On approximation of functions satisfying defective renewal equations

Functions satisfying a defective renewal equation arise commonly in applied probability models. Usually these functions don't admit a explicit expression. In this work we consider to approximate them by means of a gamma-type operator given in terms of the Laplace transform of the initial function. We investigate which conditions on the initial parameters of the renewal equation give optimal order of uniform convergence in the approximation. We apply our results to ruin probability in the classical risk model, paying special attention to mixtures of gamma claim amounts

Osteosarcoma extraesquelético. Caso clínico.

El osteosarcoma extraesquelético es un tumor maligno de partes blandas poco frecuente. Es una causa rara de osificación en partes blandas que se distingue de otras entidades por las características clínicas, los estudios de imagen y los exámenes anatomopatológicos. Presentamos un caso clínico en un varón de 64 años, a nivel de muslo. Se realiza una revisión de la bibliografía, señalando las principales características de esta entidad.Extraskeletal osteosarcoma is a rare malignant soft-tissue neoplasm. The clinical feature, imaging studies findings and histologic patterns allow the diferential diagno- sis with other entities. We report a case of a 64 years old man who had this tumour in his thigh. We make a review of litera- ture

Log-concavity of compound distributions with applications in operational and actuarial models

We establish that a random sum of independent and identically distributed (i.i.d.) random quantities has a log-concave cumulative distribution function (cdf) if (i) the random number of terms in the sum has a log-concave probability mass function (pmf) and (ii) the distribution of the i.i.d. terms has a non-increasing density function (when continuous) or a non-increasing pmf (when discrete). We illustrate the usefulness of this result using a standard actuarial risk model and a replacement model.We apply this fundamental result to establish that a compound renewal process observed during a random time interval has a log-concave cdf if the observation time interval and the inter-renewal time distribution have log-concave densities, while the compounding distribution has a decreasing density or pmf. We use this second result to establish the optimality of a so-called (s, S) policy for various inventory models with a stock-out cost coefficient of dimension [$/unit], significantly generalizing the conditions for the demand and leadtime processes, in conjunction with the cost structure in these models. We also identify the implications of our results for various algorithmic approaches to compute optimal policy parameters. Copyrigh

Mesenquimoma fibrocartilaginoso de hueso: caso clínico.

Se presenta un caso clínico de un mesenquimoma fibrocartilaginoso a nivel de tibia proximal. Se trata de una rara entidad anatomopatológica descrita por Dahlin en 1984. La lesión puede ser localmente agresiva y el tratamiento debe ser una resección tumoral amplia. Realizamos una revisión de la bibliografía, señalando las principales características de esta entidad poco frecuente.We report a case of fibrocartilaginous mesenchy- moma of bone located in proximal tibia. This is a rare bone tumor which was described in 1984 by Dahlin. The lesion may be locally aggresive and the treatment must be a wide resec- tion. The pertinent medical literature related to this uncom- mon entity has been reviewed

Endocistectomía como tratamiento quirúrgico de elección en hidatidosis muscular primaria: caso clínico

Se presenta el caso clínico de una hidatidosis muscular primaria localizada a nivel del vasto externo del cuádriceps, describiéndose los hallazgos clínicos, analíticos y de estudios de imagen característicos. Y a propósito del mismo se describe y defiende el tratamiento mediante endocistectomía y albendazol, que permite mantener la funcionalidad completa del músculo. A los dos años de evolución la paciente se encuentra asintomática.We report a case of primary hydatíd disease. It ¡s located in the vastus lateralís of the quadriceps. We describe the clinical, serological and radiological features of this dísease. And then we argüe for the use of the surgical endocystectomy and albendazol as the best treatment; thinking that this allows to sustain the complete function of the muscle. Two years later, the patient is asymptomatic

Pseudotumor tras cirugía de revisión por rotura de cabeza cerámica en una artroplastia total de cadera con par cerámica-cerámica: caso clínico

Se presenta un caso clínico con una importante y precoz metalosis, tan solo tres meses después de la revisión de una artroplastia total de cadera primaria par cerámica-cerámica, en la que se había roto la cabeza cerámica, y en la revisión se sustituyó por un par metal-polietileno. Catorce meses después apareció un pseudotumor causado por la metalosis por rotura de la cabeza metálica, por lo que se realizó una nueva revisión utilizando un par metal-metal preservando el vástago femoral que estaba perfectamente anclado aunque el cono Morse tenía una pequeña agresión. Dos años después de esta última cirugía los resultados son satisfactorios.We report a case presenting an important and early metallosis. Three months after a total hip arthroplasty primary using ceramic-ceramic pair, the patient sustained ceramic head fracture was revised to a metal-on-polyethylene articulation. Fourteen months later, a metallosis pseudotumor caused by the fracture of the metal head was observed. The patient was then revised to a metal-metal pair preserving the femoral component since it was well anchored while the Morse cone connection had a small impact. Two years after the last surgery the results are satisfactory

Necrosis del miembro superior tras administración de drogas vía arterial: caso clínico

La administración de drogas por vía parenteral puede causar complicaciones de variada intensidad que pueden llegar a comprometer la viabilidad no sólo de la extremidad, sino también la vida del paciente. Los mejores resultados terapéuticos se lograrían con un diagnóstico y tratamiento precoces. La amputación del miembro debe reservarse para necrosis establecidas y limitadas del mismo.The injection of drugs can cause complications of varying intensity which can compromise the viability of not only the limb but also the patient's life. The best therapeutic results can be achieved with early diagnosis and treatment. Amputation should be reserved for a demarcated gangrene

Osteosarcoma perióstico: caso clínico

El osteosarcoma perióstico es un sarcoma raro que asienta en la superficie del hueso. Aunque algunos autores lo incluyen en los osteosarcomas yuxtacorticales sus peculiaridades clínicas, radiológicas y anatomopatológicas entre ellos que llevan a diferencias en el tratamiento y pronóstico le otorgan personalidad propia. Presentamos un caso clínico de osteosarcoma perióstico en un varón de 18 años, a nivel de fémur. Se realiza una revisión de la bibliografía, señalando las principales características de esta entidad.Periosteal osteosarcoma is a rare malignant neoplasm located on bone surface. Although some authors include it among juxtacortical osteosarcoma, its clinical feature, imaging studies findings and histologic patterns which lead to differences in the treatment and prognostic, give to it a peculiar identity. We report a case of an 18 years old man who had this tumour in his femur. We do a review of literature

Hiperplasia angiolinfoide con eosinofilia: a propósito de una localización atípica en músculo trapecio

La hiperplasia angiolinfoide con eosinofilia es una patología poco frecuente de presentación clínica inespecífica que lleva a que rara vez se diagnostique antes del estudio histológico. Habitualmente afecta a piel y tejido celular subcutáneo siendo rara la localización extracutánea. Presentamos un caso clínico de una tumoración en una mujer de 46 años localizada a nivel del músculo trapecio; y revisamos las características histopatológicas y de tratamiento de esta patología.Angiolymphoid hyperplasia with eosinophilia is an uncommon condition with non-specific clinical symptoms that needs a histological study to have the diagnosis. Usually this lesion occurs in the skin and the subcutaneous tissue, with extracutaneous affection being rare. We describe a tumour affecting the trapezius muscle in a 40- year-old woman; and we review the histopathologic findings and the treatment of this pathology

Mitigating Electromagnetic Noise When Using Low-Cost Devices in Industry 4.0

[EN] Transitioning toward Industry 4.0 requires major investment in devices and mechanisms enabling interconnectivity between people, machines, and processes. In this article, we present a low-cost system based on the Raspberry Pi platform to measure the overall equipment effectiveness (OEE) in real time, and we propose two filtering mechanisms for electromagnetic interferences (EMIs) to measure OEE accurately. The first EMI filtering mechanism is the database filter (DBF), which has been designed to record sealing signals accurately. The DBF works on the database by filtering erroneous signals that have been inserted in it. The second mechanism is the smart coded filter (SCF), which is used to filter erroneous signals associated with machine availability measurements. We have validated our proposal in several production lines in a food industry. The results show that our system works properly, and that it considerably reduces implementation costs compared with proprietary systems offering similar functions. After implementing the proposed system in actual industrial settings, the results show a mean error (ME) of -0.43% and a root mean square error (RMSE) of 4.85 in the sealing signals, and an error of 0% in the availability signal, thus enabling an accurate estimate of OEE.This work was supported in part by the Government of Aragon and the European Social Fund "Construyendo Europa desde Aragon" under Grant T40_20D Research Group, and in part by the "Ministerio de Ciencia, Innovacion y Universidades, Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad, Proyectos I+D+I 2018," Spain, under Grant RTI2018-096384-B-I00.Herrero, ÁC.; Sangüesa, JA.; Martínez, FJ.; Garrido, P.; Tavares De Araujo Cesariny Calafate, CM. (2021). Mitigating Electromagnetic Noise When Using Low-Cost Devices in Industry 4.0. IEEE Access. 9:63267-63282. https://doi.org/10.1109/ACCESS.2021.3074588S6326763282