L’origine des éléments volatils, éléments avec des températures de condensation très basses comme l’eau, l’azote, le carbone et les gaz rares, sur Terre et sur les autres planètes telluriques reste mal comprise. Comprendre comment ces éléments sont arrivés sur Terre permettra de mieux appréhender les mécanismes de formation du système solaire. De par leur caractère inerte, les gaz rares (He, Ne, Ar, Kr, Xe) constituent des traceurs uniques des sources d’éléments volatils. L’étude de la composition en gaz rares du manteau terrestre s’avère donc essentielle afin de déterminer l’origine de ces éléments. L’objectif de ces travaux était de mesurer précisément la composition des isotopes stables et non-radiogéniques des gaz rares dans le manteau à partir de verres basaltiques. Ces derniers étant très souvent contaminés par l’air, des techniques d’analyse des gaz rares ont été mises en place pour s’affranchir de cette contamination. Des échantillons du volcan Fernandina du point chaud des Galápagos ont été étudiés par ablation laser. Les résultats montrent que le rapport 20Ne/22Ne des bulles est en moyenne de 12,65 ± 0,04 (1σ), ce qui est proche de la valeur estimée pour le pôle d’implantation du vent solaire (~ 12,7). Cette étude suggère donc que l’implantation du vent solaire sur les grains précurseurs de la Terre serait à l’origine des éléments volatils légers du manteau.Des données d’échantillons de popping rocks, aussi analysés par cette technique, indiquent que le manteau supérieur est hétérogène à petite échelle et pourraient impliquer le recyclage de gaz rares dans le manteau, y compris He, Ne, lors de la subduction. Un nouveau protocole d’analyse du Kr et Xe a été développé. Les résultats montrent les plus forts excès en 124Xe, 126Xe et 128Xe mesurés pour le manteau et suggèrent une source chondritique. Les isotopes fissiogéniques du xénon ont permis de dater le début du recyclage des éléments volatils dans le manteau aux alentours de 3 Ga. / The origin of volatiles, elements with low condensation temperatures such as water, nitrogen, carbon and noble gases, on Earth and other terrestrial planets is still misunderstood. Determining how these elements were delivered to the Earth will allow a better understanding of the processes of solar system formation. Due to their inertness, noble gases (He, Ne, Ar, Kr, Xe) constitute unique tracers of volatiles sources. Studying the noble gas composition of the Earth’s mantle is hence critical to unravel volatile origin. The aim of this PhD was to measure precisely the composition of non-radiogenic, stable noble gas isotopes in the mantle from basaltic glasses. The latter being very often contaminated by air, analytical techniques were thus set up to overcome this contamination.Samples from Fernandina volcano from the Galápagos hotspot were studied with laser ablation. The results show that the mean 20Ne/22Ne ratio in the vesicles is 12.65 ± 0.04 (1σ), close to the estimated value of the solar wind implanted end-member (~ 12,7). This study suggests that light volatiles in the mantle would originate from implantation of solar wind on the Earth’s precursors grains. Data from popping rock samples, also analyzed with this technique, indicate that the upper mantle is heterogeneous at small scale and that noble gases, included He, Ne, could be recycled into the mantle in subduction zones. A new protocol to analyse Kr and Xe was set up. The results show the highest measured excess in 124Xe, 126Xe and 128Xe for the mantle and suggest a chondritic source. The xenon fissiogenic isotopes allowed us to constrain the onset of volatile recycling in the mantle to around 3 Ga.

This study investigates whether in-uterus earthquake exposure causes long-term labor, human capital, and health effects. The health shock is maternal stress, which generates excessive concentration levels of cortisol in the fetal environment, negatively impacting the development of the fetus. I use multiple earthquakes between the years 1960-1980 in the setting of Colombia. In my definition of earthquake exposure, I consider both the intensity and the extent of the shaking. Difference-in-difference estimates show mixed results. I find a higher likelihood of being disabled when exposed during the first trimester and the favorable effect of more years of schooling when exposed during the final trimester. Separating the analysis by gender indicates that the effect on disability is centered around males, while results indicating favorable effects are found among females. Generally, exposure from high intensity shaking generates larger point estimates. The results are sensitive to the exclusion of specific earthquakes. In addition, when including those exposed to shaking that were either not felt or weak into the treatment group, some estimates indicate a long-term impact from such exposure. Based on these inconsistencies I am not able to make any general or causal claims.

What is the probability that in a fair coin toss game (a simple random walk) we go bankrupt in n steps when there is an initial lead of some known or unknown quantity $m? What is the distribution of the number of steps N that it takes for the lead to vanish? This thesis explores some of the features of this first passage to the origin (FPO) distribution. First, we explore the distribution of N when m is known. Next, we compute the maximum likelihood estimators of m for a fixed n and also the posterior distribution of m when we are given that m follows some known prior distribution.

DNA replication is a highly complex part of cell metabolism that ensures safe propagation of the genome through tight regulation of the expression, localization, and activity of a large number of factors. Replication starts from distinct sites in the genome and initiation events are temporally ordered in a manner that is, on average, highly reproducible across cell populations. The specific order with which different parts of the genome are replicated has been proposed to be important to processes such as gene expression, cell differentiation, development, and genome evolution. Nevertheless, the fundamental mechanisms that are responsible for establishing these timing programs remain elusive. Unlike in higher eukaryotes, DNA replication in budding yeast initiates at sequence-specific loci called origins of replication. The timing of initiation at these loci is determined by the activation of the main replicative helicase Minichromosome Maintenance (MCM) complex. Recent results have placed MCM in a key role in establishing a replication timing program that is reproducible but arises from stochastic activation of origins, as has been observed in yeast and higher eukaryotes. One particular model posits that the loading of multiple MCMs at individual origins increases the chances that origins will be activated earlier in S phase by a limited amount of initiation factors. To further test this model, we set out to examine the consequences of modulating MCM levels in budding yeast in order to ascertain their effects on the dynamics of helicase loading during G1 and subsequent replication timing. Overexpression of MCM2-7 had no effects on cell viability, cell cycle progression, MCM abundance at origins, or replication timing. On the other hand, depletion of Mcm4, one of the six obligate components of the MCM helicase, caused reduced viability, slower progression through S phase, and increased sensitivity to replication stress. Importantly, Mcm4 depletion led to differential reduction in MCM loading at origins during G1, with low MCM origins being disproportionately affected by reduced MCM pools. Finally, reduced MCM loading at origins of replication led to delayed replication during S phase. Our data support a model where the loading activity of origins, controlled by their ability to recruit ORC and compete for MCMs, determines the number of helicases loaded, which in turn has strong implications for replication timing.

The Arumbera Sandstone consists of mappable informal units which are repeated in a vertical, cyclic succession. Sandstones of fluvial origin form resistant strike ridges separated by strike valleys, which consist of recessive sandstones and mudrocks of marine origin. Lithofacies 1a, 2b, and 3a are probably of marine origin in intertidal environments. Trace fossil assemblages in lithofacies 3a suggest Skolithos and Cruziana inchnofacies were present. Lithofacies 1e, 2a, 2c, 3b, and 4a are probably of fluvial origin, as the result of coalescing braided stream deposits. The Arumbera Sandstone probably was deposited in a deltaic environment characterized by low wave energy, a micro tidal range, and high input of sand-sized sediment br braided streams. In the western MacDonnell Ranges, the Arumbera overlies the Julie or Pertatataka formations along a sharp but conformable contact. The present upper contact is a low-angle regional unconformity which contains paleotopographic elements that resemble pediments, stripped structural plains, and steep erosional scarps. These paleotopographic surfaces are overlain from east to west by the Chandler, hugh River, and Cleland formations in an onlap relationship. The Arumbera Sandstone is considered part of a molasse sequence associated with the Late Proterozoic and Early Cambrian Petermann Ranges orogeny, which occurred along the present southern and southwestern margin of the Amadeus Basin. The uplifted Petermann Ranges shed detritus from metamorphic, sedimentary, and minor amounts of plutonic rocks. Paleocurrents suggest most terrigenous material was derived from the southwestern margin of the basin. The composition of detrital grains and lack of weathering features in labile detrital grains suggest a hot, semiarid to arid climate in the source area and in the basin of deposition. Sandstone samples examined petrographically primarily are subphyllarenites, subarkoses, arkoses, feldspathic litharenites, and lithic arkoses. The inferred paragenetic sequence is: Eogenetic: (1) mechanical compaction, (2) "dust rims" of hematite, illite, and chlorite, and (3) hematite cement; Mesogenetic: (4) syntaxial feldspar overgrowths, (5) syntaxial quartz overgrowths, (6) hematite cement, (7) carbonate cement, (8) kaolinite replacement, (9) formation of secondary porosity; Telogenetic: (10) chert cement and (11) gibbsite or hematite cement.

No description available.

Some unanswered questions about consciousness as a biological phenomenon lie in its evolutionary origin and distribution among living organisms. Which animals are conscious and when did consciousness appear in the history of life on earth? The purpose of this thesis is to shed light on these long-standing questions by reviewing the literature on the evolutionary approaches to the fundamental concept of phenomenal consciousness. In agreement with the “Cambridge Declaration on Consciousness,” this study aims to introduce three recently developed theories, with a particular emphasis on examining one model. The “Cellular Basis of Consciousness” (CBC) is a reductionist, cellular-based model that argues all organisms from unicellular to humans are sentient. Another theory based on neuroevolutionary arguments is called the “Neurobiological Naturalism.” It suggests that consciousness first appeared duringthe Cambrian period about 550 million years ago. This model considers vertebrates, arthropods and cephalopods as conscious animals. An alternative framework, which is the main focus of this thesis, is the “Unlimited Associative Learning” (UAL). The UAL model employs a novel method to formulate a transition marker as an indicator of consciousness. Although the UAL framework is a promising method for tracing the evolution of consciousness, it also has significant limitations. Nevertheless, the literature review reveals that as an innovative framework, UAL has the potential to generate fruitful research programs. Rather than providing a final answer, it can be considered a significant starting point for unraveling the origin of consciousness.

No description available.

This study examined the mediating impact of couples' attachment behaviors on the relationship between poor quality family-of-origin experiences and marital communication quality. The couple data for this study was collected from the Relationship Evaluation (RELATE) database (see www.relate-institute.org). An Actor Partner Interdependence Model using structural equation modeling was used to evaluate 261 marriage relationships. Results indicated that the relationships between family-of-origin experiences and communication quality are significantly related, with more family-of-origin problems associated with poorer positive communication skills. When attachment behaviors (accessibility, responsiveness, and engagement) were added to the model, it significantly mediated the relationship. Implications for clinicians treating couples who present with communication problems are discussed, as are directions for future research.

Public transportation offers a crucial solution to the travel demand in light of national and global economic, energy, and environmental challenges. If implemented effectively, public transit offers an affordable, convenient, and sustainable transportation mode. Implementation of new technologies for information-harvesting may lead to more effective transit operations. This study examines the potential of automated data collection technologies to analyzing and understand the origin-destination flow patterns, which is essential for transit route planning and stop location placement. This thesis investigates the collection and analysis of data of passengers onboard San Luis Obispo Transit buses in February and March 2017 using Bluetooth (BT) and automatic passenger counter (APC) data. Five BlueMAC detectors were placed on SLO Transit buses to collect Bluetooth data. APC data was obtained from San Luis Obispo Transit. The datasets were used to establish a data processing method to exclude invalid detections, to identify and process origin and destination trips of passengers, and to make conclusions regarding passenger behavior. The filtering methods were applied to the Bluetooth data to extract counts of unique passenger information and to compare the filtered data to the ground-truth APC data. The datasets were also used to study the San Luis Obispo Downtown Farmer’s Market and its impact on transit ridership demand. The investigation revealed that after carefully employing the filters on BT data there were no consistent patterns in differences between unique passenger counts obtained from APC data and the BT data. As a result, one should be careful in employing BT data for transit OD estimation. Not every passenger enables Bluetooth or owns a Bluetooth device, so relying on the possession of Bluetooth-enabled devices may not lead to a random sample, resulting in misleading travel patterns. Based on the APC data, it was revealed that transit ridership is 40% higher during the days during which Higuera Street in Downtown San Luis Obispo is used for Farmer’s Market – a classic example of tactical urbanism. Increase in transit ridership is one of the aspects of tactical urbanism that may be further emphasized. With rapidly-evolving data collection technologies, transit data collection methods could expand beyond the traditional onboard survey. The lessons learned from this study could be expanded to provide a robust and detailed data source for transit operations and planning.