bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative evaluation of the degree of pegylation of poly(lactic-co-glycolic acid) nanoparticles in enhancing central nervous system delivery of loperamide
Authors: Kirby Brian P , Pabari Ritesh , Chen Chi-Nan , Al Baharna Marwa , Walsh Jeremy , Ramtoola Zebunnissa 
Published: August 2013

Abstract

Objectives
In this study, we examined the relative cellular uptake of nanoparticles (NPs) formulated using poly(lactic-co-glycolic acid) (PLGA) polymers with increasing degree of pegylation (PLGA-PEG) and their potential to deliver loperamide to the brain of a mouse.

Method
NPs containing coumarin-6 or loperamide HCl were formulated using PLGA and PLGA-PEG, with PEG content of 5–15%, by the solvent evaporation method. NPs were characterised for size, surface charge, morphology, encapsulation efficiency and drug release. Cellular uptake of coumarin-6 NPs was examined in Caco-2 monolayers using confocal microscopy and central nervous system (CNS) delivery of loperamide HCl from the NPs was examined following intranasal administration in a mouse model.

Key findings
No difference in NP characteristics was observed, irrespective of degree of pegylation, except for the surface charge which increased with increasing PEG content. PLGA-PEG NPs were found to have increased cellular uptake in comparison to PLGA NPs. Interestingly, this pattern was reflected in the CNS delivery of loperamide HCl in the mouse model.

Conclusion
The results from this study show that PLGA-PEG NPs have the potential to act as carriers for the noninvasive administration of therapeutic agents to the brain and possibly across other physiological barriers.
Effect of different levels of black cumin (Nigella sativa L.) on performance, intestinal Escherichia coli colonization and jejunal morphology in laying hens
Authors: Boka J. , Mahdavi A. H. , Samie A. H. , Jahanian R. 
Published: August 2013

SummaryThis study was conducted to investigate the effects of different levels of black cumin seeds (Nigella sativa L.) on performance, intestinal Escherichia coli count and morphology of jejunal epithelial cells in laying hens. A total of 100 Leghorn laying hens (Hy‐Line W‐36) of 49 weeks old were randomly distributed among five cage replicates of five birds each. Experimental diets consisted of different levels (0%, 1%, 2% and 3% of diet) of dietary black cumin inclusion. The experimental period lasted for a total of 10 weeks, and egg quality indexes and laying hens' performance were measured as two 35‐day trial periods. At the final day, two hens per replicate were slaughtered to investigate the influence of dietary treatments on intestinal E. coli colonization and morphology of jejunal cells. Although dietary black cumin in all supplementation levels decreased (p < 0.05) the enumeration of ileal E. coli, the morphological and histological alterations in small intestine such as enhancement of villus height to crypt depth ratio, increased goblet cell numbers and proliferation of lamina propria lymphatic follicles were observed after dietary supplementation with at least 2% black cumin. Dietary treatments decreased (p < 0.05) the concentration of serum cholesterol and triglycerides and increased (p < 0.05) serum HDL concentration and relative weight of pancreas; however, the egg yolk cholesterol was not influenced by dietary treatments. In addition, dietary supplementation with black cumin improved (p < 0.05) eggshell quality and Haugh unit. The best feed conversion ratio was obtained when diets were supplemented with 2% black cumin. This improvement was due to the increase (p < 0.05) in egg mass and contemporaneous decrease (p < 0.01) in feed consumption. The present results indicated that regardless of supplementation level, dietary inclusion of black cumin decreased E. coli enumeration in ileal digesta and improved serum lipid profile and eggshell quality, whereas the best intestinal health indices and haying hens' performance were obtained by at least 2% black cumin seeds.
The Influence of Lecithin from Different Sources on Crystallization and Physical Properties of Nontrans fat
Authors: Lončarević Ivana , Pajin Biljana , Omorjan Radovan , Torbica Aleksandra , Zarić Danica , Maksimović Jovana , Švarc Gajić Jaroslava 
Published: August 2013

AbstractCrystallization and physical properties of nontrans vegetable fat with the addition of soybean, sunflower and rapeseed lecithin were investigated in this paper. NMR technique was used for measuring the solid fat content of fats at different temperatures, as well as for crystallization rate under static conditions. Also, the possibility of applying Gompertz function to define kinetics of crystallization was investigated. Rheological and textural properties were determined using the rotational viscometer and texture analyzer, whereas thermal properties were obtained by differential scanning calorimetry (DSC). The addition of lecithin from different sources does not affect the crystallization characteristics of nontrans edible fat, whereas rheological and textural tests confirmed that the addition of lecithin in excess increases the complexity of the system. DSC measurement confirmed the presence of three fractions in fat with different melting properties. The addition of lecithin from different sources has a significant effect on energy required for melting and some effect on other thermal properties of nontrans edible fat.Practical ApplicationsSoybean seeds are the main source of lecithin in confectionery industry in Serbia and elsewhere. The extensive production of sunflower and rapeseed oil opens the possibility of using lecithin from these sources as an alternative. Also, the development of functional foods dictates the use of edible fats with no undesirable trans fatty acids, obtained by fractionation and transesterification instead of common hydrogenation process. The impact of lecithin from different sources on crystallization and physical properties of pure nontrans fat is the base for this research. The lecithin obtained from sunflower and rapeseed should be further examined in different confectionery products with continuous fat phase, and should appropriate emulsifying properties are achieved, they could be used in the confectionery production as well.
Effects of land‐use changes on plant functional and taxonomic diversity along a productivity gradient in wet meadows
Authors: Janeček Š. , de Bello F. , Horník J. , Bartoš M. , Černý T. , Doležal J. , Dvorský M. , Fajmon K. , Janečková P. , Jiráská Š. , Mudrák O. , Klimešová J. 
Published: August 2013

AbstractQuestionsTo what extent do changes in management (abandonment and fertilization) affect plant functional and taxonomic diversity in wet meadow communities? To what extent do the changes in functional and taxonomic diversity depend on site productivity?LocationŽelezné hory Mts., Czech Republic.MethodsExperimental plots were established on 21 wet meadows differing in productivity and species composition. In each meadow, in 2007, four 1 × 1 m plots were established, representing a full factorial design with abandonment and fertilization as the factors. In each plot, the number of species present was recorded in 100 subplots (0.1 × 0.1 m) in the years 2007, 2009 and 2011. Different indicators of functional diversity (functional richness, functional evenness, and Rao′s quadratic entropy) were calculated using five functional traits (SLA, LDMC, seed mass, plant height and clonality). Both abundance‐weighted and non‐weighted diversity indices were calculated. Randomization tests (conducted with PERMANOVA) were used to assess the effect of site productivity and management on both α‐ and β‐diversity components.ResultsMeadows along the productivity gradient differed in functional and taxonomic diversity. Both abandonment and fertilization decreased taxonomic diversity. Whereas fertilization decreased functional richness and Rao′s quadratic entropy, abandonment decreased functional evenness. The changes in both taxonomic and functional diversity caused by abandonment and fertilization occurred faster in more productive meadows.ConclusionsThe increased dominance of tall species with abandonment and fertilization, followed by the loss of species and the decrease in various indicators of functional diversity, suggest that increased competition for light resulted in increased trait convergence among co‐existing species. In addition, many processes occurring after abandonment and fertilization depend on meadow productivity. Results suggest that abundance‐ and non‐abundance‐weighted diversity indices give complementary insights on community structure. These results imply that changes are needed in current meadow management and conservation.
Does trait conservatism guarantee that indicators of phylogenetic community structure will reveal niche‐based assembly processes along stress gradients?
Authors: Mason Norman W.H. , Pavoine S. 
Published: August 2013

AbstractQuestionIs the strength of phylogenetic trait conservatism in the species pool reflected in the ability of α‐ and β‐scale phylogenetic diversity indicators to detect niche‐based assembly processes along stress gradients?MethodsWe used a simple community assembly model to explore the power of indicators of phylogenetic community structure to detect assembly processes. The model assumes that with declining stress the influence of niche complementarity on species fitness increases, while that of environmental filtering decreases. We separately incorporated two trait‐independent stochastic processes – mass and priority effects – in simulating species occurrences and abundances along a hypothetical stress gradient. We measured power for α‐ and β‐scale indices of phylogenetic diversity (PD) as the proportion of simulations yielding a significant correlation between these indices and the community position along the stress gradient. For α‐scale indices, we ran simulations where species richness was constant along the gradient, or either increased, decreased or varied randomly with declining stress. We used four models of trait evolution, differing in the degree of phylogenetic trait conservatism, to examine how variation in the influence of phylogeny on trait variation impacted the power of PD indices.ResultsNone of the PD indices gave high power to detect assembly processes for either the mass effects or priority effects model, even when trait variation was strongly conserved. Those measures of α PD that gave moderate power in the priority‐effects model with strong trait conservatism were greatly affected by variation in species richness. Consequently, none of the indices examined met the necessary selection criteria. Additional analyses revealed that trait conservatism at the species pool level was poorly maintained at the meta‐community scale, with phylogenetically‐determined species composition having only moderate power to detect functionally‐determined species turnover. This lack of a strong phylogenetic signal in trait variation at the meta‐community scale is the most likely explanation for the poor ability of PD indices to detect assembly processes in our study.ConclusionPhylogenetic diversity indices seem to have limited ability to detect trait‐based assembly processes along ecological gradients, even when trait conservatism at the species pool level is strong. Consequently, PD is unlikely to provide a means of avoiding the tough decisions around which traits are most relevant for assembly processes. Rather, our findings emphasize the need to collect relevant functional trait data to understand the mechanisms controlling community assembly.
Correlations between phylogenetic and functional diversity: mathematical artefacts or true ecological and evolutionary processes?
Authors: Pavoine Sandrine , Gasc Amandine , Bonsall Michael B. , Mason Norman W.H. 
Published: August 2013

AbstractQuestionsIs phylogenetic diversity (PD) an accurate surrogate for functional diversity (FD)? How areFD:PDcorrelations affected by the diversity index used, covarying factors and/or the strength of the phylogenetic signal in ecological traits?LocationField study, coastal marsh plain Mekhada, Algeria, complemented by simulated data.MethodsFDandPDindices might correlate simply because variation in species richness and evenness (referred to as co‐factors) influences bothFDandPDvalues. We partitionFDandPDindices into components influenced by species richness, evenness and species' (functional and phylogenetic) characteristics. When a simple partition was not found, comparison to null models was used to remove the effects of co‐factors. We examined correlations between tenFDandPDindices, among which several were shown to be connected using our mathematical partitioning approach and several were transformed by comparison with null models to control for effects of co‐factors. In doing this,FDvalues were calculated using simulated trait values with varying phylogenetic signal. We then selected a subset of complementaryFDandPDindices in exploring the influence of environmental variables on diversity across 75 plant assemblages in Mekhada.ResultsAltogether, mathematical partitioning and the comparison to null models successfully removed the effects of co‐factors when comparingFDandPD. For all indices affected by species richness,FD:PDcorrelations approached 1, irrespective of the trait evolution model used. In contrast, simulations showed thatFD:PDcorrelations measured with indices unaffected by co‐factors decreased when the phylogenetic signal in traits decreased. Applied to plant assemblages in Mekhada, complementary diversity indices showed that, despite significant (but moderate)FD:PDcorrelation,FDbut notPDwas significantly correlated with the main stress gradient (salinity).ConclusionsFrom both our simulations and analysis of plant community diversity,PDwas a poor surrogate forFD. In Mekhada,PDwas also less correlated with environmental variables thanFD. Species richness was found to be a better surrogate forFDthanPDin identifying the ecological processes that distribute species along the salinity gradient.
Landscape‐level variability in historical disturbance in primary Picea abies mountain forests of the Eastern Carpathians, Romania
Authors: Svoboda Miroslav , Janda Pavel , Bače Radek , Fraver Shawn , Nagel Thomas A. , Rejzek Jan , Mikoláš Martin , Douda Jan , Boublík Karel , Šamonil Pavel , Čada Vojtěch , Trotsiuk Volodymyr , Teodosiu Marius , Bouriaud Olivier , Biriş Adrian I. , Sýkora Ondřej , Uzel Petr , Zelenka Jiří , Sedlák Vít , Lehejček Jiří 
Published: August 2013

AbstractQuestionsHow have the historical frequency and severity of natural disturbances in primary Picea abies forests varied at the forest stand and landscape level during recent centuries? Is there a relationship between physiographic attributes and historical patterns of disturbance severity in this system?LocationPrimary P. abies forests of the Eastern Carpathian Mountains, Romania; a region thought to hold the largest concentration of primary P. abies forests in Europe's temperate zone.MethodsWe used dendrochronological methods applied to many plots over a large area (132 plots representing six stands in two landscapes), thereby providing information at both stand and landscape levels. Evidence of past canopy disturbance was derived from two patterns of radial growth: (1) abrupt, sustained increases in growth (releases) and (2) rapid early growth rates (gap recruitment). These methods were augmented with non‐metric multidimensional scaling to facilitate the interpretation of factors influencing past disturbance.ResultsOf the two growth pattern criteria used to assess past disturbance, gap recruitment was the most common, representing 80% of disturbance evidence overall. Disturbance severities varied over the landscape, including stand‐replacing events, as well as low‐ and intermediate‐severity disturbances. More than half of the study plots experienced extreme‐severity disturbances at the plot level, although they were not always synchronized across stands and landscapes. Plots indicating high‐severity disturbances were often spatially clustered (indicating disturbances up to 20 ha), while this tendency was less clear for low‐ and moderate‐severity disturbances. Physiographic attributes such as altitude and land form were only weakly correlated with disturbance severity. Historical documents suggest windstorms as the primary disturbance agent, while the role of bark beetles (Ips typographus) remains unclear.ConclusionsThe historical disturbance regime revealed in this multi‐scale study is characterized by considerable spatial and temporal heterogeneity, which could be seen among plots within stands, among stands within landscapes and between the two landscapes. When the disturbance regime was evaluated at these larger scales, the entire range of disturbance severity was revealed within this landscape.
Interactive Effects of Vitamin C and E Supplementation on Growth, Fatty Acid Composition, and Lipid Peroxidation of Sea Cucumber, Apostichopus japonicus, Fed with Dietary Oxidized Fish Oil
Authors: Gao Jian , Koshio Shunsuke , Ishikawa Manabu , Yokoyama Saichiro , Nose Daisuke , Ren Tongjun 
Published: August 2013

AbstractA feeding trial was conducted to determine the interactive effects of vitamin C (ascorbic acid, AsA) and E (α‐tocopherol, α‐Toc) supplementation with dietary oxidized fish oil (OFO) on the growth performance, whole‐body AsA, and α‐Toc concentrations and fatty acid composition of juvenile sea cucumber. In a 9‐wk feeding trial, juveniles (average weight: 0.6 ± 0.1 g) were cultured in twenty‐four 50‐L tanks (30 juveniles per tank) in triplicate, and fed with eight test diets containing two levels of OFO (8.9 and 156.9 meq/kg) with varying levels of vitamin C (500 and 1000 mg AsA equivalents/kg diet) and E (100 and 200 mg α‐Toc equivalents/kg diet) supplementation, respectively. Body weight gain of sea cucumber was significantly reduced by dietary OFO, while mortality and whole‐body thiobarbituric acid‐reactive substances value were increased significantly. Increasing dietary vitamin C and E levels significantly increased whole‐body α‐Toc and AsA concentrations, respectively. A high level of vitamin E combined with OFO led to consumption of AsA. Even with supplementation of a large dose of vitamin C and/or E in diets, growth performance could not be improved, probably due to the high levels of vitamins in the control diets.
Phenotypic and Genetic Variation in Two North American Arctic Charr, Salvelinus alpinus, Stocks Cultured in a Recirculating Aquaculture System
Authors: Wolters William R. , Burr Gary S. , Palti Yniv , Vallejo Roger L. 
Published: August 2013

AbstractArctic charr, Salvelinus alpinus, were obtained as eggs from two North American sources, an eastern (Fraser River, Canada) and a western (Bristol Bay, Alaska, USA) stock. Fish were pit tagged (eastern , western ) and stocked communally into three replicated 7‐m3 tanks at a density of 7.6 ± 1.2 kg/m3. Each tank was supplied with 2 ppt salinity water from a recirculating biological filtration system. Fish were fed a commercial diet (48%P, 20%F) from automatic feeders. Fish were harvested approximately 24 mo after hatching at a final tank density of 56.2 ± 1.3 kg/m3. Mean daily water temperature was 10.4 C with a range of 5.9–12.6 C and mean dissolved oxygen was 12.6 mg/L with a range of 9.7 (91% of saturation) to 17.8 mg/L (149% of saturation). Individual fish were evaluated for total, carcass, and fillet weight, sex, stage of sexual maturity, fillet fat, fillet color, and gonad weight. The western stock fish grew faster and were significantly larger () (P < 0.0001) than the eastern stock (). Heritabilities were low for all traits and ranged from 0.08 ± 0.06 to 0.28 ± 0.09. Genetic correlations for body size traits were highly positive and significant (0.99–1.00). Genetic correlations of fillet color and body size traits were positive, but not significant. Genetic correlations of fillet fat with body size traits were negative, but not significant. Genetic correlation of fillet fat and fillet color was positive and significant (0.55 ± 0.27). Random genetic variation was assessed from microsatellite variability on 30 fish from each stock (eastern and western) and 32 fish from a third commercial source of unknown origin for comparison. The amount of variation detected in the western stock was higher than the eastern and commercial stocks. The eastern stock was composed of an admixture of two sources, the commercial stock was composed by three different sources, and the western stock was composed by three to four source populations. Data will be used to calculate breeding values on a separate group of captive sibling adult broodfish and a line selected for carcass weight and maturity at 3 yr will be developed.
Costs of Winter Feeding of Channel‐blue (♀ Ictalurus punctatus × ♂ Ictalurus furcatus) Hybrid Catfish
Authors: Kumar Ganesh , Engle Carole R. 
Published: August 2013

AbstractPrevious research has shown that winter feeding is beneficial in preventing weight loss and maintaining catfish health. Although several studies suggest the importance of winter feeding of channel catfish, Ictalurus punctatus, less is known about optimal winter feeding strategies for channel‐blue hybrid catfish (♀ Ictalurus punctatus × ♂ Ictalurus furcatus). Three winter feeding treatments (unfed, fed daily, and fed based on temperature‐threshold feeding) were each assigned randomly to four replicate 0.10‐ha earthen ponds. All ponds were stocked with large channel‐blue hybrid catfish (0.96 ± 0.40 kg) at the rate of 3409 kg/ha and fed using a slow‐sink 28% protein pelleted feed. The two feeding treatments showed significantly greater mean weight at harvest, gross yield, and growth rates than the unfed fish after the 113‐d winter trial. Partial budget analysis indicated that additional costs incurred from the additional feed, fuel, and labor costs over the winter in fed treatments offset the additional revenue from daily winter feeding. However, in the temperature‐threshold feeding treatment, additional costs were similar to additional revenues when 10‐yr average prices were used. Results were sensitive to feed prices and spring catfish prices with positive net benefits from winter feeding at fish prices above $1.58/kg and feed prices below $0.286/kg.
Resting Egg Production and Fatty Acid Enhancement in the Waterflea, Ceriodaphnia quadrangula, by Using Combination of Light Regime and Food
Authors: Farhadian Omidvar , Taghavi Delaram , Soofiani Nasrollah Mahboobi , Keivany Yazdan 
Published: August 2013

AbstractCombined effects of different light regimes, 6L:6D and 12L:12D (hours light : hours dark, L:D) and algal foods of Scenedesmus quadricauda (S) and Chlorella vulgaris (C) on ephippia production and fatty acid (FA) profile of Ceriodaphnia quadrangula were investigated. The highest resting egg production, density, and specific growth rate were obtained with 6L:6D+S; followed by 12L:12D+S treatment. The C16:0 varied from 16.2 to 22.16 mg/g dry weight (d.w.); C18:1n−9 from 11.03 to 14.94 mg/g d.w; C18:2n−6 from 9.79 to 20.24 mg/g d.w; and C18:3n−3 from 6.98 to 16.02 mg/g d.w. The amounts of C20:4n−6 (4.36 mg/g d.w) and C20:5n−3 (3.35 mg/g d.w) at 6L:6D+S were highest compared to other treatments. The maximum saturated fatty acids and monounsaturated fatty acids were obtained at 6L:6D+C while maximum polyunsaturated fatty acids observed at 6L:6D+S and 12L:12D+C. The resting egg production and FAs profile could be improved when the frequency of changes from light to dark were increased. Our findings also indicate a significant increase in the quantity of C18:3n−3 in C. quadrangula populations during resting egg formation, hence, implying that manipulation of light regime and algal food can improve performance of C. quadrangula as a live food in aquaculture industries, especially for larval feeding.