TUMORES RAROS EN NIÑOS Y ADOLESCENTES

ResumenLos tumores infrecuentes están definidos como cánceres pediátricos con una incidencia anual <2 casos por millón. Aunque son percibidos como raros, constituyen el 15% de todos los cánceres en menores de 20 años y 30% de todos los tumores de pacientes entre 15 y 19 años.Se han desarrollado proyectos cooperativos nacionales e internacionales pediátricos con el fin de mejorar el manejo clínico y la investigación básica en estos tumores. Revisamos los procesos desarrollados y las dificultades que se han enfrentado, como bajas tasas de registro y participación en bancos de tumores y estudios clínicos. Esta experiencia inicial ha permitido desarrollar estrategias alternativas que permitirían implementar una iniciativa similar para América Latina.La experiencia demuestra la factibilidad de cooperación multidisciplinaria a nivel nacional y sugiere que se pueden realizar estudios internacionales, que aumenten nuestro entendimiento de la biología de estos tumores, mejorando los resultados de tratamiento de niños y adolescentes con cánceres infrecuentes.SummaryAlthough perceived as rare, infrequent tumors, defined as childhood solid malignancies with an annual incidence < 2/million and not considered in other clinical trials, account for 15% of all cancers in patients younger than age 20 and for 30% of all tumors in patients ages 15 to 19.National and international cooperative projects on rare paediatric tumours have been developed to improve the clinical management and basic research on these tumors. We reviewed the process developed and the problems it had to face, as low rates of registration, low levels of participation in tumor banking, and clinical trials. This initial experience has allowed to develop alternative strategies that could help to launch a latinamerican initiative.Experience demonstrates the feasibility of a national multidisciplinary cooperation and suggests that international studies can be performed, increasing our knowledge to understand the biology and improving the treatment results of young patients with rare cancers

Using principles of authentic assessment to redesign written examinations and tests

Tests and examinations are widely used internationally. Despite their pervasiveness, they tend to measure lower order thinking skills in a decontextualized manner at a time when the literature frequently argues for the benefits of a richer, authentic approach to assessment. The focus of this paper is to improve authenticity in test assessment methods through promoting realism, cognitive challenge and evaluative judgement during the planning, administering and following up of assessment tasks. The article builds on a systematic literature review, in which the main principles of authentic assessment were outlined. In this paper, we posit how these principles can be implemented through the three chronological phases of the assessment process: before, during and after the act of assessment

About the Dirac Equation with a δ\delta potential

An elementary treatment of the Dirac Equation in the presence of a three-dimensional spherically symmetric $\delta (r-r_0)$-potential is presented. We show how to handle the matching conditions in the configuration space, and discuss the occurrence of supercritical effects.Comment: 8 pages, 1 postscript figure, Latex, Revise

Behavioural biology of South American domestic camelids: An overview from a welfare perspective

South American domestic camelids (SADC) have played a key role in the culture, economy, food security and livelihoods of ancient and contemporary societies in Andean countries. This is especially due to the capacity of alpacas and llamas to produce fibre and meat under extreme geographic and climatic conditions. In addition, the breeding and use of SADC as fibre, meat, pet and sheep herding animals has become popular in Europe, North America and Oceania. However, research and scientific literature concerning the behaviour and welfare of both species is scarce, dispersed, and with little visibility compared to other species. Therefore, the objective of this literature review is to compile the international scientific literature on the most relevant aspects of the behaviour of llamas and alpacas, especially in terms of practical aspects which could be used to improve their welfare in the many production systems in which they are raised

Three types of shopping precincts. Three different ways to influence the public sphere of neighborhoods

Indexación: Scopus.Considerando que en la teoría urbana el mercado y los espacios públicos están históricamente vinculados, este artículo analiza un mercado, una galería comercial y un centro comercial (mall). El fin es ilustrar los factores que son determinantes para que en Santiago de Chile estas tipologías de comercio adquieran carácter público y puedan contribuir a la esfera pública de la ciudad, al menos dentro de las limitaciones que se derivan de su condición privada. Hasta ahora el debate ha reflexionado extensivamente sobre estas tres tipologías, sin embargo, existen aún pocos estudios que miran la vida pública que tiene lugar en estas diferentes tipologías de manera paralela, considerando que hoy todas ellas están presentes simultáneamente en la ciudad y se disputan su espacio en ella. Esta investigación describe características físicoespaciales y de administración de estos tres casos para aportar a las políticas públicas y el diseño urbano. Se estudia el comercio en relación a la accesibilidad a nivel metropolitano y en cuanto a los diferentes tipos de comercio, que pretenden atraer un público diverso y promueven el carácter público de los espacios.According to urban theory, commerce and public spaces are historically related to each other. Based on this premise, this paper analyzes a market, a shopping center and a mall. The goal of this research is to identify the key factors that turn these shopping precincts into public spaces and contribute to the public sphere in Santiago, Chile, at least within the context of the limitations associated with their private nature. To date, these three typologies have been the focus of intense debate. However, there are few studies of the public life that takes place in these spaces, especially when considering that they coexist simultaneously in the city, claiming a space within it. This research describes the physical-spatial and administrative characteristics of these three cases in order to contribute to the strengthening of public policies in urban design. Likewise, commerce is studied in relation to accessibility patterns at metropolitan level and the types of markets that aim to attract different users and promote the public nature of these spaces.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-83582018000100089&lng=en&nrm=iso&tlng=e

Climate change impact on thermal comfort in Mexico City housing

This is the author accepted manuscript. The final version is available from WEENTECH via the DOI in this record4th International Conference on Energy, Environment and Economics (ICEEE2019), 20-22 August 2019, Edinburgh, ScotlandA two storey terraced house was modelled in ESP-r with a simple window opening control strategy to represent typical dwellings found in Mexico City and the adjoining municipalities. Future weather data was generated for years in this century based on morphing methods developed from the literature and by the authors and a TMY weather file developed from historical data between 1975 to 1989 by WhiteBox Technologies. The population in the region under consideration is a little over 20 million which represents 16% of Mexico’s population. The present day climate is such that air conditioning is rarely used in single family housing. The main cooling strategy in the hottest months (Mid February to mid June) is window opening. This was modelled considering that if the interior temperature was at or above 18°C and the exterior air temperature was below the interior air temperature then windows would be open. The air flow was modelled using the flow network model within ESP-r. It was found that in the latter part of the present century, this strategy would become increasingly ineffective. This is likely to lead to a considerable increase in installed air conditioning in single family dwellings and a consequent increase in electricity demand and consumption leading to a need for substantial investments in electricity transmission and distribution systems in the region to bring in power from distant sources.Engineering and Physical Sciences Research Council (EPSRC)CONACYT-SENER-Sustentabilidad Energética fund Mexic

An alternative approach for robot localization inside pipes using RF spatial fadings

Accurate robot localization represents a challenge inside pipes due to the particular conditions that characterize this type of environment. Outdoor techniques (GPS in particular) do not work at all inside metal pipes, while traditional indoor localization methods based on camera or laser sensors do not perform well mainly due to a lack of external illumination and distinctive features along pipes. Moreover, humidity and slippery surfaces make wheel odometry unreliable. In this paper, we estimate the localization of a robot along a pipe with an alternative Radio Frequency (RF) approach. We first analyze wireless propagation in metallic pipes and propose a series of setups that allow us to obtain periodic RF spatial fadings (a sort of standing wave periodic pattern), together with the influence of the antenna position and orientation over these fadings. Subsequently, we propose a discrete RF odometry-like method, by means of counting the fadings while traversing them. The transversal fading analysis (number of antennas and cross-section position) makes it possible to increase the resolution of this method. Lastly, the model of the signal is used in a continuous approach serving as an RF map. The proposed localization methods outperform our previous contributions in terms of resolution, accuracy, reliability and robustness. Experimental results demonstrate the effectiveness of the RF-based strategy without the need for a previously known map of the scenario or any substantial modification of the existing infrastructure

Uso De Contraceptivos Reversíveis De Longa Duração E A Relação Entre Taxas De Descontinuidade Devido à Menopausa E à Esterilização De Homens E Mulheres

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Introduction Women require effective contraception until they reach menopause. The long acting reversible contraceptives (LARC) and the depot-medroxyprogesterone acetate (DMPA, Depo-Provera®, Pfizer, Puurs, Belgium) are great options and can replace possible sterilizations. Purpose To assess the relationship between the use of LARCs and DMPA and terminations ascribed to menopause and sterilizations in a Brazilian clinic. Methods We reviewed the records of women between 12 and 50 years of age attending the clinic that chose to use a LARCmethod or DMPA. Cumulative termination rates due to sterilization or because the woman had reached menopause were computed using single decrement life-table analysis over 32 years. We also examined all records of surgical sterilization at our hospital between the years 1980-2012. Results Three hundred thirty-two women had continuously used the same contraceptive until menopause, and 555 women had discontinued the method because they or their partners underwent sterilization. Fromyear 20 to year 30 of use, levonorgestrel intrauterine-releasing system (LNG-IUS - Mirena®, Bayer Oy, Turku, Finland; available since 1980), copper intrauterine device (IUD - available since 1980) and DMPA users showed a trend of cumulative higher discontinuation rates due to menopause when compared with the discontinuation rates due to sterilization. Over the study period, a steep decline in the use of sterilization occurred. Conclusion Over the past 15 years of research we have observed a trend: women usually preferred to continue using LARC methods or DMPA until menopause rather than decide for sterilization, be it their own, or their partners’. The annual number of sterilizations dropped in the same period. The use of LARC methods and DMPA until menopause is an important option to avoid sterilization, which requires a surgical procedure with potential complications. © 2016 by Thieme Publicações Ltda, Rio de Janeiro, Brazil.385210217#573747/2008-3, FAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Geophagia in a large felid in captivity: A case report of lethal gastrointestinal impaction in a Bengal tigress (Panthera tigris tigris)

Deliberate geophagia or sand-eating behaviour has been widely documented in herbivorous and omnivorous mammals, but never in large felids at captivity. Here we report a case of apparent lethal gastrointestinal impaction from sand intake in a 10-year-old captive Bengal tigress. After 2 days of anorexia and prostration the tigress was admitted to the University Veterinary Hospital with abdominal distension and diarrhoea and died shortly afterwards. A post-mortem examination revealed oesophageal perforation, abundant liquid in the stomach and pyloric obstruction due to the presence of compacted sand and some masses of poultry bones. It is hypothesized that geophagy (of sand) may have been a strategy to alleviate indigestion by consumption of rotten poultry carcasses, but evolved into a compulsive/obsessive-compulsive disorder over time, possibly due to a restricted and barren environment. Zoo animal welfare involves a series of challenges that include an adequate diet in quantity and presentation, as well as complex behaviours such as the motivation to ingest non-food substances under certain contexts during life in captivity

Higher vertical jumping asymmetries and lower physical performance are indicators of increased injury incidence in youth team-sport athletes

To date, the literature looking at the association between injury-risk factors and actual injury incidence in young elite team-sports athletes is scarce. The main objective of the present study was to examine how modifiable factors may affect injury incidence. Eighty-one young elite team-sports athletes (age: u-14 to u-18) performed the countermovement jump (CMJ), a single leg CMJ (SLCMJ), the one-legged hop test (OLHT), a 30 m sprint test, the v-cut test, a repeated sprint ability and the 30-15 intermittent fitness test during the pre-season period. Inter-limb asymmetries were calculated for SLCMJ and OLHT. Injuries were recorded prospectively for the entirety of the 2017-2018 season. Comparison of injury and non-injury data was carried out using a two-way analysis of variance (ANOVA). Results of the ANOVA according to injury showed significant differences in CMJ (p = 0.01), SLCMJ on the lowest performing limb (p = 0.03) and SLCMJ asymmetry (< 0.001). Sex*injury interaction was significant from CMJ (p = 0.018) and 30-15 IFT (p = < 0.001). In conclusion, the current study indicated that athletes with greater inter-limb asymmetries, less vertical jump capacity and lower intermittent aerobic fitness had a greater predisposition to injury. Therefore, monitoring CMJ, aerobic performance and inter-limb asymmetries is recommended given their sensitivity to detect significant differences between injured and healthy youth athletes