bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of bicycle helmet legislation to increase helmet use: a systematic review
Authors: Karkhaneh M , Kalenga J-C , Hagel B E , Rowe B H
Published: April 2006

Background:Head injuries related to bicycle use are common and can be serious. They can be prevented or reduced in severity with helmet use; however, education has resulted in modest helmet use in most developed countries. Helmet legislation has been proposed as a method to increase helmet wearing; while this social intervention is thought to be effective, no systematic review has been performed.

Objectives:This review evaluates the scientific evidence for helmet use following legislation to identify the effectiveness of legislative interventions to increase bicycle helmet use among all age groups.

Search strategy:Comprehensive searches of CENTRAL, MEDLINE, EMBASE, CINAHL, Web of Science, British Education Index, LILACS Database, TRIS (Transport Research Information Service), the grey literature, reference lists, and communication with authors was performed to identify eligible studies.

Selection criteria:Eligible studies for this review were community based investigations including cohort studies, controlled before-after studies, interrupted time series studies, non-equivalent control group studies

Data collection and analysis:Two reviewers extracted the data regarding the percentage of helmet use before and after legislation from each study. Individual and pooled odds ratios were calculated along with 95% confidence intervals.

Main results:Out of 86 prescreened articles, 25 were potentially relevant to the topic and 11 were finally included in the review. Of 11 studies, eight were published articles, two were published reports, and one was an unpublished article. One additional survey was incorporated following personal communication with the author. While the baseline rate of helmet use among these studies varied between 4% and 59%, after legislation this range changed to 37% and 91%. Helmet wearing proportions increased less than 10% in one study, 10–30% in four studies, and more than 30% in seven studies. While the effectiveness of bicycle helmet legislation varied (n = 11 studies; OR range: 1.2–22), all studies demonstrated higher proportions of helmet use following legislation, particularly when the law was targeted to a specific age group.

Conclusions:Legislation increased helmet use among cyclists, particularly younger age groups and those with low pre-intervention helmet wearing proportions. These results support legislative interventions in populations without helmet legislation.
Hsulf-1 regulates growth and invasion of pancreatic cancer cells
Authors: Abiatari I , Kleeff J , Li J , Felix K , Büchler M W , Friess H
Published: April 2006

Background:Hsulf-1 is a newly identified enzyme with arylsulphatase activity that can regulate the sulphation state of cell-surface heparan sulphate proteoglycans (HSPGs). In vitro overexpression of this enzyme in pancreatic cancer cells decreases responsiveness to fibroblastic growth factor-2, as Hsulf-1 is up regulated in primary pancreatic adenocarcinoma.

Aim:To further analyse the functions of the Hsulf-1 enzyme in vitro and in vivo with respect to growth, invasion and tumorigenicity.

Methods and results:Transfection of Panc-1 pancreatic cancer cells with a full-length Hsulf-1 expression vector resulted in increased invasiveness and adhesiveness. An in vivo xenograft nude mouse tumour model showed a markedly reduced growth potential of Hsulf-1-expressing Panc-1 cells, which correlated with a considerably lower proliferation rate. Hsulf-1-positive nude mouse tumours showed better development of interstitial matrix structures, with increased blood vessel density in these tumours. In an orthotopic model, Hsulf-1-positive tumours exhibited enhanced local invasiveness. In human primary pancreatic cancers there was strong staining for sulphated HSPGs, which was markedly reduced in metastatic tissue samples.

Conclusion:Hsulf-1-mediated desulphation of HSPGs reduces the growth ability of Panc-1 pancreatic cancer cells, but increases the basal invasiveness of these cells, suggesting an important role of this enzyme in pancreatic cancer progression.
Use of rapid diagnostic tests for diagnosis of malaria in the UK
Authors: Chilton D , Malik A N J , Armstrong M , Kettelhut M , Parker-Williams J , Chiodini P L
Published: April 2006

Background:Malaria is currently diagnosed almost exclusively by microscopy in clinical laboratories. The introduction of rapid diagnostic tests (RDTs) may be useful in achieving rapid detection of malaria parasites, especially in situations where malaria is not often seen or where staff are inexperienced.

Aim:To explore the use of RDT in UK laboratories.

Methods:The current use of RDTs was surveyed in UK laboratories subscribing to the United Kingdom National External Quality Assessment Scheme blood parasitology and haematology schemes.

Results:An overall survey response rate of 60.3% was seen. RDTs were found to be the preferred choice, either alone or in conjunction with microscopy in 31.2% of the samples examined during normal working hours and in 44.3% of the specimens examined on call.

Conclusions:During on-call hours, the use of RDTs was observed to increase and RDTs changed the diagnosis in 12% of laboratories. No established protocol for RDT use was, however, observed in the UK. A protocol that needs to be validated in the laboratory setting is suggested.
Sediment delivery in managed forests: a review
Authors: Croke J C , Hairsine P B
Published: April 2006

The opening or removal of forest canopies during harvesting or land clearing results in a predictable sequence of responses, the descriptions of which appear remarkably similar around the world. Such activities are now widely acknowledged to have adverse impacts upon water quality and in-stream ecology. Sediment delivery, therefore, encapsulates the dominant process by which water resources are impacted and the process that can be best managed to limit off-site impacts. This paper is a review of current processes, and perceptions, of sediment delivery in managed forests. We outline the major components of sediment and runoff delivery as they relate specifically to timber harvesting activities. Whilst much existing research has focused upon soil loss as the major component of timber harvesting impacts, this review highlights both the need for, and benefits from, a conceptual advance in our thinking of sediment delivery. We advocate that by managing runoff delivery pathways and the resultant pattern of hydrological connectivity, we can limit the potential adverse effects of forest harvesting on in-stream water quality. Specific attention is given here to the interaction of the forest road and track network with both sediment and runoff delivery. The result is a comprehensive account of how best to manage timber harvesting for both on-site sustainability and off-site water resource protection.Key words: timber harvesting, sediment delivery, road network, connectivity, best management practices (BMPs).
Replication of positive-strand RNA viruses in plants: contact points between plant and virus components
Authors: Sanfaçon Hélène
Published: April 2006

Positive-strand RNA viruses constitute the largest group of plant viruses and have an important impact on world agriculture. These viruses have small genomes that encode a limited number of proteins and depend on their hosts to complete the various steps of their replication cycle. In this review, the contact points between positive-strand RNA plant viruses and their hosts, which are necessary for the translation and replication of the viral genomes, are discussed. Special emphasis is placed on the description of viral replication complexes that are associated with specific membranous compartments derived from plant intracellular membranes and contain viral RNAs and proteins as well as a variety of host proteins. These complexes are assembled via an intricate network of protein–protein, protein–membrane, and protein–RNA interactions. The role of host factors in regulating the assembly, stability, and activity of viral replication complexes are also discussed.
Genetic structure and mating system of northernArbutus menziesii(Ericaceae) populations
Authors: Beland J.D. , Krakowski J. , Ritland C.E. , Ritland K. , El-Kassaby Y.A.
Published: April 2006

Arbutus ( Arbutus menziesii Pursh. (Ericaceae)) is the only broadleaved evergreen tree native to Canada. It occurs in three red-listed (endangered) plant communities in British Columbia (BC), threatened by urban encroachment, fire suppression, grazing, and exotic invasive species. Its growth is sensitive to environmental changes: more severe summer drought caused by climate change could further threaten this species. Amplified fragment length polymorphisms (AFLPs) were assayed in 10 populations in BC and 1 in Washington to obtain baseline population genetic and mating system data. We found that genetic diversity within populations was low (mean H = 0.094) for a woody perennial. Genetic variation among populations (FST= 0.15) was comparable to woody perennials on average (0.19). Pairwise kinship coefficients were significantly associated with distance (p < 0.01). The multilocus outcrossing rate for one BC island population was high (tm= 0.97), but inbreeding due to consanguineous matings was also quite high (tm– ts= 0.10). These data can be used to guide conservation strategies and future research priorities for arbutus.
Effects of asulam spraying on non-target ferns
Authors: Rowntree J.K. , Sheffield E.
Published: April 2006

The systemic herbicide asulam is used extensively to control the weedy fern bracken ( Pteridium aquilinum (L.) Kuhn). Other ferns were thought to be highly sensitive to asulam exposure, but there has been a dearth of experimental evidence. Eight fern species were exposed to asulam spray at three different application rates or a control of water. Asulam was applied at the recommended field application rate for bracken clearance, and at two further rates corresponding to 10 and 50 m downwind of an aerial spray event. Damage was assessed over two seasons. All ferns tested were severely damaged by exposure to the highest application rate, but sensitivity varied between species. Maximum damage occurred 1 year after spraying, and limited signs of recovery could be seen by the second season. The effects of adding the adjuvant Agral® to applications of asulam were tested on the threatened pteridophyte Pilularia globulifera L. No damage additional to that caused by exposure to asulam was observed. This work supports the view that 50 m buffer zones are sufficient to protect sensitive ferns from the effects of aerial spraying with asulam, provided that drift-reducing nozzles are used and the manufacturer’s application guidelines are observed.
The concentrations and distributions of phytic acid phosphorus and other mineral nutrients in wild-type and low phytic acid Js-12-LPA wheat (Triticum aestivum) grain parts
Authors: Joyce Charlie , Deneau Andrea , Peterson Kevin , Ockenden Irene , Raboy Victor , Lott John N.A.
Published: April 2006

Concentrations of P, phytic acid (myo-inositol hexakisphosphate, IP6), and other mineral storage elements were studied in wild-type and low phytic acid (lpa) genotype Js-12-LPA wheat (Triticum aestivum L.) embryos and rest-of-grain fractions. Environmental scanning electron microscopy images revealed a decreased average size and an increased number of aleurone layer globoids in lpa grains compared with the wild type. Energy-dispersive X-ray analyses of unfixed aleurone layer and scutellum cell cytoplasm revealed mainly C, O, P, K, and Mg in both grain types. The starchy endosperm contained virtually no P, K, or Mg, demonstrating no shift of mineral nutrients to that compartment. Scanning transmission electron microscopy – energy-dispersive X-ray analyses of scutellum and aleurone layer globoids in both genotypes revealed that P, K, and Mg were the main mineral nutrients in globoids with low amounts of Ca, Fe, and Zn. Traces of Mn were only in scutellum globoids. Total P was similar between genotypes for the rest-of-grain fractions, which are 97% of grain mass. The main inositol phosphate was IP6, but a small amount of IP5 was present. Both lpa grain fractions exhibited major reductions in IP6 compared with the wild type and a threefold increase in inorganic P. The concentration of K decreased in both fractions, while Ca increased 25% in the Js-12-LPA rest-of-grain compared with the wild type. The lack of large differences in mineral concentration and distribution between the wild type and Js-12-LPA indicates that there is no direct role of localization of IP6 synthesis in mineral distribution.
Cadmium tolerance and accumulation in the noxious weed Zygophyllum fabago
Authors: Lefèvre Isabelle , Corréal Enrique , Lutts Stanley
Published: April 2006

Zygophyllum fabago L. is an invasive weed able to proliferate in coarse mineral substrates contaminated with heavy metals. To quantify its Cd tolerance, seedlings from seeds collected from a heavy metal contaminated area in Southeast Spain were exposed for 4 weeks to a nutrient solution containing 10 µmol·L–1 CdCl2. Although Cd inhibited axillary bud development, it did not reduce plant survival or dry mass. Most of the absorbed Cd remained in the roots, but the shoots were able to accumulate up to 156 mg·kg–1 dry mass of Cd. Zygophyllum fabago was able to regulate Cd translocation from roots to shoots, where it accumulated preferentially in the older leaves. Accumulation of Cd reduced the water content and water potential in shoots, as well as osmotic potential and leaf stomatal conductance in young leaves, although the plants were able to partly adapt to reestablish a more favourable water balance after 4 weeks of stress exposure. The population displayed considerable heterogeneity, and it may be possible to select individual plants combining high biomass production and a high rate of Cd accumulation. The use of Z. fabago as a Cd-tolerant species for phytoremediation is discussed.
Reproductive biology of theIlexspecies (Aquifoliaceae) in Hong Kong, China
Authors: Tsang Anita C.W. , Corlett Richard T.
Published: April 2006

Fourteen wild species of shrubs and trees in the dioecious genus Ilex occur in Hong Kong (22°N, 114°E). All species flowered and formed fruits once each year. Sex ratios at flowering were male biased in all but one large population studied and, in most cases, this bias could not be explained by earlier flowering in males or higher female mortality. Apis cerana accounted for >87% of flower visits in all species and there was a significant positive relationship across species between the number of visits per flower per hour and the estimated mean number of flowers on a plant. The large green fruits of Ilex chapaensis Merr. were consumed only by masked palm civets, Paguma larvata, while the red or black fruits of other species were consumed by birds. The rate of fruit removal across species was positively related to sugar content and negatively related to phenolic and saponin contents. The mean number of pyrenes per fruit was 4.0–6.2 and the mean percentage of pyrenes containing seeds was 49%–90%. Most embryos were immature (heart shaped) at fruit maturity, but <50% of embryos developed further in some species. Floral investment was 0.93–5.84 times higher in male plants, but total reproductive investment was 0.62–8.3 higher in females.
The response of Vaccinium myrtillus to variations in grazing intensity in a Scandinavian pine forest on the island of Svanøy
Authors: Hegland Stein Joar , Rydgren Knut , Seldal Tarald
Published: April 2006

The impact on the performance of dwarf shrub Vaccinium myrtillus L. (bilberry) subjected to differing natural intensities of grazing by Cervus elaphus L. (red deer) was examined in a mature Scandinavian pine forest, on Svanøy, an island on the western coast of Norway. All the study sites were in forest where bilberry dominated the forest floor and no forestry activities had been carried out for several decades. Pellet group counts were used as measure of grazing intensity. Bilberry size, abundance, and fruit set, and invertebrate activity on bilberry were negatively related to grazing intensity. The responses varied between early and late summer (negative or neutral), but impact on plant size was negative throughout the season. Because of the large variation in grazing intensity represented in our study, we can, in contrast to many experimental studies, show that grazing affects the performance of bilberry even at low grazing intensities. The effect on fruit production and invertebrate activity on bilberry indicates that red deer grazing has a negative impact on the population dynamics of the plant and invertebrate herbivores.
Response of understory plant community of boreal mixedwood stands to fire, logging, and spruce budworm outbreak
Authors: Kemball Kevin J. , Wang G. Geoff , Dang Qing-Lai
Published: April 2006

The understory plant community of 63 boreal mixedwood stands in southeastern Manitoba, Canada, that were disturbed in the 1980s (21 by crown fire, 20 by logging, and 22 by severe spruce budworm ( Choristoneura fumiferana ) outbreak) were investigated. Understory plant communities that developed after fire, logging, and spruce budworm outbreak shared a large number of species (47 out of 81 identified). However, compared with fire and spruce budworm outbreak, logging promoted the rapid expansion of tall shrubs (52.7% vs. 17.2% and 29.75% coverage, respectively), particularly Corylus cornuta . Significant differences were also found between disturbance types when species coverage was compared on the basis of shade tolerance and regeneration strategy. Lower shrub coverage following fire is attributed to greater disturbance severity on the forest floor, affecting in situ propagules and competition from dense trembling aspen ( Populus tremuloides Michx.) regeneration. Lower shrub coverage following spruce budworm outbreak is attributed to slow opening of the canopy coupled with retention of a residual canopy of nonhost trees. Uniformly high shrub coverage following logging resulted in less heterogeneity and lower species diversity at both the stand and the disturbance level compared with natural disturbances. High shrub coverage may negatively impact conifer recruitment and have significant implications for future stand composition and productivity. Consideration of a natural insect outbreak model, rather than fire, for management of boreal mixedwood stands is recommended, particularly if stands are to be left to regenerate naturally.
Projected impacts of climate warming on production of lake trout (Salvelinus namaycush) in southern Yukon lakes
Authors: Mackenzie-Grieve Jody L , Post John R
Published: April 2006

We used existing models to predict changes in lake surface temperature and thermocline depth, in combination with a newly developed model to describe lake thermal profiles, to determine how thermal properties of a series of lakes located predominantly in the southern Yukon could change under three realistic climate-warming scenarios. We then used existing models to determine how relative changes in potential harvest of lake trout (Salvelinus namaycush) in southern Yukon lakes could change as availability of optimal thermal habitat was altered under the three warming scenarios. With warming, an overall decrease in availability of optimal thermal habitat and in lake trout potential harvest is predicted in southern Yukon lakes, although considerable lake-specific variation in direction and magnitude of change exists. For southern Yukon lakes overall, 2, 4, and 6 °C increases in mean annual air temperature lead to 12%, 35%, and 40% decreases in thermal habitat volume, respectively, and 8%, 19%, and 23% reductions in potential harvest, respectively.
Underwater but not out of sight: genetic monitoring of effective population size in the endangered North Sea houting (Coregonus oxyrhynchus)
Authors: Hansen Michael M , Nielsen Einar E , Mensberg Karen-Lise D
Published: April 2006

We analysed 12 microsatellite DNA loci in temporal samples (1980, 1994, and 2002) from the only remaining indigenous population of the North Sea houting (Coregonus oxyrhynchus) in the Vidaa River, Denmark. Using a novel temporal method, we estimated effective population size (Ne) to be 577.4 (90% highest posterior density limits 297.23719.8). The same method was used to estimate Neat the beginning and end of the sampled time interval, and the results were indicative of a relatively stable population. In contrast, tests for recent bottlenecks suggested population declines in the 1980 and 1994 samples, possibly reflecting declines prior to 1980 in the total North Sea houting population. To evaluate the usefulness of the two methods for routine genetic monitoring, we simulated population declines corresponding to reproduction by only 20 or 50 parents in 2002. For both simulated samples, the temporal method provided evidence for a population decline, whereas the test for bottlenecks did not suggest population decline. We conclude that the North Sea houting in the Vidaa River is not immediately threatened by inbreeding or loss of evolutionary potential, and the applied temporal method appears very useful for genetic monitoring of effective population size in endangered, isolated fish populations.
Scale-dependent movements and protection of female blue crabs (Callinectes sapidus)
Authors: Medici David A , Wolcott Thomas G , Wolcott Donna L
Published: April 2006

Little is known about the migration of female crabs (Callinectes sapidus) to spawning grounds, or how effectively they are protected by North Carolina's “spawning sanctuaries.” To investigate migration, we tagged and released a total of 2700 mature female crabs in the fall of 2001 and the summer and fall of 2002 in the three tributaries of Pamlico Sound. Tag returns indicate that females begin migration during September to November and that they probably do not complete it until the next spring. To assess site fidelity and protection of females by spawning sanctuaries, 398 tagged adult females were released in or near sanctuaries at Ocracoke and Hatteras inlets. Most recaptures occurred near the barrier islands (Outer Banks), suggesting that mobility declines once females reach euhaline waters, but recapture data also showed that crabs move over scales larger than sanctuaries and derive only temporary protection by entering sanctuaries. Ovigerous females fitted with ultrasonic pingers were tracked after release inside the boundary of Ocracoke spawning sanctuary. Crabs with orange (new) egg masses meandered over small areas, but those with eggs approaching hatching moved directly seaward. Apparently spawning sanctuaries must be large to be effective; where this is not practical (as in North Carolina), other strategies should be considered.
Bacterioplankton production, abundance, and nutrient limitation among lakes of the Mackenzie Delta (western Canadian arctic)
Authors: Spears Bryan M , Lesack Lance FW
Published: April 2006

The effects of nutrient availability and quality of dissolved organic carbon (DOC) on bacterioplankton production were assessed in six lakes with differing frequencies of river flooding. Bacterial productivity, dissolved nutrients, and DOC were tracked weekly throughout the open-water period of 2001. Inorganic nutrient (N and P) enrichment microcosm experiments were conducted to directly assess the effects of DOC quality (i.e., mixtures of colored and noncolored DOC) and inorganic nutrient limitation on bacterial productivity among the lakes. Averaged over the open-water season, both abundance and production of bacterioplankton increased with decreasing flood frequency (R2 = 0.61 and R2 = 0.78, respectively). Reduced bacterial production occurred in frequently flooded lakes, where colored DOC, light attenuation, and phosphate were high but ammonium was low. Bacterial production was greatest in infrequently flooded lakes, where noncolored DOC and ammonium were high but phosphate was low. Bacterial production was enhanced by amendments of inorganic nutrients in duplicate experiments (two-factor analyses of variance). Production was also enhanced in response to higher concentrations of either colored or noncolored DOC following release from inorganic nutrient limitation. Size fractionated (<1 µm versus >1 µm) N-debt and P-debt bioassays typically showed demand for P and release of N by bacteria in all study lakes.
Stable isotopes as an indicator of diet in omnivorous crayfish (Pacifastacus leniusculus): the influence of tissue, sample treatment, and season
Authors: Stenroth Patrik , Holmqvist Niklas , Nyström Per , Berglund Olof , Larsson Per , Granéli Wilhelm
Published: April 2006

Stable isotopes have been used to analyse food webs and (or) trace movements of animals for about 30 years. There has been some debate on the use of different tissues and treatments before isotope analysis, as well as on seasonal effects. We found different crayfish (Pacifastacus leniusculus) tissues (muscle, hepatopancreas, exoskeleton, gill, and whole body) to have different isotope values. Lipid extraction made whole-body carbon isotope values higher but had no effect on nitrogen isotope values. Acidification made whole-body isotope values lower. For crayfish, there was no seasonal or interannual variation in isotope values. In contrast to studies based on gut content analysis, we found adult crayfish to be at least as carnivorous as young-of-the-year crayfish. Earlier studies often have assumed that each food source contributes both nitrogen and carbon in equal proportions. Omnivores do not fit easily into this view. We suggest that nitrogen and carbon in an organism could come from different sources. Adopting this view for a pond food web could render crayfish both predators and detritivores as crayfish prey on nitrogen sources (other invertebrates) and consume large amounts of detritus to satisfy their carbon demand.
Cumulative impacts of seabed trawl disturbance on benthic biomass, production, and species richness in different habitats
Authors: Hiddink J G , Jennings S , Kaiser M J , Queirós A M , Duplisea D E , Piet G J
Published: April 2006

Bottom trawling causes widespread disturbance of sediments in shelf seas and can have a negative impact on benthic fauna. We conducted a large-scale assessment of bottom trawl fishing of benthic fauna in different habitats, using a theoretical, size-based model that included habitat features. Species richness was estimated based on a generalized body mass versus species richness relationship. The model was validated by sampling 33 stations subject to a range of trawling intensities in four shallow, soft sediment areas in the North Sea. Both the model and the field data demonstrated that trawling reduced biomass, production, and species richness. The impacts of trawling were greatest in areas with low levels of natural disturbance, while the impact of trawling was small in areas with high rates of natural disturbance. For the North Sea, the model showed that the bottom trawl fleet reduced benthic biomass and production by 56% and 21%, respectively, compared with an unfished situation. Because of the many simplifications and assumptions required to synthesize these data, additional work is required to refine the model and evaluate applicability in other geographic areas. Our model enables managers to understand the consequences of altering the distribution of fishing activities on benthic production and hence on food web processes.
Conservation and management of exploited shark populations based on reproductive value
Authors: Gallucci Vincent F , Taylor Ian G , Erzini Karim
Published: April 2006

Several life history traits of sharks result in juveniles being particularly vulnerable to exploitation. However, population level impacts of harvests on juvenile sharks have not been well quantified. This paper examines a range of harvest strategies, including those targeting juveniles. Reproductive value and yield per recruit are used to compare the harvests, which are represented by Leslie matrix models with a harvest matrix. Two species are used as examples: the short-lived Rhizoprionodon taylori and the long-lived Squalus acanthias. Harvests that maintain a stationary population size cause reproductive values to change in opposing ways, but they remove equal fractions of the population's reproductive potential. A new theorem gives population growth as a function of the fraction of reproductive potential removed by a harvest, a relationship useful for comparing harvests on juveniles and adults. Stochastic projections indicate that the risk of depletion is associated with the fraction of reproductive potential removed annually, a measure which encompasses the information in both the selectivity and the rate of fishing mortality. These results indicate the value of focusing conservation efforts on preserving reproductive potential.
The influence of fall-spawning coho salmon (Oncorhynchus kisutch) on growth and production of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska
Authors: Lang Dirk W , Reeves Gordon H , Hall James D , Wipfli Mark S
Published: April 2006

This study examined the influence of fall-spawning coho salmon (Oncorhynchus kisutch) on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon on the Copper River Delta, Alaska, USA. During the fall of 1999 and 2000, fish rearing in beaver ponds that received spawning salmon were compared with fish from ponds that did not receive spawners and also with fish from ponds that were artificially enriched with salmon carcasses and eggs. The response to spawning salmon was variable. In some ponds, fall-spawning salmon increased growth rates and improved the condition of juvenile coho salmon. The enrichment with salmon carcasses and eggs significantly increased growth rates of fish in nonspawning ponds. However, there was little evidence that the short-term growth benefits observed in the fall led to greater overwinter growth or survival to outmigration when compared with fish from the nonspawning ponds. One potential reason for this result may be that nutrients from spawning salmon are widely distributed across the delta because of hydrologic connectivity and hyporheic flows. The relationship among spawning salmon, overwinter growth, and smolt production on the Copper River Delta does not appear to be limited entirely to a simple positive feedback loop.
Simulating and testing the sensitivity of ecosystem-based indicators to fishing in the southern Benguela ecosystem
Authors: Travers Morgane , Shin Yunne-Jai , Shannon Lynne , Cury Philippe
Published: April 2006

The sensitivity of size-based, species-based, and trophodynamic indicators is examined for the fish community of the southern Benguela ecosystem (South Africa) through simulations of different fishing scenarios using the multispecies model OSMOSE. The simulations suggest that it may be erroneous to consider one absolute reference direction of change for any indicator because the direction of change is specific to both the multispecies assemblage and the fishing scenario considered. The analysis of species versus community indicators is helpful for understanding which processes drive the emergent properties of the ecosystem. Informative about the structure and state of the ecosystem, both types of indicators weighted by biomass or by abundance should be used to evaluate ecosystem changes. Indicators characterizing size distribution (e.g., slope of size spectrum) appear to be more helpful in distinguishing the cause of ecosystem changes than mean community indicators because their response is specific to the fishing scenario simulated (i.e., global or hake-targeting fishing). Some indicators do not seem to be sensitive to fishing pressure (slope of the diversity size spectrum) or do not vary consistently with other studies (W statistic).
Changes in seasonal energy dynamics of alewife (Alosa pseudoharengus) in Lake Michigan after invasion of dreissenid mussels
Authors: Madenjian Charles P , Pothoven Steven A , Dettmers John M , Holuszko Jeffrey D
Published: April 2006

The dreissenid mussel invasion of Lake Michigan during the 1990s has been linked to a concomitant decrease in the abundance of the amphipod Diporeia. We tracked the seasonal energy dynamics of alewife (Alosa pseudoharengus) in Lake Michigan during 20022004 and compared our findings with previously published results for years 19791981. Adult alewife energy density exhibited a pronounced seasonal cycle during both the pre-invasion and post-invasion periods, with energy density in October or November nearly twice as high as that in early summer. However, on average, adult alewife energy density was 23% lower during the post-invasion period compared with the pre-invasion period. This significant decline in energy density was attributable to decreased importance of Diporeia in adult alewife diet. In contrast, energy density of juvenile alewives did not significantly differ between the pre-invasion and post-invasion periods. To attain a weight of 8 kg by age 4, bioenergetics modeling indicated that a Chinook salmon (Oncorhynchus tshawytscha) in Lake Michigan would have to consume 22.1% more alewives during the post-invasion period compared with the pre-invasion period.
ON THE FOURIER TRANSFORMS OF THE SPINOR COMPONENTS OF HYDROGEN-LIKE ATOM RELATIVISTIC EIGENFUNCTIONS
Authors: SOLDATOV A. V. , SEKE J. , ADAM G.
Published: April 2006

An approach to calculate both the Fourier transforms of singular spinor components of relativistic eigenfunctions of hydrogen-like atoms and those of their multiple products is developed. The method simplifies calculations of the momentum representation for the eigenfunctions belonging to the discrete spectrum. Besides, it reduces the procedure of the Fourier transform for eigenfunctions of the continuous spectrum to the evaluation of only one one-dimensional integral, allowing the explicit separation of its singular part representing a generalized function. The proposed algorithm is especially convenient for large-scale numerical calculations.
A DYNAMIC STUDY OF AN ELECTRO-RHEOLOGICAL (ER) CLUTCH
Authors: TAN K. P. , STANWAY R. , BULLOUGH W. A.
Published: April 2006

Electro-rheological (ER) fluid devices are smart actuators that possess several advantages such as controllable output dynamics and fast speed of response. Due to these output capabilities, an ER clutch is studied for the possibility of actuating the robotic arm. This is achieved by laying a few objectives. The main focus of this paper is to perform model validations of an ER velocity response of this ER clutch. Next, it is aimed to determine a method for rapid energization and de-energization of the ER output velocity for delivering fast start-stop robotic motions. The third aim is to employ the trend study on the ER output velocity response in order to define suitable input parameters for optimum ER robotic performances. The final aim is to determine the reliability of the tested ER fluids shearing in the ER clutch for long-term robotic applications.
WAVE FUNCTIONS OF TIME-DEPENDENT TWO COUPLED OSCILLATORS BY LEWIS–RIESENFELD METHOD
Authors: FAN HONG-YI , JIANG ZHONG-HUA
Published: April 2006

For the two time-dependent coupled oscillators model we derive its time-dependent invariant in the context of Lewis–Riesenfeld invariant operator theory. It is based on the general solutions to the Schrödinger equation which is obtained and turns out to be the superposition of the generalized atomic coherent states in the Schwinger bosonic realization. The energy eigenvectors and eigenvalues of the corresponding time-independent Hamiltonian are also obtained as a by-product.
THE SHADOW OF LIGHT: LORENTZ INVARIANCE AND COMPLEMENTARITY PRINCIPLE IN ANOMALOUS PHOTON BEHAVIOR
Authors: CARDONE F. , MIGNANI R. , PERCONTI W. , PETRUCCI A. , SCRIMAGLIO R.
Published: April 2006

We review the results of two double-slit-like experiments in the infrared range, which evidence an anomalous behavior of photon systems under particular (energy and space) constraints. These outcomes (independently confirmed by crossing photon beam experiments in both the optical and the microwave range) apparently rule out the Copenhagen interpretation of the quantum wave, i.e. the probability wave, by admitting an interpretation in terms of the Einstein–de Broglie–Bohm hollow wave for photons. Moreover, these experiments support the interpretation of the hollow wave as a deformation of the Minkowski space-time geometry. We stress the implications of these experimental results and of their interpretation for the concept of action-at-a-distance, Einstein's relativistic correlation and Bohr's principle of complementarity,
FADING CORRECTION OF NaCl(I) TLD
Authors: ARUNKUMAR SHARMA B. , GARTIA R. K. , NABADWIP SINGH S.
Published: April 2006

The prediction of fading for the glow peaks relevant to dosimetry of iodised salt has been made using the values of the trapping parameters, namely the thermal activation energy (E), frequency factor (s) and the order of kinetic (b). This theoretical prediction has been checked with experimentally observed glow curves recorded after storage period of 2, 5, 10, 165, 375 and 790 days at room temperature (~21°C). Excellent agreement has been observed between the experimental and theoretical glow curves. This has been possible because of reliable retrieval of the trapping parameters by the use of Computerised Glow Curve Deconvolution (CGCD) as well as state-of-art of data acquisition system. The concept developed in the present paper in principle may be applied to any TLD.
LOW-LYING EXCITATIONS IN SPIN-PEIERLS SYSTEM WITH QUANTUM LATTICE DYNAMICAL EFFECT
Authors: XU JING , WANG ZHI-GUO , SHI YUN-LONG , CHEN YU-GUANG , CHEN HONG
Published: April 2006

In the continuum limit, we map a Heisenberg chain model, in which the spins are explicitly coupled to the lattice degrees of freedom, to one-dimensional quantum sine-Gorden model, and obtain the phase diagram and excitation spectrum of the system. The effect of quantum lattice fluctuation on the ground-state properties of the system is discussed in detail. The results show that a quantum phase transition from a gapless state to gapped dimerized phase occurs at nonzero value of the spin-phonon coupling. Moreover, our results indicate that the two-magnon excitation spectrum is more sensitive to the spin-phonon coupling than the one-magnon excitation spectrum.
MODELING THE EFFECTS OF CHANNEL NOISE IN NEURONS: A STUDY BASED ON DISSIPATIVE STOCHASTIC MECHANICS
Authors: GÜLER MARİFİ
Published: April 2006

A framework for modeling the effects of channel noise in neurons is proposed through an adoption of stochastic mechanics within an approach based on the coupling between collective and intrinsic states. A model of the effects in a neuron of Rose-Hindmarsh type is introduced consequently. It is found, using the model, that even though the channel noise alters the neuron's quantitative behaviour, the repertoire of basic behaviour patterns remains to be the same; and that the region of bursting activity is extended to significantly higher input current values.
CLINICAL VALIDATION OF A NOVEL SPRING LOADED TENSIONING DEVICE AND COMPUTER ASSISTED NAVIGATION
Authors: BIGNOZZI S. , ZAFFAGNINI S. , MARTELLI S. , MARCACCI M.
Published: April 2006

This study presents the validation of the tensioning device that applies a constant load to the medial and lateral compartments of knee joint separately, which can collapse or expand on each side independently, and that should be able to provide a better evaluation of ligament tension and allow the computer software to better plan the appropriate bone cuts or ligament release, and reports the first phase of the clinical validation of the tensioning device, including first qualitative comparison with standard navigated technique and consideration on the use of the device.

A randomized study, involving five experienced orthopedic surgeons with 58 complete data sets, revealed that there is no statistical difference between the gaps obtained with standard navigated technique and tensioning device in extension, while in flexion there is an average difference 1.4 mm.
INTRA-OPERATIVE TESTS ON CEMENTLESS HIP STEM MECHANICAL STABILITY
Authors: VARINI ELENA , VANDI MARCO , CRISTOFOLINI LUCA , CAPPELLO ANGELO , TONI ALDO
Published: April 2006

The aim of the present investigation was to develop a new device that enables the stability achieved by a cementless stem to be assessed intra-operatively. The angle of the stem/femur rotation under torsion and the torque are acquired and compared in real time to a pre-set stability threshold inferred from the literature. The device indicates whether the stem is stable or not. A calibration was needed to convert angular into linear shear displacements. For this reason, repeated tests in vitro were made on both cadaveric and composite femurs, chosen so as to host the same kind and size of prostheses, all implanted with different levels of press-fitting. The device was then validated. The overall accuracy, 21%, which takes into account the interfemur variability, was deemed sufficient to assess the stability.
A NEW METHOD FOR ANTHROPOMETRIC ACQUISITION OF THE UPPER EXTREMITY PARAMETERS IN ELITEMASTERSWIMMERS
Authors: ZAMPAGNI MARIA LUISA , DONA GIULIA , MOTTA MARIO , MARTELLI SANDRA , BENELLI PIERO , MARCACCI MAURILIO
Published: April 2006

The aim of the study was to test the use of a new device for anthropometric acquisition in sports applications. In particular, we used an electrogoniometer (FARO Arm) to analyze the upper extremities in 45 elderly swimmers during the 10th World Masters Championships. Conventional anthropometric parameters were measured by a conventional method (anthropometric) and also by the new method. In order to illustrate the potentiality of the new method, we also introduced a new parameter to describe the arm model in swimmers, the carrying angle.

A detailed analysis of the features and potentiality of the new method is reported in the paper. The ANOVA test did not show significant differences between the main anthropometric measurements obtained with the two methods. We concluded that the use of the FARO Arm device is effective for anthropometric measurements in sports applications, as it can reproduce conventional measurements accurately and also estimate new parameters.
A RELIABLE METHOD FOR PROTOTYPING FLEXIBLE PHYSIOLOGIC-LIKE BEHAVING LEFT VENTRICLES FOR STUDYING MITRAL VALVE SURGICAL CORRECTIONS
Authors: RASPONI MARCO , FIORE GIANFRANCO BENIAMINO , REDAELLI ALBERTO , MONTEVECCHI FRANCO MARIA , FUMERO ROBERTO
Published: April 2006

A reliable and inexpensive method was developed for the realization of flexible ventricle prototypes to be used in a pulse duplicator test circuit for cardiac valve testing, with particular emphasis on the valves in the mitral position. The peculiarity of our ventricular models is their ability to preserve a physiologic-like shape during the entire cardiac cycle. Moreover, the models take into account the function of papillary muscles, thus allowing a realistic evaluation of the whole inlet valve complex (mitral valve, chordae tendineae and papillary muscles). Ventricular sacs were designed by structural analyses, driven by a set of criteria identifying the similarity to natural ventricular conformational changes. The computationally optimized ventricle shapes were used to manufacture the mould for prototypes to be subjected to experimental validation trials. The difference between simulation-predicted and experimentally measured behaviors did not exceed 6.5%, which confirmed reliability of the developed method.
ALTERATION OF ELASTIC PROPERTIES IN CONGENITAL/INHERITED AORTIC DISEASES: MRI STUDY IN MARFAN SYNDROME AND BICUSPID AORTIC VALVE
Authors: LOVATO LUIGI , SBARZAGLIA PAOLO , MAGI SILVIA , RUSSO VINCENZO , ZANNOLI ROMANO , FATTORI ROSSELLA
Published: April 2006

Marfan Syndrome and Bicuspid Aortic Valve (BAV) are characterized by the congenital/inherited alteration of the fibrillin proteins of aortic wall extracellular matrix, with higher incidence of aortic dissection/rupture even without aortic dilation. Therefore, early identification and treatment of aortic involvement could improve prognosis. The purpose of this study was to evaluate aortic elastic properties of BAV and Marfan Syndrome patients to identify an index of early aortic involvement. Methods: A Magnetic Resonance Imaging (MRI) study was performed on 38 BAV patients, 20 Marfan patients and 14 healthy volunteers as a control group. A high-resolution gradient-echo sequence was applied in the axial plane at the level of pulmonary artery bifurcation to evaluate aortic distensibility. Results: Aortic distensibility was significantly different among the three groups (ANOVA, p = 0.0001) and was sensibly reduced in BAV (0.0056 ± 0.0048 versus 0.025 ± 0.006 control group) and Marfan (0.0085 ± 0.006 versus 0.025 ± 0.006 control group). Intraobserver and interobserver reproducibility for diastolic measurements were 1.2% and 0.4% respectively and for systolic measurements, they were 1.1% and 0.3% respectively. Conclusion: In BAV or Marfan Syndrome patients, MRI evaluation of abnormal distensibility may provide a reliable index of early aortic involvement, even before aortic dilation occurs.
ANATOMICAL INVESTIGATIONS ON THE KNEE BY MEANS OF COMPUTER-DISSECTION
Authors: MARTELLI S. , PINSKEROVA V. , VISANI A.
Published: April 2006

This paper reports an extensive analysis of the articular surfaces of the femur and the tibia in sagittal, frontal and coronal sections, obtained by digitizing the bones with a precise electrogoniometer (FARO Arm) and elaborated off-line fitting the profiles with least square curves. Within the method resolution, we show that the tibio-femoral joint can be described as consisting of two different compartments rigidly connected. The femoral medial side can be represented by an ellipsoid with its main axis in the AP direction, semi-axes equal to 30 and 23 ± 2 mm (posteriorly spherical) and circular ML section with a radius equal to 20 ± 2 mm, which articulates on a (tibial) semi-cylinder with its main axis in the AP direction and conform circular ML section (radius equal 22 ± 1.3 mm). The femoral lateral side can be represented by a ellipsoid with lower eccentricity and a shorter AP size than the medial side, semi-axes equal to 26 and 20 ± 4 mm. It has an elliptic ML section with a sloped major axis parallel to the tibial spine, which forms an angle around 160° with the lateral tibial plateau. This study integrates a previous study by two of the authors with further data on tibia and femur, explaining when the sagittal view of femoral condyles can be better fitted by ellipses than two circles and when it is equivalent. This work represents a systematic numerical study of the tibio-femoral joint in six cadaveric knees, integrates the known anatomical data and provides updated and quantitative 3D information useful for mathematical knee models, prosthesis design, further understanding of knee biomechanics and the function of knee anatomical structures.