Search results for "TRACE"
showing 8 items of 3218 documents
Does differential iron supply to algae affect Daphnia life history? : An ionome-wide study
2019
The availability of iron (Fe) varies considerably among diet items, as well as ecosystems. Availability of Fe has also changed due to anthropogenic environmental changes in oceanic as well as inland ecosystems. We know little about its role in the nutrition of ecologically important consumers, particularly in inland ecosystems. Physiological studies in several taxa indicate marked effects of dietary Fe on oogenesis. We predicted that differential Fe supply to algae will impact algal Fe concentration with consequences on the life history of the freshwater grazer, Daphnia magna. We found that algal Fe concentration increased with Fe supply, but did not affect algal growth, indicating that the…
ATTIVITÁ DI RICERCA PER LO SVILUPPO DELLA ZOOTECNIA BIOLOGICA IN SICILIA
2008
Con l’intento di contribuire allo sviluppo del settore zootecnico biologico, gli autori hanno realizzato, attività di ricerca rivolte: - allo studio della possibilità di inserire, nella razione alimentare delle bovine e delle pecore in lattazione, fonti alternative al mais e alla soia, con la finalità di superare il problema degli OGM e di ridurre il rischio di contaminazione degli alimenti con micotossine; - alla valutazione degli effetti del carico animale al pascolo, finalizzato ad una maggiore efficienza produttiva dei sistemi pascolivi destinati agli ovini; - alla individuazione dei riflessi della dieta, variabile in funzione del concentrato utilizzato e del carico al pascolo, sulla qu…
Pratique et sémantique de la culture informationnelle
2015
In this paper, we present a formative experience in information literacy that can build on lasting from a reflexive, comparative approach skills; analytic and dialectic. On the theoretical side, we propose to reconcile the theories of human activity with simondiennes theories of technical culture. Trace analysis of learners permit to construct a summary ontology digital skills and shows the relevance of a semantic device training, which is part of the prospect of convergence between information cultures transliteracy kind.
Analyser les traces d’activité pour évaluer les ressources électroniques
2010
International audience; Afin d'améliorer la qualité de l'évaluation des ressources électroniques, nous proposons une approche intermédiaire entre l'analyse des logs et l'étude clinique de l'activité de recherche d'information documentaire. Nous montrons comment construire un système d'évaluation automatique des ressources côté utilisateur. Le modèle que nous proposons suppose un ensemble de concepts fondamentaux, et un processus pour l'implémentation que nous présentons. Un tel système a de nombreux avantages : il renforce l'apprentissage de l'usager, il est peu coûteux, et il donne beaucoup plus de précisions sur l'utilisation réelle des ressources et de ses fonctionnalités.
Jauna pieeja prostatas vēža cirkulējošu ekstracelulāro vezikulu selektīvai izolēšanai un to ietverto RNS biomarķieru analīze
2021
Audzēju producētās ekstracelulārās vezikulas (EVs) ir ieguvušas ievērojamu uzmanību zinātnieku vidū pēdējo gadu laikā, kā daudzsološs biomarķieru avots ar potenciālu pielietojumu vēža diagnostikā, prognostikā un monitorēšanā. Pacientu biofluīdos cirkulējošo EV izmantošanu šiem mērķiem apgrūtina tas, ka vēža izcelsmes EVs bieži sastāda zemu proporciju no kopējā parauga EV satura un šī proporcija mēdz atšķirties pacientu starpā. Tādēļ vajadzīgs meklēt jaunas pieejas, kas ļautu selektīvi izolēt un analizēt noteiktas EV subpopulācijas, kas bagātinātas ar vēža izcelsmes biomarķieriem. Adresējot šo aktualitāti, bakalaura darbā tika attīstīta un testēta jauna EV subpopulāciju izolēšanas metode – a…
RNS biomarķieru analīze prostatas vēža pacientu plazmas un urīna ekstracelulārajās vezikulās
2022
Ekstracelulārās vezikulas (EVs) ir heterogēni, ar membrānu norobežoti pūslīši, kas satur dažādas makromolekulas, tai skaitā RNS. EVs izdala visu veidu organisma šūnas un tās atrodas visos cilvēka bioloģiskajos šķidrumos. Ir pierādīta to loma prostatas vēža (PV) attīstībā, progresijā un metastazēšanās procesos. Šajā darbā iekļauta astoņu potenciālo RNS biomarķieru analīze PV un labdabīgas prostatas hiperplāzijas (LPH) pacientu plazmas un urīna EVs, kā arī PV pacientiem pirms un pēc radikālas prostatektomijas, izmantojot pilienu digitālo PCR. Tika novērota būtiska miR-375, piR-28004 un AMD1 līmeņa samazināšanās urīna EVs pēc radikālas prostatektomijas un tie tika izvirzīti kā potenciāli RNS b…
Variation in Sr uptake in the shell of the freshwater gastropod Bithynia tentaculata from Lake Arreo (northern Spain) and culture experiments
2010
The Sr uptake features in Bithynia tentaculata aragonite shells from monthly collections in Lake Arreo (northern Spain) over a two-year period are compared with those from the same species grown in culture experiments with similar waters under controlled temperature. The shell aragonite of B. tentaculata from Lake Arreo formed in isotopic equilibrium with the lake water. A comparison of the stable oxygen isotope values (δ18O) from the shells and waters allowed the selection of suitable shells for Sr uptake studies. The Sr/Ca molar ratio in B. tentaculata shells (Sr/Cashell) from the lake and from the culture experiments positively correlate with some chemical parameters like conductivity an…
The Use of Stable Isotope Ratio Analysis to Trace European Sea Bass (D. labrax) Originating from Different Farming Systems
2020
This study aimed to determine whether isotopic ratio mass spectrometry (IRMS) can discriminate farmed European sea bass according to different farming systems and geographic origins. Dicentrarchus labrax of commercial size from three different rearing systems (concrete tank inland, sea cages, and extensive methods in valleys or salt works) were collected at the trading period (autumn&ndash