459 research outputs found

    Counting all cubes in {0,1,...,n}^3

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    In this paper we describe a procedure of calculating the number cubes that have coordinates in the set {0,1,...,n}. We adapt the code that appeared in [11] developed to calculate the number of regular tetrahedra with coordinates in the set {0,1,...,n}. The idea is based on the theoretical results obtained in [13]. We extend then the sequence A098928 in the Online Encyclopedia of Integer Sequences to the first one hundred terms.Comment: 24 pages, 5 figure

    Effects of land use practices on livelihoods in the transboundary sub-catchments of the Lake Victoria Basin

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    The Lake Victoria Basin (LVB) is experiencing changes in land use due to both anthropogenic and natural drivers which are critical to the sustainability of the resources and livelihoods of the communities. Indeed the resultant land use practices and decisions made by the communities on the use of the land rely on the changes in the basin. This paper presents an analysis of the land use practices in the Lake Victoria Basin using two sub-catchments of Mara River (Tanzania) and Sio River (Kenya-Uganda) as case studies. Collection of mainly socio-economic and environmental data involved in-depth interviews of 679 respondents from the midstream and downstream zones of the subcatchments. The findings reveal conspicuous changes in community livelihoods as a result of expansion of cultivation, overgrazing on the river banks, increased use of wetlands areas, the disappearance and extreme fragmentation of forest, bush land and appearance and the diminishing of settlements. The hitherto common resources have become scarce forcing farmers to try intensifying and diversifying their farm production with little success due to poor traditional farming practices. Although local initiatives are leading to change, there is need for integrated approaches of indigenous knowledge, technical agricultural research, economic analysis, and policy studies and reforms.Key words: Land use practices, livelihoods, Indigenous knowledge, Lake Victoria basin

    Quality of two table grape guard cultivars treated with single or dual-phase release SO2 generators

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    Berries of seeded table grapes (cultivars Napoleón and Aledo) were trimmed in commercial packing houses, inoculated with Botrytis cinerea, packed with single and dual-phase release SO2 pads, and stored for up to four months at 0 ºC and 85±5 % relative humidity. Control grapes with or without inoculation, but without SO2 pads, were stored for up to 2 months. Botrytis cinerea rot (grey mould) limited the shelf-life of Aledo grapes to one month, while a two month shelf-life was established for Napoleón grapes, which suffered from berry splitting, Cladosporium herbarum and Botrytis cinerea rots. Yeasts of the Candida genera and secondary fungi were also identified in fruit suffering sour rot after 2 months at 0oC. No differences in grey mould development in the treatments without SO2 pads with or without inoculation. The native grey mould of these grapes was purified and included as the B. cinerea strain 20248 in the Spanish Type Culture Collection. Storage time, but not SO2 pads, slightly affected fruit quality. During the first month at 0oC, total soluble solids decreased by 1oBrix in 'Áledo' and berry hardness temporarily increased by around 30% in both cultivars. The pads provoked an SO2 taste acceptable for consumption, which was slightly higher in Napoleón than in Aledo grapes. The dual-phase release SO2 pads showed better performance for the long-term storage of grapes than single-release pads (both as regards berry sensory attributes and stem appearance, with lower stem browning). The dual-phase release SO2 pads extended the shelf-life of grapes by around 1 month, depending on the cultivar. Napoleón grapes showed a better potential for longterm storage than Aledo grapes due to thicker and more compact epidermis, thicker cell walls, and different epidermal microstructure including the transition cells between epidermis and the parenchyma

    La ontología materialista y cientista de Manuel Gonzáles Prada

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    Manuel Gonzalez Prada is an icon in the philosophical and cultural history of our country, so historically situating him is always a matter of controversy. In this case, I intend to demonstrate that MGP’s thought cannot be inscribed in the traditional positivist perspective, but in the materialist one. To this end, I review his production and highlight the aspects that would make him, indeed, a materialist renovation.Manuel González Prada es un ícono en la historia filosófica y cultural de nuestro país, por ello situarlo históricamente siempre es motivo de polémica. En este caso, me propongo demostrar que el pensamiento de MGP no puede inscribirse en la perspectiva tradicional del positivismo y sí del materialismo. Para lo cual hago un repaso de su producción y destaco los aspectos que lo harían, efectivamente, una renovación materialista

    Estimation of the aboveground biomass in the trans-boundary River Sio Sub-catchment in Uganda

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    The enormous land cover in Uganda is rapidly being depleted or encroached. To examine this, the study aimed at estimating the above-ground biomass in River Sio sub-catchment in Uganda. The study utilized an ortho-rectified Landsat TM/ETM image of 2004 which was classified using NDVI classification system for the aboveground biomass assessment in ILWIS 3.3 software. A total of 42 homogenous sampling sites were identified for biomass estimation along six laid transects measuring 500m long. The seven randomly selected sampling plots measured 50m X 50 m. The classification showed that Bushlands (0.17), wetlands (0.03) and small scale farming (- 0.29-0.03) had relatively more medium and low biomass ranges compared to grasslands (-0.41/-0.29) which mainly comprised of bare land. The above ground biomass was relatively higher in bushlands (4.9 tons) and wetlands (4.7 tons) compared to non-uniform small scale farming (farmlands) with 3.9 tons and grasslands with 1.6 tons. The variation in biomass shows that the sub-catchment requires an urgent need for land use/cover planning and management to prevent further degradation of land cover

    Fricke and polymer gel 2D dosimetry validation using Monte Carlo simulation

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    Complexity in modern radiotherapy treatments demands advanced dosimetry systems for quality control. These systems must have several characteristics, such as high spatial resolution, tissue equivalence, three-dimensional resolution, and dose-integrating capabilities. In this scenario, gel dosimetry has proved to be a very promising option for quality assurance. In this study, the feasibility of Fricke and polymer gel dosimeters suitably shaped in form of thin layers and optically analyzed by visible light transmission imaging has been investigated for quality assurance in external radiotherapy. Dosimeter irradiation was carried out with a 6-MV photon beam (CLINAC 600C). The analysis of the irradiated dosimeters was done using two-dimensional optical transmission images. These dosimeters were compared with a treatment plan system using Monte Carlo simulations as a reference by means of a gamma test with parameters of 1 mm and 2%. Results show very good agreement between the different dosimetric systems: in the worst-case scenario, 98% of the analyzed points meet the test quality requirements. Therefore, gel dosimetry may be considered as a potential tool for the validation of other dosimetric systems.Fil: Vedelago, José Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Chacón Obando, D.. Universidad Nacional. Physics Department; Costa Rica. Universidad Nacional de Córdoba; ArgentinaFil: Malano, Francisco Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Conejeros, R.. Servicio de Radioterapia, Icos. Temuco, Chile;Fil: Figueroa, R.. Universidad de la Frontera; ChileFil: Garcia, D.. Servicio de Imagenes por Resonancia Magnética; ChileFil: González, G.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Romero, Marcelo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Santibañez, M.. Servicio de Imagenes por Resonancia Magnética; ChileFil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Velásquez, J.. Servicio de Radioterapia; ChileFil: Mattea, Facundo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valente, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad de La Frontera. Departamento de Ciencias Físicas; Chil

    Understanding Common Perceptions of the Drylands

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    Drylands occupy over 40% of the earth’s surface and are home to more than 2 billion people. Drylands are key to the food and nutritional security of the planet and vital to the economies and livelihoods of dryland inhabitants. Yet, drylands are commonly perceived as unproductive, economically inefficient and marginal lands where small-scale farmers and pastoralists practice environmentally degrading activities. Driven by inadequate understanding and misconceptions of the drylands, policy-makers devise inappropriate policies and interventions. The BRECcIA project developed an online Drylands Perceptions Survey to understand the perceptions of researchers, practitioners and policy makers working in the drylands of Kenya, Malawi and Ghana. This paper presents results from a pilot of 40 responses and is part of a wider ongoing study. Results show that many respondents subscribe to a number of common drylands statements or assumptions, although other statements are challenged and respondents disagree with the assumptions. In another set of cases, respondents had mixed views and a more nuanced picture emerged that is context dependent. Through the BRECcIA project, the survey findings are being used to shape the development of new and revised dryland training courses with a more critical policy and research focus for policy-makers, practitioners, researchers and students in Kenya

    Exposure to community violence and Callous-Unemotional traits in young children: the role of positive parenting

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    IntroductionStudies regarding environmental contributions on callous-unemotional (CU) traits in children have informed about the protective role of positive parenting. However, it has not been explored whether findings from these studies -mostly conducted in High-Income Countries- can be generalised to Low-Middle-Income Countries (LMICs). Exposure to community violence is common in LMICs and is associated with emotional and behavioural problems in children. Therefore, it may represent an environmental risk factor for CU traits.ObjectivesThis prospective study explores whether positive parenting has a protective role in relation to CU traits in young Colombian children whose families have been exposed to community violence.MethodsWe assessed 235 families with children at age 3.5 years, from three contrasting regions of Colombia, using observations of mother-child interactions and maternal reports of community violence at ages 3.5 and 5.0 years.ResultsHierarchical multiple linear regression models indicated that maternal positivity at 3.5 years was associated with lower CU traits at age 5.0 years only in children of families exposed to community violence (interaction term p= .001). In the exposed group maternal positivity explained 10% of the variance (β= -.34, p= .001) with low positivity associated with elevated CU traits and high positivity with low CU traits. Maternal praise was not associated with CU traits. However, maternal negativity during play was associated with elevated CU traits as a main effect.ConclusionsBased on these findings, whether or not exposure to community violence is associated with elevated CU traits depends on maternal positivity, with low positivity creating vulnerability, and high positivity, resilience.DisclosureNo significant relationships.</jats:sec

    Algorithm To Architecture Mapping Model (ATAMM) multicomputer operating system functional specification

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    A functional description of the ATAMM Multicomputer Operating System is presented. ATAMM (Algorithm to Architecture Mapping Model) is a marked graph model which describes the implementation of large grained, decomposed algorithms on data flow architectures. AMOS, the ATAMM Multicomputer Operating System, is an operating system which implements the ATAMM rules. A first generation version of AMOS which was developed for the Advanced Development Module (ADM) is described. A second generation version of AMOS being developed for the Generic VHSIC Spaceborne Computer (GVSC) is also presented

    Geosynthetic reinforcement for reflective cracking reduction in asphalt pavements

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    A survey by the National Confederation of Transportation of Brazil (CNT, 2011) shows that 47.9% of the country’s roads need urgent interventions to recover satisfactory traffic conditions. This paper presents results of an investigation on the use of geosynthetic reinforcement in asphalt pavements with reference to capping of old courses. The use of geosynthetic reinforcement was intended to reduce crack reflection between an old surface course and the new hot mix asphalt (HMA) layer. In order to investigate crack reflection, two prismatic beams of dense HMA were prepared and geogrids or a geocomposite (geogrid with a geotextile coated with bitumen) reinforcement was placed in between them. An initial crack was induced by cutting the lower HMA specimen and a vertical cyclic loading was applied with a steel plate at the center of top layer. The test was interrupted when the vertical displacement at the surface reached 25 mm. The results show that geogrid reinforcement may increase by up to 15 times the number of loading cycles required to reach the pre-established value of vertical displacement (25 mm). In addition, it was noticed that the severity of the cracking mechanism was reduced and that crack reflection to the upper layer was reduced by the reinforcement inclusion
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