77 research outputs found
Higher secant varieties of embedded in bi-degree
Let denote the Segre-Veronese embedding of via the sections of the sheaf . We study
the dimensions of higher secant varieties of and we prove
that there is no defective secant variety, except possibly for
values of . Moreover when is multiple of , the
secant variety of has the expected dimension for
every .Comment: 8 page
Secant varieties to osculating varieties of Veronese embeddings of .
A well known theorem by Alexander-Hirschowitz states that all the higher secant varieties of (the -uple embedding of \PP n) have the expected dimension, with few known exceptions. We study here the same problem for , the tangential variety to , and prove a conjecture, which is the analogous of Alexander-Hirschowitz theorem, for . Moreover. we prove that it holds for any if it holds for . Then we generalize to the case of , the -osculating variety to , proving, for , a conjecture that relates the defectivity of to the Hilbert function of certain sets of fat points in \PP n
Use of Microsatellites to Study Agricultural Biodiversity and Food Traceability
Molecular markers are useful tools for measuring the genetic diversity among agricultural species. In plants, microsatellites are still the most used markers for germplasm characterization, conservation, and traceability purposes, while in the livestock sector, although having represented the standard for at least two decades, they are still used only for minor farm animal species. In this work, together with a review on the use of microsatellites in livestock, we also illustrate the use of these markers for the characterization of agricultural diversity and food traceability through two case studies: (i) the analysis of genetic diversity in ancient fruit tree cultivars of apple (Malus × domestica Borkh.), pear (Pyrus communis L.), sweet cherry (Prunus avium L.), and sour cherry (Prunus cerasus L.) from Northern Italy and (ii) the molecular authentication of wheat food chain. In the former case, a high genetic variability as well as the presence of different ploidy levels were detected, while in the latter microsatellite markers were shown to be useful for traceability and product authentication along the whole food chain. Overall, the presented evidence confirms the versatility of microsatellites as markers for both agrobiodiversity characterization and food traceability in cultivated plants and farm animals
Educação transpessoal : integrando o saber ao ser no processo educativo
Orientador : Carlos Alberto Vidal FrançaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de EducaçãoDoutorad
Evaluación del aspecto propedéutico del aprendizaje matemático en el ciclo medio
En este trabajo se muestra la implementación, los resultados y las conclusiones de una prueba piloto para evaluar el valor propedéutico del aprendizaje matemático de todo el ciclo medio, teniendo en cuenta los requerimientos del ingreso universitario
Growing Up with Type 1 narcolepsy: Its anthropometric and endocrine features
Study Objectives: To evaluate the effect of type 1 narcolepsy (NT1) on anthropometric and endocrine features in childhood/adolescence, focusing on patterns and correlates of weight, pubertal development, and growth in treated and untreated patients. Methods: We collected anthropometric (height, weight, body mass index (BMI) z-scores), pubertal, metabolic, and endocrine data from 72 NT1 patients at diagnosis and all available premorbid anthropometric parameters of patients from their pediatric files (n = 30). New measurements at 1-y reassessment in patients undergoing different treatments were compared with baseline data. Results: We detected a high prevalence of overweight (29.2%), obesity (25%), metabolic syndrome (18.8%), and precocious puberty (16.1%), but no signs of linear growth alterations at diagnosis. According to anthropometric records, weight gain started soon after NT1 onset. At 1-y follow-up reassessment, sodium oxybate treatment was associated with a significant BMI z-score reduction (-1.29 \ub1 0.30, p < 0.0005) after adjusting for baseline age, sex, sleepiness, and BMI. Conclusions: NT1 onset in children/adolescents is associated with rapid weight gain up to overweight/obesity and precocious puberty without affecting growth. In our study, sodium oxybate treatment resulted in a significant weight reduction in NT1 overweight/obese patients at 1-y follow-up
CFTR Modulation Reduces SARS-CoV-2 Infection in Human Bronchial Epithelial Cells
People with cystic fibrosis should be considered at increased risk of developing severe symptoms of COVID-19. Strikingly, a broad array of evidence shows reduced spread of SARS-CoV-2 in these subjects, suggesting a potential role for CFTR in the regulation of SARS-CoV-2 infection/replication. Here, we analyzed SARS-CoV-2 replication in wild-type and CFTR-modified human bronchial epithelial cell lines and primary cells to investigate SARS-CoV-2 infection in people with cystic fibrosis. Both immortalized and primary human bronchial epithelial cells expressing wt or F508del-CFTR along with CRISPR/Cas9 CFTR-ablated clones were infected with SARS-CoV-2 and samples were harvested before and from 24 to 72 h post-infection. CFTR function was also inhibited in wt-CFTR cells with the CFTR-specific inhibitor IOWH-032 and partially restored in F508del-CFTR cells with a combination of CFTR modulators (VX-661+VX-445). Viral load was evaluated by real-time RT-PCR in both supernatant and cell extracts, and ACE-2 expression was analyzed by both western blotting and flow cytometry. SARS-CoV-2 replication was reduced in CFTR-modified bronchial cells compared with wild-type cell lines. No major difference in ACE-2 expression was detected before infection between wild-type and CFTR-modified cells, while a higher expression in wild-type compared to CFTR-modified cells was detectable at 72 h post-infection. Furthermore, inhibition of CFTR channel function elicited significant inhibition of viral replication in cells with wt-CFTR, and correction of CFTR function in F508del-CFTR cells increased the release of SARS-CoV-2 viral particles. Our study provides evidence that CFTR expression/function is involved in the regulation of SARS-CoV-2 replication, thus providing novel insights into the role of CFTR in SARS-CoV-2 infection and the development of therapeutic strategies for COVID-19
Grassmann secants, identifiability, and linear systems of tensors
For any irreducible non-degenerate variety , we give a
criterion for the -identifiability of . If , then the
-identifiability holds for if and only if the -identifiability
holds for the Segre product . Moreover, if the
-th secant variety of is not defective and it does not fill the ambient
space, then we can produce a family of pairs for which the
-identifiability holds for .Comment: Accepted for the publication: Linear Algebra and its Application
Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop
We use detrended fluctuation analysis (DFA) to study the dynamics of blood
pressure oscillations and its feedback control in rats by analyzing systolic
pressure time series before and after a surgical procedure that interrupts its
control loop. We found, for each situation, a crossover between two scaling
regions characterized by exponents that reflect the nature of the feedback
control and its range of operation. In addition, we found evidences of
adaptation in the dynamics of blood pressure regulation a few days after
surgical disruption of its main feedback circuit. Based on the paradigm of
antagonistic, bipartite (vagal and sympathetic) action of the central nerve
system, we propose a simple model for pressure homeostasis as the balance
between two nonlinear opposing forces, successfully reproducing the crossover
observed in the DFA of actual pressure signals
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