79 research outputs found

    Top-philic ALP phenomenology at the LHC: the elusive mass-window

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    We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with the top quark at tree level. We inspect the radiatively induced couplings with the SM fermions and (gauge) bosons and the associated production and decay mechanisms of the ALP. We focus on the most challenging mass window that remains open for a top-philic ALP, i.e., the range between tens and hundreds of GeV. Not only ALP production processes but also virtual ALP contributions to final states with top quarks are considered in detail. We show how searches through resonant production, such as ALP production in association with a ttˉt\bar t pair, are complementary to precision measurements of ttˉt \bar t and ttˉttˉt\bar t t \bar t final states, the latter being competitive or even more powerful for a top-philic ALP in this mass window. Finally, we explore the scenario where the top-philic ALP acts as a mediator to a dark-matter sector, resulting in missing energy signatures at the LHC. We find that the LHC constraints from ttˉt \bar t, ttˉttˉt\bar t t \bar t and ALP + jet production, together with those from ttˉt \bar t + ALP production, can already exclude a large fraction of the parameter space leading to the correct relic abundance.Comment: 45 pages + appendices, 23 figure

    Linee guida per la gestione selvicolturale dei castagneti da frutto

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    Coconut coir as a sustainable nursery growing media for seedling production of the ecologically diverse quercus species

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    Peat, a non-sustainable resource, is still predominately used in forest nurseries. Coconut coir might provide an alternative, renewable, and reliable growing media but few studies have evaluated this media type in forest nurseries. We assessed the influence of pure coir, in combination with various fertilization regimes, on the growth and physiology of three ecologically diverse Quercus species seedlings (Q. robur, Q. pubescens, and Q. ilex) during nursery cultivation. Seedlings were grown using peat and pure coir in combination with three fertilization treatments (standard, K-enriched, and P-enriched). Data were collected for: (1) growth and physiological traits; (2) detailed above- and below-ground morphological traits by destructive analysis; and (3) NPK content in leaves, shoot and roots, and in the growing media, following cultivation. Peat and coir in combination with the various fertilization treatments affected above- and below-ground morphology and, to a lesser extent, the physiological traits of Quercus seedlings. Large effects of the substrate occurred for most morphological variables, with peat being more effective than coir in all studied species. Fertilization also produced significant differences. The effect of K-enriched fertilization on plant growth was clear across the three species and the two growing media. P-enriched fertilization in peat was the only combination that promoted a higher amount of this element in the tissues at the end of cultivation. Despite their smaller size, seedlings produced in coir were compatible with standard Quercus forest stocktype size, and showed a proportionally higher root system development and fibrosity. Our results suggest that coir can be used as an alternative substrate to grow Quercus species seedlings, and that fertilization can offset coir deficiencies in chemical properties. As several functional traits drive planting performance under varying environmental conditions. according to the Target Plant Concept, coir might thus serve as an acceptable material for seedling cultivation in some cases

    Valorizzazione della produzione legnosa dei boschi di castagno

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    In Italy chestnut stands evolution has been historically and strictly linked to both ecological and socioeconomic factors and the changes over the centuries have nowadays led to three main stands types: cultivated orchards, abandoned orchards and stands managed for wood production, mainly coppices. This last type is spread on 593,242 hectares and the importance of these forests consists of the high production potential in quantitative and qualitative terms and of the variety of timber assortments they can provide. Suitable silvicultural systems, based on diversified rotation length, can be adopted to improve wood production both from a quantitative and qualitative point of view

    Stand structure attributes in potential Old-Growth Forests in the Apennines, Italy

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    The aim of this paper is to provide early feedback on stand structure attributes in Italian Apennines forests that could be considered Old Growth Forests in the Mediterranean Eco-Region. Few data are nowadays available relating to this Region. 10 forest reserves across the Apennines were selected and a census of trees and structural parameters was conducted in permanent plots (0.16-1.0 ha), one plot for each selected forest stand. Dimensional and structural characters indicate a large variability among the investigated forest stands. The considered parameters are compared with those reported for other European countries. Old growth features and characteristics of each indicator should be revised and referred to the particular climatic and biogeographic context. The chosen forest study sites are to be considered old if related to common Apennine stands but, in some cases, their development stage is not so close to “truly” Old Growth Forest. Permanent plots allow future investigations on dynamic processes leading to real Old Growth Mediterranean Forests in Italian Apennines

    Metabolic abnormalities in polycystic ovary syndrome women: obese and non obese

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    OBJETIVO: Comparar as características metabólicas de mulheres jovens do sudeste brasileiro, obesas e não obesas com síndrome dos ovários policísticos (SOP). MÉTODOS: Estudo transversal que incluiu 218 mulheres de idade reprodutiva com diagnóstico de SOP - 90 mulheres não obesas (IMC entre 18,5 e 29,9 kg/m²) e 128 pacientes obesas (IMC &gt;30 kg/m²), selecionadas no momento do diagnóstico. Foram comparadas as frequências de resistência insulínica (RI), intolerância à glicose (IG), síndrome metabólica (MetS) e diabetes mellitus tipo 2 (DM2) e os valores médios de colesterol total (CT), triglicérides (TG), lipoproteínas de alta (LDL) e baixa densidade (HDL), entre as pacientes obesas e não obesas com SOP. Foram comparadas também as características clínicas e hormonais (hormônio folículo estimulante, luteinizante, prolactina, hormônio tireoestimulante, testosterona total, sulfato de dehidroepiandrostenediona e 17-hidroxiprogesterona) nos dois grupos. A análise estatística foi realizada com o auxílio do software SAS 9.0. Para análise das variáveis com distribuição normal, utilizou-se o teste t de Student não pareado; na ausência desta característica, o teste utilizado foi Mann-Whitney bicaudal. Para as variáveis qualitativas utilizou-se o teste Exato de Fisher. Em todas as análises, foi considerado o nível de significância de 5% (p<0,05). RESULTADOS: As frequências de RI, IG e MetS foram significativamente mais elevadas em pacientes com SOP obesas do que não obesas (66,7, 29,9 e 63% versus 24,7, 12,2 e 16.4%, respectivamente). As pacientes obesas apresentaram maiores níveis de CT e TG (189,8±35.8 mg/dL e 145.4±71.1 mg/dL, respectivamente) do que as não obesas (172,1±38.4 mg/dL e 99,3±54 mg/dL, respectivamente). Ambos os grupos apresentaram níveis médios de HDL abaixo de 50 mg/dL. CONCLUSÕES: Mulheres obesas jovens com SOP apresentam maior frequência de RI, IG e SM do que as não obesas. Todavia, a ocorrência dos distúrbios metabólicos é elevada também na pacientes não obesas, sugerindo que a presença da síndrome favoreça o desenvolvimento de comorbidades metabólicas, com potenciais repercussões a médio e longo prazos.PURPOSE: To compare the metabolic characteristics of obese and non-obese young women with polycystic ovary syndrome (POS) from the Brazilian Southeast. METHODS: This was a cross-sectional study conducted on 218 women of reproductive age with a diagnosis of POS - 90 non-obese women (BMI between 18.5 and 29.9 kg/m²), and 128 obese patients (BMI &gt;30 kg/m²) selected at the time of diagnosis. The frequency of insulin resistance (IR), glucose intolerance (GI), metabolic syndrome (MetS) and type 2 diabetes mellitus (DM2) and mean values of total cholesterol (TC), triglycerides (TG), high-density (HDL) and low-density lipoproteins (LDL), were compared between obese and non-obese patients with POS. The two groups were also compared in terms of clinical and hormonal characteristics (follicle stimulating hormone, prolactin, thyroid stimulating hormone, total testosterone, dihydroepiandrostenedione sulfate, and 17-hydroxyprogesterone). Statistical analysis was performed using the SAS 9.0 software. Quantitative variables were compared by the Student´s t-test (data with normal distribution) or by the Mann-Whitney test (non-parametric distribution). Qualitative variables were compared by the Fisher test. The level of significance was set at 5% (p<0.05) in all analyses. RESULTS: The frequency of IR, GI and MetS was significantly higher in obese than non-obese patients with POS (66.7, 29.9, and 63% versus 24.7, 12.2, and 16.4%, respectively). Obese patients had higher TC and TG levels (189.8±35.8 mg/dL and 145.4±71.1 mg/dL, respectively) than non-obese patients (172.1±38.4 mg/dL and 99.3±54 mg/dL, respectively). Both groups had mean HDL levels below 50 mg/dL. CONCLUSIONS: Young obese women with POS have a higher frequency of IR, GI and MS than non-obese. However, the occurrence of metabolic disorders is elevated also in the non-obese patients, suggesting that the presence of the syndrome may favor the development of metabolic comorbidities with potential medium- and long-term repercussions
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