Investigations of polygonal patterned ground in continuous Antarctic permafrost by means of ground penetrating radar and electrical resistivity tomography: Some unexpected correlations

The results of a combined geophysical and geomorphological investigation of thermal-contraction-crack polygons near Gondwana station (Germany) in northern Victoria Land (Antarctica) are reported. An area of about 20,000 m2 characterized by random orthogonal polygons was investigated using integrated ground penetrating radar, electrical resistivity tomography, geomorphological surveys, and two trench excavations. The polygons are well developed only at elevations higher than 6–7 m above current sea level on Holocene-age raised beaches. It is concluded that the polygons are composite in nature because the shallow linear depressions that outline the polygons are underlain by fissures that can contain both sandy gravel and foliated ice (i.e., ice wedges) even in the same polygon network and at distances of just a few meters. Unexpectedly, most of the polygons follow the border of the raised beaches and develop in correspondence with stratigraphic layers dipping toward the sea, imaged by ground penetrating radar (GPR) profiles and interpreted as prograding layers toward the present-day shoreline

Introducción de las técnicas de modelización para el estudio de la física y de las matemáticas en los primeros cursos de las carreras técnicas

In this article we present a program of interdisciplinary practices for a first engineering course. We followed this program during the course 1996-1997, and we give several examples of the kind of exercises that we used. We also present some remarks and conclusions that we have achieved in our experience. Our purpose is to introduce a teaching strategy for Mathematics and Physics at the University level

Kaplan-Meier type survival curves for COVID-19: a health data based decision-making tool

Countries are recording health information on the global spread of COVID-19 using different methods, sometimes changing the rules after a few days. They are all publishing the number of new individuals infected, cured and dead, along with some supplementary data. These figures are often recorded in a non-uniform manner and do not match the standard definitions of these variables. However, in this paper we show that the Kaplan-Meier curves calculated with them could provide useful information about the dynamics of the disease in different countries. Our aim is to present a robust and simple model to show certain characteristics of the evolution of the dynamic process, showing that the differences of evolution among the countries is reflected in the corresponding Kaplan-Meier-type curves. We compare the curves obtained for the most affected countries so far, proposing possible interpretations of the properties that distinguish them.Comment: 12 pages, 6 figure

Introducción de las técnicas de modelización para el estudio de la física y de las matemáticas en los primeros cursos de las carreras técnicas

In this article we present a program of interdisciplinary practices for a first engineering course. We followed this program during the course 1996-1997, and we give several examples of the kind of exercises that we used. We also present some remarks and conclusions that we have achieved in our experience. Our purpose is to introduce a teaching strategy for Mathematics and Physics at the University level

MOTIPS: Automated Motif Analysis for Predicting Targets of Modular Protein Domains

<p>Abstract</p> <p>Background</p> <p>Many protein interactions, especially those involved in signaling, involve short linear motifs consisting of 5-10 amino acid residues that interact with modular protein domains such as the SH3 binding domains and the kinase catalytic domains. One straightforward way of identifying these interactions is by scanning for matches to the motif against all the sequences in a target proteome. However, predicting domain targets by motif sequence alone without considering other genomic and structural information has been shown to be lacking in accuracy.</p> <p>Results</p> <p>We developed an efficient search algorithm to scan the target proteome for potential domain targets and to increase the accuracy of each hit by integrating a variety of pre-computed features, such as conservation, surface propensity, and disorder. The integration is performed using naïve Bayes and a training set of validated experiments.</p> <p>Conclusions</p> <p>By integrating a variety of biologically relevant features to predict domain targets, we demonstrated a notably improved prediction of modular protein domain targets. Combined with emerging high-resolution data of domain specificities, we believe that our approach can assist in the reconstruction of many signaling pathways.</p

Targeted band gap creation using mixed sonic crystal arrays including resonators and rigid scatterers

Copyright (2007) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics along with the following message: The following article appeared in “Fuster García, E.; Romero García, V.; Sánchez Pérez, JV.; García-Raffi, LM. (2007). Targeted band gap creation using mixed sonic crystal arrays including resonators and rigid scatterers. Applied Physics Letters. 90:2441041-2441043” and may be found at http://dx.doi.org/10.1063/1.3040317. Authors own version of final article on e-print servers[EN] Sonic crystals are periodic structures that have acoustic band gaps centred at frequencies depending on the lattice constant of the array and on the direction of the incident acoustic wave. To eliminate this dependence, this work presents designed mixed structures constructed with rigid scatterers and resonators embedded in air. Specifically, balloons filled with a blend of air and helium were used as resonators, showing experimental evidence about the resonant behavior of an array formed with these balloons. As a result, the authors obtain full band gaps in a predetermined range of frequencies desired.This work has been supported by Spain’s Interministerial Science and Technology Commission (Contract No. 200603097 and FEDER and by the Generalitat Valenciana) (Spain) under Grant No. GV/2007/191. The authors would also like to thank the R+D+i Linguistic Assistance Office at the Universidad Politécnica of Valencia for their help in revising this letter.Fuster García, E.; Romero García, V.; Sánchez Pérez, JV.; García-Raffi, LM. (2007). Targeted band gap creation using mixed sonic crystal arrays including resonators and rigid scatterers. Applied Physics Letters. 90(24):2441041-2441043. https://doi.org/10.1063/1.2748853S24410412441043902

Textural variations in Neogene pelagic carbonate ooze at DSDP Site 593, southern Tasman Sea, and their paleoceanographic implications

Changes in Neogene sediment texture in pelagic carbonate-rich oozes on the Challenger Plateau, southern Tasman Sea, are used to infer changes in depositional paleocurrent velocities. The most obvious record of textural change is in the mud:sand ratio. Increases in the sand content are inferred to indicate a general up-core trend towards increasing winnowing of sediments resulting from increasing flow velocity of Southern Component Intermediate Water (SCIW), the forerunner of Antarctic Intermediate Water. In particular, the intervals c. 19-14.5 Ma, c. 9.5-8 Ma, and after 5 Ma are suggested to be times of increased SCIW velocity and strong sediment winnowing. Within the mud fraction, the fine silt to coarse clay sizes from 15.6 to 2 µm make the greatest contribution to the sediments and are composed of nannofossil plates. During extreme winnowing events it is the fine silt to very coarse clay material (13-3 µm) within this range that is preferentially removed, suggesting the 10 µm cohesive silt boundary reported for siliciclastic sediments does not apply to calcitic skeletal grains. The winnowed sediment comprises coccolithophore placoliths and spheres, represented by a mode at 4-7 µm. Further support for seafloor winnowing is gained from the presence in Hole 593 of a condensed sedimentary section from c. 18 to 14 Ma where the sand content increases to c. 20% of the bulk sample. Associated with the condensed section is a 6 m thick orange unit representing sediments subjected to particularly oxygen-rich, late early to early middle Miocene SCIW. Together these are inferred to indicate increased SCIW velocity resulting in winnowed sediment associated with faster arrival of oxygen-rich surface water subducted to form SCIW. Glacial development of Antarctica has been recorded from many deep-sea sites, with extreme glacials providing the mechanism to increase watermass flow. Miocene glacial zones Mi1b-Mi6 are identified in an associated oxygen isotope record from Hole 593, and correspond with times of particularly invigorated paleocirculation, bottom winnowing, and sediment textural changes

Mitigation of plasma-wall interactions with low-Z powders in DIII-D high confinement plasmas

Experiments with low-Z powder injection in DIII-D high confinement discharges demonstrated increased divertor dissipation and detachment while maintaining good core energy confinement. Lithium (Li), boron (B), and boron nitride (BN) powders were injected in high-confinement mode plasmas ($I_p=$1 MA, $B_t=$2 T, $P_{NB}=$6 MW, $\langle n_e\rangle=3.6-5.0\cdot10^{19}$ m$^{-3}$) into the upper small-angle slot (SAS) divertor for 2-s intervals at constant rates of 3-204 mg/s. The multi-species BN powders at a rate of 54 mg/s showed the most substantial increase in divertor neutral compression by more than an order of magnitude and lasting detachment with minor degradation of the stored magnetic energy $W_{mhd}$ by 5%. Rates of 204 mg/s of boron nitride powder further reduce ELM-fluxes on the divertor but also cause a drop in confinement performance by 24% due to the onset of an $n=2$ tearing mode. The application of powders also showed a substantial improvement of wall conditions manifesting in reduced wall fueling source and intrinsic carbon and oxygen content in response to the cumulative injection of non-recycling materials. The results suggest that low-Z powder injection, including mixed element compounds, is a promising new core-edge compatible technique that simultaneously enables divertor detachment and improves wall conditions during high confinement operation

Detección y prevención de las malas prácticas y la corrupción desde la perspectiva de las matemáticas

[EN] In this article reference is made to the possible use of mathematical tools in the prevention and detection of fraud. The detection of fraud is considered one of the biggest challenges for public administrations. Beyond the processes of inspection and auditing, society not only requires of its administrators the prosecution of the crime but also its prevention, to avoid not only the economic damage, but also the high price that in terms of lack of services end up paying citizens, who have previously fulfilled their obligations by contributing to public coffers.[ES] En este artículo se hace referencia a la posible utilización de herramientas matemáticas en la prevención y detección del fraude. La detección del fraude se plantea como uno de los mayores desafíos de las administraciones públicas. Más allá de los procesos de inspección y auditoría, la sociedad no sólo exige de sus administradores la persecución del delito sino también su prevención, para evitar, no sólo el daño económico, sino también el alto precio que en términos de carencia de servicios acaban pagando los ciudadanos, quienes previamente han cumplido con sus obligaciones contribuyendo a las arcas públicas.Calabuig, JM.; Falciani, H.; Ferrer Sapena, A.; García-Raffi, LM.; Raso, E.; Sánchez Del Toro, I.; Sánchez Pérez, EA. (2018). Detección y prevención de las malas prácticas y la corrupción desde la perspectiva de las matemáticas. Revista Internacional de Transparencia e Integridad. (8):1-8. http://hdl.handle.net/10251/123867S18