Effects of abandonment on plant diversity in seminatural grasslands along soil and climate gradients

Questions: What are the effects of abandonment on plant diversity in semi-natural grasslands? Do the effects of abandonment on taxonomic and functional diversity vary along environmental gradients of climate and soil? Location: West and mid-Norway. Methods: Plant composition was surveyed in 110 subplots of 4 m2 in 14 sites across grazed and abandoned semi-natural grasslands. Climate data were extracted and soil composition analysed. To reduce the number of explanatory variables and deal with collinearity, we performed PCA. Data on the plant species vegetative height (H), leaf dry matter content (LDMC), specific leaf area (SLA), seed mass (SM) and number of seeds per plant (SNP) for 175 species were extracted from the LEDA database. Measures of plant diversity (species richness, CWM of functional traits and functional diversity (evenness and range)) were calculated for each subplot. To estimate the effects of abandonment on plant diversity and examine how these effects are moderated by gradients in soil and climate, we fitted mixed models to the data including site as a random effect. Results: Species richness in the subplots was lower in abandoned semi-natural grasslands, especially on more calcareous soils. CWM H, LDMC and SM were higher in abandoned semi-natural grasslands. CWM LDMC was only higher in the driest subplots. The ranges in H, SLA and SM, as well as evenness in LDMC were also higher in abandoned semi-natural grasslands, but the range in LDMC was lower. Conclusions: It is important to assess both taxonomic and functional diversity to understand ecosystem processes. The species pool in ecosystems influenced by a long history of intermediate grazing includes a high proportion of low stature, grazing-tolerant plant species. Abandonment of extensive land-use practices will cause a decline in taxonomic diversity (plant species richness) in such systems due to increased abundance of plants with high stature that outcompete the lower, grazing-tolerant plants. This process is predominant especially if moisture, soil fertility and pH are at intermediate levels. Changes in species communities due to abandonment will also influence ecosystem functioning, such as nutrient turnover and fodder production resilience. (Résumé d'auteur

Bumblebees learn a relational rule but switch to a win-stay/lose-switch heuristic after extensive training

Mapping animal performance in a behavioral task to underlying cognitive mechanisms and strategies is rarely straightforward, since a task may be solvable in more than one manner. Here, we show that bumblebees perform well on a concept-based visual discrimination task but spontaneously switch from a concept-based solution to a simpler heuristic with extended training, all while continually increasing performance. Bumblebees were trained in an arena to find rewards on displays with shapes of different sizes where they could not use low-level visual cues. One group of bees was rewarded at displays with larger shapes and another group at displays with smaller shapes. Analysis of total choices shows bees increased their performance over 30 bouts to above chance. However, analyses of first and sequential choices suggest that after approximately 20 bouts, bumblebees changed to a win-stay/lose-switch strategy. Comparing bees’ behavior to a probabilistic model based on a win-stay/lose-switch strategy further supports the idea that bees changed strategies with extensive training. Analyses of unrewarded tests indicate that bumblebees learned and retained the concept of relative size even after they had already switched to a win-stay, lost-shift strategy. We propose that the reason for this strategy switching may be due to cognitive flexibility and efficiency

Delovanje anestezije metakainom na parameter krvi bakalara

Anesthetics are commonly used in aquaculture to immobilize fish before handling in order to minimize stress responses that may influence fish quality negatively. However, anesthetics may actually trigger secondary stress responses by affecting blood respiratory properties and disturbing acid-base and electrolyte balance. In this respect we can monitor possible stress responses caused by anesthesia by measuring key blood parameters. In the present investigation we have studied the effect of metacain anesthesia on these blood parameters in Atlantic cod (Gadus morhua). In total, 6 fish with an average length of 45 cm and weight of 1 kg were used in this study. The fish were kept in 2 m3 tank with air saturated running sea water (34 ppt, 8.5C) at natural light conditions (November 2010, Bergen, Norway) and fed with commercial cod feed. The test fish were anesthetized with metacain (1g/10L diluted in sea water) until fully immobilized prior to blood sampling from ductus cuvieri. These fish recovered after blood sampling. The control fish were killed with a sharp blow to the head and blood was sampled immediately after by cardiac puncture. Ice-cold syringes with Heparin lithium salt were used for blood sampling from both groups. The following parameters were measured: pH, Hct, Hb, mLO2/gHb, Glu, Lac and plasma ions (Na+, K+, Li+, Mg2+, Ca2+, Cl-, F-, Br-, NO3-, PO43- and SO42-) for both groups. The blood parameters were measured at 15°C and 100% air saturation after being equilibrated for 20 min. Oxygen carrying capacity was measured using a modified Tucker chamber technique. The other blood parameters were analyzed by standard techniques (pH electrode/meter, photometer, hematocrit centrifuges) as well as using i-STAT hand-held analyzer (used cartridges CG4+ and CHEM8+). The results show a significant acidification of the blood from metacain anesthetized fish compared to control fish. This pH decrease is partly caused by the acidity of metacain itself since there were no significant changes in Lac, which probably is due to the equilibration of blood with air for 20 minutes. This effect may cause arterial desaturation and reduced metabolic scope. Hct, Hb, mLO2/gHb, Glu and Lac showed no significant differences between the two groups except for a larger variability of these parameters (higher standard deviation) for the metacain anesthetized fish. However, there was a significant increase in plasma Na+ cations, which could be a direct effect of metacain on the Na-K-transport mechanism in gills leading to an ion imbalance. In conclusion, the acidification caused by metacain itself, during anesthesia, appears to be the most serious problem for the fish during anesthesia and precaution should be taken in order to avoid metabolic stress until full recovery

Towards a critical edition of Ubertino of Casale’s Arbor Vite Crucifixe Iesu.

L’Arbor vite crucifixe Iesu, vasta opera composta nel 1305 alla Verna dal francescano spirituale Ubertino da Casale, è uno dei più antichi, se non il primo esempio del fortunato genere bassomedievale della Vita Christi. Nonostante la sua importanza come fonte primaria dello spiritualismo francescano e delle pratiche di devozione del XIV-XV secolo, il testo accessibile solo nell’edizione incunabola del 1485. Il contributo sottolinea i rischi di una tale carenza ecdotica attraverso il caso della "Absorbeat", breve preghiera contenuta nell’Arbor e falsamente attribuita a Francesco d’Assisi a causa di un errore di trasmissione del testo. Offre inoltre, nell’ambito del progetto di edizione critica promosso dalla SISMEL, un primo affresco della tradizione manoscritta e dei principali problemi filologici sollevati dal testo. Viene riservata una particolare attenzione ai manoscritti di origine aragonese e, tra questi, al codice 88 della Biblioteca Capitolare di València.The Arbor vite crucifixe Iesu, a huge latin book written at the hermitage of La Verna (Tuscany) by the spiritual franciscan Ubertino of Casale in 1305, is an early, if not the first example of the widespread "Life of Christ" genre of the late Middle Ages. Despite its importance as a primary source for the spiritual franciscan movement and for the devotional practices of the XIV-XV century, the text can be read only in a 1485 incunable edition. The paper underline the risks of such an absence of a modern critical edition, by examining the case of the "Absorbeat", a short prayer included in the Arbor and falsely ascribed to st. Francis of Assisi, due to an error in the textual tradition. It provides also, as a part of the project of a new critical edition promoted by the SISMEL, a first overview of the manuscript tradition and of the main philological problems raised by the text. A special attention is reserved to the manuscripts of Aragonese origin and, among them, to that of València, Biblioteca capitular, cod. 88.Humanidade

"Arbeidstakerspørsmål eller klimaspørsmål?" - Fagbevegelsen og det grønne skiftet

I vår tid anses ofte klimasaken som en av de største, om ikke den største saken. Effekten av klimaendringene og omstillingen som kreves for å møte disse vil ha store konsekvenser for hele samfunnet, så vel som arbeidslivet. Knyttet til disse potensielle endringene i arbeidslivet er ofte inntrykket man får at det eksisterer en frykt blant mange, særlig innen industrien for hva som vil skje med deres arbeidsplasser innen en slik endring. I den grad er det interessant å se hvordan fagbevegelsen forholder seg til spørsmål om klima, og grønn omstilling, samt hvordan fagbevegelsen selv ser sin rolle i dette. Norsk fagbevegelse har allerede fått kjent på effekten av klimadebatten internt, og alle LO forbund har en egen klimapolitikk, så vel som at LO også har dette. Knyttet til forbundenes klimapolitikk er det ulike interesser som former og preger disse. I den grad søker denne studien til å si noe om hvilke interesser som eksisterer innen norsk fagbevegelse, og hvordan dette preger deres oppfatning av egen rolle i omstillingsprosessen. Samt hvordan disse interessene preger hva forbundene, og fagbevegelsen kan gjøre, og aktivt gjør i denne prosessen. For å få svar på dette er det gjennomført intervju med representanter for ulike forbund, på ulike nivå. Samt en dokumentanalyse av ulike vedtekter og handlingsprogram. Temaene som har preget intervjuene er spørsmål om klima, politikk, og fagbevegelsens rolle i samfunnet. Forbundene som deltar i studien representerer alle ulike deler av arbeidslivet, og oppfattes derfor til å ha ulike interesser i klimasaken. Gjennom intervjuene ble det skissert ulike interesser knyttet til sektor og medlemmenes strukturelle plassering innenfor arbeidsmarkedet. Selv om utvalget er noe begrenset gir det grunnlag for å gi tentative svar rundt hva disse interesser er, og hvilken effekt de kan ha for klimapolitikken til forbundene og fagbevegelsen. Flere forbund med en tettere tilknytning til industrien virker til å trekke mer på en forståelse rundt behov for arbeidsplasser, fremfor klimainteresser. Samtidig som det er stemmer i fagbevegelsen både med en noenlunde tilknytning til industrien og uten som ønsker å kjempe frem sterkere krav til omstilling. Med de ulike interessene har også forbundene ulike måter og midler de kan trekke på for å påvirke og se sin politikk gjennomført i samfunnet. Det vil bli diskutert hvordan forbundene ser potensiale for å påvirke, samt diskusjoner på hvilket potensial som ligger i disse.MasteroppgavenSOS360MASV-SO

Système politique et mobilité sociale

L'analyse des processus de mobilité sociale mobilise l'intérêt des sociologues depuis une trentaine d'années ; pourtant ni ce terme ni les concepts auxquels il fait appel ne font l'objet d'un consensus en sociologie. Le débat qui s'est développé autour de ce problème semble s'ordonner selon deux axes. D'une part, des discussions de type technique, de l'autre des oppositions plus radicales de nature théorique ou épistémologique. Le premier plan concerne tous les problèmes liés à la constitution et à l'interprétation des indicateurs de mobilité sociale : définition de critères permettant de constituer les classes ou groupes sociaux, mesure du flux de mobilité, problèmes liés à l'existence d'une mobilité structurelle, etc. Le second axe, d'une nature différente, met en question la légitimité du concept de mobilité sociale et, par conséquent, l'utilité de ce type de recherche quelles qu'en soient par ailleurs les modalités techniques (...)