20-inch photomultiplier tube timing study for JUNO

Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator neutrino detector now under construction at Jiangmen, Guangdong, China for determination of neutrino mass ordering with 3% energy resolution at 1 MeV, a precise measurement of neutrino oscillation parameters, and other neutrino physics. The central detector is made up of a 35.4-meter diameter acrylic sphere which contains 20 kton of liquid scintillator and is surrounded by about 18k 20-inch photomultiplier tubes (PMTs). The PMTs performance is one of the JUNO’s key successes to reach the high resolution goal. In this study, the PMT characteristic and its timing related responses were determined via the PMT generated signals, extracted from the PMT in a scanning station system. About 2,400 of micro-channel plate PMTs (MCP-PMTs) and dynode PMTs were analyzed for their responses with LED source such as rise time, fall time, transit time spread (TTS), gain, etc., which relate to photon incident on different positions of PMT’s glass surface. Furthermore, we also observed the fluctuation of PMT performance under magnetic field which can decrease the PMT photon detection efficiency (PDE).

Homogeneity of the photocathode in the Hamamatsu Photomultiplier Tube

It is common practice to test the optical properties of photomultiplier tubes (PMTs) by illuminating the entire photocathode region from the front at once and measuring the average performance. However, for optimal utilisation of the PMT performance in experiments, especially in the single-photon region, it is essential to also know the systematic variations across the photocathode, which requires measurements with focused light sources that illuminate only small regions of the PMT. We present a detailed uniformity characterisation of the gain, transit time, transit time spread, and pulse shape of the 80 mm Hamamatsu R15458-02 PMT. We find that the parameters exhibit asymmetry along one axis, likely caused by the position and geometry of the dynode system. For all parameters except the transit time, the observed variations are small given the intrinsic variation of the parameters. For positions with shifted transit time we observe on average underamplified pulses which can potentially be exploited to improve the pulse reconstruction.

Field Emergence Affected by Zea Mays L. Cultivars and Seed Soaking in Acids of Ascorbic, Citric and Humic

A field experiment was carried out during the spring season 2019 and 2020 to obtain a fast, uniform, and high field emergence ratio of maize seeds under a wide range of environmental conditions. Randomize complete block design in the split-plot arrangement was used with three replications. The first factor in the main plots was cultivars (5018, Baghdad3 and Sumer). The second factor in the sub-plots was seeds soaking with ascorbic and citric acids (100 mg L−1) each and humic (1 ml L−1) in addition to control treatment (seeds soaking with distilled water only). Results showed the superiority of soaking with humic acid significantly, as means of characteristics of field emergence in both seasons, respectively, were as follows: Last day of field emergence (12.4 and 12.6 days), time spread of field emergence (4.4 and 4.6 days), emergence at first and final counts (62.4 and 34.4 %) and (95.8 and 88.0 %), daily emergence rate (8.0 and 7.3 % day−1), mean field emergence time (8.7 and 9.3 days), emergence index rate (11.1 and 9.7 % day−1), velocity coefficient of field emergence (11.4 and 10.8) and emergence index (407.6 and 333.3). Cultivars didn’t differentiate among themselves, with the effect of seeds soaking in most traits. It can be concluded that seeds soaking with humic acid improved characteristics of emergence and seedlings, so it can be recommended to soaking maize seeds with humic acid at the concentration (1 ml L−1) when planting them in the spring season.

Genomic epidemiology reveals how restriction measures shaped the SARS-CoV-2 epidemic in Brazil

Brazil has experienced some of the highest numbers of COVID-19 infections and deaths globally and made Latin America a pandemic epicenter from May 2021. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of local virus transmission dynamics. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and an adjacent country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed, the absence of effective restriction measures led to the local emergence and international spread of Variants of Concern (VOC) and under monitoring (VUM), including the Gamma (P.1) and Zeta (P.2) variants. In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring and providing a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies.

Seed germination responses to low-level narrow-band light spectra for 14 ornamental plant genotypes

To investigate whether low-level lighting is necessary and which narrow-band light spectra are effective in seeds germination, seeds of 14 genotypes from begonia, echinacea, gerbera, petunia, and vinca were germinated under ultraviolet-B (UVB), blue (B), green (G), red (R), far-red (FR) light, or darkness. Light-emitting diode (LED) fixtures provided all spectrum treatments except for UVB, which was provided by a narrow-band fluorescent light. The photon flux density at seed level was ≈18 µmol m-2 s-1 for B, G, R, and FR, and 0.4 µmol m-2 s-1 for UVB. Based on daily germination observations, final germination percentage, germination onset time, germination time spread, and germination speed were compared among different spectrum treatments for each of the plant genotypes. There were no promotive effects on final germination percentage, germination onset time, and germination time spread under the narrow-band lights compared to darkness. For all plant genotypes, B had a similar effect as darkness on seed germination. FR inhibited seed germination relative to darkness by reducing final germination percentage by 31–88%, delaying germination onset time by 30–40%, and decreasing germination speed by 11–48% in some genotypes. Under R, G, and UVB compared to darkness, germination speed was promoted for begonia ‘Apricot Shade’, a light-requiring genotype, and inhibited for vinca ‘Burgundy’, a light-inhibited genotype. Therefore, lighting at low levels used in our study is unnecessary for seed germination of the tested species except light-requiring genotypes, where R, G, and UVB are the most promotive among the tested narrow-band lights.

“Zinc Boys” and “Chernobyl Man” in Svetlana Alexievich᾿s Documentary-Artistic Anthropology

The article considers the anthropological content of the documentary and artistic books by Svetlana Alexievich “Zinc boys” (1989) and “Chernobyl prayer” (1986– 2005). “Zinc boys” and “Chernobyl man” are presented in the work as symptomatic socio-psychological phenomena of our time, spread far beyond the historical circumstances risen by them.

Emergence and Spread of B.1.1.7 Lineage in Primary Care and Clinical Impact in the Morbi-Mortality among Hospitalized Patients in Madrid, Spain

In December 2020, UK authorities warned of the rapid spread of a new SARS-CoV-2 variant, belonging to the B.1.1.7 lineage, known as the Alpha variant. This variant is characterized by 17 mutations and 3 deletions. The deletion 69–70 in the spike protein can be detected by commercial platforms, allowing its real-time spread to be known. From the last days of December 2020 and over 4 months, all respiratory samples with a positive result for SARS-CoV-2 from patients treated in primary care and the emergency department were screened to detect this variant based on the strategy S gene target failure (SGTF). The first cases were detected during week 53 (2020) and reached >90% of all cases during weeks 15–16 (2021). During this period, the B.1.1.7/SGTF variant spread at a rapid and constant replacement rate of around 30–36%. The probability of intensive care unit admission was twice higher among patients infected by the B.1.1.7/SGTF variant, but there were no differences in death rate. During the peak of the third pandemic wave, this variant was not the most prevalent, and it became dominant when this wave was declining. Our results confirm that the B.1.1.7/SGTF variant displaced other SARS-CoV-2 variants in our healthcare area in 4 months. This displacement has led to an increase in the burden of disease.

Biopriming with Seaweed Extract and Microbial-Based Commercial Biostimulants Influences Seed Germination of Five Abelmoschus esculentus Genotypes

Seed germination is a crucial step in plant propagation, as it controls seedling production, stand establishment and ultimately crop yield. Approaches that can promote seed germination of valuable crops remain of great interest globally. The current study evaluated the effect of biostimulant (Kelpak® and plant-growth-promoting rhizobacteria—PGPR) biopriming on the seed germination of five (VI037996, VI046567, VI055421, VI050956, and VI033796) Abelmoschus esculentus genotypes. The germination responses of the bio-primed seeds were measured using six parameters, including final germination percentage (FGP), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), germination rate index (GRI), and time spread of germination (TSG). Biostimulant application significantly affected MGT (1.1–2.2 days), CVG (1.4–5.9), and TSG (1.2–3.0 days). Genotype also significantly influenced the TSG (1–3 days). Significant interaction effect of biostimulant treatment and genotype was evident on the FGP, GI, and GRI of the germinated seeds. The most noteworthy effect was demonstrated by Kelpak® (1:100) applied to genotype VI037996, with significantly improved FGP (82%), GI (238), and GRI (77%/day) when compared to the control. Overall, the current findings suggest the potential stimulatory effect of biostimulants (especially Kelpak®) on the germination of Abelmoschus esculentus seeds. However, this influence was strongly dependent on the type of genotype.

Muon Tracker with Unsegmented Plastic Scintillator Panels

A muon tracker was developed using three polyvinyl toluene scintillator panels instrumented with photomultiplier tubes (PMTs) mounted at the corners. Panels are mounted in parallel on an aluminum frame which allows for simple adjustment of angle, orientation and separation distance between the panels. The responses of all PMTs in the system are digitized simultaneously at sub-nanosecond sample spacing. Software was developed to adjust settings and implement event rejection based on the number of panels that detected a scintillation event within a 400-nanosecond record. The relative responses of the PMTs are used to calculate the position of scintillation events within each panel. The direction of the muons through the system can be tracked using the panel strike order. Methods for triangulation by both time-of-flight (TOF) and PMT magnitude response are reported. The time triangulation method is derived and experimentally demonstrated using parallel cables of differing length. The PMTs used in this experiment are only optimized for amplitude discrimination, not for time spread jitter as would be required to implement TOF methods into the scintillator panels. A Gaussian process regression machine learning tool was implemented to learn the relationship between PMT response features and positions from a calibration dataset. Resolution is analyzed using different numbers of PMTs and low-versus-high PMT sensitivities. Muons traveling in forward and reverse directions through the detector system were counted in all six axis orientations. The muon detector was deployed for 28 days in an underground tunnel and vertical muon counts were recorded.

DAMPAK PEMBELAJARAN DARING DAN PSHYCAL DISTANCING TERHADAP TINGKAT KECEMASAN MAHASISWA KEBIDANAN STIKES MUHAMMADIYAH SIDRAP ERA COVID-19

Covid-19 in a short time spread to almost all countries in the world, including Indonesia. The impact of Covid-19 is very dangerous, in Indonesia taking preventive steps, namely Pshycal distancing is a policy that has an impact on decisions regarding online learning. This policy is to minimize and suppress the spread of Covid-19. Studying online is not easy. Difficulties arise not only in terms of skill in using technology, but by adding a large quota and not having a laptop. This research aims to determine the impact of online learning and Pshycal distancing on the anxiety level of midwifery students. The method used is descriptive with a quantitative approach. The population in this study were the midwifery students of STIKES Muhammadiyah Sidrap. Sampling was done by random sampling. The criteria for the sample were midwifery students who were still active and following online learning. ZSAS research instrument. The research questionnaire uses Google Form through online media. Dianalisi using the Chi-Square test to determine the relationship between the two variables. Data analysis was performed using SPSS Version 24.0. The results of the analysis show that online learning carried out at STIKES Muhammadiyah Sidrap was obtained by students who did not agree with online learning (83.3%) because of obstacles in using learning applications, namely students did not have a quota (47.9%) and difficult Internet networks (41.7%). While students tend to experience severe anxiety (50.0%) and moderate (29%) It can be concluded that there is an effect of online learning and Pshycal distancing on student anxiety. Criticism can appear in various stages of lectures, so it is important for research related to differences in the degree of anxiety of early and late students.