30 research outputs found
Stochastic models and methods for the assessment of earthquake risk in insurance
The problem of earthquake risk assessment and management in insurance is a
challenging one at the interface of geophysics, engineering seismology, stochastics,
insurance mathematics and economics. In this work, I propose stochastic
models and methods for the assessment of earthquake risk from an insurer's
point of view, where the aim is not to address problems in the financial mathematics
and economics of risk selection, pricing, portfolio management, and
risk transfer strategies such as reinsurance and securitisation, but to enable the
latter through the characterisation of the foundation of any risk management
consideration in insurance: the distribution of losses over a period of time for a
portfolio of risks.
Insurance losses are assumed to be generated by a loss process that is in turn
governed by an earthquake process, a point process marked with the earthquake's
hypocentre and magnitude, and a conditional loss distribution for an insurance
portfolio, governing the loss size given the hypocentre and magnitude of the
earthquake, and the physical characteristics of the portfolio as described in the
individual policy records.
From the modeling perspective, I examine the (non-trivial) minutiae around
the infrastructure underpinning the loss process. A novel model of the earthquake
process, a Poisson marked point process with spatial gamma intensity
measure on the hypocentral space, and extensions of the Poisson and stress
release models through the inclusion of hypocentral location in the mark, are
proposed. I discuss the general architectural considerations for constructing the
conditional loss distribution, and propose a new model as an alternative to the
traditional ground motion attenuation and seismic vulnerability approach in
engineering risk assessment. On the actuarial mathematics front, given a fully
specified loss process, I address the problem of constructing simulation based
and, where possible, analytical approximations to the distribution of portfolio
losses over a period of time.
I illustrate the applicability of the stochastic models and methods proposed
in this work through the analysis of a residential homeowners property catastrophe
portfolio exposed to earthquake risk in California. I construct approximations
to the distribution of portfolio losses over a period of time under each
of the three models of the earthquake process that I propose, and discuss their
relative merits
Scouting polyphony in late ancient Christianity : an overview of different conceptualisations of otherness based on the juxtaposition of institutional and non-institutional voices
The purpose of this thesis is to problematize the complexity and the variety of voices that dialogued by the end of the third century a.D. in Rome in order to contribute to shape the phenomenon we have come to know as Christianity. The research question is:as opposed to using just a source associated with the Church, what additional perspectives are provided by the juxtaposition of more voices in order to conceptualise alterity within Christianity in this foundational moment? In order to answer it, I use three sources (Eusebius’ Historia Ecclesiastica, Lactantius’ De Mortibus Persecutorum and the Memoria Apostolorum graffiti in Via Appia, Rome), which provide a variety of voices associated with a range social actors. The objective is to give a broader account of Christian alterity in late antiquity by means of applying a dialogic approach. Originally proposed by Mikhail Bakhtin, this hermeneutic paradigm seeks to juxtapose the voices of all the social actors implied in order to show the conflict between. Given that it would not be possible to juxtapose all the possible sources, I base my analysis in a historical framework grounded on secondary literature that also acts as a metadiscursive context to interpret the sources.
I make use of mixed methods based on content analysis, using MaxQDA to code segments in all three sources and then analyse their frequencies in order to delineate which variables are more relevant to analyse. I thereafter present comments; first analysing only Eusebius’ text, then analysing all three together and showing the conflict between them. Finally, I contrast both conceptualisations. My main conclusion is that an open ended account of history represents alterity in a more complex way that allows researchers to make folk discourses visible, as was the case for these three sources, despite having the risk of being more chaotic
Efficacy Studies of a Trivalent Vaccine Containing PCV-2a, PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Days of Age and 3 Weeks Later against Porcine Circovirus 2 (PCV-2) Infection
Four studies under preclinical and clinical conditions were performed to evaluate the efficacy of a new trivalent vaccine against Porcine circovirus 2 (PCV-2) infection. The product contained
inactivated PCV-1/PCV-2a (cPCV-2a) and PCV-1/PCV-2b (cPCV-2b) chimeras, plus M. hyopneumoniae
inactivated cell-free antigens, which was administered to piglets in a two-dose regime at 3 days
of age and 3 weeks later. The overall results of preclinical and clinical studies show a significant
reduction in PCV-2 viraemia and faecal excretion, and lower histopathological lymphoid lesions and
PCV-2 immunohistochemistry scores in vaccinated pigs when compared to non-vaccinated ones.
Furthermore, in field trial A, a statistically significant reduction in the incidence of PCV-2-subclinical
infection, an increase in body weight from 16 weeks of age to slaughterhouse and an average daily
weight gain over the whole period (from 3 days of age to slaughterhouse) was detected in the vaccinated group when compared to the non-vaccinated one. Circulation of PCV-2a in field trial A, and
PCV-2b plus PCV-2d in field trial B was confirmed by virus sequencing. In conclusion, a double
immunization with a cPCV-2a/cPCV-2b/M. hyopneumoniae vaccine was efficacious against PCV-2
infection by reducing the number of histopathological lymphoid lesions and PCV-2 detection in
tissues, serum, and faeces, as well as reducing losses in productive parameters.info:eu-repo/semantics/publishedVersio
Efficacy Studies of a Trivalent Vaccine Containing PCV-2a, PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Days of Age and 3 Weeks Later against Porcine Circovirus 2 (PCV-2) Infection
Four studies under preclinical and clinical conditions were performed to evaluate the efficacy of a new trivalent vaccine against Porcine circovirus 2 (PCV-2) infection. The product contained inactivated PCV-1/PCV-2a (cPCV-2a) and PCV-1/PCV-2b (cPCV-2b) chimeras, plus M. hyopneumoniae inactivated cell-free antigens, which was administered to piglets in a two-dose regime at 3 days of age and 3 weeks later. The overall results of preclinical and clinical studies show a significant reduction in PCV-2 viraemia and faecal excretion, and lower histopathological lymphoid lesions and PCV-2 immunohistochemistry scores in vaccinated pigs when compared to non-vaccinated ones. Furthermore, in field trial A, a statistically significant reduction in the incidence of PCV-2-subclinical infection, an increase in body weight from 16 weeks of age to slaughterhouse and an average daily weight gain over the whole period (from 3 days of age to slaughterhouse) was detected in the vaccinated group when compared to the non-vaccinated one. Circulation of PCV-2a in field trial A, and PCV-2b plus PCV-2d in field trial B was confirmed by virus sequencing. In conclusion, a double immunization with a cPCV-2a/cPCV-2b/ M. hyopneumoniae vaccine was efficacious against PCV-2 infection by reducing the number of histopathological lymphoid lesions and PCV-2 detection in tissues, serum, and faeces, as well as reducing losses in productive parameters
Efficacy Studies against PCV-2 of a New Trivalent Vaccine including PCV-2a and PCV-2b Genotypes and Mycoplasma hyopneumoniae When Administered at 3 Weeks of Age
This study aimed to evaluate the efficacy of a new trivalent vaccine containing inactivated
Porcine Circovirus 1-2a and 1-2b chimeras and a Mycoplasma hyopneumoniae bacterin administered to
pigs around 3 weeks of age. This trivalent vaccine has already been proved as efficacious in a splitdose regimen but has not been tested in a single-dose scenario. For this purpose, a total of four studies
including two pre-clinical and two clinical studies were performed. Globally, a significant reduction
in PCV-2 viraemia and faecal excretion was detected in vaccinated pigs compared to non-vaccinated
animals, as well as lower histopathological lymphoid lesion plus PCV-2 immunohistochemistry
scorings, and incidence of PCV-2-subclinical infection. Moreover, in field trial B, a significant increase
in body weight and in average daily weight gain were detected in vaccinated animals compared to
the non-vaccinated ones. Circulation of PCV-2b in field trial A and PCV-2a plus PCV-2d in field trial B
was confirmed by virus sequencing. Hence, the efficacy of this new trivalent vaccine against a natural
PCV-2a, PCV-2b or PCV-2d challenge was demonstrated in terms of reduction of histopathological
lymphoid lesions and PCV-2 detection in tissues, serum and faeces, as well as improvement of
production parameters.info:eu-repo/semantics/publishedVersio
Analysis of protein-coding genetic variation in 60,706 humans
Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. We describe the aggregation and analysis of high-quality exome (protein-coding region) sequence data for 60,706 individuals of diverse ethnicities generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of truncating variants with 72% having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human “knockout” variants in protein-coding genes
Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry
Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality
The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients
Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation
4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica
Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil.
El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país.
La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica.
Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas
Anales del III Congreso Internacional de Vivienda y Ciudad "Debate en torno a la nueva agenda urbana"
Acta de congresoEl III Congreso Internacional de Vivienda y Ciudad “Debates en torno a la NUEVa Agenda Urbana”, ha sido una apuesta de alto compromiso por acercar los debates centrales y urgentes que tensionan el pleno ejercicio del derecho a la ciudad. Para ello las instituciones organizadoras (INVIHAB –Instituto de Investigación de Vivienda y Hábitat y MGyDH-Maestría en Gestión y Desarrollo Habitacional-1), hemos convidado un espacio que se concretó con potencia en un debate transdisciplinario. Convocó a intelectuales de prestigio internacional, investigadores, académicos y gestores estatales, y en una metodología de innovación articuló las voces académicas con las de las organizaciones sociales y/o barriales en el Foro de las Organizaciones Sociales que tuvo su espacio propio para dar voz a quienes están trabajando en los desafíos para garantizar los derechos a la vivienda y los bienes urbanos en nuestras ciudades del Siglo XXI