Police aviation support as fundamental citizen security through surveillance and air patrols

Este trabajo se desarrolló teniendo en cuenta la necesidad de integrar la aviación policial a las labores fundamentales de la Policía Nacional de acuerdo a su misión constitucional de garantizar la convivencia y seguridad ciudadana. Por tal motivo se diseña esta propuesta en busca de generar las alternativas necesarias que garanticen la evolución del servicio de policía y a la vez permitan colaborar con el cumplimiento de la misión institucional. En la actualidad la aviación policial enfoca sus esfuerzos básicamente en la lucha contra el narcotráfico, bandas criminales, destrucción de laboratorios para el procesamiento de narcóticos, por lo cual hay que prepararse para dar respuesta a las necesidades de la ciudadanía en el postconflicto donde se trasladan los problemas de seguridad a las ciudades.This work was developed taking into account the need to integrate the police aviation to the fundamental tasks of the National Police according to their constitutional mission of ensuring coexistence and security. Therefore this proposal is designed to generate the necessary search of alternatives to ensure the development of the police service and also allow work to fulfilling the institutional mission. Today aviation police basically focuses its efforts in the fight against drug trafficking, criminal gangs, destroying laboratories for narcotics processing, so we must prepare to respond to the needs of citizens in the post-conflict where move security problems in the cities

Contenido de metales y metaloides en presentaciones de atún comercializadas en Galicia. Estimaciones riesgo/beneficio para la salud del consumidor

La riqueza nutricional del atún, dada su condición de pez depredador, se cuestiona por el contenido en mercurio. En este trabajo, se determinaron los niveles de metales/metaloides (mercurio, cadmio, plomo, arsénico y selenio) en las presentaciones de atún más habituales comercializadas en Galicia. Los resultados mostraron una presencia, estadísticamente significativa, mayor de Hg, Cd y As en atún fresco. El mercurio destacó como principal contaminante, superando incluso muestras en fresco el límite máximo permitido por la Legislación de 1,0 mg kg-1. Comparando las conservas según su líquido de cobertura, la preparación en escabeche mostraba los niveles más bajos de Hg, Cd, As y Se; la acidez del medio puede contribuir a esta reducción. Partiendo de los datos de consumo nacionales y las concentraciones de estos elementos se estimó, mediante índices, el riesgo de padecer efectos adversos por toxicidad crónica. Así, se aplicaron los criterios THQ (Cociente de Riesgo Objetivo) y HI (Índice de Riesgo) propuestos por la Agencia de Protección Ambiental de Estados Unidos (US-EPA). El valor HI > 1 en edad infantil (3-6 años) alerta de riesgo por consumo de atún. Por último, se realizaron estimaciones riesgo/beneficio que integran al Se como antagonista del metilmercurio. Estos índices mostraron que los niveles de Se del atún eran suficientes para proteger al consumidor de su contenido en Hg, y, además, su consumo contribuye notablemente para alcanzar un estatus de Se adecuado. Finalmente, se presenta una propuesta de nuevo índice BRV (Valor Beneficio Riesgo) que considera el antagonismo del Se sobre el As y el Hg

High school mathematics teachers’ learning experiences, during a professional development intervention to improve their understanding of linear and quadratic functions using GeoGebra

Thesis (PhD)--Stellenbosch University, 2021.ENGLISH SUMMARY : Mathematics is a compulsory subject at all levels of pre-tertiary Namibian education and mathematical functions are key concepts of the mathematics curriculum. Personal experience has shown that teaching and understanding functions is a challenge in the Namibian high school curriculum. There are several difficulties in learning algebra due to misconceptions and errors such as misunderstanding the meaning of numerical and literal symbols, the shift from numerical data or language representation to variables or parameters with functional rules or patterns, and their cognition. Hence, there is a need to integrate the use of information and communication technologies (ICTs) in order to improve the understanding and teaching of mathematical functions. However, successful integration depends on providing teachers with learning opportunities in using ICTs. The focus of this research was to investigate a selected number of high school mathematics teachers‟ learning experiences during a professional development intervention aimed at improving the understanding of functions using GeoGebra. This study provides answers to the following questions: (1) What are high school mathematics teachers‟ learning experiences, during a professional development intervention to improve their understanding of linear and quadratic functions using GeoGebra? (2) What does research have to say about the potential of GeoGebra in aiding the understanding functions? The study was conducted in the Ohangwena region in Namibia and grounded on the interpretive paradigm. The sample population consisted of ten high school mathematics teachers. Sampling of the participants was guided by convenience sampling procedures. Five workshops of 2-3 hours were organised with the selected teachers. During these workshops, guidance and time were given to the teachers to explore different activities related to multiple representations of mathematical functions. The teachers were interviewed while they interacted with a set of GeoGebra activities. A group discussion was held to explore and develop an understanding of the concept of functions, the nature of GeoGebra and its possible pedagogical affordances. Multiple methods were used to collect data, namely semi-structured interviews; focus group interviews; audiotaped discussions; observations; and field notes. Based on a qualitative analysis of the data generated, the findings indicated that teachers benefited significantly from the use of GeoGebra as mathematical digital software in various ways, ranging from personal mathematics exploration, attitudes toward mathematics and mathematics teaching of functions to pedagogical reflections, including the nature of mathematics and teachers interactions. These changes are well aligned with the emphases of the ongoing mathematics education reforms in Namibia, including the integration of technology into education. The research findings also revealed that in its design GeoGebra affords fast and consistent feedback and that teachers need more opportunities where they learn to experience relations between the pragmatic and epistemic dimensions of GeoGebra use, when it comes to linear and quadratic functions, for example.AFRIKAANSE OPSOMMING : Wiskunde is „n verpligte vak in al die fases van voortersiêre onderwys in Namibië en wiskundige funksies is van die kernkonsepte in die wiskundekurrikulum. Persoonlike ervaring wys daarop dat die onderrig en verstaan van funksies „n uitdaging in die Namibiese hoërskoolkurrikulum blyk te wees. Daar is verskeie struikelblokke in die leer van algebra. Dit kan te wyte wees aan wanopvattings en foute soos die misverstaan van numeriese en lettersimbole, die skuif van numeriese data of taalverteenwoordiging na veranderlikes of grense met funksionele reëls of patrone en die herkenning daarvan. Vandaar die behoefte om die gebruik van inligting- en kommunikasietegnologieë (IKTs) te integreer ten einde die verstaan en die onderrig van wiskundige funksies te verbeter. Die sukses van hierdie insluiting hang egter af van die mate waartoe ondewysers toegang tot leergeleenthede in die gebruik van IKTs gegun word. Met hierdie navorsing is daar gefokus op die ondersoek na „n gekose aantal hoërskool-wiskundeonderwysers se leerervarings tydens „n professionele ontwikkelingsintervensie, wat daarop gemik was om die verstaan van wiskundige funksies te bevorder deur die gebruik van GeoGebra. Met hierdie studie is daar gepoog om antwoorde op die volgende vrae te vind: (1) Wat is hoërskool-wiskundeonderwysers se leerervarings gedurende die bywoning van „n professionele ontwikkelingsintervensie wat daarop gemik is om die verstaan van wiskundige funksies te bevorder deur die gebruik van GeoGebra? (2) Wat is die bevindings van navorsing oor die moontlikhede van GeoGebra in die ontwikkeling van „n beter begrip van funksies? Die ondersoek is onderneem in die Ohangwena-distrik in Namibië en dit is gegrond op die interpretatiewe paradigma. Die deelnemers vir die steekproef bestaan uit tien hoërskool-wiskundeonderwysers. Die keuse van deelnemers is gelei deur doelbewuste steekproefprosedures. Vyf werkswinkels van 2 tot 3 ure elk is vir die gekose onderwysers gereël. Gedurende hierdie werkswinkels is die onderwysers begelei en daar is tyd gegee om verskillende aktiwiteite met betrekking tot die veelvuldige voorstellings van wiskundige funksies te ondersoek. Onderhoude is met die onderwysers gevoer, terwyl hulle besig was met „n stel GeoGebra-aktiwiteite. „n Groepsbespreking het plaasgevind oor die begrip wiskundige funksies om die verstaan daarvan te ontwikkel. Die aard van GeoGebra is ook bespreek en die moontlikhede daarvan as „n pedagogiese hulpmiddel is ondersoek. „n Verskeidenheid metodes is aangewend om data in te win, soos die voer van deelsgestruktureerde onderhoude, fokusgroeponderhoude, die maak van oudio-opnames van gesprekke, deur waarneming en met die byhou van veldnotas. Gebaseer op die kwalitatiewe ontleding van die gegenereerde data is daar bevind dat onderwysers beduidend kan baat vind by die gebruik van GeoGebra as „n wiskundige, digitale grensobjek (WDGO). Dit kan op verskeie wyses aangewend word, soos byvoorbeeld tydens persoonlike ondersoeke na wiskunde, in die aanspreek van die houding jeens wiskunde, by die onderrig van wiskundige funksies of tydens pedagogiese refleksies oor die aard van wiskunde, asook tydens onderwyserinteraksies. Hierdie veranderinge klop met die volgehoue hervorming van wiskundeonderwys in Namibië wat ook die integrasie van tegnologie in opvoeding insluit. Die navorsingsbevindige bring voorts aan die lig dat GeoGebra, as „n WDGO, vinnige en deurlopende terugvoer toelaat en dat onderwysers meer geleenthede behoort te kry waartydens hulle die verhouding tussen die pragmatiese en die epistemiese dimensies van GeoGebra-gebruik kan ervaar, veral wanneer dit kom by liniêre en drievoudige funksies.Doctora

Estudio del pleuston y bafon de las lagunas de Chascomus y Yalca

Se estudia la mesofauna asociada a la vegetación flotante y sumergida en las lagunas del epígrafe, realizándose un análisis cuali y cuantitativo de la misma y del sustrato, así como también su variación estacional. Se describe el método utilizado en la obtención de las muestras y extracción de la mesofauna, así como también se pone de manifiesto el criterio seguido para la selección de las “asociaciones vegetales” que sirven de sustrato a la fauna en cuestión. Tres asociaciones flotantes fueron seleccionadas y se individualizaron con el nombre de la especie dominante: Ricciocarpus natans; Azolla filiculoides y Salvinia rotundi- folia; siendo dos las sumergidas: Ceratophyllum demersum y Potamogetón striatus. Se describe cada asociación respecto de su extensión, permanencia y fluctuaciones a lo largo de un año calendario, así como también se da a conocer la lista de presencias de las distintas taxias discriminadas por asociación. Se analizan los pleustontes y bafontes de cada asociación, y sus posibles relaciones interespecíficas y con el sustrato, demostrándose la existencia de especies caracterizantes en cada uno de los mismos, siendo algunas exclusivas; se analizan, además, mediante correlaciones, las relaciones predator-presa y animal sustrato en cada asociación. La aplicación del índice de diversidad específica pone de manifiesto la madurez de las distintas asociaciones flotantes consideradas y la mayor o menor influencia del sustrato como elemento morigerador de los agentes externos en relación con el ciclo anual de los componentes de su mesofauna, evidenciándose en dos de ellos un comportamiento estacional similar al del plancton. De las consideraciones de estas poblaciones y sus relaciones con el ambiente acuático se propone dividir al pleuoton en: eupleuston y hemipleuston y un extrapleuston: pseudopleuston.In the Chascomús and Yalca lagoons, the mesofauna associated with floating and submerged vegetation was studied through a cualitative- quantitative analysis which also included the substratum and the seasonal variations. After a description of the sampling technique employed and the method of extraction of mesofauna, there follow-s an explanation of the criterium adopted in selecting the “vegetable associations’’ which act as a subtratum for the analysed fauna. Three floating associations each named after the dominant species, were selected: Ricciocarpus natans, Azolla filiculoides and Salvinia rotundifolia; two submerged associations were also studied: Ceratophillum demersum and Potamogetón stria- tus. Each association is described in relation to extensión, permanency and fluctuation through a whole calender year, and a list of presences of different taxias discriminated by association is presented. In each association an analysis of the “pleustontes” and ‘ bafontes” and of their interespecific relations as well as those related to the substratum, which have shown the existence of species characteristic of each substratum, some of them exclusive. Furthermore, through correlations, each association was determined the relationships predator-prey and animal-substratum. The application of the “Índex of specific diversity” has shown the maturity of the different floating associations and the greater or lesser influence of the substratum as a moderating element of external agents related to annual cycle of the constituents in the meso- fauna. In two of them a seasonal behavior, similar to that of plankton, has been evinced. From a consideration of these populations and their relation-ships to the acqueos environmets, it is proposed to divide pleuston into: eupleuston, hemipleuston and a extrapleuston: pseudopleuston

Survivability analysis of tape-tether against multiple impact with tiny debris

We show that for a tether at 800 km altitude, which is 5 km long, 2 cm wide and 0.05 mm thick, the risk of substantial damage during a 3 month period due to multiple impacts with debris or micrometeoroids is low, of about 1.4%. By substantial damage we mean that if the tape is divided in 2 cm2 cm squares, then in some square the damaged area by bombardment with debris or micrometeoroids exceeds 11% of the area of the square. Furthermore, we show that the danger posed by the micrometeoroids is negligible compared to the risk posed by the debris

A comparative analysis of costs of single and dual rapid HIV and syphilis diagnostics: results from a randomised controlled trial in Colombia.

BACKGROUND: HIV and congenital syphilis are major public health burdens contributing to substantial perinatal morbidity and mortality globally. Although studies have reported on the costs and cost-effectiveness of rapid diagnostic tests (RDTs) for syphilis screening within antenatal care in a number of resource-constrained settings, empirical evidence on country-specific cost and estimates of single RDTs compared with dual RDTs for HIV and syphilis are limited. METHODS: A cluster randomised controlled study design was used to compare the incremental costs of two testing algorithms: (1) single RDTs for HIV and syphilis and (2) dual RDTs for HIV and syphilis, in 12 health facilities in Bogota and Cali, Colombia. The costs of single HIV and syphilis RDTs and dual HIV and syphilis RDTs were collected from each of the health facilities. The economic costs per woman tested for HIV and syphilis and costs per woman treated for syphilis defined as the total costs required to test and treat one woman for syphilis were estimated. RESULTS: A total of 2214 women were tested in the study facilities. Cost per pregnant woman tested and cost per woman treated for syphilis were US$10.26 and US$607.99, respectively in the single RDT arm. For the dual RDTs, the cost per pregnant woman tested for HIV and syphilis and cost per woman treated for syphilis were US$15.89 and US$1859.26, respectively. Overall costs per woman tested for HIV and syphilis and cost per woman treated for syphilis were lower in Cali compared with Bogota across both intervention arms. Staff costs accounted for the largest proportion of costs while treatment costs comprised <1% of the preventive programme. CONCLUSIONS: Findings show lower average costs for single RDTs compared with dual RDTs with costs sensitive to personnel costs and the scale of output at the health facilities. TRIAL REGISTRATION NUMBER: NCT02454816; results

Consideraciones sobre la enseñanza de la matemática en el ciclo diversificado colombiano

El documento comienza con un breve análisis del ciclo diversificado en Colombia. Los autores proponen y discuten algunos temas matemáticos sobre lógica y teoría de conjuntos, computación, cálculo, probabilidad y estadísticas que deberían tratarse en dicho nivel educativo

Self-complementary metasurface for designing narrow band pass/stop filters

A self-complementary metasurface is studied in this paper. The metasurface is a 2-D periodical arrangement of unit cells formed by a metallic printed split ring resonator and its complementary counterpart. It is demonstrated that this structure behaves like a very selective band-pass filter for a certain linear polarization while band-stop filtering is achieved for the orthogonal polarization over the same frequency range. This idea opens the door to a new class of frequency selective surfaces made of connected and unconnected elements, whose filtering properties are mechanically tunable from band-pass to band-stop by rotating the surface or the polarization.Colombian Administrative Departament of Science, Technology and Innovation 1101-521-29389Ministerio de Ciencia e Innovación CSD2008-00066, TEC2010-1694

The long journey of Orthotrichum shevockii (Orthotrichaceae, Bryopsida): From California to Macaronesia

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Biogeography, systematics and taxonomy are complementary scientific disciplines. To understand a species' origin, migration routes, distribution and evolutionary history, it is first necessary to establish its taxonomic boundaries. Here, we use an integrative approach that takes advantage of complementary disciplines to resolve an intriguing scientific question. Populations of an unknown moss found in the Canary Islands (Tenerife Island) resembled two different Californian endemic species: Orthotrichum shevockii and O. kellmanii. To determine whether this moss belongs to either of these species and, if so, to explain its presence on this distant oceanic island, we combined the evaluation of morphological qualitative characters, statistical morphometric analyses of quantitative traits, and molecular phylogenetic inferences. Our results suggest that the two Californian mosses are conspecific, and that the Canarian populations belong to this putative species, with only one taxon thus involved. Orthotrichum shevockii (the priority name) is therefore recognized as a morphologically variable species that exhibits a transcontinental disjunction between western North America and the Canary Islands. Within its distribution range, the area of occupancy is limited, a notable feature among bryophytes at the intraspecific level. To explain this disjunction, divergence time and ancestral area estimation analyses are carried out and further support the hypothesis of a long-distance dispersal event from California to Tenerife IslandThis research was funded by the Spanish Ministry of Education and Science (CGL2007- 61389/BOS) to F.L., the Spanish Ministry of Science and Innovation (CGL2011-28857/BOS) to V.M., the Spanish Ministry of Economy and Competitiveness (CGL2013-43246-P) to R.G., and the Spanish Ministry of Economy, Industry and Competitiveness (CGL2016-80772-P) to I.D. and the Spanish Ministry of Economy and Competitiveness (grants IJCI-2014-19691 and RYC-2016-20506) to J.P. J.P. also received the H2020 Marie Skłodowska-Curie Actions grant 747238. J.M.G-M and A.L-L. are grateful for funding from Parque Nacional del Teide. B.V. benefited from the support of the Ministry of Economy and Competitiveness through grant BES2012-051976 of the Formación de Personal Investigador (FPI) programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Characterization of the skin and gill microbiomes of the farmed seabass (Dicentrarchus labrax) and seabream (Sparus aurata)

There is substantial evidence showing that the microbiome of teleosts plays a key role in host health and wellbeing. Aquaculture practices increase the risk of dysbiosis (i.e. microbial imbalance), which is known to facilitate pathogen infections. The skin and gills are the primary defense organs against pathogens, thus, characterizing their microbiome composition in farmed fish is pivotal for detecting potential alterations that may lead to disease susceptibility. Here, we assessed the skin and gill microbiomes of two of the most important adult fish species farmed in southern Europe, the seabass and the seabream, during winter months. We coupled next-generation sequencing (MiSeq) of the 16S rRNA V4 region with the DADA2 bioinformatic pipeline to assess microbial composition and structure. Variation in microbial alpha-diversity (intra-sample) and taxa proportions were assessed using analysis of variance. Differences in beta-diversity (between-sample) were tested using permutational multivariate analysis of variance. Microbiomes of both tissues (n = 30 per species) identified 19 bacteria phyla, dominated by the phyla Proteobacteria (44–68%) and Bacteroidetes (15–37%); the families Flavobacteriaceae (11–28%), Rhodobacteraeae (4–8%) and Vibrionaceae (2–17%); and the genera Rubritalea (4–13%), Pseudomonas (4–8%) and the NS3a marine group (4–12%). Mean relative proportion of these taxa, some alpha-diversity indices and all beta-diversity distances varied significantly between tissues within and between species. ASVs belonging to the genera Polaribacter and Vibrio, which include several species that are pathogenic, were detected in the core microbiomes of seabass or seabream