Non-concave utility maximisation on the positive real axis in discrete time

We treat a discrete-time asset allocation problem in an arbitrage-free, generically incomplete financial market, where the investor has a possibly non-concave utility function and wealth is restricted to remain non-negative. Under easily verifiable conditions, we establish the existence of optimal portfolios.Comment: 20 page

Distribución de hembras adultas de merluza (Merluccius hubbsi) en diferentes estadios de madurez durante el otoño y la primavera de 2012, en la Zona Común de Pesca Argentino- Uruguaya

En el presente trabajo se analizó la distribución de las hembras adultas de merluza común del stock norteño en diferentes estadios de madurez, durante el otoño y la primavera de 2012. El material biológico fue obtenido en la Zona Común de Pesca Argentino-Uruguaya (ZCPAU) durante dos campañas de investigación realizadas por el Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) en mayo y noviembre de dicho año. Se seleccionaron ovarios de hembras adultas muestreadas al azar (710 en otoño y 531 en primavera) en distintos lances de pesca. Los resultados obtenidos a partir de submuestras histológicas de gónadas de hembras adultas mostraron una alta proporción de hembras reproductivamente activas dentro de la población adulta durante el mes de mayo, con un bajo porcentaje de ejemplares en post-desove y reposo en el sector analizado. Esta composición de estadios es característica de un grupo en plena actividad reproductiva. Mientras que en el mes de noviembre se observó una situación opuesta, con altos porcentajes en reposo y maduración temprana, y muy poca presencia de hembras en plena actividad reproductiva, siendo esto característico de un final de periodo de puesta.Fil: Rodrigues, Karina Andrea. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Estrada, M.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Brachetta, H. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentin

An open‑source low‑cost sensor for SNR‑based GNSS reflectometry : design and long‑term validation towards sea‑level altimetry

Monitoring sea level is critical due to climate change observed over the years. Global Navigation Satellite System Reflectometry (GNSS-R) has been widely demonstrated for coastal sea-level monitoring. The use of signal-to-noise ratio (SNR) observations from ground-based stations has been especially productive for altimetry applications. SNR records an interference pattern whose oscillation frequency allows retrieving the unknown reflector height. Here we report the development and validation of a complete hardware and software system for SNR-based GNSS-R. We make it available as open source based on the Arduino platform. It costs about US$200 (including solar power supply) and requires minimal assembly of commercial off-the-shelf components. As an initial validation towards applications in coastal regions, we have evaluated the system over approximately 1 year by the Guaíba Lake in Brazil. We have compared water-level altimetry retrievals with independent measurements from a co-located radar tide gauge (within 10 m). The GNSS-R device ran practically uninterruptedly, while the reference radar gauge suffered two malfunctioning periods, resulting in gaps lasting for 44 and 38 days. The stability of GNSS-R altimetry results enabled the detection of miscalibration steps (10 cm and 15 cm) inadvertently introduced in the radar gauge after it underwent maintenance. Excluding the radar gaps and its malfunctioning periods (reducing the time series duration from 317 to 147 days), we have found a correlation of 0.989 and RMSE of 2.9 cm in daily means. To foster open science and lower the barriers for entry in SNR-based GNSS-R research and applications, we make a complete bill of materials and build tutorials freely available on the Internet so that interested researchers can replicate the system

Development and Characterization of Thirteen Microsatellite Markers for the Longbill Spearfish (Tetrapturus pfluegeri)

The longbill spearfish (Tetrapturus pfluegeri; Istiophoridae) is an epipelagic billfish species broadly distributed in the Atlantic Ocean and exploited by multinational fisheries. No data exist on the population structure or genetic diversity of this apex predator, despite a strong need for this information to inform international conservation and management efforts. Thirteen microsatellite loci, comprising mostly tri- and tetra-nucleotide repeats, were isolated and characterized for this species by genotyping individuals (n = 29–42) obtained from western North and South Atlantic fisheries. The average number of alleles ranged from 3 to 16 and the expected heterozygosity ranged from 0.35 to 0.86. This suite of markers provides the first population genetic nuclear resources for the longbill spearfish, allowing initiation of studies for assessing the population structure and demography of this poorly understood species

Caracterização dos recém-nascidos com hidropisia fetal não imune admitidos em uma unidade neonatal de terapia intensiva

PURPOSE: To determine the incidence and characteristics of nonimmune hydrops fetalis in the newborn population. METHOD: A retrospective study of the period between 1996 and 2000, including all newborns with a prenatal or early neonatal diagnosis of nonimmune hydrops fetalis, based on clinical history, physical examination, and laboratory evaluation. The following were analyzed: prenatal follow-up, delivery type, gender, birth weight, gestational age, presence of perinatal asphyxia, nutritional classification, etiopathic diagnosis, length of hospital stay, mortality, and age at death. RESULTS: A total of 47 newborns with hydrops fetalis (0.42% of live births), 18 (38.3%) with the immune form and 29 (61.7%) with the nonimmune form, were selected for study. The incidence of nonimmune hydrops fetalis was 1 per 414 neonates. Data was obtained from 21 newborns, with the following characteristics: 19 (90.5%) were suspected from prenatal diagnosis, 18 (85.7%) were born by cesarean delivery, 15 (71.4%) were female, and 10 (47.6%) were asphyxiated. The average weight was 2665.9 g, and the average gestational age was 35 3/7 weeks; 14 (66.6%) were preterm; 18 (85.0 %) appropriate delivery time; and 3 (14.3%) were large for gestational age. The etiopathic diagnosis was determined for 62%, which included cardiovascular (19.0%), infectious (9.5%), placental (4.8%), hematologic (4.7%), genitourinary (4.8%), and tumoral causes (4.8%), and there was a combination of causes in 9.5%. The etiology was classified as idiopathic in 38%. The length of hospital stay was 26.6 ± 23.6 days, and the mortality rate was 52.4%. CONCLUSIONS: The establishment of a suitable etiopathic diagnosis associated with prenatal detection of nonimmune hydrops fetalis can be an important step in reducing the neonatal mortality rate from this condition.OBJETIVOS: Determinar a incidência e caracterizar a população de recém-nascidos com hidropisia fetal não imune. MÉTODO: Estudo retrospectivo, referente ao período de 1996 a 2000, incluindo todos os recém-nascidos com diagnóstico antenatal ou neonatal, com base na história clínica, exame físico e avaliação laboratorial. Foram analisados: seguimento pré-natal, tipo de parto, sexo, peso de nascimento, idade gestacional, presença de asfixia perinatal, classificação nutricional, diagnóstico etiopatogênico, tempo de internação, mortalidade, idade do óbito. RESULTADOS: Foram selecionados 47 recém-nascidos com hidropisia fetal (0,42% dos nascidos vivos), 18 (38,3%) com a forma imune e 29(61,7%) com a não imune. A incidência de hidropisia fetal não imune foi de 1:414 nascidos vivos. Obtiveram-se dados de 21 recém-nascidos destes, 19 (90,5%) apresentavam suspeita diag nostico antenatal, 18 (85,7%) nasceram de parto cesariano; 15 (71,4%) eram do sexo feminino; 10 (47,6%) foram asfixiados. O peso médio foi 2665,9g, e a idade gestacional média de 35 3/7 sem, 14 (66,6%) pré-termo; 18 (85,7%) adequados e 3 (14,3%) grandes para idade gestacional. O diagnóstico etiopatogênico foi realizado em 62% dos recém-nascidos, sendo decorrente de causas cardiovasculares (19%), infecciosas (9,5%), placentária (4,76%), hematológicas (4,76,%), gênito-urinária (4,76%), tumoral (4,76%) e houve associação de causas em 9,5%. A etiologia foi classificada em idiopática em 38%. O tempo de internação foi de 26,6 dias ± 23,6 e a mortalidade de 52,4%. CONCLUSÕES: O estabelecimento de um correto diagnóstico etiopatogênico, associado à detecção antenatal da hidropisia fetal não imune, constitui elemento importante para uma redução da mortalidade neonatal decorrente desta grave doença

Fracture characterisation of bone-cement bonded joints under mode I loading

Over the years, many techniques have been developed for the stabilisation of bone fractures. The study of the adhesion of bone-to-bone cement is an important step towards the development of new immobilization systems. Although bone cement has been used for more than fifty years, very few studies have been performed regarding the evaluation of fracture properties. In this work, numerical and experimental investigations were conducted to evaluate the strain energy release rate under mode I loading in a bone-cement bonded joint, using the Double Cantilever Beam (DCB) test. Cohesive zone laws were also measured combining the finite element method with non-linear elastic fracture mechanics. This has been made in a cortical bone bonded joint with poly- methylmethacrylate (PMMA). Consistent results have been obtained regarding fracture toughness in a widely used bone-to-bone cement joint in many biomedical applications.The first author acknowledges the Portuguese (FCT) for the conceded financial support through the reference grant PTDC/EME-SIS/28225/2017. M.F.S.M. de Moura acknowledges the ‘Laboratório Associado de Energia, Transportes e Aeronáutica’ (LAETA) for the financial support by the project UID/EMS/50022/2020. The corresponding author acknowledges FCT for the conceded financial support through the reference projects PTDC/EME-SIS/28225/2017 and UID/EEA/04436/2019.Funding: Portuguese Foundation for Science and Technology for MsC grant of the first author, and research project PTDC/EME-SIS/28225/2017

Osteosynthesis metal plate system for bone fixation using bicortical screws: numerical–experimental characterization

This study reports the numerical and experimental characterization of a standard immobilization system currently being used to treat simple oblique bone fractures of femoral diaphyses. The procedure focuses on the assessment of the mechanical behavior of a bone stabilized with a dynamic compression plate (DCP) in a neutralization function, associated to a lag screw, fastened with surgical screws. The non-linear behavior of cortical bone tissue was revealed through four-point bending tests, from which damage initiation and propagation occurred. Since screw loosening was visible during the loading process, damage parameters were measured experimentally in independent pull-out tests. A realistic numerical model of the DCP-femur setup was constructed, combining the evaluated damage parameters and contact pairs. A mixed-mode (I+II) trapezoidal damage law was employed to mimic the mechanical behavior of both the screw–bone interface and bone fractures. The numerical model replicated the global behavior observed experimentally, which was visible by the initial stiffness and the ability to preview the first loading peak, and bone crack satisfactorily.This research was funded by the Portuguese Foundation for Science and Technology (FCT), grant numbers SFRH/BD/143736/2019, UIDB/CVT/00772/2020, LA/P/0059/2020, UIDB/04033/2020, PTDC/EME-SIS/28225/2017, UID/EEA/04436/2019 and Laboratório Associado de Energia, Transportes e Aeronáutica (LAETA), grant number UID/EMS/50022/2020