Metagenomics Reveals Microbial Diversity and Metabolic Potentials of Seawater and Surface Sediment From a Hadal Biosphere at the Yap Trench

Hadal biosphere represents the deepest part of the ocean with water depth >6,000 m. Accumulating evidence suggests the existence of unique microbial communities dominated by heterotrophic processes in this environment. However, investigations of the microbial diversity and their metabolic potentials are limited because of technical constraints for sample collection. Here, we provide a detailed metagenomic analysis of three seawater samples at water depths 5,000–6,000 m below sea level (mbsl) and three surface sediment samples at water depths 4,435–6,578 mbsl at the Yap Trench of the western Pacific. Distinct microbial community compositions were observed with the dominance of Gammaproteobacteria in seawater and Thaumarchaeota in surface sediment. Comparative analysis of the genes involved in carbon, nitrogen and sulfur metabolisms revealed that heterotrophic processes (i.e., degradation of carbohydrates, hydrocarbons, and aromatics) are the most common microbial metabolisms in the seawater, while chemolithoautotrophic metabolisms such as ammonia oxidation with the HP/HB cycle for CO2 fixation probably dominated the surface sediment communities of the Yap Trench. Furthermore, abundant genes involved in stress response and metal resistance were both detected in the seawater and sediments, thus the enrichment of metal resistance genes is further hypothesized to be characteristic of the hadal microbial communities. Overall, this study sheds light on the metabolic versatility of microorganisms in the Yap Trench, their roles in carbon, nitrogen, and sulfur biogeochemical cycles, and how they have adapted to this unique hadal environment

<b>Non-criteria and Criteria Antiphospholipid Antibodies and Their Association with Pregnancy Outcomes in Women with a History of Miscarriage: A Retrospective Study</b>

Non-criteria and Criteria Antiphospholipid Antibodies and Their Association with Pregnancy Outcomes in Women with a History of Miscarriage</p

Facilitating Real-Time Graph Mining

Real-time data processing is increasingly gaining momentum as the preferred method for analytical applications. Many of these applications are built on top of large graphs with hundreds of millions of vertices and edges. A fundamental requirement for real-time processing is the ability to do incremental processing. However, graph algorithms are inherently difficult to compute incrementally due to data dependencies. At the same time, devising incremental graph algorithms is a challenging programming task. This paper introduces GraphInc, a system that builds on top of the Pregel model and provides efficient incremental processing of graphs. Importantly, GraphInc supports incremental computations automatically, hiding the complexity from the programmers. Programmers write graph analytics in the Pregel model without worrying about the continuous nature of the data. GraphInc integrates new data in real-time in a transparent manner, by automatically identifying opportunities for incremental processing. We discuss the basic mechanisms of GraphInc and report on the initial evaluation of our approach

Role of Chemical Heterogeneities on Oxygen Reduction Kinetics on the Surface of Thin Film Cathodes

We investigated the effects of annealing and A-site stoichiometry on the surface heterostructures at (La0.8Sr0.2)yMnO3 (LSM, y≤1) dense thin films. While annealing at high temperatures induces cation segregation on LSM, A-site deficiency is hypothesized to reduce the level of Sr enrichment on the surface by providing more space in the bulk of LSM for this relatively large cation. Localized chemical analysis by Auger electron spectroscopy revealed the strong enrichment of Sr and Zr in annealing-induced particles on LSM surfaces. By systematically varying y from 1.0 to 0.95, A-site deficiency in LSM films was shown to suppress Sr segregation and decrease the density of these secondary phases on annealed LSM surfaces, suggesting a higher chemical stability of LSM surfaces with A-site deficiency. Our results contribute to understanding the elastic energy contributions to cation segregation on perovskite cathode surfaces, and to elucidating the role of surface chemical heterogeneities to the ORR kinetics.United States. Dept. of Energy. Office of Fossil Energy (Grant DE-NT0004117

Médias et pouvoir au Sénégal depuis l'indépendance (1960)

Ce travail examine les rapports entre médias et pouvoir au Sénégal depuis l'indépendance en 1960. Les médias et le pouvoir ont connu des relations ambivalentes, plus ou moins conflictuelles. Cette situation est liée au processus de démocratisation du pays qui n'a pas été linéaire. De 1856 à 1960, il faut distinguer deux cas : les quatre communes (Gorée, Rufisque, Saint-Louis et Dakar) où s'applique la loi française, et le reste du pays où le code de l'indigénat fait office de loi. Dans le premier cas où la liberté de la presse existe plus ou moins, c'est le bouillonnement politique qui favorise l'émergence des médias, notamment la presse politique partisane. Sous le régime de Léopold Sédar Senghor (1960-1980), la presse plurielle héritée de la colonisation a cédé la place à un monopole médiatique avec l'instauration du parti unique malgré l existence de quelques téméraires qui s'aventuraient à créer des journaux. Abdou Diouf (1981-2000) a décrété le multipartisme entraînant un foisonnement de la presse. Mais le tournant a été la deuxième moitié des années 1980 où la presse dite indépendante va prendre place dans le paysage médiatique. Des conflits ont été notés entre son régime et les médias, même si cela a été plus ou moins mesuré. Sous le régime d'Abdoulaye Wade, depuis 2000, le nombre de médias s'est accru. Les télévisions privées ont fait irruption. Mais Abdoulaye Wade innove dans les rapports entre médias et pouvoir par ses attaques contre les médias de son pays. C'est dans ce contexte que ce travail offre la possibilité de s'interroger sur l'éventualité d'un nouveau paysage médiatique dont les règles vont clairement être définies et respectées au Sénégal par l'ensemble des acteurs. C'est dans cette perspective qu'il est proposé de favoriser l'éclosion d'une presse régionale pour mieux accompagner la démocratie locale.This work examines the relationship between media and authority in Senegal since the independence in 1960, after a historical review. The media and authority have had ambivalent relationships. Sometimes stable, sometimes conflicting. This relationship is related to the democratization process of the country that has not been linear. From 1856 to 1960, there were two distinguished cases: the four municipalities, that are Goree, Rufique, Saint-Louis and Dakar, where French law and the rest of the country native code were applied as law.. In the first case where the press freedom more or less exists, the political turmoil has led to the media emergence, particularly in partisan politics press. Under Leopold Sedar Senghor s regime (1960-1980), the plural press inherited from the colonialism, gave a way to a monopoly media with the introduction of a single party. Even if few reckless people ventured to create newspapers, the multiparty decreed by President Abdou Diouf (1981-2000) led to a proliferation of the press. However, the turning point was the mid-1980 s, when the so-called independent press founded by journalists, appeared. Under Abdou Diouf regime, conflicts were noted between his regime and the media, although it was more or less moderate. Since 2000, under Abdoulaye Wade regime, the number of media has increased. Private television sprung. The new relationship between media and authority under Abdoulaye Wade reign, is that ihe is the one who confronted the media of his country. It is in this perspective that this work examines a new media landscape potential where the rules are clearly defined and respected. It is also proposed to promote a regional press emergence.PARIS-CUJAS-BU Droit (751052119) / SudocSudocFranceF

Strain Effects on the Surface Chemistry of La0.7Sr0.3MnO3

We report on the mechanistic effects of epitaxial strain on the surface chemistry, in particular the segregation of Sr cations on La0.7Sr0.3MnO3 (LSM) model dense thin films. Our results show that the LSM film surfaces are layered and exhibit strain-dependent nanoscale lateral structures. All surfaces examined here were Sr-rich. X-ray photoelectron spectroscopy shows a larger Sr segregation tendency for the tensile strained LSM films. This result is in good agreement with our first principles-based calculations, which predict lower Sr segregation energy on the tensile strained LSM surface. Our findings suggest the importance of lattice strain as a key parameter to tune the surface chemistry for facilitating oxygen reduction kinetics on transition metal perovskite cathode surfaces for solid oxide fuel cells.United States. Dept. of Energy (Office of Fossil Energy, Grant No. DE–NT0004117)United States. Dept. of Energy (Basic Energy Sciences, Grant No. DE-SC0002633)National Science Foundation (U.S.) (TeraGrid Advanced Support Program, Grant No. TG–ASC090058

Cation Size Mismatch and Charge Interactions Drive Dopant Segregation at the Surfaces of Manganite Perovskites

Cation segregation on perovskite oxide surfaces affects vastly the oxygen reduction activity and stability of solid oxide fuel cell (SOFC) cathodes. A unified theory that explains the physical origins of this phenomenon is therefore needed for designing cathode materials with optimal surface chemistry. We quantitatively assessed the elastic and electrostatic interactions of the dopant with the surrounding lattice as the key driving forces for segregation on model perovskite compounds, LnMnO(3) (host cation Ln = La, Sm). Our approach combines surface chemical analysis with X-ray photoelectron and Auger electron spectroscopy on model dense thin films and computational analysis with density functional theory (DFT) calculations and analytical models. Elastic energy differences were systematically induced in the system by varying the radius of the selected dopants (Ca, Sr, Ba) with respect to the host cations (La, Sm) while retaining the same charge state. Electrostatic energy differences were introduced by varying the distribution of charged oxygen and cation vacancies in our models Varying the oxygen chemical potential in our experiments induced changes in both the elastic energy and electrostatic interactions. Our results quantitatively demonstrate that the mechanism of dopant segregation on perovskite oxides includes both the elastic and electrostatic energy contributions. A smaller size mismatch between the host and dopant cations and a chemically expanded lattice were found to reduce the segregation level of the dopant and to enable more stable cathode surfaces Ca doped LaMnO3 was found to have the most stable surface composition with the least cation segregation among the compositions surveyed. The diffusion kinetics of the larger dopants, Ba and Sr, was found to be slower and can kinetically trap the segregation at reduced temperatures despite the larger elastic energy driving force. Lastly, scanning probe image contrast showed that the surface chemical heterogeneities made of dopant oxides upon segregation were electronically insulating. The consistency between the results obtained from experiments, DFT calculations, and analytical theory in this work provides a predictive capability to tailor the cathode surface compositions for high-performance SOFCs.11Nsciescopu