Quantum key distribution using a triggered quantum dot source emitting near 1.3 microns

We report the distribution of a cryptographic key, secure from photon number splitting attacks, over 35 km of optical fiber using single photons from an InAs quantum dot emitting ~1.3 microns in a pillar microcavity. Using below GaAs-bandgap optical excitation, we demonstrate suppression of multiphoton emission to 10% of the Poissonian level without detector dark count subtraction. The source is incorporated into a phase encoded interferometric scheme implementing the BB84 protocol for key distribution over standard telecommunication optical fiber. We show a transmission distance advantage over that possible with (length-optimized) uniform intensity weak coherent pulses at 1310 nm in the same system.Comment: 4 pages, 4 figure

Heun Functions and the energy spectrum of a charged particle on a sphere under magnetic field and Coulomb force

We study the competitive action of magnetic field, Coulomb repulsion and space curvature on the motion of a charged particle. The three types of interaction are characterized by three basic lengths: l_{B} the magnetic length, l_{0} the Bohr radius and R the radius of the sphere. The energy spectrum of the particle is found by solving a Schr\"odinger equation of the Heun type, using the technique of continued fractions. It displays a rich set of functioning regimes where ratios \frac{R}{l_{B}} and \frac{R}{l_{0}} take definite values.Comment: 12 pages, 5 figures, accepted to JOPA, november 200

Coronavirus infection (COVID-19): ocular manifestations. clinical case

The article describes a clinical case of keratouveitis with hypertension in a patient with COVID-19 coronavirus infection.В статье рассмотрен клинический случай развития кератоувеита с гипертензией у пациента на фоне коронавирусной инфекцией COVID-1

A global agenda for advancing freshwater biodiversity research

This manuscript is a contribution of the Alliance for Freshwater Life (www.allianceforfreshwaterlife.org). We thank Nick Bond, Lisa Bossenbroek, Lekima Copeland, Dean Jacobsen, Maria Cecilia Londo?o, David Lopez, Jaime Ricardo Garcia Marquez, Ketlhatlogile Mosepele, Nunia Thomas-Moko, Qiwei Wei and the authors of Living Waters: A Research Agenda for the Biodiversity of Inland and Coastal Waters for their contributions. We also thank Peter Thrall, Ian Harrison and two anonymous referees for their valuable comments that helped improve the manuscript. Open access funding enabled and organised by Projekt DEAL

A Critical Review on the Structural Health Monitoring Methods of the Composite Wind Turbine Blades

With increasing turbine size, monitoring of blades becomes increasingly im-portant, in order to prevent catastrophic damages and unnecessary mainte-nance, minimize the downtime and labor cost and improving the safety is-sues and reliability. The present work provides a review and classification of various structural health monitoring (SHM) methods as strain measurement utilizing optical fiber sensors and Fiber Bragg Gratings (FBG’s), active/ pas-sive acoustic emission method, vibration‒based method, thermal imaging method and ultrasonic methods, based on the recent investigations and prom-ising novel techniques. Since accuracy, comprehensiveness and cost-effectiveness are the fundamental parameters in selecting the SHM method, a systematically summarized investigation encompassing methods capabilities/ limitations and sensors types, is needed. Furthermore, the damages which are included in the present work are fiber breakage, matrix cracking, delamina-tion, fiber debonding, crack opening at leading/ trailing edge and ice accre-tion. Taking into account the types of the sensors relevant to different SHM methods, the advantages/ capabilities and disadvantages/ limitations of repre-sented methods are nominated and analyzed

Overview of the TCV tokamak experimental programme

The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T (e)/T (i) similar to 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with \u27small\u27 (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations

Electronic properties and phase transitions in low-dimensional semiconductors

We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X = Se, S, Te) compounds. These chalcogenides belong to a family of the low-dimensional semiconductors possessing chain or layered structure. They are of significant interest because of their highly anisotropic properties, semi- and photoconductivity, non-linear effects in their I-V characteristics (including a region of negative differential resistance), switching and memory effects, second harmonic optical generation, relaxor behavior and potential applications for optoelectronic devices. We review the crystal structure of TlX and TlMX2 compounds, their transport properties under ambient conditions, experimental and theoretical studies of the electronic structure, transport properties and semiconductor-metal phase transitions under high pressure, and sequences of temperature-induced structural phase transitions with intermediate incommensurate states. Electronic nature of the ferroelectric phase transitions in the above-mentioned compounds, as well as relaxor behavior, nanodomains and possible occurrence of quantum dots in doped and irradiated crystals is discussed.Comment: 70 pages, 38 figure

Сопоставление режимов лечения больных первичной открытоугольной глаукомой с характеристиками прогрессирования заболевания. Часть 2. Эффективность инициальных режимов гипотензивного лечения

PURPOSE: To evaluate the efficacy of initial hypotensive treatment strategies in patients with different stages of primary open-angle glaucoma in order to predict glaucoma progression or lack thereof.METHODS: This combined analytical scientific and clinical multicenter study was conducted between January and April 2017. A total of 136 participants (237 eyes) from 30 academic referral centers from 6 (six) countries (Belarus, Kazakhstan, Kyrgyzstan, Moldova, Russia, Uzbekistan) — 52 (38.2%) males and 84 (61.8%) females — were included into the study. Glaucoma anamnesis and all treatment regimens were evaluated retrospectively. The study of treatment regimens included the assessment of the effectiveness of topical medication, laser and surgical treatment. Four (4) successive regimen changes were analyzed, each of them with no less than three (3) months duration.RESULTS: The research team has established that the quantity of treatment regimens rises with each next regimen change: from 14 regimens at baseline to 30 regimens at the third adjustment. Prostaglandin analogues (PGA) and beta-blockers (BB) monotherapy were used as baseline first-choice therapy in 37.6% and 21.5% of cases respectively (66.2% in total). Fixed or unfixed combinations with PGA and BB were preferred in 16.5% of cases, BB and carbonic anhydrase inhibitors (CAI) combination — in 8.4% of cases.The combination therapy with CAI at the start has achieved the most prominent reduction of intraocular pressure (IOP) (till 33.9%). The first choice monotherapy with BB or PGA led to a more effective IOP reduction compared to fixed or unfixed combinations of these drugs: BB reduced the IOP level by 20.0% from baseline, PGA — by 23.1%, their combination — by 19.2%. We have established an intensive use of combination therapy, starting with the 2nd regimen — 71.3%. The laser and surgical treatment was used as initial treatment in 0.8% and 2.1% respectively and achieved 26.7% and 46.0% prevalence respectively by the a final regimen.We achieved the most prominent IOP reduction (by 37.1%) in regimens No 3 and No 4 that included trabeculectomy.CONCLUSION: The results show that the tactics of managing patients with newly diagnosed glaucoma is changing in favor of prescribing first-choice monotherapy medicines — PGA. The choice of therapy tactics for patients with moderate and advanced glaucoma remains irrational: laser and surgical treatment becomes relevant only in regimens No 3 and No 4, 3-4 years after the diagnosis of the disease.ЦЕЛЬ. Установить эффективность инициальных (стартовых) режимов гипотензивного лечения у пациентов с различными стадиями первичной открытоугольной глаукомы (ПОУГ) с определением их роли в прогрессировании заболевания.МЕТОДЫ. В комбинированное аналитическое научноклиническое многоцентровое исследование, проведенное в период с января по апрель 2017 года на 30 научноклинических базах 6 (шести) стран (Беларусь, Казахстан, Кыргызстан, Молдова, Россия, Узбекистан), были включены данные 136 человек (237 глаз; мужчин — 52 (38,2%), женщин — 84 (61,8%)). Проведен ретроспективный анализ данных анамнеза заболевания и режимов проводимого лечения. Изучение режимов лечения подразумевало определение эффективности медикаментозной терапии, лазерного и хирургического лечения. Всего анализу было подвергнуто 4 (четыре) последовательных смены схем лечения в течение документально установленного анамнеза заболевания продолжительностью не менее чем 3 (три) месяца от момента первого назначения.РЕЗУЛЬТАТЫ. Установлено увеличение количества используемых режимов по мере увеличения порядкового номера режима: от 14 комбинаций «на старте» лечения до 30 вариантов в режиме № 3. На старте лечения преобладала монотерапия (66,2%): предпочтение отдавалось аналогам простагландинов (ПГ) (37,6%) и бетаадреноблокаторам (ББ) (21,5%). Среди фиксированных и нефиксированных комбинаций превалировали препараты, включающие ББ и ПГ (16,5%) и ББ с ингибиторами карбоангидразы (ИКА) (8,4%). Максимальная гипотензивная эффективность (снижение офтальмотонуса на 33,9% от исходного) инициального режима была достигнута в группах, где использовались комбинации препаратов, содержащие ИКА. Применение ББ и ПГ в качестве монотерапии продемонстрировало более выраженное снижение уровня офтальмотонуса, по сравнению с комбинациями этих препаратов: монотерапия ББ снизила его на 20,0% от исходного, ПГ — на 23,1%, в то время как инстилляции этих препаратов в виде фиксированной или нефиксированной комбинации в среднем снизили уровень внутриглазного давления (ВГД) только на 19,2%. Активное применение схем комбинированной терапии установлено, начиная с режима № 2, оно составило 71,3% от всех назначений. Доля лазерных и хирургических методов на старте составила 0,8 и 2,1% соответственно, прогнозируемо увеличившись к финалу — до 26,7 и 46,0% соответственно. Максимальная гипотензивная эффективность (снижение уровня офтальмотонуса на 37,1% от исходного) в режимах № 3 и № 4 была достигнута при применении синустрабекулэктомии.ЗАКЛЮЧЕНИЕ. Полученные данные показывают, что тактика ведения пациентов с впервые выявленной глаукомой меняется в пользу назначения препаратов «первой линии терапии» — аналогов простагландинов.Тактика выбора терапии для пациентов с развитой и далеко зашедшей стадиями глаукомы остается нерациональной: лазерное и хирургическое лечение становится актуальным только в режимах № 3 и № 4, спустя 3-4 года от момента диагностирования заболевания