1,439 research outputs found

    Recursive bayesian identification of nonlinear autonomous systems

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    This paper concerns the recursive identification of nonlinear discrete-time systems for which the original equations of motion are not known. Since the true model structure is not available, we replace it with a generic nonlinear model. This generic model discretizes the state space into a finite grid and associates a set of velocity vectors to the nodes of the grid. The velocity vectors are then interpolated to define a vector field on the complete state space. The proposed method follows a Bayesian framework where the identified velocity vectors are selected by the maximum a posteriori (MAP) criterion. The resulting algorithms allow a recursive update of the velocity vectors as new data is obtained. Simulation examples using the recursive algorithm are presented

    Penurunan Viabilitas Benih Padi (Oryza Sativa L.) melalui Beberapa Metode Pengusangan Cepat

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    Availability of seed lots with different viabilities is very important as the material for invigoration studies. Acceleratedor rapid aging methods is expected to serve seeds with different viabilities for those studies. The objective of this study was toobtain efficient seeds rapid aging method of rice seeds. The study consisted of three experiments i.e. rapid aging with ethanolgas, soaking seed in liquid ethanol (96%) and exposing seeds to 41 oC temperature and ± 100% relative humidity. Eachexperiment was arranged in a randomized block design with single factor that was length of aging with three replications.There were eight rice varieties used in this study, i. e. three varieties of upland rice, two verieties of lowland rice, and threevarieties of swamp rice. The results showed that the physical aging method could not produce reliable data due to fungusinfection on the treated seed. It was found that generally 60% and 50% viabilities of rice seed could be obtain by ethanol gastreatment for 4.9 and 5.3 hours, as well as by liquid ethanol for 4.0 and 4.4 minutes, respectively. Rapid aging method withliquid ethanol was the fastest and simplest method for decreasing seed viability of rice

    GLUT1 activity contributes to the impairment of PEDF secretion by the RPE

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    Purpose: In this study, we aimed to understand whether glucose transporter 1 (GLUT1) activity affects the secretion capacity of antiangiogenic factor pigment epithelium-derived factor (PEDF) by the RPE cells, thus explaining the reduction in PEDF levels observed in patients with diabetic retinopathy (DR).Methods: Analysis of GLUT1 expression, localization, and function was performed in vitro in RPE cells (D407) cultured with different glucose concentrations, corresponding to non-diabetic (5 mM of glucose) and diabetic (25 mM of glucose) conditions, further subjected to normoxia or hypoxia. The expression of PEDF was also evaluated in the secretome of the cells cultured in these conditions. Analysis of GLUT1 and PEDF expression was also performed in vivo in the RPE of Ins2(Akita) diabetic mice and age-matched wild-type (WT) controls.Results: We observed an increase in GLUT1 under hypoxia in a glucose-dependent manner, which we found to be directly associated with the translocation and stabilization of GLUT1 in the cell membrane. This stabilization led to an increase in glucose uptake by RPE cells. This increase was followed by a decrease in PEDF expression in RPE cells cultured in conditions that simulated DR. Compared with non-diabetic WT mice, the RPE of Ins2Akita mice showed increased GLUT1 overexpression with a concomitant decrease in PEDF expression.Conclusions: Collectively, our data show that expression of GLUT1 is stimulated by hyperglycemia and low oxygen supply, and this overexpression was associated with increased activity of GLUT1 in the cell membrane that contributes to the impairment of the RPE secretory function of PEDF

    BV equivalence with boundary

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    An extension of the notion of classical equivalence of equivalence in the Batalin–Vilkovisky (BV) and Batalin–Fradkin–Vilkovisky (BFV) frameworks for local Lagrangian field theory on manifolds possibly with boundary is discussed. Equivalence is phrased in both a strict and a lax sense, distinguished by the compatibility between the BV data for a field theory and its boundary BFV data, necessary for quantisation. In this context, the first- and second-order formulations of nonabelian Yang–Mills and of classical mechanics on curved backgrounds, all of which admit a strict BV–BFV description, are shown to be pairwise equivalent as strict BV–BFV theories. This in particular implies that their BV complexes are quasi-isomorphic. Furthermore, Jacobi theory and one-dimensional gravity coupled with scalar matter are compared as classically equivalent reparametrisation-invariant versions of classical mechanics, but such that only the latter admits a strict BV–BFV formulation. They are shown to be equivalent as lax BV–BFV theories and to have isomorphic BV cohomologies. This shows that strict BV–BFV equivalence is a strictly finer notion of equivalence of theories

    Predicting iron deficiency and oxidative stress in glycine max through Fourier transform infrared spectroscopy in a time-course experiment

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    Aims: The excessive use of fertilizers is a problem in current agricultural systems, and sustainable farming practices, including precision agriculture, demand the use of new technologies to manage plant stress at an early stage. To sustainably manage iron (Fe) fertilization in agricultural fields, it is urgent to develop early detection methods for Fe deficiency, and linked oxidative stress, in plant leaves. Herein, the potential of using Fourier Transform Infrared (FTIR) spectroscopy for Fe deficiency and oxidative stress detection in soybean plants was evaluated.Methods: After a period of two weeks of hydroponic growth under optimum conditions, soybean plants were grown under Fe-sufficient (Fe+) and Fe-deficient (Fe–) hydroponic conditions for four weeks. Sampling occurred every week, infrared (IR) spectra were acquired and biological parameters (total chlorophyll, anthocyanins and carotenoids concentration, and ABTS and DPPH free radical scavenging ability), mineral concentrations, and the Fe-related genes’ expression - FRO2- and IRT1-like - were evaluated. Results: Two weeks after imposing Fe deficiency, plants displayed decreased antioxidant activity, and increased expression levels of FRO2- and IRT1-like genes. Regarding the PLS models developed to estimate the biological parameters and mineral concentrations, satisfactory calibration models were globally obtained with R2C from 0.93 to 0.99. FTIR spectroscopy was also able to discriminate between Fe + and Fe– plants from an early stage of stress induction with 96.3% of correct assignments. Conclusion: High reproducibility was observed among the different spectra of each sample and FTIR spectroscopy may be an early, non-invasive, cheap, and environmentally friendly technique for IDC management.info:eu-repo/semantics/publishedVersio

    Behaviour of cucumber (Cucumis sativus L.) cultivares under two sowing dates

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    Plant development and fruit production of cucumber cultivars 'Marketer IAC- 2 2 0 5 ' , 'Palomar IAC- 3 0 5 0 ' , 'Santee IAC- 2 4 4 1 ' , 'Verde Paulistano IAC-1336' and 'Aodai 1 - 4 3 2 1 ' were compared under two sowing dates, 5 t n of May and 5 t n of December of 1970 in Campinas, SP, Brazil, in a Yellow Red Latossol. Air temperature ranged from 1 2 , 0°C to 26, 8°C in the first period of culture, and from 18,5°C to 30,2°C in the second period. Adequate cultural practices were provided. When the first female flower appeared in the field, insecticides and fungicides applications were interrupted. For all cultivars, yields were higher and fruit quality was better in the first period of culture. Both in May and December cultures, plants have concentrated their highest yields between the third and the penultima te harvesting dates. 'Santee' presented low yields and the quality of its fruits was poor. 'Aodai' showed the best results as to fruit yield and fruit quality. Yields of the other cultivars were similar. 'Verde Paulistano' presented the latest fruit production. 'Marketer' showed a relatively uniform behaviour in both periods of culture. There were found positive correlations between yield in each harvesting date and total yield, total yield and marketable yield, number of fruits and fruits weight, plant height and yield, and number of lateral branches and yield. The relation between marketable and total yield, and fruit average weight, decreased at the end of the plants cycle.O desenvolvimento e a produção de frutos para consumo in natura dos cultivares de pepino 'Marketer IAC-2205', 'Palomar IAC-3050', 'Santee IAC-2441', 'Verde Paulistano IAC-1386' e 'Aodai 1-4321' foram estudados em duas épocas de semeadura, 5 de maio e 5 de dezembro, em Campinas, SP. Para todos os cultivares, as plantas semeadas em dezembro cresceram mais e desenvolveram-se com maior rapidez que as plantas semeadas em maio; entretanto, as produções das plantas semeadas em maio foram maiores e a qualidade de seus frutos foi superior. Tanto para as plantas semeadas em maio como para as semeadas em dezembro, 'Santee' apresentou produções baixas e frutos de má qualidade. 'Aodai' foi o cultivar mais produtivo e seus frutos foram os de melhor qualidade. As produções dos demais cultivares foram equivalentes. 'Verde Paulistano' apresentou a produção mais tardia. 0 comportamento de 'Marketer' foi pouco afetado pelas variações ambientais. As maiores produções de todos os cultivares, nas duas é poças, foram obtidas entre a terceira e a penúltima colheitas. Foram encontradas correlações positivas entre a produção de cada colheita e a produção total, entre a produção total e a produção comerciável, entre o número de frutos e seu peso, entre produção e a altura da planta e entre produção e número de ramos laterais da planta. A relação entre produções comerciável e total e o peso médio dos frutos diminuíram no final do ciclo das plantas

    What Has Changed During the COVID-19 Pandemic? - The Effect on an Academic Breast Department in Portugal

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    Introduction: One year ago, Portugal entered its first lockdown because of the coronavirus disease-2019 (COVID-19) pandemic. The impact of this on delays in cancer diagnosis and treatment is a major concern, which may negatively affect the outcomes of these patients. Materials and methods: This retrospective, single-center analysis compared the clinical and pathological characteristics of breast cancer (BC) patients referred to a medical oncology first appointment between March 2020 and 2021, with the same period in the previous year. Results: Strikingly, there was a 40% reduction in the number of BC patients during lockdown. However, there was a statistically significant increase in the proportion of metastatic BC patients admitted for the first time for systemic therapy (13.6% vs. 28.9%, p = 0.003). Additionally, a statistically significant increase in the number of patients with bilateral early BC at diagnosis after March 2020 was found (7.2% vs. 1.9%, p = 0.043). Conclusion: These findings support international recommendations for an accelerated restoration of BC screening, to reduce incidence of advanced breast cancer at diagnosis and mitigate the expected impact of the COVID-19 pandemic on patients with cancer. Further work is needed to examine in detail the impact of measures to manage the COVID-19 pandemic on breast cancer outcomes.info:eu-repo/semantics/publishedVersio

    Distinguishing sequences for partially specified FSMs

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    Distinguishing Sequences (DSs) are used inmany Finite State Machine (FSM) based test techniques. Although Partially Specified FSMs (PSFSMs) generalise FSMs, the computational complexity of constructing Adaptive and Preset DSs (ADSs/PDSs) for PSFSMs has not been addressed. This paper shows that it is possible to check the existence of an ADS in polynomial time but the corresponding problem for PDSs is PSPACE-complete. We also report on the results of experiments with benchmarks and over 8 * 106 PSFSMs. © 2014 Springer International Publishing
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