Linear convergence in time-varying generalized Nash equilibrium problems

We study generalized games with full row rank equality constraints and we provide a strikingly simple proof of strong monotonicity of the associated KKT operator. This allows us to show linear convergence to a variational equilibrium of the resulting primal-dual pseudo-gradient dynamics. Then, we propose a fully-distributed algorithm with linear convergence guarantee for aggregative games under partial-decision information. Based on these results, we establish stability properties for online GNE seeking in games with time-varying cost functions and constraints. Finally, we illustrate our findings numerically on an economic dispatch problem for peer-to-peer energy markets

Dinámica espacio-temporal de la relación entre el clima y el funcionamiento de los ecosistemas en Patagonia Norte

En el Capítulo 1 se provee el marco teórico y los objetivos planteados en este estudio. En elCapítulo 2 se presentan las grillas de precipitación y temperatura hechas a partir de unarecopilación de datos mensuales en la región. Se compilaron 218 y 114 registros deprecipitaciónytemperaturarespectivamente,provenientesdeinstitucionesgubernamentales y privadas de la región. Estos datos fueron interpolados mediante latécnica de co-kriging para obtener grillas de precipitación y temperatura de 20 km x 20 kmcubriendo el norte de la Patagonia desde 63° a 75° longitud Oeste y 35° a 45° latitud Sur.Estas nuevas grillas (Grillado Climático para Patagonia Norte, o GCPN) representan lasvariaciones de los rasgos espaciales en los campos medios de temperatura y precipitaciónde una manera más realista que las grillas climáticas globales disponibles en la actualidad.También se comparó el desempeño de estas grillas con otras grillas climáticas globales deuso común en la región. A partir del trabajo realizado en este capítulo se ha publicado unartículo científico en una revista indexada (DOI: 10.1007/s13351-015-5058-y).En el capítulo 3 se analizó la variabilidad espacial y temporal de la precipitación y latemperatura (utilizando las grillas presentadas en el capítulo 2) y su relación con fenómenosclimáticos de gran escala. La variabilidad espacio-temporal de los campos de precipitacióny temperatura a escala regional fue establecida aplicando un Análisis de ComponentesPrincipales (ACP) a los datos grillados. Una vez determinados los patrones dominantes, seexploraron los forzantes del sistema climático a escala hemisférica y global asociados a lavariabilidad en la temperatura y precipitación en el norte de la Patagonia. A grandes rasgos,el análisis de componentes principales aplicado a las series de precipitación y temperaturaidentificó cuatro grandes patrones de variabilidad temporal en la región. El patrón asociadoal sector noroeste de la región presenta un clima tipo mediterráneo. El patrón asociado alsector Este y Noreste coincide con el clima frio semiárido. El patrón asociado al sector Sury Sudeste coincide con el clima árido frio, mientras que el patrón asociado a la región Sur ySudoeste coincide con la región de clima oceánico. La comparación de estos patrones dominantes de variabilidad en la temperatura y laprecipitación sobre el norte de la Patagonia con índices de circulación océano/atmosferaarrojó algunas relaciones de interés. Por ejemplo, existe una relación negativa entre laprecipitación en el Oeste de la región de estudio (clima tipo Mediterráneo) durante laprimavera, el verano y el otoño y la Oscilación Antártica (AAO). El fenómeno El Niño-Oscilación del Sur (ENOS) está relacionado, en su fase cálida, a un aumento deprecipitación sobre la Cordillera de los Andes, particularmente al Oeste de esta durante laprimavera. En el invierno, los eventos cálidos ENOS están asociados a mayoresprecipitaciones en el sector Este de la región. Los índices del Océano Atlántico (SAODI yTSA) solo muestran una relación negativa con la precipitación en el Este de la regióndurante el invierno. La AAO resulta ser el principal forzante de las variaciones en latemperatura en el norte de la Patagonia. Muestra relaciones positivas con esta variable en elSur de la región durante el verano, el otoño y la primavera; y en el Este de la región duranteel invierno.En el capítulo 4 se analiza la variabilidad espacial y temporal del Índice de VegetaciónNormalizado (IVN) mediante el análisis de componentes principales, y se comparan lasregiones que resultan de este análisis con clasificaciones previas de la vegetación en laregión que tienen en cuenta atributos estructurales o funcionales de la misma. Lavariabilidad espacio-temporal del IVN derivado de sensores remotos fue analizada tanto anivel de Región Ecológica Homogénea o Tipo Forestal , como a escala regional aplicandoel Análisis de Componentes Principales (ACP). La variabilidad temporal se analizó a nivelintra-anual e interanual, filtrando el ciclo anual mediante el cálculo de los desvíosestandarizados. Se pudieron reconocer, a grandes rasgos, cuatro regiones donde lavariabilidad temporal del IVN se comporta de manera relativamente homogénea: 1) Regiónde Clima Mediterráneo, que se corresponde con los Tipos Forestales Araucaria, Coihue ?Raulí ? Roble, las Regiones Ecológicas de Pastizales Subandinos y de Sierras y Mesetas(en transición con el clima Frio Semiárido), y el Tipo Forestal Lenga, en transición con elclima Templado Oceánico; 2) Región de clima Semiárido Frío y Árido Frío, quecomprende a las Regiones Ecológicas de Sierras y Mesetas, Distrito central de Chubut yDistrito del Golfo (que a su vez conforman la Provincia Fitogeográfica Patagónica); 3) Región de climas Templado Oceánico y Subpolar Oceánico, que comprende a los TiposForestales Alerce, Siempreverde Valdiviano y Lenga adyacentes; 4) Región de Clima Friosemiárido, representada principalmente por la Provincia Fitogeográfica del Monte (MonteAustral y Monte Oriental). A grandes rasgos, se puede observar que el ciclo anual es elrasgo predominante de la variabilidad del IVN hacia el Noroeste de la región (zona declima mediterráneo). El ciclo anual pierde su amplitud hacia el Sur y hacia el Este, amedida que adquieren mayor importancia los ciclos intra- e inter-anuales.En el capítulo 5 se analiza la relación entre la variabilidad en el IVN y las variaciones en lasprecipitaciones y la temperatura, considerando diferentes escalas temporales en las que sepueden manifestar estas relaciones. La temperatura, particularmente al comienzo de laestación de crecimiento, parece ser el factor climático determinante del crecimiento de losBosques Templados y de algunas regiones ecológicas pertenecientes a la ProvinciaFitogeográfica de la Patagonia (Distritos del Golfo y Central de Chubut). Para la regiónecológica del Monte Oriental, la precipitación de verano es el factor determinante de ladinámica del IVN a escala intra-anual. Este acoplamiento entre la precipitación y el IVN enesta región no ha sido reportado en trabajos anteriores. Esta relación pareciera estarasociada a la mayor abundancia relativa de especies C4 en esta región. Las especies C4 sonparticularmente eficientes para aprovechar los eventos esporádicos de lluvia durante elverano. Este acoplamiento entre el IVN y la precipitación es evidente a diferentesfrecuencias temporales, particularmente en la escala interanual.En el capítulo 6 se abordó el estudio de la relación entre la variabilidad del IVN y lasvariaciones climáticas de gran escala. Los índices muestran diferentes asociaciones con lospatrones de IVN según la región y la época del año. En líneas generales, la AAO influenciatodos los patrones de IVN. Esto probablemente se deba a que su influencia en laprecipitación y la temperatura abarcan casi la totalidad de la región estudiada. El fenómenoEl Niño-Oscilación del Sur también muestra asociaciones con tres patrones, pero surelación más notoria con el IVN se observa en los Bosques Siempreverde y de Alercedurante la primavera y el verano. Por su parte, tanto los índices asociados a la circulacióndel Océano Atlántico, así como las TSM del Atlántico tropical, influyen las variaciones en los patrones que corresponden a las Regiones Ecológicas del Monte Austral y MonteOriental y la Provincia Fitogeográfica de la Patagonia.This doctoral dissertation is organized in seven chapters. Chapter 1 provides the theoretical framework and the main goals of this thesis. In Chapter 2, 218 and 114 precipitation and temperature records, respectively, were compiled from different governmental and private institutions to develop a gridded climatic data base across northern Patagonia. Based on a co-kriging methodology, these precipitation and temperature records were interpolated into 20 x 20 km-resolution grids covering northern Patagonia from 63º to 75º W longitude (from Atlantic to Pacific coast) and from 35º to 45º S latitude. These new grids (Northern Patagonia Climate Grids, NPCG) represent spatial variations of both temperature and precipitation fields in a more realistic manner than other global climate grids currently available for the region. The performance of NPCG was contrasted with other global climate grids commonly used in northern Patagonia. This work has already been published in an international, indexed journal (DOI: 10.1007/s13351-015-5058-y). In Chapter 3, spatial and temporal variations in temperature and precipitation, based on NPCG (chapter 2) were analyzed, along with their relationships with large-scale climate forcings. The dominant modes of spatial and temporal variability in temperature and precipitation were determined by applying a Principal Component Analysis (PCA) to the gridded data sets. Once that the main patterns of temperature and precipitation variability were identified, they were compared with large-scale (continental, hemispheric to global) climatic drivers. Overall, the PCA analyses of the temperature and precipitation grids identified four different patterns of spatio-temporal variability in northern Patagonia. The northwestern Patagonia pattern shows the classical features related to the Mediterranean climate across Central Chile and the adjacent Cordillera de los Andes. The pattern associated with the cold semiarid climate prevails in the eastern and northeastern sectors of northern Patagonia. The spatial pattern related to the south-southeastern region in northern Patagonia encompass the dominant cold arid climate, whereas the southern and southwestern sectors in the study region coincides with the Pacific oceanic climate. The dominant patterns of variability in temperature and precipitation showed interesting links with several atmosphere/ocean circulation indexes. For example, negative relationships were recorded between precipitation in the Mediterranean sector during spring, summer and fall and the Antarctic Oscillation index (AAO). In contrast, the warm events of El Niño/Southern Oscillation (ENSO) are associated with positive rainfall anomalies west of the Andes range during spring. In winter, warm ENSO events are related to above-mean rainfalls anomalies in the Eastern sector of the study area. The indices associated with the tropical and subtropical Atlantic Ocean (SAODI and TSA) are negatively related to precipitation in the Eastern sector during winter. The AAO seems to be the main driver of temperature variability in northern Patagonia. The AAO shows positive relationships with temperature in the southern sector of northern Patagonia during summer, autumn and spring, and in the eastern sector during winter. The establishment of the spatio-temporal variations in the Normalized-Difference Vegetation Index (NDVI), based on Principal Component Analysis, was the main goal of Chapter 4. The NDVI-based regions identified were compared with vegetation classifications based on structural or functional features of vegetation across northern Patagonia. The spatio-temporal variability in NDVI was estimated based on previously established ecosystems (from forests to dry steppe) and similarities in NDVI according to PCA analysis). Temporal variations were analyzed in both intra and inter-annual scales. The annual cycle in NDVI was removed from the original time series by computing the standard deviations in relations to the period 2001-2010. Four regions with relativehomogeneous temporal behaviors were identified: 1) The Mediterranean climate region, which shows similarities with the Coihue – Rauli – Roble, Lenga and Araucaria forest types, and the Pastizales Subandinos and Sierras y Mesetas grassland-upper steppe types; 2) The region with cold semiarid and arid climate, which spatially overlaps with the Sierras y Mesetas, Distrito Central de Chubut and Distrito del Golfo steppe regions; 3) The region of temperate and subantartic oceanic climates, which is associated with the Alerce, Siempreverde Valdiviano and Lenga forest types; and 4) The region of cold semiarid climate related to the Monte Austral and Monte Oriental ecological regions. Overall, a dominant annual cycle is the main feature of the temporal evolution of the NDVI in the Mediterranean climate zone. The amplitude of the annual cycle diminishes towards the south and the east where intra- and inter-annual cycles gain importance. In Chapter 5, the relationships between the variability of NDVI and temperature and precipitation are documented, taking into consideration the different temporal scales in which interactions between these variables occur. Temperature, mainly at the beginning of the growing season, seems to be the determinant factor for the growth of the temperate forests and the Distritos del Golfo and Central de Chubut grassland-steppe regions. For the Monte Oriental ecological region, summer rainfall is the most important factor related to the inter-annual dynamic in the NDVI. This strong temporal coupling between summer rainfall and NDVI in the Monte oriental has not been previously reported. This relationship seems to be associated with the abundance of C4 species in this ecological region. C4 species take advantages of the sporadic summer rainfalls more efficiently than C3 plants. This coupling between rainfall and NDVI is present at different timescales, particularly at the inter-annual scale. Relationships between NDVI variability and large-scale climate forcings were documented in Chapter 6. Linkages between NDVI and large-scale atmospheric circulation indices vary according to the seasons and different vegetation regions across northern Patagonia. Overall, the AAO influences most patterns of NDVI variability, in response to the pervasive influences of the AAO on temperature and precipitation regimens over most northern Patagonia. ENSO shows linkages with the Siempreverde Valdiviano and Alerce forest types during spring and summer. Finally, the indices associated with variations in the circulation of the Atlantic Ocean and Sea Surface Temperatures (SST) across the tropical Atlantic Ocean are related to NDVI patterns in the Monte Austral and Monte Oriental ecological regions. Finally, Chapter 7 discuss the results and provides directions for further research.Fil: Bianchi, Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentin

Several Nuclear Events during Apoptosis Depend on Caspase-3 Activation but Do Not Constitute a Common Pathway

A number of nuclear events occur during apoptosis, including DNA laddering, nuclear lamina breakdown, phosphorylation of histones H2B and histone H2AX, and the tight binding to chromatin of HMGB1 and CAD, the nuclease responsible for DNA laddering. We have performed an epistasis analysis to investigate whether these events cluster together in pathways. We find that all depend directly or indirectly on caspase-3 activation. CAD activation, H2AX phosphorylation and DNA laddering cluster together into a pathway, but all other events appear to be independent of each other downstream of caspase-3, and likely evolved subject to different functional pressures

Cathodoluminescence from beta-Ga_2O_3 nanowires

ß-Ga_2O_3 nano- and microwires with diameters ranging from tens of nanometers to about one micron and lengths of up to tens of microns, have been obtained by sintering Ga_2O_3 powder under argon flow. The structures have been investigated by cathodoluminescence in the scanning electron microscope. The samples showed the violet-blue emission characteristic of Ga_2O_3 and a red emission at 1.73 eV dominant in the nanowires and other nano- and microstructures formed during the sintering treatment. At temperatures below 210 K, this band exhibits sharp peaks separated by 20 meV. This observation suggests the exchange of phonons in the recombination process

Influence of Li doping on the morphology and luminescence of Ga_2O_3 microrods grown by a vapor-solid method

Gallium oxide microrods have been grown by an evaporation-deposition method by using a precursor containing lithium in order to check the influence of such dopant on the morphology and physical properties of the obtained ß-Ga_2O_3 structures. SEM studies show that the morphology is modified with respect to undoped gallium oxide, promoting the growth of micropyramids transversal to the microwire axis. Raman analysis reveals good crystal quality and an additional Raman peak centred at around 270 cm^(-1), characteristic of these samples and not present in undoped monoclinic gallium oxide. The presence of the Li^(+) ions also influences the luminescence emission by inducing a red-shift of the characteristic UV-blue defect band of gallium oxide. In addition, an intense sharp peak centred around 717 nm observed both by cathodoluminescence (CL) and photoluminescence (PL) is also attributed to the presence of these ions. The Li related luminescence features have also been investigated by PL excitation (PLE) spectra and by the temperature dependence of the luminescence

Shape engineering driven by selective growth of SnO2 on doped Ga2O3 nanowires

Tailoring the shape of complex nanostructures requires control of the growth process. In this work, we report on the selective growth of nanostructured tin oxide on gallium oxide nanowires leading to the formation of SnO2/Ga2O3 complex nanostructures. Ga2O3 nanowires decorated with either crossing SnO2 nanowires or SnO2 particles have been obtained in a single step treatment, by thermal evaporation. The reason for this dual behavior is related to the growth direction of trunk Ga2O3 nanowires. Ga2O3 nanowires grown along the [001] direction favor the formation of crossing SnO2 nanowires. Alternatively, SnO2 forms rhombohedral particles on [110] Ga2O3 nanowires leading to skewer-like structures. These complex oxide structures were grown by a catalyst-free vapor-solid process. When pure Ga and tin oxide were used as source materials and compacted powders of Ga2O3 acted as substrates, [110] Ga2O3 nanowires grow preferentially. High-resolution transmission electron microscopy analysis reveals epitaxial relationship lattice matching between the Ga2O3 axis and SnO2 particles, forming skewer-like structures. The addition of chromium oxide to the source materials modifies the growth direction of the trunk Ga2O3 nanowires, growing along the [001], with crossing SnO2 wires. The SnO2/Ga2O3 junctions does not meet the lattice matching condition, forming a grain boundary. The electronic and optical properties have been studied by XPS and CL with high spatial resolution, enabling us to get both local chemical and electronic information of the surface in both type of structures. The results will allow tuning optical and electronic properties of oxide complex nanostructures locally as a function of the orientation. In particular, we report a dependence of the visible CL emission of SnO2 on its particular shape. Orange emission dominates in SnO2/Ga2O3 crossing wires while green-blue emission is observed in SnO2 particles attached to Ga2O3 trunks. The results show that the Ga2O3-SnO2 system appears to be a benchmark for shape engineering to get architectures involving nanowires via the control of the growth direction of the nanowires

Timing chirurgico nell’adenoma epatico sanguinante: case report

La diagnosi di adenoma epatico, la cui eziopatogenesi è spesso un rapporto con l’assunzione prolungata di estroprogestinici (il 90% degli adenomi si osserva in donne che hanno preso la ‘pillola’ per più di 5 anni), impone sempre una indicazione chirurgica resettiva. La ragione è data dalle caratteristiche peculiari della neoplasia, che sono la degenerazione maligna (4%) e l’elevato rischio di sanguinamento (30- 50%), intratumorale e/o intraaddominale, che aumenta in gravidanza e in puerperio. La regressione dopo sospensione della terapia ormonale, infatti, è poco frequente e non elimina il rischio di degenerazione e/o emorragia. La resezione epatica dovrebbe essere condotta in combinazione con appropriate procedure di embolizzazione endovascolare selettiva, considerato che la chirurgia in emergenza potrebbe imporre un sacrificio epatico maggiore, esponendo il paziente a morbilità e mortalità più elevate. I tempi di attesa dall’embolizzazione all’intervento elettivo non sono standardizzati e sono pertanto indicati dall’esperienza personale e soprattutto da un attento e seriato follow-up del paziente. Gli Autori riportano la propria esperienza nella strategia terapeutica e nel timing chirurgico di un caso di adenoma epatico sanguinante

β-Ga₂O₃ nanowires for an ultraviolet light selective frequency photodetector

The behaviour of ß-Ga₂O₃ nanowires as photoconductive material in deep ultraviolet photodetectors to operate in the energy range 3.0-6.2 eV has been investigated. The nanowires were grown by a catalyst-free thermal evaporation method on gallium oxide substrates. Photocurrent measurements have been carried out on both undoped and Sn-doped Ga₂O₃ nanowires to evidence the influence of the dopant on the photodetector performances. The responsivity spectrum of single nanowires show maxima in the energy range 4.8-5.4 eV and a strong dependence on the pulse frequency of the excitation light has been observed for undoped nanowires. Our results show that the responsivity of beta- Ga₂O₃ nanowires can be controlled by tuning the chopper frequency of the excitation light and/ or by doping of the nanowires. Non-linear behavior in characteristic current-voltage curves has been observed for Ga₂O₃ : Sn nanowires. The mechanism leading to this behaviour has been discussed and related to space-charged-limited current effects. In addition, the responsivity achieved by doped nanowires at lower bias is higher than for undoped ones

Coping with the COVID-19 pandemic: the technical, moral and facilitating role of management control

Purpose – The study analyses how management control supports the organisation's response to the COVID-19 pandemic lockdown.Design/methodology/approach – Video interviews with top and middle-level managers who were directly involved in handling the response to the COVID-19 crisis in late winter and spring 2020 form the empirical base. The object-of-control framework and the distinction between organic and mechanistic management controls inform the exploratory case analysis of a large food retail cooperative in Italy.Findings – Both organic and mechanistic management control mechanisms enabled an immediate response and management of the crisis. The use of cultural, action and results controls supported employees' health and safety coordination, a tight monitoring of financial performance and social interventions in support of the local community. Originality/value – The study provides original exploratory insights on the use and role of management control in the context of an unprecedented emergency and an unplanned setting (i.e. a pandemic crisis), which is an under-investigated topic in the accounting literature. The study shows how management control operated, linking moral and technical aspects as well as facilitating organisational adaptation and pandemic effects mitigation