Projected distributions of Southern Ocean albatrosses, petrels and fisheries as a consequence of climatic change

Given the major ongoing influence of environmental change on the oceans, there is a need to understand and predict the future distributions of marine species in order to plan appropriate mitigation to conserve vulnerable species and ecosystems. In this study we use tracking data from seven large seabird species of the Southern Ocean (black-browed albatross Thalassarche melanophris, grey-headed albatross T. chrysostoma, northern giant petrel Macronectes halli, southern giant petrel M. giganteus, Tristan albatross Diomedea dabbenena, wandering albatross D. exulans and white-chinned petrel Procellaria aequinoctialis, and on fishing effort in two types of fisheries (characterised by low or high-bycatch rates), to model the associations with environmental variables (bathymetry, chlorophyll-a concentration, sea surface temperature and wind speed) through ensemble species distribution models. We then projected these distributions according to four climate change scenarios built by the Intergovernmental Panel for Climate Change for 2050 and 2100. The resulting projections were consistent across scenarios, indicating that there is a strong likelihood of poleward shifts in distribution of seabirds, and several range contractions (resulting from a shift in the northern, but no change in the southern limit of the range in four species). Current trends for southerly shifts in fisheries distributions are also set to continue under these climate change scenarios at least until 2100; some of these may reflect habitat loss for target species that are already over-fished. It is of particular concern that a shift in the distribution of several highly threatened seabird species would increase their overlap with fisheries where there is a high-bycatch risk. Under such scenarios, the associated shifts in distribution of seabirds and increases in bycatch risk will require much-improved fisheries management in these sensitive areas to minimise impacts on populations in decline

Boson gas in a periodic array of tubes

We report the thermodynamic properties of an ideal boson gas confined in an infinite periodic array of channels modeled by two, mutually perpendicular, Kronig-Penney delta-potentials. The particle's motion is hindered in the x-y directions, allowing tunneling of particles through the walls, while no confinement along the z direction is considered. It is shown that there exists a finite Bose- Einstein condensation (BEC) critical temperature Tc that decreases monotonically from the 3D ideal boson gas (IBG) value $T_{0}$ as the strength of confinement $P_{0}$ is increased while keeping the channel's cross section, $a_{x}a_{y}$ constant. In contrast, Tc is a non-monotonic function of the cross-section area for fixed $P_{0}$. In addition to the BEC cusp, the specific heat exhibits a set of maxima and minima. The minimum located at the highest temperature is a clear signal of the confinement effect which occurs when the boson wavelength is twice the cross-section side size. This confinement is amplified when the wall strength is increased until a dimensional crossover from 3D to 1D is produced. Some of these features in the specific heat obtained from this simple model can be related, qualitatively, to at least two different experimental situations: $^4$He adsorbed within the interstitial channels of a bundle of carbon nanotubes and superconductor-multistrand-wires Nb$_{3}$Sn.Comment: 9 pages, 10 figures, submitte

Identification of New Wheat Genes for Durable Resistance of Adult Plants to Yellow Rust (Puccinia striiformis Westend. f. sp. Ericks)

Yellow rust is a wheat disease caused by Puccinia striiformis, this pathogen causes economic losses in susceptible materials, which represent up to 70% of wheat varieties. Currently, the incorporation of genetic resistance through molecular tools, is a process used in the generation of new varieties resistant to this pathogen. A strategy employed to identify genes involved in the resistance to yellow rust is to screen differential EST obtained by suppressive subtractive hybridization. In this research, cDNA was extracted from healthy and inoculated plants from the resistant line V-26 from INIFAP. A set of 200 differentially expressed EST were cloned and sequenced, and 31 of them were selected for expression profile analysis by RT-PCR; additionally, with the aim of validate RT-PCR results, five genes were selected for RT-qPCR analysis in genotypes inoculated by P. striiformis. The results showed high levels of expression of selected genes in genotypes classified as resistant in the field conditions (21, 143, 230, 242, 261 and 277), while in the susceptible genotype 16, few genes were induced by the rust. Expression profiles confirmed significant differences between resistant and susceptible lines

Growth chemistry and electrical performance of ultrathin alumina formed by area selective vapor phase infiltration

The growth chemistry and electrical performance of 5 nm alumina films, fabricated via the area-selective vapor phase infiltration (VPI) of trimethylaluminum into poly(2-vinylpyridine), are compared to a conventional plasma enhanced atomic layer deposition (PEALD) process. The chemical properties are assessed via energy dispersive X-ray spectroscopy and hard X-ray photoelectron spectroscopy measurements, while current – voltage dielectric breakdown and capacitance – voltage analysis is undertaken to provide electrical information of these films for the first time. The success and challenges in dielectric formation via polymer VPI, the compatibility of pyridine in such a role, and the ability of the unique and rapid grafting-to polymer brush method in forming coherent metal oxides is evaluated. It was found that VPI made alumina fabricated at temperatures between 200 and 250 °C had a consistent breakdown electrical field, with the best performing devices possessing a к value of 5.9. The results indicate that the VPI approach allows for the creation of alumina films that display dielectric properties of a comparable quality to conventional PEALD grown films

tecnología cmos: avances y perspectivas cmos

Modern electronics, known as microelectronics, has evolved astonishingly in the last decades thanks to scientic and technological advances. In the early 1960, Metal-Oxide-Semiconductor Field Effect Transistors were developed, followed by Complementary Metal-Oxide-Semiconductor technology, giving the eld of microelectronics an amazing improvement. Since then, the semiconductor industry has been guided by the continuous reduction of the transistor dimensions used in integrated circuits, allowing the development of the current state of technology with lengths down to tens of nanometers. As the transistor dimensions are shrunk, different phenomena appear that cause performance degradation of the devices. Hence, technological alternatives have been proposed in order to continue with the progress observed in the last decades. In this context, Multiple Gate Field Effect Transistors appears as a viable alternative to reach sub-10nm nodes. TECNOLOGÍA CMOS: AVANCES Y PERSPECTIVAS CMOS TECHNOLOGY: ADVANCES AND PERSPECTIVES However, in order to keep such progress for future technology nodes, it is necessary to solve a number of technological and scientic challenges, due to the difculty of fabricating transistors at such scale and the physical phenomena presented. In this contribution, a revision of the main keystones of microelectronics, stressing the Complementary Metal-Oxide-Semiconductor technology case, as well as the main challenges for future technology nodes are addressed.La electrónica moderna, conocida como microelectrónica, ha evolucionado de manera notable en las últimas décadas gracias a diversos progresos científicos y tecnológicos. Durante los primeros años de la década de 1960, se desarrollaron los transistores de efecto de campo Metal-Óxido-Semiconductor y con ellos la tecnología Metal-Óxido-Semiconductor Complementaria, lo cual dio un impulso sin precedentes a la microelectrónica. Desde aquellos años, el avance observado ha sido guiado por la continua reducción de las dimensiones de los transistores utilizados en la fabricación de los circuitos integrados, llegando a tecnologías actuales cuyas dimensiones son del orden de decenas de nanómetros. A medida que se reducen las dimensiones de los transistores, comienzan a aparecer un conjunto de fenómenos que degradan su funcionamiento. Por ello, la tecnología ha buscado diferentes alternativas a fin de continuar con el progreso observado. En este contexto, los transistores de efecto de campo de múltiples compuertas aparecen como una alternativa viable para guiar a la tecnología hacia los dispositivos de menos de 10 nm (sub-10 nm)