Phase sensitivity determines the lowest optical path length (OPL) value that can be detected from the noise floor in a quantitative phase microscopy (QPM) system. The temporal phase sensitivity is known to be limited by both photon shot-noise and a variety of noise sources from electronic devices and environment. To beat temporal phase sensitivity limit, we explore different ways to reduce different noise factors in off-axis interferometry-based QPM using laser-illumination. Using a high electron-well-capacity camera, we measured the temporal phase sensitivity values using non-common-path and common-path interferometry based QPM systems under different environmental conditions. A frame summing method and a spatiotemporal filtering method are further used to reduce the noise contributions, thus enabling us to push the overall temporal phase sensitivity to less than 2 picometers.
{"title":"Beating temporal phase sensitivity limit in off-axis interferometry based quantitative phase microscopy","authors":"Yujie Nie, R. Zhou","doi":"10.1063/5.0034515","DOIUrl":"https://doi.org/10.1063/5.0034515","url":null,"abstract":"Phase sensitivity determines the lowest optical path length (OPL) value that can be detected from the noise floor in a quantitative phase microscopy (QPM) system. The temporal phase sensitivity is known to be limited by both photon shot-noise and a variety of noise sources from electronic devices and environment. To beat temporal phase sensitivity limit, we explore different ways to reduce different noise factors in off-axis interferometry-based QPM using laser-illumination. Using a high electron-well-capacity camera, we measured the temporal phase sensitivity values using non-common-path and common-path interferometry based QPM systems under different environmental conditions. A frame summing method and a spatiotemporal filtering method are further used to reduce the noise contributions, thus enabling us to push the overall temporal phase sensitivity to less than 2 picometers.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125865428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mass concentrations of birds, or lack of such, is a phenomenon of great ecological and domestic significance. Apart from being and indicator for e.g. food availability, ecological change and population size, it is also a source of conflict between humans and birds. Moreover, massive gatherings or colonies of birds also get the attention of the public -- either as a spectacular phenomenon or as an unwelcome pest -- thereby forming the public perception of birds and their abundance. In the context of the mass concentration of bramblings (Fringilla montifringilla) in Sweden the winter 2019-2020, this work reviews the literature on this striking phenomenon. Winter roosts are found to amount to on the order of one million birds per hectare of roost area, but the spread between reports is significant. Support for roosts of up to around 15 million birds was found, but much larger numbers are frequently recited in the literature. It is argued that these larger numbers are the result of overestimation or, in some cases, even completely unfounded (potentially typos). While the difficulties related to the count of large numbers of birds can explain this state, it is unfortunate that "high numbers" sometimes displace proper numbers. Since incorrect data, and its persistence, may result in that incorrect conclusions are drawn from new observations, this matter deserves attention. As the Brambling is a well-studied species, the matter also raises concerns regarding numbers for mass concentrations of other species. It is recommended that very large numbers of birds should be recited and used with care: underlying data and methods of the original sources should be scrutinized. Analogously, reporters of large numbers of birds are advised to describe and document counting methods. In particular, number estimates based on flock volume and bird density should be avoided.
{"title":"A review of mass concentrations of Bramblings Fringilla montifringilla: implications for assessment of large numbers of birds","authors":"T. Svensson","doi":"10.34080/OS.V31.22031","DOIUrl":"https://doi.org/10.34080/OS.V31.22031","url":null,"abstract":"Mass concentrations of birds, or lack of such, is a phenomenon of great ecological and domestic significance. Apart from being and indicator for e.g. food availability, ecological change and population size, it is also a source of conflict between humans and birds. Moreover, massive gatherings or colonies of birds also get the attention of the public -- either as a spectacular phenomenon or as an unwelcome pest -- thereby forming the public perception of birds and their abundance. In the context of the mass concentration of bramblings (Fringilla montifringilla) in Sweden the winter 2019-2020, this work reviews the literature on this striking phenomenon. Winter roosts are found to amount to on the order of one million birds per hectare of roost area, but the spread between reports is significant. Support for roosts of up to around 15 million birds was found, but much larger numbers are frequently recited in the literature. It is argued that these larger numbers are the result of overestimation or, in some cases, even completely unfounded (potentially typos). While the difficulties related to the count of large numbers of birds can explain this state, it is unfortunate that \"high numbers\" sometimes displace proper numbers. Since incorrect data, and its persistence, may result in that incorrect conclusions are drawn from new observations, this matter deserves attention. As the Brambling is a well-studied species, the matter also raises concerns regarding numbers for mass concentrations of other species. It is recommended that very large numbers of birds should be recited and used with care: underlying data and methods of the original sources should be scrutinized. Analogously, reporters of large numbers of birds are advised to describe and document counting methods. In particular, number estimates based on flock volume and bird density should be avoided.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125936778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
James Zou, Aubrey Johnson, Jeanelle France, S. Bharadwaj, Zeljko Tomljanovic, Y. Stern, A. Brickman, D. Devanand, J. Luchsinger, W. Kreisl, F. Provenzano
Image registration is an important preprocessing step in neuroimaging which allows for the matching of anatomical and functional information between modalities and subjects. This can be challenging if there are gross differences in image geometry or in signal intensity, such as in the case of some molecular PET radioligands, where control subjects display relative lack of signal relative to noise within intracranial regions, and may have off target binding that may be confused as other regions, and may vary depending on subject. The use of intermediary images or volumes have been shown to aide registration in such cases. To account for this phenomena within our own longitudinal aging cohort, we generated a population specific MRI and PET template from a broad distribution of 30 amyloid negative subjects. We then registered the PET image of each of these subjects, as well as a holdout set of thirty 'template-naive' subjects to their corresponding MRI images using the template image as an intermediate using three different sets of registration parameters and procedures. To evaluate the performance of both conventional registration and our method, we compared these to the registration of the attenuation CT (acquired at time of PET acquisition) to MRI as the reference. We then used our template to directly derive SUVR values without the use of MRI. We found that conventional registration was comparable to an existing CT based standard, and there was no significant difference in errors collectively amongst all methods tested. In addition, there were no significant differences between existing and MR-less tau PET quantification methods. We conclude that a template-based method is a feasible alternative to, or salvage for, direct registration and MR-less quantification; and, may be preferred in cases where there is doubt about the similarity between two image modalities.
{"title":"Spatial Registration Evaluation of [18F]-MK6240 PET","authors":"James Zou, Aubrey Johnson, Jeanelle France, S. Bharadwaj, Zeljko Tomljanovic, Y. Stern, A. Brickman, D. Devanand, J. Luchsinger, W. Kreisl, F. Provenzano","doi":"10.7916/D8-BF13-CY63","DOIUrl":"https://doi.org/10.7916/D8-BF13-CY63","url":null,"abstract":"Image registration is an important preprocessing step in neuroimaging which allows for the matching of anatomical and functional information between modalities and subjects. This can be challenging if there are gross differences in image geometry or in signal intensity, such as in the case of some molecular PET radioligands, where control subjects display relative lack of signal relative to noise within intracranial regions, and may have off target binding that may be confused as other regions, and may vary depending on subject. The use of intermediary images or volumes have been shown to aide registration in such cases. \u0000To account for this phenomena within our own longitudinal aging cohort, we generated a population specific MRI and PET template from a broad distribution of 30 amyloid negative subjects. We then registered the PET image of each of these subjects, as well as a holdout set of thirty 'template-naive' subjects to their corresponding MRI images using the template image as an intermediate using three different sets of registration parameters and procedures. To evaluate the performance of both conventional registration and our method, we compared these to the registration of the attenuation CT (acquired at time of PET acquisition) to MRI as the reference. We then used our template to directly derive SUVR values without the use of MRI. \u0000We found that conventional registration was comparable to an existing CT based standard, and there was no significant difference in errors collectively amongst all methods tested. In addition, there were no significant differences between existing and MR-less tau PET quantification methods. We conclude that a template-based method is a feasible alternative to, or salvage for, direct registration and MR-less quantification; and, may be preferred in cases where there is doubt about the similarity between two image modalities.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115115731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Domino, M. Romaszewski, Tomasz Jasi'nski, Malgorzata Ma'sko
Infrared thermography (IRT) is a valuable diagnostic tool in equine veterinary medicine however, little is known about its application in donkeys. The aim was to find patterns in thermal images of donkeys and horses, and determine if these patterns share similarities. The study was carried out on 18 donkeys and 16 horses. All equids underwent thermal imaging with an infrared camera and measuring the skin thickness and hair coat length. On the class maps of each thermal image, 15 regions of interest (ROIs) were annotated and then combined into 10 groups of ROIs (GORs). The existence of statistically significant differences between surface temperatures in GORs was tested both `globally' for all animals of a given species and `locally' for each animal. Two special cases of animals that differ from the rest were also discussed. Our results indicated that the majority of thermal patterns are similar for both species however, average surface temperatures in horses are higher than in donkeys. It may be related to differences in the skin and hair coat. We concluded, the patterns of both species are associated with GORs, rather than an individual ROI, with higher uniformity of donkeys patterns.
{"title":"Comparison of surface thermal patterns of horses and donkeys in IRT images","authors":"M. Domino, M. Romaszewski, Tomasz Jasi'nski, Malgorzata Ma'sko","doi":"10.5281/ZENODO.4085075","DOIUrl":"https://doi.org/10.5281/ZENODO.4085075","url":null,"abstract":"Infrared thermography (IRT) is a valuable diagnostic tool in equine veterinary medicine however, little is known about its application in donkeys. The aim was to find patterns in thermal images of donkeys and horses, and determine if these patterns share similarities. The study was carried out on 18 donkeys and 16 horses. All equids underwent thermal imaging with an infrared camera and measuring the skin thickness and hair coat length. On the class maps of each thermal image, 15 regions of interest (ROIs) were annotated and then combined into 10 groups of ROIs (GORs). The existence of statistically significant differences between surface temperatures in GORs was tested both `globally' for all animals of a given species and `locally' for each animal. Two special cases of animals that differ from the rest were also discussed. Our results indicated that the majority of thermal patterns are similar for both species however, average surface temperatures in horses are higher than in donkeys. It may be related to differences in the skin and hair coat. We concluded, the patterns of both species are associated with GORs, rather than an individual ROI, with higher uniformity of donkeys patterns.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"369 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115473500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-30DOI: 10.26226/morressier.5e5e709500701ceba4a2695c
Marina Kazarian, Sandra A. Fadel, A. Mahajan, M. Aboian
Volumetric measurements are known to provide more information when it comes to segmenting tumors, in comparison to one- and two-dimensional measurements, and thus can lead to better informed therapy. In this work, we review the free and easily accessible computer platforms available for conducting these 3D measurements, such as Horos and 3D Slicer and compare the segmentations to commercial Visage software. We compare the time for 3D segmentation of tumors and demonstrate how to use a novel plugin that we developed in 3D slicer for the efficient and accurate segmentation of the cystic component of a tumor.
{"title":"Utilization of 3D segmentation for measurement of pediatric brain tumor outcomes after treatment: review of available tools, step-by-step instructions, and applications to clinical practice","authors":"Marina Kazarian, Sandra A. Fadel, A. Mahajan, M. Aboian","doi":"10.26226/morressier.5e5e709500701ceba4a2695c","DOIUrl":"https://doi.org/10.26226/morressier.5e5e709500701ceba4a2695c","url":null,"abstract":"Volumetric measurements are known to provide more information when it comes to segmenting tumors, in comparison to one- and two-dimensional measurements, and thus can lead to better informed therapy. In this work, we review the free and easily accessible computer platforms available for conducting these 3D measurements, such as Horos and 3D Slicer and compare the segmentations to commercial Visage software. We compare the time for 3D segmentation of tumors and demonstrate how to use a novel plugin that we developed in 3D slicer for the efficient and accurate segmentation of the cystic component of a tumor.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117013564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Morozov, R. Reshetnikov, Victor A. Gombolevskiy, N. Ledikhova, I. Blokhin, V. Kljashtorny, O. Mokienko, A. Vladzymyrskyy
The controversy of computed tomography (CT) use in COVID-19 screening is associated with ambiguous characteristics of chest CT as a diagnostic test. The reported values of CT sensitivity and specificity calculated using RT-PCR as a reference standard vary widely. The objective of this study was to reevaluate the diagnostic and prognostic value of CT using an alternative approach. This study included 973 symptomatic COVID-19 patients aged 42 $pm$ 17 years, 56% females. We reviewed the disease dynamics between the initial and follow-up CT studies using a "CT0-4" grading system. Sensitivity and specificity were calculated as conditional probabilities that a patient's condition would improve or deteriorate relative to the initial CT study results. For the calculation of negative (NPV) and positive (PPV) predictive values, we estimated the COVID-19 prevalence in Moscow. We used several ARIMA and EST models with different parameters to fit the data on total cases of COVID-19 from March 6, 2020, to July 20, 2020, and forecast the incidence. The "CT0-4" grading scale demonstrated low sensitivity (28%) but high specificity (95%). The best statistical model for describing the pandemic in Moscow was ETS with multiplicative trend, error, and season type. According to our calculations, with the predicted prevalence of 2.1%, the values of NPV and PPV would be 98% and 10%, correspondingly. We associate the low sensitivity and PPV values with the small sample size of the patients with severe symptoms and non-optimal methodological setup for measuring these specific characteristics. The "CT0-4" grading scale was highly specific and predictive for identifying admissions to hospitals of COVID-19 patients. Despite the ambiguous accuracy, chest CT proved to be an effective practical tool for patient management during the pandemic, provided that the necessary infrastructure and human resources are available.
{"title":"Diagnostic accuracy of computed tomography for identifying hospitalizations for patients with COVID-19","authors":"S. Morozov, R. Reshetnikov, Victor A. Gombolevskiy, N. Ledikhova, I. Blokhin, V. Kljashtorny, O. Mokienko, A. Vladzymyrskyy","doi":"10.17816/DD46818","DOIUrl":"https://doi.org/10.17816/DD46818","url":null,"abstract":"The controversy of computed tomography (CT) use in COVID-19 screening is associated with ambiguous characteristics of chest CT as a diagnostic test. The reported values of CT sensitivity and specificity calculated using RT-PCR as a reference standard vary widely. The objective of this study was to reevaluate the diagnostic and prognostic value of CT using an alternative approach. This study included 973 symptomatic COVID-19 patients aged 42 $pm$ 17 years, 56% females. We reviewed the disease dynamics between the initial and follow-up CT studies using a \"CT0-4\" grading system. Sensitivity and specificity were calculated as conditional probabilities that a patient's condition would improve or deteriorate relative to the initial CT study results. For the calculation of negative (NPV) and positive (PPV) predictive values, we estimated the COVID-19 prevalence in Moscow. We used several ARIMA and EST models with different parameters to fit the data on total cases of COVID-19 from March 6, 2020, to July 20, 2020, and forecast the incidence. The \"CT0-4\" grading scale demonstrated low sensitivity (28%) but high specificity (95%). The best statistical model for describing the pandemic in Moscow was ETS with multiplicative trend, error, and season type. According to our calculations, with the predicted prevalence of 2.1%, the values of NPV and PPV would be 98% and 10%, correspondingly. We associate the low sensitivity and PPV values with the small sample size of the patients with severe symptoms and non-optimal methodological setup for measuring these specific characteristics. The \"CT0-4\" grading scale was highly specific and predictive for identifying admissions to hospitals of COVID-19 patients. Despite the ambiguous accuracy, chest CT proved to be an effective practical tool for patient management during the pandemic, provided that the necessary infrastructure and human resources are available.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132863968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-29DOI: 10.1061/(ASCE)GT.1943-5606.0002509
Yuze Wang, K. Soga, J. DeJong, A. Kabla
Microbial-Induced Carbonate Precipitation (MICP) has been explored for more than a decade as a promising soil improvement technique. However, it is still challenging to predict and control the growth rate and characteristics of CaCO3 precipitates, which directly affect the engineering performance of MICP-treated soils. In this study, we employ a microfluidics-based pore scale model to observe the effect of bacterial density on the growth rate and characteristics of CaCO3 precipitates during MICP processes occurring at the sand particle scale. Results show that the precipitation rate of CaCO3 increases with bacterial density in the range between 0.6e8 and 5.2e8 cells/ml. Bacterial density also affects both the size and number of CaCO3 crystals. A low bacterial density of 0.6e8 cells/ml produced 1.1e6 crystals/ml with an average crystal volume of 8,000 um3, whereas a high bacterial density of 5.2e8 cells/ml resulted in more crystals (2.0e7 crystals/ml) but with a smaller average crystal volume of 450 um3. The produced CaCO3 crystals were stable when the bacterial density was 0.6e8 cells/ml. When the bacterial density was 4-10 times higher, the crystals were first unstable and then transformed into more stable CaCO3 crystals. This suggests that bacterial density should be an important consideration in the design of MICP protocols.
{"title":"Effects of Bacterial Density on Growth Rate and Characteristics of Microbial-Induced CaCO3 Precipitates: Particle-Scale Experimental Study","authors":"Yuze Wang, K. Soga, J. DeJong, A. Kabla","doi":"10.1061/(ASCE)GT.1943-5606.0002509","DOIUrl":"https://doi.org/10.1061/(ASCE)GT.1943-5606.0002509","url":null,"abstract":"Microbial-Induced Carbonate Precipitation (MICP) has been explored for more than a decade as a promising soil improvement technique. However, it is still challenging to predict and control the growth rate and characteristics of CaCO3 precipitates, which directly affect the engineering performance of MICP-treated soils. In this study, we employ a microfluidics-based pore scale model to observe the effect of bacterial density on the growth rate and characteristics of CaCO3 precipitates during MICP processes occurring at the sand particle scale. Results show that the precipitation rate of CaCO3 increases with bacterial density in the range between 0.6e8 and 5.2e8 cells/ml. Bacterial density also affects both the size and number of CaCO3 crystals. A low bacterial density of 0.6e8 cells/ml produced 1.1e6 crystals/ml with an average crystal volume of 8,000 um3, whereas a high bacterial density of 5.2e8 cells/ml resulted in more crystals (2.0e7 crystals/ml) but with a smaller average crystal volume of 450 um3. The produced CaCO3 crystals were stable when the bacterial density was 0.6e8 cells/ml. When the bacterial density was 4-10 times higher, the crystals were first unstable and then transformed into more stable CaCO3 crystals. This suggests that bacterial density should be an important consideration in the design of MICP protocols.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122536866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-19DOI: 10.1101/2020.04.19.20071860
J. Mora, Sandra P'erez, I. Rodr'iguez, A. N'unez, A. Dvorzhak
A semiempirical model, based in the logistic map, has been succesfully applied to forecast important quantities along the several phases of the outbreak of the covid-19 for different countries. This paper shows how the model was calibrated and applied to perform predictions of people needing to be hospitalized, needs of ventilators, or the number of deaths which would be produced. It is shown specifically the results obtained in the case of Spain, showing a prediction of diagnosed infected and deaths which will be observed after the ease of the total lockdown produced the 13th of March. Is also shown how this model can provide an insight of what the level of infection in the different regions of Spain is forecasted. The model predicts for Spain for the end of May more than 400,000 diagnosed infected cases, number which will be probably higher due to the change in the possibilities of performing massive number of tests to the general population. The number of forecasted deaths for that date is 46,000 +/- 15,000. The model also predicts the level of infection at the different Spanish regions, providing a counterintuitive result in the cases of Madrid and Catalonia as the result shows a higher the level of infection at Catalonia than the level at Madrid, according with this model. All of these results can be used to guide policy makers in order to optimize resources and to avoid future outbreaks of the covid-19.
{"title":"A Semiempirical Dynamical Model to Forecast the Propagation of Epidemics: The Case of the Sars-Cov-2 in Spain","authors":"J. Mora, Sandra P'erez, I. Rodr'iguez, A. N'unez, A. Dvorzhak","doi":"10.1101/2020.04.19.20071860","DOIUrl":"https://doi.org/10.1101/2020.04.19.20071860","url":null,"abstract":"A semiempirical model, based in the logistic map, has been succesfully applied to forecast important quantities along the several phases of the outbreak of the covid-19 for different countries. This paper shows how the model was calibrated and applied to perform predictions of people needing to be hospitalized, needs of ventilators, or the number of deaths which would be produced. It is shown specifically the results obtained in the case of Spain, showing a prediction of diagnosed infected and deaths which will be observed after the ease of the total lockdown produced the 13th of March. Is also shown how this model can provide an insight of what the level of infection in the different regions of Spain is forecasted. The model predicts for Spain for the end of May more than 400,000 diagnosed infected cases, number which will be probably higher due to the change in the possibilities of performing massive number of tests to the general population. The number of forecasted deaths for that date is 46,000 +/- 15,000. The model also predicts the level of infection at the different Spanish regions, providing a counterintuitive result in the cases of Madrid and Catalonia as the result shows a higher the level of infection at Catalonia than the level at Madrid, according with this model. All of these results can be used to guide policy makers in order to optimize resources and to avoid future outbreaks of the covid-19.","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123000151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-15DOI: 10.1007/978-3-642-32882-4_3
H. Banks, A. Cintrón-Arias, A. Cintrón-Arias, F. Kappel, F. Kappel
{"title":"Parameter selection methods in inverse problem formulation","authors":"H. Banks, A. Cintrón-Arias, A. Cintrón-Arias, F. Kappel, F. Kappel","doi":"10.1007/978-3-642-32882-4_3","DOIUrl":"https://doi.org/10.1007/978-3-642-32882-4_3","url":null,"abstract":"","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116110989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-02DOI: 10.1007/978-3-030-46306-9_14
N. Georgiou, I. Kiss, P. Simon
{"title":"Theoretical and Numerical Considerations of the Assumptions Behind Triple Closures in Epidemic Models on Networks","authors":"N. Georgiou, I. Kiss, P. Simon","doi":"10.1007/978-3-030-46306-9_14","DOIUrl":"https://doi.org/10.1007/978-3-030-46306-9_14","url":null,"abstract":"","PeriodicalId":119149,"journal":{"name":"arXiv: Quantitative Methods","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121553819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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