Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved

Nutrients and antioxidant properties of red, yellow and white onions (Allium cepa L) in Ibadan, Oyo State, Nigeria

Background: Onions is the most widely consumed vegetable worldwide and is a rich source of phytochemicals and antioxidants responsible for fighting free radicals in the body and preventing diseases Objective: The general objective of the study was to analyze and compare the nutrient and antioxidant properties of red, yellow and white onions in Oyo state, Nigeria. Materials and Methods: The research design was experimental. Samples were analyzed chemically according to the official method of analysis described by the Association of Official Analytical Chemist (AOAC). All analysis was carried out in triplicate. Data was analyzed using IBM SPSS statistics version 20. ANOVA was used to compare different variables together. Results: The protein content was same in red and white onions. The crude fibre for red onions was 1.1 ±0.12, yellow onions 1.4±0.08 and white onions 1.2 ±0.12. White Onions had the highest total ash content (0.8 ±0.08), followed by yellow onions (0.6 ± 0.08) and red onions (0.6 ±0.05). The carbohydrate (by difference) was 12.2 ±0.09 for red onions, 11.1 ±0.22 for yellow onions and 11.4 ±0.36 for white onions. The reducing sugars for red onions was 1.8 ±0.12, yellow onions had 1.1 ±0.08 while white onions contained 1.2 ±0.12. The total sugars for red onions, yellow and white onions were 2.6 ±0.12, 1.7 ±0.12 and 2.2 ±0.12 respectively. The ascorbic acid (mg/100g) content was 15.8 ± 0.79 for red onions, 11.2 ±0.21 for yellow onions and 12.4 ±0.53 for white onions. Quercetin (mg/g) was highest in red onions (0.32 ±0.02), followed by yellow onions (0.24 ±0.01) and then white onions (0.19±0.01).   Conclusion: The nutrients and antioxidant (quercetin and vitamin c) properties were higher in red onions compared to the other varieties (white and yellow) of onions

Discrete Time Analysis of Cognitive Radio Networks with Saturated Source of Secondary Users

Part 1: - PE-CRN 2011 WorkshopInternational audienceThe strategy used for sensing in a cognitive radio network affects the white space that secondary users (SUs) perceive and hence their throughput. For example, let the average time interval between consecutive sensing be fixed as τ. There are several possible ways to achieve this mean value. The SU may sense the channel at equal intervals of length τ or sense it at randomly spaced intervals with mean value τ and guided by, for example, geometric distribution, uniform distribution, etc. In the end the strategy selected does affect the available white space and throughput as well as the resources spent on sensing. In this paper we present a discrete time Markov chain model for cognitive radio network and use it to obtain the efficiency of sensing strategies. The system studied is one in which we have a saturated source of secondary users. These assumptions do not in any ways affect our results

Discrete time analysis of cognitive radio networks with imperfect sensing and saturated source of secondary users

Sensing is one of the most challenging issues in cognitive radio networks. Selection of sensing parameters raises several tradeoffs between spectral efficiency, energy efficiency and interference caused to primary users (PUs). In this paper we provide representative mathematical models that can be used to analyze sensing strategies under a wide range of conditions. The activity of PUs in a licensed channel is modeled as a sequence of busy and idle periods, which are represented as alternating Markov phase renewal processes. The representation of the secondary users (SUs) behavior is also largely general: the duration of transmissions, sensing periods and the intervals between consecutive sensing periods are modeled by phase type distributions, which constitute a very versatile class of distributions. Expressions for several key performance measures in cognitive radio networks are obtained from the analysis of the model. Most notably, we derive the distribution of the length of an effective white space; the distributions of the waiting times until the SU transmits a given amount of data, through several transmission epochs or uninterruptedly; and the goodput when an interrupted SU transmission has to be restarted from the beginning due to the presence of a PU.The research of A. S. Alfa was partially supported by the NSERC (Natural Sciences and Engineering Research Council) of Canada under Grant G00315156. Most of the contribution of V. Pla was done while visiting the University of Manitoba. This visit was supported by the Ministerio de Educacion of Spain under grant PR2011-0055, and by the UPV through the Programa de Apoyo a la Investigacion y Desarrollo (PAID-00-12). The research of the authors from the Universitat Politecnica de Valencia was partially supported by the Ministry of Economy and Competitiveness of Spain under Grant TIN2013-47272-C2-1-R.http://www.sciencedirect.com/science/journal/014036642017-04-30hb2016Electrical, Electronic and Computer Engineerin