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The aim of this paper is to derive a system of two renewal equations from individual-level assumptions concerning a cyclin-structured cell population. Nonlinearity arises from the assumption that the rate at which quiescent cells become proliferating is determined by feedback. In fact, we assume that this rate is a nonlinear function of a weighted population size. We characterize steady states and establish the validity of the principle of linearized stability

Computing Efficient Financial Strategies: An Extended Compromise Programming Approach

This paper proposes a mathematical model to plan the financial strategy of a large company. The model links the philosophy of new behavioural economics with the multiple criteria decision making paradigm. Within this theoretical approach, the proposed model is supported by more realistic behavioral hypotheses. After formulating the initial multi-objective programming model, it has, due to its underlying computational difficulties, to be transformed into an easily computable extended compromise programming model. The functional and empirical potential of the model is illustrated with the help of a case study concerning a “stock market quoted” Spanish company operating in the energy sector. This paper shows how such an approach can open up new prospects for research linking economic problems with applied mathematic

Discovery of magnetic fields in central stars of planetary nebulae

For the first time we have directly detected magnetic fields in central stars of planetary nebulae by means of spectro-polarimetry with FORS1 at the VLT. In all four objects of our sample we found kilogauss magnetic fields, in NGC1360 and LSS1362 with very high significance, while in EGB5 and Abell36 the existence of a magnetic field is probable but with less certainty. This discovery supports the hypothesis that the non-spherical symmetry of most planetary nebulae is caused by magnetic fields in AGB stars. Our high discovery rate demands mechanisms to prevent full conservation of magnetic flux during the transition to white dwarfs.Comment: 8 pages, 4 figures, Accepted for Publication by Astronomy & Astrophysics See also press release by A&A on their homepage www.edpsiences.or

Heart Failure in Acute Ischemic Stroke

Heart failure (HF) is a complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood. Due to the aging of the population it has become a growing public health problem in recent decades. Diagnosis of HF is clinical and there is no diagnostic test, although some basic complementary testing should be performed in all patients. Depending on the ejection fraction (EF), the syndrome is classified as HF with low EF or HF with normal EF (HFNEF). Although prognosis in HF is poor, HFNEF seems to be more benign. HF and ischemic stroke (IS) share vascular risk factors such as age, hypertension, diabetes mellitus, coronary artery disease and atrial fibrillation. Persons with HF have higher incidence of IS, varying from 1.7% to 10.4% per year across various cohort studies. The stroke rate increases with length of follow-up. Reduced EF, independent of severity, is associated with higher risk of stroke. Left ventricular mass and geometry are also related with stroke incidence, with concentric hypertrophy carrying the greatest risk

Transcription factor NFE2L2/NRF2 is a regulator of macroautophagy genes

Autophagy is a highly coordinated process that is controlled at several levels including transcriptional regulation. Here, we identify the transcription factor NFE2L2/NRF2 (nuclear factor, erythroid 2 like 2) as a regulator of autophagy gene expression and its relevance in a mouse model of Alzheimer disease (AD) that reproduces impaired APP (amyloid β precursor protein) and human (Hs)MAPT/TAU processing, clearance and aggregation. We screened the chromatin immunoprecipitation database ENCODE for 2 proteins, MAFK and BACH1, that bind the NFE2L2-regulated enhancer antioxidant response element (ARE). Using a script generated from the JASPAR's consensus ARE sequence, we identified 27 putative AREs in 16 autophagy-related genes. Twelve of these sequences were validated as NFE2L2 regulated AREs in 9 autophagy genes by additional ChIP assays and quantitative RT-PCR on human and mouse cells after NFE2L2 activation with sulforaphane. Mouse embryo fibroblasts of nfe2l2-knockout mice exhibited reduced expression of autophagy genes, which was rescued by an NFE2L2 expressing lentivirus, and impaired autophagy flux when exposed to hydrogen peroxide. NFE2L2-deficient mice co-expressing HsAPP(V717I) and HsMAPT(P301L), exhibited more intracellular aggregates of these proteins and reduced neuronal levels of SQSTM1/p62, CALCOCO2/NDP52, ULK1, ATG5 and GABARAPL1. Also, colocalization of HsAPP(V717I) and HsMAPT(P301L) with the NFE2L2-regulated autophagy marker SQSTM1/p62 was reduced in the absence of NFE2L2. In AD patients, neurons expressing high levels of APP or MAPT also expressed SQSTM1/p62 and nuclear NFE2L2, suggesting their attempt to degrade intraneuronal aggregates through autophagy. This study shows that NFE2L2 modulates autophagy gene expression and suggests a new strategy to combat proteinopathies

Pressure pain sensitivity map of multifocal nummular headache:a case report

BACKGROUND: Nummular headache (NH) is most commonly a localized unifocal headache; however, some patients infrequently exhibit multifocal symptomatic painful head areas retaining all features of NH. We present the pressure pain sensitivity map of an adolescent with multifocal NH. CASE PRESENTATION: We describe a case of a 14 year-old-girl with a 3-year history of continuous pain in four rounded areas, all of them with the same size and shape. Pressure pain thresholds (PPT) were assessed on 21 points over the scalp and over the symptomatic areas. A pressure pain sensitivity map of the head was constructed. The neurological exam was unremarkable, with neither sensory symptoms nor trophic changes within the painful areas. As previously shown, symptomatic points exhibited lower PPTs compared to the surrounding areas. The map reflected 4 restricted areas of mechanical hyperalgesia confined just to the painful areas. Treatment with gabapentin achieved complete remission. CONCLUSION: This is the first pain sensitivity map of a patient with multifocal NH. Our results support peripheral mechanisms are maintained in multifocal NH

Relación del sistema de riesgos con el índice de accidentabilidad de la empresa del sub sector hidrocarburos EBH Ingenieros S.A.C.

Analiza la validación de la aplicación del Sistema de Gestión de Riesgo como herramienta o estrategia para mejorar la gestión en la seguridad y la salud ocupacional, que se materializó en la reducción de la accidentabilidad como se aprecia en los resultados logrados lo que se estima y observa en la aplicación en el presente estudio, mediante el análisis directo con la finalidad de considerar como la inserción del control de la gestión del riesgo ha significado un aporte notable para mejorar la gestión de los Planes de Seguridad y Salud: Prevención, Corrección, Respuesta, de tal forma que se ha obtenido un resultado que haga posible la validación de una estrategia para poder reducir la incidencia de los accidentes, contribuyendo con un componente a considerar hacia adelante y un tema o línea de investigación más amplio para la ingeniería de la seguridad y la salud en el trabajo, campo que aún tiene muchas acciones que responder para satisfacer la principal necesidad: mejores condiciones de trabajo

LIPSNN: A Light Intrusion-Proving Siamese Neural Network Model for Facial Verification

Facial verification has experienced a breakthrough in recent years, not only due to the improvement in accuracy of the verification systems but also because of their increased use. One of the main reasons for this has been the appearance and use of new models of Deep Learning to address this problem. This extension in the use of facial verification has had a high impact due to the importance of its applications, especially on security, but the extension of its use could be significantly higher if the problem of the required complex calculations needed by the Deep Learning models, that usually need to be executed on machines with specialised hardware, were solved. That would allow the use of facial verification to be extended, making it possible to run this software on computers with low computing resources, such as Smartphones or tablets. To solve this problem, this paper presents the proposal of a new neural model, called Light Intrusion-Proving Siamese Neural Network, LIPSNN. This new light model, which is based on Siamese Neural Networks, is fully presented from the description of its two block architecture, going through its development, including its training with the well- known dataset Labeled Faces in the Wild, LFW; to its benchmarking with other traditional and deep learning models for facial verification in order to compare its performance for its use in low computing resources systems for facial recognition. For this comparison the attribute parameters, storage, accuracy and precision have been used, and from the results obtained it can be concluded that the LIPSNN can be an alternative to the existing models to solve the facet problem of running facial verification in low computing resource devices

Palinología de los géneros Tarasa y Wissadula (Malvaceae, Malveae) de Argentina

Pollen grains of twenty one species of two genera of Malvaceae were studied and described under optical and scanning microscopy; Tarasa Phil.: T. alberti Phil., T. antofagastana (Phil.) Krapov., T. capitata (Cav.) D. M. Bates, T. heterophylla(Griseb.) Krapov., T. humilis (Gill. ex Hook & Arn.) Krapov., T. meyeri Krapov., T. odonellii Krapov., T. tarapacana (Phil.) Krapov., T. tenella (Cav.) Krapov., T. trisecta(Griseb.) Krapov., T. urbaniana (Ulbr.) Krapov., and Wissadula Medik: W. decora S. Moore, W densiflora R.E.Fr., W. glechomaefolia (A. St.-Hil.) R.E.Fr., W. gymnanthemum (Griseb.) K. Schum., W. paraguariensis Chodat, W. parviflora(A.St.-Hil.) R.E.Fr., W. setifera Krapov., W. subpeltata (Kuntze) R.E.Fr., W. tucumanensis R.E.Fr. and W. wissadifolia (Griseb.) Krapov. They showed differences at generic level, excepting Tarasa alberti which has affinities with theWissadula group. Pollen grains are spheroidal, oblate-spheroidal and suboblate, medium to large sized. The apertures show variations in number (three to eight), but all they are colporate and have different distribution patterns: zonocolporate and spiralloid. The sculpture does not show marked differences on the surface; the most of them are echinate, echinulate with nanospinulae and perforations (foveas) between the spines or spinulae. Two keys to determine the species of each genus and distinguish the three recognized pollen types are given: 1) tri-tetracolporate, 2) pentazonocolporate and 3) oligocolporate (6-8 apertures) spiraloid arrangement.Fueron estudiados y descriptos con microscopio óptico y electrónico de barrido, los granos de polen de veintiún especies pertenecientes a dos géneros de Malvaceae; Tarasa Phil.: T. alberti Phil., T. antofagastana (Phil.) Krapov., T. capitata(Cav.) D. M. Bates, T. heterophylla (Griseb.) Krapov., T. humilis (Gillies ex Hook & Arn.) Krapov., T. meyeri Krapov., T. odonellii Krapov., T. tarapacana (Phil.) Krapov.,T. tenella (Cav.) Krapov., T. trisecta (Griseb.) Krapov. y T. urbaniana (Ulbr.) Krapov., yWissadula Medik: W. decora S. Moore, W. densiflora R. E. Fr., W. glechomaefolia (A. St.-Hil.) R. E. Fr., W. gymnanthemum (Griseb.) K.Schum., W. paraguariensisChodat, W. parviflora (A.St.-Hil.) R.E.Fr., W. setifera Krapov., W. subpeltata (Kuntze) R.E.Fr., W. tucumanensis R.E.Fr. y W. wissadifolia (Griseb.) Krapov. Existe diferencia entre ambos géneros, con excepción de Tarasa alberti que tiene más afinidad con el grupo Wissadula. Los granos de polen son esferoidales, oblato-esferoidales y suboblatos, de medianos a grandes; la escultura no muestra gran variabilidad, las especies de ambos géneros son equinadas o equinuladas con nanoespínulas y perforaciones (fóveas) entre las espinas o espínulas. En el género Tarasa las aperturas muestran variación en el número (tres a ocho) y en la distribución: zonocolporadas, y en posición espiraloide. Las especies deWissadula son todas trizonocolporadas. Se presentan dos claves para reconocer las especies de cada género y se establecen tres tipos de polen en base al número y distribución de las aperturas: 1) tri-tetrazonocolporado, 2) pentazonocolporado y 3) oligocolporado (6 a 8 aperturas) en posición espiraloide