Fixed points on band structures of non-Hermitian models and the resulting extended states in the bandgap and ideal superluminal tunneling

PT symmetry in non-Hermitian electronic models has drawn much attention over the past decade mainly because it guarantees that the band structures calculated under open boundary conditions be the same as those calculated under periodic boundary conditions. PT symmetry in electromagnetic (EM) models, which are usually borrowed from electronic models, has also been of immense interest mainly because it leads to 'exceptional' parameter values below which non-Hermitian operators have real eigenvalues, although PT symmetry is not the sole symmetry which allows such exceptional parameter values. In this article, we examine 1-dimensional PT-symmetric non-Hermitian EM models to introduce novel concepts and phenomena. We introduce the band-structure concept of 'fixed points', which leads to 'bidirectional' reflection zeros in the corresponding finite structures, contrary to a common belief about the EM structures with PT symmetry (and without P and T symmetries). Some of the fixed points manifest themselves as what we name 'extended states in the bandgap' on the band structure while some other fixed points are the 'turning points' of the band structure. The extended states in the band gap are in fact the dual of the well-known 'bound stated in the continuum' while the turning points allow us to observe 'ideal' superluminal tunneling in the corresponding finite structures. By 'ideal' superluminal tunneling we mean the case where not only the transmission coefficient has an almost uniform phase over a broad bandwidth but also the magnitudes of the transmission and reflection coefficients are almost equal to unity and zero, respectively, over the bandwidth

Determination of the design parameters for making urban wastewater plants in cold regions of Iran

زمینه و هدف: تعیین مشخصات کمی و کیفی فاضلاب خام ورودی به تصفیه خانه ها یکی از ارکان اصلی طراحی صحیح تصفیه خانه های فاضلاب به حساب می آید. این مطالعه با هدف تعیین پارامترهای طراحی تصفیه خانه های فاضلاب شهری برای مناطق سردسیر کشور انجام شد. روش بررسی: در این مطالعه توصیفی- تحلیلی سه تصفیه خانه فاضلاب شهرکرد، بروجن و فارسان واقع در استان چهارمحال و بختیاری به عنوان پایلوت در منطقه سردسیر انتخاب و مشخصات کمی و کیفی فاضلاب ورودی به آنها در یک دوره یکساله (سال 1386) بررسی گردید. علاوه بر اندازه گیری پیوسته دبی فاضلاب ورودی به تصفیه خانه، دما، pH ورودی، غلظت اکسیژن خواهی شیمیایی (COD)، غلظت اکسیژن خواهی بیوشیمیایی پنج روزه (BOD)، مواد معلق (TSS)، مواد معلق فرار (VSS)، نیتــــروژن کجلدال (TKN)، فسفر فسفاتی، در نمونه های مرکب 24 ساعته متناسب با دبی، اندازه گیری شد.داده ها به کمک آزمون های آماری t و ANOVA تجزیه و تحلیل شدند. یافته ها: میانگین سرانه پارامترهای مورد تحقیق در این مطالعه بر حسب گرم در روز به ازای هر نفر برای BOD5 معادل 41، COD معادل 60، TSS معادل 65، VSS معادل 47، TKN معادل 3/8 و برای فسفات معادل 93/0 و متوسط تولید فاضلاب، 177 لیتر به ازای هر نفر در روز و ضریب حداکثر و حداقل دبی فاضلاب به ترتیب 76/1 و 29/0 بدست آمد. مقایسه نتایج پارامترهای سرانه مورد نظر در سه تصفیه خانه اختلاف معنی داری بین پارامترهای BOD5، COD، نیتروژن کجدال و فسفر وجود نداشت ولی میزان TSS، VSS در تصفیه خانه های مورد مطالعه بیشتر بود (05/0

Boundary condition nomenclature confusion in groundwater flow modelling

© 2019 John Wiley & Sons, Inc. This author accepted manuscript is made available following 12 month embargo from date of publication (April 2019) in accordance with the publisher’s archiving policyTo solve the partial differential equations of groundwater flow, the information about head (h) and/or head gradient (∇h) must be specified along the boundaries of a model domain. The descriptors of different boundary condition (BC) types are drawn from founding mathematicians mainly of the 19th century (Cheng and Cheng 2005). Mathematically, there are five different BC types, including: Dirichlet (Type 1), Neumann (Type 2), Robin (Type 3), Cauchy and Mixed (Liu 2018). These names are sometimes used in communicating the BCs of groundwater flow models, and therefore, correct association between nomenclature and the mathematical form of BCs is important for properly communicating model characteristics

Sustaining the National Spinal Cord Injury Registry of Iran (NSCIR-IR) in a Regional Center: Challenges and Solutions

Background: The National Traumatic Spinal Cord Injury Registry in Iran (NSCIR-IR), was implemented initially in three hospitals as a pilot phase from 11 Oct 2015 to 19 Jun 2016 and has been active in eight centers from 19 Jun 2016. Poursina Hospital, a trauma care referral center in Rasht, Guilan Province of Iran is one of the registry sites, and has been involved in registering eligible patients since 1 Jan 2016. This study aimed to identify the challenges and solutions for sustaining the NSCIR-IR in a regional center. Methods: This was a mixed-methods study. For the quantitative analysis, a retrospective observational design was used to measure case capture or case identification rate, mapping cases in the registry against those eligible for registry inclusion amongst the register of hospital admissions. For the qualitative component, data was collected using focus group discussions and semi-structured interviews, followed by thematic analysis. Results: From 19 Jun 2016 to 24 Jan 2018, the proportion of case capture (case identification rate) was 17%. The median time between case identification and data entry to the system was 30.5 d (range: 2 to 193 d). Thematic analysis identified a lack of trained human resources as the most important cause of low case identification rate and delay in data completion. Conclusion: Recruitment and education to increase trained human resources are needed to improve case capture, the timeliness of data input and registry sustainability in a regional participating site

Cyclosporin A attenuating morphine tolerance through inhibiting NO/ERK signaling pathway in human glioblastoma cell line

Cyclosporin A (CsA) is known to have an immunosuppressive action. However, it is also attracting attention due to its effects on the nervous system, such as inhibiting the development and expression of morphine-induced tolerance and dependence through unknown mechanisms. It has been shown that CsA modulates the nitric oxide (NO) synthesis and extracellular signal-regulated kinases (ERK) activation, which are potentially involved in signaling pathways in morphine-induced tolerance in cellular models. Therefore, the current study was designed to evaluate the modulatory role of CsA on the MOR tolerance, by targeting the downstream signaling pathway of NO and ERK using an in vitro model. For this purpose, T98G cells were pretreated with CsA, calcineurin autoinhibitory peptide (CAIP), and NG-nitro-l-arginine methyl ester (L-NAME) 30 min before 18 h exposure to MOR. Then, we analyzed the intracellular cyclic adenosine monophosphate (cAMP) levels and also the expression of phosphorylated ERK and nitric oxide synthase (nNOS) proteins. Our results showed that CsA (1 nM, 10 nM, and 100 nM) and CAIP (50 μM) have significantly reduced cAMP and nitrite levels as compared to MOR-treated (2.5 μM) T98G cells. This clearly revealed the attenuation of MOR tolerance by CsA. The expression of nNOS and p-ERK proteins were down-regulated when the T98G cells were pretreated with CsA (1 nM, 10 nM, and 100 nM), CAIP (50 μM), and L-NAME (0.1 mM) as compared to MOR. In conclusion, the CsA pretreatment had a modulatory role in MOR-induced tolerance, which was possibly mediated through NO/ERK signaling pathway

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe