Lithospheric structure in the Pacific geoid

The high degree and order SEASAT geoid in the central Pacific correlates closely with the structure of the cooling lithosphere. Relative changes in plate age across major fracture zones in relatively young seafloor frame the east-west trending pattern formed by the geoid anomalies. The field removal in bathymetry corresponds to removal of some of the low degree and order geoidal components, the step like structure across fracture zones is also removed. The regional thermal subsidence was removed from the bathymetry by subtracting a mean subsidence surface from the observed bathymetry. This produces a residual bathymetry map analogous to the usual residual depth anomaly maps. The residual bathymetry obtained in this way contains shallow depths for young seafloor, and larger depths for older seafloor, thus retaining the structure of the lithosphere while removing the subsidence of the lithosphere

Rapid transition from continental breakup to igneous oceanic crust in the South China Sea

Continental breakup represents the successful process of rifting and thinning of the continental lithosphere, leading to plate rupture and initiation of oceanic crust formation. Magmatism during breakup seems to follow a path of either excessive, transient magmatism (magma-rich margins) or of igneous starvation (magma-poor margins). The latter type is characterized by extreme continental lithospheric extension and mantle exhumation prior to igneous oceanic crust formation. Discovery of magma-poor margins has raised fundamental questions about the onset of ocean-floor type magmatism, and has guided interpretation of seismic data across many rifted margins, including the highly extended northern South China Sea margin. Here we report International Ocean Discovery Program drilling data from the northern South China Sea margin, testing the magma-poor margin model outside the North Atlantic. Contrary to expectations, results show initiation of Mid-Ocean Ridge basalt type magmatism during breakup, with a narrow and rapid transition into igneous oceanic crust. Coring and seismic data suggest that fast lithospheric extension without mantle exhumation generated a margin structure between the two endmembers. Asthenospheric upwelling yielding Mid-Ocean Ridge basalt-type magmatism from normal-temperature mantle during final breakup is interpreted to reflect rapid rifting within thin pre-rift lithosphere

Automated Network Service Scaling in NFV: Concepts, Mechanisms and Scaling Workflow

Next-generation systems are anticipated to be digital platforms supporting innovative services with rapidly changing traffic patterns. To cope with this dynamicity in a cost-efficient manner, operators need advanced service management capabilities such as those provided by NFV. NFV enables operators to scale network services with higher granularity and agility than today. For this end, automation is key. In search of this automation, the European Telecommunications Standards Institute (ETSI) has defined a reference NFV framework that make use of model-driven templates called Network Service Descriptors (NSDs) to operate network services through their lifecycle. For the scaling operation, an NSD defines a discrete set of instantiation levels among which a network service instance can be resized throughout its lifecycle. Thus, the design of these levels is key for ensuring an effective scaling. In this article, we provide an overview of the automation of the network service scaling operation in NFV, addressing the options and boundaries introduced by ETSI normative specifications. We start by providing a description of the NSD structure, focusing on how instantiation levels are constructed. For illustrative purposes, we propose an NSD for a representative NS. This NSD includes different instantiation levels that enable different ways to automatically scale this NS. Then, we show the different scaling procedures the NFV framework has available, and how it may automate their triggering. Finally, we propose an ETSI-compliant workflow to describe in detail a representative scaling procedure. This workflow clarifies the interactions and information exchanges between the functional blocks in the NFV framework when performing the scaling operation.Comment: This work has been accepted for publication in the IEEE Communications Magazin

Regions of Diversity 8, 9 and 13 contribute to Streptococcus pneumoniae virulence

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is the leading cause of community-acquired pneumonia. Previously, using comparative genomic analyses, 13 regions of genomic plasticity have been identified in the <it>S. pneumoniae </it>genome. These "Regions of Diversity" (RDs) accounted for half the genomic variation observed amongst all pneumococci tested, moreover, were determined to encode a variety of putative virulence factors. To date, genes within 5 RDs have been unequivocally demonstrated to contribute to <it>S. pneumoniae </it>virulence. It is unknown if the remaining RDs also contribute to virulence.</p> <p>Results</p> <p>Using allelic exchange, we created <it>S. pneumoniae </it>mutants that were deficient in RD2, 5, 7, 8, 9, 12 and 13. Mutants deficient in RD8, 9 and 13 were attenuated in a mouse model of disease. RD8 is 40,358 nucleotides in length and encodes 37 genes. Using a panel of isogenic mutants, we determined that RD8b3 is the operon within RD8 that is responsible for virulence. Mice infected with mutants deficient in RD8, RD8b3, RD9 and RD13 had significantly less bacteria in the blood two days after intranasal challenge and improved survival over time versus mice infected with wild type. In all instances mutants colonized the nasopharynx at levels equivalent to wild type.</p> <p>Conclusion</p> <p>Genes within RD1, 3, 4, 6, and 10 have previously been shown to contribute to virulence. This study demonstrates that genes within RD8, 9 and 13 also contribute to virulence. The ability of mutants deficient in RD2, 5, 7, 8, 9, 12, and 13 to colonize the nasopharynx indicates that genes within these RDs are not required for asymptomatic carriage. Nonetheless, the observation that mutants deficient in RD8b3, 9 and 13 are attenuated indicates that genes within these loci are necessary for spread of the bacteria beyond the nasopharynx to normally sterile sites.</p

Blood Lactate Response to Active Recovery in Athletes vs. Non-Athletes

Previous research has indicated an optimal intensity for active recovery following a bout of exercise for the removal of blood lactate to be at 80% of the individual’s lactate threshold. However, these previous research studies have relied primarily on highly trained athletes. Therefore, the 80% of lactate threshold might not be the optimal intensity for non-athlete populations attempting to recover from lactate producing exercise. Purpose: To investigate the acute blood lactate response during active recovery at 80% of lactate threshold for athletes vs. non-athletes following a vigorous bout of activity. Methods: Apparently healthy and active young adults (N=16, 56% male, 21±1 yr, BMI: 26.5±3.6 kg/m2, SBP: 122±13 mmHg, DBP: 71±8 mmHg) were enrolled in a cohort study design that separates subjects into highly trained collegiate athletes (participating in a NCAA sport) and non-athletes. Each subject had two study visits. Visit one included collection of subject characteristics including baseline values of blood pressure and heart rate via an automated device, and blood lactate via finger stick. Additionally, subjects underwent a Bruce Protocol on a treadmill to determine lactate threshold as well as VO2max. Visit two consisted of a treadmill warm up at 5 mph and 0% incline followed by a brief running protocol at 90% of their VO2max for 5 minutes. Immediately following the 5 minutes, subjects engaged in active recovery at 80% of the subject’s lactate threshold until baseline lactate levels were reached or until 32 minutes of active recovery was completed. Measurements of heart rate and blood lactate were taken at rest, post-warm up, post-exercise bout, and every four minutes during active recovery for day two. Area under the curve (AUC) was calculated for blood lactate and general mixed linear modeling was used to compare AUC for athletes vs. non-athletes while Cohen’s d was calculated to determine effect size. Post hoc analysis of individual time points used Bonferroni adjustment. Alpha level was set at p\u3c0.05. Results: There was a significant difference in overall lactate (b= -109.8 mmol/L, p\u3c0.001, d= 2.32) as well as at each time point during the active recovery (all p\u3c0.005). There was also a significant difference in overall heart rate in favor of athletes having lower heart rate response throughout (b= -14 bpm, p=0.003, d= 0.164). When individual time points were analyzed, there was a significant difference in heart rate at time point 7 (b=-20 bpm, p\u3c0.005, d= 2.243), time point 8 (b=-21 bpm, p\u3c0.005, d= 2.305), and at time point 10 (b=-18.533 bpm, p\u3c0.005, d= 2.080) in favor of lower heart rate for athletes. Conclusion: Active Recovery at 80% of lactate threshold demonstrated a significant difference in the removal of lactate for athletes compared to non-athletes. Future research should investigate the most efficient workload for the removal of blood lactate in non-athletes, potentially an intensity that lowers non-athletes heart rates more than the intensity used in this study

Starburst galaxies in the COSMOS field : clumpy star-formation at redshift 0 < z <0.5

This work has been funded by the Spanish MINECO, Grant ESTALLIDOS, AYA2013-47742-C4-2P and AYA2010-21887-C04-04. J.M.A. acknowledges support from the European Research Council Starting Grant SEDMorph (P.I. V. Wild). R.H.G. acknowledges the FPI grant from MINECO within ESTALLIDOS project.Context. At high redshift, starburst galaxies present irregular morphologies with 10-20% of their star formation occurring in giant clumps. These clumpy galaxies are considered the progenitors of local disk galaxies. To understand the properties of starbursts at intermediate and low redshift, it is fundamental to track their evolution and the possible link with the systems at higher z. Aims. We present an extensive, systematic, and multiband search and analysis of the starburst galaxies at redshift (0 1010. We classify galaxies into three main types, depending on their HST morphology: single knot (Sknot), single star-forming knot plus diffuse light (Sknot+diffuse), and multiple star-forming knots (Mknots/clumpy) galaxy. We found a fraction of Mknots/clumpy galaxy fclumpy = 0.24 considering out total sample of starburst galaxies up to z ∼ 0.5. The individual star-forming knots in our sample follows the same L(Hα) vs. size scaling relation as local giant HII regions. However, they slightly differ from the one provided using samples at high redshift. This result highlights the importance of spatially resolving the star-forming regions for this kind of study. Star-forming clumps in the central regions of Mknots galaxies are more massive, and present higher star formation rates, than those in the outskirts. This trend is less clear when we consider either the mass surface density or surface star formation rate. Sknot galaxies do show properties similar to both dwarf elliptical and irregulars in the surface brightness (μ) versus Mhost diagram in the B-band, and to spheroidals and ellipticals in the μ versus Mhost diagram in the V-band. Conclusions. The properties of our star-forming knots in Sknot+diffuse and Mknots/clumpy galaxies support the predictions of recent numerical simulations claiming that they have been produced by violent disk instabilities. We suggest that the evolution of these knots means that large and massive clumps at the galaxy centers represent the end product of the coalescence of surviving smaller clumps from the outskirts. Our results support this mechanism and make it unlikely that mergers are the reason behind the observed starburst knots. Sknot galaxies might be transitional phases of the Blue Compact Dwarfs (BCD) class, with their properties consistent with spheroidal-like, but blue structures.Publisher PDFPeer reviewe

Las edades del Cenozoico mamalífero de la Argentina, con especial atención a aquellas del territorio bonaerense

La primera parte del trabajo ha sido dedicada a discutir los problemas de la Clasificaci&oacute;n, Terminolog&iacute;a y Nomenclatura estratigr&aacute;fica en la Argentina. Sucintamente se analizan las dificultades que los estrat&iacute;grafos argentinos actuales encuentran en estos aspectos por la falta de claridad que ha regido la distinci&oacute;n de las unidades y los nombres aplicados a las rocas, a las faunas y al tiempo. Como en los EE. UU. se han vivido situaciones semejantes, se analizan las proposiciones de su C&oacute;digo Estratigr&aacute;fico, y su aplicabilidad a la Estratigraf&iacute;a de Argentina. Especialmente se analizan las exigencias formales de la clasificaci&oacute;n cronoestratigr&aacute;fica y geocronol&oacute;gica, y la practicabilidad de sus equivalencias. Dado que en la distinci&oacute;n de las unidades cronoestratigr&aacute;ficas y geocronol&oacute;gicas no se han seguido en la mayor&iacute;a de los casos las proposiciones del Congreso Geol&oacute;gico Internacional de Copenhague, de 1961, ni las del mencionado C&oacute;digo norteamericano, los autores eluden premeditadamente el uso de la clasificaci&oacute;n cronoestratigr&aacute;fica y s&oacute;lo aplican la clasificaci&oacute;n geocronol&oacute;gica. Pero al reconocer las Edades del Cenozoico mamal&iacute;fero de Argentina lo hacen con el significado que le diera en los EE.UU. Savage, es decir, Edades-mam&iacute;fero (&ldquo;Land-Mammals Ages&rdquo;), se&ntilde;alando que su correspondencia con las Edades reconocidas seg&uacute;n las exigencias formales vigentes y su equivalencia con los Pisos respectivos ser&aacute;n determinadas por el avance de los estudios, y por el sometimiento m&aacute;s riguroso a los c&aacute;nones estratigr&aacute;ficos. La segunda parte del trabajo se dedica al an&aacute;lisis de los criterios que se han seguido para reconocer las Edades-mam&iacute;fero, y se analizan las bases de sus correlaciones continentales y extracontinentales, y por ellas se- las asigna a las &Eacute;pocas universalmente reconocidas. Las conclusiones se sintetizan en dos cuadros: uno de todas las Edades-mam&iacute;fero de Argentina y su correlaci&oacute;n con las Edades de Am&eacute;rica del Norte y Europa, y otro de las Edades del Cenozoico mamal&iacute;fero representadas en la provincia de Buenos Aires, indicando la asignaci&oacute;n a ellas de las unidades litoestratigr&aacute;ficas fundamentales reconocidas hasta el momento. Finalmente se incluye una lista sistem&aacute;tica de los taxa de mam&iacute;feros de cada Edad, y se se&ntilde;alan para cada una de ellas los &ldquo;f&oacute;siles gu&iacute;as&rdquo; y los &ldquo;f&oacute;siles caracter&iacute;sticos&rdquo;, indicando adem&aacute;s aquellos taxa que aparecen y desaparecen en cada una.The first part of the paper deals with the stratigraphical classification, terminology and nomenclature of units specially those mammal-bearing of Argentina. Difficulty is emphasized in applying stratigraphical codes in connexion with the stages and ages. Savage criteria is here adopted re- cognizing only Land-Mammal Ages. The second part analizes the criteria used for recognizing the Argentine Land-Mammals Ages specially those of the Province of Buenos Aires. An attempt is made to correlate them with those of Europe and North America. Finally a sistematic list ending with the genus with indication of &ldquo;guide fossils&rdquo; and &ldquo;characteristic fossils&rdquo;, etc., of each Land-Mammal Ages of the Province of Buenos Aires is displayed