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Background Understanding the characteristics and natural history of novel pathogens is crucial to inform successful control measures. Japan was one of the first affected countries in the COVID-19 pandemic reporting their first case on 14 January 2020. Interventions including airport screening, contact tracing, and cluster investigations were quickly implemented. Here we present insights from the first 3 months of the epidemic in Japan based on detailed case data. Methods We conducted descriptive analyses based on information systematically extracted from individual case reports from 13 January to 31 March 2020 including patient demographics, date of report and symptom onset, symptom progression, travel history, and contact type. We analysed symptom progression and estimated the time-varying reproduction number, Rt, correcting for epidemic growth using an established Bayesian framework. Key delays and the age-specific probability of transmission were estimated using data on exposures and transmission pairs. Results The corrected fitted mean onset-to-reporting delay after the peak was 4 days (standard deviation: ±2 days). Early transmission was driven primarily by returning travellers with Rt peaking at 2.4 (95%CrI:1.6, 3.3) nationally. In the final week of the trusted period, Rt accounting for importations diverged from overall Rt at 1.1 (95% CrI: 1.0, 1.2) compared to 1.5 (95% CrI: 1.3, 1.6) respectively. Household (39.0%) and workplace (11.6%) exposures were the most frequently reported potential source of infection. The estimated probability of transmission was assortative by age. Across all age groups, cases most frequently onset with cough, fever, and fatigue. There were no reported cases of patients

17 pags., 11 figs., 3 tabs., Background: The nucleus Mg32 (N=20 and Z=12) plays a central role in the so-called "island of inversion,"where in the ground states sd-shell neutrons are promoted to the fp-shell orbitals across the shell gap, resulting in the disappearance of the canonical neutron magic number N=20. Purpose: The primary goals of this work are to extend the level scheme of Mg32, provide spin-parity assignments to excited states, and discuss the microscopic structure of each state through comparisons with theoretical calculations. Method: In-beam γ-ray spectroscopy of Mg32 was performed using two direct-reaction probes: one-neutron (two-proton) knockout reactions on Mg33 (Si34). Final-state exclusive cross sections and parallel momentum distributions were extracted from the experimental data and compared with eikonal-based reaction model calculations combined with shell-model overlap functions. Results: Owing to the remarkable selectivity of the one-neutron and two-proton knockout reactions, a significantly updated level scheme for Mg32, which exhibits negative-parity intruder and positive-parity normal states, was constructed. The experimental results were confronted with four different nuclear structure models. Conclusions: In some of these models, different aspects of Mg32 and the transition into the island of inversion are well described. However, unexplained discrepancies remain, and, even with the help of these state-of-The-Art theoretical approaches, the structure of this key nucleus is not yet fully captured., N.K. acknowledges support of the Grant-in-Aid for JSPS Fellows (18J12542) from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan. K.W. acknowledges support from the Ministerio de Ciencia e Innovación (Spain) through the “Ramón y Cajal” program RYC-2017- 22007. A.P. is supported by the Ministerio de Ciencia, Innovación y Universidades (Spain), Grant No. CEX2020- 001007-S funded by MCIN/AEI/10.13039/501100011033 and Grant No. PGC-2018-94583. The SDPF-M calculations were enabled by the CNS-RIKEN joint project for large-scale nuclear structure calculations and were performed mainly on the Oakforest-PACS supercomputer. N.S. acknowledges support from “Priority Issue on post-K computer” (hp190160) and “Program for Promoting Researches on the Supercomputer Fugaku” (JPMXP1020200105, hp200130, and hp210165) by JICFuS and MEXT, Japan. The IMSRG calculations were performed with an allocation of computing resources on Cedar at WestGrid and Compute Canada and on the Oak Cluster at TRIUMF managed by the University of British Columbia, Department of Advanced Research Computing. J.A.T. acknowledges support from the U.K. Science and Technology Facilities Council Grant No. ST/L005743/1. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Nuclear Physics, under Grant No. DE-SC0020451 and by the U.S. National Science Foundation (NSF) under Grant No. PHY-1306297. GRETINA was funded by the U.S. DOE, Office of Science. Operation of the array at NSCL is supported by the U.S. NSF under Cooperative Agreement No. PHY-1102511 (NSCL) and DOE under Grant No. DE-AC02-05CH11231 (LBNL).

Contact tracing, where exposed individuals are followed up to break ongoing transmission chains, is a key pillar of outbreak response for infectious disease outbreaks. Unfortunately, these systems are not fully effective, and infections can still go undetected as people may not remember all their contacts or contacts may not be traced successfully. A large proportion of undetected infections suggests poor contact tracing and surveillance systems, which could be a potential area of improvement for a disease response. In this paper, we present a method for estimating the proportion of infections that are not detected during an outbreak. Our method uses next generation matrices that are parameterized by linked contact tracing data and case line-lists. We validate the method using simulated data from an individual-based model and then investigate two case studies: the proportion of undetected infections in the SARS-CoV-2 outbreak in New Zealand during 2020 and the Ebola epidemic in Guinea during 2014. We estimate that only 5.26% of SARS-CoV-2 infections were not detected in New Zealand during 2020 (95% credible interval: 0.243 – 16.0%) if 80% of contacts were under active surveillance but depending on assumptions about the ratio of contacts not under active surveillance versus contacts under active surveillance 39.0% or 37.7% of Ebola infections were not detected in Guinea (95% credible intervals: 1.69 – 87.0% or 1.70 – 80.9%).

Excited states in $^{56}$Zn were populated following one-neutron removal from a $^{57}$Zn beam impinging on a Be target at intermediate energies in an experiment conducted at the Radioactive Isotope Beam Factory at RIKEN. Three γ rays were observed and tentatively assigned to the 6+→4+→2+→0+ yrast sequence. This turns $^{56}$Zn into the heaviest Tz=−2 nucleus in which excited states are known. The excitation-energy differences between these levels and the isobaric analogue states in the Tz=+2 mirror partner, $^{56}$Fe, are compared with large-scale shell-model calculations considering the full pf valence space and various isospin-breaking contributions. This comparison, together with an analysis of the mirror energy differences in the A=58, Tz=±1 pair $^{58}$Zn and $^{58}$Ni, provides valuable information with respect to the size of the monopole radial and the isovector multipole isospin-breaking terms in the region above doubly-magic $^{56}$Ni.

Situated in the so-called “island of inversion,” the nucleus $^{32}$Mg is considered as an archetypal example of the disappearance of magicity at N=20. We report on high statistics in-beam spectroscopy of $^{32}$Mg with a unique approach, in that two direct reaction probes with different sensitivities to the underlying nuclear structure are employed at the same time. More specifically, states in $^{32}$Mg were populated by knockout reactions starting from $^{33}$Mg and $^{34}$Si, lying inside and outside the island of inversion, respectively. The momentum distributions of the reaction residues and the cross sections leading to the individual final states were confronted with eikonal-based reaction calculations, yielding a significantly updated level scheme for $^{32}$Mg and spin-parity assignments. By fully exploiting observables obtained in this measurement, a variety of structures coexisting in $^{32}$Mg was unraveled. Comparisons with theoretical predictions based on shell-model overlaps allowed for clear discrimination between different structural models, revealing that the complete theoretical description of this key nucleus is yet to be achieved.

The study of 254Es via Coulomb excitation gamma-ray spectroscopy has been performed at the JAEA-Tokai Tandem Laboratory using a 58Ni beam with an energy of 250 MeV. The detector system includes: 4 single-crystal HPGe detectors, 4 LaBr3(Ce) scintillators and 4 Clover type HPGe detectors and 2 CD silicon detectors placed backward and forward to the target for detecting scattered particle. A “safe” Coulomb excitation of 254Es was achieved for the first time to study its excited states. The 254Es gamma-ray spectrum was investigated by gating on the scattered 58Ni particle measured by the CD Si detectors. The gamma spectrum created after gain matching and Doppler shift correction was analyzed. From the gamma spectrum, several new transitions of 254Es were observed and they indicated the rotational band structure. The extracted data could help to extend the 254Es level scheme and determine its quadrupole deformation., 日本物理学会２０２１年秋季大会

ispartof: PHYSICAL REVIEW C vol:104 issue:2 status: published

Reports of early and catastrophic acute structural valve deterioration (SVD) in Trifecta valves (Abbott, St Paul, MN, USA) with multiple leaflet detachment are rare. We encountered two cases of early SVD in Trifecta valves with tears on two leaflets. Both cases presented with acute heart failure because of aortic insufficiency and underwent redo aortic valve replacement; one patient died due to multiple organ failure caused by cardiogenic shock. Durability issues with valves necessitate long-term vigilance in aortic valve replacement patients.

A study of the laser-ionized and mass-separated neutron-deficient isotopes $^{176,177,179}$Au was performed using the Resonance Ionization Laser Ion Source and the Windmill detection setup at ISOLDE, CERN. New and improved data on complex fine-structure α decays of the three isotopes were deduced, providing insight into the low-lying levels in the daughter nuclei $^{172,173,175}$Ir. New information on the properties of β-decay daughter products $^{177,179}$Pt was also obtained. From the first in-source laser spectroscopy measurements of the hyperfine structure in the atomic 267.6-nm transition of 176Au, the nuclear magnetic moments for both high- and low-spin α-decaying states were deduced. Together with the values determined from the additivity relations, they were used to propose the most probable spins and configurations for both states. The α-decay branching ratios were determined as $b_{\alpha}$ $\left (^{176}\textrm{Au}^{ls}\right)=58(5)$% and $b_{\alpha}$ $(^{176} \textrm{Au}^{hs})=29(5)$%.

England has been severely affected by COVID-19. We fitted a model of SARS-CoV-2 transmission in care homes and the community to regional 2020 surveillance data. Only national lockdown brought the reproduction number below 1 consistently; introduced one week earlier in the first wave it could have reduced mortality by 23,300 deaths on average. The mean infection fatality ratio was initially ~1.3% across all regions except London and halved following clinical care improvements. The infection fatality ratio was two-fold lower throughout in London, even when adjusting for demographics. The infection fatality ratio in care homes was 2.5-times that in the elderly in the community. Population-level infection-induced immunity in England is still far from herd immunity, with regional mean cumulative attack rates ranging between 4.4% and 15.8%.

The elastic scattering of the weakly bound radioactive nuclei B8 and Be7 from a Pb208 target was measured for the first time in the energy range around the Coulomb barrier. The data were analyzed using the optical model and the continuum discretized coupled channels (CDCC) formalisms. The reaction cross sections extracted from the optical model fits clearly indicate a remarkably enhanced reaction probability for the very weakly bound B8 (Sp=137.5keV) compared to similar mass nuclei interacting with the same target nucleus. CDCC calculations assuming a He3+He4 cluster model well described the Be7 experimental elastic scattering angular distributions, whereas the use of a Be7+p cluster model of B8 with an inert Be7 core gave a relatively poor description of the corresponding experimental data, suggesting that this model may be too simplistic and the possibility of core excitation should not be ignored.

SARS-CoV-2 infections have been reported in all age groups including infants, children, and adolescents. However, the role of children in the COVID-19 pandemic is still uncertain. This systematic review of early studies synthesises evidence on the susceptibility of children to SARS-CoV-2 infection, the severity and clinical outcomes in children with SARS-CoV-2 infection, and the transmissibility of SARS-CoV-2 by children. A systematic literature review was conducted in PubMed. Reviewers extracted data from relevant, peer-reviewed studies published during the first wave of the SARS-CoV-2 outbreak using a standardised form and assessed quality using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. For studies included in the meta-analysis, we used a random effects model to calculate pooled estimates of the proportion of children considered asymptomatic or in a severe or critical state. We identified 2,775 potential studies of which 128 studies met our inclusion criteria; data were extracted from 99, which were then quality assessed. Finally, 29 studies were considered for the meta-analysis that included information of symptoms and/or severity, these were further assessed based on patient recruitment. Our pooled estimate of the proportion of test positive children who were asymptomatic was 21.1% (95% CI: 14.0 - 28.1%), based on 13 included studies, and the proportion of children with severe or critical symptoms was 3.8% (95% CI: 1.5 - 6.0%), based on 14 included studies. We did not identify any studies designed to assess transmissibility in children and found that susceptibility to infection in children was highly variable across studies. Children’s susceptibility to infection and onward transmissibility relative to adults is still unclear and varied widely between studies. However, it is evident that most children experience clinically mild disease or remain asymptomatically infected. More comprehensive contact-tracing studies combined with serosurveys are needed to quantify children’s transmissibility relative to adults. With children back in schools, testing regimes and study protocols that will allow us to better understand the role of children in this pandemic are critical.

Several SARS-CoV-2 vaccine candidates are now in late-stage trials, with efficacy and safety results expected by the end of 2020. Even under optimistic scenarios for manufacture and delivery, the doses available in 2021 are likely to be limited. Here we identify optimal vaccine allocation strategies within and between countries to maximise health (avert deaths) under constraints on dose supply. We extended an existing mathematical model of SARS-CoV-2 transmission across different country settings to model the public health impact of potential vaccines, using a range of target product profiles developed by the World Health Organization. We show that as supply increases, vaccines that reduce or block infection – and thus transmission – in addition to preventing disease have a greater impact than those that prevent disease alone, due to the indirect protection provided to high-risk groups. We further demonstrate that the health impact of vaccination will depend on the cumulative infection incidence in the population when vaccination begins, the duration of any naturally acquired immunity, the likely trajectory of the epidemic in 2021 and the level of healthcare available to effectively treat those with disease. Within a country, we find that for a limited supply (doses for

Following ini􀀂al declines, in mid 2020, a resurgence in transmission of novel coronavirus disease (COVID-19) has occurred in the United States and parts of Europe. Despite the wide implementa􀀂on of non-pharmaceu􀀂cal inter-ven􀀂ons, it is s􀀂ll not known how they are impacted by changing contact pa􀀁erns, age and other demographics. As COVID-19 disease control becomes more localised, understanding the age demographics driving transmission and how these impact the loosening of interven􀀂ons such as school reopening is crucial. Considering dynamics for the United States, we analyse aggregated, age-specific mobility trends from more than 10 million individuals and link these mechanis􀀂cally to age-specific COVID-19 mortality data. In contrast to previous approaches, we link mobility to mortality via age specific contact pa􀀁erns and use this rich rela􀀂onship to reconstruct accurate trans-mission dynamics. Contrary to anecdotal evidence, we find li􀀁le support for age-shi􀀃s in contact and transmission dynamics over 􀀂me. We es􀀂mate that, un􀀂l August, 63.4% [60.9%-65.5%] of SARS-CoV-2 infec􀀂ons in the United States originated from adults aged 20-49, while 1.2% [0.8%-1.8%] originated from children aged 0-9. In areas with con􀀂nued, community-wide transmission, our transmission model predicts that re-opening kindergartens and el-ementary schools could facilitate spread and lead to considerable excess COVID-19 a􀀁ributable deaths over a 90-day period. These findings indicate that targe􀀂ng interven􀀂ons to adults aged 20-49 are an important con-sidera􀀂on in hal􀀂ng resurgent epidemics, and preven􀀂ng COVID-19-a􀀁ributable deaths when kindergartens and elementary schools reopen.

The COVID-19 pandemic has resulted in substantial mortality worldwide. However, to date, countries in the Middle East and Africa have reported substantially lower mortality rates than in Europe and the Americas. One hypothesis is that these countries have been ‘spared’, but another is that deaths have been under-ascertained (deaths that have been unreported due to any number of reasons, for instance due to limited testing capacity). However, the scale of under-ascertainment is difficult to assess with currently available data. In this analysis, we estimate the potential under-ascertainment of COVID-19 mortality in Damascus, Syria, where all-cause mortality data has been reported between 25th July and 1st August. We fit a mathematical model of COVID-19 transmission to reported COVID-19 deaths in Damascus since the beginning of the pandemic and compare the model-predicted deaths to reported excess deaths. Exploring a range of different assumptions about under-ascertainment, we estimate that only 1.25% of deaths (sensitivity range 1% - 3%) due to COVID-19 are reported in Damascus. Accounting for under-ascertainment also corroborates local reports of exceeded hospital bed capacity. To validate the epidemic dynamics inferred, we leverage community-uploaded obituary certificates as an alternative data source, which confirms extensive mortality under-ascertainment in Damascus between July and August. This level of under-ascertainment suggests that Damascus is at a much later stage in its epidemic than suggested by surveillance reports, which have repo. We estimate that 4,340 (95% CI: 3,250 - 5,540) deaths due to COVID-19 in Damascus may have been missed as of 2nd September 2020. Given that Damascus is likely to have the most robust surveillance in Syria, these findings suggest that other regions of the country could have experienced similar or worse mortality rates due to COVID-19.

Physical review / C 101(6), 064321 (2020). doi:10.1103/PhysRevC.101.064321, Published by APS, Woodbury, NY

Background: COVID-19 has the potential to cause substantial disruptions to health services, including by cases overburdening the health system or response measures limiting usual programmatic activities. We aimed to quantify the extent to which disruptions in services for human immunodeficiency virus (HIV), tuberculosis (TB) and malaria in low- and middle-income countries with high burdens of those disease could lead to additional loss of life. Methods: We constructed plausible scenarios for the disruptions that could be incurred during the COVID-19 pandemic and used established transmission models for each disease to estimate the additional impact on health that could be caused in selected settings. Findings: In high burden settings, HIV-, TB- and malaria-related deaths over five years may increase by up to 10%, 20% and 36%, respectively, compared to if there were no COVID-19 pandemic. We estimate the greatest impact on HIV to be from interruption to antiretroviral therapy, which may occur during a period of high health system demand. For TB, we estimate the greatest impact is from reductions in timely diagnosis and treatment of new cases, which may result from any prolonged period of COVID-19 suppression interventions. We estimate that the greatest impact on malaria burden could come from interruption of planned net campaigns. These disruptions could lead to loss of life-years over five years that is of the same order of magnitude as the direct impact from COVID-19 in places with a high burden of malaria and large HIV/TB epidemics. Interpretation: Maintaining the most critical prevention activities and healthcare services for HIV, TB and malaria could significantly reduce the overall impact of the COVID-19 pandemic. Funding: Bill & Melinda Gates Foundation, The Wellcome Trust, DFID, MRC

Background: Since the start of the COVID-19 epidemic in late 2019, there have been more than 152 affected regions and countries with over 110,000 confirmed cases outside mainland China. Methods: We analysed COVID-19 cases among travellers from mainland China to different regions and countries, comparing the region- and country-specific rates of detected and confirmed cases per flight volume to estimate the relative sensitivity of surveillance in different regions and countries. Results: Although travel restrictions from Wuhan City and other cities across China may have reduced the absolute number of travellers to and from China, we estimated that more than two thirds (70%, 95% CI: 54% - 80%, compared to Singapore; 75%, 95% CI: 66% - 82%, compared to multiple countries) of cases exported from mainland China have remained undetected. Conclusions: These undetected cases potentially resulted in multiple chains of human-to-human transmission outside mainland China.

In response to the COVID-19 pandemic, countries have sought to control transmission of SARS-CoV-2 by restricting population movement through social distancing interventions, reducing the number of contacts. Mobility data represent an important proxy measure of social distancing. Here, we develop a framework to infer the relationship between mobility and the key measure of population-level disease transmission, the reproduction number (R). The framework is applied to 53 countries with sustained SARS-CoV-2 transmission based on two distinct country-specific automated measures of human mobility, Apple and Google mobility data. For both datasets, the relationship between mobility and transmission was consistent within and across countries and explained more than 85% of the variance in the observed variation in transmissibility. We quantified country-specific mobility thresholds defined as the reduction in mobility necessary to expect a decline in new infections (R

Since early March 2020, the COVID-19 epidemic across the United Kingdom has led to a range of social distancing policies, which have resulted in reduced mobility across different regions. Crowd level data on mobile phone usage can be used as a proxy for actual population mobility patterns and provide a way of quantifying the impact of social distancing measures on changes in mobility. Here, we use two mobile phone-based datasets (anonymised and aggregated crowd level data from O2 and from the Facebook app on mobile phones) to assess changes in average mobility, both overall and broken down into high and low population density areas, and changes in the distribution of journey lengths. We show that there was a substantial overall reduction in mobility with the most rapid decline on the 24th March 2020, the day after the Prime Minister’s announcement of an enforced lockdown. The reduction in mobility was highly synchronized across the UK. Although mobility has remained low since 26th March 2020, we detect a gradual increase since that time. We also show that the two different datasets produce similar trends, albeit with some location-specific differences. We see slightly larger reductions in average mobility in high-density areas than in low-density areas, with greater variation in mobility in the high-density areas: some high-density areas eliminated almost all mobility. We are only able to observe populations living in locations where sufficient number of people use Facebook or a device connected to the relevant provider’s network such that no individual is identifiable. These analyses form a baseline with which to monitor changes in behaviour in the UK as social distancing is eased.