182 research outputs found

    Covering point sets with two disjoint disks or squares

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    Open archive-ElsevierWe study the following problem: Given a set of red points and a set of blue points on the plane, find two unit disks CR and CB with disjoint interiors such that the number of red points covered by CR plus the number of blue points covered by CB is maximized. We give an algorithm to solve this problem in O(n8/3 log2 n) time, where n denotes the total number of points. We also show that the analogous problem of finding two axis-aligned unit squares SR and SB instead of unit disks can be solved in O(nlog n) time, which is optimal. If we do not restrict ourselves to axis-aligned squares, but require that both squares have a common orientation, we give a solution using O(n3 log n) time

    Equilibrium control of nonlinear verticum-type systems, applied to integrated pest control

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    Linear verticum-type control and observation systems have been introduced for modelling certain industrial systems, consisting of subsystems, vertically connected by certain state variables. Recently the concept of verticum-type observation systems and the corresponding observability condition have been extended by the authors to the nonlinear case. In the present paper the general concept of a nonlinear verticum-type control system is introduced, and a sufficient condition for local controllability to equilibrium is obtained. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems. Starting from the integrated pest control model of Rafikov and Limeira (2012) and Rafikov et al. (2012), a nonlinear verticum-type model has been set up an equilibrium control is obtained. Furthermore, a corresponding bioeconomical problem is solved minimizing the total cost of integrated pest control (combining chemical control with a biological one)

    Peribacillus castrilensis sp. nov.: A Plant-Growth-Promoting and Biocontrol Species Isolated From a River Otter in Castril, Granada, Southern Spain

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    A strictly aerobic, chemoheterotrophic, endospore-forming, Gram-positive, rod-shaped bacterial strain N3T was isolated from the feces of a river otter in Castril (Granada, southern Spain). It is halotolerant, motile, and catalase-, oxidase-, ACC deaminase-, and C4- and C8-lipase-positive. It promotes tomato plant growth and can reduce virulence in Erwinia amylovora CECT 222T and Dickeya solani LMG 25993T through interference in their quorum-sensing systems, although other antagonistic mechanisms could also occur. A phylogenetic analysis of the 16S rRNA gene sequence as well as the phenotypic and phylogenomic analyses indicated that the strain N3T is a novel species of the genus Peribacillus, with the highest 16S rRNA sequence similar to that of Bacillus frigoritolerans DSM 8801T (99.93%) and Peribacillus simplex DSM 1321T (99.80%). Genomic digital DNA–DNA hybridization (dDDH) between the strain N3T and Bacillus frigoritolerans DSM 8801T and Peribacillus simplex was 12.8 and 69.1%, respectively, and the average nucleotide identity (ANIb) of strain N3T and Bacillus frigoritolerans DSM 8801T and Peribacillus simplex was 67.84 and 93.21%, respectively. The genomic G + C content was 40.3 mol%. Its main cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Using 16S rRNA phylogenetic and in silico phylogenomic analyses, together with the chemotaxonomic and phenotypic data, we demonstrated that the type strain N3T (=CECT 30509T = LMG 32505T) is a novel species of the genus Peribacillus and the name Peribacillus castrilensis sp. nov. is proposed.Spanish Ministerio de Educación y Ciencia (AGL-2015-68806-R)Spanish Ministry of the Economy and Competitiveness (PID2019-106704RB-100/AEI/10.13039/501100011033)Plan Andaluz de Investigación (Research Group BIO 188)University of Granada Programme (Empleo Garantía Juvenil)Spanish Ministerio de Educación, Cultura y Deporte (FPU15/01717

    Microbial Decontamination of Bee Pollen by Direct Ozone Exposure

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    The bee pollen is a complete and healthy food with important nutritional properties. Usually, bee pollen is consumed dehydrated, but it is possible to market it as fresh frozen pollen, favoring the maintenance of its properties and greatly increasing its palatability, compared to dried pollen. However, fresh frozen pollen maintains a high microbiological load that can include some pathogenic genus to human health. In this work, ozonation combined with drying is applied to reduce the microbiological load. The lowest timing exposure to ozone (30 min) was chosen together with hot-air drying during 15 min to evaluate the shelf-life of treated bee-pollen under cold storage (4 °C), and initial reductions of 3, 1.5, and 1.7 log cycles were obtained for Enterobacteriaceae, mesophilic aerobes, and molds and yeasts counting, respectively. Six weeks after treatment the microbial load was held at a lower level than initially observed in fresh bee-pollen. In addition, ozone treatment did not have a negative impact on the polyphenols evaluated. Likewise, the sensory profile of the bee pollen under different treatments was studied. For all these assays the results have been favorable, so we can say that ozonation of fresh pollen is safe for human consumption, which maintains its polyphenols composition and organoleptically is better valued than dried pollen

    Nanoscopic dynamic mechanical analysis of resin-infiltrated dentine, under in vitro chewing and bruxism events

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    The aim of this study was to evaluate the induced changes in mechanical behavior and bonding capability of resin–infiltrated dentine interfaces, after application of mechanical stimuli. Dentine surfaces were subjected to partial demineralization through 37% phosphoric acid etching followed by the application of an etch-and-rinse dentine adhesive, Single Bond (3M/ESPE). Bonded interfaces were stored in simulated body fluid during 24 h, and then tested or submitted to the mechanical loading challenge. Different loading waveforms were applied: No cycling (I), 24 h cycled in sine (II) or square (III) waves, sustained loading held for 24 h (IV) or sustained loading held for 72 h (V). Microtensile bond strength (MTBS) was assessed for the different groups. Debonded dentine surfaces were studied by field emission scanning electron microscopy (FESEM). At the resin–dentine interface, both the hybrid layer (HL) and the bottom of the hybrid layer (BHL), and both peritubular and intertubular were evaluated using a nanoindenter in scanning mode. The load and displacement responses were used to perform the nano-Dynamic Mechanical analysis and to estimate the complex and storage modulus. Dye assisted Confocal Microscopy Evaluation was used to assess sealing ability. Load cycling increased the percentage of adhesive failures in all groups. Specimens load cycled in held 24 h attained the highest complex and storage moduli at HL and BHL. The storage modulus was maximum in specimens load cycled in held 24 h at peritubular dentine, and the lowest values were attained at intertubular dentine. The storage modulus increased in all mechanical tests, at peritubular dentine. An absence of micropermeability and nanoleakage after loading in sine and square waveforms were encountered. Porosity of the resin–dentine interface was observed when specimens were load cycled in held 72 h. Areas of combined sealing and permeability were discovered at the interface of specimens load cycled in held 24 h. Crack-bridging images appeared in samples load cycled with sine waveform, after FESEM examination.This work was supported by grants MINECO/FEDER MAT2014-52036-P and FIS2013-41821-R

    Effect of Myofascial Therapy on Pain and Functionality of the Upper Extremities in Breast Cancer Survivors: A Systematic Review and Meta-Analysis

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    (1) Objective: The purpose was to analyze the effectiveness of myofascial therapy on musculoskeletal pain and functionality of the upper extremities in female breast cancer survivors, and to evaluate the changes in range of motion, quality of life, and mood state of these patients. (2) Methods: Systematic searches were performed on the MEDLINE/PubMed, Web of Science, Scopus, and Physiotherapy Evidence Databases for articles published until October 2020, in order to identify randomized controlled trials which analyzed the effectiveness of myofascial therapy as compared to a control group, passive treatment, placebo, or another intervention, and allowed co-interventions on female breast cancer survivors. Two reviewers examined the sources individually, calculated the risk of bias and extracted the data (PROSPERO number CRD42020215823). (3) Results: A total of eight RCTs were included. The results suggested that myofascial therapy does not have a greater statistically significant immediate effect on pain intensity (SMD: -0.15; 95% CI -0.48, 0.19), functionality (SMD: -0.17; 95% CI -0.43, 0.09) and range of motion in flexion (SMD: 0.30; 95% CI -0.13, 0.74) than an inactive, passive treatment or another intervention. However, a statistically significant result was observed for the abduction shoulder in favor of the experimental group (SMD: 0.46; 95% CI 0.05, 0.87; p = 0.03). (4) Conclusion: In general, although we found greater overall effects in support of the intervention with myofascial therapy than other control groups/types of interventions, the subgroup analysis revealed inconsistent results supporting myofascial therapy applied to breast cancer survivors

    Effect of zinc-doping in physicochemical properties of dental adhesives

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    Purpose: To evaluate changes in the physicochemical properties, water sorption (WS), solubility (SO), modulus of elasticity (E), ultimate tensile strength (UTS), and microhardness (MH) tests were undertaken in zinc-doped dental adhesives.Methods: Two bonding resins, Adper Single Bond Plus (SB) and Clearfil SE Bond (SEB), were zincdoped by mixing them with 5, 10 or 20wt% of ZnO powder, or with 1 or 2wt% ZnCl2. Resin disks were made of each adhesive blend for the evaluation of WS, SO, and MH, and dumbbell-shaped specimens were prepared for E and UTS testing.Results: An increase in WS and SO was observed for adhesives doped with ZnCl2. A reduction in WS was observed for the adhesive blends containing 10% or 20wt% ZnO, while the SO was not altered in any of the ZnO-doped adhesives. An increase in E values was observed only for the SB adhesive doped with ZnCl2. For SEB-blends, the incorporation of zinc compounds did not alter the E values. UTS values decreased when SEB was doped with ZnO. SBblends doped with 20wt% ZnO significantly increased their MH, and the addition of zinc to the SEB-blends augmented the MH values in all cases.This investigation was supported by grants CICOM/FEDER MAT2014-52036P and AUIP-JA 201

    Effects of Fluoride and Calcium Phosphate-Based Varnishes in Children at High Risk of Tooth Decay: A Randomized Clinical Trial

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    Background: The aim of this study was to investigate the effect of the application of two varnishes—MI Varnish (5% sodium fluoride with CPP-ACP) and Clinpro White Varnish (5% sodium fluoride with fTCP)—applied every three months in children with high caries risk for 12 months on plaque indexes, salivary pH, salivary lactic acid and chemical elements concentrations. Methods: We included 58 children aged 4–12 years, assigned to control (placebo), Clinpro and MI groups. Baseline and three-month saliva samples were taken. We assessed changes in pH, lactic acid concentrations and chemical elements in saliva. Results: At 12 months, all groups showed a nonsignificant increase in pH levels and a reduction in lactic acid, which was greatest in the placebo group. There was a significant reduction in 24Mg (p = <0.001), 31P (p = 0.033) and 66Zn (p = 0.005) levels in the placebo group (p ≤ 0.05), but not in the other elements studied: 23Na, 27Al, 39K, 44Ca, 52Cr, 55Mn, 57Fe, 59Co, 63Cu, 75As, 111Cd, 137Ba, 208Pb and 19F. Conclusions: Neither pH, lactic acid concentrations or most salivary chemical elements were useful in defining patients at high risk of caries or in monitoring the effect of MI Varnish and Clinpro White Varnish after three-month application for 12 months. However, the appearance of new cavities was stopped, and the hygiene index improved, probably due to hygienic and dietary measures and the use of fluoridated toothpaste. Trial registration: ISRCTN registry, ISRCTN13681286
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