bluuebunny/crossref_metadata_2025_split huggingface dataset:
Managing invasive crayfish: use of X‐ray sterilisation of males
Authors: AQUILONI LAURA , BECCIOLINI ALDO , BERTI ROBERTO , PORCIANI SAURO , TRUNFIO CARMEN , GHERARDI FRANCESCA 
Published: April 2009

Summary1. In the last decade, many attempts have been made to contain the spread of the North American crayfish Procambarus clarkii, an invader of many European water bodies, but none has been successful.2. This study investigates the effects that ionising irradiation has on the reproduction of P. clarkii males by analysing the behaviour of the treated individuals, their reproductive output, the vitality and survival of their offspring and the damages induced to their gonads.3. We found that a dose of 20 Gy X‐rays did not compromise either the survival or the mating ability of males, but reduced the size of their testes and significantly altered spermatogenesis. The number of aborted eggs was larger in clutches sired by treated males, with a consequent reduction (by 43%) in the number of offspring.4. These results foster hopes in our efforts to control invasive crayfish, showing the potential effectiveness of ionising irradiation to reduce male fertility in the perspective of adopting the Sterile Male Release Technique to control P. clarkii populations.
Trans‐enamel and trans‐dentinal cytotoxic effects of a 35% H2O2 bleaching gel on cultured odontoblast cell lines after consecutive applications
Authors: Trindade F. Z. , Ribeiro A. P. D. , Sacono N. T. , Oliveira C. F. , Lessa F. C. R. , Hebling J. , Costa C. A. S. 
Published: April 2009

AbstractAim  To evaluate the trans‐enamel and trans‐dentinal cytotoxic effects of a 35% H2O2 bleaching gel on an odontoblast‐like cell lines (MDPC‐23) after consecutive applications.Methodology  Fifteen enamel/dentine discs were obtained from bovine central incisor teeth and placed individually in artificial pulp chambers. Three groups (n = 5 discs) were formed according to the following enamel treatments: G1: 35% H2O2 bleaching gel (15 min); G2: 35% H2O2 bleaching gel (15 min) + halogen light (20 s); G3: control (no treatment). After repeating the treatments three consecutive times, the extracts (culture medium + gel components that had diffused through enamel/dentine discs) in contact with the dentine were collected and applied to previously cultured MDPC‐23 cells (50 000 cells cm−2) for 24 h. Cell metabolism was evaluated by the MTT assay and data were analysed statistically (α = 5%; Kruskal–Wallis and Mann–Whitney U‐test). Cell morphology was analysed by scanning electron microscopy.Results  Cell metabolism decreased by 92.03% and 82.47% in G1 and G2 respectively. G1 and G2 differed significantly (P < 0.05) from G3. Regardless of halogen light activation, the application of the bleaching gel on the cultured odontoblast‐like cells caused significantly more severe cytotoxic effects than those observed in the nontreated control group. In addition, significant morphological cell alterations were observed in G1 and G2.Conclusion  After three consecutive applications of a 35% H2O2 bleaching agent, the diffusion of the gel components through enamel and dentine caused severe toxic effects to cultured pulp cells.
In vitro bioaccessibility of iron and zinc in fortified fruit beverages
Authors: Cilla Antonio , García‐Nebot María José , Perales Sara , Lagarda María Jesús , Barberá Reyes , Farré Rosaura 
Published: April 2009

SummaryIron and zinc bioaccessibility was estimated in the in vitro gastrointestinal digests of six different fortified fruit beverages (Fb) containing iron and/or zinc and/or skimmed milk (M). Solubility values can be used to establish trends in relative bioavailability of iron and zinc, as the first stage towards mineral bioavailability comprises solubility in the intestinal tract. FbFe, FbFeM and FbFeZnM samples showed iron bioaccessibility above 88%, differing (P < 0.05) from those of FbFeZn (53%). In turn, FbZn, FbFeZn and FbZnM samples presented higher zinc bioaccessibility (above 68%), differing (P < 0.05) from those of FbFeZnM (48%). The presence of milk‐derived caseinophosphopeptides (CPPs) formed during gastrointestinal digestion in dairy samples does not increase iron or zinc bioaccessibility in FbFeM or FbZnM vs. FbFe or FbZn, but it is hypothesised that the negative interacting effect of zinc upon iron bioaccessibility when co‐supplemented in these fruit beverages is overcome in the presence of CPPs, which favour iron solubility more than in the case of zinc.
Nutritional composition, phenolic compounds, nitrate content in eatable vegetables obtained by conventional and certified organic grown culture subject to thermal treatment
Authors: Lima Giuseppina Pace Pereira , Lopes Tássia do Vale Cardoso , Rossetto Maria Rosecler Miranda , Vianello Fabio 
Published: April 2009

SummaryThe aim of this work was to analyse some nutritional characteristics in eatable vegetables obtained by conventional and organic grown culture, focusing on vegetable parts that are generally rejected by consumers. Samples of Chinese cabbage (Brassica rapa (syn. B. campestris) spp. pekinensis)) and maize (Zea mays L.) had been analysed under raw conditions and after thermal treatment in order to test modifications in protein, lipids, carbohydrate, phenol, nitrate content and dry weight. According to our results, thermal treatment modified some characteristics. Even if for most parameters significant differences between foods obtained by the two cultivation procedures had not been observed, in organic samples a higher concentration of nitrate was found. Furthermore, domestic processing, such as cooking in boiling water, seems to have a dramatic effect on phenolic content on both kinds of food, and, as a consequence, on antioxidant activity.
The use of spinning disc reactor for processing ice cream base – effect of ageing in making model ice cream
Authors: Akhtar Mahmood , Blakemore Ian , Clayton Graham , Knapper Sarah 
Published: April 2009

SummarySpinning disc reactor (SDR) technology was tested to produce an ice cream base, which was subsequently used to make model ice cream. The ice cream base containing butterfat, lecithin, xanthan gum, sugar, skimmed milk and double cream was passed over the SDR disc spinning at 2900 rpm, heated at 80 °C and at a flow rate 6 mL s−1. The physical properties of the SDR‐processed ice cream base such as particle size and viscosity measurments, and of model ice cream including overrun, meltdown rate and sensory perception were investigated. The SDR‐processed ice cream base exhibits narrow particle‐size distribution (average particle d32 = 1.65 μm, d43 = 2.98 μm) and the viscosity was found to be similar at zero and 18 h ageing, whilst the model ice cream requires zero‐hour ageing and has a high overrun value (∼85%) and slow meltdown rate as compared with a commercial sample. The results reveal that the SDR is capable of producing a highly stable ice cream base that requires significantly less ageing than the 18 h typically associated with the traditional process of making ice cream. The SDR process provides intense mixing of ingredients which facilitates the hydration of milk proteins and stabilisers.
The effects of washing treatment on antioxidant retention in ready‐to‐use iceberg lettuce
Authors: Kenny Olive , O’Beirne David 
Published: April 2009

SummaryThe influence of washing treatment on the retention of key antioxidants in minimally processed iceberg lettuce was examined. Shredded iceberg lettuce was subjected to one of three washing treatments: a domestic wash (tap‐rinsed), immersion in distilled water (water‐dipped) or immersion in chlorinated water (chlorine‐dipped). Lettuce was subsequently packed in oriented polypropylene bags and flushed with 100% nitrogen and stored at 4 °C. Vitamin C (ascorbic acid and dehydroascorbic acid), total phenols, total antioxidants, individual phenols, individual carotenoids, colour measurements and pH were quantified on production day and throughout the storage period (8 days). Different groups of antioxidants were found to differ in their response to washing treatments. No significant (P > 0.05) effects of washing treatment were observed on total antioxidant activity, total phenolics and on the levels of individual phenolics (chicoric acid, chlorogenic acid and caffeic acid). Individual carotenoids were initially affected by washing treatment, with higher levels of lutein and beta‐carotene retained with domestic washed lettuce. Ascorbic acid was the antioxidant most affected by washing treatments with domestic washing resulting in significantly (P ≤ 0.05) higher retention of ascorbic acid throughout the storage period compared with the chlorine‐dipped lettuce.
Extraction and fractionation of lipolytic enzyme from viscera of Monterey sardine (Sardinops sagax caerulea)
Authors: Noriega‐Rodríguez Juan A. , Gámez‐Meza Nohemí , Alanis‐Villa Argentina , Medina‐Juárez Luis A. , Tejeda‐Mansir Armando , Angulo‐Guerrero Ofelia , García Hugo S. 
Published: April 2009

SummaryIn this study, lipolytic activity of a semi‐purified lipolytic enzyme (SLE) from the viscera of sardine (Sardinops sagax caerulea) was screened on the lipolysis of olive, Menhaden and sardine oil. A lipolytic enzyme was partially purified from the crude extract of sardine viscera by fractional precipitation followed by ultrafiltration (30 kDa). The main tissues found in sardine viscera were pyloric caeca (19.0% w/w), digestive tract (13.0% w/w), liver (4.8% w/w) and pancreas (1.5% w/w). Results show that pancreas had the highest lipolytic activity. There were no significant differences in lipolytic activity between pyloric caeca, intestine and liver (P < 0.05). Specific activity of the SLE increased 47.0‐fold after extraction and fractionation, with a yield of 0.34% calculated for the whole viscera weight. Lipolytic activity of SLE from sardine viscera increased threefold when sardine oil was used as substrate. The results of this study confirm the potential importance of lipases from marine sources.
Effect of moisture content, storage temperature and storage period on colour, ascorbic acid, lycopene and total flavonoids of dried tomato halves
Authors: Hossain Md. Ayub , Gottschalk Klaus 
Published: April 2009

SummaryDried tomato halves with three storage moisture contents [18%, 24% and 30%, wet basis (wb)], packed in glass jar, plastic container and polyethylene bag were stored in room and cool‐chamber environments for 5 months. During storage period average room and cool‐chamber temperatures were 20 ± 4 and 5 ± 1 °C respectively. Changes of colour, ascorbic acid, lycopene, total flavonoids and moisture contents were monitored 1‐month interval. Significantly higher losses of colour, ascorbic acid, lycopene and total flavonoids were found for room environment than those of cool chamber. A set of regression equations had been developed for colour, ascorbic acid, lycopene and total flavonoids as a function of storage time. No visible microorganisms were detected in the samples during the storage period. Dried tomato with ≤24% (wb) moisture content may be recommended to store in cool chamber (5 °C) and ≤18% (wb) to store in room environment (20 °C) both to be packed in glass jar.
Evidence that dingoes limit abundance of a mesopredator in eastern Australian forests
Authors: Johnson Chris N. , VanDerWal Jeremy 
Published: April 2009

Summary

Aggressive behaviour of top predators may have strong effects on the distribution and abundance of mesopredator species. Such interactions between predator species can reduce the intensity of predation on vulnerable prey. Suppression of mesopredators by top predators is a potentially important process that could protect small prey species from unsustainable predation.
There is some evidence that in Australia, the dingo Canis lupus suppresses populations of the red fox Vulpes vulpes. This interaction could be significant to biodiversity conservation because while dingoes have been in Australia for several thousand years and coexist with a wide range of small mammals, the fox is a recent arrival which has caused declines and extinctions, and continues to threaten many prey species.
However the strength of the effect of dingoes on foxes is unclear, and some published data have been interpreted as demonstrating no relationship between abundance of the two species. These data come from forested habitats in eastern Australia, and may suggest that negative relationships of dingoes and foxes do not occur in complex habitats.
We re‐analyse published data on fox vs. wild dog (i.e. dingoes plus, potentially, feral dogs and hybrids) abundance in eastern forests. These data reveal a triangular relationship of fox to wild dog density: when wild dogs are abundant, foxes are consistently rare, while when wild dogs are rare, foxes may be abundant but are not always so. This suggests that the abundance of wild dogs sets an upper limit on the abundance of foxes, but does not fully determine fox abundance.
Standard regression and correlation methods are not appropriate for analysing such triangular relationships. We apply two statistical methods that can be used to characterize the edges of data distributions, and use these to demonstrate a negative relationship of maximum fox abundance to the abundance of wild dogs.
Synthesis and applications. Our analysis adds to evidence that dingoes may have negative effects on red foxes in a wide range of habitats, and therefore, that dingoes may be significant to conservation of mammal biodiversity in Australia. It also illustrates problems and solutions in the statistical analysis of abundance of one species as a function of the abundance of another species with which it has a strong interaction.
Strong mixture effects among four species in fertilized agricultural grassland led to persistent and consistent transgressive overyielding
Authors: Nyfeler Daniel , Huguenin‐Elie Olivier , Suter Matthias , Frossard Emmanuel , Connolly John , Lüscher Andreas 
Published: April 2009

SummaryIncreasing plant species richness often increases biomass production in nutrient‐poor semi‐natural grasslands. If such positive diversity–productivity effects also apply to nutrient‐rich agricultural grasslands, mixtures could improve resource‐use efficiency in the vast area used for forage production. We therefore quantified the diversity–productivity effects in nutrient‐rich agricultural grasslands using four‐species grass–legume mixtures.The sown overall density and species proportions ofLolium perenne,Dactylis glomerata,Trifolium pratenseandTrifolium repenswere varied in a 3‐year field experiment to investigate the effects of species richness (1, 2, 4 species) and species proportion (0, 3, 10, 25, 40, 50, 70, 90, 100% sowing proportion) on productivity under a nitrogen fertilization of 50, 150 or 450 kg N ha−1 year−1.The four‐species mixtures reached up to twice the yield of the average of the four species’ monocultures (overyielding up to 106%), predominantly due to combining grass and legume species. Mixtures were up to 57% more productive than the most productive monoculture (transgressive overyielding). Both these diversity–productivity effects appeared across a broad range of species proportions and persisted at the two lower levels of N fertilization for 3 years.Mixtures fertilized with 50 kg N ha−1 year−1produced yields comparable to grass monocultures fertilized with 450 kg N ha−1 year−1, if the legume proportion was about 50 to 70%. Diversity–productivity effects were reduced at the highest level of N fertilization, where they virtually disappeared in the third year. Increased N fertilization also accelerated the observed general trend towardsD. glomeratadominated and legume‐poor swards.Synthesis and applications. Diversity–productivity effects led to consistent transgressive overyielding in intensively managed grasslands, suggesting a highly increased resource‐use efficiency in mixtures. Performance better than monocultures can be achieved with grass–legume mixtures that have a low number of species, across a wide range of species proportions and in nutrient‐rich conditions. Processes such as niche complementarity and positive interspecific interactions leading to diversity effects proved to be highly relevant and widely applicable for intensive forage production. Such diversity–productivity effects could allow reduced inputs of N fertilizer without loss of productivity in different grassland production systems.
Contrasting patterns and mechanisms of spatial turnover for native and exotic freshwater fish in Europe
Authors: Leprieur Fabien , Olden Julian D. , Lek Sovan , Brosse Sébastien 
Published: April 2009

AbstractAim  We compare the distribution patterns of native and exotic freshwater fish in Europe, and test whether the same mechanisms (environmental filtering and/or dispersal limitation) govern patterns of decrease in similarity of native and exotic species composition over geographical distance (spatial species turnover).Locations  Major river basins of Europe.Methods  Data related to geography, habitat diversity, regional climate and species composition of native and exotic freshwater fish were collated for 26 major European river basins. We explored the degree of nestedness in native and exotic species composition, and quantified compositional similarity between river basins according to the beta‐sim (independent of richness gradient) and Jaccard (dependent of richness gradient) indices of similarity. Multiple regression on distance matrices and variation‐partitioning approaches were used to quantify the relative roles of environmental filtering and dispersal limitation in shaping patterns of decreasing compositional similarity over geographical distance.Results  Native and exotic species exhibited significant nested patterns of species composition, indicating that differences in fish species composition between river basins are primarily the result of species loss, rather than species replacement. Both native and exotic compositional similarity decreased significantly with increasing geographical distance between river basins. However, gradual changes in species composition with geographical distance were found only for exotic species. In addition, exotic species displayed a higher rate of similarity decay (higher species turnover rate) with geographical distance, compared with native species. Lastly, the majority of explained variation in exotic compositional similarity was uniquely related to geography, whereas native compositional similarity was either uniquely explained by geography or jointly explained by environment and geography.Main conclusions  Our study suggests that large‐scale patterns of spatial turnover for exotic freshwater fish in Europe are generated by human‐mediated dispersal limitation, whereas patterns of spatial turnover for native fish result from both dispersal limitation relative to historical events (isolation by mountain ranges, glacial history) and environmental filtering.
Effects of habitat history and extinction selectivity on species‐richness patterns of an island land snail fauna
Authors: Chiba Satoshi , Okochi Isamu , Ohbayashi Takashi , Miura Daichi , Mori Hideaki , Kimura Kazuki , Wada Shinichiro 
Published: April 2009

AbstractAim Local‐scale diversity patterns are not necessarily regulated by contemporary processes, but may be the result of historical events such as habitat changes and selective extinctions that occurred in the past. We test this hypothesis by examining species‐richness patterns of the land snail fauna on an oceanic island where forest was once destroyed but subsequently recovered.Location Hahajima Island of the Ogasawara Islands in the western Pacific.Methods Species richness of land snails was examined in 217 0.25 × 0.25 km squares during 1990–91 and 2005–07. Associations of species richness with elevation, current habitat quality (proportion of habitat composed of indigenous trees and uncultivated areas), number of alien snail species, and proportion of forest loss before 1945 in each area were examined using a randomization test and simultaneous autoregressive (SAR) models. Extinctions in each area and on the entire island were detected by comparing 2005–07 records with 1990–91 records and previously published records from surveys in 1987–91 and 1901–07. The association of species extinction with snail ecotype and the above environmental factors was examined using a spatial generalized linear mixed model (GLMM).Results The level of habitat loss before 1945 explained the greatest proportion of variation in the geographical patterns of species richness. Current species richness was positively correlated with elevation in the arboreal species, whereas it was negatively correlated with elevation in the ground‐dwelling species. However, no or a positive correlation was found between elevation and richness of the ground‐dwelling species in 1987–91. The change of the association with elevation in the ground‐dwelling species was caused by greater recent extinction at higher elevation, possibly as a result of predation by malacophagous flatworms. In contrast, very minor extinction levels have occurred in arboreal species since 1987–91, and their original patterns have remained unaltered, mainly because flatworms do not climb trees.Main conclusions The species‐richness patterns of the land snails on Hahajima Island are mosaics shaped by extinction resulting from habitat loss more than 60 years ago, recent selective extinction, and original faunal patterns. The effects of habitat destruction have remained long after habitat recovery. Different factors have operated during different periods and at different time‐scales. These findings suggest that historical processes should be taken into account when considering local‐scale diversity patterns.
Mobile game‐based learning in secondary education: engagement, motivation and learning in a mobile city game
Authors: Huizenga J. , Admiraal W. , Akkerman S. , Dam G. ten 
Published: April 2009

AbstractUsing mobile games in education combines situated and active learning with fun in a potentially excellent manner. The effects of a mobile city game called Frequency 1550, which was developed by The Waag Society to help pupils in their first year of secondary education playfully acquire historical knowledge of medieval Amsterdam, were investigated in terms of pupil engagement in the game, historical knowledge, and motivation for History in general and the topic of the Middle Ages in particular. A quasi‐experimental design was used with 458 pupils from 20 classes from five schools. The pupils in 10 of the classes played the mobile history game whereas the pupils in the other 10 classes received a regular, project‐based lesson series. The results showed those pupils who played the game to be engaged and to gain significantly more knowledge about medieval Amsterdam than those pupils who received regular project‐based instruction. No significant differences were found between the two groups with respect to motivation for History or the Middle Ages. The impact of location‐based technology and game‐based learning on pupil knowledge and motivation are discussed along with suggestions for future research.