Male rat sexual behavior requires aromatization of testosterone (T) to estradiol (E2) in the medial preoptic area (MPO) where estrogen receptors (ER) exist in two isoforms, ERα and ERβ. We hypothesized that E2 acts through estrogen receptor α (ERα) in the MPO to promote male mating behavior. Four groups of male rats were castrated, administered DHT s.c. and bilateral MPO implants delivering either: cholesterol, E2, propyl pyrazole triol (PPT, ERα agonist), diarylpropionitrile (DPN, ER β agonist), or 1-methyl-4-phenyl pyridinium (MPP, ERα antagonist). Additional gonadally intact males received bilateral MPO DPN implants. PPT maintained sexual behavior equally as well as E2, whereas mating was not maintained by cholesterol or DPN MPO implants. Exogenous T did not reinstate mating in animals that received MPP MPO implants. These findings indicate that, in the MPO, ERα is necessary and sufficient to promote copulatory behavior in male rats and ERβ is not sufficient for mating.

This thesis formulates a conceptual framework developed from field observations that describes the influence of surface depressions or potholes on runoff generation in the prairie pothole region of the North American prairies. The fill-and-spill of potholes results in intermittent surface water connectivity between potholes within the basin. The extent of connectivity between potholes is dependent on antecedent water levels. Dynamic connectivity between potholes results in dynamic contributing areas for runoff. The concept of connectivity is manifested in the conceptual curves presented in this thesis. These conceptual curves model the response of runoff events for landscape types found in the prairie pothole region, and capture the influence of the spatial distribution and extent of surface storage on contributing area. The conceptual curves differ due to variations in the spatial distribution and extent of surface storage volume.<p> An algorithm based on the conceptual framework proposed is presented. The algorithm, which uses the the D-8 drainage direction method, automates a methodology for identifying and quantifying runoff contributing area. The algorithm is applied in prairie pothole basins both to demonstrate its efficacy and to test the potential for using conceptual curves to describe the relationship between decreasing potential surface storage in the landscape and contributing area. The algorithm was applied to two digital elevation models (DEM) representative of the prairie pothole region. The first DEM was created using LiDAR elevation points at a 1 m resolution for the St. Denis watershed, and the second was created from orthophotos for the Smith Creek watershed at a 25 m resolution.<p> Fieldwork in the St. Denis watershed was carried out to both provide a basis for the conceptual framework proposed and to validate the results of the algorithm. The fieldwork involved gathering snow survey data, identifying and describing surface water conditions during a snow melt runoff event in 2006, and measuring pond levels from 2004 2007.<p> Results indicate that the proposed conceptual curves represent the non-linear relationship between potential surface storage and contributing area generated by the algorithm in the test basins. To test whether the underlying concepts of the algorithm were valid, the algorithm was used to model pond level depths measured in the St. Denis drainage basin after spring runoff in 2006 and 2007. An r2 value over 0.9 was calculated for the relationship between measured and modeled pond levels in both years. Based on this work, it is clear that any hydrologic study or model applied in the prairie pothole region should consider the effect of dynamic contributing areas on runoff generation.

A crucial question in drug addiction research concerns whether the varying reports of dopamine-independent and dopamine-dependent motivation can be integrated. According to one theory, the prior drug history of a subject — that is to say, whether they have received minimal or chronic drug exposure — determines whether opiate motivation is dependent upon the brainstem tegmental pedunculopontine nucleus (TPP) or dopamine neurotransmission. The biological analogue of this change is thought to be a switch in the signalling properties (from hyperpolarizing to depolarizing) of ventral tegmental area (VTA) gamma-aminobutyric acid subtype-A (GABAA) receptors. In this thesis, I demonstrate that the mechanisms underlying opiate motivation can be selected artificially by manipulating the signalling properties of VTA GABAA receptors, irrespective of the past drug history of the subject. Furthermore, I suggest that these same VTA GABAA receptors also play a similar role in controlling ethanol motivation. Indeed, the mechanisms underlying ethanol motivation can be doubly dissociated in a manner similar to that observed with opiates. However, whereas opiate motivation is TPP-dependent in the drug-naive state, I found that ethanol motivation was dependent on dopamine neurotransmission (via the D2 receptor) in drug-naive animals. Conversely, ethanol motivation was TPP-dependent in ethanol-deprived mice (as opposed to opiate motivation being dopamine-dependent in opiate-deprived animals). These effects are consistent with a VTA GABAA receptor switching mechanism identical to the one seen in the case of opiate motivation.

A pesar de la potencial del ecoturismo, todavía existen muchas comunidades que enfrentan obstáculos en realizar un proyecto exitoso del turismo. Vivir en el área natural o protegida no significa que la población local esté ganando del ecoturismo y desarrollándose. Un proyecto de ecoturismo exitoso no sólo tiene la carga de ser sostenible y dar beneficio al medio ambiente, el proyecto tiene que incluir la población local en una manera integral. El problema que será analizado en esta tesis es la multitud de barreras que existen frente a la movilización e integración de la población local, las cuales prohíben que la comunidad sea una parte fundamental del ecoturismo. En examinar los estudios de caso de proyectos de ecoturismo que han sido exitosos en conservar el medioambiente e integrar la comunidad local, se verán las estrategias que una comunidad puede emplear para poder superar las barreras de la movilización e integración y hacerse parte integral de un proyecto de ecoturismo.

The genetic structuring of populations can be influenced by present processes and past events. One of the largest historical events to affect the distribution and genetic characteristics of present-day North American biota is the Pleistocene glaciation. Thus, the study of post-glacial colonization patterns of species in northern landscapes can relay important ecological information, as species had to expand their range extensively following the retreat of the glaciers and are often at the terminal end of their expansion. These species consequently exhibit the genetic fingerprints of sequential founder events, in turn decreasing the genetic variation available for adaptation. Using amphibians to investigate post-glacial range expansion is advantageous, as they have limited dispersal abilities revealing fine-scale patterns and they are thought to be one of the first vertebrates to colonize post-glacial habitat. Therefore, to model the phylogeography of a primary colonizer and the population structure of anurans in northern landscapes, population genetics analyses of wood frogs (Lithobates sylvaticus) were performed in the James Bay area. Wood frogs were sampled from 17 localities around James Bay and genetic analyses were conducted with seven microsatellite loci and mitochondrial DNA sequences of the ND2/tRNATRP genes. Results show that the post-glacial recolonization of the James Bay area by wood frogs originated from the putative refugium in western Wisconsin, an area known as the Driftless Area. Two routes were taken by founders to colonize the James Bay area: one north-west of Lake Superior, colonizing western Ontario, and one through the Upper Peninsula of Michigan, colonizing southern and eastern Ontario and western Québec. Interestingly, the meeting of the two lineages south-west of James Bay led to the establishment of a zone of higher genetic variation than expected under the founder effect hypothesis. Additionally, population structure analyses revealed the segregation of three genetic populations east, north-west, and south-west of the bay, the latter showing the highest genetic variation and likely representing a zone of secondary contact. This study shows that past events such as post-glacial range expansions can explain present patterns of genetic variation and population structure, and that studies in northern landscapes may be very useful in understanding genetic patterns throughout the range of a species.

Wireless sensors networks are used in a variety of environments ranging from environment monitoring such as humidity and temperature, to environments like patient monitoring, habitat monitoring etc. Sometimes sensors are deployed in inaccessible or hazardous places, and they are battery operated; recharging or changing the sensor’s battery is almost impossible. In such scenarios, where the battery can not be recharged or changed, it is crucial to know in advance how long the battery will last so that the old sensor node can be replaced by a new one. Normally, in order to effectively utilize the battery the components of a wireless sensor node are turned off when not needed. This paper presents an in-depth analysis of the importance of switching sensor node components, and its impact on the life time prediction. A new energy model is presented which caters for the current and time consumed in switching from one mode to another. A comparison is made between scenarios where current consumption while switching is catered with the one where it is not catered. This was achieved by using on chip fuel gauge, with some limitation, which was verified by using digital multimeter.

Eutrophication of lakes and streams are nowadays a well known environmental problem and implies an enrichment of the nutrients phosphorus (P) and nitrogen (N). Phosphorus is considered to be the most important component for the growth of aquatic plants and leads in too large quantities to an intensification of growth. Phosphate (PO4) is the fraction of phosphorus that can easiest be taken up by plants and thus have the greatest impact on eutrophication. Increased plant growth in lakes and unfavorable conditions for aquatic animals are two examples of negative consequences. A significant portion of the increased nutrient supply to nearby water can be derived to phosphate leaching from agricultural areas, where private sewers and agriculture is two main sources. How much of the diffuse leakage of phosphate derived from each source is uncertain. With an improved understanding of how the source and flow distribution of phosphate relationship works in an agricultural dominated catchment could a more cost efficient planning for choice of methods against leakage of the nutrient be achieved. The source and flow distribution of phosphate was therefore studied and a high resolution set of SMHI's hydrological model HYPE where set up over the area. Sampling of phosphate from different parts of the area where used together with modeled water flow and phosphate transport where calculated. Upstream and downstream dynamics of phosphate were compared during high water flow. Also sampling of the oxygen isotopic composition in phosphate ions from sewage and agricultural land were analyzed and used to estimate the source distribution at different situations of water flow. The collected information from these studies where used to identify from which source to phosphate and during which flow the leakage of phosphate where the most in the area. In addition to this an evaluation of the importance of the time and space resolution for the HYPE-model where made. Phosphate transports in space shows that the sewage-dominated basins where the areas that leak most phosphate per area unit and during low water flows. Agricultural areas account for more significant leakage during a high water flow. This is evident in autumn and winter and less evident during spring and summer. Oxygen isotopic composition of phosphate ions from wastewater and agricultural land could with a 99 % confidence be separated. This information was used for source separation of phosphate sources where sewage was the main source of water flow up to 23 l/s. At higher water flow increases agricultural land as a primary source and increases positively linearly with increasing water discharge. Both studies indicate that sewage accounts for the greatest leakage during low water. During a snow-melting period the phosphate leaching is highest at the beginning and gradually flushed out from the soil when the water flow remains high for several days in a row. The importance of a high resolution time and space step affected modeled data marginally positive in HYPE where time step had a more important role.

The neural correlates that underpin fine motor control of the hand and their connections with the primary motor cortex (M1) require further investigation. Brodmann’s area 5 located in the superior parietal lobule (SPL) is suggested to be an important cortical area involved in the processing of somatosensory input important for precision movements. Area 5 is present in monkey species capable of opposable thumb movements and it is proposed that this area evolved with the ability to execute manual behaviours such as pinch grip. Further, area 5 is dominated by the representation of the hand and forelimb, and has direct connectivity with M1 implicating its role in the control of hand movements. Few studies have investigated the function of area 5 in humans and none have examined the connectivity between area 5 and ipsilateral M1. This thesis presents a novel approach to study the influence of area 5 on M1 output in healthy and awake humans during the processing of somatosensory inputs and during performance of motor tasks involving the hand. Using paired pulse transcranial magnetic stimulation over left area 5 and ipsilateral M1, the connections between the two cortical loci was probed. It was hypothesized that area 5 would facilitate M1 output at short and long latencies during the processing of tactile inputs and during the performance of motor tasks compared to rest. The current results demonstrate that changes in M1 output are task and temporally specific. Facilitation of the motor evoked potential (MEP) was present at short latency of 6 ms during the processing of somatosensory input whereas inhibition was present during conditions where the hand was performing a task with the thumb and index finger. Further, an inhibitory effect was seen at 40 ms during cutaneous stimulation. In experiments 1 and 2, there was no net influence of area 5 on M1 output observed at rest. The findings presented may have revealed a novel path with which to alter the motor output, and possibly movement of hand muscles.

This thesis formulates a conceptual framework developed from field observations that describes the influence of surface depressions or potholes on runoff generation in the prairie pothole region of the North American prairies. The fill-and-spill of potholes results in intermittent surface water connectivity between potholes within the basin. The extent of connectivity between potholes is dependent on antecedent water levels. Dynamic connectivity between potholes results in dynamic contributing areas for runoff. The concept of connectivity is manifested in the conceptual curves presented in this thesis. These conceptual curves model the response of runoff events for landscape types found in the prairie pothole region, and capture the influence of the spatial distribution and extent of surface storage on contributing area. The conceptual curves differ due to variations in the spatial distribution and extent of surface storage volume.<p> An algorithm based on the conceptual framework proposed is presented. The algorithm, which uses the the D-8 drainage direction method, automates a methodology for identifying and quantifying runoff contributing area. The algorithm is applied in prairie pothole basins both to demonstrate its efficacy and to test the potential for using conceptual curves to describe the relationship between decreasing potential surface storage in the landscape and contributing area. The algorithm was applied to two digital elevation models (DEM) representative of the prairie pothole region. The first DEM was created using LiDAR elevation points at a 1 m resolution for the St. Denis watershed, and the second was created from orthophotos for the Smith Creek watershed at a 25 m resolution.<p> Fieldwork in the St. Denis watershed was carried out to both provide a basis for the conceptual framework proposed and to validate the results of the algorithm. The fieldwork involved gathering snow survey data, identifying and describing surface water conditions during a snow melt runoff event in 2006, and measuring pond levels from 2004 2007.<p> Results indicate that the proposed conceptual curves represent the non-linear relationship between potential surface storage and contributing area generated by the algorithm in the test basins. To test whether the underlying concepts of the algorithm were valid, the algorithm was used to model pond level depths measured in the St. Denis drainage basin after spring runoff in 2006 and 2007. An r2 value over 0.9 was calculated for the relationship between measured and modeled pond levels in both years. Based on this work, it is clear that any hydrologic study or model applied in the prairie pothole region should consider the effect of dynamic contributing areas on runoff generation.

Syftet med detta examensarbete är att undersöka om och hur elever uppfattar begreppen omkrets och area. Då vi båda studerar till matematiklärare anser vi att detta arbete kan stärka oss i vår lärarroll samt utveckla oss inom arbetsområdet geometri. Vi började med att göra en diagnos med ca 40 elever. Genom att djupintervjua tre av eleverna fick vi en bättre förståelse för varför eleverna svarade som de gjorde på diagnosen. Genom att göra en läromedelsgranskning av de aktuella läroböckerna ville vi se om dessa kan spela roll när det gäller elevernas kunskap inom detta område. Resultatet visar att de flesta eleverna klarade att räkna uppgifter inom området omkrets eller area och använda sig av dessa begrepp när uppgiften var ”given”, på så sätt att eleverna får veta vad som ska räknas ut (area eller omkrets). Problemen dyker upp när eleverna får svårare uppgifter som är konstruerade på ett sådant sätt att de inte får en given metod att lösa uppgiften, det vill säga när det är oklart hur eleverna ska angripa uppgiften.