Reticulocyte count: a simple test but tricky interpretation!

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Advanced Routing Algorithms for General Purpose Photonic Processors

Cost-effective and programmable photonic-driven solutions like electronic counterparts (FPGAs) can be implemented using waveguide mesh architectures along with tunable couplers for routing to implement general-purpose photonic processors. These processors/ networks are represented using undirected weighted graphs, where weights are included to implement constraints in the routing. Faster automated routing and cycle finding algorithms are crucial for dynamic path allocations in live networks to implement various functionalities using these processors. We propose path and cycle finding algorithms based on bidirectional and depth-first search techniques, considering various performance metrics for each device to optimize the path according to the required metric. Multiple cases of path distribution and implementation of cycles of various sizes have been demonstrated. Various methods to eliminate the non-functioning or malfunctioning units are proposed. The broad applicability of the proposed path-finding algorithm has been demonstrated using the same algorithm to create a list of all the possible input-output combinations in a 4*4 photonic switching network. A comparison of available search algorithms in terms of execution time and complexity has been described

Intra-night optical flux and polarization variability of BL~Lacertae during its 2020 −- 2021 high state

In this work, we report the presence of rapid intra-night optical variations in both -- flux and polarization of the blazar BL Lacertae during its unprecedented 2020--2021 high state of brightness. The object showed significant flux variability and some color changes, but no firmly detectable time delays between the optical bands. The linear polarization was also highly variable in both -- polarization degree and angle (EVPA). The object was observed from several observatories throughout the world, covering in a total of almost 300 hours during 66 nights. Based on our results, we suggest, that the changing Doppler factor of an ensemble of independent emitting regions, travelling along a curved jet that at some point happens to be closely aligned with the line of sight can successfully reproduce our observations during this outburst. This is one of the most extensive variability studies of the optical polarization of a blazar on intra-night timescales.Comment: 23 pages,7 figures, 5 Tables (2 as appendix). Accepted for publication in MNRA

Optical intra-day variability of the blazar S5 0716+714

We present an extensive recent multi-band optical photometric observations of the blazar S5 0716+714 carried out over 53 nights with two telescopes in India, two in Bulgaria, one in Serbia, and one in Egypt during 2019 November -- 2022 December. We collected 1401, 689, 14726, and 165 photometric image frames in B, V, R, and I bands, respectively. We montiored the blazar quasi-simultaneously during 3 nights in B, V, R, and I bands; 4 nights in B, V, and R; 2 nights in V, R, and I; 5 nights in B and R; and 2 nights in V and R bands. We also took 37 nights of data only in R band. Single band data are used to study intraday flux variability and two or more bands quasi-simultaneous observations allow us to search for colour variation in the source. We employ the power-enhanced F-test and the nested ANOVA test to search for genuine flux and color variations in the light curves of the blazar on intraday timescales. Out of 12, 11, 53, and 5 nights observations, intraday variations with amplitudes between ~3% and ~20% are detected in 9, 8, 31 and 3 nights in B, V, R, and I bands, respectively, corresponding to duty cycles of 75%, 73%, 58% and 60%. These duty cycles are lower than those typically measured at earlier times. On these timescales color variations with both bluer-when-brighter and redder-when-brighter are seen, though nights with no measurable colour variation are also present. We briefly discuss possible explanations for this observed intraday variability.Comment: 19 pages, 5 figures, 4 tables, Accepted for Publication in MNRA

Lead-Free Halide Perovskite Materials and Optoelectronic Devices: Progress and Prospective

Halide perovskites, in the form of thin films and colloidal nanocrystals, have recently taken semiconductor optoelectronics research by storm, and have emerged as promising candidates for high-performance solar cells, light-emitting diodes (LEDs), lasers, photodetectors, and radiation detectors. The impressive optical and optoelectronic properties, along with the rapid increase in efficiencies of solar cells and LEDs, have greatly attracted researchers across many disciplines. However, most advances made so far in terms of preparation (colloidal nanocrystals and thin films), and the devices with highest efficiencies are based on Pb-based halide perovskites, which have raised concerns over their commercialization due to the toxicity of Pb. This has triggered the search for lower-toxicity Pb-free halide perovskites and has led to significant progress in the last few years. In this roadmap review, researchers of different expertise have joined together to summarize the latest progress, outstanding challenges, and future directions of Pb-free halide perovskite thin films and nanocrystals, regarding their synthesis, optical spectroscopy, and optoelectronic devices, to guide the researchers currently working in this area as well as those that will join the field in the future.I.L.-F., D.V., C.-Y.W., S.S., T.O., Y.-T.H., K.S., Y.L., V.S.C., J.Z., L.D.T., and D.G. contributed equally to this work. L.P. acknowledges the support from the Spanish Ministerio de Ciencia e Innovación through the Ramón y Cajal grant (RYC2018-026103-I) and the Spanish State Research Agency (Grant No. PID2020-117371RA-I00; TED2021-131628A-100), as well as the grant from the Xunta de Galicia (ED431F2021/05). C.-Y.W. acknowledges the financial support from Alexander von Humboldt Foundation. K.S. acknowledges the financial support from China Scholarship Council (CSC), and P.M.-B. acknowledges support from Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC 2089/1–390776260 (e-conversion). V.B. and T.O. acknowledge the MEXT JSPS Grants 20J00974, 21K14580, and 23H01781. H.Z acknowledges the financial supported by NSFC (62222405, 52131304), the Natural Science Foundation of Jiangsu Province (BK20220142), the Fundamental Research Funds for the Central Universities (30922010713), and NSFC-RGC (62261160392). H.-T.S. acknowledges the financial support from JSPS KAKENHI (21H01743). Y.-T.H and R.L.Z.H. would like to thank the Engineering and Physical Sciences Research Council (EPSRC) for funding (no. EP/V014498/2). R.L.Z.H. also thanks the Royal Academy of Engineering through the Research Fellowships scheme (no. RF∖201718∖17101). D.V. and E.D. acknowledge financial support from the Research Foundation – Flanders through an FWO doctoral fellowship to D.V. (FWO Grant Number 1S45223N) and the KU Leuven Internal Funds (Grant Numbers STG/21/010, C14/23/090, and CELSA/23/018). T.D. acknowledges the Department of Science and Technology (DST) and the Science and Engineering Research Board (SERB) for the Ramanujan Fellowship Award (RJF/2021/000125). I.M.-S. acknowledges Ministry of Science and Innovation of Spain under Step-Up (TED2021-131600B-C31) project and by Generalitat Valenciana under Print-P (MFA/2022/020) project. V.S.C., I.M.-S. and J.P.M.-P acknowledges the support of the Horizon 2020 research and innovation program through the DROP-IT project (grant agreement no. 862656)

Estimates of precipitable water vapour from GPS data over the Indian subcontinent

Water vapour plays a dominant role in the high-energy thermodynamics of the atmosphere, notably, the genesis of storm systems. However, its distribution is difficult to resolve by conventional means, since water vapour exhibits very high spatial and temporal variability. The growing networks of continuously operating GPS systems, however, offer the possibility of estimating the integrated water vapour (IWV) or, equivalently precipitable water vapour (PW). These estimates constitute critical inputs in operational weather forecasting and fundamental research to model atmospheric storm systems, atmospheric chemistry, and the hydrological cycle. This paper presents the results of IWV estimates from GPS data from continuously operating GPS stations established by C-MMACS at Bangalore, Kodaikanal, Hanle and Shillong over the 3-year period (2001-2003). These are the first results of such an endeavor, towards the study of PW at four different geographical locations in the Indian subcontinent