Session C5: Downstream Migration of the European Eel (A. anguilla): Movement Patterns and the Potential Impact of Environmental Factors

Abstract: Recruitment of European eels (Anguilla anguilla) has declined to the extent that they have been added to the IUCN Red List of Threatened Species. Therefore, it is critical to ensure that eels complete their outward river migration in order to contribute to the available spawning stock. We conducted a four-year (2007-2011) telemetry study to understand the migratory behaviour and potential impact of environmental factors on the eel during this critical life stage. Out of 399 female eels tagged with acoustic transmitters, only 28 % demonstrated clear downstream migratory behaviour. Fifty-five percent were detected exhibiting no downstream migration behaviour and 17 % were not detected at any monitoring station. Movement patterns of downstream-migrating (silver) eels were characterised by nocturnal activity and seasonal migration, with distinct peaks in autumn and spring. Migration was often discontinuous and exhibited phases of active locomotion and expanded stopovers. The most important determinants of movement activity were water temperature, cumulative precipitation, and moonlight, although the significance varied by season and location in the river basin. Our results evidence a discontinuous, stepwise migration over an extended period. Furthermore, our findings indicate that migration success depends on holding duration prior to tagging, and environmental predictors with varying importance depending on the season, as well as the locations of capture, tagging and release

Effects of in vitro potassium on ammoniagenesis in rat and canine kidney tissue

Effects of in vitro potassium on ammoniagenesis in rat and canine kidney tissue. Decreased ammonium (NH4+) excretion is associated with hyperkalemia. To determine if potassium could directly influence renal ammonia production, we investigated ammoniagenesis by rat and canine renal cortical tissues in vitro at different potassium concentrations. Renal tissue from normal and acidotic rats and normal dogs incubated in glutamine, lactate, and 7 to 10mEq/liters of potassium or 25mEq/liters of potassium produced significantly less ammonia than slices incubating in glutamine, lactate, and 4 to 5mEq of potassium. Glutamate accumulation, which follows glutamine deamidation, did not decrease and even increased at 25mEq/liters of potassium. With glutamine as the sole substrate, decreased ammoniagenesis was seen only at higher potassium concentrations (> 16mEq/liters) than when lactate was also present. The depression to glutamine ammoniagenesis by high concentrations of potassium was partially obliterated in an anaerobic environment. When glutamate replaced glutamine as the precursor, renal ammonia produced by slices in 7 and 25mEq/liters was again significantly lower than by slices incubating in 4mEq/liters. We blocked glutamine synthesis by rat kidney slices with dl-methionine dl-sulfoximine when glutamate was the renal ammonia precursor. This essentially allows glutamate deamination to produce ammonia. Potassium depressed glutamate deamination significantly at 7mEq/liters (↓ 13%) and at 25mEq/liters of potassium (↓ 35%) as compared to 4mEq/liters. The above findings are consistent with a major depressive effect of in vitro potassium on glutamate deamination in rat and canine kidneys. Other evidence, especially from rat tissue studies, suggests that potassium also may affect glutamine deamination directly. Rat kidney slices incubating in the high potassium medium of 7mEq/liter or greater also consumed less oxygen in the presence of glutamine (P < 0.01), oxidatively decarboxylated less glutamine (P < 0.02) and produced less glucose from glutamine (P < 0.01).Effet du potassium in vitro sur l'ammoniogenèse dans tissu rénal de rat et de chien. Une diminution de l'excrétion d'ammoniaque (NH4+) est associée à l'hyperkaliémie. Afin de déterminer si le potassium peut influencer directement la production rénale d'ammoniac, nous avons étudié l'ammoniogenèse dans le tissu rénal cortical de rat et de chien in vitro à différentes concentrations de potassium. Du tissu rénal provenant de rats normaux et en acidose et de chiens normaux incubés dans de la glutamine, du lactate, et 7 à 10mEq/litres de potassium ou 25mEq/litres de potassium produit significativement moins d'ammoniac que des tranches incubées dans de la glutamine, du lactate, et 4 à 5mEq/litres de potassium. L'accumulation de glutamate, consécutive à la deamination de la glutamine, n'a pas diminué et même a augmenté à 25mEq/litres de potassium. Avec la glutamine comme seul substrat, la diminution de l'ammoniogenèse n'a été observée qu'à des concentrations de potassium supérieures (> 16mEq/litres) à celle nécessaire quand le lactate est présent. La dépression de l'ammoniogenèse due à la glutamine au moyen de concentrations élevées de potassium est partiellement abolie par un environnement anaérobique. Quand la glutamine est remplacée par du glutamate, le rénale d'ammoniac produit par des tranches dans des milieux à 7mEq/litres et 25mEq/litres est là encore significativement inférieur à celui produit par des tranches incubées dans un milieu à 4mEq/litres. Nous avons bloqué la synthèse de glutamine dans les tranches de rein de rat au moyen de la dl-méthionine dl-sulfoximine quand le glutamate était le précurseur de rénale d'ammoniac. Ceci permet à la déamination du glutamate de produire de l'ammoniac. Potassium diminue significativement la déamination du glutamate à 7mEq/litres (diminution de 13%), et à 25mEq/litres (diminution de 35%) par comparaison avec les valeurs obtenues à 4mEq/litres. Ces constatations sont compatibles avec un effet dépresseur majeur du potassium in vitro sur la déamination du glutamate dans les reins de rat et de chien. D'autres arguments, tirés essentiellement des études sur le tissu de rat, suggèrent que le potassium peut aussi affecter la déamination du glutamate directement. Des tranches de rein de rat incubées dans un milieu riche en potassium (7mEq/litres ou plus) consomment moins d'oxygène en présence de glutamine (P < 0,01), décarboxylent moins de glutamine par oxydation (P < 0,02) et produisent moins de glucose à partir de la glutamine (P < 0,01)

Integration of multimodal input by using agents

Today, user interfaces normally consist of a screen, and a pointing device and a keyboard for input. However, as more advanced technology and methods appears, there should be good chances to utilize these for more natural and effective human-computer interfaces. The main motivation is to get a more natural and easy to use interface, and the computer should understand the user without too much effort from the user. Intelligent interfaces could be a solution to achieve this goal. The main focus in this thesis, is multimodal input which combines different input modalities to achieve the user's goal. A framework has been designed where the user has the possibility to change between input modalities. The system should integrate the information given in different input modalities to one joint meaning. In this architecture, input could either be location or command input, and different modalities could be used for each input type. The example described later on in this thesis combines either speech or written text as command input, with either map input or physical position for location input. An agent-based blackboard architecture are used for collecting input. Agents collect information directly from the user. Each agent represent their own input modality, and is responsible to analyse input. As this is done, the agent send the information to a common blackboard which hold the latest information from each agent. An own agent which is responsible for fusing this information to one common meaning, collects the information from the blackboard and integrate it to one joint meaning. This joint interpretation decides what should be done to which object. Since the modalities are independent of each other, other modalities could easily be added with just small changes to other parts of the system as long as it is an command or location input which agrees to the currently representation structure

Topplederlønninger i norske AS og ASA bedrifter. Hvordan er nettverksstrukturen for toppledere som er styremedlem i norske ASA bedrifter, og har den sammenheng med deres lønninger?

Master's thesis in Business administrationHovedformålet med denne oppgaven er å se på hvordan nettverkverksstrukturen blant toppledere i norske AS og ASA bedrifter ser ut. Videre er det ønskelig å se på hvordan topplederes nettverk i styrer kan påvirke deres egne lønninger. Oppgavens fokus vil ligge på overlappende styremedlemskap og hvordan slike overlappinger påvirker topplederlønninger. I oppgaven har det blitt presentert relevant teori om virksomhetsstyring, overlappende styremedlemskap og måleparametere som er aktuelle for oppgavens nettverksanalyse. Med dette er det ønskelig å danne et fundament som oppgaven kan bygge videre på. Teorien skal danne en forståelse av topplederens posisjon i organisasjoner, og hvordan potensielle nettverk kan ha sammenheng med topplederens lønning. Videre skal den gi innblikk i styrets ansvar i forhold til fastsettelse av lønninger. Oppgaven har en kvantitativ forskningstilnærming, der datainnsamlingen er basert på årsrapporter fra 2011 og et datasett fra Tore Opsahl og Cathrine Seierstad. Datasettet viser en oversikt over styresammensetninger i Norge i august 2011. I diskusjonsdelen fremlegges det en deskriptiv presentasjon av nettverket, der en ser på koblingene blant toppledere i norske styrer. Videre finner man positiv sammenheng blant de lokale og direkte nettverksmåletallene og topplederlønninger. I oppgaven har vi forsøkt å finne nettverksrelaterte forhold som har innvirkning på forklaringene av funnene i metodedelen. Dette for å finne mulige argumenter og forklaringer på hvorfor denne sammenhengen finner sted på et lokalt nivå, og ikke på et globalt nivå. Resultatene fra denne forskningen vil kunne være nyttig for å illustrere norske topplederes posisjon som følge av styreverv. Videre kan forskningen kartlegge innvirkningen nettverk har på topplederes posisjon i bedrifters styrer. Samtidig vil den være nyttig for å kunne se hva som kan være mulige årsaker og sammenhenger til den positive sammenhengen mellom overlappende styremedlemskap blant toppledere og topplederlønninger