A Scalable Correlator Architecture Based on Modular FPGA Hardware, Reuseable Gateware, and Data Packetization

A new generation of radio telescopes is achieving unprecedented levels of sensitivity and resolution, as well as increased agility and field-of-view, by employing high-performance digital signal processing hardware to phase and correlate large numbers of antennas. The computational demands of these imaging systems scale in proportion to BMN^2, where B is the signal bandwidth, M is the number of independent beams, and N is the number of antennas. The specifications of many new arrays lead to demands in excess of tens of PetaOps per second. To meet this challenge, we have developed a general purpose correlator architecture using standard 10-Gbit Ethernet switches to pass data between flexible hardware modules containing Field Programmable Gate Array (FPGA) chips. These chips are programmed using open-source signal processing libraries we have developed to be flexible, scalable, and chip-independent. This work reduces the time and cost of implementing a wide range of signal processing systems, with correlators foremost among them,and facilitates upgrading to new generations of processing technology. We present several correlator deployments, including a 16-antenna, 200-MHz bandwidth, 4-bit, full Stokes parameter application deployed on the Precision Array for Probing the Epoch of Reionization.Comment: Accepted to Publications of the Astronomy Society of the Pacific. 31 pages. v2: corrected typo, v3: corrected Fig. 1

Effectiveness of cognitive-behavioral theraphy in the treatment of Iranian male drug addicts at a state rehabilitation center

Introduction: The present study aimed at examining the effectiveness of cognitive-behavioral therapy (CBT) group intervention on measures of self-efficacy and level of relapse for abstinence among Iranian male drug addicts. Methods: An experimental research design was adopted in the current study in which the participants consisted of 75 male drug addicts who were consecutively admitted as outpatients at a state rehabilitation center. They were randomly allocated to experimental (N=37) and control (N=38) groups. They completed the Iranian version of Drug Taking Confidence Questionnaire (DTCQ-IV) and took urine test as pre-test and post-test. The CBT group intervention was conducted at 12 sessions, one session per week. It was hypothesized that there were significant differences between the experimental and control groups regarding self-efficacy and level of relapse. Result: The results of ANCOVA showed there were significant differences in pleasant emotion and testing control between the two groups on measures of self-efficacy. The results of McNemar test indicated level of relapse in the experimental group significantly declined from pre-test to post-test. Furthermore, using Chi-square analysis, a significant difference (with a moderate effect size) was found in the levels of relapse. Conclusion: The present study provides strong support for CBT group intervention as an effective treatment for Iranian male drug addicts. Therefore, CBT group intervention can be considered as a practical approach in the treatment of people with SUDs

Graduate entry to medicine in Iran

<p>Abstract</p> <p>Backgrounds</p> <p>In Iran medical students are selected from high school graduates via a very competitive national university entrance exam. New proposals have been seriously considered for admitting students from those with bachelor degrees. We assessed the opinions of different stakeholders on the current situation of admission into medicine in Iran, and their views on positive and negative aspects of admitting graduates into medicine.</p> <p>Methods</p> <p>We conducted five focus group discussions and seven in-depth interviews with stakeholders including medical students, science students, university professors of basic sciences, medical education experts, and policy makers. Main themes were identified from the data and analyzed using content analysis approach.</p> <p>Results</p> <p>Medical students believed "graduate admission" may lead to a more informed choice of medicine. They thought it could result in admission of students with lower levels of academic aptitude. The science students were in favor of "graduate admission". The education experts and the professors of basic science all mentioned the shortcomings of the current system of admission and considered "graduate admission" as an appropriate opportunity for correcting some of the shortcomings. The policy makers pointed out the potential positive influences of "graduate admission" on strengthening basic science research. They thought, however, that "graduate admission" may result in lengthening the overall duration of medical education, which is already long in Iran (over 7 years). On the whole, the participants thought that "graduate admission" is a step in the right direction for improving quality of medical education.</p> <p>Conclusion</p> <p>"Graduate admission" has the potential to correct some of shortcomings of medical education. Unlike other countries where "graduate admission" is used mainly to admit students who are mentally mature, in Iran the main objective seems to be strengthening basic sciences.</p

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Finite element modelling of stress concentrations in a reinforced concrete offshore structure

This research describes the finite element modelling of a hybrid supporting tower for an offshore aerogenerator. The hybrid structure consisting of a steel tower mounted on a concrete tripod offers the best compromise between minimum weight and maximum stability. This combination also provides good durability and ease of construction. Earlier studies showed most economic geometry for the tripod support to be a small platform on which the steel tower can be mounted, with legs inclined at about 60o founded at positions determined by overall stability. The main emphasis has been to explore the areas of high stress concentrations which were anticipated to be at the concrete tripod joints. The research, therefore, concentrated initially on the overall modelling of the entire structure. Overall analysis has been carried out under both STATIC and DYNAMIC conditions. Every part of the aerogenerator, including the soil-structure interaction and various structural components were included in the overall model. The overall analysis was subsequently used to model the tripod joints in more detail. Detailed modelling of the joints provided an insight to better understanding of local stress development within the tripod joints. Close resemblance between the actual structure and the F.E. model proved to be crucial during the analysis. Soil-structure interactions were represented in the overall model by means of springs and dashpots. The stiffness of the springs was determined from a separate F.E. modelling of pile-soil medium. A guideline is established to show that the ratio of the number of master degrees of freedom to the active degrees of freedom in the overall model should not be less than a threshold which is different for modal analysis and forced vibration analysis. It is demonstrated that the use of automatic master degrees of freedom selection procedure seriously undermines the accuracy of the local stress analysis in the numerical models. Standard practice in applying finite element analysis to such a hybrid structure has been shown to give good predictions of static and dynamic response, but to underestimate seriously the stresses developed. Response to overall analysis was used to indicate how local stresses can develop. Local stresses have been shown to exceed those predicted by simpler methods, particularly in the areas of combined shear and bending where columns frame into the platform.</p

Which Mouthwashe is Appropriate for Eliminating Coronaviruses? A Mini Literature Review

Aim and background: Coronaviruses can lead to severe respiratory disease and have a significant fatality rate. Dental professionals are high-risk groups because of too many exposures to patients in dental practice. Various mouthwashes have been used for different goals in dentistry. The aim of this study is to assess the appropriate mouthwash to eliminate coronaviruses for pre-procedural rinsing in dental practice. Materials and methods: Electronic databases: PubMed, Scopus, and MEDLINE searched systematically. 5 different keyword combinations used based on MeSH (Medical Subject Headings) database. The search language and time period were English and 1990 to 2020, respectively. Results: Finally, 4 studies included in this review. According to the studies substances that were tested against coronaviruses as a mouthwash were Povidone-iodine (PVP-I) and Chlorhexidine (CHX). 3 studies indicated that PVP-I is a promising substance to eliminate coronaviruses such as SARS-CoV, MERS-CoV and also, influenza virus A (H1N1) and rotavirus. Virucidal effect of CHX against coronaviruses was insufficient. Conclusion: PVP-I gargle/mouthwash is the only approved mouthwash for pre-procedural rinsing in dental practice to eliminate coronaviruses according to the available literature

Conservative Management of Colonoscopic Perforation: A Case Report

Colonoscopy is widely used for the diagnosis, treatment and a follow up of colorectal diseases. Perforation of the large bowel during elective colonoscopy is rare but serious life threatening complication. We report a 51-year-old woman who experienced recto sigmoid perforation during diagnostic colonoscopy. During 8 days of total hospitalization, she spent 3 days in ICU with gastrointestinal rest. The patient was hydrated and took intravenous antibiotics. In take-output and temperature were closely monitored. Serial abdominal examinations were performed to rule out peritonitis. After transferring to surgery ward in the day 4, liquid diet started slowly, and she was ambulated. At the day 8, she was discharged with the good clinical condition. Conservative management of the patients with early diagnosis of perforation and no signs and symptoms of peritonitis or sepsis could be the modality of choice