Feeding ecology and interactions of invasive vendace and DR whitefish in the Pasvik watercourse

Introductions and invasions of species outside their natural range can have devastating effects on the native species and be a major driver of biodiversity change. When the zooplanktivorous vendace invaded the Pasvik watercourse in the 1990s, it quickly took over the ecological role of the native DR whitefish. In the upper part of the watercourse, DR whitefish was displaced from the pelagic habitat and food resources, whereas in the lower part, the invasion developed at a slower rate and the two fish species have been able to coexist. Heavy predation from vendace led to the disappearance of the biggest cladoceran species in the watercourse and the remaining species have shifted towards smaller body sizes. The present study explores how the zooplankton community differ in density and composition and how the diet utilization and resource partitioning of pelagic vendace and DR whitefish vary among three contrasting lake sites; Ruskebukta and Tjærebukta in the upper and Skrukkebukta in the lower part of the watercourse, over four different study years. Further, the study explores whether inter-annual temperature variations can explain the variations in body size of Bosmina spp. and Daphnia sp. Samples were collected in September in the four study years in the pelagic zone of the three localities. Stomach content from all vendace and DR whitefish individuals were analyzed and zooplankton species were identified and measured in both the stomach and the environment samples. A key finding was that the zooplankton communities and the fish diets in Tjærebukta and Skrukkebukta were similar to each other in all study years, as opposed to Ruskebukta, where Bosmina spp. was almost depleted from the locality and DR whitefish was chiefly displaced from the pelagic zone and its resources. The body sizes of Bosmina spp. and Daphnia sp. could not be correlated to inter-annual temperature variations. The study revealed strong zooplankton predation and interspecific competition following the vendace invasion, but the impacts largely varied between sites. In the upper localities, strong interspecific competition for a down-grazed zooplankton resource has forced the DR whitefish in Ruskebukta to change its realized niche to benthic invertebrates and surface insects, whereas in Tjærebukta, DR whitefish has stayed in its original niche but its population densities have been strongly reduced. In Skrukkebukta, a lower density of vendace has led to a lower predation pressure on Bosmina spp. and lower interspecific competition, enabling coexistence of the two pelagic fish competitors. In conclusion, the vendace invasion has had major impacts on the pelagic compartment of the ecosystems in the Pasvik watercourse, where both the DR whitefish and the prey community has been negatively affected

Formation initiale : quels objectifs ?

Après avoir souligné la dimension transdisciplinaire de l’ouverture internationale, l’auteur dresse l’inventaire des compétences à développer, indique les relais à établir avec la formation continue et les innovations à introduire dans les programmes, les structures et la gestion des moyens. Le faible impact des programmes de mobilité d’étudiants sur les modèles de formation prouve l’intérêt de développer les coopérations internationales pour la recherche dans le domaine de la formation des enseignants

Norvège. Le consensus au cœur des réformes

Dans tous les pays, l’éducation est issue d’une culture nationale et témoigne des valeurs constitutives de la société qui la porte. Le système éducatif, sa structure et son mode de financement, le contenu de l’enseignement et les méthodes de travail, en sont des témoins caractéristiques. Dans le même temps, l’éducation actuelle ne reste pas enfermée à l’intérieur de l’État-nation. Le développement rapide des nouvelles technologies d’information et de communication, la globalisation de l’écono..

The Oslo Health Study: A Dietary Index Estimating Frequent Intake of Soft Drinks and Rare Intake of Fruit and Vegetables Is Negatively Associated with Bone Mineral Density

Background. Since nutritional factors may affect bone mineral density (BMD), we have investigated whether BMD is associated with an index estimating the intake of soft drinks, fruits, and vegetables. Methods. BMD was measured in distal forearm in a subsample of the population-based Oslo Health Study. 2126 subjects had both valid BMD measurements and answered all the questions required for calculating a Dietary Index = the sum of intake estimates of colas and non-cola beverages divided by the sum of intake estimates of fruits and vegetables. We did linear regression analyses to study whether the Dietary Index and the single food items included in the index were associated with BMD. Results. There was a consistent negative association between the Dietary Index and forearm BMD. Among the single index components, colas and non-cola soft drinks were negatively associated with BMD. The negative association between the Dietary Index and BMD prevailed after adjusting for gender, age, and body mass index, length of education, smoking, alcohol intake, and physical activity. Conclusion. An index reflecting frequent intake of soft drinks and rare intake of fruit and vegetables was inversely related to distal forearm bone mineral density

Variations in Postprandial Blood Glucose Responses and Satiety after Intake of Three Types of Bread

Background. The magnitude and duration of postprandial blood glucose (PPG) elevations are important risk factors of diabetes and coronary heart diseases. Aim. To study PPG after ingestion of breads with and without pea fibre and rapeseed oil. Methods. After fasting overnight, 10 Pakistani immigrant women participated in three experiments having a crossover design and involving ingestion of various types of bread: regular coarse bread or fibre enriched-bread with two levels of rapeseed oil, all providing 25 g available carbohydrates (CHO). Blood glucose and satiety were determined before the meal and every 15 min over the next 2 hours. Results. Intake of an amount of pea fibre-enriched bread containing 25 g CHO attenuated, the postprandial peak glucose value, the incremental area under the glucose versus time curve during 15 to 75 min, and the glycemic profile, and increased duration of satiety (P < .05), as compared with intake of regular bread with 25 g carbohydrate. Conclusion. Pea fibre-enriched breads can reduce PPG and prolong satiety

Expression of circadian clock genes and proteins in urothelial cancer is related to cancer-associated genes

Background: The purpose of this study was to evaluate invasive and metastatic potential of urothelial cancer by investigating differential expression of various clock genes/proteins participating in the 24 h circadian rhythms and to compare these gene expressions with transcription of other cancer-associated genes. Methods: Twenty seven paired samples of tumour and benign tissue collected from patients who underwent cystectomy were analysed and compared to 15 samples of normal bladder tissue taken from patients who underwent cystoscopy for benign prostate hyperplasia (unrelated donors). Immunohistochemical analyses were made for clock and clock-related proteins. In addition, the gene-expression levels of 22 genes (clock genes, casein kinases, oncogenes, tumour suppressor genes and cytokeratins) were analysed by real-time quantitative PCR (qPCR). Results: Considerable up- or down-regulation and altered cellular distribution of different clock proteins, a reduction of casein kinase1A1 (CSNK1A1) and increase of casein kinase alpha 1 E (CSNK1E) were found. The pattern was significantly correlated with simultaneous up-regulation of stimulatory tumour markers, and a down-regulation of several suppressor genes. The pattern was mainly seen in aneuploid high-grade cancers. Considerable alterations were also found in the neighbouring bladder mucosa. Conclusions: The close correlation between altered expression of various clock genes and common tumour markers in urothelial cancer indicates that disturbed function in the cellular clock work may be an important additional mechanism contributing to cancer progression and malignant behaviour.publishedVersio

Relationship between Fecal Content of Fatty Acids and Cyclooxygenase mRNA Expression and Fatty Acid Composition in Duodenal Biopsies, Serum Lipoproteins, and Dietary Fat in Colectomized Familial Adenomatous Polyposis Patients

A few familial adenomatous polyposis studies have focused upon faecal sterols and bile acids but none has analysed the fecal content of fatty acids. We report here findings of an observational study on 29 colectomized familial adenomatous polyposis patients that describe the fecal content of fatty acids, and relate this to the proportions of fatty acids and levels of cyclooxygenase mRNA expression in duodenal biopsies, levels of serum lipoproteins, and diet. In the ileostomy group separately (n = 12), the fecal content of arachidonic acid was correlated negatively to the proportions of eicosapentaenoic acid and docosahexaenoic acid in duodenal biopsies. Total serum-cholesterol was negatively correlated to the fecal content of saturates and monounsaturates. The fecal palmitoleic acid/palmitic acid ratio was positively correlated to the levels of cyclooxygease-2 expression in duodenal biopsies.In the ileal-pouch-anal anastomosis group separately (n = 17), significant correlations were found between the fecal contents of oleic acid, linoleic acid, and alpha-linolenic acid, and the proportions of myristic acid, oleic acid and eicosaenoic acid in duodenal biopsies. Dietary monounsaturates were positively correlated to different fecal fatty acids. Future studies should focus on molecular mechanisms relevant to fatty acid metabolism, inflammation, and angiogenesis, in addition to nutrition

Daily intake of cod or salmon for 2 weeks decreases the 18:1n-9/18:0 ratio and serum triacylglycerols in healthy subjects

Intake of fish and omega-3 (n-3) fatty acids is associated with a reduced concentration of plasma triacylglycerols (TAG) but the mechanisms are not fully clarified. Stearoyl-CoA desaturase-1 (SCD1) activity, governing TAG synthesis, is affected by n-3 fatty acids. Peripheral blood mononuclear cells (PBMC) display expression of genes involved in lipid metabolism. The aim of the present study was to estimate whether intake of lean and fatty fish would influence n-3 fatty acids composition in plasma phospholipids (PL), serum TAG, 18:1n-9/18:0 ratio in plasma PL, as well as PBMC gene expression of SCD1 and fatty acid synthase (FAS). Healthy males and females (n = 30), aged 20–40, consumed either 150 g of cod, salmon, or potato (control) daily for 15 days. During intervention docosahexaenoic acid (DHA, 22:6n-3) increased in the cod group (P\0.05), while TAG concentration decreased (P\0.05). In the salmon group both eicosapentaenoic acid (EPA, 20:5n-3) and DHA increased (P\0.05) whereas TAG concentration and the 18:1n-9/ 18:0 ratio decreased (P\0.05). Reduction of the 18:1n-9/ 18:0 ratio was associated with a corresponding lowering of TAG (P\0.05) and an increase in EPA and DHA (P\0.05). The mRNA levels of SCD1 and FAS in PBMC were not significantly altered after intake of cod or salmon when compared with the control group. In conclusion, both lean and fatty fish may lower TAG, possibly by reducing the 18:1n-9/18:0 ratio related to allosteric inhibition of SCD1 activity, rather than by influencing the synthesis of enzyme protei

Resistance training in overweight women on a ketogenic diet conserved lean body mass while reducing body fat

<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to compare the effects of 10 weeks resistance training in combination with either a regular diet (Ex) or a low carbohydrate, ketogenic diet (Lc+Ex) in overweight women on body weight and body composition.</p> <p>Methods</p> <p>18 untrained women between 20 and 40 years with BMI ≥ 25 kg*m^-2were randomly assigned into the Ex or Lc+Ex group. Both groups performed 60-100 min of varied resistance exercise twice weekly. Dietary estimates were based on two 4-day weighed records. Body composition was estimated using Dual Energy X-ray Absorptiometry. Fasting blood samples were analyzed for total-, HDL- and LDL-cholesterol, triacylglycerols, and glucose.</p> <p>Results</p> <p>16 subjects were included in the analyses. Percentage of energy (En%) from carbohydrates, fat and protein was 6, 66, and 22 respectively in the (Lc+Ex) group and 41, 34, 17 in the Ex group. Mean weight change (pre-post) was -5.6 ± 2.6 kg in Lc+Ex; (p < 0.001) and 0.8 ± 1.5 kg in Ex; (p = 0.175). The Lc+Ex group lost 5.6 ± 2.9 kg of fat mass (p = 0.001) with no significant change in lean body mass (LBM), while the Ex group gained 1.6 ± 1.8 kg of LBM (p = 0.045) with no significant change in fat mass (p = 0.059). Fasting blood lipids and blood glucose were not significantly affected by the interventions.</p> <p>Conclusion</p> <p>Resistance exercise in combination with a ketogenic diet may reduce body fat without significantly changing LBM, while resistance exercise on a regular diet may increase LBM in without significantly affecting fat mass. Fasting blood lipids do not seem to be negatively influenced by the combination of resistance exercise and a low carbohydrate diet.</p