Three Studies on Cybersecurity Disclosure and Assurance

This dissertation comprises three experimental studies that explore how management\u27s financial disclosure behavior and security strategies influence the costs associated with cybersecurity breaches. The first study examines the cost of litigation in connection with cybersecurity incidents. The purpose of this study is to determine how the characteristics and content of cybersecurity incidents\u27 disclosure affects jurors\u27 liability assessments. Specifically, this study explores how jurors react to management timeliness in disclosing the incident and the plausibility of the explanations provided to justify the disclosure strategy. The second and third studies explore the value relevance of cybersecurity risk management (CRM) assurance. In particular, the second study examines whether engagement in voluntary assurance over CRM before the occurrence of an incident affects investors\u27 reactions after the incident, and whether these reactions differ based on whether assurance is expected or not expected based on industry norms. The third study scrutinizes how perceptions of disclosure timeliness affect investor decisions and explores the use of CRM assurance as a potential tool to mitigate the deleterious effects of delayed disclosures of cybersecurity incidents. Overall, the results reported in this dissertation suggest that timely disclosure of a cybersecurity breach reduces liability, improves management credibility assessments, and results in higher valuation judgments. Moreover, the findings reveal that CRM assurance further leads to enhanced management credibility assessments and valuation judgments and that the impact of CRM assurance is particularly beneficial when not necessarily expected for the industry. In combination, these three studies address calls for research exploring the costs of cybersecurity and inform regulators currently engaged in developing both cybersecurity disclosure requirements and voluntary assurance services designed to address stakeholders\u27 information needs regarding companies\u27 cybersecurity activities. These studies also add to the literature and theory documenting the link between disclosure timeliness and litigation risk, and the value of voluntary assurance services

Pulsed light inactivation of mushroom polyphenol oxidase: a fluorometric and spectrophotometric study

Polyphenol oxidase (PPO) is one of the most important food enzymes, it is responsible for the browning of many foods. Pulsed light (PL) is a non-thermal method of food preservation that is able to inactivate PPO. The aim of this work was to gain insight into the mechanism of PPO inactivation by PL. To this, the kinetics of PPO inactivation by PL was measured, together with associated changes in tryptophan fluorescence, KI fluorescence quenching and turbidity; and results were analysed by parameter A and phase diagram methods. Enzyme inactivation followed the Weibull model. Tryptophan fluorescence decreased during PL treatment, as well as the parameter A, while Stern-Volmer constants increased and turbidity was constant. The phase diagram showed only two populated states. There was a high correlation between the loss of activity and parameter A. Results indicate that under the experimental conditions, the inactivation of PPO by PL is an all-or-none process where the enzyme progressively unfolds with no evidence of aggregation.Fundación Universitaria San Antonio de CartagenaCiencias de la Alimentació

Canitas Turísticas

En Colombia cada día se hace más necesaria la creación de empresa como aporte al crecimiento de la economía del país. Se debe motivar a la población Colombia a procurar un estado de salud y bienestar para los adultos mayores a través de la iniciativa de desarrollar una agencia de viajes que incluya asistencia médica, aprovechando el crecimiento sostenido de esta población en los últimos años. El presente estudio aporta evidencias que avalan la importancia de fomentar iniciativas de recreación y turismo para los Adultos Mayores y así promover la integración social y mejorar la calidad de vida de éstos.In Colombia every day becomes more necessary to create company as a contribution to the growth of the economy. It should encourage Colombia to pursue population health status and welfare for the elderly through the initiative of developing a travel agency that includes medical care, taking advantage of the sustained growth of this population in recent years. This study provides evidence supporting the importance of promoting recreation and tourism initiatives for Aging and thus promote social inclusion and improve the quality of life for them.Especialista en Gestión Human

Physiology and Pathology of Autoimmune Diseases: Role of CD4+ T cells in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by synovial inflammation leading to bone erosion and to systemic manifestations in patients with long RA duration. Although the aetiology is unknown, several observations make currently clear that CD4 T cells play a key role in the pathogenesis: (1) RA associates with certain polymorphisms of HLA class II molecules, and (2) the repertoire and aging of CD4 T cells as well as the intracellular signalling mediating CD4 T cell activation are altered in RA patients. We describe herein the alterations found in CD4 T cells and the role of these cells in the development and progression of RA

HOST INSTAR PREFERENCE OF MIRAX INSULARIS (MUESEBECK) (HYMENOPTERA: BRACONIDAE), A KOINOBIONT PARASITOID OF LEUCOPTERA COFFEELLA GUERIN-MÉNÉVILLE (LEPIDOPTERA: LYONETIIDAE)

HOST INSTAR PREFERENCE OF MIRAX INSULARIS (MUESEBECK) (HYMENOPTERA: BRACONIDAE), A KOINOBIONT PARASITOID OF LEUCOPTERA COFFEELLA GUERIN-MÉNÉVILLE (LEPIDOPTERA: LYONETIIDAE

Un estudio sobre la desarticulación entre la semejanza y la trigonometría en el bachillerato

Se reporta parte de una investigación que trata sobre el estudio local de la proporcionalidad geométrica y su articulación con el resto de los temas –particularmente la trigonometría– que conforman el curso de Matemáticas III del plan de estudios de escuelas preparatorias incorporadas a la Universidad de Sonora. En este extracto, se proponen algunos constructos de la Teoría Antropológica de lo Didáctico (TAD) que fundamentaron el estudio, y que en este documento tienen el propósito de darle sentido a la presentación del Marco Epistemológico de Referencia, el cual fue pieza clave en el estudio mencionado, tanto para determinar el nivel de articulación existente, como para contar con una base para proponer acciones específicas acordes a la articulación propuesta, de tal modo que mediante ellas fuera factible una construcción funcional de los conocimientos geométricos

Blockade of the Interaction of Calcineurin with FOXO in Astrocytes Protects Against Amyloid-βInduced Neuronal Death

Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer’s disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD associated pathological inflammation, suggesting a potential new druggable target for this devastating disease. We have now developed decoy molecules to interfere with calcineurin/FOXO3 interactions, and tested them in astrocytes and neuronal co-cultures exposed to amyloid-β (Aβ) toxicity. We observed that interference of calcineurin/FOXO3 interactions exerts a protective action against A-induced neuronal death and favors the production of a set of growth factors that we hypothesize form part of a cytoprotective pathway to resolve inflammation. Furthermore, interference of the A-induced interaction of calcineurin with FOXO3 by decoy compounds significantly decreased amyloid-β protein precursor (AβPP) synthesis, reduced the AβPP amyloidogenic pathway, resulting in lower Alevels, and blocked the expression of pro-inflammatory cytokines TNFα and IL-6 in astrocytes. Collectively, these data indicate that interrupting pro-inflammatory calcineurin/FOXO3 interactions in astrocytes triggered by Aβ accumulation in brain may constitute an effective new therapeutic approach in AD. Future studies with intranasal delivery, or brain barrier permeable decoy compounds, are warranted

The impact of baryons on dark matter haloes

We analyse the dark matter (DM) distribution in a approx 10^12 M_sun halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. Although the DM profiles get more concentrated as baryons are collected at the centre of the haloes compared to a pure dynamical run, the total baryonic mass alone is not enough to fully predict the reaction of the DM profile. We also note that baryons affect the DM distribution even outside the central regions. Those systems where the transformation of gas into stars is regulated by Supernova (SN) feedback, so that significant disc structures are able to form, are found to have more concentrated dark matter profiles than a galaxy which has efficiently transformed most of its baryons into stars at early times. The accretion of satellites is found to be associated with an expansion of the dark matter profiles, triggered by angular momentum transfer from the incoming satellites. As the impact of SN feedback increases, the satellites get less massive and are even strongly disrupted before getting close to the main structure causing less angular momentum transfer. Our findings suggest that the response of the DM halo is driven by the history of assembly of baryons into a galaxy along their merger tree.Comment: 5 pages, 5 figures, accepted for publication in MNRA

The ciliary machinery is repurposed for T cell immune synapse trafficking of LCK

Upon engagement of the T cell receptor with an antigen-presenting cell, LCK initiates TCR signaling by phosphorylating its activation motifs. However, the mechanism of LCK activation specifically at the immune synapse is a major question. We show that phosphorylation of the LCK activating Y394, despite modestly increasing its catalytic rate, dramatically focuses LCK localization to the immune synapse. We describe a trafficking mechanism whereby UNC119A extracts membrane-bound LCK by sequestering the hydrophobic myristoyl group, followed by release at the target membrane under the control of the ciliary ARL3/ARL13B. The UNC119A N terminus acts as a “regulatory arm” by binding the LCK kinase domain, an interaction inhibited by LCK Y394 phosphorylation, thus together with the ARL3/ARL13B machinery ensuring immune synapse focusing of active LCK. We propose that the ciliary machinery has been repurposed by T cells to generate and maintain polarized segregation of signals such as activated LCK at the immune synapse

Teoría de “los móviles y las finalidades” línea jurisprudencial

La teoría de los móviles y las finalidades propone una manera dinámica de observar abordar la procedencia de las acciones de nulidad y de nulidad y restablecimiento del derecho; teniendo en cuenta el contenido de los actos acusados, los efectos de su declaratoria de nulidad y la relación del accionante con los efectos del acto administrativo. Esta teoría, es producto de una construcción jurisprudencial, y busca realizar un control efectivo sobre la legalidad de las decisiones de la administración y evitar el desconocimiento de los derechos subjetivos por parte de la administración pública. Así mismo, para la protección de los derechos sustanciales de los asociados y defensa de la legalidad