Hölder's inequality: some recent and unexpected applications

Holder's inequality, since its appearance in 1888, has played a fundamental role in Mathematical Analysis and may be considered a milestone in Mathematics. It may seem strange that, nowadays, it keeps resurfacing and bringing new insights to the mathematical community. In this survey we show how a variant of Holder's inequality (although well-known in PDEs) was essentially overlooked in Functional/Complex Analysis and has had a crucial (and in some sense unexpected) influence in very recent advances in different fields of Mathematics. Some of these recent advances have been appearing since 2012 and include the theory of Dirichlet series, the famous Bohr radius problem, certain classical inequalities (such as Bohnenblust-Hille or Hardy-Littlewood), and Mathematical Physics

Using discrete Ricci curvatures to infer COVID-19 epidemic network fragility and systemic risk

The damage of the novel Coronavirus disease (COVID-19) is reaching unprecedented scales. There are numerous classical epidemiology models trying to quantify epidemiology metrics. Usually, to forecast epidemics, classical approaches need parameter estimations, such as the contagion rate or the basic reproduction number. Here, we propose a data-driven, parameter-free, geometric approach to access the emergence of a pandemic state by studying the Forman-Ricci and Ollivier- Ricci network curvatures. Discrete Ollivier-Ricci curvature has been used successfully to forecast risk in nancial networks and we suggest that those results can provide analogous results for COVID-19 epidemic time-series. We rst compute both curvatures in a toy-model of epidemic time-series with delays, which allows us to create epidemic networks. We also compared our results to classical network metrics. By doing so, we are able to verify that the Ollivier-Ricci and Forman-Ricci curvatures can be a parameter-free estimate for identifying a pandemic state in the simulated epidemic. On this basis, we then compute both Forman-Ricci and Ollivier-Ricci curvatures for real epidemic networks built from COVID-19 epidemic time-series available at the World Health Organization (WHO). This approach allow us to detect early warning signs of the emergence of the pandemic. The advantage of our method lies in providing an early geometrical data marker for the pandemic state, regardless of parameter estimation and stochastic modelling. This work opens the possibility of using discrete geometry to study epidemic networks. Keywords: COVID-19, SARS2, Forman-Ricci Curvature, Ollivier-Ricci curvature, Epidemiology, Topologi- cal Data Analysi

Identification of coherent flood regions across Europe by using the longest streamflow records

This study compiles a new dataset, consisting of the longest available flow series from across Europe, and uses it to study the spatial and temporal clustering of flood events across the continent. Hydrological series at 102 gauging stations were collected from 25 European countries. Five geographically distinct large-scale homogeneous regions are identified: (i) an Atlantic region, (ii) a Continental region, (iii) a Scandinavian region, (iv) an Alpine region, and (v) a Mediterranean region. The months with a higher likelihood of flooding were identified in each region. The analysis of the clustering of annual counts of floods revealed an over-dispersion in the Atlantic and Continental regions, forming flood-rich and flood-poor periods, as well as an under-dispersion in the Scandinavian region that points to a regular pattern of flood occurrences at the inter-annual scale. The detection of trends in flood series is attempted by basing it on the identified regions, interpreting the results at a regional scale and for various time periods: 1900-1999; 1920-1999; 1939-1998 and 1956-1995. The results indicate that a decreasing trend in the magnitude of floods was observed mainly in the Continental region in the period 1920-1999 with 22% of the catchments revealing such a trend, as well as a decreasing trend in the timing of floods in the Alpine region in the period 1900-1999 with 75% of the catchments revealing this trend. A mixed pattern of changes in the frequency of floods over a threshold and few significant changes in the timing of floods were detected

Plan de formación y docencia en un centro integral de cáncer: estrategia e implementación

Introducción: El Institut Català d'Oncologia (ICO) puso en marcha la Unidad de Formación y Docencia (UFiD), en el año 2006, con el objetivo de potenciar el desarrollo profesional, la difusión del conocimiento y la calidad de la atención oncológica. En el presente artículo se describe el proceso de puesta en marcha de la UFiD, los resultados del estudio de las necesidades formativas realizada por los profesionales y colectivos de la institución, las acciones formativas organizadas, y en el área de docencia, los resultados de la reorganización de las trayectorias docentes de los diferentes servicios, así como el apoyo de nuevas iniciativas. Materiales y métodos: Durante el periodo 2008-2009, se implantaron acciones formativas y docentes en concordancia con los resultados del estudio de necesidades y con las líneas estratégicas de la institución. Se realizaron un total de 71 actividades formativas, con 898 participantes de todas las categorías profesionales, con una tasa de satisfacción de los participantes de 7,8 sobre 10. En el apartado de docencia, durante el mismo periodo se realizaron 3 másteres, 3 posgrados, 59 cursos de actualización con metodología semipresencial y 19 cursos con metodología online, todos ellos con acreditación académica. La satisfacción media fue de 8 sobre 10. Resultados y conclusiones: La actividad llevada a cabo por la UFiD ha permitido, por una parte, articular la formación continuada en base al estudio de las necesidades de los profesionales, lo que ha contribuido a promover el desarrollo profesional y la calidad asistencial de éstos, y por otra parte, dar soporte a las actividades docentes ya existentes y promover nuevas iniciativas para favorecer la difusión de conocimientos en el área oncológica, lo que ha posicionado al ICO como un centro absolutamente comprometido con la formación oncológica

Genome-wide profiling of non-smoking-related lung cancer cells reveals common RB1 rearrangements associated with histopathologic transformation in EGFR-mutant tumors.

The etiology and the molecular basis of lung adenocarcinomas (LuADs) in nonsmokers are currently unknown. Furthermore, the scarcity of available primary cultures continues to hamper our biological understanding of non-smoking-related lung adenocarcinomas (NSK-LuADs). We established patient-derived cancer cell (PDC) cultures from metastatic NSK-LuADs, including two pairs of matched EGFR-mutant PDCs before and after resistance to tyrosine kinase inhibitors (TKIs), and then performed whole-exome and RNA sequencing to delineate their genomic architecture. For validation, we analyzed independent cohorts of primary LuADs. In addition to known non-smoker-associated alterations (e.g. RET, ALK, EGFR, and ERBB2), we discovered novel fusions and recurrently mutated genes, including ATF7IP, a regulator of gene expression, that was inactivated in 5% of primary LuAD cases. We also found germline mutations at dominant familiar-cancer genes, highlighting the importance of genetic predisposition in the origin of a subset of NSK-LuADs. Furthermore, there was an over-representation of inactivating alterations at RB1, mostly through complex intragenic rearrangements, in treatment-naive EGFR-mutant LuADs. Three EGFR-mutant and one EGFR-wild-type tumors acquired resistance to EGFR-TKIs and chemotherapy, respectively, and histology on re-biopsies revealed the development of small-cell lung cancer/squamous cell carcinoma (SCLC/LuSCC) transformation. These features were consistent with RB1 inactivation and acquired EGFR-T790M mutation or FGFR3-TACC3 fusion in EGFR-mutant tumors. We found recurrent alterations in LuADs that deserve further exploration. Our work also demonstrates that a subset of NSK-LuADs arises within cancer-predisposition syndromes. The preferential occurrence of RB1 inactivation, via complex rearrangements, found in EGFR-mutant tumors appears to favor SCLC/LuSCC transformation under growth-inhibition pressures. Thus RB1 inactivation may predict the risk of LuAD transformation to a more aggressive type of lung cancer, and may need to be considered as a part of the clinical management of NSK-LuADs patients.This work was supported by the Fundacion Cientifica Asociacion Española Contra el Cancer-AECC (grant number GCB14142170MONT) to LMM, MS-C, and EF; the Spanish Ministry of Economy and Competitivity-MINECO (grant number SAF-2017-82186R to MS-C; Rio Hortega-CM17/00180 to MS; PROYBAR17005NADA to EN); the Health Institute Carlos III-ISCIII, Fondo Europeo de Desarrollo Regional-FEDER (grant Number PT13/0001/0044, PT17/0009/0019, PI16 01821); the Government of Navarra (grant number DIANA project); and the Ramon Areces Foundation (no grant number is applicable) to LMM and RP.S

A global analysis of the comparability of winter chill models for fruit and nut trees

Many fruit and nut trees must fulfill a chilling requirement to break their winter dormancy and resume normal growth in spring. Several models exist for quantifying winter chill, and growers and researchers often tacitly assume that the choice of model is not important and estimates of species chilling requirements are valid across growing regions. To test this assumption, Safe Winter Chill (the amount of winter chill that is exceeded in 90% of years) was calculated for 5,078 weather stations around the world, using the Dynamic Model [in Chill Portions (CP)], the Chilling Hours (CH) Model and the Utah Model [Utah Chill Units (UCU)]. Distributions of the ratios between different winter chill metrics were mapped on a global scale. These ratios should be constant if the models were strictly proportional. Ratios between winter chill metrics varied substantially, with the CH/CP ratio ranging between 0 and 34, the UCU/CP ratio between −155 and +20 and the UCU/CH ratio between −10 and +5. The models are thus not proportional, and chilling requirements determined in a given location may not be valid elsewhere. The Utah Model produced negative winter chill totals in many Subtropical regions, where it does not seem to be useful. Mean annual temperature and daily temperature range influenced all winter chill ratios, but explained only between 12 and 27% of the variation. Data on chilling requirements should always be amended with information on the location and experimental conditions of the study in which they were determined, ideally including site-specific conversion factors between winter chill models. This would greatly facilitate the transfer of such information across growing regions, and help prepare growers for the impact of climate change

Reproductive biology traits affecting productivity of sour cherry

The objective of this work was to evaluate variability in reproductive biology traits and the correlation between them in genotypes of 'Oblacinska' sour cherry (Prunus cerasus). High genetic diversity was found in the 41 evaluated genotypes, and significant differences were observed among them for all studied traits: flowering time, pollen germination, number of fruiting branches, production of flower and fruit, number of flowers per bud, fruit set, and limb yield efficiency. The number of fruiting branches significantly influenced the number of flower and fruit, fruit set, and yield efficiency. In addition to number of fruiting branches, yield efficiency was positively correlated with fruit set and production of flower and fruit. Results from principal component analysis suggested a reduction of the reproductive biology factors affecting yield to four main characters: number and structure of fruiting branches, flowering time, and pollen germination. Knowledge of the reproductive biology of the 'Oblacinska' genotypes can be used to select the appropriate ones to be grown or used as parents in breeding programs. In this sense, genotypes II/2, III/9, III/13, and III/14 have very good flower production and satisfactory pollen germination

Enhanced wheat yield by biochar addition under different mineral fertilization levels

Climate change and global warming have worldwide adverse consequences. Biochar production and its use in agriculture can play a key role in climate change mitigation and help improve the quality and management of waste materials coming from agriculture and forestry. Biochar is a carbonaceous material obtained from thermal decomposition of residual biomass at relatively low temperature and under oxygen limited conditions (pyrolysis). Biochar is currently a subject of active research worldwide because it can constitute a viable option for sustainable agriculture due to its potential as a long-term sink for carbon in soil and benefits for crops. However, to date, the results of research studies on biochar effects on crop production show great variability, depending on the biochar type and experimental conditions. Therefore, it is important to identify the beneficial aspects of biochar addition to soil on crop yield in order to promote the adoption of this practice in agriculture. In this study, the effects of two types of biochar from agricultural wastes typical of Southern Spain: wheat straw and olive tree pruning, combined with different mineral fertilization levels on the growth and yield of wheat (Triticum durum L. cv. Vitron) were evaluated. Durum wheat was pot-grown for 2 months in a growth chamber on a soil collected from an agricultural field near Córdoba, Southern Spain. Soil properties and plant growth variables were studied in order to assess the agronomic efficiency of biochar. Our results show that biochar addition to a nutrientpoor, slightly acidic loamy sand soil had little effect on wheat yield in the absence of mineral fertilization. However, at the highest mineral fertilizer rate, addition of biochar led to about 20–30 % increase in grain yield compared with the use of the mineral fertilizer alone. Both biochars acted as a source of available P, which led to beneficial effects on crop production. In contrast, the addition of biochar resulted in decreases in available N and Mn. A maximum reduction in plant nutrient concentration of 25 and 80% compared to nonbiochar-treated soils for N and Mn, respectively, was detected. This fact was related to the own nature of biochar: low available nitrogen content, high adsorption capacity, and low mineralization rate for N; and alkaline pH and high carbonate content for Mn. Our results indicate that biochar-based soil management strategies can enhance wheat production with the environmental benefits of global warming mitigation. This can contribute positively to the viability and benefits of agricultural production systems. However, the nutrient–biochar interactions should receive special attention due to the great variability in the properties of biochar-type materials

Silencing Agrobacterium oncogenes in transgenic grapevine results in strain-specific crown gall resistance

Crown gall disease of grapevine induced by Agrobacterium vitis or Agrobacterium tumefaciens causes serious economic losses in viticulture. To establish crown gall-resistant lines, somatic proembryos of Vitis berlandieri × V. rupestris cv. 'Richter 110' rootstock were transformed with an oncogene-silencing transgene based on iaaM and ipt oncogene sequences from octopine-type, tumor-inducing (Ti) plasmid pTiA6. Twentyone transgenic lines were selected, and their transgenic nature was confirmed by polymerase chain reaction (PCR). These lines were inoculated with two A. tumefaciens and three A. vitis strains. Eight lines showed resistance to octopine-type A. tumefaciens A348. Resistance correlated with the expression of the silencing genes. However, oncogene silencing was mostly sequence specific because these lines did not abolish tumorigenesis by A. vitis strains or nopaline-type A. tumefaciens C58