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Animals who live in the high-altitude environment are faced with the harsh conditions of low oxygen availability. This can make it difficult to perform daily tasks that require aerobic metabolism. However, deer mice (Peromyscus maniculatus) have evolved physiological adaptions that allow populations to survive in the high-altitude environment. One activity important for survival is aerobic locomotion and the rapid recovery of muscle metabolism after a bout of exercise. Hypoxia acclimated high-altitude mice have a greater reliance on carbohydrates to power exercise than low altitude mice and show a significant depletion of muscle glycogen. However, it is unclear how quickly after exercise is finished that these mice can replenish muscle glycogen stores. The gastrocnemius muscle of high-altitude deer mice has a more aerobic phenotype and a greater capacity to oxidize lipids than in low altitude mice. This suggests that high altitude mice may recover more quickly from exercise than their lowland counterparts due to a greater capacity to power glycogen replenishment through aerobic metabolism using the lipids stored in muscle as intramuscular triglycerides (IMTG). Using low- and high-altitude native deer mice born and raised in common lab conditions and acclimated to chronic hypoxia, I determined changes in oxygen consumption (VO2) following aerobic exercise and sampled skeletal muscle at various time points during recovery to examine changes in key metabolites, including glycogen and IMTG. I found there was depletion in glycogen stores during exercise in lowlanders and glycogen did return to resting levels following 90 minutes of recovery. In contrast, IMTG’s did not significantly change with exercise or during the recovery period in either population. These data suggest that muscle recovery from aerobic exercise may be influenced by altitude ancestry in deer mice. / Thesis / Master of Science (MSc)

A phytosociological study covering approximately 12 000 km2 was completed within Southeastern Mpumalanga high altitude grasslands. The towns of Belfast, Barberton, Piet Retief and Wakkerstroom represented the four corners of the area. The study formed part of the Grassland Biome Project sponsored by the Department of Environmental Affairs and Tourism. The Braun-Blanquet approach was applied. Grassland research results from the western side of the country, determined that soil patterns and vegetation distribution are significantly correlated. Based on these results, it was hypothesised that the same correlation would exist in the east. The eight soil patterns used during the survey as homogenous units, were Ab, Ac, Ad, Ae, Ea, Fa, Fb and lb. A pro rata, randomly stratified sample size of 405 plots were used. An in-depth literature study of the environmental and other factors related to vegetation distribution, indicated on local scale that a significant correlation exists between landform and plant distribution. Two geographic information systems, Idrisi and Arc-Info/Niew, aided in the modelling and extraction of environmental attributes from existing databases. A TWINSPAN classification of the complete floristic data set falsified the null hypothesis based on the soil patterns but verified the null hypothesis based on landforms. The TWINSPAN dendrogram revealed clusters associated with three landforms (mountains, hills and lowlands, and plains) in two ecosystems, the terrestrial and the wetlands or aquatic. The three landforms represented three mapping units: Southeastern Mpumalanga Mountain Vegetation Type, Southeastern Mpumalanga Hills and Lowland Vegetation Type and Southeastern Mpumalanga Plain Vegetation Type. A second TWINSPAN classification was executed on each of the vegetation types. The resulting clusters were tested for uniqueness and informational value using a set of criteria. Those clusters which qualified were arranged in a Braun-Blanquet table to determine communities, sub-communities and variations using constancy and fidelity values. The plant communities within the vegetation types were described in terms of floristic composition and environmental attributes. The indirect gradient analysis ordination program DECORANA was used to determine environmental trends and was confirmed by using multiple regression. Soil water availability was the most significant environmental trend between the two ecosystems and within the communities of the ecosystems in each vegetation type. Soil water availability is influenced by numerous factors, whose significance differs from one vegetation type to another. lt was concluded from this study that, in high rainfall areas, soil patterns and vegetation distribution are not significantly correlated but that landforms and vegetation distribution are significantly correlated. Landscape slope configuration or landform influences soil water availability through soil characteristics (rockiness, texture and depth) and local climatic conditions (aspect, perpendicular insolation and precipitation). lt is suggested that the current Grassland - Savanna Biome boundary be changed towards the west using the boundary between the covered and exposed shields. This suggestion is supported by the presence of Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberiana communities to the east of the study area in the different vegetation types which correlate significantly with the thorntree-tall grass savanna formation on a global scale. AFRIKAANS : 'n Fitososiologiese studie is gedoen van die Suid-oostelike Mpumalanga hoe liggende grasveld tussen die dorpe Belfast, Barberton, Piet Retief en Wakkerstroom. 'n Area van ongeveer 12 000 km2 is bestudeer. Die studie is deel van die Grasveld Bioom Projek gefinansier deur die Departement van Omgewingsake en Toerisme. Die Braun-Blanquet benadering is gebruik. Resultate van grasveldnavorsing in die westelike deel van die grasveld bioom, het aangedui dat 'n betekenisvolle verband tussen grondpatrone en plantegroei verspreiding bestaan. Na aanleiding van hierdie resultate, is die hipotese gemaak dat dieselfde verband in die ooste sal voorkom. Agt grondpatrone, Ab, Ac, Ad, Ae, Fa, Fb, en lb is as homogene eenhede beskou. 'n Eweredige ewekansige steekproefneming van 405 punte is gebruik. 'n Deeglike literatuurstudie van die omgewing en faktore wat verband hou met plantegroei verspreiding, het aangedui op lokale skale, dat 'n verband tussen landvorm en plantegroei verspreiding bestaan. Twee geografiese inligtingstelsels, ldrisi en Arc-lnfo/View, is gebruik in die modelering en verkryging van omgewings data vanuit bestaande databasisse. 'n TWINSPAN klassifikasie gebaseer op die volledige spesiesamestelling, het die nul hipotese oor die grondpatrone ongeldig verklaar maar die nul hipotese oor die landvorme bevestig. Die TWINSPAN dendrogram het groeperings bevat wat verband hou met drie landvorme (berge, heuwels en laaglande en vlaktes) in twee ekosisteme, terrestrieel en vleiland van akwatiese omgewings. Die drie landvorme is beskou as drie karteerbare eenhede: Suid-oostelike Mpumalanga Berg Plantegroeitipe, Suidoostelike Mpumalanga Heuwels en Laagland Plantegroeitipe en Suid-oostelike Mpumalanga Vlakte Plantegroeitipe. 'n Tweede TWINSPAN klassifikasie is op elk van die plantegroeitipes toegepas. Elke plantegroeitipe se groeperings is met behulp van bepaalde voorwaardes vir uniekheid en inligtingswaarde getoets. Die groeperings wat gekwalifiseer het, is met behulp van konstantheids en getrouheids waardes in 'n Braun-Blanquet tabel gerangskik in gemeenskappe, sub-gemeenskappe en variasies. Elke plantegroei tipe se gemeenskappe is beskryf in terme van floristies spesiesamestelling en omgewingsfaktore. 'n indirekte gradientanalise ordeningsprogram DECORANA is gebruik vir die bepaling van omgewings tendense en is bevestig met behulp van veelvuldige regressies. Grondwaterbeskikbaarheid was die mees betekenisvolle omgewingstendens tussen die ekosisteme en die gemeenskappe van die plantegroei tipes. Grondwaterbeskikbaarheid word deur 'n aantal faktore beïnvloed, waarvan die belangrikheid van plantegroei tipe tot plantegroeitipe wissel. 'n Gevolgtrekking van die studie is, dat in hoë reënvalomgewings daar nie 'n betekenisvolle verband is tussen grondpatrone en plantegroei verspreiding nie maar wel tussen landvorme en plantegroeiverspreiding. Landskap hellingsamestelling of landvorme beïnvloed grondwaterbeskikbaarheid deur middel van grondeienskappe (klipperigheid, tekstuur en diepte) en lokale klimaatstoestande (aspek, loodregte bestraling en presipitasie). Daar word voorgestel dat die huidige Grasveld- Savanna Bioom grens weswaarts geskuif word om ooreen te stem met die grens tussen die bedekte en blootgestelde plate. Die voorstel word ondersteun deur die teenwoordigheid van Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberana plantgemeenskappe in die ooste van die plantegroeitipes wat betekenisvol ooreenstem met die langgras-doring boom savanna formasie op globale skaal. / Dissertation (MSc)--University of Pretoria, 1999. / Plant Science / unrestricted

High altitude is one of the most extreme environments inhabited by endotherms, where extreme cold temperatures and low O2 availability (hypoxia) can constrain aerobic heat production (thermogenesis) to maintain body temperature (Tb). Recent findings suggest that the gut microbiome contributes to whole-body thermogenesis, but the significance of this mechanism for coping in cold environments is unknown. We examined whether the gut microbiome contributes to adaptive variation in thermogenic performance in deer mice at high altitude. Mice from populations native to high altitude and low altitude were born and raised in common conditions. Adults from both populations were acclimated to warm (25C) normoxia or cold (5C) hypoxia (~12 kPa O2 for 6 weeks) in a full factorial design, and a subset of mice in each group were treated with antibiotics to deplete the gut microbiome. Thermogenic endurance was then measured as the duration that Tb and metabolism could be maintained during acute cold challenge. In lowlanders, antibiotics had only modest effects on thermogenic endurance. In highlanders, in stark contrast, antibiotic treatment led to pronounced reductions in thermogenic endurance in both environments. These effects could not be explained by impairments in aerobic heat production by host thermogenic tissues, because antibiotic treatment had no effects on cold-induced increases in O2 consumption or UCP1 content of brown adipose tissue. These results suggest that the gut microbiome plays an increased role in thermogenesis in high-altitude mice. Thermogenic performance contributes to fitness at high altitude, suggesting that changes in host-microbe interactions contribute to high-altitude adaptation. / Thesis / Master of Science (MSc) / High altitude is one of the most extreme environments inhabited by endotherms. Recent findings suggest that the gut microbiome contributes to thermogenesis, but the significance of this mechanism for coping in cold environments is unknown. We examined whether the gut microbiome contributes to adaptive variation in thermogenic performance in deer mice at high altitude. Adult mice from low and high-altitude populations were acclimated to warm normoxia or cold hypoxia, and a subset of mice in each group were treated with antibiotics to deplete the gut microbiome. Thermogenic endurance was measured as the duration that Tb and metabolism could be maintained during acute cold challenge. In lowlanders, antibiotics had modest effects on thermogenic endurance but in highlanders, it led to pronounced reductions in thermogenic endurance in both environments. These results show that thermogenic performance contributes to fitness at high altitude, suggesting that changes in host-microbe interactions contribute to high-altitude adaptation.

The New World Junonia butterflies include well-studied model organisms yet their phylogeny remains unresolved by traditional cox1 DNA barcodes. Sixteen Junonia mitochondrial genomes were sequenced using next generation MiSeq technology. Junonia lemonias, an Old World species, has mitochondrial genome features typical of Ditrysian Lepidoptera, and synteny is maintained throughout Junonia. Analysis of Junonia mitogenomes produced a robust phylogeny that was used with biogeographic information to infer that Junonia crossed the Pacific Ocean to invade the New World on 3 separate occasions. Junonia vestina, a high elevation species from the Andes Mountains, shows high altitude adaptation in the mitochondrial protein coding loci atp6, atp8, cox1, cob, nad1, and nad2, with the strongest effects seen in cox1 and nad1. There is some overlap between these genes with human loci that have disease associations with the same amino acid positions which could help elucidate the function of high elevation mutations in J. vestina. / February 2016

The high altitude balloon operations at Esrange Space Center have been goingon since 1972, and about 550 launches have been performed. Their present service system for the high altitude balloons is about 18 years old. To be able to meet the requests from their customers, SSC have started the development of a new service system. A service system contains all features and technology required to perform a high altitude balloon mission. This system is separated from the payload. Important design aspects for the new service system have been investigated to be able to leave recommendations to SSC. These are frequency for the radio communication, modulation scheme for the communication link, prevention of corona discharge, and available computer systems to be used as on-board computers. These design aspects have been evaluated according to the requirements for the development project. Theory, articles, available standards and analyzes have been read and evaluated to reach a conclusion about these subjects. It was found that the best frequency bands are the 400MHz-band, downlink, and the 450MHz-band, uplink. The operation in these bands will be unmodified for many years, and the link suffers little loss. The 2.3GHz-band is interesting from an international perspective, and it is suggested that SSC work to get a band dedicated to aeronautical services in this band. The best modulation scheme for the service system is GMSK, as it has very good spectral eficiency. The corona discharge can only be prevented indirect by SSC, as the phenomena occurs within or between components, aspects which SSC can't control. Standardized methods for tests and specications lists was suggested to minimize the risk of a discharge. The best computer system is an in-house designed service system that have been used on sounding rockets. It fits the present requirements the best. It suggested that the Beaglebone Black should be implemented in basic systems, providing processing and storage via simple serial communication, as it is a very cost eficient solution.

The institution of Engineering Sciences at Uppsala University in cooperation with Umeå University is working on a project where they will examine the decision-making in extreme situations. A part of this project is to investigate leadership in high altitudes expeditions. This report will discusses the type of leadership used in high altitudes expeditions. Then, to examine how well you can use it in companies and organizations, and the ability to prevent company’s disasters with this kind of leadership. This is done by studying different company’s stories, where they gone bankrupt or fallen into a deep crisis. This is done to find out if high altitude leadership, which is the type of leadership used in high altitudes expeditions, can prevent the end of companies or organizations got. The report contains the conclusions I have drawn from HAL (high altitude leadership) in the different stories. They include the parts of HAL that is interesting and the conclusion that it may be better to use it as a leadership tool than a type of leadership.

In this thesis, we consider maximized power allocation of non-orthogonal multiple ac- cess (NOMA) schemes since it outperforms than orthogonal multiple access (OMA) for the high altitude platform networks (HAPNETs) both in the back- haul and access links. Secondly, we propose a cluster formation (CF) algorithm and power-bandwidth resource allocation (PB-RA) for solving the resource management of HAPNETs. We adopt the particle swarm optimization (PSO) algorithm to explore the optimal de- ployment of high altitude platforms (HAPs) and unmanned aerial vehicles (UAVs) iteratively by a given swarm size. By PSO, we provide the best deployment under a given iteration number. Besides that, numerical results show that the NOMA schemes have better performance than OMA ones concerning different network control factors like the number of BSs, HAPs, and UAVs.

Carta al editor / Revisión por pares

Introduction: Nitric oxide (NO) is an integral molecule implicated in the control of vascular function. It has been suggested that vascular dysfunction may lead to the development of acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE), though data to date remains scarce. Therefore, there is a clear need for further work to address the role of NO in the pathogenesis of high-altitude illness. Aims: There were two primary aims of the current work: (1) To examine whether hypoxia mediated changes in systemic NO metabolism are related to the development of AMS and sub-clinical pulmonary oedema and (2) to examine whether hypoxia mediated changes in the trans-cerebral exchange kinetics of NO metabolites are related to the development of AMS and headache. Hypothesis: We hypothesise that hypoxia will be associated with an increase in reactive oxygen species (ROS) formation, resulting in a decrease in vascular NO bioavailability (O2•- + NO → ONOO•-, k = 109 M.s-1). The reduction in NO will lead to vascular dysfunction and impaired oxygen (O2) delivery. Subsequent hypoxaemia will result in pulmonary vascular vasoconstriction and the development of sub-clinical pulmonary oedema within and mild brain swelling. Symptoms and reductions in NO bioavailability will be more pronounced in those who develop AMS since they are typically more hypoxaemic. Alternatively, a hypoxia mediated increase in NO, during vasodilatation, specifically across the cerebral circulation, may activate the trigminovascular system resulting in headache and by consequence, AMS. Methods: Study 1 – AMS symptoms, systemic venous NO concentration and nasal potential difference (NPD), used as a surrogate biomarker of extravascular lung oedema, were quantified in normoxia, after a 6hr passive exposure to 12% oxygen (O2) and immediately following a hypoxic maximal exercise challenge (≈6.5 hrs). Final measurements were 2 obtained two hours into (hypoxic) recovery. Study 2 – AMS, radial arterial and internal jugular venous NO metabolite concentrations and global cerebral blood flow (CBF), using the Kety-Schmidt technique, were assessed in normoxia and after a 9hr passive exposure to 12.9% O2. AMS was diagnosed if subjects presented with a combined Lake Louise score of ≥5 points and an Environmental Symptoms Questionnaire – Cerebral score of ≥0.7 points. Results: Hypoxia was associated with a reduction in total plasma NO, primarily due to a reduction in nitrate (NO3•) and a compensatory increase in red blood cell (RBC)-bound NO(P < 0.05 vs. normoxia) in both studies. Study 1 – Exercise reduced plasma nitrite (NO2•) (P< 0.05 vs. normoxia) whereas RBC-bound NO did not change. NO was not different in those who developed AMS (AMS+) compared to those who remained comparatively more healthy (AMS-) (P < 0.05). NPD was not affected by hypoxia or exercise and was not different between AMS+ and AMS- (P > 0.05). Study 2 – Hypoxia decreased arterial concentration of total plasma NO due primarily to a reduction in NO2•- and nitrate (NO3•-). Hypoxia did not alter the cerebral metabolism of RSNO, whereas the formation of RBC-bound NO increased. Discussion: These findings suggest that alterations in systemic or trans-cerebral NO metabolism are not implicated in the pathophysiology of AMS or sub-clinical pulmonary oedema. However, hypoxia was associated with an overall reduction in the total NO pool (NOx), whereas, selected alterations in more vasoactive NO metabolites were observed. Reductions in the partial pressure of O2 (pO2) were thought to be a key regulator in these changes. Overall net increases in RBC NO and corresponding reductions in plasma NO2• in the face of no alterations in NOx indicates that rather than being simply consumed, NO is reapportioned to other NO metabolites and this may be implicated in the pathophysiology of AMS.