4,440 research outputs found

    The kk-visibility Localization Game

    Full text link
    We study a variant of the Localization game in which the cops have limited visibility, along with the corresponding optimization parameter, the kk-visibility localization number ζk\zeta_k, where kk is a non-negative integer. We give bounds on kk-visibility localization numbers related to domination, maximum degree, and isoperimetric inequalities. For all kk, we give a family of trees with unbounded ζk\zeta_k values. Extending results known for the localization number, we show that for k2k\geq 2, every tree contains a subdivision with ζk=1\zeta_k = 1. For many nn, we give the exact value of ζk\zeta_k for the n×nn \times n Cartesian grid graphs, with the remaining cases being one of two values as long as nn is sufficiently large. These examples also illustrate that ζiζj\zeta_i \neq \zeta_j for all distinct choices of ii and $j.

    Effect of different diets on the development, mortality, survival, food uptake and fecundity of Tupiocoris cucurbitaceus (Hemiptera: Miridae)

    Get PDF
    Several Miridae (Hemiptera) species have been identified as useful predators for biological control of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). There is interest in determining the effects of different diets on Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) in order to facilitate their breeding and use in biological control. Given that mirids can be both phytophagous and zoophytophagous, the developmental time, mortality, survival, feeding and fecundity of this species on tomato and tobacco leaves with and without the addition of T. vaporariorum or Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were studied. To determine embryonic duration, T. cucurbitaceus was allowed to oviposit on tobacco plants for 24 h at 26 °C, 83% RH and a photoperiod of 16:8 h L:D. The time of onset of the first instar nymphs was recorded. Subsequently, these nymphs fed on different diets on 9 cm × 1.5 cm plates under the same environmental conditions. Results showed that diet influences the duration of development in T. cucurbitaceus, with nymphal stadia being shorter and the adult stadium being longer when fed prey than when not fed prey. With the addition of prey, nymphal mortality was generally lower and adult survival was higher. The high consumption of T. vaporariorum eggs by T. cucurbitaceus suggests the need for subsequent studies on the latter for inclusion of this species in biological control programs in greenhouses

    The role of obesity and adipokines in coronary microvascular dysfunction: a systematic review and meta-analysis

    Get PDF
    Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with obesity present structural and functional changes in the heart and in the coronary circulation, which ultimately leads to an increased risk of cardiovascular disease. Obesity is associated with a low chronic state of inflammation which seems to be linked to a compromised coronary vasoreactivity, which is shown to be a forerunner and a long-term predictor of clinically relevant cardiovascular events. Methods A systematic review was performed by searching PubMed, Embase and Cochrane Library database. Selection criteria were applied leading to the inclusion of studies of any level of evidence published in peer-reviewed journals reporting clinical or preclinical results. Relative data were extracted and critically analysed. PRISMA guidelines were applied and risk of bias was assessed, as well as the methodological quality of the included studies. After this assessment, we excluded all the articles with serious risk of bias and/or low quality. Meta-analysis was conducted on the data collected regarding coronary blood flow (CFR) and hyperemic myocardial blood flow (MBF), while for the other parameters a descriptive analysis was performed. Results After applying the described criteria, we included 15 articles on human and animal literature assessed as medium or high quality. The data of 1399 patients were examined, 456 of which with obesity (BMI ≥ 30). A pooled effect size analysis shows that coronary flow reserve (CFR) is significantly reduced in patients with obesity [Random Effect (RE): -47.7%, 95% confidence interval (CI) -80.2% – -15.2%; n = 422]. Increased BMI is associated with reduced CFR. The same trend is found evaluating pharmacological induced stress MBF, which was reduced in patients with obesity [RE: -47.8%, 95% CI -73.7% – -21.8%; n = 409]. Nevertheless, MBF at rest did not show a significant difference in patients with obesity from our analysis [RE: 15%, 95% CI -24% - 53%; n = 409]. Pro-inflammatory adipokines secretion, as leptin and CRP, seems to correlate with a significant decrease of stress-induced MBF and reduced CFR. Conclusions Obesity is associated with a significant higher risk of coronary microvascular disfunction, which is reflected by diminished CFR and stress MBF. Systemic inflammation and the imbalance of adipokines related to obesity has been closely linked to a blunt coronary flow. CMD is a pre-clinical heart conditions that often remains undiagnosed. Further evidence is required to clear out the role of Obesity from a molecular point of view on the coronary endothelium

    New constraints on the 1.4 GHz source number counts and luminosity functions in the lockman hole field

    Get PDF
    We present a study of the 1173 sources brighter than S1.4 GHz = 120 μJy detected over an area of ≃ 1.4 deg2 in the Lockman Hole field. Exploiting the multiband information available in this field for ∼79 per cent of the sample, sources have been classified into radio loud (RL) active galactic nuclei (AGNs), star-forming galaxies (SFGs), and radio quiet (RQ) AGNs, using a variety of diagnostics available in the literature. Exploiting the observed tight anticorrelations between IRAC band 1 or band 2 and the source redshift we could assign a redshift to 177 sources missing a spectroscopic measurement or a reliable photometric estimate. A Monte Carlo approach was used to take into account the spread around the mean relation. The derived differential number counts and luminosity functions at several redshifts of each population show a good consistency with models and with earlier estimates made using data from different surveys and applying different approaches. Our results confirm that below ∼ 300 μJy SFGs+RQ AGNs overtake RL AGNs that dominate at brighter flux densities. We also confirm earlier indications of a similar evolution of RQ AGNs and SFGs. Finally, we discuss the angular correlation function of our sources and highlight its sensitivity to the criteria used for the classification

    Predictions for surveys with the SPICA Mid-infrared Instrument

    Get PDF
    We present predictions for number counts and redshift distributions of galaxies detectable in continuum and in emission lines with the Mid-infrared (MIR) Instrument (SMI) proposed for the Space Infrared Telescope for Cosmology and Astrophysics. We have considered 24 MIR fine-structure lines, four polycyclic aromatic hydrocarbon bands (at 6.2, 7.7, 8.6 and 11.3 mu m) and two silicate bands (in emission and in absorption) at 9.7 and 18.0 mu m. Six of these lines are primarily associated with active galactic nuclei (AGNs), the others with star formation. A survey with the SMI spectrometers of 1-h integration per field of view (FoV) over an area of 1 deg(2) will yield 5 sigma detections of similar or equal to 140 AGN lines and of similar or equal to 5.2 x 10(4) star-forming galaxies, similar or equal to 1.6 x 10(4) of which will be detected in at least two lines. The combination of a shallow (20.0 deg(2), 1.4 x 10(-1) h integration per FoV) and a deep survey (6.9 x 10(-3) deg(2), 635 h integration time), with the SMI camera, for a total of similar to 1000 h, will accurately determine the MIR number counts of galaxies and of AGNs over five orders of magnitude in flux density, reaching values more than one order of magnitude fainter than the deepest Spitzer 24 mu m surveys. This will allow us to determine the cosmic star formation rate (SFR) function down to SFRs more than 100 times fainter than reached by the Herschel Observatory

    Pfas environmental pollution and antioxidant responses: An overview of the impact on human field

    Get PDF
    Due to their unique properties, perfluorinated substances (PFAS) are widely used in multiple industrial and commercial applications, but they are toxic for animals, humans included. This review presents some available data on the PFAS environmental distribution in the world, and in particular in Europe and in the Veneto region of Italy, where it has become a serious problem for human health. The consumption of contaminated food and drinking water is considered one of the major source of exposure for humans. Worldwide epidemiological studies report the negative effects that PFAS have on human health, due to environmental pollution, including infertility, steroid hormone perturbation, thyroid, liver and kidney disorders, and metabolic disfunctions. In vitro and in vivo researches correlated PFAS exposure to oxidative stress effects (in mammals as well as in other vertebrates of human interest), produced by a PFAS-induced increase of reactive oxygen species formation. The cellular antioxidant defense system is activated by PFAS, but it is only partially able to avoid the oxidative damage to biomolecules

    Comportamento das cultivares de soja recomendadas para o Rio Grande do Sul, na safra de 1989/90 em Passo Fundo.

    Get PDF
    bitstream/item/134192/1/ID10384-1989-1990sojaresultados-p50-54.pdfTrabalho apresentado na XVIII Reunião de Pesquisa de Soja da Região Sul, Passo Fundo, 1990

    Quantum properties of dichroic silicon vacancies in silicon carbide

    Get PDF
    The controlled generation and manipulation of atom-like defects in solids has a wide range of applications in quantum technology. Although various defect centres have displayed promise as either quantum sensors, single photon emitters or light-matter interfaces, the search for an ideal defect with multi-functional ability remains open. In this spirit, we investigate here the optical and spin properties of the V1 defect centre, one of the silicon vacancy defects in the 4H polytype of silicon carbide (SiC). The V1 centre in 4H-SiC features two well-distinguishable sharp optical transitions and a unique S=3/2 electronic spin, which holds promise to implement a robust spin-photon interface. Here, we investigate the V1 defect at low temperatures using optical excitation and magnetic resonance techniques. The measurements, which are performed on ensemble, as well as on single centres, prove that this centre combines coherent optical emission, with up to 40% of the radiation emitted into the zero-phonon line (ZPL), a strong optical spin signal and long spin coherence time. These results single out the V1 defect in SiC as a promising system for spin-based quantum technologies
    corecore