No description available.

Páramo ecosystems are unique alpine grasslands found at high altitudes (2000-5000 m a.s.l.) in the Andean mountain range. While they provide a wide range of important ecosystem services, such as organic carbon sinks, protect endemic species, provide agriculture services, act as recreation sites etc., their perhaps most important service is found in their ability to regulate water flows. The unique volcanic soil properties and endemic plant life that resides in these areas have an exceptional ability to capture, regulate and store water. Colombia has the world’s largest stretch of páramo areas, which supply almost the entire country with clean tap water without active filtration initiatives. Currently there are around seven million people living in Bogotá, the main capital. Northeast of the capital, in the Eastern Range of the Colombian Andes, the Chingaza National Park (CNP) is located. In this park, there are approximately 645 km² of páramo ecosystems, which supplies around 80 % of all the tap water used in Bogotá. However, with an expanding population growth and urbanisation, the demand for water is increasing rapidly. The long-lasting conflict within the country has prevented the exploitation of the economical goods belonging to the páramo ecosystems. Recent peace agreements have opened up for international trade, tourism and an expanding industry. However, the lack of regulations, which protect the páramo ecosystems, have now resulted in an increasing pressure of these systems. As such, sustainable adaptation plans are required across multiple stakeholder levels in order to prevent further deterioration of the páramos. Moreover, the anthropogenic climate changes are posing a threat to these fragile environments. An increasing temperature and changing rainfall patterns are expected to affect the hydroclimatic conditions, especially on high altitudes where these ecosystems are located. Nevertheless, the internal and external processes governing these ecosystems are highly complex and the knowledge gaps are many. One reason for this is that the remote and inaccessible locations results in generally scarcely distributed networks of monitoring stations. In this study, CNP was chosen due to the relatively well-monitored network of stations. Long-term temperature, precipitation and runoff data was analysed to identify the hydroclimatic conditions in the park. Regional downscaled precipitation, minimum and maximum temperature simulations under the Representative Concentration Pathways (RCP) 4.5 and 8.5, covering the period 2041-2065 were obtained from the WorldClim 1.4 database. Interpolated historical observations for the same parameters but during the period 1960-1990, covering CNP, were derived from the same database. These interpolated historical parameters were used for establishing upper and lower precipitation and temperature boundaries for where a páramo ecosystem can thrive during future RCP-scenarios. Historically, the hydroclimatic conditions in CNP has been characterised by a high input of water from precipitation, low evapotranspiration due to low temperatures and clouds presence, and a stable and abundant runoff. However, the results from this study suggest increasing temperature and precipitation boundaries during both RCP 4.5 and RCP 8.5 compared to historical interpolated data. Furthermore, there is a tendency towards prolonged and amplified seasons, with wetter wet season and drier dry seasons. When mapping suitable páramo environments under future RCP-scenarios, there is a tendency towards decreasing suitable páramo areas, especially during dry season. However, the findings in this report are merely based on temperature and precipitation parameters. Other forcing factors (ENSO, cloud cover, fog, occult precipitation, land use etc.) that also influence these environments and the ability to adapt to new hydroclimatic conditions, were not investigated. In order to prevent further loss of these environments and their associated ecosystem services, it is recommended to apply modern techniques, such as remote sensing in combination with traditional fieldwork, point samples and hydrological models in future studies.

The diploma thesis describes Climate Change and impacts of Climate Change on the development of the water management analyis of reservoir strorage capacity. The development of climate chang influence on reserviors storage capacity is presented until 2100. It also gives a detailed online downscaling description.

MENVSC (Climatology) / Department of Geography and Geo-Information Sciences / Heat waves are warm extreme temperature events that have environmental and socio-economic impacts in many regions across the world. Negative impacts of warm extreme temperatures over South Africa necessitate the need to study the nature of heat waves. Observations and satellite datasets are analysed in the investigation of the nature and trends of heat waves over South Africa in the present (1983-2012) and future (2010-2039, 2040-2069, 2070-2099) climates. Case study and composite analysis of National Centers for Environmental Prediction datasets were done using the Grids Analysis and Display Systems to get an in-depth understanding of the structure of heat waves in South Africa. Future climate model output obtained from the Conformal Cubic Atmospheric Model was used for future heat wave trends in South Africa. The simulations were made using the Representative Concentration Pathways 4.5 and 8.5. Heat waves are unusual events in the present climate (1983-2012) over much of the country, with 20 of the selected 24 stations experiencing an average of less than one heat wave per season. Heat waves are also more frequent and last longer during warm phase of El Niño-Southern Oscillation (ENSO) than in cool phase of ENSO with the north-east being the most prone region. Composite analysis of 500 hPa omega indicates subsidence over the interior of South Africa in both phases of ENSO. Heat waves in South Africa are localized and associated with a middle level high pressure system that persists over the interior inducing anticyclonic flow and subsidence. The anticyclonic circulation over a region experiencing heat wave weakens with decreasing height over land areas which may be due to frictional forces at the surface and the high is placed further south-east at the surface. Advection of dry continental northerly winds also contributes to high maximum temperatures during heat waves in the interior. Maximum temperatures are expected to increase drastically from the present-day climate to the 2070 – 2099 period, with an average increment of about 8°C during DJF in much of the central interior. As a result, heat wave occurrences are expected to be higher in the future warmer climates when climate change signal is higher. Most increases are expected for heat waves lasting for a week than those lasting for over 2 weeks. CCAM outputs also indicated that heat waves in South Africa are expected to last longer and become more intense during the future warmer climates. Longer lasting and more intense heat waves are expected over the Karoo than in other parts of the country.

Jordens temperaturökning ökar genom utsläpp av växthusgaser. Ökningen smälter inlandsisarna och Antarktis samt expanderar havet vilket höjer havsnivån och påverkar erosion. Denna havsnivåhöjning med tilläggande stormar höjer havsnivån markant och påverkar kustkommuner. Olika RCP scenarion är framtagna för att förutse hur framtiden kommer att se ut år 2100. Vilken av RCP scenarion som kan inträffa beror på hur klimatpolitiken och utsläppen fortskrider. Syftet är att skapa ett kunskapsunderlag för Halmstad kommun med föreslagna naturbaserade klimatanpassningsåtgärder utmed kusten. Arbetet fokuseras på omvärldsanalys, vilket genomförts i form av intervjuer från kustkommuner och litteraturstudie från rapporter. Naturbaserade klimatanpassningsåtgärder har funktionen att skydda mot havshöjning och erosion men ökar även biologisk mångfald samt skapar rekreation. Redovisade åtgärder är sandstaket, ålgräs, vegetation på strandplanet, klitterövergångar och kustnära våtmarker. Genom att introducera dessa åtgärder skyddas kusten genom att de binder sand, skapar dynor, stärker dynor från nedtrampning och minskar vågenergin. Åtgärdernas för- och nackdelar, kostnad, underhåll, effekt och risker sammanfattas i en avslutande tabell. Genom att analysera Halmstads kust i erosion och havshöjning grundas rekommendationer till föreslagna åtgärder. Implementering av ätgärderna efterfrågar noga studier i lokala förutsättningar för att åtgärden ska nå sin fulla funktion. Kommunens arbete med att genomföra klimatanpassningsåtgärder berör flera aktörer vilket gemensamhetsanläggningar rekommenderas som en del i det strategiska arbetet. Gemensamhetsanläggningar skapar finansieringslättnader genom att fler bekostar åtgärden och ökar samverkan i kommunen, vilket gynnar kommunens framtidsvision med att nå 150 000 invånare år 2050.

This master thesis examines how buildings should be designed in the future, in terms of facades and cooling systems, in order to achieve desired indoor temperatures. The basis of the thesis is the expected increase in outside temperature, due to climate change, and the fact that several hundred people died in 2018, as a result of the heat wave that was in Sweden that year. To examine future indoor temperatures, a model of an apartment building in southern Stockholm was created in the software IDA Indoor Climate and Energy, IDA ICE, as well as future climate files for the same geographic position. The climate files were based on future climate scenarios and local data, in order to be as realistic as possible. The model of the building was simulated during the summer months, beginning of June to end of August, with the focus of receiving the indoor temperatures for year 2030 and 2060. For the year 2060 a sensitivity analysis was made in order to see how a change in building design, to analyze how it may affect the indoor temperatures.The results indicates that the indoor temperatures will continue to increase, as a result of the climate change, and that building design played a small role in lowering the indoor temperatures when it comes to changes in facades, but a bigger role for cooling systems. Peaks of 33°C for the year 2060 was lowered to 25°C when cooling systems where implemented, while changes in facades only lowered the peaks to 32°C.The conclusion for this master thesis is therefore that when it comes to buildings in the future, cooling systems should be considered, as well as changes in the facades, in order to achieve desired indoor temperature. Solar film on the windows and awnings can be used to reduce the indoor temperature, but the balance between daylight admission and heat transmission is important to consider. Rotation of the building and the presence of shading objects, such as balconies and surrounding buildings, also affect the indoor temperature in apartment buildings and should therefore be considered in new construction.

Investigations detailed in this thesis constitute a part of the continuing programme of research undertaken in our laboratory on the riboflavin carrier protein (RCP) with partic­ular reference to identification and synthesis of neutralizing antigenic determinants, design of relevant epitope mimetics with improved immunogenic characteristics and relationship between their secondary structures and immunological properties. The riboflavin carrier protein is elaborated as a reproductive stratagem to ensure ade­quate vitamin deposition in the developing oocyte in the chickens. The protein is scrupu­lously conserved through evolution in terms of physico chemical and immunological char­acteristics from fish through birds to mammals, including primates. In rodents and sub­human primates immunization with the heteroantigen viz., chicken egg white RCP leads to functional neutralization of the endogenous maternal protein resulting in curtailment of early pregnancy. Thus, the crucial role of RCP in maintenance of pregnancy is established and the protein identified as a potential candidate vaccine for immimocontraception. Fur­ther studies with the reduced and carboxymethylated (RCM) RCP as the immunogen re­veal that antibodies induced by RCM-RCP are equally effective in bioneutralization of the endogenous protein. So it can be surmised that the native folded structure of RCP is not obligatory for eliciting bioneutralizing antibodies. In an attempt to identify functionally relevant regions of the protein, a panel of monoclonal antibodies (MAbs) have been raised and characterized. One of the MAbs viz., 6J32Ci2 could bring about early fetal resorp-tion when injected to mice with confirmed pregnancies. These results prompted a detail molecular immunological approach to understand underlying mechanisms. The principal aims of the present investigations include: (1) identification of neutralizing epitopes; (2) synthesis of peptidyl sequences incorporating these determinants; (3) an understanding of the structure, antigenic and immunogenic characteristics of these peptides; (4) correlation of conformational and antigenic characteristics; (5) rational design and synthesis of peptide analogs with greater propensity to assume predicted secondary structures; (6) analysis of conformation dependency of peptide antigens and the importance of such conformation in generating an optimal B-cell response; (7) the efficacy of the antibodies elicited by these Peptide antigens in neutralizing endogenous protein with the ultimate aim of designing synthetic vaccines. Chapter 1 of this thesis deals with a general introduction summarizing the current status of knowledge regarding the chemistry and biology of RCP as well as synthetic pep­tides as potential immunogens. Chapter 2 outlines details of the experimental procedures adopted. Chapter 3 describes the results of investigations on the C-terminal fragment (residues 200-219) of cRCR The main consideration in selecting this sequence for the design of a potential peptide-based vaccine relied on the epitopic specificity of the neu­tralizing MAb 6S2C12. Epitope mapping using the Pepscan method revealed that the monoclonal antibody recognizes a core sequence corresponding to residues 203-210 of the cRCP. A 21-residue synthetic peptide (C-21) comprising this epitope was synthesized and antibodies elicited to the peptide conjugated to two different carriers, namely diphtheria toxoid and purified protein derivative (PPD) for T-cell help. In both active and passive immunoneutralization experiments, the peptide specific neutralizing antibodies interfered with the biological function of the protein and hence either protected from pregnancy or caused early fetal resorption in rodents as well as in sub-human primates. The conforma-tional properties of the peptide in aqueous buffers were analyzed from circular dichroism which revealed the absence of any ordered structure in the native C-21 peptide. Theoreti­cal predictions of secondary structure suggested a propensity for an t*-helical structure for this fragment in the native protein. Therefore, influence of the helix-promoting solvent, vizM 2,2,2,trifluroethanol (TFE) on the C-21 peptide was investigated. Addition of TFE resulted in spectral changes with negative bands at 208 and 222 nm and a positive band at 190 rim which are typical of an a-helix. To gain more information on the conformational characteristics of this peptide, it was considered worthwhile to stabilize the native peptide in an a-helical conformation based on simple rational design principles. Towards this end, four analogs of the parent peptide were synthesized and helix stabilization was sought to be achieved by introducing either salt bridges or back-bone conformational constraints such as by incorporating a-amino isobutyric acid at appropriate positions. In all the analogs, the core sequence, recognised by the neutralizing MAb 6B2C12 was maintained intact to ensure induction of antibodies capable of recognizing the native protein. CD spectral analysis of the analog peptides indicated that all the engineered peptides had varying degrees of enhanced helicities as compared to the parent peptide. The immunogenicity of each analog was studied by to the relevant peptide-diphtheria toxoid conjugates and analyzing their reactivities with the native protein by direct and competitive ELISA. The results revealed that these engi­neered conformational analogs axe highly immunogenic eliciting high titers of anti-protein antibodies. The relative affinities of these antibodies to bind cRCP were investigated. The antibodies to peptide analogs had higher affinities for the native protein and a positive correlation was found between the helical content of the peptide antigen in question and the relative affinity of corresponding antibody. The antibodies directed to all the peptide analogs could block the function of RCP resulting in early embryonic resorption when ad­ministered to pregnant mice. An interesting pattern of immunological cross-reactivity has been observed with the native and designed peptides. Antibodies raised to constrained helical analogs could bind the C-21 peptide which is structurally flexible. In contrast, the antibodies raised to the flexible native peptide antigen were inefficient in recognizing the structured peptides. The ability of all the peptide antibody to bind the native protein has been interpreted in terms of a conformationally flexible C-terminus region in cRCP. Chapter 4 details investigations on a 21-residue peptide (N- 21) from the N-terminiis (4-24) of the protein. Selection of this peptidyl sequence relied on theoretical prediction of potential sequential determinants on RCP other than at C-terminus as well as on the outcome of immunoneutralisation experiments using antibodies to egg yolk RCP which lacks the relevant C-terminal determinants. The structure of this peptide in solution was analyzed by two dimensional NMR and CD. NMR experiments revealed the presence of two structured regions in the peptide. Diagnostic nuclear Overhauser effects characteristics of reverse turns or short frayed helical segments over residues 3-9 and 18-21 of the peptide were obtained. CD spectra showed the presence of a strong, negative band at 204 nm over a wide range of solvent conditions, a feature which has been interpreted in terms of a "polyproline Il-like" segment encompassing residues 11-16 which corresponds to an interesting (X-Pro)^ repeat in the N-21 sequence. Specific antibodies were generated to this peptide as a conjugate with diphtheria tox­oid. Administration of the antipeptide antibodies could neutralize the protein in vivo as demonstrated by early embryonic loss in pregnant mice. In limited experiments the anti­peptide antibodies showed propensity to protect bonnet monkeys from pregnancy over a few consecutive ovulatory cycles when titres are maintained elevated by periodic boosting. To address the relationship between peptide structures and antigenicity, epitope mapping of this antipeptide antibodies as well- as the polyclonal antibodies to native RCP was undertaken using the Pepscan method. The results reveal that antigenic regions correspond well to conformationally well-defined elements of structure with the polyproline II-like seg­ment being a common antigenic determinant on both the peptide and the native protein. These observations are suggestive of the involvement of both the N and C-terminal regions of RCP in terms of its binding to putative plasma membrane receptors.

No description available.

The use of recycled concrete aggregates (RCA) has gained increased attention in the past few decades as an alternative to decrease the carbon footprint of concrete construction. Yet, most of the research performed so far demonstrates that RCA concrete displays inferior performance in the fresh and hardened states when compared to conventional concrete (CC). The latter is believed due to the fact that very often the different microstructure of RCA is not accounted for while the mix-proportioning of RCA concrete. Recently, a number of mix-design procedures accounting for RCA microstructure have been proposed. Amongst them, the Equivalent Volume (EV) method seems to be quite promising. The EV method may proportion RCA concrete made of coarse (CRCA) or fine (FRCA) RCA and is based on a companion CC. Previous research has demonstrated that the fresh and hardened properties of EV mix-designed CRCA are suitable for structural applications. Yet, very few research, analysis and quantification have been conducted on the fresh behaviour of EV mix- proportioned FRCA concrete. This work presents a comprehensive study on the rheological behaviour of EV mix-designed CRCA and FRCA concrete presenting distinct features (i.e. inner qualities, mineralogy, fabrication process, etc.) through the use of a planetary rheometer (IBB). Results show that the EV is capable of proportioning low embodied energy CRCA and FRCA concrete with shear thinning profiles. The latter suggests that these mixtures are suitable for applications under high torque regimes such as vibrated or pumped concrete.

L’objectif de cette recherche doctorale est de décrire et comprendre les effets de la programmation informatique sur l’apprentissage et la mobilisation de compétences d’élèves du primaire. Notre intérêt pour ce phénomène se justifie sous deux considérations : d’abord, la programmation est une activité qui a connu une démocratisation au cours des dernières années, notamment dans le milieu scolaire. Puis, en ce qui concerne la résolution collaborative de problèmes (RCP), il s’agit de compétences appartenant à ce que certains appellent les compétences du 21e siècle (voir notamment Chalkiadaki, 2018; van Laar et al., 2017), et que d’autres appellent les compétences du futur (Conseil des compétences futures, 2020; Gouvernement du Canada, 2020). Les recherches empiriques menées en contextes authentiques de classe sont très peu nombreuses dans la littérature (Lye et Koh, 2014), ce qui atteste pour nous la nécessité de porter un regard contemporain et imprégné des nouvelles tendances technopédagogiques sur ce phénomène d’envergure internationale. Les principaux référents conceptuels sont associés au champ de l’apprentissage collaboratif à l’aide de l’ordinateur (en anglais le Computer-supported collaborative learning, CSCL), un champ dont nous citons plusieurs travaux réalisés dans les années 1990 (Koschmann et al., 1996; Scardamalia et Bereiter, 1994). Il nous a permis d’aborder les aspects techniques (programmation, ordinateur), sociaux (interactions, médiatisation) et pédagogiques (apprentissage, développement de compétences) du phénomène que nous souhaitions étudier. À l’aide d’un devis qualitatif et interprétatif de type étude de cas multiples, nous avons mis en place un scénario pédagogique dans trois écoles primaires au Québec. Amenant les élèves à découvrir graduellement les concepts fondamentaux de la programmation informatique, le scénario Deviens un maître NAO mise sur la programmation visuelle et tangible pour mobiliser, voire développer, un ensemble d’habiletés et de compétences, tant transversales que disciplinaires. Une série de 20 niveaux sont proposés aux élèves, qui doivent réaliser des programmes ayant pour but d’animer un robot humanoïde nommé NAO. Le premier cas a été observé dans une école alternative de Montréal. Les élèves (n=29) ont été séparés en équipes multiniveau, ce qui a amené la collaboration d’élèves d’âges et de niveaux scolaires différents. Les cas 2 à 5 ont été étudiés dans une école de Montréal et présentent des élèves de quatrième, cinquième et sixième année (n=70). Enfin, le dernier cas se situait dans une classe de cinquième année de la grande région de Québec (n=10). Plusieurs de ces élèves ont des difficultés d’apprentissage ou sont en situation de handicap. Nous avons observé les pratiques effectives de programmation ainsi que la mobilisation des compétences de RCP à l’aide d’un appareillage méthodologique considérable : (a) une caméra filmant l’activité des élèves dans leur environnement immédiat, (b) la caméra intégrée de l’ordinateur qui filmait le visage des élèves et leurs interactions verbales, et (c) l’enregistrement de l’écran d’ordinateur que les élèves utilisaient pour faire la programmation visuelle et tangible du robot NAO. Nous avons ensuite utilisé ce corpus de données vidéos pour déterminer une typologie des pratiques effectives de programmation d’élèves du primaire, pour créer une grille d’observation de la RCP à partir d’observations empiriques et authentiques et pour comprendre le processus de RCP dans le cadre d’une activité de programmation au primaire. Parmi les principaux résultats, nous proposons une typologie des pratiques de programmation visuelle fortement basée sur nos observations empiriques, ce qui l’ancre fortement dans la réalité du terrain de recherche. Puis, nous avons également été en mesure de concevoir une grille d’observation de la RCP en nous appuyant sur les travaux scientifiques antérieurs et, surtout, sur nos observations empiriques. Cette grille, présentant 3 dimensions et 15 indicateurs, permet d’observer les processus et habiletés mis en œuvre par les élèves de façon collaborative. Enfin, l’utilisation de cette grille a mené à l’analyse systématique et compréhensive de la façon dont les élèves parvenaient à compléter les activités de programmation de façon collaborative. Nous soulignons d’une part la prépondérance de certaines habiletés (échanges à propos du problème, attribution explicite ou implicite des rôles, vérification des solutions, etc.), et d’autre part la faible mobilisation d’habiletés comme l’adaptation des interventions, l’identification des forces et des faiblesses et la vérification des actions. / The objective of this doctoral research is to describe and understand the effects of computer programming on the learning and mobilization of skills of elementary school students. Our interest in this phenomenon is justified by two considerations: first, programming is an activity that has been democratized in recent years, especially in the school environment. Second, with respect to collaborative problem solving (CPS), these are skills that belong to what some call 21st century skills (see, for example, Chalkiadaki, 2018; van Laar et al., 2017), and others call future skills (Future Skills Council, 2020; Government of Canada, 2020). Empirical research conducted in authentic classroom contexts is very scarce in the literature (Lye and Koh, 2014), which attests to the need for us to take a contemporary look at this international phenomenon, infused with new techno-pedagogical trends. The main conceptual referents are associated with the field of Computer-supported collaborative learning (CSCL), a field from which we cite several studies conducted in the 1990s (Koschmann et al., 1996; Scardamalia and Bereiter, 1994). It allowed us to address the technical (programming, computer), social (interactions, mediatization) and pedagogical (learning, skill development) aspects of the phenomenon we wanted to study. Using a qualitative and interpretative multiple case study design, we implemented a pedagogical scenario in three elementary schools in Quebec. By gradually introducing students to the fundamental concepts of computer programming, the Become a NAO Master scenario relies on visual and tangible programming to mobilize and even develop a set of skills and competencies, both transversal and disciplinary. A series of 20 levels are offered to students, who must create programs to animate a humanoid robot named NAO. The first case was observed in an alternative school in Montreal. The students (n=29) were separated into multi-level teams, which led to the collaboration of students of different ages and grade levels. Cases 2-5 were studied in a Montreal school and featured students in grades 4, 5, and 6 (n=70). Finally, the last case was in a fifth grade class in the greater Quebec City area (n=10). Many of these students have learning difficulties or disabilities. We observed the effective programming practices as well as the mobilization of CPR skills using a considerable methodological apparatus. Indeed, for each team in each class, we had: (a) a camera filming students' activity in their immediate environment, (b) the computer's built-in camera that filmed students' faces and verbal interactions, and (c) the recording of the computer screen that students used to do the visual and tangible programming of the NAO robot. We then used this video data set to determine a typology of elementary students' effective programming practices, to create a CPS observation grid based on empirical and authentic observations, and to understand, using the created grid, the process of CPS in an elementary programming activity. Among the main results, we propose a typology of visual programming practices strongly based on our empirical observations, which anchors it strongly in the reality of the research field. Then, we were also able to design a CPS observation grid based on previous scientific works and, above all, on our empirical observations. This grid, presenting 3 dimensions and 15 indicators, allows us to observe the processes and skills implemented by the students in a collaborative manner. Finally, the use of this grid led to a systematic and comprehensive analysis of the way in which students managed to complete programming activities in a collaborative manner. On the one hand, we note the preponderance of certain skills (exchanges about the problem, explicit or implicit assignment of roles, verification of solutions, etc.), and on the other hand, the weak mobilization of skills such as adapting interventions, identifying strengths and weaknesses, and verifying actions.