4,556 research outputs found

    Acoustic Events in the Solar Atmosphere from Hinode/SOT NFI observations

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    We investigate the properties of acoustic events (AEs), defined as spatially concentrated and short duration energy flux, in the quiet sun using observations of a 2D field of view (FOV) with high spatial and temporal resolution provided by the Solar Optical Telescope (SOT) onboard \textit{Hinode}. Line profiles of Fe \textsc{i} 557.6 nm were recorded by the Narrow band Filter Imager (NFI) on a 82"×82"82" \times 82" FOV during 75 min with a time step of 28.75 s and 0.08"" pixel size. Vertical velocities were computed at three atmospheric levels (80, 130 and 180 km) using the bisector technique allowing the determination of energy flux in the range 3-10 mHz using two complementary methods (Hilbert transform and Fourier power spectra). Horizontal velocities were computed using local correlation tracking (LCT) of continuum intensities providing divergences. The net energy flux is upward. In the range 3-10 mHz, a full FOV space and time averaged flux of 2700 W m−2^{-2} (lower layer 80-130 km) and 2000 W m−2^{-2} (upper layer 130-180 km) is concentrated in less than 1% of the solar surface in the form of narrow (0.3"") AE. Their total duration (including rise and decay) is of the order of 10310^{3} s. Inside each AE, the mean flux is 1.61051.6 10^{5} W m−2^{-2} (lower layer) and 1.21051.2 10^{5} W m−2^{-2} (upper). Each event carries an average energy (flux integrated over space and time) of 2.510192.5 10^{19} J (lower layer) to 1.910191.9 10^{19} J (upper). More than 10610^{6} events could exist permanently on the Sun, with a birth and decay rate of 3500 s−1^{-1}. Most events occur in intergranular lanes, downward velocity regions, and areas of converging motions.Comment: 18 pages, 10 figure

    Determinants of Contraceptive Options among Postpartum Women Attending Selected Health Care Facilities in Nigeria: A Cross-Sectional Study

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    Introduction: Differences in availability and choices of contraceptive methods among postpartum women have been found to influence their quality of life as the fertility rate is very high, and the contraceptive usage rate persistently remains low in Nigeria. Objectives: This study assessed the determinants of contraceptive options among postpartum women in Nigeria. Methods: Two Local Governments were randomly selected from the four Local Governments. Within these two local governments, five health facilities were selected. A multistage sampling technique was used to select the 240 respondents, while a structured questionnaire was used to collect data. Results: Findings from the study indicated that 81.7% of the respondents have planned to have their current baby, and about 65.4% of the women have resumed sexual activities since delivery. Of those who have resumed sexual activities, the majority, 91.1% did so 6 weeks after delivery. Some form of contraceptive usage was prominent among 59.2% of the respondents, as the most common contraceptive method used was withdrawal (24.8%). Contraceptive prevalence was slightly lower for urban respondents than rural respondents, although the relationship was not significant. Also, there was a statistically significant relationship between the current use of contraceptives and resumption of sexual activities since delivery (p = .001), resumption of menstruation (p = .001), and information received about postpartum family planning (p = 0.013). Conclusion: Findings from this study emphasize the urgent need for enhanced accessibility and availability of contraceptive methods, with a parallel emphasis on targeted interventions and effective communication strategies to promote contraceptive uptake and family planning. Addressing these determinants is vital in improving postpartum women's overall quality of life in the study area

    SmartEx: a case study on user profiling and adaptation in exhibition booths

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    An investigation into user profiling and adaptation with exhibition booth as a case study is reported. First a review of the field of exhibitions and trade fairs and a summary introduction to adaptation and profiling are given. We then introduce three criteria for the evaluation of exhibition booth: effectiveness, efficiency and affect. Effectiveness is related the amount of information collected, efficiency is a measurement of the time taken to collect the information, and affect is the perception of the experience and the mood booth visitors have during and after their visit. We have selected these criteria to assess adaptive and profiled exhibition booths, we call smart exhibition (SmartEx). The assessment is performed with an experiment with three test conditions (non-profiled/non adaptive, profiled/non-adaptive and profiled adaptive presentations). Results of the experiment are presented along discussion. While there is significant improvements of effectiveness and efficiency between the two-first test conditions, the improvement is not significant for the last test condition, for reasons explained. As for the affect, the results show that it has an under-estimated importance in people minds and that it should be addressed more carefully

    Blood Biochemical Profile and Carcass Characteristics of Weaner Rabbits Fed Varying Inclusion Levels of Gamba Grass (Andropogon gayanus Kunth.) Forage

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    A study was conducted to investigate the effect of varying inclusion levels of Gamba grass (Andropogon gayanus Kunth) forage on haematological, blood biochemical and carcass characteristics of weaner rabbits. A total of 20 male rabbits of mixed breeds with an average initial weight of 450g were randomly assigned into four dietary treatments containing varying inclusion levels of gamba grass forage (0, 5, 10 and 15%). There were four rabbits per treatment, each serving as a replicate in a completely randomized design. Blood samples were collected at the end of eight (8) week feeding period before the carcass analysis.. Results indicated that there were significant (P<0.05) increasing trend in the haematological and blood biochemical parameters measured. There were 51% and 55% increases (P<0.05) in total protein (8.53 vs. 5.65g/dl) and calcium ions (2.65 vs. 1.18mmol/dl) in rabbits fed diet containing 15% inclusion level of gamba grass forage compared to the control. However, there were 10% and 17% decreases (P<0.05) in white blood cells (4.92 vs. 4.43%) and alkaline phosphate (89.33 vs. 76.33IU/dl) in rabbits fed the control diet than those fed diet containing 15% inclusion level of gamba grass. Also, there were 13% and 49% increase (P<0.05) in dressing percentage (54.80 vs. 48.60%) and weight of thigh (16.95 vs. 11.35%) in rabbits fed diet containing 15% inclusion level of gamba grass forage compared to the control. However, length of small intestine and weights of heart, head, stomach and small intestines were similar (P>0.05) across the treatments, respectively. It was concluded that gamba grass forage can be included up to 15% in the diet of weaner rabbits, without adverse effect on haematological, biochemical profile and carcass characteristics of the rabbits in Northern Guinea savanna of Nigeria. Gamba grass (Andropogon gayanus Kunth) forage can be included in the diets of weaner rabbits to reduce cost of production.Keywords: Blood, competition, carcass, feed, gamba, Nigeria, rabbi

    Compressibility of a two-dimensional hole gas in tilted magnetic field

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    We have measured compressibility of a two-dimensional hole gas in p-GaAs/AlGaAs heterostructure, grown on a (100) surface, in the presence of a tilted magnetic field. It turns out that the parallel component of magnetic field affects neither the spin splitting nor the density of states. We conclude that: (a) g-factor in the parallel magnetic field is nearly zero in this system; and (b) the level of the disorder potential is not sensitive to the parallel component of the magnetic field

    Insights into infusion-based targeted drug delivery in brain: perspectives, challenges and opportunities

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    Targeted drug delivery in the brain is instrumental in the treatment of lethal brain diseases, such as glioblastoma multiforme, the most aggressive primary central nervous system tumour in adults. Infusion-based drug delivery techniques, which directly administer to the tissue for local treatment, as in convection-enhanced delivery (CED), provide an important opportunity; however, poor understanding of the pressure-driven drug transport mechanisms in the brain has hindered its ultimate success in clinical applications. In this review, we focus on the biomechanical and biochemical aspects of infusion-based targeted drug delivery in the brain and look into the underlying molecular level mechanisms. We discuss recent advances and challenges in the complementary field of medical robotics and its use in targeted drug delivery in the brain. A critical overview of current research in these areas and their clinical implications is provided. This review delivers new ideas and perspectives for further studies of targeted drug delivery in the brain

    Assessing the Impact of Blood Pressure on Cardiac Function Using Interpretable Biomarkers and Variational Autoencoders

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    Maintaining good cardiac function for as long as possible is a major concern for healthcare systems worldwide and there is much interest in learning more about the impact of different risk factors on cardiac health. The aim of this study is to analyze the impact of systolic blood pressure (SBP) on cardiac function while preserving the interpretability of the model using known clinical biomarkers in a large cohort of the UK Biobank population. We propose a novel framework that combines deep learning based estimation of interpretable clinical biomarkers from cardiac cine MR data with a variational autoencoder (VAE). The VAE architecture integrates a regression loss in the latent space, which enables the progression of cardiac health with SBP to be learnt. Results on 3,600 subjects from the UK Biobank show that the proposed model allows us to gain important insight into the deterioration of cardiac function with increasing SBP, identify key interpretable factors involved in this process, and lastly exploit the model to understand patterns of positive and adverse adaptation of cardiac function
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