528 research outputs found

    OFDM-Based Signal Exploitation Using Quadrature Mirror Filter Bank (QMFB) Processing

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    By performing QMFB processing with a given signal it is possible to obtain Frequency-Time (F-T) outputs that represent signal features such as bandwidth (W), center frequency (fc), signal duration (Ts), modulation type (AM, FM, BPSK, QAM, etc), frequency content and time allocation. Because of its unique structure, two widely used signals based on Orthogonal Frequency Division Multiplexing (OFDM) were chosen as signals of interest for demonstration. The general implementation of the QMFB process is described along with the basic structure of OFDM signals related to the physical layer perspective of 802.11a Wi-Fi and 802.16e WiMAX frame structures are described. The adopted methodology is aimed at exploiting signal of interest features accounting for the effects of signal resampling and zeropadding. Computed simulation results are obtained after applying the defined methodology to each signal of interest. Initial time domain and frequency domain responses are presented for each input signal along with the initial and computed resampled parameters for each case. Results for selected QMFB outputs are presented using 2D F-T QMFB plots and 1D average frequency and average time plots. These plots enable qualitative visual assessment such as may be used by a human operator. The 1D responses are computed for the input signal and output QMFB responses and compared using overlay plots for single burst and multiple integrated burst inputs. Resultant time delta t) and frequency (delta f) resolutions were consistent and validate the usefulness of QMFB processing

    DIGESTIVE ENZYMES PROFILE IN OCTOPUS VULGARIS PARALARVAE FED WITH ARTEMIA ENRICHED WITH MARINE PHOSPHOLIPIDS

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    The common octopus (Octopus vulgaris) is an excellent candidate for aquaculture production, however the development of its culture needs to overcome the high paralarvae mortality which points out to zootechnical and nutritional problems. Enhancing the knowledge on paralarvae digestive physiology could increase the possibilities to optimize the diet in order to improve the paralarval growth and survival. In the present study, the effect of fed with Artemia enriched with marine phospholipids on digestive enzyme activity of octopus paralarvae from hatchling and 12 days old paralarvae have been studied

    Current pain management practices for preterm infants with necrotizing enterocolitis:a European survey

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    Background: Necrotizing enterocolitis (NEC) is a highly painful intestinal complication in preterm infants that requires adequate pain management to prevent short- and long-term effects of neonatal pain. There is a lack of international guidelines for pain management in NEC patients. Therefore, this study aims to describe current pain management for NEC patients in European neonatal intensive care units (NICUs). Methods: An online survey was designed and conducted to assess current practices in pain management for NEC patients in European NICUs. The survey was distributed via neonatal societies, digital platforms, and professional contacts. Results: Out of the 259 responding unique European NICUs from 36 countries, 61% had a standard protocol for analgesic therapy, 73% assessed pain during NEC, and 92% treated NEC patients with intravenous analgosedatives. There was strong heterogeneity in the used pain scales and initial analgesic therapy, which mainly included acetaminophen (70%), fentanyl (56%), and/or morphine (49%). A third of NICU representatives considered their pain assessment adequate, and half considered their analgesic therapy adequate for NEC patients. Conclusions: Various pain scales and analgesics are used to treat NEC patients in European NICUs. Our results provide the first step towards an international guideline to improve pain management for NEC patients. Impact: This study provides an overview of current pain management practices for infants with necrotizing enterocolitis (NEC) in European neonatal intensive care units.Choice of pain assessment tools, analgosedatives, and dosages vary considerably among NICUs and countries.A third of NICU representatives were satisfied with their current pain assessment practices and half of NICU representatives with their analgesic therapy practices in NEC patients in their NICU.The results of this survey may provide a first step towards developing a European pain management consensus guideline for patients with NEC.</p

    Mycobacterium tuberculosis Infection in Young Children: Analyzing the Performance of the Diagnostic Tests

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    This study evaluated the performance of the Tuberculin Skin Test (TST) and Quantiferon-TB Gold in-Tube (QFT) and the possible association of factors which may modify their results in young children (0-6 years) with recent contact with an index tuberculosis case. Materials and Methods: A cross-sectional study including 135 children was conducted in Manaus, Amazonas-Brazil. The TST and QFT were performed and the tests results were analyzed in relation to the personal characteristics of the children studied and their relationship with the index case. Results: The rates of positivity were 34.8% (TST) and 26.7% (QFT), with 14.1% of indeterminations by the QFT. Concordance between tests was fair (Kappa = 0.35 P<0.001). Both the TST and QFT were associated with the intensity of exposure (Linear OR = 1.286, P = 0.005; Linear OR = 1.161, P = 0.035 respectively) with only the TST being associated with the time of exposure (Linear OR = 1.149, P = 0.009). The presence of intestinal helminths in the TST+ group was associated with negative QFT results (OR = 0.064, P = 0.049). In the TST- group lower levels of ferritin were associated with QFT+ results (Linear OR = 0.956, P = 0.036). Conclusions: Concordance between the TST and QFT was lower than expected. The factors associated with the discordant results were intestinal helminths, ferritin levels and exposure time to the index tuberculosis case. In TST+ group, helminths were associated with negative QFT results suggesting impaired cell-mediated immunity. The TST-&QFT+ group had a shorter exposure time and lower ferritin levels, suggesting that QFT is faster and ferritin may be a potential biomarker of early stages of tuberculosis infection

    Preliminary Results on Light Conditions Manipulation in Octopus vulgaris (Cuvier, 1797) Paralarval Rearing

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    High paralarvae mortality is a major bottleneck currently hindering the control over the lifecycle of common octopus (Octopus vulgaris Cuvier, 1797). It is believed that this problem might be related to either zoo-technical and/or nutritional aspects. The present paper is focused on the study of different zoo-technical aspects related to light conditions on the rearing of paralarvae, including the effects of polarization in prey ingestion, the use of a blue filter to simulate natural conditions, and the use of focused light to avoid reflections of the rearing tank’s walls. In the first experiment, O. vulgaris paralarvae ingestion of Artemia sp. and copepods (Tisbe sp.) was assessed under either normal or polarized light. In the second experiment, the effect of a blue filter with natural light or focused artificial light on growth and mortality was assessed over 15 days of rearing. Ingestion rate was not influenced by light polarization. Nonetheless, a significantly higher ingestion of Artemia sp. with respect to copepods was observed. The blue filter promoted the use of natural light conditions in Octopus paralarval culture, while focused light reduced the collision of the paralarvae against the walls. However, no significant differences were found in paralarval growth nor survivalEn prens

    Association of leisure time and occupational physical activity with obesity and cardiovascular risk factors in Chile

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    The aim of this study was to investigate the association between physical activity (PA), both occupational (OPA) and during leisure time (LTPA), with obesity and cardiovascular risk factors in Chilean adults. 5,157 participants from the Chilean National Health Survey 2009–2010 were included in this study. OPA and LTPA levels were assessed using the Global Physical Activity Questionnaire. The association between both PA with obesity and cardiovascular risk factors was determined using logistic regression. Our findings showed a significant trend between higher LTPA and lower odds for obesity (OR 0.64 [95% CI: 0.53; 0.76], central obesity 0.52 [0.44; 0.61]) and other cardiovascular risk factors including diabetes (OR: 0.72 [0.55; 0.94]), hypertension (OR: 0.59 [0.50; 0.71]) and metabolic syndrome (OR: 0.62 [0.50; 0.78]). In contrast, OPA was only associated with lower odds of diabetes (OR: 0.79 [0.65; 0.98]) and hypertension (0.85 [0.74; 0.98]). In conclusion, LTPA was associated with a lower risk of all major cardiovascular risk factors, whereas OPA was only associated with a lower risk of diabetes and hypertension

    The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth

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    We present new measurements of cosmic microwave background (CMB) lensing over 94009400 sq. deg. of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at 2.3%2.3\% precision (43σ43\sigma significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. The baseline spectrum is well fit by a lensing amplitude of Alens=1.013±0.023A_{\mathrm{lens}}=1.013\pm0.023 relative to the Planck 2018 CMB power spectra best-fit Λ\LambdaCDM model and Alens=1.005±0.023A_{\mathrm{lens}}=1.005\pm0.023 relative to the ACT DR4+WMAP\text{ACT DR4} + \text{WMAP} best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination S8CMBL≡σ8(Ωm/0.3)0.25S^{\mathrm{CMBL}}_8 \equiv \sigma_8 \left({\Omega_m}/{0.3}\right)^{0.25} of S8CMBL=0.818±0.022S^{\mathrm{CMBL}}_8= 0.818\pm0.022 from ACT DR6 CMB lensing alone and S8CMBL=0.813±0.018S^{\mathrm{CMBL}}_8= 0.813\pm0.018 when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with Λ\LambdaCDM model constraints from Planck or ACT DR4+WMAP\text{ACT DR4} + \text{WMAP} CMB power spectrum measurements. Our lensing measurements from redshifts z∼0.5z\sim0.5--55 are thus fully consistent with Λ\LambdaCDM structure growth predictions based on CMB anisotropies probing primarily z∼1100z\sim1100. We find no evidence for a suppression of the amplitude of cosmic structure at low redshiftsComment: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see companion papers Madhavacheril et al and MacCrann et a

    The Atacama Cosmology Telescope: High-resolution component-separated maps across one-third of the sky

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    Observations of the millimeter sky contain valuable information on a number of signals, including the blackbody cosmic microwave background (CMB), Galactic emissions, and the Compton-yy distortion due to the thermal Sunyaev-Zel'dovich (tSZ) effect. Extracting new insight into cosmological and astrophysical questions often requires combining multi-wavelength observations to spectrally isolate one component. In this work, we present a new arcminute-resolution Compton-yy map, which traces out the line-of-sight-integrated electron pressure, as well as maps of the CMB in intensity and E-mode polarization, across a third of the sky (around 13,000 sq.~deg.). We produce these through a joint analysis of data from the Atacama Cosmology Telescope (ACT) Data Release 4 and 6 at frequencies of roughly 93, 148, and 225 GHz, together with data from the \textit{Planck} satellite at frequencies between 30 GHz and 545 GHz. We present detailed verification of an internal linear combination pipeline implemented in a needlet frame that allows us to efficiently suppress Galactic contamination and account for spatial variations in the ACT instrument noise. These maps provide a significant advance, in noise levels and resolution, over the existing \textit{Planck} component-separated maps and will enable a host of science goals including studies of cluster and galaxy astrophysics, inferences of the cosmic velocity field, primordial non-Gaussianity searches, and gravitational lensing reconstruction of the CMB.Comment: The Compton-y map and associated products will be made publicly available upon publication of the paper. The CMB T and E mode maps will be made available when the DR6 maps are made publi

    The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters

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    We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO measurements (from SDSS and 6dF), we obtain the amplitude of matter fluctuations σ8=0.819±0.015\sigma_8 = 0.819 \pm 0.015 at 1.8% precision, S8≡σ8(Ωm/0.3)0.5=0.840±0.028S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.840\pm0.028 and the Hubble constant H0=(68.3±1.1) km s−1 Mpc−1H_0= (68.3 \pm 1.1)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1} at 1.6% precision. A joint constraint with CMB lensing measured by the Planck satellite yields even more precise values: σ8=0.812±0.013\sigma_8 = 0.812 \pm 0.013, S8≡σ8(Ωm/0.3)0.5=0.831±0.023S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.831\pm0.023 and H0=(68.1±1.0) km s−1 Mpc−1H_0= (68.1 \pm 1.0)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}. These measurements agree well with Λ\LambdaCDM-model extrapolations from the CMB anisotropies measured by Planck. To compare these constraints to those from the KiDS, DES, and HSC galaxy surveys, we revisit those data sets with a uniform set of assumptions, and find S8S_8 from all three surveys are lower than that from ACT+Planck lensing by varying levels ranging from 1.7-2.1σ\sigma. These results motivate further measurements and comparison, not just between the CMB anisotropies and galaxy lensing, but also between CMB lensing probing z∼0.5−5z\sim 0.5-5 on mostly-linear scales and galaxy lensing at z∼0.5z\sim 0.5 on smaller scales. We combine our CMB lensing measurements with CMB anisotropies to constrain extensions of Λ\LambdaCDM, limiting the sum of the neutrino masses to ∑mν<0.12\sum m_{\nu} < 0.12 eV (95% c.l.), for example. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the Λ\LambdaCDM model, while paving a promising path for neutrino physics with gravitational lensing from upcoming ground-based CMB surveys.Comment: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological likelihood data is here: https://lambda.gsfc.nasa.gov/product/act/actadv_prod_table.html ; likelihood software is here: https://github.com/ACTCollaboration/act_dr6_lenslike . Also see companion papers Qu et al and MacCrann et al. Mass maps will be released when papers are publishe
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