A Tale of Two Morphs: Genetic and Genotypic Structure Between Macrocystis Pyrifera and Macrocystis Integrifolia

Organisms living along environmental gradients often utilize phenotypic plasticity to maximize their survival across a range of conditions. Wherever gradients occur, there is potential for divergence through isolation-by-adaptation (IBA) to build-up between genotypes experiencing different selective pressures. Plasticity in traits pertaining to mating systems in particular are likely to constitute an interesting and revealing model for the study of the underlying mechanisms behind parapatric speciation. Giant kelp, Macrocystis spp., shows striking plasticity in holdfast morphology and reproductive strategy when colonizing intertidal (M. integrifolia morph) versus subtidal (M. pyrifera morph) areas along temperate rocky coastlines of the eastern Pacific Ocean. In the intertidal, high photosynthetically-active radiation (PAR) and UV radiation limit development of spores, recruitment of microscopic gametophytes, and growth and survival of embryonic sporophytes of M. pyrifera. Although depth of parent sporophytes influences spore survival in irradiance-stressed environments, few studies have examined the effects of irradiance stress on M. integrifolia’s developmental stages. This study focuses on understanding the roles of IBA and plasticity in maintaining Macrocystis morphs along the California coastline. To test for genetic isolation caused by ecological divergence in the intertidal, we performed fine scale spatial sampling and molecular analysis of parapatric intertidal and subtidal populations off of the Central Californian coast. Using seven microsatellite markers, we compared genetic differentiation between morphs within sites and among morphs across different sites. Furthermore, we identified the presence of clonal replicates in intertidal populations. Results show higher differentiation between adjacent subtidal and intertidal morphs than between the same morph at larger spatial scales, suggesting isolation-by-adaptation. Several potential mechanisms could explain this result: assortative or other non-random mating, longer generation times promoted by asexual growth (intertidal morph), and differential mortality due to early adaptive divergence. Spatial analyses of clonal structure do not indicate asexual reproduction as the dominant strategy in the intertidal. To explore the hypothesis of differential mortality due to adaptive divergence, we will experimentally test assortative mating at different early development stages using controlled crosses of the two morphs under different treatments of irradiance (PAR and UV) stress. Surviving embryonic sporophytes will be genotyped and a paternity analysis will be conducted. Specifically, we hypothesize offspring from M. pyrifera parents will experience higher than expected mortality under irradiance stress, such that paternity analyses will reveal lower than expected numbers of M. pyrifera offspring among surviving embryonic sporophytes. The overarching goal of this research program is to determine if phenotypic plasticity in mating system traits observed in giant kelp may be facilitating incipient parapatric speciation in the intertidal zone. This thesis will consist of three chapters. The first will concentrate on understanding the impact of alternative methods M. pyrifera utilizes for dispersal at both ecological and evolutionary scales. The second will focus on characterizing genetic differentiation and structure patterns between adjacent populations of each morph. The third will develop additional hypotheses focused on understanding differential mortality between morphs under stress

Paradigmenwechsel in der deutschen Afrikapolitik?

Die vorliegende Diplomarbeit „Paradigmenwechsel in der deutschen Afrikapolitik? Anspruch und Realität der gegenwärtigen afrikapolitischen Neuausrichtung am Beispiel Nigerias“ untersucht in einem ersten Schritt mögliche Wendepunkte und Veränderungen, aber auch Kontinuitäten bisheriger Phasen der deutschen Afrikapolitik seit ihrem Wiederbeginn nach 1945. Die hierbei erarbeiteten Merkmale und Handlungsmuster sollen daraufhin den Rahmen für eine Analyse der gegenwärtigen Afrikapolitik bilden. Hierbei wird insbesondere der Frage nachgegangen, inwiefern es seit der im Jahr 2000 vielfach prognostizierten Neuausrichtung deutscher Afrikapolitik auch tatsächlich auch zu einem nachhaltigen Paradigmenwandel in politischer Handlungsebene und Entscheidungsfindung gekommen ist und wie dieser möglicherweise in die bisherigen afrikapolitischen Perioden der Vergangenheit eingeordnet werden kann. Um dem Umfang des afrikapolitischen Handlungsfeldes gerecht zu werden, soll dabei nicht nur die Bundesregierung als ausführende Instanz untersucht werden, sondern auch nicht- und halbstaatliche Akteure wie etwa politische Stiftungen, NROs oder die Epistemic Community, sowie die europäische Afrikastrategie berücksichtigt werden. In einer abschließenden Gesamtüberprüfung werden die Ergebnisse anhand einer Fallanalyse zu Nigeria überprüft. Hierbei stehen neben dem -für Nigeria relevanten- afrikanischen Kontext (NEPAD und ECOWAS) vor allem außenpolitische Identität und Rollenverständnis Nigerias innerhalb der westafrikanischen Region im Vordergrund. Da es in der Forschungsarbeit nicht um die vordergründige und offensichtliche Ebene des politischen Handelns geht, sondern der Schwerpunkt vielmehr auf verborgenen Strukturen und Wirkungsmechanismen liegt, wird der theoretische Rahmen mithilfe der konstruktivistischen Forschungsperspektive abgedeckt. Hierbei wird anhand von einzelnen Kriterien, wie etwa Definitionsmacht, Identität, Idee oder auch Rollenerwartung ein konstruktivistischer Analyserahmen definiert, der es ermöglicht, bestehende Machtbeziehungen zu entschlüsseln, gängige Weltbilder zu dekonstruieren und somit die soziale Konstruktion von politischen Beziehungen und ihren Akteuren zu verstehen und zu bewerten. Bereits im ersten Analyseschritt wurde deutlich, dass die deutsche Afrikapolitik- analog zur gesamten Außenpolitik- überwiegend durch Kontinuität bestimmt ist. Darüber hinaus skizziert sich die deutsche Politik gegenüber Afrika vor allem in den 1960er-70er Jahren vor dem Hintergrund eigener nationalpolitischer Veränderungen, wie etwa dem Ost-West-Antagonismus, in dessen Folge Afrika zum Austragungsort einer Konkurrenz zwischen Kommunismus und Sozialismus fungiert. Weitere Aspekte, die einen afrikapolitischen Wandel notwendig erschienen ließen waren etwa eine kontinuierliche europäische Integration, die schließlich eine grundlegende Übereinstimmung mit europäischen Zielformulierungen und Strukturen erforderte, sowie ein wirtschaftspolitisches Interesse an Afrika. Modifikationen in der deutschen Afrikapolitik finden überwiegend vor dem eigenen nationalpolitischen oder europäischen Rahmen statt, nicht aber in realpolitischer Beziehungen zu Afrika selbst. Ein reaktiver Wirkungsmechanismus, der sich afrikanischen Wandlungen und Veränderungen anpasst, konnte nur selten erkannt werden. Die Überprüfung der Ergebnisse am Fallbeispiel zu Nigeria bekräftigt diesen Ansatz. Im Rahmen des Ankerland- Konzeptes, das den zentralen Rahmen deutsch-nigerianischer Kooperationen bestimmen soll wurde deutlich, dass weder Nigeria tatsächlich einem Ankerland entspricht, noch die Anforderungen, die von Deutschland angesichts dieses Konzepts erwarten werden müssten, erfüllt werden. Die deutsche Afrikapolitik gegenüber Nigeria wird also weder dem eigenen Anspruch gerecht, noch spiegelt sie die innen- wie außenpolitische Realität angemessen Nigerias. Letztendlich bestätigt auch diese Einsicht, dass konträr zu der prognostizierten afrikapolitischen Neuausrichtung bisher keine umfassenden Erneuerungen oder Wandlungen stattgefunden haben, die es erlauben würden, von einem Paradigmenwechsel in der deutschen Afrikapolitik zu sprechen.The diploma thesis „Paradigmenwechsel in der deutschen Afrikapolitik? Anspruch und Wirklichkeit der gegenwärtigen afrikapolitischen Neuausrichtung am Beispiel Nigerias“ („Paradigm change in Germany’s Africa policy? Pretense and reality of the present reorientation on the example of Nigeria“) firstly analysis potential shifts and changes, as well as continuities in German policy towards Africa since its restart after 1945. Characteristics and patterns of action that can be elaborated from this analysis build the scope of a further concentration on present policy towards Africa. In this respect, the thesis investigates a potential paradigm change since its predicted reorientation in 2000. Besides a focus on the federal government as the main performer, semi-governmental and private actors, such as political foundations, NGOs, the epistemic community, as well as the European Strategy towards Africa, will be considered. A final chapter reassesses major findings on the basis of a case analysis on Nigeria. As the analysis does not concentrate on the obvious and visible level of political actions, but rather on subliminal actions and mechanisms, the research perspective of constructivism appeared reasonable. In this context, a constructivist analytical framework was developed, which includes criteria such as the power of naming/normative power, identity, ideas and role expectations. Thus, the constructivist perspective not only allows to deconstruct existing relations of power or world views, but also to understand and evaluate the social construction of political relations and their actors. In the first analysis, it became apparent that German Africa policy -along the lines of foreign policy- is predominantly shaped by continuity. Besides a general low profile, policy towards Africa was mainly influenced by economic and power-political interests. Particularly in the 1960s and 1970s, German policy was affected by the East-West-antagonism, in which Africa appeared to be a venue of rivalry between West-Germany and the GDR. Further aspects that have influenced the current German policy towards Africa were the continuing European integration, which demanded an increased consensus in goal setting and implementation of a collective European strategy towards Africa, as well as continuing economic-political interests. Especially with economically strong states such as South Africa or Nigeria, Germany kept continuing foreign trade even under disputable conditions: Despite severe criticism and an international imposition of sanctions against the South African apartheid regime, Germany remained largely unaffected. In terms of German policy towards Nigeria, an analysis of pretense and reality on the basis of the so called Anchor country- concept (Ankerland- Konzept) reconfirmed most previous assumptions. Apart from the fact that Nigeria –by virtue of domestically and external challenges- does not meet the expectations resulting from the anchor country- concept, Germany is largely unable to co-operate with Nigeria according to its own demands. Thus, neither on the Nigerian, nor on the German side do abilities meet the requirements. Consequently, the prognosticated paradigm of Germany’s Africa policy, which would include a strategy based on country-specific measures, could not be identified

A Cross-Sectional Analysis of Health Impacts of Inorganic Arsenic in Chemical Mixtures

Drinking groundwater is the primary way humans accumulate arsenic. Chronic exposure to inorganic arsenic (iAs) (over decades) has been shown to be associated with multiple health effects at low levels (5-10 ppb) including: cancer, elevated blood pressure and cardiovascular disease, skin lesions, renal failure, and peripheral neuropathy. Using hypertension (or high blood pressure) as a surrogate marker for cardiovascular disease, we examined the effect of iAs alone and in a mixture with other metals using a cross-sectional study of adults in United States (National Health and Examination Survey, NHANES, 2005-2010) adjusting for covariates: urinary creatinine level (mg/dL), poverty index ratio (PIR, measure of socioeconomic status, 1 to 5), age, smoking (yes/no), alcohol usage, gender, non-Hispanic Black, and overweight (BMI\u3e=25). A logistic regression model suggests that a one-unit increase in log of inorganic arsenic increases the odds of hypertension by a factor of 1.093 (95% Confidence Interval=0.935, 1.277) adjusted for these covariates , which indicates that there was not significant evidence to claim that inorganic arsenic is a risk factor for hypertension. Biomonitoring data provides evidence that humans are not only exposed to inorganic arsenic but also to mixtures of chemicals including inorganic arsenic, total mercury, cadmium, and lead. We tested for a mixture effect of these four environmental chemicals using weighted quantile sum (WQS) regression, which takes into account the correlation among the chemicals and with the outcome. For one-unit increase in the weighted sum, the adjusted odds of developing hypertension increases by a factor of 1.027 (95% CI=0.882,1.196), which is also not significant after taking into account the same covariates. The insignificant finding may be due to the low inorganic arsenic concentration (8-620 μg /L) in US drinking water, compared to those in countries like Bangladesh where the concentrations are much higher. Literature provides conflicting evidence of the association of inorganic arsenic and hypertension in low/moderate regions; future studies, especially a large cohort study, are needed to confirm if inorganic arsenic alone or with other metals is associated with hypertension in the United States

Thoughts on Quorum Sensing and Fungal Dimorphism

Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications that the use of farnesol as both a signaling molecule and to antagonize competing microbials species has for the regulation of HMG-CoA reductase, the enzyme that is the usual rate limiting step in sterol/lipid synthesis

Thoughts on Quorum Sensing and Fungal Dimorphism

Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications that the use of farnesol as both a signaling molecule and to antagonize competing microbials species has for the regulation of HMG-CoA reductase, the enzyme that is the usual rate limiting step in sterol/lipid synthesis

Objectives and Achievements of the Hypersonic Flight Experiment STORT

The three-stage rocket configuration of the hypersonic experiment STORT with several scientific payloads concerning hypersonic technologies was launched from the Andøya Space launch site in northern Norway on 26th June 2026 successfully. The third stage performed a suppressed trajectory to increase integral heat load on the structures of payloads. The duration of a flight phase above Mach 8 at altitudes between 30 km and 38 km was more than 60 seconds. The nose and forebody section of the payload is made of the CMC structures. Three canards with a CMC thermal protection were equipped with thermal management experiments to verify the thermal efficiency of these methods. All engineering science experiments like aerothermal heating of the nose and forebody, CMC material response at temperatures above 2200 K, hypersonic thermal management, shock wave boundary layer interaction, CFRP module with cork coating for high temperature applications, high temperature fin leading edge and radiometer sensors provided unique flight data. A reduced in-flight 3 DoF trajectory simulation running on the flight computer determined the ignition time of the third stage which allowed improved experiment conditions in terms of Mach number and apogee altitude even in the presence of external perturbations

Linking emergency care and police department data to strengthen timely information on violence-related paediatric injuries

Background Combined ED and police department (PD) data have improved violence surveillance in the UK, enabling significantly improved prevention. We sought to determine if the addition of emergency medical service (EMS) data to ED data would contribute meaningful information on violence-related paediatric injuries beyond PD record data in a US city. Methods Cross-sectional data on self-reported violence-related injuries of youth treated in the ED between January 2015 and September 2016 were combined with incidents classified by EMS as intentional interpersonal violence and incidents in which the PD responded to a youth injury from a simple or aggravated assault, robbery or sexual offence. Nearest neighbour hierarchical spatial clustering detected areas in which 10 or more incidents occurred during this period (hotspots), with the radii of the area being 1000, 1500, 2000 and 3000 ft. Overlap of PD incidents within ED&EMS hotspots (and vice versa) was calculated and Spearman’s r tested statistical associations between the data sets, or ED&EMS contribution to PD violence information. Results There were 935 unique ED&EMS records (ED=381; EMS=554). Of these, 877 (94%) were not in PD records. In large hotspots >2000 ft, ED&EMS records identified one additional incident for every three in the PD database. ED and EMS provided significant numbers of incidents not reported to PD. Significant correlations of ED&EMS incidents in PD hotspots imply that the ED&EMS incidents are as pervasive across the city as that reported by PD. In addition, ED and EMS provided unique violence information, as ED&EMS hotspots never included a majority (>50%) of PD records. Most (676/877; 77%) incidents unique to ED&EMS records were within 1000 ft of a school or park. Conclusions Many violence locations in ED and EMS data were not present in PD records. A combined PD, ED and EMS database resulted in new knowledge of the geospatial distribution of violence-related paediatric injuries and can be used for data-informed and targeted prevention of violence in which children are injured—especially in and around schools and parks

Selected results of the hypersonic flight experiment STORT

The three-stage rocket configuration of the hypersonic experiment STORT with several scientific payloads concerning hypersonic technologies was launched successfully from the Andøya Space launch site in northern Norway on 26th June 2022. The third stage performed a suppressed trajectory to increase integral heat load on the payload structures. The vehicle traveled at speeds above Mach 8 at altitudes between 30 km and 38 km for more than 60 seconds. The nose and forebody section of the payload was made of CMC structures. Three canards with a CMC thermal protection were equipped with thermal management experiments to verify the thermal efficiency of these methods. All engineering science experiments like aerothermal heating of the nose and forebody, CMC material response at temperatures above 2200 K, hypersonic thermal management, shock wave boundary layer interaction, CFRP module with cork coating for high temperature applications, high temperature fin leading edge and radiometer sensors provided unique flight data. A reduced in-flight 3 DoF trajectory simulation running on the flight computer determined the ignition time of the third stage which allowed improved experiment conditions in terms of Mach number and apogee altitude even in the presence of external perturbation

Design, Manufacturing and Assembly of the STORT Hypersonic Flight Experiment Thermal Protection System

STORT is a DLR project focused on testing of key technologies for flight at hypersonic Mach numbers of higher than 8 for a relatively long time. The overarching aim of the project is to support cost reduction of future space transportation systems while at the same time keeping them highly reliable. To this end, reusability of all stages of future launcher systems is a prerequisite. For first stages, a Mach number of 8-10 seems to be the optimum staging velocity, which means that technologies for the return flight of first stages at those speeds need to be developed and validated. Consequently, STORT aimed at achieving operating conditions representative of such high-energetic reentry flights for reusable first stages at Mach 8, to support the optimization and validation of technologies and simulation tools for the development of future space transportation systems. The present paper thus describes the design, manufacturing and integration of the rocket forebody assembly up to the launch of the vehicle. In addition, an overview of the collected flight data from the thermal protection system sensors is given. The forebody thermal protection system requires the use of ceramic matrix composite material for protection from the high heat loads experienced during the flight. In the present case the thermal protection system was constituted by C/C-SiC composite structures built in-house by DLR. The main elements were a conical nose element and four thin-walled shell segments manufactured via filament winding of carbon fibers. Via an in-situ joining process, integral fixation brackets from CMC material were permanently attached to the shells. The underlying forebody main structure to which the thermal protection system structures were connected was made from aluminum