bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinematic study of the association Cyg OB3 with Gaia DR2
Authors: Rao Anjali , Gandhi Poshak , Knigge Christian , Paice John A , Leigh Nathan W C , Boubert Douglas
Published: May 2020

We study the stellar kinematic properties and spatial distribution of the association Cyg OB3 using precise astrometric data from Gaia DR2. All known O- and B-type stars in Cyg OB3 region with positions, parallaxes, and proper motions available are included, comprising a total of 41 stars. The majority of stars are found to be concentrated at a heliocentric distance of 2.0 ± 0.3 kpc. The mean peculiar velocity of the sample after removing Galactic rotation and solar motion is ∼22 km s−1, dominated by the velocity component towards the Galactic centre. The relative position and velocity of the black hole X-ray binary Cyg X-1 with respect to the association suggest that Cyg OB3 is most likely its parent association. The peculiar kinematic properties of some of the stars are revealed and are suggestive of past stellar encounters. The sample includes a previously known runaway star HD 227018, and its high peculiar velocity of ∼50 km s−1 is confirmed with Gaia. We estimated the velocities of stars relative to the association and the star HD 225577 exhibits peculiar velocity smaller than its velocity relative to the association. The star has lower value of proper motion than the rest of the sample. The results suggest a slowly expanding nature of the association, which is supported by the small relative speeds (<20 km s−1) with respect to the association for a majority of the sample stars.
SMARCA4deficiency-associated heterochromatin induces intrinsic DNA replication stress and susceptibility to ATR inhibition in lung adenocarcinoma
Authors: Kurashima Kiminori , Kashiwagi Hideto , Shimomura Iwao , Suzuki Ayako , Takeshita Fumitaka , Mazevet Marianne , Harata Masahiko , Yamashita Takayuki , Yamamoto Yusuke , Kohno Takashi , Shiotani Bunsyo
Published: May 2020

The SWI/SNF chromatin remodeling complex regulates transcription through the control of chromatin structure and is increasingly thought to play an important role in human cancer. Lung adenocarcinoma (LADC) patients frequently harbor mutations in SMARCA4, a core component of this multisubunit complex. Most of these mutations are loss-of-function mutations, which disrupt critical functions in the regulation of chromatin architecture and can cause DNA replication stress. This study reports that LADC cells deficient in SMARCA4 showed increased DNA replication stress and greater sensitivity to the ATR inhibitor (ATRi) in vitro and in vivo. Mechanistically, loss of SMARCA4 increased heterochromatin formation, resulting in stalled forks, a typical DNA replication stress. In the absence of SMARCA4, severe ATRi-induced single-stranded DNA, which caused replication catastrophe, was generated on nascent DNA near the reversed forks around heterochromatin in an Mre11-dependent manner. Thus, loss of SMARCA4 confers susceptibility to ATRi, both by increasing heterochromatin-associated replication stress and by allowing Mre11 to destabilize reversed forks. These two mechanisms synergistically increase susceptibility of SMARCA4-deficient LADC cells to ATRi. These results provide a preclinical basis for assessing SMARCA4 defects as a biomarker of ATRi efficacy.
Intrinsic ATR signaling shapes DNA end resection and suppresses toxic DNA-PKcs signaling
Authors: Dibitetto Diego , Sims Jennie R , Ascenção Carolline F R , Feng Kevin , Kim Dongsung , Oberly Susannah , Freire Raimundo , Smolka Marcus B
Published: May 2020

Most cancer cells experience oncogene-induced replication stress and, as a result, exhibit high intrinsic activation of the ATR kinase. Although cancer cells often become more dependent on ATR for survival, the precise mechanism by which ATR signaling ensures cancer cell fitness and viability remains incompletely understood. Here, we find that intrinsic ATR signaling is crucial for the ability of cancer cells to promote DNA end resection, the first step in homology-directed DNA repair. Inhibition of ATR over multiple cell division cycles depletes the pool of pro-resection factors and prevents the engagement of RAD51 as well as RAD52 at nuclear foci, leading to toxic DNA-PKcs signaling and hypersensitivity to PARP inhibitors. The effect is markedly distinct from acute ATR inhibition, which blocks RAD51-mediated repair but not resection and engagement of RAD52. Our findings reveal a key pro-resection function for ATR and define how ATR inhibitors can be used for effective manipulation of DNA end resection capacity and DNA repair outcomes in cancer cells.
Differential role of nicotinamide adenine dinucleotide deficiency in acute and chronic kidney disease
Authors: Faivre Anna , Katsyuba Elena , Verissimo Thomas , Lindenmeyer Maja , Rajaram Renuga Devi , Naesens Maarten , Heckenmeyer Carolyn , Mottis Adrienne , Feraille Eric , Cippà Pietro , Cohen Clemens , Longchamp Alban , Allagnat Florent , Rutkowski Joseph M , Legouis David , Auwerx Johan , de Seigneux Sophie
Published: May 2020

Background

Nicotinamide adenine dinucleotide (NAD+) is a ubiquitous coenzyme involved in electron transport and a co-substrate for sirtuin function. NAD+ deficiency has been demonstrated in the context of acute kidney injury (AKI).

Methods

We studied the expression of key NAD+ biosynthesis enzymes in kidney biopsies from human allograft patients and patients with chronic kidney disease (CKD) at different stages. We used ischaemia–reperfusion injury (IRI) and cisplatin injection to model AKI, urinary tract obstruction [unilateral ureteral obstruction (UUO)] and tubulointerstitial fibrosis induced by proteinuria to investigate CKD in mice. We assessed the effect of nicotinamide riboside (NR) supplementation on AKI and CKD in animal models.

Results

RNA sequencing analysis of human kidney allograft biopsies during the reperfusion phase showed that the NAD+de novo synthesis is impaired in the immediate post-transplantation period, whereas the salvage pathway is stimulated. This decrease in de novo NAD+ synthesis was confirmed in two mouse models of IRI where NR supplementation prevented plasma urea and creatinine elevation and tubular injury. In human biopsies from CKD patients, the NAD+de novo synthesis pathway was impaired according to CKD stage, with better preservation of the salvage pathway. Similar alterations in gene expression were observed in mice with UUO or chronic proteinuric glomerular disease. NR supplementation did not prevent CKD progression, in contrast to its efficacy in AKI.

Conclusion

Impairment of NAD+ synthesis is a hallmark of AKI and CKD. NR supplementation is beneficial in ischaemic AKI but not in CKD models.
Evaluating the Effects of Cerebrospinal Fluid Protein Content on the Performance of Differential Pressure Valves and Antisiphon Devices Using a Novel Benchtop Shunting Model
Authors: Gorelick Noah L , Serra Riccardo , Iyer Rajiv , Um Richard , Grewal Angad , Monroe Audrey , Antoine Hannah , Beharry Kelly , Cecia Arba , Kroll Francesca , Ishida Wataru , Perdomo-Pantoja Alexander , Xu Risheng , Loth Francis , Ye Xiaobu , Suk Ian , Tyler Betty , Bayston Roger , Luciano Mark G
Published: May 2020

BACKGROUND

Hydrocephalus is managed by surgically implanting flow-diversion technologies such as differential pressure valves and antisiphoning devices; however, such hardware is prone to failure. Extensive research has tested them in flow-controlled settings using saline or de-aerated water, yet little has been done to validate their performance in a setting recreating physiologically relevant parameters, including intracranial pressures, cerebrospinal fluid (CSF) protein content, and body position.

OBJECTIVE

To more accurately chart the episodic drainage characteristics of flow-diversion technology. A gravity-driven benchtop model of flow was designed and tested continuously during weeks-long trials.

METHODS

Using a hydrostatic pressure gradient as the sole driving force, interval flow rates of 6 valves were examined in parallel with various fluids. Daily trials in the upright and supine positions were run with fluid output collected from distal catheters placed at alternating heights for extended intervals.

RESULTS

Significant variability in flow rates was observed, both within specific individual valves across different trials and among multiple valves of the same type. These intervalve and intravalve variabilities were greatest during supine trials and with increased protein. None of the valves showed evidence of overt obstruction during 30 d of exposure to CSF containing 5 g/L protein.

CONCLUSION

Day-to-day variability of ball-in-cone differential pressure shunt valves may increase overdrainage risk. Narrow-lumen high-resistance flow control devices as tested here under similar conditions appear to achieve more consistent flow rates, suggesting their use may be advantageous, and did not demonstrate any blockage or trend of decreasing flow over the 3 wk of chronic use.
OsASN1 Overexpression in Rice Increases Grain Protein Content and Yield under Nitrogen-Limiting Conditions
Authors: Lee Sichul , Park Joonheum , Lee Jinwon , Shin Dongjin , Marmagne Anne , Lim Pyung Ok , Masclaux-Daubresse Céline , An Gynheung , Nam Hong Gil
Published: May 2020

Nitrogen (N) is a major limiting factor affecting crop yield in unfertilized soil. Thus, cultivars with a high N use efficiency (NUE) and good grain protein content (GPC) are needed to fulfill the growing food demand and to reduce environmental burden. This is especially true for rice (Oryza sativa L.) that is cultivated with a high input of N fertilizer and is a primary staple food crop for more than half of the global population. Here, we report that rice asparagine synthetase 1 (OsASN1) is required for grain yield and grain protein contents under both N-sufficient (conventional paddy fields) and N-limiting conditions from analyses of knockout mutant plants. In addition, we show that overexpression (OX) of OsASN1 results in better nitrogen uptake and assimilation, and increased tolerance to N limitation at the seedling stage. Under field conditions, the OsASN1 OX rice plants produced grains with increased N and protein contents without yield reduction compared to wild-type (WT) rice. Under N-limited conditions, the OX plants displayed increased grain yield and protein content with enhanced photosynthetic activity compared to WT rice. Thus, OsASN1 can be an effective target gene for the development of rice cultivars with higher grain protein content, NUE, and grain yield under N-limiting conditions.
Efficacy and Safety of Two Fixed-Dose Combinations of Tramadol Hydrochloride and Diclofenac Sodium in Postoperative Dental Pain
Authors: Desjardins Paul , Alvarado Fabian , Gil Martha , González Manuel , Guajardo Rogelio
Published: May 2020

Objective

To evaluate the analgesic efficacy and safety of tramadol hydrochloride/diclofenac sodium fixed-dose combination 25 mg/25 mg (FDC 25/25) and 50 mg/50 mg (FDC 50/50) vs tramadol 50 mg (T50) and diclofenac 50 mg (D50) monotherapies in acute postoperative dental pain.

Setting

Eight sites across Mexico.

Subjects

Adults (N = 829) with moderate to severe pain after third molar extraction.

Design

Prospective, randomized, double-blind, diclofenac- and tramadol-controlled, parallel-group, noninferiority, phase 3 trial.

Methods

Subjects were randomized to receive three doses (one every eight hours) of oral FDC 25/25, FDC 50/50, T50, or D50 over a 24-hour period. Pain intensity and pain relief were evaluated frequently over the 24 hours postdose. Secondary measures included peak pain relief, onset, and duration of effect. The primary objective was to compare the analgesic efficacy and safety of FDC 50/50 or analgesic noninferiority of FDC 25/25 vs D50 or T50. The primary efficacy end point was total pain relief over four hours after dose 1 (TOTPAR4).

Results

TOTPAR4 scores showed that FDC 25/25 was noninferior (P < 0.0001, delta = 1.5) and FDC 50/50 was superior (P < 0.0001) to the individual components. All secondary efficacy measures supported these results. The safety profile of FDC 25/25 and FDC 50/50 was consistent with the known safety profile of D50 and T50 monotherapies, with no unexpected safety findings observed.

Conclusions

Tramadol/diclofenac FDC 25/25 and FDC 50/50 provide superior analgesia for acute pain after third molar extraction than either of the individual components. Minor adverse effects appeared to be related to the higher doses of tramadol.
A novel method for evaluating the dynamic biocompatibility of degradable biomaterials based on real-time cell analysis
Authors: Gai Xiaoxiao , Liu Chenghu , Wang Guowei , Qin Yang , Fan Chunguang , Liu Jia , Shi Yanping
Published: May 2020

Degradable biomaterials have emerged as a promising type of medical materials because of their unique advantages of biocompatibility, biodegradability and biosafety. Owing to their bioabsorbable and biocompatible properties, magnesium-based biomaterials are considered as ideal degradable medical implants. However, the rapid corrosion of magnesium-based materials not only limits their clinical application but also necessitates a more specific biological evaluation system and biosafety standard. In this study, extracts of pure Mg and its calcium alloy were prepared using different media based on ISO 10993:12; the Mg2+ concentration and osmolality of each extract were measured. The biocompatibility was investigated using the MTT assay and xCELLigence real-time cell analysis (RTCA). Cytotoxicity tests were conducted with L929, MG-63 and human umbilical vein endothelial cell lines. The results of the RTCA highly matched with those of the MTT assay and revealed the different dynamic modes of the cytotoxic process, which are related to the differences in the tested cell lines, Mg-based materials and dilution rates of extracts. This study provides an insight on the biocompatibility of biodegradable materials from the perspective of cytotoxic dynamics and suggests the applicability of RTCA for the cytotoxic evaluation of degradable biomaterials.
U.S. Monetary Policy and the Global Financial Cycle
Authors: Miranda-Agrippino Silvia , Rey Hélène
Published: May 2020

U.S. monetary policy shocks induce comovements in the international financial variables that characterize the “Global Financial Cycle.” A single global factor that explains an important share of the variation of risky asset prices around the world decreases significantly after a U.S. monetary tightening. Monetary contractions in the US lead to significant deleveraging of global financial intermediaries, a decline in the provision of domestic credit globally, strong retrenchments of international credit flows, and tightening of foreign financial conditions. Countries with floating exchange rate regimes are subject to similar financial spillovers.
The time course of moral perception: an ERP investigation of the moral pop-out effect
Authors: Gantman Ana , Devraj-Kizuk Sayeed , Mende-Siedlecki Peter , Van Bavel Jay J , Mathewson Kyle E
Published: May 2020

Humans are highly attuned to perceptual cues about their values. A growing body of evidence suggests that people selectively attend to moral stimuli. However, it is unknown whether morality is prioritized early in perception or much later in cognitive processing. We use a combination of behavioral methods and electroencephalography to investigate how early in perception moral words are prioritized relative to non-moral words. The behavioral data replicate previous research indicating that people are more likely to correctly identify moral than non-moral words in a modified lexical decision task. The electroencephalography data reveal that words are distinguished from non-words as early as 200 ms after onset over frontal brain areas and moral words are distinguished from non-moral words 100 ms later over left-posterior cortex. Further analyses reveal that differences in brain activity to moral vs non-moral words cannot be explained by differences in arousal associated with the words. These results suggest that moral content might be prioritized in conscious awareness after an initial perceptual encoding but before subsequent memory processing or action preparation. This work offers a more precise theoretical framework for understanding how morality impacts vision and behavior.
Dorsolateral and dorsomedial prefrontal cortex track distinct properties of dynamic social behavior
Authors: McDonald Kelsey R , Pearson John M , Huettel Scott A
Published: May 2020

Understanding how humans make competitive decisions in complex environments is a key goal of decision neuroscience. Typical experimental paradigms constrain behavioral complexity (e.g. choices in discrete-play games), and thus, the underlying neural mechanisms of dynamic social interactions remain incompletely understood. Here, we collected fMRI data while humans played a competitive real-time video game against both human and computer opponents, and then, we used Bayesian non-parametric methods to link behavior to neural mechanisms. Two key cognitive processes characterized behavior in our task: (i) the coupling of one’s actions to another’s actions (i.e. opponent sensitivity) and (ii) the advantageous timing of a given strategic action. We found that the dorsolateral prefrontal cortex displayed selective activation when the subject’s actions were highly sensitive to the opponent’s actions, whereas activation in the dorsomedial prefrontal cortex increased proportionally to the advantageous timing of actions to defeat one’s opponent. Moreover, the temporoparietal junction tracked both of these behavioral quantities as well as opponent social identity, indicating a more general role in monitoring other social agents. These results suggest that brain regions that are frequently implicated in social cognition and value-based decision-making also contribute to the strategic tracking of the value of social actions in dynamic, multi-agent contexts.
The Social Construction of the Regulatory Burden: Methodological and Substantive Considerations
Authors: Kurtz Marcus , Schrank Andrew
Published: May 2020

What drives the private sector’s attitude toward the public sector? We address the question by regressing survey data on the perceived burden of government regulation on objective data on the nature, cost, and administration of the regulation of entry in different political and economic contexts. The results suggest that businesspeople perceive democratic, regulatory, and left-of-center governments to be inefficient, net of objective conditions, and tax havens to be well-governed despite—or perhaps due to—their lack of transparency. Our findings contribute to both the sociology of knowledge and political sociology by demonstrating that indicators of public sector performance that are derived from surveys of businesspeople and used by donors and investors are not only biased against liberal democracies that try to regulate and/or tax the private sector but—insofar as they influence the flow of public and private resources—a threat to regulation and redistribution in the twenty-first century.
Modeling serological testing to inform relaxation of social distancing for COVID-19 control
Authors: Kraay Alicia N. M. , Nelson Kristin N. , Zhao Conan , Weitz Joshua S. , Lopman Benjamin A.
Published: May 2020

Background

While social distancing efforts have been successful at slowing the spread of SARS-CoV- 2, these measures cannot be sustained indefinitely. In this paper, we examine how serological testing can reduce the risk of relaxing social distancing measures while also providing a way for test-positive individuals to return to more normal levels of activity.

Methods

We use an SEIR-like compartmental model that accounts for serological test status to examine if widespread serological testing can reduce the adverse effects of relaxing social distancing measures, in terms of total deaths and health system burden. In our model, social distancing measures are relaxed to a greater extent for those who test positive compared to those who have not been tested or test negative, allowing a return to work and partial restoration of other social contacts to pre-pandemic levels. All individuals preferentially interact with those who have tested positive, such that seropositive individuals act as immunological ‘shields.’ We consider a range of potential testing capacities and the implications of an imperfect test for this strategy.

Results

Although relaxing social distancing interventions increases total deaths, serologic testing as a part of this strategy can reduce population risk. If social distancing restrictions are relaxed by 50% in tandem with monthly serological testing of the general United States (US) population, 174,000 deaths would be averted and 67% of the US population would be released from social distancing after 1 year, as compared to a scenario without serological testing. Sustaining moderate levels of social distancing can help to flatten the epidemic curve, reducing health system burden below the US critical care capacity.

Implications

Modeling studies suggest that serological testing can be used to relax social distancing measures preferentially for seropositive individuals, insofar as antibodies can be established as a correlate of protection against SARS-CoV-2 infection. Implementing a strategy of serological testing and shielding can reduce population risk while offsetting the severe social and economic costs of a sustained shutdown.
Extensive testing may reduce COVID-19 mortality: a lesson from northern Italy
Authors: Bari Mauro Di , Balzi Daniela , Carreras Giulia , Onder Graziano
Published: May 2020

We examined data on the progression of COVID-19 epidemics in four regions in northern Italy. Lombardy, Emilia-Romagna, and Piedmont had an extremely steeper increase in mortality with increasing number of tests performed than Veneto, which applied a policy of broader swab testing. This suggests that the strategy adopted in Veneto, similar to that in South Korea, is effective in containing COVID-19 epidemics and should be applied in other regions of Italy and countries in Europe.

On February 20, 2020, a first autochthonous case of COVID-19 respiratory disease was observed in Lombardy, Italy (1), soon followed by a second patient in Veneto, which borders Lombardy. Since then, the outbreak has rapidly expanded, mostly in regions in northern Italy (2).

Initially, epidemiological surveillance and strategies for swab testing were under control of regional healthcare authorities. On February 25, the Italian Ministry of Health issued more stringent testing policies for application of swabs to identify COVID-19 cases, prioritizing patients with respiratory symptoms and possible COVID-19 contacts who required hospitalization. Most regions promptly complied with these recommendations, whereas Veneto maintained its policy, implemented after the occurrence of the first cases, of extensive testing and isolation of positive cases (3). Surprisingly, the debate stemming from these different regional policies valued international more than Italian evidences (4). We aimed at assessing, using data from the first month of the Italian experience, how different policies for swab testing may impact on the initial progression of COVID-19 epidemics.

Data were obtained from the reports of the Italian Department of Civil Protection, issued since February 24, which include daily number of swabs performed and deaths from COVID-19 in each region (5). We compared Lombardy, Emilia-Romagna, and Piedmont, three regions in northern Italy that closely followed the recommendations for restrictive COVID-19 testing, and Veneto, which applied a policy of broader testing (3).

Conflict of interest

None declared.

Funding statement

No funding.
Full lockdown policies in Western Europe countries have no evident impacts on the COVID-19 epidemic
Authors: Meunier Thomas
Published: May 2020

This phenomenological study assesses the impacts of full lockdown strategies applied in Italy, France, Spain and United Kingdom, on the slowdown of the 2020 COVID-19 outbreak. Comparing the trajectory of the epidemic before and after the lockdown, we find no evidence of any discontinuity in the growth rate, doubling time, and reproduction number trends. Extrapolating pre-lockdown growth rate trends, we provide estimates of the death toll in the absence of any lockdown policies, and show that these strategies might not have saved any life in western Europe. We also show that neighboring countries applying less restrictive social distancing measures (as opposed to police-enforced home containment) experience a very similar time evolution of the epidemic.
Optimal Pool Size for COVID-19 Group Testing
Authors: Chen Jeffrey Y. , Chen Andrew S. C.
Published: May 2020

This paper presents an analytical formulation for determining optimal pool size in the initial pooling stage and the subsequent retests for COVID-19. A generalized constant compaction approach confirms the efficiency of “halving” targeted population between retest stages. An analytical gain formula is derived to aid future test designs. It is observed that optimal gain relies on the proper choice of the initial pool size. This optimal compaction scheme outperforms the conventional algorithms in most cases and may provide a mathematically-native road map for us to operate beyond the standard super-even-number-based (64, 32, 16, 8…, 1) group testing algorithms.
COVID-19 in healthcare workers in three hospitals in the South of the Netherlands, March 2020
Authors: Sikkema Reina S. , Pas Suzan , Nieuwenhuijse David F. , O’Toole Áine , Verweij Jaco , van der Linden Anne , Chestakova Irina , Schapendonk Claudia , Pronk Mark , Lexmond Pascal , Bestebroer Theo , Overmars Ronald J. , van Nieuwkoop Stefan , van den Bijllaardt Wouter , Bentvelsen Robbert G. , van Rijen Miranda M.L. , Buiting Anton G.M. , van Oudheusden Anne J.G. , Diederen Bram M. , Bergmans Anneke M.C. , van der Eijk Annemiek , Molenkamp Richard , Rambaut Andrew , Timen Aura , Kluytmans Jan A.J.W. , Oude Munnink Bas B. , Kluytmans van den Bergh Marjolein F.Q. , Koopmans Marion P.G.
Published: May 2020

Ten days after the first reported case of SARS-CoV-2 infection in the Netherlands, 3.9% of healthcare workers (HCWs) in nine hospitals located in the South of the Netherlands tested positive for SARS-CoV-2 RNA. The extent of nosocomial transmission that contributed to the HCW infections was unknown.

We combined epidemiological data, collected by means of structured interviews of HCWs, with whole genome sequencing (WGS) of SARS-CoV-2 in clinical samples from HCWs and patients in three of nine hospitals that participated in the HCW screening, to perform an in-depth analysis of sources and modes of transmission of SARS -CoV-2 in HCWs and patients.

A total of 1,796 out of 12,022 HCWs (15%) of the three participating hospitals were screened, based on clinical symptoms, of whom 96 (5%) tested positive for SARS-CoV-2. We obtained complete genome sequences of 50 HCWs and 18 patients. Most sequences grouped in 3 clusters, with 2 clusters displaying local circulation within the region. The observed patterns are most consistent with multiple introductions into the hospitals through community acquired infections, and local amplification in the community.

Although direct transmission in the hospitals cannot be ruled out, the data does not support widespread nosocomial transmission as source of infection in patients or healthcare workers.
Seroprevalence of novel coronavirus disease (COVID-19) in Kobe, Japan
Authors: Doi Asako , Iwata Kentaro , Kuroda Hirokazu , Hasuike Toshikazu , Nasu Seiko , Kanda Aya , Nagao Tomomi , Nishioka Hiroaki , Tomii Keisuke , Morimoto Takeshi , Kihara Yasuki
Published: May 2020

Background

Coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been affecting many people on earth and our society. Japan is known to have relatively less number of infections as well as deaths among developed nations. However, accurate prevalence of COVID-19 in Japan remains unknown. Therefore, we conducted a cross-sectional study to estimate seroprevalence of SARS-CoV-2 infection.

Methods

We conducted a cross-sectional serologic testing for SARS-CoV-2 antibody using 1,000 samples from patients at outpatient settings who visited the clinic from March 31 to April 7, 2020, stratified by the decade of age and sex.

Results

There were 33 positive IgG among 1,000 serum samples (3.3%, 95%CI: 2.3-4.6%). By applying this figure to the census of Kobe City (population: 1,518,870), it is estimated that the number of people with positive IgG be 50,123 (95%CI: 34,934-69,868). Age and sex adjusted prevalence of positivity was calculated 2.7% (95%CI: 1.8-3.9%), and the estimated number of people with positive IgG was 40,999 (95%CI: 27,333-59,221). These numbers were 396 to 858 fold more than confirmed cases with PCR testing in Kobe City.

Conclusions

Our cross-sectional serological study suggests that the number of people with seropositive for SARS-CoV-2 infection in Kobe, Japan is far more than the confirmed cases by PCR testing.
Projection of hospitalization by COVID-19 in Brazil following different social distances policies
Authors: Matheus Henrique , da Silva Ferreira , Pereira Rafael Silva , de Abreu Raquel , Gritz Junqueira , Simões Adolfo , Porto Fabio
Published: May 2020

Following the first infections in the Wuhan City, COVID-19 became a global pandemic as declared by the World Health Organization (WHO). Since it is an airborne disease transmitted between humans, many countries adopted a quarantine on their own population as well as closing borders measures. In Brazil many are discussing the best way to manage the opening of the quarantine under the constraints of hospitals infrastructure. In this work we implement a forecast of the demand for hospital beds for the next 30 days for every state in Brazil for different quarantine flexibilization scenarios and analyse how long it would take for the demand to exceed current available hospital beds.
MODELLING OF COVID-19 OUTBREAK INDICATORS IN CHINA BETWEEN JANUARY AND APRIL
Authors: Çelik Senol , Ankarali Handan , Pasin Ozge
Published: May 2020

Background

The aim of this study is to explain the changes of outbreak indicators for coronavirus in China with nonlinear models and time series analysis. There are lots of methods for modelling. But we want to determine the best mathematical model and the best time series method among other models.

Methods

The data was obtained between January 22 and April 21, 2020 from China records. The number of total cases and the number of total deaths were used for the calculations. For modelling Weibull, Negative Exponential, Von Bertalanffy, Janoscheck, Lundqvist-Korf and Sloboda models were used and AR, MA, ARMA, Holt, Brown and Damped models were used for time series. The determination coefficient (R2), Pseudo R2 and mean square error were used for nonlinear modelling as criteria for determining the model that best describes the number of cases, the number of total deaths and BIC (Bayesian Information Criteria) was used for time series.

Results

According to our results, the Sloboda model among the growth curves and ARIMA (0,2,1) model among the times series models were most suitable models for modelling of the number of total cases. In addition Lundqvist-Korf model among the growth curves and Holt linear trend exponential smoothing model among the times series models were most suitable model for modelling of the number of total deaths. Our time series models forecast that the number of total cases will 83311 on 5 May and the number of total deaths will be 5273.

Conclusions

Because results of the modelling has providing information on measures to be taken and giving prior information for subsequent similar situations, it is of great importance modeling outbreak indicators for each country separately.
Impact of virus testing on COVID-19 case fatality rate: estimate using a fixed-effects model
Authors: Terriau Anthony , Albertini Julien , Poirier Arthur , Le Bastard Quentin
Published: May 2020

Background

In response to the SARS-CoV2 pandemic, governments have adopted a variety of public health measures. There are variations in how much testing has been done across countries. South Korea, Germany, and Iceland take the bet of massive testing of their population. Whereas tests were not performed widely in southern European countries. As the former undergo a lower case-fatality rate due to the COVID-19 than the latter, the impact of the testing strategy must be investigated. In this study, we aimed to evaluate the impact of testing on the case fatality rate.

Methods

We use data on inpatients across French geographic areas and propose a novel methodology that exploits policy discontinuities at region borders to estimate the effect of COVID-19 tests on the case-fatality rate. In France, testing policies are determined locally. We compare all contiguous department pairs located on the opposite sides of a region border. The heterogeneity in testing rate between department pairs together with the similarities in other dimensions allow us to mimic the existence of treatment and control groups and to identify the impact of testing on mortality.

Results

The increase of one percentage point in the test rate is associated with a decrease of 0.001 percentage point in the death rate. In other words, for each additional 1000 tests, one person would have remained alive.

Conclusion

Massive population testing could have a significant effect on mortality in different ways. Mass testing may help decision-makers to implement healthcare measures to limit the spread of the disease.
Prediction of Extubation Readiness Using Transthoracic Ultrasound in Preterm Infants
Authors: Soliman Reem M. , Elsayed Yasser , Said Reem N. , Abdulbaqi Abdulaziz M. , Hashem Rania H. , Aly Hany
Published: May 2020

Objective

To test the hypothesis that a lung ultrasound severity score (LUSsc) and assessment of left ventricular eccentricity index of the interventricular septum (LVEI) by focused heart ultrasound can predict extubation success in mechanically ventilated preterm infants with respiratory distress syndrome (RDS).

Design

Prospective observational study of premature infants <34 weeks’ of gestation age supported with mechanical ventilation due to RDS. LUSsc and LVEI were performed on postnatal days 3 and 7 by an investigator who was masked to infants’ ventilator parameters and clinical conditions. RDS was classified based on LUSsc into mild (score 0–9) and moderate-severe (score 10–18). A receiver operator curve was constructed to assess the ability to predict extubation success. Pearson’s correlation was performed between LVEI and pulmonary artery pressure (PAP).

Setting

Level III neonatal intensive care unit, Cairo, Egypt.

Results

A total of 104 studies were performed to 66 infants; of them 39 had mild RDS (LUSsc 0–9) and 65 had moderate-severe RDS (score ≥10). LUSsc predicted extubation success with a sensitivity and a specificity of 91% and 69%; the positive and negative predictive values were 61% and 94%, respectively. Area under the curve (AUC) was 0.83 (CI: 0.75-0.91). LVEI did not differ between infants that succeeded and failed extubation. However, it correlated with pulmonary artery pressure during both systole (r=0.62) and diastole (r=0.53) and with hemodynamically significant patent ductus arteriosus (r=0.27 and r=0.46, respectively).

Conclusion

LUSsc predicts extubation success in preterm infants with RDS whereas LVEI correlates with high PAP.
Modeling and Short-Term Forecasts of Indicators for COVID-19 Outbreak in 25 Countries at the end of March
Authors: Ankaralı Handan , Erarslan Nadire , Pasin Özge
Published: May 2020

Background

The coronavirus, which originated in Wuhan, causing the disease called COVID-19, spread more than 200 countries and continents end of the March. There is a lot of data since the virus started. However, these data will be explanatory when accurate analyzes are made and will allow future predictions to be made. In this study, it was aimed to model the outbreak with different time series models and also predict the indicators.

Methods

The data was collected from 25 countries which have different process at least 20 days. ARIMA(p,d,q), Simple Exponential Smoothing, Holt’s Two Parameter, Brown’s Double Exponential Smoothing Models were used. The prediction and forecasting values were obtained for the countries. Trends and seasonal effects were also evaluated.

Results

China has almost under control according to forecasting. The cumulative death prevalence in Italy and Spain will be the highest, followed by the Netherlands, France, England, China, Denmark, Belgium, Brazil and Sweden respectively as of the first week of April. The highest daily case prevalence was observed in Belgium, America, Canada, Poland, Ireland, Netherlands, France and Israel between 10% and 12%.The lowest rate was observed in China and South Korea. Turkey was one of the leading countries in terms of ranking these criteria. The prevalence of the new case and the recovered were higher in Spain than Italy.

Conclusions

More accurate predictions for the future can be obtained using time series models with a wide range of data from different countries by modelling real time and retrospective data.
Mathematical Modeling of Listeriosis Incorporating Effects of Awareness Programs
Authors: Chukwu C. W. , Nyabadza F.
Published: May 2020

Awareness programs by the media play a pivotal role in the control of infectious diseases. In this paper, we formulate and analyse a mathematical model for listeriosis incorporating aware individuals. Mathematical analyses of the model are done and equilibrium points determined. The model has three equilibria; namely; the disease-free, the bacteria-free, and the endemic equilibria. Local asymptotic stability of the equilibria is established based on the food contamination number ℛf. Numerical simulations are carried out and the effects of various parameters on the model state variables investigated. The results from numerical simulations reveal that an increase in the efficacy of awareness programs, the rate of implementation of awareness programs, and the rate at which unaware susceptible become aware result in the reduction of listeriosis in the human population. The results have important implications in the control and management of listeriosis.
Defining Facets of Social Distancing during the COVID-19 Pandemic: Twitter Analysis
Authors: Kwon Jiye , Grady Connor , Feliciano Josemari T. , Fodeh Samah J.
Published: May 2020

Social distancing has been one of the primary mitigation strategies in the United States to control the spread of novel coronavirus disease (COVID-19) and can be viewed as a multi-faceted public health measure. Using Twitter data, we aim to (1) define and quantify the prevalence and evolution of facets of social distancing during the COVID-19 pandemic in the US in a spatiotemporal context and (2) examine the most amplified tweets among social distancing facets. We analyzed a total of 259,529 unique tweets containing “coronavirus” from 115,485 unique users between January 23, 2020 and March 24, 2020 that were identified by the Twitter API as English and U.S.-based. Tweets containing specified keywords (determined a priori) were grouped into six social distancing facets: implementation, purpose, social disruption, adaptation, positive emotions, and negative emotions. Tweets about social disruptiveness were most retweeted, and implementation tweets were most favorited. Social distancing tweets became overall more prevalent in the U.S. from late January to March but were not geographically uniform. In January and February, facets of social distancing appeared in Los Angeles, San Francisco, and Seattle, which were among the first cities impacted by the COVID-19 outbreak. Tweets related to the “implementation” and “negative emotions” facets of social distancing largely dominated in combination with topics of “social disruption” and “adaptation”, albeit to a lesser degree. Social distancing can be defined in terms of facets that respond and represent certain moments and events in a pandemic, including travel restrictions and rising COVID-19 case counts. For example, in February, Miami, FL had a low volume of social distancing tweets but grew in March which corresponded with the rise of COVID-19 cases in the city. This suggests that overall volume of social distancing tweets can reflect the relative case count in respective locations.
Estimates of the ongoing need for social distancing and control measures post-“lockdown” from trajectories of COVID-19 cases and mortality
Authors: Lonergan Mike , Chalmers James
Published: May 2020

By 29th April 2020, COVID-19 had caused more than 3 million cases across more than 200 countries. And most countries with significant outbreaks had introduced social distancing or “lockdown” measures to reduce viral transmission. So the key question now is when, how, and to what extent, these measures can be lifted.

By fitting regression models to publically available data on daily numbers of newly-confirmed cases and mortality, trajectories, doubling times and reproduction number (R0) were estimated both before and under the control measures. These data ran up to 29th April 2020, and covered 73 countries that had provided sufficient data for modelling.

The estimates of R0, before lockdown, based on these data were broadly consistent with those previously published at between 2.0 and 3.7 in the countries with the largest number of cases available for analysis (USA, Italy, Spain, France and UK). There was little evidence to suggest that the restrictions had reduced R far below 1 in many places, with France having the most rapid reductions – R0 0.77 (95%CI 0.68-0.87), based on cases and 0.78 (95%CI 0.68-0.88) based on mortality.

Intermittent lockdown has been proposed as a means of controlling the outbreak while allowing periods of increase freedom and economic activity. These data suggest that few countries could have even one week per month unrestricted without seeing resurgence of the epidemic. Similarly, restoring 20% of the activity that has been prevented by the lockdowns looks difficult to reconcile with preventing the resurgence of the disease in most countries.
Modeling Return of the Epidemic: Impact of Population Structure, Asymptomatic Infection, Case Importation and Personal Contacts
Authors: Yu Xinhua
Published: May 2020

Background

Proactive interventions have halted the pandemic of coronavirus infected disease in some regions. However, without reaching herd immunity, the return of epidemic is possible. We investigate the impact of population structure, case importation, asymptomatic cases, and the number of contacts on a possible second wave of epidemic through mathematical modelling.

Methods

we built a modified Susceptible-exposed-Infectious-Removed (SEIR) model with parameters mirroring those of the COVID-19 pandemic and reported simulated characteristics of epidemics for incidence, hospitalizations and deaths under different scenarios.

Results

A larger percent of elderly people leads to higher number of hospitalizations, while a large percent of prior infection will effectively curb the epidemic. The number of imported cases and the speed of importation have small impact on the epidemic progression. However, a higher percent of asymptomatic cases slows the epidemic down and reduces the number of hospitalizations and deaths at the epidemic peak. Finally, reducing the number of contacts among young people alone has moderate effects on themselves, but little effects on the elderly population. However, reducing the number of contacts among elderly people alone can mitigate the epidemic significantly in both age groups, even though young people remain active within themselves.

Conclusion

Reducing the number of contacts among high risk populations alone can mitigate the burden of epidemic in the whole society. Interventions targeting high risk groups may be more effective in containing or mitigating the epidemic.
Compositional Cyber-Physical Epidemiology of COVID-19
Authors: Ro Jin Woo , Allen Nathan , Ai Weiwei , Prasad Debi , Roop Partha S.
Published: May 2020

COVID-19 pandemic has posed significant challenges globally. Countries have adopted different strategies with varying degrees of success. Epidemiologists are studying the impact of government actions using scenario analysis. However, the interactions between the government policy and the disease dynamics are not formally captured.

We, for the first time, formally study the interaction between the disease dynamics, which is modelled as a physical process, and the government policy, which is modelled as the adjoining controller. Our approach enables compositionality, where either the plant or the controller could be replaced by an alternative model. Our work is inspired by the engineering approach for the design of Cyber-Physical Systems (CPSs). Consequently, we term the new framework Compositional Cyber-Physical Epidemiology (CCPE). We created different classes of controllers and applied these to control the disease in New Zealand and Italy. Our controllers closely follow government decisions based on their published data. We not only reproduce the pandemic progression faithfully in New Zealand and Italy but also show the tradeoffs produced by differing control actions.
Mobility data can explain the entire COVID-19 outbreak course in Japan
Authors: Kurita Junko , Sugawara Tamie , Ohkusa Yasushi
Published: May 2020

Background

In Japan, as a countermeasure against the COVID-19 outbreak, voluntary restrictions against going out (VRG) have been applied.

Object

We examined mobility information provided by Apple Inc. to a susceptible–infected–recovery model.

Method

When applying a polynomial function to daily Apple data with the SIR model, we presumed the function up to a cubic term as in our earlier study.

Results

Estimation results demonstrated R0as 1.507 and its 95% confidence interval was [1.502, 1.509].. The estimated coefficients of Apple data was 1.748 and its 95% confidence interval was [1.731, 1.788].

Discussion and Conclusion

Results show that mobility data from Apple Inc. can explain the entire course of the outbreak in COVID-19 in Japan. Therefore, monitoring Apple data might be sufficient to adjust control measures to maintain an effective reproduction number of less than one.
Determining the source of transmission of SARS-CoV-2 infection in a healthcare worker
Authors: Safdar Nasia , Moreno Gage K. , Braun Katarina M. , Friedrich Thomas C. , O’Connor David H.
Published: May 2020

Background

Healthcare workers (HCWs) are at the frontlines of the COVID-19 pandemic and are at risk of exposure to SARS-CoV-2 infection from their interactions with patients and in the community (1, 2). Limited availability of recommended personal protective equipment (PPE), in particular N95 respirators, has fueled concerns about whether HCWs are adequately protected from exposure while caring for patients. Understanding the source of SARS-CoV-2 infection in a HCW – the community or the healthcare system – is critical for understanding the effectiveness of hospital infection control and PPE practices. In Dane County, Wisconsin, community prevalence of SARS-CoV-2 is relatively low (cumulative prevalence of ~0.06% – positive cases / total population in Dane county as of April 17). Although SARS-CoV-2 infections in HCWs are often presumed to be acquired during the course of patient care, there are few reports unambiguously identifying the source of acquisition.

Objective

To determine the source of transmission of SARS-CoV-2 in a healthcare worker.