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Facing the quantum attack threat, a quantum-resistant version of the SSH Transport Layer protocol has been proposed and been standardized by an IETF working group. This standardization process has been motivated by the fact that if practical quantum computers become available, classical key exchange algorithms used today will no longer be safe because their security can be efficiently broken by Shor’s algorithm running on a quantum computer. In this paper, we construct a symbolic model of the proposed protocol, specify it in the specification language CafeOBJ, and conduct a formal analysis of the claimed security properties with the employment of a formal method tool called Invariant Proof Score Generator (IPSG). Three security properties are formally verified with respect to an unbounded number of protocol participants and protocol executions by employing IPSG to produce their formal proofs, the so- called proof scores in CafeOBJ. With another property, namely authentication, we find a counterexample against it, and then we propose to slightly revise the protocol. With the improved version, we formally verify that the authentication property is enjoyed, while the three properties remain secure. To model the presence of malicious participants, we extend the Dolev-Yao intruder, which is the standard intruder model used in security protocol analysis/verification, because the availability assumption of large-scale quantum computers gives the attacker some new capabilities. Under our threat model, the intruder is given capabilities of fully controlling the network as the Dolev-Yao intruder, and additionally breaking ECDH’s security as well as compromising secrets.

The global poultry industry, as a leading producer of animal protein, faces significant challenges related to animal health and production due to high bird density and disease risks. A major concern is the Avian Respiratory Complex (ARC), a multifactorial health issue involving pathogens such as avian metapneumovirus (aMPV), an often-underdiagnosed component of the ARC. Wild birds are seen as reservoirs and spreaders of the virus. This study aimed to detect the presence and subtypes of aMPV in samples from breeders, broilers, laying hens, and wild birds in Colombia. A total of 273 samples, including swabs from the upper respiratory and reproductive tracts, were collected from commercial poultry and wild birds. Using nested RT-PCR targeting the G gene, aMPV subtype B was identified in 23 samples (8.42%). Sequencing revealed high genetic similarity to vaccine strains, classifying all viruses as vaccine-like. In the commercial birds, aMPV-B appeared in 21 samples, regardless of symptoms, often in tests for other ARC agents, indicating diagnostic bias. In the wild birds, two samples tested positive, suggesting potential transmission between wild and domestic birds. These findings highlight the need for broader diagnostics and further research into aMPV’s impact on avian health.

Introducción. Los datos epidemiológicos de la diverticulitis en Colombia son limitados. El objetivo de este artículo fue caracterizar una población que ingresó con diverticulitis aguda al Hospital Universitario San Vicente Fundación, un centro de referencia de la ciudad de Medellín, Colombia, para analizar la presentación y comportamiento de la enfermedad en la población local, con estadísticas propias y desenlaces de la enfermedad en los últimos años. Métodos. Estudio observacional retrospectivo, descriptivo, entre enero de 2015 y diciembre de 2019. Se hizo un estudio exploratorio uni-, bi- y multivariado de factores de riesgo para fallo en el tratamiento y la mortalidad. Resultados. Se incluyeron 103 pacientes. Se presentó principalmente en mujeres y la edad promedio fue de 65 años. La diverticulitis Hinchey Ia fue la más frecuente (41,7 %) y el manejo médico fue exitoso en todos los casos, mientras que en las tipo III y IV, todos se manejaron de forma quirúrgica, con tasas de éxito entre el 50 y el 64 %. La presencia de signos de irritación peritoneal al examen físico, el recuento de leucocitos y la PCR, el ingreso a la Unidad de Cuidados Intensivos y la mortalidad aumentaron de forma directamente proporcional con el estadio de Hinchey. Conclusiones. Existe una relación directamente proporcional entre la clasificación de Hinchey y los signos de respuesta inflamatoria clínicos y paraclínicos, la necesidad de manejo quirúrgico, la estancia en la Unidad de Cuidados Intensivos y la mortalidad.

The nematode Caenorhabditis elegans (C. elegans) is of significant interest for research into neurodegenerative diseases, aging, and drug screening. However, conducting these assays manually is a tedious and time-consuming process. This paper proposes a methodology to achieve a generalist C. elegans detection algorithm, as previous work only focused on dataset-specific detection, tailored exclusively to the characteristics and appearance of the images in a given dataset. The main aim of our study is to achieve a solution that allows for robust detection, regardless of the image-capture system used, with the potential to serve as a basis for the automation of numerous assays. These potential applications include worm counting, worm tracking, motion detection and motion characterization. To train this model, a dataset consisting of a wide variety of appearances adopted by C. elegans has been curated and dataset augmentation methods have been proposed and evaluated, including synthetic image generation. The results show that the model achieves an average precision of 89.5% for a wide variety of C. elegans appearances that were not used during training, thereby validating its generalization capabilities.

This article presents a security formal analysis of the hybrid post-quantum Transport Layer Security (TLS) protocol, a quantum-resistant version of the TLS protocol proposed by Amazon Web Services as a precaution in dealing with future attacks from quantum computers. In addition to a classical key exchange algorithm, the proposed protocol uses a post-quantum key encapsulation mechanism, which is believed invulnerable under quantum computers, so the protocol’s key negotiation is called the hybrid key exchange scheme. One of our assumptions about the intruder’s capabilities is that the intruder is able to break the security of the classical key exchange algorithm by utilizing the power of large quantum computers. For the formal analysis, we use Maude-NPA and a parallel version of Maude-NPA (called Par-Maude-NPA) to conduct experiments. The security properties under analysis are (1) the secrecy property of the shared secret key established between two honest principals with the classical key exchange algorithm, (2) a similar secrecy property but with the post-quantum key encapsulation mechanism, and (3) the authentication property. Given the time limit T = 1,722 h (72 days), Par-Maude-NPA found a counterexample of (1) at depth 12 in T, while Maude-NPA did not find it in T. At the same time T, Par-Maude-NPA did not find any counterexamples of (2) and (3) up to depths 12 and 18, respectively, and neither did Maude-NPA. Therefore, the protocol does not enjoy (1), while it enjoys (2) and (3) up to depths 12 and 18, respectively. Subsequently, the secrecy property of the master secret holds for the protocol up to depth 12.

Communication and information technologies shape the world’s systems of today, and those systems shape our society. The security of those systems relies on mathematical problems that are hard to solve for classical computers, that is, the available current computers. Recent advances in quantum computing threaten the security of our systems and the communications we use. In order to face this threat, multiple solutions and protocols have been proposed in the Post-Quantum Cryptography project carried on by the National Institute of Standards and Technologies. The presented work focuses on defining a formal framework in Maude for the security analysis of different post-quantum key encapsulation mechanisms under assumptions given under the Dolev-Yao model. Through the use of our framework, we construct a symbolic model to represent the behaviour of each of the participants of the protocol in a network. We then conduct reachability analysis and find a man-in-the-middle attack in each of them and a design vulnerability in Bit Flipping Key Encapsulation. For both cases, we provide some insights on possible solutions. Then, we use the Maude Linear Temporal Logic model checker to extend the analysis of the symbolic system regarding security, liveness and fairness properties. Liveness and fairness properties hold while the security property does not due to the man-in-the-middle attack and the design vulnerability in Bit Flipping Key Encapsulation.

Summary: Background: The impact of the COVID-19 vaccination campaign in the US has been hampered by a substantial geographical heterogeneity of the vaccination coverage. Several studies have proposed vaccination hesitancy as a key driver of the vaccination uptake disparities. However, the impact of other important structural determinants such as local disparities in healthcare capacity is virtually unknown. Methods: In this cross-sectional study, we conducted causal inference and geospatial analyses to assess the impact of healthcare capacity on the vaccination coverage disparity in the US. We evaluated the causal relationship between the healthcare system capacity of 2417 US counties and their COVID-19 vaccination rate. We also conducted geospatial analyses using spatial scan statistics to identify areas with low vaccination rates. Findings: We found a causal effect of the constraints in the healthcare capacity of a county and its low-vaccination uptake. Counties with higher constraints in their healthcare capacity were more probable to have COVID-19 vaccination rates ≤50, with 35% higher constraints in low-vaccinated areas (vaccination rates ≤ 50) compared to high-vaccinated areas (vaccination rates > 50). We also found that COVID-19 vaccination in the US exhibits a distinct spatial structure with defined “vaccination coldspots”. Interpretation: We found that the healthcare capacity of a county is an important determinant of low vaccine uptake. Our study highlights that even in high-income nations, internal disparities in healthcare capacity play an important role in the health outcomes of the nation. Therefore, strengthening the funding and infrastructure of the healthcare system, particularly in rural underserved areas, should be intensified to help vulnerable communities. Funding: None.

Facing the potential threat raised by quantum computing, a great deal of research from many groups and industrial giants has gone into building public-key post-quantum cryptographic primitives that are resistant to the quantum attackers. Among them, there is a large number of post-quantum key encapsulation mechanisms (KEMs), whose purpose is to provide a secure key exchange, which is a very crucial component in public-key cryptography. This paper presents a formal security analysis of three lattice-based KEMs including Kyber, Saber, and SK-MLWR. We use Maude, a specification language supporting equational and rewriting logic and a high-performance tool equipped with many advanced features, such as a reachability analyzer that can be used as a model checker for invariant properties, to model the three KEMs as state machines. Because they all belong to the class of lattice-based KEMs, they share many common parts in their designs, such as polynomials, vectors, and message exchange patterns. We first model these common parts and combine them into a specification, called base specification. After that, for each of the three KEMs, by extending the base specification, we just need to model some additional parts and the mechanism execution. Once completing the three specifications, we conduct invariant model checkings with the Maude search command, pointing out a similar man-in-the-middle attack. The occurrence of this attack is due to the fact that authentication is not part of the KEMs, and therefore an active attacker can modify all communication between two honest parties.

Introduction: Retroperitoneal hematomas are rare complications of radical inguinal orchiectomy. This case report discusses their radiological differential diagnosis and management. Case presentation: A radical inguinal orchiectomy was performed on a 27-year-old patient. After discharge, he referred back pain. Computed tomography showed a retroperitoneal hematoma. A conservative approach was decided. Discussion: Traditionally, retroperitoneal hematomas have been considered possible radiologic pitfalls, which has therapeutical implications. This pitfall seems less likely in contemporary clinical practice.A conservative approach is preferred in stable patients, whereas active management should be offered to unstable patients. Conclusion: Future studies are necessary to offer evidence-based therapeutical options.

Objectives: Evidence regarding demand trends for erectile dysfunction (ED) treatments are scarce in South America. This study aims to evaluate trends in ED treatments in Chile over a 10-year period (2010- 2020) and estimate the potential number of candidates for penile prosthesis. Materials and methods: Sales trends of pharmacological treatments and penile prosthesis were obtained from market studies. The potential number of candidates for penile prosthesis implantation was calculated by crossing epidemiological data with previously reported ED prevalence, proportion of sexually active men, percentage of men seeking medical assistance for ED, and the proportion of patients who are non-responders to ED oral drug therapies Results: In the 10-year studied period, the Chilean male population older than 50 years increased 34.7%, with an average annual variation (AAV) of 3.4%. For the same period, the sales of oral drug therapies for ED increased by 71.3% (AAV 6.2%), the sales of intracavernosal vasoactive agents (ICVA) decreased by 0.4% (AAV -0.2%), and penile prosthesis sales increased by 113% (AAV 6.7%). We estimated that only 0.05% of sexually active men older than 50 years old with ED who sought medical assistance finally had a penile prosthesis implanted to manage their condition. Conclusions: Demand for ED oral drug therapies significantly increased in Chile during the last decade, while ICVA remained stable. The annual rate of penile prosthesis implantation increased. However, the gap between the potential penile prosthesis candidates and the actual number of devices implanted is suspected to remain extremely high.

Partial evaluation (PE) is a branch of computer science that achieves code optimization via specialization. This article describes a PE methodology for optimizing rewrite theories that encode concurrent as well as nondeterministic systems by means of the Maude language. The main advantages of the proposed methodology can be summarized as follows: • An automatic program optimization technique for rewrite theories featuring several PE criteria that support the specialization of a broad class of rewrite theories. • An incremental partial evaluation modality that allows the key specialization components to be encapsulated at the desired granularity level to facilitate progressive refinements of the specialization. • All executability theory requirements are preserved by the PE transformation. Also the transformation ensures the semantic equivalence between the original rewrite theory and the specialized theory under rather mild conditions.

Equational unification of two terms consists of finding a substitution that, when applied to both terms, makes them equal modulo some equational properties. Equational unification is of special relevance to automated deduction, theorem proving, protocol analysis, partial evaluation, model checking, etc. Several algorithms have been developed in the literature for specific equational theories, such as associative-commutative symbols, exclusive-or, Diffie-Hellman, or Abelian Groups. Narrowing was proved to be complete for unification and several cases have been studied where narrowing provides a decidable unification algorithm. A new narrowing-based equational unification algorithm relying on the concept of the variants of a term has been developed and it is available in the most recent version of Maude, version 2.7.1, which provides quite sophisticated unification features. A variant of a term t is a pair consisting of a substitution sigma and the canonical form of tsigma. Variant-based unification is decidable when the equational theory satisfies the finite variant property. However, it may compute many more unifiers than the necessary and, in this paper, we explore how to strengthen the variant-based unification algorithm implemented in Maude to produce a minimal set of most general variant unifiers. Our experiments suggest that this new adaptation of the variant-based unification is more efficient both in execution time and in the number of computed variant unifiers than the original algorithm available in Maude.

Objetivo. Desarrollar una nueva metodología para caracterizar la estructura del eritrocito normal mediante el espacio ocupado por el anillo del eritrocito normal caracterizado con el método de Box Counting. Método. se analizaron las imágenes de 20 extendidos de sangre periférica, cuyos eritrocitos fueron evaluados por un experto como normales. Se superpusieron dos rejillas Kp de 5 x 5 pixeles y Kg de 10 x 10 pixeles, para calcular el espacio ocupado por dos regiones del eritrocito estos son, el disco y centro de este, visto de manera frontal mediante el método de Box Counting. Resultados. Los espacios ocupados por la región del disco con la rejilla Kp variaron entre 47 y 56, la región del centro del eritrocito, varió entre 9 y 14. La dimensión fractal de estas dos regiones varió entre 0,941 y 1,115 para el disco, entre 0,652 y 1,222 para el centro. Conclusiones. La estructura del eritrocito normal puede ser caracterizada mediante el espacio ocupado por cada una de las regiones del eritrocito a partir de la geometría fractal.

From the Marxist conception of society, violence is not a phenomenon that is advocated per se, but to understand the historical-social development, it is perceived that violence, as class societies, has played a decisive role for the configuration, consolidation and decline of the same. Reject this approach both reactionary violence and abstract pacifism and recognize revolutionary violence as the only form of radical transformation of society, which will be necessary at some particular moment in history to end the capitalist mode of production, and thus, give to a new social formation that encourages the transition towards a communist society.

En este trabajo se empleó el proceso de soldadura en estado sólido Friction Stir Welding (FSW), aprovechando su condición para obtener uniones permanentes sin superar la temperatura de fusión de los materiales involucrados y sin requerir material de aporte. Sus características lo convierten en una buena opción para la obtención de juntas disímiles y específicamente para la combinación AA 7075 – T6 y polietileno de alta densidad (HDPE, por sus siglas en inglés). Esta aleación es comúnmente empleada en el sector aeroespacial, y es ideal para el proceso FSW, ya que se caracteriza por su baja soldabilidad por métodos tradicionales por fusión, al presentar problemas de susceptibilidad al agrietamiento durante la solidificación. Las uniones polímero-aluminio se presentan como una alternativa para la fabricación de componentes que requieren altas relaciones resistencia–peso. Para las juntas se empleó material base de 50 x 150 mm y 3/16 in de espesor, una maquina CNC equipada con un dispositivo de medición de fuerzas, axiales y longitudinales, adaptado a la bancada; una herramienta no consumible de acero H13 con hombro convexo de círculos concéntricos, y un pin cilíndrico roscado de 4,5 mm de largo. Los parámetros evaluados estuvieron entre 500 y 2450 rpm de velocidad de giro, y entre 25 y 100 mm/min para la velocidad de avance. Las juntas obtenidas se evaluaron empleando ensayos no destructivos (END) de inspección visual (IV) y líquidos penetrantes (LP). Adicionalmente se empleó corte por chorro de agua y partículas, buscando así el menor nivel de afectación, para obtener probetas y comparar el nivel de continuidad o unión en la sección transversal de las juntas, empleando estereoscopia óptica. Como complemento de las técnicas de inspección, se contrastaron los resultados con datos de fuerza longitudinal y axial y el comportamiento mecánico de algunas juntas. A partir de los resultados obtenidos por los métodos mencionados se encontró que ante valores intermedios de velocidades de rotación y de avance en el intervalo evaluado, la sección transversal de las soldaduras presenta mayor continuidad y mejores prestaciones. Resalta la combinación de parámetros: soldaduras a 50 mm/min, entre 1150 a 2450 RPM, y la combinación de 75 mm/min y 2450 RPM. La obtención de juntas sanas es prometedora, pero aún está en desarrollo.

Friction stir welding (FSW) is a process originally developed for joining light materials, such as aluminum and magnesium, as an answer to their poor weldability by conventional fusion processes. In Colombia, the technique has been studied but its industrial implementation is uncommon, due to the high cost of specialized machinery and the unfamiliarity with the technique of local industries. This article presents an implementation case study of FSW on a 6082-aluminum alloy train component from Metro de Medellín (MdM), aiming to establish the component design changes required to accommodate the FSW process, and conventional machines available in the local area which may be available for welding. Additionally, a simple comparison was made between the cost of this approach versus the manufacturing strategy currently used for the selected component. Initially, welding forces were measured when performing the seam on the selected component using an FSW machine. This data was then used to downselect the local milling machines with these capabilities. A simple but specific tool was designed for the geometry of one of the component features. Finally, a prototype was fabricated, and weld samples were obtained, polished, etched, and examined using a microhardness machine and an optical microscope. Results show a good opportunity for the execution of simple components with uniform geometries, which can be carried out using locally available machinery because they do not surpass their maximum loading capacity, the welds do not present visible discontinuities, and an average hardness of 69.5 HV and mechanical efficiency of 95% can be achieved. Additionally, the manufacturing process is around 30% cheaper compared to traditional methods, making the application viable, economically speaking.

‘Ciudadelas en los conflictos” es una tesis de Maestría que quiere mostrar cómo el proceso conceptual de la fotografía va de la realidad a la representación por modelos, pero también cómo las representaciones de estos modelos adquieren un nuevo significado, la realidad de virtualismo y la ilusión. Usar instalaciones o interactuar con modelos es inventar imaginarios, o llamar memorias, que podrían ser puestos sobre una base tangible para fotografiarlas después. Quiero reflexionar sobre ciudades imaginarias y la utopía de la guerra y el desplazamiento, imaginando cada foto como una ciudadela. Los modelos construidos que acompañan este texto se entienden como fortalezas, ya que incluyen, a veces al azar, todas las variables sociales, culturales y físicas que las ciudades tienen, como “imitación de la vida”. Una metáfora de las variadas e irónicas miradas de un desplazado, se podrían obtener al llegar a las ciudades o a los lugares urbanos. Por lo tanto, el ciudadano inesperado vive dentro de una ciudadela en el conflicto. El fenómeno de la guerra y el desplazamiento forzado son la cartografía de las nuevas ciudades en Colombia, que se registran en esta obra de una manera triste y satirizada.

Resumen: Este proyecto presenta la evaluación de confiabilidad de los sistemas de distribución con penetración de generación distribuida de las empresas CNEL EP – EL ORO y EMELNORTE S.A. Para ello se realizará un modelado de la red a nivel de troncal, considerando a los ramales de la red como cargas concentradas y estableciendo el escenario de estudio a demanda media. Mediante el software DIgSILENT Power Factory 14.1.3 con su módulo de confiabilidad se determina los índices de confiabilidad de cada alimentador con y sin la penetración de generación distribuida, luego se realiza una comparación y análisis de resultados obtenidos, sugiriendo además donde sea posible, la ubicación de un punto de conexión adicional para los generadores y/o inserción de equipos de seccionamiento a nivel de troncal para la creación de tramos; con propósitos de tener una idea de cómo mejoraría la confiabilidad de la red con las adecuaciones mencionadas. Abstract: The objective of this project is to evaluate the systems distribution reliability with distributed generators about two electric enterprises such as CNEL EP – EL ORO and EMELNORTE SA. For this purpose, the networks will be modeled at the level of trunk considering the branch network as concentrated loads and setting the scene of study in average demand. By DIgSILENT 14.1.3 Power Factory software with reliability analysis module, the reliability indices of each feeder is determined “with and without” penetration of distributed generation. Then make a comparison and analysis of results, also if it is possible, an additional connection point is suggested for distributed generators and / or insertion of switching equipment at the level of trunk to create sections, to have an idea of how improve network reliability with the adjustments mentioned

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El presente trabajo pretende servir como introducción a una teodicea de la filosofía y la teología racionalista (mu`tazilí) árabe a partir de un texto de Algazel. Esta teología y filosofía cree que Dios ha creado el mejor de los mundos posibles debido a su esencia buena, siendo, por tanto, optimista y determinista. Sin embargo, este optimismo en la teología viene dado por la mera voluntad de Dios, mientras que en la filosofía por la causalidad y la necesidad lógica.

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