Thesis (M. Sc.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 71-73).

The vegetation of the Nooitgedacht section of the Loskop Dam Nature Reserve resembles Bankenveld vegetation and differs from the other areas of the reserve. This study was undertaken to identify, classify, and describe the plant communities present on this section, and to determine their veld condition. The Braun-Blanquet approach was followed to classify the different plant communities. A total number of 170 sample plots (100m2) were placed in all homogeneous vegetation units in a randomly stratified basis. The Ecological Index Method (EIM) was used to determine the veld condition. Data were collected using the steppoint method and incorporated into the GRAZE model from where the veld condition was calculated. A minimum of 400 step points were surveyed in each community with more points in the larger communities. Plant community data was analysed using the JUICE software program. A total of 11 plant communities were identified. The overall veld condition score indicates the vegetation to be in a good condition, resulting in a high grazing capacity. / Environmental Sciences / M. Sc. (Nature Conservation)

Made available in DSpace on 2016-06-02T19:29:44Z (GMT). No. of bitstreams: 1 TeseAS.pdf: 1169927 bytes, checksum: 6183f668fbb98ca0b2eab21f04500fb6 (MD5) Previous issue date: 2002-12-13 / Financiadora de Estudos e Projetos / The cocoa production region of southern Bahia harbors the largest fragments of Atlantic Forest in the State of Bahia, possessing a high frequency of endemics and species richness, and being presently considered a priority area for biodiversity conservation. Nevertheless, the process of implementing Conservation Units in the region is not keeping up with the rate of change in local land use. Among the strategies of non-governmental organizations to help in the conservation of the Una Biological Reserve (the largest forest fragment in the cocoa production region) is the creation of Private Nature Reserves. In the present work, the process of implementation of the Ecoparque do Una Private Nature Reserve was assessed. The Ecoparque do Una is a 383 ha area contiguous to the Una Biological Reserve (UBR), and is intended to be a model for sustainable development and natural resource utilization. The analysis of the social and economic relations between the Ecoparque and its neighboring properties indicated that both areas lack economic integration. However, employees at the Ecoparque are all native to the region, a situation that contributes for the Ecoparque to be more easily accepted by the local community. The number of visitors to the area is increasing monthly from 1998 to present, but the public is constituted typically by people coming from other regions. This limits the process of comprehension, by people from the cocoa production region, of the importance of the Ecoparque for conservation of natural resources. The cost of the entry ticket to the Ecoparque was pointed by tourism operators as the greatest barrier for marketing the Ecoparque as a product, restricting the aggregate value of tourism in the region. In spite not being yet an economically sustainable touristic product, because its expenditures are higher than the direct incomes from public visitation, this model of development is in process of becoming sustainable. All the environmental factors considered, the Ecoparque is meeting the requisites of a sustainable enterprise with social responsibility, environmental conservation and economic development. / A região cacaueira do Sul da Bahia abriga hoje os maiores fragmentos de Floresta Atlântica no Estado, com elevado endemismo e grande riqueza de espécies, sendo considerada atualmente como uma das áreas prioritárias para a conservação da biodiversidade. Entretanto a implantação de Unidades de Conservação na região não está acompanhando as mudanças atuais na dinâmica do uso da terra. Uma das estratégias utilizadas por organizações não-governamentais para auxiliar a conservação da Reserva Biológica de Una (maior fragmento florestal da região cacaueira) está sendo a criação de reservas privadas em seu entorno. Este trabalho avaliou a dinâmica da implantação de uma Reserva Particular do Patrimônio Natural, o Ecoparque de Una, área com 383 ha, contígua à Reserva Biológica de Una e que tem por objetivo servir como modelo de desenvolvimento sustentável para a utilização dos recursos naturais. As relações sociais e econômicas entre a Reserva e as propriedades lindeiras foram analisadas, mostrando que ainda não há integração econômica entre estas; porém, todos os funcionários são nativos da região, o que colabora para a aceitação da Reserva pela comunidade local. A visitação pública na área está aumentando em todos os meses, desde 1998 até o momento, porém, ainda com público caracterizado por visitantes de outras regiões, o que limita o processo de compreensão, pelos habitantes da região cacaueira, da importância da conservação de seus recursos naturais. O valor cobrado para ingressar na área da Reserva foi apontado pelas operadoras de turismo como o grande obstáculo para a comercialização do produto Ecoparque , o que restringe a agregação de valor ao turismo da região. Apesar de ainda não ser um produto turístico economicamente sustentável, pois suas despesas não são cobertas pela receita direta da visitação pública, pode-se afirmar que este modelo de desenvolvimento está caminhando para sua sustentabilidade econômica. Considerando-se todos os fatores ambientais analisados, a Reserva está cumprindo as premissas de uma atividade sustentável, com responsabilidade social, conservação ambiental e desenvolvimento econômico.

Genetic and environmental protective factors and risks modulate brain structure and function in neurodegenerative diseases and their preclinical stages. We wanted to investigate whether the years of formal education, a proxy measure for cognitive reserve, would influence hippocampal structure in Alzheimer’s disease patients, and whether apolipoprotein Eε4 (APOE4) carrier status and a first-degree family history of the disease would change a possible association. Fifty-eight Alzheimer’s disease patients underwent 3T magnetic resonance imaging. We applied a cortical unfolding approach to investigate individual subregions of the medial temporal lobe. Among patients homozygous for the APOE4 genotype or carrying both APOE4 and family history risks, lower education was associated with a thinner cortex in multiple medial temporal regions, including the hippocampus. Our data suggest that the years of formal education and genetic risks interact in their influence on hippocampal structure in Alzheimer’s disease patients.

La circulation artérielle coronaire est un système complexe dont les méthodes de mesures invasivespermettent une évaluation en pratique clinique.Matériels et méthodes Nous développons, dans deux revues, les principes et méthodes des différentes techniques invasivesde mesure du flux coronaire en pratique clinique. Puis nous étudions l’impact clinique de l’utilisationde la Fractional Flow Reserve (FFR) dans l’évaluation des sténoses coronaires intermédiaires, lesmoyens pharmacologiques pour mesurer la FFR et sa corrélation avec l’évaluation angiographique enfonction des facteurs de risque cardiovasculaires. Enfin, nous décrivons les principes et méthodesd’une technique de mesure du flux coronaire segmentaire permettant d’obtenir la FFR, le flux et lesrésistances absolues avec un microcathéter de perfusion qui, sur un principe de thermodilutionpermet d’évaluer distinctement la macro et la microcirculation coronaire.Résultats Nous recommandons une valeur seuil de FFR de 0,80 pour guider la revascularisation car le nombred’événements cardiovasculaires et la mortalité sont spontanément supérieurs chez les patients avecune FFR <0,80 comparativement à une FFR ≥0,80 (9,4 vs. 4,8%, P=0,06 et 7,5 vs. 3,2%, P=0,06;respectivement). Nous avons étudié différents agents hyperémiants permettant de mesurer la FFR:l’adénosine (100 μg à 200 μg) permettant d’obtenir une hyperémie maximale, et le produit decontraste permettant d’atteindre 65% de cette hyperémie maximale. La mesure de la FFR avec duproduit de contraste permet de meilleures performances diagnostiques que les indices de reposcomparé à la FFR sous adénosine. Nous avons établi que la corrélation entre la FFR et le degré desténose angiographique est faible et inversement proportionnel au nombre de facteurs de risquecardiovasculaires, particulièrement chez les patients diabétiques. Enfin, nous avons décrit dans troisétudes, le principe de thermodilution coronaire et la méthode de mesures du flux coronaire et desrésistances microvasculaires avec un microcathéter de perfusion intracoronaire spécifique. Nousavons montré que cette technique est précise (R=0,98), qu’elle induit une hyperémie maximale etlocale sans agent hyperémiant et quelle est reproductible chez l’homme (R=0,91).Conclusion La compréhension de la circulation coronaire et l’application chez l’homme des techniques demesure du flux coronaire segmentaire sont essentielles tant en pratique clinique courante qu’enrecherche. / Coronary circulation is complex and highly regulated while invasive coronary flow measurements techniques allow the assessment of coronary physiology in clinical practice. Material et methods We describe in two reviews the principles and methods of different invasive coronary flowmeasurements techniques in clinical practice. We study the clinical impact of fractional flow reserve(FFR) in intermediate coronary stenosis, the hyperemic agents and dosage to measure FFR and FFRcorrelation with angiographic indices according to risk factors accumulation. Finally, we describe the principle and method of coronary flow and microvascular resistances measurements with a dedicated infusion microcatheter for coronary thermodilution to obtain assessment of macro and microvascular components of coronary circulation. Results We recommend the FFR cut off value of 0.80 to guide revascularization based on our study showing higher myocardial infarction and death rate in patients treated with medical therapy and FFR<0.80compared to those with FFR>0.80, respectively 9.4 versus 4.8%, P=0.06 and 7,5 versus 3,2%, P=0.06. We studied different hyperemic agents and dosages and showed that intracoronary adenosine at 100μg to 200 μg induce maximal hyperemia while contrast medium induce 65% of maximal hyperemia. Therefore, FFR measurements with contrast medium is feasible and has better accuracy than restindices compared to FFR. We establish the weak correlation between FFR and angiographic indicesand weakens correlation as risk factors accumulates, especially in diabetic patients. Finally, we described in three studies the method of absolute coronary flow and microvascular resistancesmeasurements based on thermodilution principle with a dedicated infusion catheter. We showed anaccurate measurement with this technique (R=0.98), which induces maximal hyperemia without theneed of hyperemic agent with reproducible measurements in humans (R=0,91).Conclusion The use of invasive coronary flow measurements to study the coronary circulation is essential inclinical practice and in research.

Genetic and environmental protective factors and risks modulate brain structure and function in neurodegenerative diseases and their preclinical stages. We wanted to investigate whether the years of formal education, a proxy measure for cognitive reserve, would influence hippocampal structure in Alzheimer’s disease patients, and whether apolipoprotein Eε4 (APOE4) carrier status and a first-degree family history of the disease would change a possible association. Fifty-eight Alzheimer’s disease patients underwent 3T magnetic resonance imaging. We applied a cortical unfolding approach to investigate individual subregions of the medial temporal lobe. Among patients homozygous for the APOE4 genotype or carrying both APOE4 and family history risks, lower education was associated with a thinner cortex in multiple medial temporal regions, including the hippocampus. Our data suggest that the years of formal education and genetic risks interact in their influence on hippocampal structure in Alzheimer’s disease patients.

There is a trend in Sweden towards increasing the electricity production from renewable energy sources in the electric grid. The increased share of renewables could be seen as essential for Sweden to be able to meet the obligated climate goals. Integration of renewables will enable Sweden to be a progressive part in reducing greenhouse gases and decreasing the global warming. However, one issue with renewable energy sources is the inverter governed production. This, together with the decommission of larger synchronous generators, results in decreasing the inertia and increasing the instability inthe grid.  This thesis is dedicated to elaborating on frequency stability issues and investigating how Variable Speed Wind Turbines (VSWT) could contribute towards stabilized operation when included in frequency support services.  The study is generated through an extensive research process where focus areas are identified. Questions are purposed and then discussed through interviews with experienced people in the field. Estimated power production series from a wind turbine park (WTP) are applied in a constructed model to study the possibilities appearing when  including VSWTs in frequency support services. The income generated from including VSWTs in different regulation power market services is with the model compared against solely procuring the production capacity on the day ahead market. The studied frequency support services are then compared altogether to generate favorable solutions. The study examines both economic as well as technical features of the inclusion of VSWTs in frequency support services.  Results found in the study were that inclusion of wind turbines for power regulation purposes could be seen as increasingly manageable and needed in the electric grid. The maturity of technical solutions alongwith a transition in the regulation power market could be observed as leading factors. The diversification of regulation abilities and the increasing economic incentives in the regulation power market was also found to be important reasons for including wind turbines in the regulation power market. In the study, it was also found thataggregating the power production from several VSWT could increase the ability to deliver the studied services.  It was concluded that inclusion of VSWT in the frequency containment reserve during disturbed operation for down-regulation purposes as well as the fast frequency reserve was the most promising frequency support products for the inclusion of wind turbines. When including battery energy storages and to a larger part managing the durability demands for the services then the frequency contain reserve for normal operation and the frequency containment reserve for disturbed operation for upregulation purposes could be observed as preferable alternatives. Regulation abilities were concluded as achievable with the use of pitch and torque regulation techniques available in the variable speed wind turbine.

My diploma thesis focuses on women in the active reserve. Active reserve has become more popular due to new security threats and increasing need of people to be prepared when something goes wrong. In theoretical part I introduce the basic concepts that my work is based on. I focus on the active reserve from their origin till the nowadays. As for the empirical part, I have done ten semi-structured interviews with the women - members of the active reserve. The goal of this thesis is to find out what motivates the women to enter this primarily male-dominated area. Within my thesis I was also wondering what kind of reactions based on participation in active reserve my informants have to deal with and if there are any advantages or disadvantages connected with being the active reservist. Above all I was interested in personal experience of my informants. The keys words: active reserve, women, motivation, gender, army, interviews, militarization, military forces, army reserve

Objective: Cognitive reserve influences age of onset, speed of progression, and clinical manifestations of Alzheimer’s disease. We investigated whether cognitive reserve interacts with clinical and neuropsychological parameters in mild cognitive impairment (MCI). Methods: In this cross-sectional study, we recruited 273 people (70.6 ± 10.1 years, 54.6% women) suffering from subjective memory complaints (n = 65), MCI (n = 121), or dementia (n = 87). Patients underwent neuropsychological evaluation, laboratory testing, and brain imaging. Additionally, we obtained information on years of education and help-seeking motivation. Results: MCI patients with a university degree were significantly older than those without (71.6 ± 9.6 vs. 66.9 ± 10.3, p = 0.02). University-educated MCI patients demonstrated superior performance in verbal fluency. Intrinsic help-seeking motivation (self-referral) was associated with higher cognitive reserve. Female MCI patients presented with greater intrinsic motivation. Conclusion: Cognitive reserve modulates clinical and neuropsychological measures in patients with MCI.

The Swedish electrical grid has historically been robust and reliable, but with increased electrification in numerous sectors, out-phasing of nuclear power and a high market diffusion of wind power, the system is now facing challenges. The rotational energy in the system is expected to decrease as a result of higher shares of intermittent energy sources, which can affect the stability of the grid frequency negatively. To manage increased frequency drops, the new Fast Frequency Reserve (FFR) market will be implemented by June 2020 in the Nordic power system. Simultaneously, it is expected that the demand of electricity will increase significantly in the transport and industry sectors in the coming years. Several DSOs already today indicate challenges with capacity and power security and have or will implement power tariffs as an economic incentive to prevent these problems. For energy intensive customers, such as industries, it will become important to reduce power peaks to avoid high grid fees. Several peak load shaving strategies can be utilized by industries to reduce their power peaks and thus the power tariff. The aim of this study is to economically analyze peak load shaving for Swedish industries. This is done using Li-Ion BESS and DSM, and to maximize the utilization of the BESS by including energy arbitrage and FFR market participation into the analysis. Firstly, a literature review is conducted within the topics of peak load shaving strategies, energy arbitrage and ancillary services. Secondly, data is gathered in collaboration with WSP Systems – Energy, the initiators of the project, to conduct case studies on two different industries. These cases are simulated in the modeling software SAM, for technical analysis, and then economically evaluated with NPV. Also, nine scenarios are created for the emerging FFR market concerning the number of activations per year and the compensation price per activation. The results from the case studies indicate that peak load shaving of 1 – 3 % with BESS provides a positive NPV for both case industries. However, higher percentages result in negative NPVs when no additional revenue streams are included. When considering energy arbitrage, it is concluded that the additional revenues are neglectable for both industries. Participating in the FFR market provides similar trends in the results as before. The exception is valid for scenarios with high numbers of FFR activations and compensation prices, where positive NPVs for all levels of peak load shaving can be concluded. The peak load shaving strategy DSM is implemented for one of the industries, where efficiency measures are concluded to have the most impact on the economic evaluation. If all efficiency measures would be implemented, the electricity consumption would be reduced by 17 %. Additionally, the power peaks would be reduced with 18 % and result in a significantly more positive NPV than peak load shaving using BESS. A sensitivity analysis concerning BESS capital cost and power tariff price concludes that the BESS price has a strong relation to the NPV, where a BESS price reduction of 60 % results in an NPV increase of at least 100 %. BESS prices have decreased the past years and are expected to keep decreasing in the future. Hence, investments in BESS can become more profitable and attractive in the coming years. Finally, for future research, it is recommended to combine the methodology from this study together with a load forecasting method. This combined methodology could then be practically applied to case specific industries with high peak loads. / Det svenska elnätet har historiskt sett varit robust och pålitligt, men i takt med ökad elektrifiering i flera sektorer, utfasning av kärnkraft samt ökad mängd installerad vindkraft ställs nu systemet inför nya utmaningar. Bland annat förväntas rotationsenergin i systemet minska som ett resultat av högre andelar intermittenta energikällor i systemet. För att hantera detta kommer den nya Fast Frequency Reserve (FFR) marknaden finnas tillgänglig från och med juni 2020. Samtidigt förväntas även efterfrågan på el inom transport- och industrisektorn öka markant de kommande åren. Redan idag är effektbrist ett problem i vissa regioner, vilket kan komma att förvärras. Många nätägare ska eller har redan infört effekttariffer för utnyttjande av deras elnät, vilket är ett ekonomiskt incitament för att hantera effektproblematiken där kunder med en mer flexibel elkonsumtion kommer gynnas. För större elförbrukare, som exempelvis industrier, kan det bli ekonomiskt betydelsefullt att sänka sina effekttoppar och därmed undvika höga nätavgifter. För att minska effekttoppar finns ett flertal så kallade peak load shaving-strategier, som kan utnyttjas av industrier för att minska kostnaderna för effekttariffen. Syftet med denna studie är att analysera peak load shaving för svenska industrier, med hjälp av ett Li-Ion batterilagringssystem och efterfrågeflexibilitet, samt maximera utnyttjandet av batteriet genom att inkludera energiarbitrage och deltagande i FFR-marknaden i analysen. Ett första steg i arbetet är att utföra en litteraturstudie för de berörda områdena. I ett andra steg insamlas data tillsammans med WSP, initiativtagaren av projektet, för att kunna göra en fallstudie på två industrier. För dessa fallstudier undersöks de tekniska förutsättningarna för att implementera peak load shaving-strategier genom modellering i simuleringsprogrammet SAM. Sedan utreds de ekonomiska förutsättningarna för fallstudierna, där NPV används som ekonomiskt nyckeltal. Dessutom skapas nio scenarion för den kommande FFR-marknaden för att uppskatta kostnader och inkomster. Resultatet av fallstudien visar att 1 – 3 % kapade effekttoppar med batterilagring ger ett positivt NPV för båda industrierna. Över 3 % blir resultatet negativt utan ytterligare inkomstströmmar inkluderade. Energiarbitrage konstateras att bidra med marginella positiva fördelar. Vid inkludering av FFR-marknaden i analysen erhålls liknande trender i resultaten, bortsett från scenarion med relativt högt antal avrop och pris. I dessa fall blir även 4 – 10 % kapade effekttoppar ekonomiskt attraktiva. För en av industrierna utvärderas efterfrågeflexibilitet, där effektivisering av elkrävande processer har störst inflytande på resultatet. Vid implementering av samtliga effektiviseringsåtgärder skulle elkonsumtionen minska med 17 %. Dessutom minskar effekttopparna med 18 %, vilket resulterar i ett signifikant mer positivt NPV, jämfört med användningen av batterilager. En känslighetsanalys gällande batteripris och effekttariffer, konstaterade att batteripriset har en stark påverkan på NPV. Vid en batteriprisminskning på 60 % ökar NPV med minst 100 %. Därmed kan batteriinvesteringar bli mer gynnsamma och attraktiva om batteripriser fortsätter att falla, vilket flera prognoser indikerar. Slutligen rekommenderas framtida studier att kombinera metodiken från detta arbete med en prognostiseringsmetod för elanvändning i industrier. Denna kombinerade metod kan sedan praktiskt tillämpas på fallspecifika industrier med höga effekttoppar.