13 research outputs found
Heavy-flavor production and medium properties in high-energy nuclear collisions --What next?
Open and hidden heavy-flavor physics in high-energy nuclear collisions are entering a new and exciting stage towards reaching a clearer understanding of the new experimental results with the possibility to link them directly to the advancement in lattice Quantum Chromo-Dynamics (QCD). Recent results from experiments and theoretical developments regarding open and hidden heavy-flavor dynamics have been debated at the Lorentz Workshop Tomography of the Quark-Gluon Plasma with Heavy Quarks, which was held in October 2016 in Leiden, The Netherlands. In this contribution, we summarize identified common understandings and developed strategies for the upcoming five years, which aim at achieving a profound knowledge of the dynamical properties of the quark-gluon plasma
Native diversity buffers against severity of non-native tree invasions
Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5–7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions
Integrated global assessment of the natural forest carbon potential
Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets
Extended time of cold ischemia and its influence on the physiological function of human adult pancreatic islets
In this study we compared the effects of duration of cold ischemia (longer and shorter ischemia) on the yield, viability and preservation of the physiological function and insulin secretion of adult human pancreatic islets in short-term (seven days) culture. Based on the tested parameters, we established that there are no major differences between these two test groups and that the storage and transport of pancreatic tissue in physiological solution at 4 degrees C gives quite satisfactory results
Dietary fat intake as risk factor for the development of diabetes: Multinational, multicenter study of the Mediterranean Group for the Study of Diabetes (MGSD)
OBJECTIVE - To investigate the role of dietary factors in the development of type 2 diabetes. RESEARCH DESIGN AND METHODS - In the context of the Multinational MGSD Nutrition Study, three groups of subjects were studied: 204 subjects with recently diagnosed diabetes (RDM), 42 subjects with undiagnosed diabetes (UDM) (American Diabetes Association criteria - fasting plasma glucose [FPG] ≥ 126 mg/dl), and 55 subjects with impaired fasting glucose (1FG) (FPG ≥ 110 and <126 mg/dl). Each group was compared with a control group of nondiabetic subjects, matched one by one for center, sex, age, and BMI. Nutritional habits were evaluated by a dietary history method, validated against the 3-day diet diary. In RDM, the questionnaire referred to the nutritional habits before the diagnosis of diabetes. Demographic data were collected, and anthropometrical and biochemical measurements were taken. RESULTS - Compared with control subjects, RDM more frequently had a family history of diabetes (49.0 vs. 14.2%; P < 0.001), exercised less (exercise index 53.5 vs. 64.4; P < 0.01), and more frequently had sedentary professions (47.5 vs. 27.4%; P < 0.001). Carbohydrates contributed less to their energy intake (53.5 vs. 55.1%; P < 0.05), whereas total fat (30.2 ± 0.5 vs. 27.8 ± 0.5%; P < 0.001) and animal fat (12.2 ± 0.3 vs. 10.8 ± 0.3%; P < 0.01) contributed more and the plant-to-animal fat ratio was lower (1.5 ± 0.1 vs. 1.8 ± 0.1; P < 0.01). UDM more frequently, had a family history of diabetes (38.1 vs. 19.0%; P < 0.05) and sedentary professions (58.5 vs. 34.1%; P < 0.05), carbohydrates contributed less to their energy intake (47.6 ± 1.7 vs. 52.8 ± 1.4%; P < 0.05), total fat (34.7 ± 1.5 vs. 30.4 ± 1.2%; P < 0.05) and animal fat (14.2 ± 0.9 vs. 10.6 ± 0.7%; P < 0.05) contributed more, and the plant-to-animal fat ratio was lower (1.6 ± 0.2 vs. 2.3 ± 0.4; P < 0.05). IFG differed only in the prevalence of family history of diabetes (32.7 vs. 16.4%; P < 0.05). CONCLUSIONS - Our data support the view that increased animal fat intake is associated with the presence of diabetes
Drag and diffusion of heavy quarks in a hot and anisotropic QCD medium
The propagation of heavy quarks (HQs) in a medium was quite often modeled by
the Fokker-Plank (FP) equation. Since the transport coefficients, related to
drag and diffusion processes are the main ingredients in the FP equation, the
evolution of HQs is thus effectively controlled by them. At the initial stage
of the relativistic heavy ion collisions, asymptotic weak-coupling causes the
free-streaming motions of partons in the beam direction and the expansion in
transverse directions are almost frozen, hence an anisotropy in the momentum
space sets in. Since HQs are too produced in the same time therefore the study
of the effect of momentum anisotropy on the drag and diffusion coefficients
becomes advertently desirable. In this article we have thus studied the drag
and diffusion of HQs in the anisotropic medium and found that the presence of
the anisotropy reduces both drag and diffusion coefficients. In addition, the
anisotropy introduces an angular dependence to both the drag and diffusion
coefficients, as a result both coefficients get inflated when the partons are
moving transverse to the direction of anisotropy than parallel to the direction
of anisotropy.Comment: 9 pages, 6 figure