6,076 research outputs found

    The agrarian economy of the region of Évora in the first half of the 17th century (1595-1660): an exploration of main indicators

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    Este artículo intenta establecer la cronología y dinámica de la depresión del siglo XVII en la región de Évora, en el sur de Portugal. El examen de un conjunto de variables clave –estadísticas vitales, precios de alimentos y renta de la tierra– sitúa el inicio de la depresión en la última década del siglo XVI, así como su continuación hasta 1660. Se detectan varios intentos de recuperación, pero todos ellos cortados por malas cosechas, a veces asociadas con epidemias y guerra. En conjunto, las alzas de precios de los alimentos aparecen asociadas con signos de depresión en las demás variables. Esto parece indicar que esas alzas venían dictadas por el comportamiento de la oferta, no de la demanda, pesando gravemente sobre los ingresos de la mayor parte de las familias, mientras que los campesinos resultaban incapaces de aprovecharlas.This article tries to establish the chronology and dynamics of the 17th century economic depression in the region of Évora, in Southern Portugal. By examining a set of key variables –vital statistics, prices of foodstuffs and farm rents– the onset of the depression is located in the last decade of 16th century, and its continuation up to 1660 is attested. A number of attempts to recovery are detected, but all of them were checked by poor harvests, sometimes joined by plague and war. On the whole, high prices of foodstuffs appear to be associated with signals of depression in the behaviour of other variables. This seems to indicate that these price increases were supply-driven, rather than demand-driven, weighting heavily on the incomes of most families, whereas small farmers were unable to take advantage of these seemingly favourable conjunctures.Publicad

    Experimental signature of a fermiophobic Higgs boson

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    The most general Two Higgs Doublet Model potential without explicit CP violation depends on 10 real independent parameters . Excluding spontaneous CP violation results in two 7 parameter models. Although both models give rise to 5 scalar particles and 2 mixing angles, the resulting phenomenology of the scalar sectors is different. If flavour changing neutral currents at tree level are to be avoided, one has four alternative ways of introducing the fermion couplings in both cases. In one of these models the mixing angle of the CP even sector can be chosen in such a way that the fermion couplings to the lightest scalar Higgs boson vanishes. At the same time it is possible to suppress the fermion couplings to the charged and pseudo-scalar Higgs boson by appropriately choosing the mixing angle of the CP odd sector. We investigate the phenomenology of both models in the fermiophobic limit and present the different branching ratios for the decays of the scalar particles. We use the present experimental results from the LEP collider to constrain the models.Comment: Contribution to Proceedings of 9th Lomonosov Conferenc

    CO2 and nutrient-driven changes across multiple levels of organization in zostera noltii ecosystems

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    Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/ or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low-and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and context-dependent, being mediated by epiphyte overgrowth rather than by direct effects on plant biochemistry. Overall, we found that the responses of seagrass meadows to individual and interactive effects of CO2 and nutrient enrichment varied depending on interactions among species and connections between organization levels.European Regional Development Fund through the COMPETE; Portuguese funds through the FCT project [PEst-C/MAR/LA0015/2011]

    ScannerS: Constraining the phase diagram of a complex scalar singlet at the LHC

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    We present the first version of a new tool to scan the parameter space of generic scalar potentials, ScannerS. The main goal of ScannerS is to help distinguish between different patterns of symmetry breaking for each scalar potential. In this work we use it to investigate the possibility of excluding regions of the phase diagram of several versions of a complex singlet extension of the Standard Model, with future LHC results. We find that if another scalar is found, one can exclude a phase with a dark matter candidate in definite regions of the parameter space, while predicting whether a third scalar to be found must be lighter or heavier. The first version of the code is publicly available and contains various generic core routines for tree level vacuum stability analysis, as well as implementations of collider bounds, dark matter constraints, electroweak precision constraints and tree level unitarity.Comment: 24 pages, 4 figures, 3 tables. Project development webpage - http://gravitation.web.ua.pt/Scanner

    NLO electroweak corrections in general scalar singlet models

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    If no new physics signals are found, in the coming years, at the Large Hadron Collider Run-2, an increase in precision of the Higgs couplings measurements will shift the dicussion to the effects of higher order corrections. In Beyond the Standard Model (BSM) theories this may become the only tool to probe new physics. Extensions of the Standard Model (SM) with several scalar singlets may address several of its problems, namely to explain dark matter, the matter-antimatter asymmetry, or to improve the stability of the SM up to the Planck scale. In this work we propose a general framework to calculate one loop-corrections in BSM models with an arbitrary number of scalar singlets. We then apply our method to a real and to a complex scalar singlet models. We assess the importance of the one-loop radiative corrections first by computing them for a tree level mixing sum constraint, and then for the main Higgs production process ggHgg \to H. We conclude that, for the currently allowed parameter space of these models, the corrections can be at most a few percent. Notably, a non-zero correction can survive when dark matter is present, in the SM-like limit of the Higgs couplings to other SM particles.Comment: 35 pages, 3 figure

    Effects of elevated CO2 and nutrients on the community metabolism of a Cymodocea nodosa bed

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    We assessed the combined effects of elevated CO2 and nutrients on the metabolism of a benthic community dominated by the seagrass Cymodocea nodosa (Ucria) Ascherson in a mesocosm experiment. C. nodosa plants and their associated community were exposed to two CO2 levels simulating future (700 ppm, pH 7.84) and current (360 ppm, pH 8.12) conditions, and two nutrient levels (enriched and ambient concentration) in a total of four treatments (-C-N, -C+N, +C-N, +C+N). Net community production (NCP) was estimated from changes in the concentration of dissolved inorganic carbon in the seawater in light incubations using benthic chambers. The variation pattern of NCP with the ordinance was consistent for all treatments. Although differences among treatments were not statistically significant, average NCP values were lowest under CO2 enrichment conditions. NCP was lower at a high CO2 level and ambient nitrogen concentration compared to when nutrient availability was higher, suggesting that the low nutrient availability may modulate the community response to CO2 enrichment. The results obtained suggest that the stimulation of the net community production of C. nodosa by elevated CO2 concentrations may be curtailed by low nutrient availability

    Algarve, the Mediterranean, and the Atlantic

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    UID/SOC/04647/2019Joaquim Romero Magalhães was to begin with a regional historian rooted in the French Annales tradition of social and economic history. His regional history of the Algarve in the sixteenth to eighteenth centuries overflows into the much wider and evolving complexes within which the Portuguese region was framed-the ageing Mediterranean and the growing Atlantic, and their shifting balance in the weaving of a new world economy. It is in the regional origins of Romero Magalhães's trajectory that we find many of the topics and problems that he developed in his historical travels across the empire.publishersversionpublishe

    High scale impact in alignment and decoupling in two-Higgs doublet models

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    The two-Higgs doublet model (2HDM) provides an excellent benchmark to study physics beyond the Standard Model (SM). In this work we discuss how the behaviour of the model at high energy scales causes it to have a scalar with properties very similar to those of the SM -- which means the 2HDM can be seen to naturally favor a decoupling or alignment limit. For a type II 2HDM, we show that requiring the model to be theoretically valid up to a scale of 1 TeV, by studying the renormalization group equations (RGE) of the parameters of the model, causes a significant reduction in the allowed magnitude of the quartic couplings. This, combined with BB-physics bounds, forces the model to be naturally decoupled. As a consequence, any non-decoupling limits in type II, like the wrong-sign scenario, are excluded. On the contrary, even with the very constraining limits for the Higgs couplings from the LHC, the type I model can deviate substantially from alignment. An RGE analysis similar to that made for type II shows, however, that requiring a single scalar to be heavier than about 500 GeV would be sufficient for the model to be decoupled. Finally, we show that not only a 2HDM where the lightest of the CP-even scalars is the 125 GeV one does not require new physics to be stable up to the Planck scale but this is also true when the heavy CP-even Higgs is the 125 GeV and the theory has no decoupling limit for the type I model.Comment: 28 pages, 19 figure
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