scholarly journals Improved screening of COVID-19 cases through a Bayesian network symptoms model and psychophysical olfactory test

Author(s):  
Susana Eyheramendy ◽  
Pedro A. Saa ◽  
Eduardo A. Undurraga ◽  
Carlos Valencia ◽  
Carolina López ◽  
...  

AbstractThe infectiousness and presymptomatic transmission of COVID-19 hinder pandemic control efforts worldwide. Therefore, the frequency of testing, accessibility, and immediate results are critical for reopening societies until an effective vaccine becomes available for a substantial proportion of the population. The loss of sense of smell is among the earliest, most discriminant, and prevalent symptoms of COVID-19, with 75-98% prevalence when clinical olfactory tests are used. Frequent screening for olfactory dysfunction could substantially reduce viral spread. However, olfactory dysfunction is generally self-reported and not measured, which is specially problematic as partial olfactory impairment is broadly unrecognized. To address this limitation, we developed a rapid psychophysical olfactory test (KOR) deployed on a web platform for automated reporting and traceability based on a low-cost, six-odor olfactory identification kit. Based on test results, we defined an anosmia score –a classifier for olfactory impairment–, and a Bayesian Network (BN) model that incorporates other symptoms for detecting COVID-19 cases. We trained and validated the BN model on two samples: suspected COVID-19 cases in five healthcare centers (n = 926; 32% COVID-19 prevalence) and healthy (asymptomatic) mining workers (n = 1, 365; 1.1% COVID-19 prevalence). All participants had COVID-19 assessment by RT-PCR assay. Using the BN model, we predicted COVID-19 status with 76% accuracy (AUC=0.79 [0.75 − 0.82]) in the healthcare sample and 84% accuracy (AUC=0.71 [0.63 − 0.79]) among miners. The KOR test and BN model enabled the detection of COVID-19 cases that otherwise appeared asymptomatic. Our results confirmed that olfactory dysfunction is the most discriminant symptom to predict COVID-19 status when based on olfactory function measurements. Overall, this work highlights the potential for low-cost, frequent, accessible, routine testing for COVID-19 surveillance to aid society’s reopening.

2009 ◽  
Vol 111 (5) ◽  
pp. 958-962 ◽  
Author(s):  
Gemma Escartin Martin ◽  
Carme Junqué ◽  
Montserrat Juncadella ◽  
Andreu Gabarrós ◽  
Maria Angels de Miquel ◽  
...  

Object Olfactory dysfunction has an important impact on quality of life. In patients with subarachnoid hemorrhage (SAH), anosmia has mainly been reported after surgery for aneurysms of the anterior communicating artery (ACoA). The authors studied whether and how frequently patients with ACoA aneurysms present with smell identification deficits in 2 treatment groups (endovascular and surgical treatment). Methods A prospective study was conducted of patients with SAH caused by ruptured ACoAs and who had a Glasgow Outcome Scale score of 1 or 2, in comparison with a control group matched by age and sex. Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT). Results A total of 39 patients were enrolled. A marked olfactory impairment was observed in patients with ruptured ACoAs compared with the control group (p < 0.001). Seventeen patients with ruptured ACoAs (44%) compared with 1 patient in the control group (3%) showed a smell identification deficit according to performance on the UPSIT (p < 0.001). Both groups that underwent treatment presented with olfactory impairment. Ten (59%) of 17 patients who underwent aneurysmal clip placement versus 6 (28.5%) of 21 patients who underwent coil embolization scored below the 25th percentile on the UPSIT, and surgical patients also performed worse than endovascular patients (p = 0.048). The authors observed a worse performance on the olfactory test in patients subjected to endovascular coil embolization when cerebral vasospasm (p = 0.037) or frontal cerebral lesions (p = 0.009) were present. This difference was not observed in patients who underwent surgery. Conclusions Olfactory disorders after SAH caused by rupture of the ACoA are very frequent and were present in both treatment groups. Cerebral vasospasm and frontal lobe lesions are related to worse performance on an olfactory test in patients undergoing endovascular coil embolization.


Author(s):  
Tianpei Tang ◽  
Senlai Zhu ◽  
Yuntao Guo ◽  
Xizhao Zhou ◽  
Yang Cao

Evaluating the safety risk of rural roadsides is critical for achieving reasonable allocation of a limited budget and avoiding excessive installation of safety facilities. To assess the safety risk of rural roadsides when the crash data are unavailable or missing, this study proposed a Bayesian Network (BN) method that uses the experts’ judgments on the conditional probability of different safety risk factors to evaluate the safety risk of rural roadsides. Eight factors were considered, including seven factors identified in the literature and a new factor named access point density. To validate the effectiveness of the proposed method, a case study was conducted using 19.42 km long road networks in the rural area of Nantong, China. By comparing the results of the proposed method and run-off-road (ROR) crash data from 2015–2016 in the study area, the road segments with higher safety risk levels identified by the proposed method were found to be statistically significantly correlated with higher crash severity based on the crash data. In addition, by comparing the respective results evaluated by eight factors and seven factors (a new factor removed), we also found that access point density significantly contributed to the safety risk of rural roadsides. These results show that the proposed method can be considered as a low-cost solution to evaluating the safety risk of rural roadsides with relatively high accuracy, especially for areas with large rural road networks and incomplete ROR crash data due to budget limitation, human errors, negligence, or inconsistent crash recordings.


Author(s):  
Jacopo Pasquini ◽  
Carlo Maremmani ◽  
Stefano Salvadori ◽  
Vincenzo Silani ◽  
Nicola Ticozzi

Abstract Background Olfactory dysfunction in coronavirus disease 2019 (COVID-19) is common during acute illness and appears to last longer than other symptoms. The aim of this study was to objectively investigate olfactory dysfunction in two cohorts of patients at two different stages: during acute illness and after a median recovery of 4 months. Methods Twenty-five acutely ill patients and 26 recovered subjects were investigated. Acute patients had a molecular diagnosis of COVID-19; recovered subjects had a positive antibody assay and a negative molecular test. A 33-item psychophysical olfactory identification test tailored for the Italian population was performed. Results Median time from symptoms onset to olfactory test was 33 days in acute patients and 122 days in recovered subjects. The former scored a significantly higher number of errors at psychophysical testing (median [IQR]: 8 [13] vs 3 [2], p < 0.001) and were more frequently hyposmic (64% vs 19%, p = 0.002). Recovered subjects reported a variable time to subjective olfactory recovery, from days up to 4 months. Participants included in the study reported no significant nasal symptoms at olfactory testing. Among recovered subject who reported olfactory loss during acute COVID-19, four (27%) were still hyposmic. Demographic and clinical characteristics did not show significant associations with olfactory dysfunction. Conclusion Moderate-to-severe hospitalized patients showed a high level and frequency of olfactory dysfunction compared to recovered subjects. In the latter group, subjects who reported persisting olfactory dysfunction showed abnormal scores on psychophysical testing, indicating that, at least in some subjects, persistent hyposmia may represent a long-term sequela of COVID-19.


Author(s):  
G A Parker ◽  
Y B Sun

The work presented in this paper deals mainly with a mechatronic approach to compact disc valve design and concentrates on improvements to the disc valve electromagnetic characteristics, the diaphragm design and the dynamic performance. A novel diaphragm-disc force motor has been successfully developed incorporating a pair of permanent ring magnets. It has the advantages of low electric power consumption at the null position, dual-lane electrical structure for fail-safe operation, high control accuracy and should be competitive with existing torque motors due to its low cost and simple construction. The research involved designing and testing a prototype disc pilot valve with a dual-lane operating mode. The test results showed that the valve has satisfactory static and dynamic characteristics for industrial applications.


2021 ◽  
Author(s):  
Hsiu An Lee ◽  
Hsin-Hua Kung ◽  
Wei-Chen Wu ◽  
Jai Ganesh Udayasankaran ◽  
Yu-Chih Wei ◽  
...  

BACKGROUND The coronavirus disease 2019 (COVID-19) is an ongoing global pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). The prevention and treatment methods for COVID-19 are not yet clear. At present, there are at least 287 preventive vaccines against COVID-19 in the world, of which 5 vaccines are available for emergency use as of June 2021, but none has completed clinical trial. Nevertheless, with the development of vaccines, disease conditions in various countries are gradually controlled. OBJECTIVE The vaccination rate has increased in time, and activities in various countries have gradually recovered. Therefore, the focus of the next stage is confirming and proving that everyone is vaccinated to ensure that those without vaccines will not become a breach in the next wave of diseases. The vaccination or RT-PCR test results are all certified and verified by paper documents issued by hospitals or testing institutions. Meanwhile, falsified documents are a major risk factor in confirming the vaccination status and laboratory test results. Although the Vaccine Passport (VP) may become an important key to future global activities based on the current strategy, the problems of document verification and data use among countries have not yet been resolved. METHODS The blockchain architecture proposed in this research can be applied together by public and private entities and be rapidly expanded. Furthermore, the open ledger of blockchain achieves transparency and data accuracy. On the other hand, smart contracts (SCs) achieve authorization and authentication, while the encryption and decryption mechanisms achieve data protection. In order to make it globally available, the international data standard “Fast Healthcare Interoperability Resource (FHIR)” is adopted into this research. In general, this blockchain architecture can achieve global vaccine passport verification accurately and at a low cost. RESULTS The open nature of the blockchain contributes to establishing transparency and data accuracy. Total three entities are included in this blockchain architecture. All of the authorization are public in the open ledger. The smart certificate enables authorization and authentication, while the encryption and decryption mechanism ensure data protection. This proof of concept demonstrates the design of blockchain architecture which, when adopted, can achieve global vaccine passport verification accurately and at a cost country can afford. An actual vaccine passport case was established and demonstrated in this study. Open blockchain, individually authorized authentication mechanisms, and international standard vaccine passports were adopted. CONCLUSIONS Blockchain architecture is used to build the authentication process of an executable international vaccine passport, with advantages of low cost, high interoperability, effectiveness, security and verifiability.


2002 ◽  
Vol 124 (3) ◽  
pp. 205-211 ◽  
Author(s):  
John H. Lau ◽  
S. W. Ricky Lee ◽  
Stephen H. Pan ◽  
Chris Chang

An elasto-plastic-creep analysis of a low-cost micro via-in-pad (VIP) substrate for supporting a solder bumped flip chip in a chip scale package (CSP) format which is soldered onto a printed circuit board (PCB) is presented in this study. Emphasis is placed on the design, materials, and reliability of the micro VIP substrate and of the micro VIP CSP solder joints on PCB. The solder is assumed to obey Norton’s creep law. Cross-sections of samples are examined for a better understanding of the solder bump, CSP substrate redistribution, micro VIP, and solder joint. Also, the thermal cycling test results of the micro VIP CSP PCB assembly is presented.


2014 ◽  
Vol 12 ◽  
pp. 61-66 ◽  
Author(s):  
Pavol Kajánek

Inertial navigation system (INS) is a self-contained navigation technique. Its main purpose is to determinate the position and the trajectory of the object´s movement in space. This technique is well represented not only as a supplementary method (GPS/INS integrated system) but as an autonomous system for navigation of vehicles and pedestrians, also. The aim of this paper is to design a test for low-cost inertial measurement units. The test results give us information about accuracy, which determine the possible use in indoor navigation or other applications. There are described some methods for processing the data obtained by inertial measurement units, which remove noise and improve accuracy of position and orientation.


Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1590
Author(s):  
Chiara Terrosi ◽  
Gabriele Anichini ◽  
Jean Denis Docquier ◽  
Gianni Gori Savellini ◽  
Claudia Gandolfo ◽  
...  

Blue LED light has proven to have a powerful bacteria-killing ability; however, little is known about its mechanism of virucidal activity. Therefore, we analyzed the effect of blue light on different respiratory viruses, such as adenovirus, respiratory syncytial virus and SARS-CoV-2. The exposure of samples to a blue LED light with a wavelength of 420 nm (i.e., in the visible range) at 20 mW/cm2 of irradiance for 15 min appeared optimal and resulted in the complete inactivation of the viral load. These results were similar for all the three viruses, demonstrating that both enveloped and naked viruses could be efficiently inactivated with blue LED light, regardless of the presence of envelope and of the viral genome nature (DNA or RNA). Moreover, we provided some explanations to the mechanisms by which the blue LED light could exert its antiviral activity. The development of such safe and low-cost light-based devices appears to be of fundamental utility for limiting viral spread and for sanitizing small environments, objects and surfaces, especially in the pandemic era.


Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 355
Author(s):  
Qudeer Hussain ◽  
Anat Ruangrassamee ◽  
Somnuk Tangtermsirikul ◽  
Panuwat Joyklad ◽  
Anil C. Wijeyewickrema

This research investigates the behavior of square concrete columns externally wrapped by low-cost and easily available fiber rope reinforced polymer (FRRP) composites. This study mainly aims to explore the axial stress-strain relationships of FRRP-confined square columns. Another objective is to assess suitable predictive models for the ultimate strength and strain of FRRP-confined square columns. A total of 60 square concrete columns were cast, strengthened, and tested under compression. The parameters were the corner radii of square columns (0, 13, and 26 mm) and different materials of FRRP composites (polyester, hemp, and cotton FRRP composites). The strength and deformability of FRRP-confined specimens were observed to be higher than the unconfined specimens. It was observed that strength gains of FRRP-confined concrete columns and corner radii were directly proportional. The accuracy of ultimate strength and strain models developed for synthetic FRRP-confined square columns was assessed using the test results of this study, showing the need for the development of improved predictive models for FRRP-confined square columns. Newly developed unified models were found to be accurate in predicting the ultimate strength and strain of FRRP-confined columns.


2007 ◽  
Vol 8 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Melanie Drummond ◽  
Jacinta Douglas ◽  
John Olver

AbstractMost people only recognise the value of olfactory function after it is lost. In the context of traumatic brain injury with its far-reaching physical, cognitive, behavioural and emotional sequelae, posttraumatic olfactory dysfunction is an additional consequence that many survivors have to face as they adjust to a changed life situation. The aim of this article is to provide an update on posttraumatic anosmia for clinicians working in the area of brain injury rehabilitation. Brief reviews of incidence studies and causal mechanisms of olfactory impairment after brain injury are provided. Consequences of anosmia in the domains of safety, eating, personal hygiene, leisure, work and relationships with associated adaptive strategies are described.


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