bluuebunny/crossref_metadata_2025_split huggingface dataset:
Narrative-based learning: Possible benefits and problems
Authors: Glaser Manuela , Garsoffky Bärbel , Schwan Stephan 
Published: December 2009

Abstract
This paper addresses the issue of narrative influence on knowledge acquisition in science education. Special characteristics of narratives and of narrative processing are compared to characteristics and processing of traditional expository educational materials. This paper goes beyond the existing literature on processing of media presentations that combine narrative and educational contents. Effects of four distinctive narrative features – dramatization, emotionalization, personalization, and fictionalization – are discussed with regard to their influence on single steps in knowledge acquisition (interest, attention, elaboration, and representation) to explain the superiority of narratives over expository material found in some studies. The need for a model describing the complex relationships between the effects of the single narrative characteristics on knowledge acquisition is proposed.
Variations of Thiaminase I Activity pH Dependencies among Typical Great Lakes Forage Fish and Paenibacillus thiaminolyticus
Authors: Zajicek James L. , Brown Lisa , Brown Scott B. , Honeyfield Dale C. , Fitzsimons John D. , Tillitt Donald E. 
Published: December 2009

Abstract
The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (≥90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5–6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus–derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.
Effects of Vitamin B1 (Thiamine) Deficiency in Lake Trout Alevins and Preventive Treatments
Authors: Lee Bong-Joo , Jaroszewska Marta , Dabrowski Konrad , Czesny Sergiusz , Rinchard Jacques 
Published: December 2009

AbstractThe objectives of this study were to examine the effect of thiamine immersion of fish from a population known for compromised survival as a result of early mortality syndrome (EMS) and to investigate the cause–response relationship between thiamine concentration and lesions in tissues in swim-up-stage lake trout Salvelinus namaycush alevins. Lake trout eggs from 14 fish from Lake Michigan were artificially fertilized and the progeny divided into two groups based on the thiamine concentration (low (&lt;0.73 nmol/g) or high (&gt;0.85 nmol/g)) in the unfertilized eggs. Progeny were treated or not with a thiamine solution (2,000 mg/L for 2 h) at hatching or the swim-up stage. The survival of progeny in control groups at the swim-up stage correlated with thiamine concentration. The low thiamine-treated groups had significantly higher survival between the swim-up stage (812.0 degree-days) and 16 d after swim-up (963.3 degree-days) than the control groups; the survival of the high thiamine-treated groups did not differ between treated and control fish, regardless of the treatment at hatching and the swim-up stage. Control alevins that had low thiamine levels showed EMS, which resulted in 94.9–100% mortality 16 d after the swim-up stage. No pathological changes were observed in the brain, olfactory lobe, eye, liver, or muscle in alevins of high thiamine-treated group. Glycogen deposits in the liver of alevins from the low control group were variable, no glycogen being observed in the hepatocytes of 7 of the 24 fish. We demonstrate that thiamine treatment at swim-up enhances the survival of EMS-affected lake trout relative to treatment at hatching.
Thiaminase Activity of Crucian CarpCarassius carassiusInjected with a Bacterial Fish Pathogen,Aeromonas salmonicidasubsp. salmonicida
Authors: Wistbacka Svante , Lönnström Lars-Gustaf , Bonsdorff Erik , Bylund Göran 
Published: December 2009

AbstractDietary thiaminase I is a cause of thiamine deficiency in animals. The physiological significance of thiaminase in the organisms containing this enzyme is not known, nor are the factors causing variation in their thiaminase activity. Tests were performed to evaluate the effect a pathogen might have on thiaminase activity in fish, when analyzed both with a cosubstrate added (CATA tests) and no cosubstrate added (NCATA tests). Pyridine is known as a cosubstrate specific for thiaminase I activity that does not accelerate thiaminase II activity. Crucian carp Carassius carassius known to harbor thiaminase I activity were injected intramuscularly with live Aeromonas salmonicida, a pathogenic bacterium of fish. For comparison, other groups were injected with formalin-killed bacteria and phosphate-buffered saline, respectively; an untreated group of fish was kept as a control. The bacteria did not contain any thiaminase activity. Significantly higher thiaminase activities (CATA and NCATA) were measured in all tissues (whole blood, injected muscle, uninjected muscle, and whole fish homogenates) of fish injected with live bacteria than in the saline-injected and the uninjected groups. The thiaminase activity of blood and that in the injected, inflamed muscle tissue followed different allocation patterns in fish injected with live A. salmonicida. The amount of thiaminase I enzyme appeared to be elevated in the whole blood of injected fish in the absence of natural cosubstrate(s). The thiaminase activity of the injected, inflamed muscle suggested that both the amount of thiaminase enzyme and some yet-unidentified natural cosubstrate(s) were elevated. This suggests that in addition to the enzyme, some cosubstrate(s) of fish or pathogen origin play a regulatory role in the so-far-unknown physiological significance of thiaminase I activity in vivo. It is suggested that the health of fish should be considered when searching for factor(s) affecting its thiaminase activity.
Influence of Thiamine Deficiency on Lake Trout Larval Growth, Foraging, and Predator Avoidance
Authors: Fitzsimons John D. , Brown Scott B. , Williston Bill , Williston Georgina , Brown Lisa R. , Moore Kristin , Honeyfield Dale C. , Tillitt Donald E. 
Published: December 2009

Abstract
Diet-related thiamine deficiency increases the acute mortality, known as early mortality syndrome, of salmonines from some of the Great Lakes. The consequences of thiamine deficiency as measured at the egg stage for other important early life stage processes like growth, foraging efficiency, and predator avoidance that may also result in mortality, are unknown. Accordingly, we investigated the impacts of low thiamine on the specific growth rate (SGR) of first-feeding fry, the ability of first-feeding fry to capture Daphnia, fry emergence in the presence of a potential predator (round goby Apollina (formerly Neogobius) melanostomus), and predation by slimy sculpin Cottus cognatus. We used a combination of thiamine-deficient and thiamine-replete wild stocks of lake trout Salvelinus namaycush for this purpose. From these investigations we developed predictive relationships. Specific growth rate was related to egg thiamine concentration. From the exponential relationship, it was predicted that the threshold egg thiamine concentrations associated with 20% and 50% reductions in SGR are 8.1 and 5.1 nmol/g, respectively. The foraging rate on Daphnia was also related to egg thiamine concentration by an exponential relationship. It was predicted that the threshold concentrations associated with 20% and 50% reductions in this rate are 6.9 and 2.9 nmol/g, respectively. The presence of a round goby significantly reduced emergence success, but the level of goby predation was unrelated to egg thiamine concentration. Sculpin predation was related, although weakly, to the initial egg thiamine concentration. This research found that thiamine deficiency affected growth, foraging, and predator avoidance in lake trout fry. Growth effects resulting from thiamine deficiency may represent the most sensitive means of monitoring the impact of the secondary consequences of thiamine deficiency. Mortality associated with the combined effects of reduced growth and foraging has the potential to seriously impair lake trout recruitment.
Thiamine Deficiency Effects on the Vision and Foraging Ability of Lake Trout Fry
Authors: Carvalho Paulo S. M. , Tillitt Donald E. , Zajicek James L. , Claunch Rachel A. , Honeyfield Dale C. , Fitzsimons John D. , Brown Scott B. 
Published: December 2009

Abstract
The exact causes of the historical recruitment failures of Great Lakes lake trout Salvelinus namaycush are unknown. Thiamine deficiency has been associated with neurological abnormalities in lake trout that lead to early mortality syndrome (EMS) in salmonine swim-up fry, and EMS-related mortality at the swim-up stage is a factor that contributes to the reproductive failure of lake trout populations in the Great Lakes. The potential for adverse effects of thiamine deficiency beyond the swim-up stage is unknown. We investigated the effects of low egg thiamine on behavioral functions in young, post-swim-up lake trout fry. The behavioral endpoints included visual acuity and prey capture rates in the same groups of lake trout fry from each family. Low-thiamine eggs were produced by feeding lake trout broodstock diets entailing thiaminase activity. The thiamine content of the spawned eggs ranged from 0.3 to 26.1 nmol/g. Both visual acuity and prey capture rates were affected by the thiamine content of the eggs. The visual acuity of lake trout was severely affected by low egg thiamine, mainly at thiamine concentrations below the threshold of 0.8 nmol/g but also at higher concentrations in field-collected eggs. Feeding was also reduced with low egg thiamine content. The reduction of prey capture rates was dramatic below 0.8 nmol/g and less dramatic, but still significant, in a portion of the families with egg thiamine concentrations of less than 5.0 nmol/g from both laboratory and field samples. Approximately one-third of the latter families had reduced feeding rates. Deficits in visual acuity may be part of the mechanism leading to decreased feeding rates in these fry. The effects of low egg thiamine on both of the behavioral endpoints studied increase the risk of low recruitment rates in Great Lakes lake trout populations.
Differential resource selection within shared habitat types across spatial scales in sympatric toads
Authors: Indermaur Lukas , Winzeler Thomas , Schmidt Benedikt R. , Tockner Klement , Schaub Michael 
Published: December 2009

Differential habitat selection is a central component in the evolution of species, but it has been quantified rarely for sympatric species in relation to the multiple impacts of resources at the spatial scales at which animals operate. Our main goal was to quantify the selection of terrestrial summer habitats in a natural floodplain in Italy by two sympatric amphibians (Bufo bufo spinosus and B. viridis) as a function of habitat type, prey density, and temperature. We applied a Bayesian resource selection model at three spatial scales: (1) home range placement within the floodplain, (2) space use within 95% home ranges, and (3) space use within 50% core areas. Using these data we explored whether processes acting at large scales lead to space use patterns at small scales and whether the two species use the same habitat types in a way that would facilitate coexistence.Habitat selection was determined by habitat type, prey density, and temperature at all spatial scales, resulting in slightly higher prey density and significantly lower temperature within than outside home ranges. We conclude that amphibians perceive the distribution of habitat types as well as gradients in prey density and temperature at all spatial scales. The effects of habitat type dominated home range placement while prey density and temperature most strongly affected space use within home ranges. Our results suggest that home range placement relies on broad habitat features that indicate resource availability at small spatial scales. At the smallest spatial scale, the selection of prey and refugia is most probably facilitated due to the accumulation of environmental information as animals may sample the entire area.Both species largely preferred the same habitat types, but used them differently in relation to resources across the three spatial scales. For example, while one species used the same habitat type for foraging, the other used it for resting or both resting and foraging. Niche differentiation through differential resource selection within shared habitat types at all spatial scales may therefore facilitate the coexistence of the two species in terrestrial summer habitats.
Effectiveness of a varied assemblage of seed dispersers of a fleshy‐fruited plant
Authors: Calviño-Cancela María , Martín-Herrero Julio 
Published: December 2009

Disperser effectiveness is the number of new plants resulting from the activity of one disperser relative to other dispersers or to nondispersed seeds. Effectiveness remains largely uninvestigated due to the complexity of its measurement. We measured the effectiveness of seed dispersers (Larus michahellis, Turdus merula, and Oryctolagus cuniculus) of the shrub Corema album (Empetraceae) using a simulation model of the recruitment process that was parameterized with field data of seed dispersal, predation, and seedling emergence and validated with independent data on seedling density. The model allows tracking the fate of seeds dispersed by each animal and estimating, for the first time, disperser effectiveness as seedlings per square meter contributed by each disperser. It also allows quantifying the relative importance of different recruitment processes in determining the quantity and spatial distribution of recruitment.Larus michahellis was the most effective disperser in two of the three habitats studied, contributing 3–125 times more than the other two species, whose lower effectiveness depended mostly on deposition patterns (T. merula) or deleterious effects on seedling emergence (O. cuniculus). The dependence of the plant on each disperser differed between habitats and was the greatest in sparse scrub, where recruitment depended almost exclusively on gulls (90%). Quantity and quality of dispersal were not correlated; quality was a better predictor of disperser effectiveness. Seedling emergence was the most crucial process in determining both the spatial pattern of recruitment among microhabitats (99.8% of variance explained) and the quantity of recruitment within microhabitats (43–83%). A sensitivity analysis showed that increasing seed dispersal improved the recruitment for all dispersers when there was no competition for fruits. However, with limited fruits, increased dispersal of lower quality dispersers reduced overall recruitment.Our results show important differences in effectiveness among dispersers and illustrate the different influences of the components of effectiveness, which varied depending not only on the disperser but also on the circumstances (e.g., type of habitat).
Turning inducible defenses on and off: adaptive responses of Daphnia to a gape‐limited predator
Authors: Riessen Howard P. , Trevett-Smith Julie B. 
Published: December 2009

The use of inducible defenses is a common strategy to reduce predation while minimizing associated costs for prey. The most effective use of these defenses, however, may involve turning them on and off at different stages of ontogenetic development, with the timing dependent on prey body size and the nature of the predation environment. We develop a model based on the strike efficiency of a size‐selective predator that examines the interaction between induced morphological defenses and prey body size, including the consequences of this interaction for the optimal development of the defenses during the prey's ontogeny. We then examine this model with respect to a model system of inducible defenses: neck spine induction in the water flea Daphnia in response to predatory larvae of the phantom midge Chaoborus.In accordance with predictions of the model, the body size and timing of neck spine acquisition during Daphnia development are related to the relative sizes of the Daphnia and Chaoborus species interacting in a pond or lake. The Daphnia species examined first acquire neck spines in either the first, second, or third juvenile instar, at body lengths that range from 0.58 to 0.83 mm. Neck spine formation is initiated at larger Daphnia body sizes when these prey are subject to predation by a larger Chaoborus species (C. trivittatus) and at smaller sizes when exposed only to a smaller predator (C. americanus). Induction of these morphological defenses in Daphnia occurs later in juvenile development in the smaller of the two species we examined (D. minnehaha) than in the larger (D. pulex). Delayed acquisition of neck spines also occurs when Daphnia are exposed to predation by larger Chaoborus. The close match between model predictions and the patterns observed in nature suggests that these patterns are adaptive developmental responses to different predator environments.
Plant species richness and functional composition drive overyielding in a six‐year grassland experiment
Authors: Marquard Elisabeth , Weigelt Alexandra , Temperton Vicky M. , Roscher Christiane , Schumacher Jens , Buchmann Nina , Fischer Markus , Weisser Wolfgang W. , Schmid Bernhard 
Published: December 2009

Plant diversity has been shown to increase community biomass in experimental communities, but the mechanisms resulting in such positive biodiversity effects have remained largely unknown. We used a large‐scale six‐year biodiversity experiment near Jena, Germany, to examine how aboveground community biomass in grasslands is affected by different components of plant diversity and thereby infer the mechanisms that may underlie positive biodiversity effects. As components of diversity we defined the number of species (1–16), number of functional groups (1–4), presence of functional groups (legumes, tall herbs, small herbs, and grasses) and proportional abundance of functional groups. Using linear models, replacement series on the level of functional groups, and additive partitioning on the level of species, we explored whether the observed biodiversity effects originated from disproportionate effects of single functional groups or species or from positive interactions between them.Aboveground community biomass was positively related to the number of species measured across functional groups as well as to the number of functional groups measured across different levels of species richness. Furthermore, increasing the number of species within functional groups increased aboveground community biomass, indicating that species within functional groups were not redundant with respect to biomass production. A positive relationship between the number of functional groups and aboveground community biomass within a particular level of species richness suggested that complementarity was larger between species belonging to different rather than to the same functional groups. The presence of legumes or tall herbs had a strong positive impact on aboveground community biomass whereas the presence of small herbs or grasses had on average no significant effect. Two‐ and three‐way interactions between functional group presences were weak, suggesting that their main effects were largely additive. Replacement series analyses on the level of functional groups revealed strong transgressive overyielding and relative yields >1, indicating facilitation. On the species level, we found strong complementarity effects that increased over time while selection effects due to disproportionate contributions of particular species decreased over time. We conclude that transgressive overyielding between functional groups and species richness effects within functional groups caused the positive biodiversity effects on aboveground community biomass in our experiment.
Multi‐decade, spatially explicit population studies of canopy dynamics in Michigan old‐growth forests
Authors: Woods Kerry D. 
Published: December 2009

Established in 1935, a regular grid of 256 permanent plots includes about 20% of a 100‐ha old‐growth forest at the Dukes Research Natural Area in northern Michigan, USA. Woody stems have been re‐measured 3–7 times providing extensive quantitative records of population and community dynamics over periods of up to 72 years. Woody stems in upland hemlock–northern hardwood stands, about half of the study plots, have been mapped and individually tracked since about 1990. Remaining plots are in swampy stands dominated by Fraxinus nigra and Thuja occidentalis. Detailed, long‐term demographic data for late‐successional forests are rare in general; this data set is both of exceptional duration and unusual in spatial intensity and detail. Because sample plots are in a regular array over the stand, they can support analyses of spatiotemporal pattern at various scales. A major wind disturbance in 2002 provides a unique opportunity to compare disturbance response to baseline dynamics. Several publications based on this data set have already provided new insights into late‐successional processes, but general availability of the data set with metadata should permit a range of further comparative and integrative analyses. The study is ongoing, and new measurements will be added to the archived data set.The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at 〈http://esapubs.org/archive〉. (The accession number for each Data Paper is given directly beneath the title.)
Seasonal variation in use of winter roosts by five bat species in south-east Finland
Authors: Wermundsen Terhi , Siivonen Yrjö 
Published: December 2009

Abstract
We studied seasonal variation in the use of winter roosts by five bat species (Eptesicus nilssonii, Myotis brandtii/mystacinus, Myotis daubentonii and Plecotus auritus) in south-east Finland during the winters of 2003/2004 and 2004/2005. At the beginning of the bat hibernation season all species used higher temperatures and humidity than by the season’s end. Hibernacula were at their coldest in mid-hibernation season and became warmer towards the end of the season. However, no species hibernated in warmer locations at the end of the season than in mid-season. Results suggest that bats tend to use different strategies throughout the hibernation season, minimizing the cost of hibernation early in the season by hibernating in warmer locations and minimizing energy expenditure later in the season by hibernating in colder locations. M. brandtii/mystacinus were found in locations with stable temperature and humidity, moving to increasingly stable conditions (chambers, crevices, clusters, ceiling) towards spring. All other species hibernated in more variable microclimates throughout the hibernation season.