sorus of Polypodium virginianum: some aspects of the development and structure of paraphyses and sporangia
Authors: Peterson R. L. , Kott L. S.
Published: March 2008

A comparative study of the ontogeny of sporangia and paraphyses showed that these organs are homologous, with divergence in structure and function occurring after several divisions in the initials of these organs. Paraphyses develop an elongated stalk bearing several vesiculated cells, most of which bear appendages or glandular hairs. Sporangial initials form stalks that subtend the sporangium or spore case enclosing cells which undergo meiosis to form spores. The stalk and vesiculated cells of each paraphysis have a rather complex cytoplasm in the early stages of ontogeny, but ultimately these cells become vacuolated with large deposits of tannins. The tannin bodies originate in small cytoplasmic vacuoles which appear to fuse, forming larger vacuoles with tannin deposits. Stalk and annulus cells of the sporangia also form vacuoles with tannin inclusions. The appendages of the vesiculated cells remain cytoplasmic much longer than the subtending vesiculated cells, but eventually they vacuolate and form tannins as well. It is suggested that the paraphyses perform a protective function for the developing sorus to prevent the loss of water from the developing sporangia.
Studies on nuclear division in basidia of Poria latemarginata
Authors: Setliff E. C. , Hoch H. C. , Patton R. F.
Published: March 2008

Nuclear division in basidia of Poria latemarginata was studied comparatively by light and electron microscopy. Premeiotic mitosis occurred in the lower half of the basidium and was oriented parallel to the longitudinal axis of the basidium. Mitosis was not observed with the light microscope and only late anaphase figures of mitosis were seen with the electron microscope. Mitosis was intranuclear with microtubules oriented between two spindle pole bodies (SPBs). The SPBs were spherical with a central core of material slightly more electron opaque than the surrounding SPB material. The nuclear envelope remained intact except at the SPBs.Divisions I and II of meiosis were chiastobasidial and occurred at the apices of basidia. The major features of meiosis observed by both light and electron microscopy were (1) karyogamy followed by the presence of one or two nucleoli in the prophase nucleus; (2) elongated chromosomes and synapsis at late zygotene – pachytene; (3) occurrence of a spindle at metaphase–anaphase composed of chromosomal and continuous microtubules associated with the SPBs; (4) absence of a metaphase plate with chromosomes arranged randomly around a zone of continuous microtubules; (5) condensation of chromosomes and asynchronous separation at anaphase; (6) kinetochores at anaphase; (7) the nuclear envelope remaining intact throughout meiosis except for discontinuities at the SPBs; (8) membrane-bound vesicles associated with chromosomes during division; and (9) separation of daughter nuclei at telophase. Stages of division II meiosis were observed less frequently and were similar to division I. The four postmeiotic nuclei then migrated back toward the central part of the basidium. Sterigmata developed at this time. Postmeiotic nuclei were surrounded by one or two envelopes of perinuclear endoplasmic reticulum before their migration into basidiospores. Electron-opaque inclusions occurred within the nuclei at this stage.
Endogenous rhythmic activity of nitrate reductase in a selection of Chenopodium rubrum
Authors: Cohen A. S. , Cumming B. G.
Published: March 2008

Oscillations of nitrate reductase (NR) activity occurred after transfer of seedlings of Chenopodium rubrum L., ecotype 60°47′ N 137°32′ W, from an alternating temperature and light intensity germination program to constant temperature and light conditions; there were peaks of activity at 18, 30, and 45 h. The presence of half-strength Hoagland's nutrient solution during the germination period increased the range of the oscillations but did not affect the period. Changes in levels of nitrate and nitrite within the seedlings were consistent with the periodicity of NR activity during the light period after germination. Enzyme activity decreased if seedlings were placed in darkness, but the phasing of the oscillations was not altered by the transition from light to darkness. In addition, oscillations of NR activity with a period length of about 18 h occurred during continuous light after dark periods. This secondary rhythmicity is apparently superimposed upon the pattern of fluctuations previously established.On the basis of the rhythmicity that is characterized by these findings, and also in the light of other previously observed effects of altered environmental conditions on the activity of NR, hypotheses are presented to account for the endogenous oscillations of NR activity in Chenopodium rubrum. It is suggested that such rhythmic behavior of NR may occur in higher plants in general.
The taxonomy of Carex series Lupulinae in Canada
Authors: Reznicek A. A. , Ball P. W.
Published: March 2008

Carex series Lupulinae consists of six species, four of which, C. grayi Carey, C. intumescens Rudge, C. lupuliformis Sartwell, and C. lupulina Willdenow, occur in Canada. It is shown that the characters most frequently used to separate these species, i.e., habit, shape of the pistillate spike, and style contortion, are unsatisfactory, but that other characters such as the length of the leaf sheath, the beak of the perigynium, and achene shape do afford a reliable separation of the species. The diploid chromosome numbers of the four Canadian species were found to be as follows: C. grayi 2n = 52, 54; C. intumescens 2n = 48; C. lupulina 2n = 56; and C. lupuliformis 2n = 60. Distribution maps of these four species are also given.
A new Blepharandra shrub (Malpighiaceae) from Venezuela
Authors: MacBryde Bruce
Published: March 2008

A species of Blepharandra (Malpighiaceae) new to science is reported and briefly discussed in relation to its genus and subtribe. A key to the species recognized in the genus is provided.
The response of plant species to burial in three types of Alaskan wetlands
Authors: Valk A. G. van der , Swanson Steven D. , Nuss Richard F.
Published: March 2008

At 15 freshwater lowland, 7 coastal, and 6 alpine sites, a burial experiment was set up with four treatments (0, 5, 10, or 15 cm of sediment). Species in alpine wetlands were damaged most by burial and their average shoot density in the 5-, 10-, and 15-cm treatments was reduced 35, 72, and 93% in 1979 and 28, 54, and 81% in 1980, respectively. In coastal wetlands, the average shoot density was 33, 65, and 76% lower in 1979 and 21, 37, and 53% in 1980 in the 5-, 10-, and 15-cm treatments. Species in freshwater lowland wetlands were the least damaged by burial: average shoot density was 17, 33, and 47% lower in 1979 and 10, 7, and 39% lower in 1980 in the 5-, 10-, and 15-cm treatments. The responses of three common species (Carex aquatilis, Carex lyngbyaei, and Equisetum fluviatile) to burial varied from site to site. For example, Equisetum fluviatile responded to burial with a significant increase in shoot density at two permanently flooded sites and with no change in shoot density or with a significant decrease in shoot density at sites flooded seasonally. Only eight species at five sites (mostly alpine sites) were eradicated and only in the 10- and (or) 15-cm treatments at any site. In seed traps in 1979 an average of 2.7, 3.6, and 5.9 species became established at alpine, coastal, and freshwater lowland sites, respectively. In 1980, there were 1.2, 4.1, and 7.3 species, on the average, represented in the seed traps in these three types of wetlands. Average seedling density was lowest in the alpine seed traps (6/m2 in 1979 and 7/m2 in 1980) and highest in coastal wetlands (362/m2 in 1979 and 270/m2 in 1980). In freshwater lowland wetlands, those with permanent standing water averaged 2.2 and 3.0 species in their seed traps in 1979 and 1980, respectively, while those only seasonally flooded averaged 8.8 species in 1979 and 9.0 in 1980. Permanently flooded freshwater lowland wetlands had 7 seedlings per square metre in 1979 and 25 in 1980, while those flooded seasonally had 122 seedlings per square metre in 1979 and 69 in 1980. On the average, slightly more than 40% of the taxa in the seed traps at a site in 1980 were taxa that had not been present in 1979, and slightly less than 40% of the taxa present in 1979 were not present in the seed traps at the same site in 1980. Only a few individuals of four species present in the seed traps of coastal wetlands in 1979 were still present in 1980.
Development of protein bodies in oat starchy endosperm
Authors: Saigo Roy H. , Peterson David M. , Holy Jon
Published: March 2008

The development of protein bodies in the starchy endosperm of oat (Avena sativa L.) was studied by an ultrastructural examination of the subaleurone layer at various stages of maturation. In caryopses of 11 mg fresh weight, cells were highly vacuolate with little evidence of protein deposition. By 18 mg, vacuoles were smaller, rough endoplasmic reticulum (RER) was evident, and some vacuoles contained protein deposits. As the caryopsis matured, protein deposits filled a greater proportion of the vacuolar space. Small protein deposits were observed within the cistemae of the RER, and direct connections between the RER and the tonoplast of vacuoles were evident. Dictyosomes were infrequently observed at any stage. The electron micrographs are consistent with the hypothesis that protein synthesized on the membrane-bound ribosomes is transported within the ER cisternae to the vacuoles, where it condenses, forming protein bodies.
Inner surface sculpture patterns of cuticles in Cupressaceae
Authors: Oladele F. A.
Published: March 2008

Chemically and enzymatically isolated cuticles in the family Cupressaceae were examined with a scanning electron microscope (SEM). The inner surface of the cuticles has many micromorphological characters which show interspecific and intergeneric variations. Those above the generic level are less apparent. Taxonomic significance of the sculpture patterns is discussed.
The role of temperature and its relationship with gibberellic acid in the development of floral organs of tomato (Lycopersicon esculentum)
Authors: Sawhney V. K.
Published: March 2008

The role of different temperature regimes (low, 18 °C day: 15 °C night (LTR); intermediate, 23 °C day: 18 °C night (ITR); and high, 28 °C day: 23 °C night (HTR)) in the development of tomato (Lycopersicon esculentum Mill.) flowers was studied. In general, flowers produced in LTR contained significantly greater numbers of petals, stamens, carpels, and locules than did plants grown in HTR. In ITR, the number of these organs was intermediate to plants grown in LTR and HTR, but was not significantly different from them in all cases. Gibberellic acid (GA3) also induced an increase in the number of petals, stamens, carpels, and locules; however, its effect was much greater on plants grown in ITR and HTR than on LTR, implying that LTR may produce at least part of its effect through increased levels of endogenous gibberellins. The intensity of response to different temperature regimes was variable for each of the three cultivars studied.
Ca2+handling and oxidative capacity are greatly impaired in swimming muscles of hatchery-reared versus wild Atlantic salmon (Salmo salar)
Authors: Anttila Katja , Järvilehto Matti , Mänttäri Satu
Published: March 2008

The swimming capacity of fish is strongly associated with muscle performance, although the prerequisites for effective movements have not been fully described at the molecular level. To compare the condition of swimming musculature of hatchery-reared Atlantic salmon (Salmo salar) with that of wild fish, we analyzed the relative level of two excitation–contraction coupling components (i.e., dihydropyridine receptor (DHPR) and ryanodine receptor (RyR)) and the oxidative capacity of muscles with histochemical and Western blot methods. The density of DHPR and RyR was considerably higher in swimming muscles of wild fingerlings (age 0+) (109.8% and 123.3% in red muscle; 128.6% and 186.0% in white muscle, respectively) and yearlings (age 1+) (153.5% and 459.1% in red muscle; 131.2% and 858.4% in white muscle) as compared with those in reared fish. Similar difference was also observed in the oxidative capacity of muscles. Moreover, the oxidative activity correlated positively with the level of DHPR and RyR. Our data indicate that calcium handling, as well as oxidative capacity of swimming muscles of reared salmon, is clearly separable from the corresponding capacities of wild fish. We suggest that the observed alteration is a major contributing factor to the well-documented differences in swimming ability between wild and hatchery-reared salmon.
Behavioral inferences from the statistical distribution of commercial catch: patterns of targeting in the landings of the Dutch beam trawler fleet
Authors: Gillis Darren M , Rijnsdorp Adriaan D , Poos Jan Jaap
Published: March 2008

The objective identification of targeting behavior in multispecies fisheries is critical to the development and evaluation of management measures. Here, we illustrate how the statistical distribution of commercial catches can provide information on species preference that is consistent with economic data but not a simple function of price. Using the Dutch beam trawl fishery from 1998 to 2003, we show that the distribution of the log10-transformed catch rates of preferred species exhibit greater negative skews than less preferred species. Furthermore, subsets of the fleet employing spatially distinct strategies generate the expected patterns in the skews of their catch distributions. A simple model is presented to illustrate a behavioral mechanism for variation in skews and identify circumstances where it could apply. As a result of this analysis we propose that (i) catch distributions should be examined by species when investigating targeting behavior and (ii) changes in error structure over time can be expected in comparisons of catch statistics such as those used to create abundance indices or estimate fishing power.
Growth, temperature, and density relationships of North Sea cod (Gadus morhua)
Authors: Rindorf Anna , Jensen Henrik , Schrum Corinna
Published: March 2008

This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related to temperature; however, although temperature increased, distribution of 1-year-olds changed concurrently and no increase in length at age 1 occurred. Growth from age 1 to age 2 decreased as ambient biomass of sandeel and density of cod decreased, whereas growth of cod older than 2 years decreased with increasing density of cod and increased with increasing biomass of demersal fish prey. Though growth of juveniles was strongly positively correlated to ambient temperature, no indication of direct temperature limitation of growth of older North Sea cod was found.
The response of two remote, temperate lakes to changes in atmospheric mercury deposition, sulfate, and the water cycle
Authors: Watras C J , Morrison K A
Published: March 2008

Atmospheric deposition is the ultimate source of Hg to many remote lakes, but the response to depositional change remains uncertain because of potential buffering by historical pools of Hg in sediments and soils. We investigated the responsiveness of two lakes over time scales ranging from weeks to decades. For waterborne Hg, results indicated that a precipitation-dominated seepage lake and a wetland-dominated drainage lake responded similarly to depositional change, despite high loadings of terrigeneous matter to the drainage lake. For methylmercury (meHg), the response was more complicated, reflecting the influence of multiple factors on in-lake methylation. In the seepage lake, waterborne meHg was correlated with the atmospheric deposition of Hg(II) and SO4, and there was an indirect dependence on the water cycle. In the drainage lake, although wetland export was always the dominant external source of meHg, mass balance indicated that net in-lake methylation was four- to seven-fold greater than loading from the wetland. However, in-lake meHg production was related to the export of Hg(II), SO4, dissolved organic carbon, and P from the wetland to the lake. The results suggest that atmospheric Hg deposition, weather, and microbial activity interactively effect the aquatic mercury cycle in ways that can be independent of historical pools of Hg in catchments.
Evaluation of visual survey methods for monitoring Pacific salmon (Oncorhynchus spp.) escapement in relation to conservation guidelines
Authors: Holt Kendra R , Cox Sean P
Published: March 2008

Canada’s Wild Salmon Policy requires that biological status of conservation units of Pacific salmon (Oncorhynchus spp.) be assessed regularly in relation to abundance-based benchmarks. Visual survey methods, in which periodic counts of spawning fish are made throughout a season, will likely be used for this purpose because they provide a cost-effective means of monitoring interannual trends in escapement. Trend detection performance for visual survey methods depends mainly upon consistency in (i) the ability of observers to detect fish and (ii) the annual timing of fish presence in the survey area. We developed a Monte Carlo simulation procedure to evaluate the ability of four visual survey methods (peak count, mean count, trapezoidal area-under-the-curve (AUC), and likelihood AUC) to detect 30% declines in coho salmon (Oncorhynchus kisutch) escapement over 10 years (i.e., the magnitude of trend that would warrant listing a coho population as threatened using the listing criteria of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC)) given realistic levels of variability in these two factors. The mean count outperformed all other approaches across a wide range of scenarios about true population dynamics and survey designs, suggesting that a simple mean count method is suitable for monitoring coho escapements in relation to COSEWIC guidelines.
Life history variation parallels phylogeographical patterns in North American walleye (Sander vitreus) populations
Authors: Zhao Yingming , Shuter Brian J , Jackson Donald A
Published: March 2008

Walleye (Sander vitreus) is a native fish species in North America, and its zoogeographic range covers several climatic zones. Using multivariate statistical approaches and published growth data, we explored the association between climatic conditions (frost frequency, precipitation, air temperature, solar radiation, and cloud cover) and growth of walleye from 89 populations in North America. We found significant concordance between climatic conditions and walleye growth; however, the pattern of concordance differed among populations that originated from geographical regions that were colonized from different glacial refugia. This suggests that contemporary differences in walleye growth patterns related to local climatic conditions may have been shaped by evolutionary divergence that occurred among refugia during the last glaciation. We suggest that caution should be taken when assessing possible effects of climate variation and climate change on the life history traits of different walleye and other fish populations, especially when such assessments potentially include several genetically distinct groups. Procrustes analysis was shown to be an effective tool for characterizing how a multivariate set of response variables change in response to generalized changes in a multivariate set of independent variables.
The impact of the sandeel fishery closure on seabird food consumption, distribution, and productivity in the northwestern North Sea
Authors: Daunt Francis , Wanless Sarah , Greenstreet Simon P.R. , Jensen Henrik , Hamer Keith C , Harris Michael P
Published: March 2008

In the North Sea, the lesser sandeel (Ammodytes marinus) is the target of an industrial fishery and the principal prey of many top predators. Because of concerns about potential effects on predators, the sandeel fishery off eastern Scotland was closed in 2000, and local sandeel abundance increased subsequently. To examine whether closure benefitted sandeel-dependent seabirds, we compared summer sandeel consumption, at-sea distributions, and breeding success of seven species with fishery removals and abundance of older (1+ group) and young-of-the-year (0 group) sandeels from 1996 to 2003. Breeding success of black-legged kittiwake (Rissa tridactyla), a species that has declined in recent decades, was related to abundance of both 1+ group (the age class targeted by the fishery) and 0 group sandeels. The proportion of 0 group consumed by kittiwakes and proportion of the kittiwake population foraging in the area were linked to 0 group abundance. None of these parameters in the other seabird species were associated with sandeel abundance. Our results suggest that fishery closure can have a beneficial impact on top predators sensitive to variation in abundance of the target species, although environmental conditions before and after closure are also likely to be critically important.
Landscape influences on stream fish assemblages across spatial scales in a northern Great Plains ecoregion
Authors: Wilson Henry F , Xenopoulos Marguerite A
Published: March 2008

We examined the relationship between multiple spatial scales of fish assemblage structure and land cover in streams of a northern Great Plains ecoregion. We used regional richness measurements, an index of biotic integrity (IBI), and nonmetric multidimensional scaling (NMS) ordination to characterize fish assemblages. These metrics were related to regional catchment landscape at two spatial scales (overall catchment, overall riparian) and then to a set of local subcatchments from within these catchments at three scales (overall subcatchment, overall riparian buffer, and reach). Relationships between catchment fish richness, IBI scores, and landscape predictors were strongest at the riparian scale, with the strongest single predictor being riparian forest (r2 = 0.63, P < 0.01). NMS ordination analysis showed clear similarities between fish species assemblages in agriculturally dominated catchments and assemblages found in smaller headwater streams. At the same time, forested catchments and catchments with larger areas exhibited similar fish species assemblages. Our results indicate that both local and regional stream fish assemblages are structured by broader-scale landscape characteristics, with land cover providing a better indication of overall available habitat volume than catchment area or stream order.
Periphyton as an early indicator of perturbation in recreational lakes
Authors: Lambert Daniel , Cattaneo Antonella , Carignan Richard
Published: March 2008

We looked for empirical relationships between periphyton biomass and recreational development in the Laurentian lakes of Quebec (Canada). We compared the response of periphyton (as chlorophyll a) on rocks and sediments with that of phytoplankton. Epilithon and epipelon biomass increased significantly with lake recreational development (as percentage of cleared land within a 50 m riparian strip) but was not related with open-water phosphorus concentration. In contrast, phytoplankton was related to open-water phosphorus but did not increase along the gradient of lake development. Periphyton stoichiometric composition also changed with increasing lake development. High C:P and C:N ratios were found in pristine lakes, whereas lower periphyton molar ratios, which approached the optimal stoichiometric composition for benthic microalgae, were observed in the most developed lakes. Our findings suggest that periphyton, positioned near the land–water interface, has access to land-derived nutrients before they are diluted in the open water. Therefore, periphyton on all substrata is the first community to respond to increased inputs resulting from lake recreational development. The measurement of littoral algal biomass and chemical composition may represent a better tool for early detection of lake perturbation than classic methods based on pelagic characteristics.
The spatial scale of phase synchrony in winter flounder (Pseudopleuronectes americanus) production increased among southern New England nurseries in the 1990s
Authors: Manderson John P
Published: March 2008

The spatial scales at which the dynamics of subpopulations are synchronized affect regional population persistence and reflect the operational spatial scales of factors regulating populations. I examined phase synchrony in the fluctuations of age-0 winter flounder (Pseudopleuronectes americanus) production among 19 southern New England (SNE), USA, coastal nurseries. From 1990 to 2004, nursery production was synchronized at scales up to ~200 km based on spatial trends in cross-correlations of first-differenced age-0 abundance time series. However, sliding window analysis of 1975–2005 time series collected in six nurseries ≤55 km apart in northern SNE indicated that synchrony increased from low to high values in the early 1990s. Synchrony in production also increased among three nurseries ≤65 km apart in southern SNE from 1984 to 2004. Thus, interannual fluctuations in nursery production appeared to become synchronized at coarser spatial scales throughout SNE during the 1990s. This coarsening of the spatial scale of control of winter flounder nursery production was coincident with an increase in the frequency of springs with warm temperatures believed to negatively affect early life history processes. Spatial synchronization of winter flounder nursery ground production could destabilize the age-class structure and population dynamics in the region.
Modelling the trajectories of migrating Atlantic salmon (Salmo salar)
Authors: Booker Douglas J , Wells Neil C , Smith I Philip
Published: March 2008

This paper describes a model for simulating the trajectories of migrating Atlantic salmon (Salmo salar) in the ocean. Surface current and temperature representations were used as boundary conditions for simulation of migration trajectories. Representations of surface currents were derived from a general circulation model forced by realistic winds and then tested through comparisons with observed trajectories of drifting buoys. Observed climatology data were used to represent sea surface temperature patterns. The model was used to simulate the trajectories of 15 individual salmon that were tagged in their home rivers and subsequently recaptured at sea. In contrast to a random swimming direction model, trajectories simulated using both rheotaxis and thermotaxis as direction-finding mechanisms passed close to the recapture locations of the salmon. The timings and positions of the trajectories simulated using rheotaxis corresponded more closely with the observed data than those simulated using thermotaxis. This work indicates that either rheotaxis or thermotaxis, or a combination of the two, are possible direction-finding mechanisms for migrating Atlantic salmon.
Meta-analysis of the impacts of water management on aquatic communities
Authors: Haxton Tim J , Findlay C Scott
Published: March 2008

Systematic meta-analyses were conducted on the ecological impacts of water management, including effects of (i) dewatering on macroinvertebrates, (ii) a hypolimnetic release on downstream aquatic fish and macro invertebrate communities, and (iii) flow modification on fluvial and habitat generalists. Our meta-analysis indicates, in general, that (i) macroinvertebrate abundance is lower in zones or areas that have been dewatered as a result of water fluctuations or low flows (overall effect size, –1.64; 95% confidence intervals (CIs), –2.51, –0.77), (ii) hypolimnetic draws are associated with reduced abundance of aquatic (fish and macroinvertebrates) communities (overall effect size, –0.84; 95% CIs, –1.38, –0.33) and macroinvertebrates (overall effect size, –0.73; 95% CIs, –1.24, –0.22) downstream of a dam, and (iii) altered flows are associated with reduced abundance of fluvial specialists (–0.42; 95% CIs, –0.81, –0.02) but not habitat generalists (overall effect size, –0.14; 95% CIs, –0.61, 0.32). Publication bias is evident in several of the meta-analyses; however, multiple experiments from a single study may be contributing to this bias. Fail-safe Ns suggest that many (>100) studies showing positive or no effects of water management on the selected endpoints would be required to qualitatively change the results of the meta-analysis, which in turn suggests that the conclusions are reasonably robust.
Variation in the performance of acoustic receivers and its implication for positioning algorithms in a riverine setting
Authors: Simpfendorfer Colin Ashley , Heupel Michelle RaNae , Collins Angela B
Published: March 2008

The performance of an array of data-logging single frequency acoustic receivers in the Caloosahatchee River (Florida, USA) was examined and the results incorporated into a positioning algorithm for animals tracked within the system. The mean code detection efficiency across all individual receivers and all download periods was 0.414 detections per synchronization code. On average, the code rejection coefficient was approximately 4%, indicating that it was only a minor factor in reducing code detection efficiency. There were significant performance differences between stations and download periods, but no interaction between these two factors for all three metrics. Code detection efficiency, the rejection coefficient, and the noise quotient all showed significant variations with distance from the river mouth and time since deployment. Comparison of position estimates with and without efficiency produced small differences for bull sharks (Carcharhinus leucas) and cownose rays (Rhinoptera bonasus) monitored via this system. Root mean square errors were higher for cownose rays (48 m) than for bull sharks (23 m). Mean differences for individuals were always slightly downstream because of the increasing code detection efficiency of upriver receivers. The results of this comparison indicated that the inclusion of code detection efficiency did not significantly improve the results of the positioning algorithm.
New estimates of lethality of sea lamprey (Petromyzon marinus) attacks on lake trout (Salvelinus namaycush): implications for fisheries management
Authors: Madenjian Charles P , Chipman Brian D , Marsden J Ellen
Published: March 2008

Sea lamprey (Petromyzon marinus) control in North America costs millions of dollars each year, and control measures are guided by assessment of lamprey-induced damage to fisheries. The favored prey of sea lamprey in freshwater ecosystems has been lake trout (Salvelinus namaycush). A key parameter in assessing sea lamprey damage, as well as managing lake trout fisheries, is the probability of an adult lake trout surviving a lamprey attack. The conventional value for this parameter has been 0.55, based on laboratory experiments. In contrast, based on catch curve analysis, mark–recapture techniques, and observed wounding rates, we estimated that adult lake trout in Lake Champlain have a 0.74 probability of surviving a lamprey attack. Although sea lamprey growth in Lake Champlain was lower than that observed in Lake Huron, application of an individual-based model to both lakes indicated that the probability of surviving an attack in Lake Champlain was only 1.1 times higher than that in Lake Huron. Thus, we estimated that lake trout survive a lamprey attack in Lake Huron with a probability of 0.66. Therefore, our results suggested that lethality of a sea lamprey attack on lake trout has been overestimated in previous model applications used in fisheries management.
Degree of aquatic ecosystem fragmentation predicts population characteristics of gray snapper (Lutjanus griseus) in Caribbean tidal creeks
Authors: Rypel Andrew L , Layman Craig A
Published: March 2008

Ecosystem fragmentation is one of the most damaging anthropogenic impacts to aquatic and terrestrial ecosystems worldwide. In this study, we analyzed population-level characteristics of a resilient top predator, the gray snapper (Lutjanus griseus), across a gradient of fragmentation in Bahamian tidal creeks. Analysis of hydrologic connectivity (the inverse of fragmentation) and site-specific population parameters revealed that varying degrees of connectivity translated into predictable characteristics in fish populations. Less-fragmented systems produced fast-growing snapper with high condition factors, whereas more fragmented tidal creeks yielded slow-growing snapper with low condition factors. Underlying reasons for growth rate differences likely originated from structural and functional shifts in tidal creek ecosystems following fragmentation. Such ecosystem-level shifts were reflected by low per-individual volumes of consumed prey, as well as increased parasite infestations. Results indicated that aquatic ecosystem fragmentation may affect long-term fitness and viability of resilient species capable of persisting in fragmented habitats. Our results from estuarine tidal creeks compare well with studies on fragmentation of freshwater streams by dams and suggest that population-level consequences following ecosystem fragmentation may be generalizable between seemingly disparate aquatic environments.
The influence of air temperature, groundwater discharge, and climate change on the thermal diversity of stream fishes in southern Ontario watersheds
Authors: Chu Cindy , Jones Nicholas E , Mandrak Nicholas E , Piggott Andrew R , Minns Charles K
Published: March 2008

The availability of suitable thermal habitat for fishes in streams is influenced by several factors, including flow, channel morphology, riparian vegetation, and land use. This study examined the influence of air temperature and groundwater discharge, predictors of stream temperature, on the thermal diversity (cold-, cool-, and warm-water preferences) of stream fish communities in southern Ontario watersheds. Site-level fish sampling data were used to assess the thermal diversity of 43 quaternary watersheds using three metrics, the proportion of sites within a watershed having (i) cold-, (ii) cool-, and (iii) warm-water fishes. Our results indicated that 53.9% of the variances in cold-water and 54.1% of the variances in warm-water fish distributions within the watersheds could be attributed to groundwater discharge and air temperature variables. Climate change scenarios suggested that watersheds with high groundwater discharge and the associated thermal diversity of fishes within those watersheds are less sensitive to climate change than watersheds with low groundwater discharge. Conservation of groundwater resources will be required to lessen climate change impacts on the thermal habitat and thermal diversity of stream fishes in southern Ontario watersheds.
Enriched stable isotope marking of juvenile golden perch (Macquaria ambigua) otoliths
Authors: Munro Andrew R , Gillanders Bronwyn M , Elsdon Travis S , Crook David A , Sanger Andrew C
Published: March 2008

Stocking of native fish is a standard practice to aid in the recovery and enhancement of depleted populations. However, evaluating the effectiveness of these stocking programs has been hindered because of difficulty in distinguishing hatchery from wild fish, especially for species that are stocked as small, fragile fingerlings. Stable isotopes offer the potential to chemically mark fish with multiple marks that are distinct from each other and from natural signatures. Golden perch (Macquaria ambigua) fingerlings were reared in water enriched in 137Ba and combinations of 137Ba and 86Sr for various lengths of time. Ba and Sr isotopic ratios in the otoliths were determined using laser ablation inductively coupled plasma-mass spectrometry. Fish exposed to increased levels of 137Ba had lower 138Ba/137Ba ratios in their otoliths relative to the natural ratio of control fish and were significantly different in fish exposed to at least 5 µg·L-1 for 8 days or to 15 µg·L-1 for 4 days. Furthermore, eight unique signatures were produced in fish reared in combinations of 137Ba (0–5 µg·L-1) and 86Sr (0–100 µg·L-1) for 24 days. Our results suggest that immersion in water enriched in specific stable isotopes could be an effective means of marking hatchery-reared fish for stock enhancement.
Asymptotic behavior of eigen energies of non-Hermitian cubic polynomial systems
Authors: Nanayakkara A
Published: March 2008

The asymptotic behavior of the eigenvalues of a non-Hermitian cubic polynomial system H = (P2/2) + µx3 + ax2 + bx, where µ, a, and b are constant parameters that can be either real or complex, is studied by extending the asymptotic energy expansion method, which has been developed for even degree polynomial systems. Both the complex and the real eigenvalues of the above system are obtained using the asymptotic energy expansion. Quantum eigen energies obtained by the above method are found to be in excellent agreement with the exact eigenvalues. Using the asymptotic energy expansion, analytic expressions for both level spacing distribution and the density of states are derived for the above cubic system. When µ = i, a is real, and b is pure imaginary, it was found that asymptotic energy level spacing increases with the coupling strength a for positive a while it decreases for negative a.

PACS Nos.: 03.65.Ge, 04.20.Jb, 03.65.Sq, 02.30.Mv, 05.45
About the simulation of primary grown-in microdefects in dislocation-free silicon single-crystal formation
Authors: Talanin V I , Talanin I E , Voronin A A
Published: March 2008

A mathematical model of primary grown-in microdefects formation is proposed. The model is built on the basis of the dissociative process of diffusion. Here, we study the interaction patterns between oxygen-vacancy (O + V) and carbon-interstitial (C + I) near the crystallization front in dislocation-free silicon monocrystals grown by float-zone and Czochralski methods. As shown here, the approximate analysis formulas obtained tally with the heterogeneous mechanism of grown-in microdefects formation.

PACS Nos.: 61.72Bb, 61.72.Jj, 61.72.Yx
Tests of quantum electrodynamics with EBIT
Authors: Sapirstein J , Cheng K T
Published: March 2008

A Feynman-diagram-based approach to calculating the spectra of highly charged ions is described and applied to lithiumlike and sodiumlike ions. Discrepancies between calculations excluding the two-loop Lamb shift and experiment allow that shift to be determined, as the accuracy of EBIT experiments is well below the size of the effect. The present status of the theory of hyperfine splitting is described, where a large quantum electrodynamics (QED) effect is made difficult to observe because of nuclear physics uncertainties. The importance of a correct treatment of nuclear recoil at present levels of accuracy is stressed, and prospects for a full QED treatment of copperlike ions are discussed. PACS Nos.: 31.30.Jv, 32.30.Rj, 31.25.–v, 31.15.Ar
Applications of EBIT to magnetic fusion diagnostics
Authors: Skinner C H
Published: March 2008

Fusion-energy development has reached an exciting stage with the agreement by seven nations, representing over half the world population, to build the International Thermonuclear Experimental Reactor (ITER) and demonstrate the scientific and technological feasibility of magnetic fusion. High-Z materials such as tungsten are used in plasma-facing components, and contamination of the plasma by sputtered impurities must be controlled to limit radiation losses. Spectroscopic diagnostics will be used to monitor impurity influx and EBIT has played a key role in generating the atomic data necessary to interpret the spectroscopic observations. In this paper, we focus on the key contributions that EBIT devices are uniquely positioned to make in the spectroscopic diagnostics of next-step burning plasmas such as ITER and list specific areas where new data are needed. PACS Nos.: 32.30.Jc, 32.30.Rj, 52.40.Hf, 52.55.Fa, 52.70.Kz, 52.70.La
SIMCV un simulateur analogue de la propagation du son dans le conduit vocal
Authors: Teffahi H
Published: March 2008

Wave propagation in a vocal tract incurring losses with yielding walls is studied. The simulation method of this vocal tract is described. The adopted method allowed us to calculate the transfer function, the formant frequencies, and the formant bandwidths of the vocal tract. The results obtained permit the determination of the differential contribution of the different loss sources for formant frequencies and formant bandwidths.
Recent activities at the Tokyo EBIT 2006
Authors: Nakamura N , Currell F J , Kato D , Kavanagh A P , Li Y M , Ohtani S , Sakaue H A , Sakurai M , Sun J , Takahashi S , Tona M , Watanabe H , Yamada C , Yoshiyasu N
Published: March 2008

The electron beam ion trap (EBIT) in Tokyo was constructed about 10 years after the first EBIT at Lawrence Livermore National Laboratory was built, and has been being stably operated since then. In this paper, we present recent experimental activities at the Tokyo EBIT. In particular, experiments utilizing slow, very highly charged ion beams extracted from the EBIT are reported. PACS Nos.: 39.10.+j, 32.30.Rj, 34.50.Dy, 34.80.Kw
The visible spectrum of highly charged ions: A window to fundamental physics
Authors: López-Urrutia J.R. Crespo
Published: March 2008

The observation of forbidden transitions in the visible range was the first experimental sign of the existence of highly charged ions in nature. Such lines can nowadays be excited in electron beam ion traps with excellent control of the ionic charge state, allowing their identification and precise determination of wavelengths and transition probabilities. The accuracy achieved in such experiments has been central to the study of nuclear size effects and quantum electrodynamic contributions, which are drastically magnified in highly charged ions, thus enabling the study of the underlying fundamental interactions in few-electron systems. At the same time, forbidden lines can be used to probe conditions in high temperature plasmas present in both astrophysical and laboratory environments.PACS Nos.: 31.30.Jv, 32.10.Fn, 32.30.Jc, 96.60.Tf, 97.10.Ex, 32.60.+i, 32.70.Cs, 12.20.Fv, 42.50.Xa