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El meu treball de final de grau pretén estudiar i donar a conèixer tots els passos a seguir per poder portar a terme un projecte mecànic, i concretament, en aquest cas, una polidora de banda, des del moment que una persona té la idea fins a la fabricació de l’objecte en qüestió, amb la finalitat de poder servir de referent per a qualsevol persona interessada en la construcció d’una màquina. S’ha de tenir en compte no només el disseny sinó també els costos, tant d’ investigació, com de disseny, de gestió, dels materials, de fabricació i de muntatge, i veure si és viable econòmicament, tenint en compte els processos de fabricació, materials i tractaments, sense anar en detriment de la qualitat de les peces. Després d’un procés d’investigació del que existeix al mercat relacionat amb la nostra idea, començarem a dibuixar la màquina, els seus mecanismes...per passar a continuació amb el disseny 3D, pas previ a la realització dels plànols amb la informació de cada peça. També haurem d’anar fent càlculs tant estructurals com del cost econòmic que implicarà. A partir d’aquí es procedirà a la gestió per a la compra del material més adient tenint en compte la relació qualitat-preu, i ja es podrà començar la fabricació i ensamblatge de les diferents peces de la màquina., My end of degree thesis aims at studying and publishing all the steps to be taken into account to carry out a mechanical project, in this case, a belt grinder, from the moment the person gets the idea to the manufacturing of the machine. My project can be used as a reference by anybody interested in this procedure. Not only the design must be considered but also the costs of research, design, management, materials, assembly and it must be analyzed if it is economically viable, taking into account the manufacturing processes, materials, and the treatments, without compromising the quality of the pieces. After a market research process related to our idea, we’ll start by drawing the machine, its mechanisms, to carry on with the 3D design, step to be taken before the making of the drawings of the different pieces. The economical cost must also be considered, and then the material will be purchased after choosing the best offer from the suppliers, taking into account the relationship between quality and price. After that the manufacturing and assembling of the different pieces can be carried out.

We analyzed the impacts of drought severity on a variety of sectors in a topographically complex basin (the upper Aragón basin 2181 km2) in the Central Spanish Pyrenees. Using diverse data sources including meteorological and hydrological observations, remote sensing and tree rings, we analyze the possible hydrological implications of drought occurrence and severity on water availability in various sectors, including downstream impacts on irrigation water supply for crop production. Results suggest varying responses in forest activity, secondary growth, plant phenology, and crop yield to drought impacts. Specifically, meteorological droughts have distinct impacts downstream, mainly due to water partitioning between streamflow and irrigation channels that transport water to crop producing areas. This implies that drought severity can extend beyond the physical boundaries of the basin, with impacts on crop productivity. This complex response to drought impacts makes it difficult to develop objective basin-scale operational definitions for monitoring drought severity. Moreover, given the high spatial variability in responses to drought across sectors, it is difficult to establish reliable drought thresholds from indices that are relevant across all socio-economic sectors. The anthropogenic impacts (e.g. water regulation projects, ecosystem services, land cover and land use changes) pose further challenges to assessing the response of different systems to drought severity. This study stresses the need to consider the seasonality of drought impacts and appropriate drought time scales to adequately assess and understand their complexity

The dynamics of blue and green water partitioning under vegetation and climate change, as well as their different interactions during wet and dry periods, are poorly understood in the literature. We analyzed the impact of vegetation changes on blue water generation in a central Spanish Pyrenees basin undergoing intense afforestation. We found that vegetation change is a key driver of large decreases in blue water availability. The effect of vegetation increase is amplified during dry years, and mainly during the dry season, with streamflow reductions of more than 50%. This pattern can be attributed primarily to increased plant water consumption. Our findings highlight the importance of vegetation changes in reinforcing the decrease in water resource availability. With aridity expected to rise in southern Europe over the next few decades, interactions between climate and land management practices appear to be amplifying future hydrological drought risk in the region.

We present a long-term assessment of precipitation trends in Southwestern Europe (1850–2018) using data from multiple sources, including observations, gridded datasets and global climate model experiments. Contrary to previous investigations based on shorter records, we demonstrate, using new long-term, quality controlled precipitation series, the lack of statistically significant long-term decreasing trends in precipitation for the region. Rather, significant trends were mostly found for shorter periods, highlighting the prevalence of interdecadal and interannual variability at these time-scales. Global climate model outputs from three CMIP experiments are evaluated for periods concurrent with observations. Both the CMIP3 and CMIP5 ensembles show precipitation decline, with only CMIP6 showing agreement with long term trends in observations. However, for both CMIP3 and CMIP5 large interannual and internal variability among ensemble members makes it difficult to identify a trend that is statistically different from observations. Across both observations and models, our results make it difficult to associate any declining trends in precipitation in Southwestern Europe to anthropogenic forcing at this stage.

© 2020, The Author(s). Monitoring and management of several environmental and socioeconomic sectors require climate data that can be summarized using a set of standard and meaningful climate metrics. This study describes a newly developed gridded dataset for the whole of Europe, which employed a set of 125 climate indices spanning different periods based on data availability, but mainly 1950–2017 and 1979–2017. This dataset comprehensively summarizes climate variability in Europe for a wide range of climate variables and conditions, including air temperature, precipitation, biometeorology, aridity, continentality, drought, amongst others. Climate indices were computed at different temporal scales (i.e. monthly, seasonal and annual) and mapped at a grid interval of 0.25°. We intend to update these indices on an annual basis. This dataset is freely available to research and end-user communities.

Una vegada el Virus de la Immunodeficiència Humana tipus 1 (en anglès HIV-1) infecta l'organisme hoste es produeix una ràpida i severa destrucció del teixit limfoide associat a tracte gastrointestinal que inclou, entre d'altres, significants pèrdues cel·lulars del sistema immunitari i epitelial de l'hoste. Seguidament es produeix un increment de la permeabilitat de la paret intestinal que permet la translocació microbiana. Així i doncs, productes i cèl·lules microbianes que normalment queden confinats i controlats dins la llum intestinal ara poden travessar l'epiteli intestinal i entrar en circulació sanguínia convertint-se en un nou focus d'activació immunitària i inflamació. Per la seva significant contribució en la patogènesis del HIV-1, gran part de la recerca en microbioma dels últims anys s'ha centrat en entendre els canvis que tenen lloc en les comunitats microbianes que habiten dins l'intestí humà després de la infecció per HIV-1 i de l'inici de tractament antiretroviral (en anglès ART). Els primers estudis transversals van descriure relacions contradictòries entre la riquesa i diversitat microbiana a l'intestí i la infecció per HIV-1 i van suggerir una substitució de Bacteroides per Prevotella com a conseqüència de l'adquisició viral. Aquests resultats però, no s'han confirmat ni en models animals ni en estudis balancejats per grups de risc de transmissió de VIH-1. En estudis en models de primats no humans la infecció pel virus de la immunodeficiància de simi s'ha associat a una expansió de les comunitats víriques intestinals però no s'ha descrit un canvi consistent en les comunitats bacterianes. En dues cohorts europees independents de persones amb infecció crònica per HIV-1 i persones no infectades de Barcelona (n=156) i Estocolm (n=84), els individus homosexuals (en anglès MSM), presentaven una microbiota intestinal més rica i diversa i una major abundància relativa de Prevotella, en comparació amb individus heterosexuals (no-MSM) que estaven enriquits p, Soon after Human Immunodeficiency Virus type 1 (HIV-1) infection, a severe and rapid depletion of the gut-associated lymphoid tissue occurs, including significant loss of both, immune and epithelial host cells. This is followed by an increased permeability of the intestinal cell lining which facilitates microbial translocation. Microbial cells and products that are usually contained and controlled within the intestinal lumen, can now circulate in the bloodstream and become a new source for immune activation and inflammation. Because of the significant immune imbalance in the GALT after HIV-1 infection, recent microbiome research has focused on understanding the changes occurring in the microbial communities inhabiting the human gut after HIV-1 perturbation and in response to antiretroviral treatment (ART). Initial cross-sectional studies provided contradictory associations between gut microbial richness and diversity and HIV-1 infection and suggested shifts from Bacteroides to Prevotella predominance following viral infection. Nonetheless, these results have not been confirmed in animal models or in studies matched for HIV-1 transmission risk groups. For instance, in non-human primate models Simian Immunodeficiency Virus infection is followed by expansion of enteric virome but has a limited impact on the gut bacteriome. In two independent European cross-sectionals cohorts of chronically HIV-1-infected subjects and uninfected controls, in Barcelona (n=156) and Stockholm (n=84), men-who-have-sex-with-men (MSM) showed a Prevotella-enriched gut microbiota and higher microbial richness and diversity compared to non-MSM individuals who predominantly showed a Bacteroides-enriched microbiota, regardless of HIV-1 infection. After stratifying for sexual orientation (MSM vs. non-MSM), we described lower microbial richness and diversity in HIV-1 infected subjects, more so in subjects with an immune-discordant response to ART, but there was no solid evidence of an HIV-1-specific

Attribution of trends in streamflow is complex, but essential, in identifying optimal management options for water resources. Disagreement remains on the relative role of climate change and human factors, including water abstractions and land cover change, in driving change in annual streamflow. We construct a very dense network of gauging stations (n = 1,874) from Ireland, the United Kingdom, France, Spain, and Portugal for the period of 1961–2012 to detect and then attribute changes in annual streamflow. Using regression‐based techniques, we show that climate (precipitation and atmospheric evaporative demand) explains many of the observed trends in northwest Europe, while for southwest Europe human disturbances better explain both temporal and spatial trends. For the latter, large increases in irrigated areas, agricultural intensification, and natural revegetation of marginal lands are inferred to be the dominant drivers of decreases in streamflow.

Attribution of trends in streamflow is complex, but essential, in identifying optimal management options for water resources. Disagreement remains on the relative role of climate change and human factors, including water abstractions and land cover change, in driving change in annual streamflow. We construct a very dense network of gauging stations (n = 1,874) from Ireland, the United Kingdom, France, Spain, and Portugal for the period of 1961–2012 to detect and then attribute changes in annual streamflow. Using regression‐based techniques, we show that climate (precipitation and atmospheric evaporative demand) explains many of the observed trends in northwest Europe, while for southwest Europe human disturbances better explain both temporal and spatial trends. For the latter, large increases in irrigated areas, agricultural intensification, and natural revegetation of marginal lands are inferred to be the dominant drivers of decreases in streamflow.