2,234 research outputs found

    Subjective quality assessment in stereoscopic video based on analyzing parallax and disparity

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    Disparity may cause visual discomfort. Pairs of video sequences with different levels of parallax, both negative and positive, were presented together to the observers. The observers evaluated the cases in which visual discomfort occurred after visualizing the transition on each pair

    Proposal for Characterization of 3DTV Video Sequences Describing Parallax Information

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    Recommendations such as P.910 suggests parameters TI (temporal information) and SI (spatial information) for characterizing video sequences for quality assessment. In this paper, we suggest two additional parameter based on disparity called SPI (spatial parallax information) and TPI (temporal parallax information) to characterize 3DTV video sequences for this purpose

    Insertion of impairments in test video sequences for quality assessment based on psychovisual characteristics

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    Assessing video quality is a complex task. While most pixel-based metrics do not present enough correlation between objective and subjective results, algorithms need to correspond to human perception when analyzing quality in a video sequence. For analyzing the perceived quality derived from concrete video artifacts in determined region of interest we present a novel methodology for generating test sequences which allow the analysis of impact of each individual distortion. Through results obtained after subjective assessment it is possible to create psychovisual models based on weighting pixels belonging to different regions of interest distributed by color, position, motion or content. Interesting results are obtained in subjective assessment which demonstrates the necessity of new metrics adapted to human visual system

    Aislamiento e identificación de volátiles de Physalis philadelphica LAM

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    El objetivo de este trabajo fue aislar e identificar los componentes volátiles del tomate de cáscara Physalis philadelphica Lam. Por lavado con hexano, aireación dinámica (AD) y micro extracción en fase sólida (MEFS) se aislaron volátiles de P. philadelphica, los cuales se analizaron e identificaron por cromatografía de gases (CG) y CG acoplada a espectrometría de masas (CG-EM). Los compuestos recolectados por AD y MEFS se identificaron como salicilato de metilo, β-cariofileno, β-pineno, alcohol bencílico, 3-careno, β-elemeno, decanal y germacreno D. Los componentes recolectados lavando las plantas con hexano fueron β-cariofileno, linolenato de etilo, salicilato de metilo, β-pineno, ácido hexadecanoico, linolenato de metilo, alcohol bencílico, germacreno D, 3-careno, β-elemeno y decanal

    Cycle scheduling for in vitro fertilization with oral contraceptive pills versus oral estradiol valerate: a randomized, controlled trial

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    BACKGROUND: Both oral contraceptive pills (OCPs) and estradiol (E(2)) valerate have been used to schedule gonadotropin-releasing hormone (GnRH) antagonist in vitro fertilization (IVF) cycles and, consequently, laboratory activities. However, there are no studies comparing treatment outcomes directly between these two pretreatment methods. This randomized controlled trial was aimed at finding differences in ongoing pregnancy rates between GnRH antagonist IVF cycles scheduled with OCPs or E(2) valerate. METHODS: Between January and May 2012, one hundred consecutive patients (nonobese, regularly cycling women 18–38 years with normal day 3 hormone levels and <3 previous IVF/ICSI attempts) undergoing IVF with the GnRH antagonist protocol were randomized to either the OCP or E(2) pretreatment arms, with no restrictions such as blocking or stratification. Authors involved in data collection and analysis were blinded to group assignment. Fifty patients received OCP (30 μg ethinyl E(2)/150 μg levonorgestrel) for 12–16 days from day 1 or 2, and stimulation was started 5 days after stopping OCP. Similarly, 50 patients received 4 mg/day oral E(2) valerate from day 20 for 5–12 days, until the day before starting stimulation. RESULTS: Pretreatment with OCP (mean±SD, 14.5±1.7 days) was significantly longer than with E(2) (7.8±1.9 days). Stimulation and embryological characteristics were similar. Ongoing pregnancy rates (46.0% vs. 44.0%; risk difference, –2.0% [95% CI –21.2% to 17.3%]), as well as implantation (43.5% vs. 47.4%), clinical pregnancy (50.0% vs. 48.0%), clinical miscarriage (7.1% vs. 7.7%), and live birth (42.0% vs. 40.0%) rates were comparable between groups. CONCLUSIONS: This is the first study to directly compare these two methods of cycle scheduling in GnRH antagonist cycles. Our results fail to show statistically significant differences in ongoing pregnancy rates between pretreatment with OCP and E(2) for IVF with the GnRH antagonist protocol. Although the study is limited by its sample size, our results may contribute to a future meta-analysis. An interesting future direction would be to extend our study to women with decreased ovarian reserve, as these are the patients in whom an increase in oocyte yield—due to the hypothetical beneficial effect of steroid pretreatment on follicular synchronization—could more easily be demonstrated. TRIAL REGISTRATION: ClinicalTrials.gov http://NCT01501448

    Excessive age-related decline in functional ovarian reserve in infertile women: prospective cohort of 15,500 women

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    Context: Whether infertile women exhibit accelerated ovarian aging and whether a low ovarian reserve is overrepresented in infertility populations is not known. Objective: To compare the age-related decline in antral follicle count (AFC), a biomarker of the ovarian reserve, in fertile and infertile women. Design: Cross-sectional data from a large prospective cohort study conducted from January 2013 to December 2014. Setting: Thirteen fertility centers across Spain. Patients or Other Participants: Consecutive women aged 18 to 45 years of age attending the fertility centers either seeking fertility treatment or as fertile women wishing to act as potential oocyte donors. Intervention(s): Standardized AFC assessment on day 2 to 4 of the cycle. Main Outcome Measure(s): Age-related decline of AFC for both fertile and infertile women. Results: A total of 15 500 women, of whom 5722 were potential donors and 9778 were patients seeking fertility treatment, participated in the study. Average AFC was greater in potential oocyte donors than in infertile women (20 [interquartile range, 16–24] vs 10 [interquartile range, 6–15], respectively; P &lt; .001), a difference that was maintained after adjustment for age (P &lt; .001) in a model predicting log(AFC) from donor vs infertility, adjusting for 2-year age bands. The age-related decline in AFC was much steeper in infertile women compared with that of potential oocyte donors, with an increased prevalence of a low ovarian reserve (AFC &lt; 5) at all ages in infertile women. Conclusions: The age-related decline in AFC was substantially greater in infertility patients than potential oocyte donors. Overrepresentation in infertility populations of women with low ovarian reserve may be an additional functional cause of infertility

    Molecular elucidation of CO2 methanation over a highly active, selective and stable LaNiO3/CeO2-derived catalyst by in situ FTIR and NAP-XPS

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    The CO2 methanation mechanism over the highly active (TOF=75.1 h−1), selective (>92%) and stable 10% LaNiO3/CeO2-derived catalyst is still unresolved. The surface of the catalyst is monitored under hydrogenation (H2), oxidizing (CO2) and CO2 methanation (H2 +CO2) conditions by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) using synchrotron radiation. Meanwhile, the main reaction intermediates are identified by in situ FTIR analysis. NAP-XPS experiments confirm that LaNiO3 perovskite reduction leads to the ex-solution of Ni0 nanoparticles and Ni2+single bondCeO2−x and Ni2+single bondLa2O3 interfaces conformation, favouring the CO2 adsorption and the H2 dissociation/transfer. In situ FTIR experiments combined with the C1s spectra (NAP-XPS) suggest that the CO2 activation occurs on CeO2−x (oxygen vacancies and OH–) at low temperatures, in the form of bicarbonates; whereas, mono-/bidentate carbonates are formed on different strength La2O3 sites at increasing temperatures. These species are consecutively reduced to formates, as the main reaction intermediate, and methane by the H spilled from Ni0 nanoparticles near to NiOsingle bondCeO2−x and NiOsingle bondLa2O3 interfaces.Support for this study was provided by Projects PID2019–105960RB-C21 and PID2019–105960RB-C22 by MCIN/AEI/10.13039/501100011033, the Basque Government (Project IT1509–2022), Generalitat Valenciana (CIPROM/2021/74) and ALBA synchrotron. One of the authors (JAOC) acknowledges the postdoctoral research grant (DOCREC20/49) provided by the University of the Basque Country (UPV/EHU)

    Aromatase inhibitors in post-menopausal endometriosis

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    Postmenopausal endometriosis is a rare clinical condition. The diagnosis and treatment of an endometriotic lesion in postmenopausal women is complicated. First line treatment choice should be surgical, given that there is a potential risk of malignancy. Medical treatment may be considered as second line or as an alternate first line treatment whenever surgery is contradicted and aims to alter the hormonal pathway leading to endometriosis progress. Different hormonal regimens have been administered to these patients, with conflicting however results. Aromatase inhibitors (AIs) represent one of the most recently used drugs for postmenopausal endometriosis. Clinical data for the use of (AIs) in postmenopausal patients is scarce. Up to date only 5 case reports are available regarding the use of these agents in postmenopausal women. Although definite conclusions may be premature, AIs appear to considerably improve patients' symptoms and reduce endometriotic lesions size. Nonetheless the subsequent induced reduction in estrogen production, leads to certain short-term and long-term adverse effects. Despite the limited available data, AIs appear to represent a new promising method which may improve symptoms and treat these patients, either as first line treatment, when surgery is contraindicated or as a second line for recurrences following surgical treatment. However, careful monitoring of patients' risk profile and further research regarding long-term effects and side-effects of these agents is essential prior implementing them in everyday clinical practice

    NeuroEditor: a tool to edit and visualize neuronal morphologies

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    The digital extraction of detailed neuronal morphologies from microscopy data is an essential step in the study of neurons. Ever since Cajal’s work, the acquisition and analysis of neuron anatomy has yielded invaluable insight into the nervous system, which has led to our present understanding of many structural and functional aspects of the brain and the nervous system, well beyond the anatomical perspective. Obtaining detailed anatomical data, though, is not a simple task. Despite recent progress, acquiring neuron details still involves using labor-intensive, error prone methods that facilitate the introduction of inaccuracies and mistakes. In consequence, getting reliable morphological tracings usually needs the completion of post-processing steps that require user intervention to ensure the extracted data accuracy. Within this framework, this paper presents NeuroEditor, a new software tool for visualization, editing and correction of previously reconstructed neuronal tracings. This tool has been developed specifically for alleviating the burden associated with the acquisition of detailed morphologies. NeuroEditor offers a set of algorithms that can automatically detect the presence of potential errors in tracings. The tool facilitates users to explore an error with a simple mouse click so that it can be corrected manually or, where applicable, automatically. In some cases, this tool can also propose a set of actions to automatically correct a particular type of error. Additionally, this tool allows users to visualize and compare the original and modified tracings, also providing a 3D mesh that approximates the neuronal membrane. The approximation of this mesh is computed and recomputed on-the-fly, reflecting any instantaneous changes during the tracing process. Moreover, NeuroEditor can be easily extended by users, who can program their own algorithms in Python and run them within the tool. Last, this paper includes an example showing how users can easily define a customized workflow by applying a sequence of editing operations. The edited morphology can then be stored, together with the corresponding 3D mesh that approximates the neuronal membrane
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