64 research outputs found
Phase transitions and stability of dynamical processes on hypergraphs
Hypergraphs naturally represent higher-order interactions, which persistently appear in social interactions, neural networks, and other natural systems. Although their importance is well recognized, a theoretical framework to describe general dynamical processes on hypergraphs is not available yet. In this paper, we derive expressions for the stability of dynamical systems defined on an arbitrary hypergraph. The framework allows us to reveal that, near the fixed point, the relevant structure is a weighted graph-projection of the hypergraph and that it is possible to identify the role of each structural order for a given process. We analytically solve two dynamics of general interest, namely, social contagion and diffusion processes, and show that the stability conditions can be decoupled in structural and dynamical components. Our results show that in social contagion process, only pairwise interactions play a role in the stability of the absorbing state, while for the diffusion dynamics, the order of the interactions plays a differential role. Our work provides a general framework for further exploration of dynamical processes on hypergraphs
Estimates of genetic parameters, growth curve, and environmental effects for Nellore cattle in the Pantanal.
ABSTRACT:The objective was to estimate the growth curves and genetic parameters using random regression methodology for Nellore cattle raised in Pantanal, MS, Brazil (6974 calves; n = 53,233 weights), with at least four weighings per individual. The model considered direct and maternal genetic additives and maternal permanent environmental effects at random. Orthogonal Legendre polynomials of cubic order were used to fit the growth curve. Analyses of variance were performed using the GLM procedure. The model used contained the fixed effects of sex, year of birth, farm, and the covariates calf birth month (linear and quadratic) and cow age at calving (linear and quadratic). The adjusted mean weight at 120 days of age was 93.43 ± 19.78 kg, and for 205 days of age, it was 180.42 ± 26.58 kg. Animals born in the dry season had a higher average weight [kg] (219.57 vs. 211.78, 3.7% higher) and, consequently, had higher weights at 646 days of age. Estimates of direct heritabilities (h2a) ranged from 0.35 to 0.75 (high magnitudes), and maternal heritabilities (h2m) along the trajectory of low magnitudes ranged from 0.03 to 0.08, respectively. The use of random regression to evaluate beef animals allows for adjusting the growth curve and selecting the best animals to be the parents of future generations. RESUMO: O estudo teve como objetivo estimar curvas de crescimento e parâmetros genéticos para Nelore bovinos usando uma metodologia de regressão aleatória. O conjunto de dados incluiu 6.974 bezerros criados no Pantanal, MS, Brasil, e 53.233 registros de peso, com pelo menos quatro pesagens por indivíduo. Os pesos médios aos 120 e 205 dias foram 93,43 kg e 180,42 kg, respectivamente. Os animais nascidos na estação seca tiveram pesos médios mais elevados, levando a pesos mais elevados aos 646 dias. As herdabilidades diretas variaram de 0,35 para 0,75, enquanto as herdabilidades maternas eram baixas (0,03 a 0,08). A regressão aleatória ajusta efetivamente curvas de crescimento e auxilia na seleção de animais superiores para reprodução
Evaluation of linear tomography and cone beam computed tomography accuracy in measuring ridge bone width for planning implant placement
The development of oral implantology has led to the establishment of various image-acquisition methods as important surgical diagnosis tools, such as linear (LT) and cone beam computed tomography (CBCT), indicated for planning implant placement surgeries. However, there still is little information in the literature regarding details on the difference between the accuracy of these methods. Aim: The aim of the present study was to assess the difference between the accuracy of LT and CBCT in measuring ridge bone width. Methods: A sample of ten human skulls was used, totaling 40 edentulous sites, marked with 2-mm gutta-percha balls in the buccal and lingual plates. Buccal-lingual measurements of ridge width were performed on the images of both tomography types. Direct caliper measurements were used as control values, to which all LT and CBCT measurements were compared. Results: CBCT images showed significantly more accurate results in comparison with the direct caliper measurements (p<0.05). Conclusions: CBCT proved more reliable than LT regarding ridge bone measurements for dental implant planning.peer-reviewe
Lack of Galectin-3 Drives Response to Paracoccidioides brasiliensis toward a Th2-Biased Immunity
There is recent evidence that galectin-3 participates in immunity to infections, mostly by tuning cytokine production. We studied the balance of Th1/Th2 responses to P. brasiliensis experimental infection in the absence of galectin-3. The intermediate resistance to the fungal infection presented by C57BL/6 mice, associated with the development of a mixed type of immunity, was replaced with susceptibility to infection and a Th2-polarized immune response, in galectin-3-deficient (gal3−/−) mice. Such a response was associated with defective inflammatory and delayed type hypersensitivity (DTH) reactions, high IL-4 and GATA-3 expression and low nitric oxide production in the organs of infected animals. Gal3−/− macrophages exhibited higher TLR2 transcript levels and IL-10 production compared to wild-type macrophages after stimulation with P. brasiliensis antigens. We hypothesize that, during an in vivo P. brasiliensis infection, galectin-3 exerts its tuning role on immunity by interfering with the generation of regulatory macrophages, thus hindering the consequent Th2-polarized type of response
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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