Background: ST-elevation acute myocardial infarction (STEMI) represents one of the leading causes of death. The time of STEMI onset has a circadian rhythm with a peak during diurnal hours, and the occurrence of STEMI follows a seasonal pattern with a salient peak of cases in the winter months and a marked reduction of cases in the summer months. Scholars investigated the reason behind the winter peak, suggesting that environmental and climatic factors concur in STEMI pathogenesis, but no studies have investigated whether the circadian rhythm is modified with the seasonal pattern, in particular during the summer reduction in STEMI occurrence. Methods and Results: Here, we provide a multiethnic and multination epidemiological study (from both hemispheres at different latitudes, n=2270 cases) that investigates whether the circadian variation of STEMI onset is altered in the summer season. The main finding is that the difference between numbers of diurnal (6:00 to 18:00) and nocturnal (18:00 to 6:00) STEMI is markedly decreased in the summer season, and this is a prodrome of a complex mechanism according to which the circadian rhythm of STEMI time onset seems season dependent. Conclusions: The “summer shift” of STEMI to the nocturnal interval is consistent across different populations, and the sunshine duration (a measure related to cloudiness and solar irradiance) underpins this season-dependent circadian perturbation. Vitamin D, which in our results seems correlated with this summer shift, is also primarily regulated by the sunshine duration, and future studies should investigate their joint role in the mechanisms of STEMI etiogenesis.

Time series data are of great importance for monitoring vegetation phenology in the dry sub-humid regions where change in land cover has influence on biomass productivity. However few studies have inquired into examining the impact of rainfall and land cover change on vegetation phenology. This study explores Seasonal Trend Analysis (STA) approach in order to investigate overall greenness, peak of annual greenness and timing of annual greenness in the seasonal NDVI cycle. Phenological pattern for the start of season (SOS) and end of season (EOS) was also examined across different land cover types in four selected locations. A significant increase in overall greenness (amplitude 0) and a significant decrease in other greenness trend maps (amplitude 1 and phase 1) was observed over the study period. Moreover significant positive trends in overall annual rainfall (amplitude 0) was found which follows similar pattern with vegetation trend. Variation in the timing of peak of greenness (phase 1) was seen in the four selected locations, this indicate a change in phenological trend. Additionally, strong relationship was revealed by the result of the pixel-wise regression between NDVI and rainfall. Change in vegetation phenology in the study area is attributed to climatic variability than anthropogenic activities.

Die Fischfauna der Mongolei umfasst 64 Arten, von denen aktuell in der Roten Liste elf Arten als regional bedroht und vier Arten als potentiell bedroht eingestuft werden. Eine der wichtigsten Ursachen für den Rückgang der Arten ist der Gold-Tagebau. Viele Goldvorkommen lagern in alluvialen Sedimenten der Fließgewässerauen und werden durch großflächigen Abbau und mechanische Auswaschungsprozesse gewonnen. Dies führt zu erheblichen Störungen im Schwebstoff- und Stoffhaushalt der Fließgewässer und beeinflusst die Habitatverfügbarkeit und -qualität für die Fischfauna. Das primäre Ziel der Arbeit war daher die abiotische und ichthyologische Charakterisierung ausgewählter Referenzgewässer sowie durch Gold-Tagebau beeinflusster Gewässer und die Quantifizierung der Einflüsse des Gold-Tagebaus. Ein weiteres Ziel lag in der Formulierung von angepassten Managementstrategien für eine nachhaltige Entwicklung des expandierenden Bergbausektors in der Mongolei. Die Untersuchungen fanden in den Jahren 2003 bis 2006 an vier rhitralen Gewässern des Khentii-Gebirges im Nord-Osten der Mongolei statt. Die Erfassung der Fischbestände erfolgte mit Hilfe von Elektrofischfanganlagen und Reusen, wobei die vorkommenden Habitate repräsentativ erfasst wurden. Zusätzlich erfolgten Untersuchungen zum Stoffhaushalt der Gewässer und der Gewässersohle. Die relevanten Habitate wurden kartiert und Experimente zum Wanderverhalten ausgewählter Arten durchgeführt. Die Untersuchungen erbrachten folgende wesentliche Ergebnisse: 1. Die Fischfauna der untersuchten Gewässer umfasste 14 Taxa mit überwiegend rhitralen Charakterarten wie Salmoniden, Äschen und Elritzen. Die Fischbestände wiesen eine sehr hohe saisonale Dynamik auf, wobei kleinere Fließgewässer im Herbst verlassen und im Frühjahr neu besiedelt wurden. 2. Der Gold-Tagebau führte zu erhöhten Schwebstoffkonzentrationen und zur Kolmation des hyporheischen Interstitials. Die physikalisch-chemischen Untersuchungen ergaben vor allem eine signifikante Erhöhung der Wassertemperaturen in den belasteten Gewässerabschnitten. Durch den Gold-Tagebau wurden weiterhin die Auenvegetation und die natürlichen Uferstrukturen zerstört, was zu vielfältigen Habitatveränderungen führt. 3. Die untersuchten Effekte des Gold-Tagebaus sind als sublethal und verhaltens-verändernd einzustufen. Sie wirken sich z.B. auf das funktionale Gefüge der verschiedenen trophischen Ebenen des Fließgewässerökosystems aus. So wiesen zahlreiche Fischarten einen signifikant verringerten Konditionsfaktor auf, der offensichtlich bottom-up gesteuert durch verminderten Aufwuchs und geringere Abundanzen des Makrozoobenthos verursacht wird. Auch wurde ein deutlicher Einfluss auf die Fischwanderung festgestellt, der vermutlich durch ungünstige physikalisch-chemische oder hydraulische Habitateigenschaften innerhalb des Abbaugebiets verursacht wird. Für Arktische Äschen und Lenok ist das Abbaugebiet nicht oder nur eingeschränkt passierbar. 4. Die Kolmation des Kieslückensystems führte zum Verlust von Laich- und Überwinterungshabitaten und ist daher als ein gravierender Einflussfaktor für die lokale Fischfauna einzustufen. 5. Letale Effekte wie Kiemen- oder Schleimhautverletzungen auf Grund von direkter Schädigung der Tiere durch die erhöhten Schwebstofffrachten wurden nicht beobachtet. Im Rahmen der Arbeit wurden ökologische Grundlagenkenntnisse zu Fischbeständen und Populationsdynamiken im Nord-Osten der Mongolei erarbeitet. Diese Informationen tragen zu einem besseren Verständnis der Gefährdungsursachen bei. Auf Basis der gewonnenen Erkenntnisse über die Ökologie der Arten und der Einflüsse des Gold-Tagebaus wurden Managementempfehlungen unterschiedlicher Priorität formuliert und an Hand eines Fallbeispiels exemplarisch bearbeitet. Darüber hinaus wurden Grundlagen für ein ökologisches Monitoring des Gold-Tagebaus entwickelt. / The fish fauna of Mongolia comprises 64 species of which eleven are regionally endangered and four potentially endangered according to the Red List of Mongolian Fish. Gold mining is regarded as one of the major causes for declining fish populations. Many gold deposits are found in the alluvial sediments of the floodplains and are extracted by large scale mining and mechanical elutriation. This heavily disturbs the balance of suspended sediments and matter in running waters and affects the habitat availability and quality for the fish fauna. Thus, the primary objective of this study was the abiotic and ichthyological characterization of selected reference waters and waters influenced by gold mining as well as the quantification of gold mining effects. Furthermore, an aim was the formulation of management strategies for a sustainable development of the expanding mining sector in Mongolia. The investigation took place from 2003 to 2006 at four rhitral waters of the Khentii Mountains in north-east Mongolia. Data acquisition of the fish fauna was carried out with electric fishing devices and fish traps on representative habitats. In addition, the balance of mater and characteristics of the hyporheic zone were analyzed, relevant habitats mapped and the migratory behavior of selected species experimentally studied. The following major results were obtained from this research: 1. The fish fauna of the examined waters comprised 14 taxa dominated by rhitral characteristic species like salmonids, arctic grayling and minnows. The fish population was strongly seasonally influenced, whereas small running waters being repopulated yearly in spring. 2. Gold mining brings about an increase in concentrations of suspended sediment and clogging of the hyporheic interstitial. Physical-chemical investigations primarily identified a significant rise in water temperatures in the polluted water sectors. Furthermore, gold mining degrades floodplain vegetation and natural bank structures causing varied habitat changes. 3. The examined gold mining effects are sublethal to fish or influence their behavior. They disrupt the functional arrangement of the different trophic levels of the river ecosystem. Thus, the condition of some fish species was significantly decreased, evidently regulated bottom-up by depleted periphyton and reduced abundances of macro invertebrates. Moreover, a strong influence on the river continuum was assessed. Arctic grayling and lenok did not migrate through the mining area, possibly due to unfavorable physical-chemical or hydraulic conditions within the mining site. 4. The clogging of the river bed substrate resulted in a loss of spawning and hibernation habitats and thus must be regarded as a major thread to the local fish fauna. 5. Lethal effects like injuries of gills or skin by direct lesions of suspended particles could not be observed. In this study basic ecological knowledge and population dynamics of the fish fauna in north-east Mongolia have been identified. This information is fundamental for a better understanding of the causes of endangerment. Based on the findings on the ecology of fish species and the influences of gold-mining management recommendations of different priority were developed and exemplified in a case study. Furthermore, this study worked out basic principles for an ecological monitoring of gold mining.

Background: ST-elevation acute myocardial infarction (STEMI) represents one of the leading causes of death. The time of STEMI onset has a circadian rhythm with a peak during diurnal hours, and the occurrence of STEMI follows a seasonal pattern with a salient peak of cases in the winter months and a marked reduction of cases in the summer months. Scholars investigated the reason behind the winter peak, suggesting that environmental and climatic factors concur in STEMI pathogenesis, but no studies have investigated whether the circadian rhythm is modified with the seasonal pattern, in particular during the summer reduction in STEMI occurrence. Methods and Results: Here, we provide a multiethnic and multination epidemiological study (from both hemispheres at different latitudes, n=2270 cases) that investigates whether the circadian variation of STEMI onset is altered in the summer season. The main finding is that the difference between numbers of diurnal (6:00 to 18:00) and nocturnal (18:00 to 6:00) STEMI is markedly decreased in the summer season, and this is a prodrome of a complex mechanism according to which the circadian rhythm of STEMI time onset seems season dependent. Conclusions: The “summer shift” of STEMI to the nocturnal interval is consistent across different populations, and the sunshine duration (a measure related to cloudiness and solar irradiance) underpins this season-dependent circadian perturbation. Vitamin D, which in our results seems correlated with this summer shift, is also primarily regulated by the sunshine duration, and future studies should investigate their joint role in the mechanisms of STEMI etiogenesis.

Time series data are of great importance for monitoring vegetation phenology in the dry sub-humid regions where change in land cover has influence on biomass productivity. However few studies have inquired into examining the impact of rainfall and land cover change on vegetation phenology. This study explores Seasonal Trend Analysis (STA) approach in order to investigate overall greenness, peak of annual greenness and timing of annual greenness in the seasonal NDVI cycle. Phenological pattern for the start of season (SOS) and end of season (EOS) was also examined across different land cover types in four selected locations. A significant increase in overall greenness (amplitude 0) and a significant decrease in other greenness trend maps (amplitude 1 and phase 1) was observed over the study period. Moreover significant positive trends in overall annual rainfall (amplitude 0) was found which follows similar pattern with vegetation trend. Variation in the timing of peak of greenness (phase 1) was seen in the four selected locations, this indicate a change in phenological trend. Additionally, strong relationship was revealed by the result of the pixel-wise regression between NDVI and rainfall. Change in vegetation phenology in the study area is attributed to climatic variability than anthropogenic activities.

Prairie dogs (Cynomys sp.) are considered keystone species and ecosystem engineers for their grazing and burrowing activities (summarized here as disturbances). As climate changes and its variability increases, the mechanisms underlying organisms' interactions with their habitat will likely shift. Understanding the mediating role of prairie dog disturbance on vegetation structure, and its interaction with environmental conditions through time, will increase knowledge on the risks and vulnerability of grasslands. Here, we compared how plant taxonomical diversity, functional diversity metrics, and community-weighted trait means (CWM) respond to prairie dog C. mexicanus disturbance across grassland types and seasons (dry and wet) in a priority conservation semiarid grassland of Northeast Mexico. Our findings suggest that functional metrics and CWM analyses responded to interactions between prairie dog disturbance, grassland type and season, whilst species diversity and cover measures were less sensitive to the role of prairie dog disturbance. We found weak evidence that prairie dog disturbance has a negative effect on vegetation structure, except for minimal effects on C4 and graminoid cover, but which depended mainly on season. Grassland type and season explained most of the effects on plant functional and taxonomic diversity as well as CWM traits. Furthermore, we found that leaf area as well as forb and annual cover increased during the wet season, independent of prairie dog disturbance. Our results provide evidence that grassland type and season have a stronger effect than prairie dog disturbance on the vegetation of this short-grass, water-restricted grassland ecosystem. We argue that focusing solely on disturbance and grazing effects is misleading, and attention is needed on the relationships between vegetation and environmental conditions which will be critical to understand semiarid grassland dynamics under future climate change conditions in the region.

Die vorliegende Dissertation widmet sich methodischen und empirischen Forschungsfragen mit Bezug auf saisonale Arbeitsmärkte und Politiken zur nachhaltigen Nutzung natürlicher Ressourcen. Hierfür wird ein gesamtwirtschaftlicher Modellierungsansatz angewendet, für den das im südöstlichen Himalaya gelegene Königreich Bhutan als empirische Fallstudie dient. Das methodische Forschungsziel der Arbeit ist, die Relevanz der Darstellung von saisonalen Arbeitsmärkten innerhalb von allgemeinen Gleichgewichtsmodellen (sog. CGE Modelle) zu ergründen. Dies stellt eine Neuheit in der Literatur dar. Die Arbeit zeigt auf, dass Modelle ohne saisonale Arbeitsmärkte systematisch Ergebnisse, wie Angebotsreaktionen und Wohlstandseffekte, verzerren. Die Saisonalität von Arbeit hat eine hohe Relevanz für gesamtwirtschaftliche Analysen im Kontext landwirtschaftlich geprägter Volkswirtschaften, insbesondere für Untersuchungen des Strukturwandels und agrarpolitischer Interventionen. Empirisch wird die wechselseitige Abhängigkeit von Politiken zum nachhaltigen Management natürlicher Ressourcen mit Zielen des Umweltschutzes und der ländlichen Entwicklung untersucht. Basierend auf unterschiedlichen Modellierungsansätzen, konzentrieren sich drei Studien auf agrar- und forstpolitische Szenarien in Bhutan. Es wird gezeigt, dass Bhutans Ziel, seinen landwirtschaftlichen Sektor auf 100% ökologische Landwirtschaft umzustellen, zu substantiellen Wohlfahrtsverlusten und negativen Folgen für die Ernährungssicherung führen würde. Die Analyse verschiedener forstpolitischer Szenarien demonstriert, dass eine höhere Forstnutzung in Bhutan im Sinne der gesamtwirtschaftlichen und ländlichen Entwicklung nachhaltig möglich ist. Die Arbeit weist auf verschiedene zukünftige Forschungsfelder hin, wie zum Beispiel die Integration von Ökosystemdienstleistungen, was als eine der wesentlichen Einschränkungen bei der modellgestützten Analyse von Politiken zur Nutzung natürlicher Ressourcen identifiziert wurde. / Using an economy-wide modelling approach, this dissertation investigates methodological and empirical research questions related to seasonal labour markets and natural resource policies. The Kingdom of Bhutan, located in the south-eastern Himalayas, serves as a case study. The methodological research objective of this thesis is to gain an understanding of the relevance of seasonal labour markets in the context of economy-wide modelling. The depiction of seasonal labour markets at national scale using a seasonal social accounting matrix (SAM) and computable general equilibrium (CGE) model presents a novel development within the literature. It is demonstrated, that the absence of seasonal labour markets leads to systematic bias of model results. The consequences are distorted supply responses and biased welfare effects, underlining the pivotal implications of seasonality for economy-wide analysis in the context of agrarian economies, particularly for scenario analysis involving structural changes and agricultural policy interventions. The empirical research objective addresses the interdependence of natural resource policies with objectives of environmental conservation and rural development. Employing modelling techniques, three studies focus on specific agricultural and forest policy scenarios in Bhutan. Simulating Bhutan’s ambitious policy objective to convert to 100% organic agriculture demonstrates substantial welfare losses and adverse impacts on food security, causing trade-offs with objectives of rural development and food self-sufficiency. Analysing forest policy reforms shows that increased forest utilization contributes to economic development, particularly in rural areas, without jeopardizing the country’s forest conservation agenda. The dissertation points at numerous areas of future research, as for example the incorporation of ecosystem services, which is identified as one key limitation of economy-wide analysis of natural resource policies.

No description available.