1,565 research outputs found

    Atelier da rua: A participated street design process

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    Streets are key elements on the city urban structure. Despite the importance of this structural and living urban element, the contemporary Portuguese situation is characterized by the lack of investment in the realization, use and maintenance of many streets. Moreover it is noted the local authorities difficulties to deal with citizens everyday life problems within the street and to approach diffuse and weakened civic structures. These are some of the problems encountered in small and local scale architectural projects of the public space of the streets in Portugal. Participated project processes tackle these issues through the understanding of the existing problems and promoting new processes to face them. This paper is done in the scope of the research of Atelier da Rua (Street Atelier) that is developed to meet contemporary needs of intervention in the street public space. The methodological hypothesis is to use the strategy of Atelier da Rua, a citizen participative process applied to propose effective design projects in order to improve community living and physical spaces. This paper aims to explore the combination of street intervention methodology of Atelier da Rua (Pita, 2014 b) and the values presented in the text A ladder of citizen participation written by Sherry Arnstein (1969), focusing in the particular issue of achieving “partnership” on the Atelier da Rua investigation and practice.info:eu-repo/semantics/publishedVersio

    Novel designs for Penning ion traps

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    We present a number of alternative designs for Penning ion traps suitable for quantum information processing (QIP) applications with atomic ions. The first trap design is a simple array of long straight wires which allows easy optical access. A prototype of this trap has been built to trap Ca+ and a simple electronic detection scheme has been employed to demonstrate the operation of the trap. Another trap design consists of a conducting plate with a hole in it situated above a continuous conducting plane. The final trap design is based on an array of pad electrodes. Although this trap design lacks the open geometry of the traps described above, the pad design may prove useful in a hybrid scheme in which information processing and qubit storage take place in different types of trap. The behaviour of the pad traps is simulated numerically and techniques for moving ions rapidly between traps are discussed. Future experiments with these various designs are discussed. All of the designs lend themselves to the construction of multiple trap arrays, as required for scalable ion trap QIP.Comment: 11 pages, 10 figure

    First report and preliminary evaluation of cassava root necrosis in Angola

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    Open Access ArticleCassava is a main staple food for 800 million people world-wide. Production is limited by pest and pathogens. The most devastating cassava viruses are Cassava Brown Streak Virus and Uganda Cassava Brown Streak Virusboth causing severe root necrosis called Cassava Brown Streak Disease. In the last 10 years, the Cassava Brown Streak Disease (CBSD)has spread across Africa from the east coast of Africa to central Africa. Similar root necrosis to cassava brown streak disease has also been identified in the Democratic Republic of Congo where the first symptoms were identified in 2002 in Kinshasa and Kongo central province. In 2012, the presence of CBSD was confirmed in eastern Democratic Republic of Congo. All attempts since 2002 in western Democratic Republic of Congo to identify the cause of these root necrosis have failed. In 2017, a team of scientists surveying the Songololo Territory in the Kongo central province at the northern Angola, identified the same root necrosis similar to CBSD in several localities bordering Angola. These unexpected results will foreshadow the presence of cassava root necrosis in Angola. This preliminary investigation in northern Angola was conducted specifically in the Zaire province and the territory of Mbanza Kongo at approximatively 62 kms from the Democratic Republic of Congo border in order to verify, whether or not, these root necrosis are present in Angola. Results obtained from this exploratory survey in several fields of the Zaire province and territory of Mbanza Kongo confirmed, for the first time, the presence of cassava root necrosis in Angola, similar to CBSD, as identified in western DRC

    Reservas de Caza en España: la gestión pública de la caza

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    In Spain, Game Reserves (GR) are territorial public hunting management units that cover 3.5% of the country and ~ 10% of the Natura 2000 Network. The first GR were established in 1966 and by 2011 there were 49. Their primary purposes were to promote wild ungulate populations, their sustainable use, and to provide social, economic, and recreational benefits to local communities and hunters, generally. During the 1980s following a political federalization process, GR became the responsibility of regional governments and their role has never been evaluated, even though the political, rural ecological, and administrative frameworks underwent substantial changes. In this paper, we present a review of the state of GR in 2011, identify their successes and problems, and provide recommendations for the future. The GR have been fundamental to sustainable hunting and the protection of wildlife, particularly, game species. Currently, their virtues are not widely appreciated and they do not receive sufficient financial and human resources to meet their objective fully. We propose several initiatives that might improve the use of existing resources and increase the profile of these publicly managed areas.Las Reservas de Caza (RC) constituyen una figura de gestión cinegética pública del territorio en España. Abarcan el 3.5% del territorio y ocupan aproximadamente el 10% de la Red Natura 2000. Su declaración comenzó en 1966, y desde entonces no ha cesado, llegando en la actualidad a las 49 RC. Fueron creadas esencialmente para la promoción de las poblaciones de ungulados silvestres, el aprovechamiento ordenado de este recurso y la satisfacción social, económica y recreativa de las comunidades locales y de los cazadores en general. Quedaron fuera de la tutela del estado tras su descentralización a partir de principios de los años ochenta del pasado siglo, y su función en conjunto no ha sido nunca evaluada, al tiempo que el panorama político, rural, ecológico y administrativo ha sufrido profundos cambios. Este artículo pretende ofrecer una panorámica actualizada de la situación de las RC a principios del siglo XXI, evaluar sus logros y problemática actual, así como proponer algunas actuaciones para el futuro inmediato. Las RC han sido pioneras en el aprovechamiento sostenible de la caza y de gran utilidad para la protección de la fauna en general y las especies cinegéticas en concreto. Actualmente no gozan del reconocimiento popular, y no reciben los recursos necesarios económicos y humanos suficientes para seguir cumpliendo su función adecuadamente. Se proponen una serie de medidas para aprovechar mejor los recursos disponibles y poder dar a conocer a la sociedad el valor de estos terrenos de gestión pública

    Acquired Cytomegalovirus Infection in an Extremely Low-Birth Weight Infant Presenting with a Severe Sepsis-Like Syndrome

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    Cytomegalovirus infection is one of the most common congenital infections worldwide. Moreover, it seems to be an important cause of postnatally acquired infection. Perinatal transmission can occur intrapartum (from the birth canal), from a blood transfusion, via maternal breast milk, or from close contact with infected people. The risk of breast milk-acquired cytomegalovirus infection is higher in countries with a high prevalence of cytomegalovirus immunoglobulin G-positive women. Usually, acquired cytomegalovirus infection is asymptomatic, especially in term infants. However, preterm infants can present with a sepsis-like syndrome and multiple organ involvement. A high index of suspicion is required to make an early diagnosis. Therapeutic guidelines for symptomatic postnatal cytomegalovirus infection are not yet available. More studies are required to understand the long-term sequelae of postnatally acquired cytomegalovirus infection and know which is the best strategy to avoid cytomegalovirus post-natal transmission.info:eu-repo/semantics/publishedVersio

    An adaptive solver for viscoelastic incompressible two-phase problems applied to the study of the splashing of slightly viscoelastic droplets

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    We propose an adaptive numerical solver for the study of viscoelastic 2D two-phase flows using the volume-of-fluid method. The scheme uses the robust log conformation tensor technique of Fattal & Kupferman (2004,2005} combined with the time-split scheme proposed by Hao & Pan (2007}. The use of this time-split scheme has been proven to increase the stability of the numerical computation of two-phase flows. We show that the adaptive computational technique can be used to simulate viscoelastic flows efficiently. The solver is coded using the open-source libraries provided by the \basilisk \cite{Basilisk} platform. In particular, the method is implemented for Oldroyd-B type viscoelastic fluids and related models (FENE-P and FENE-CR). The numerical scheme is then used to study the splashing of weakly viscoelastic drops. The solvers and tests of this work are freely available on the Basilisk web sit

    It's Harder to Splash on Soft Solids

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    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. By imaging ethanol drops impacting silicone gels of different stiffnesses we show that substrate stiffness also affects the splashing threshold. Splashing is reduced or even eliminated: droplets on the softest substrates need over 70\% more kinetic energy to splash than they do on rigid substrates. We show that this is due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Young's moduli 100\lesssim 100kPa reduce splashing, in agreement with simple scaling arguments. Thus materials like soft gels and elastomers can be used as simple coatings for effective splash prevention. Soft substrates also serve as a useful system for testing splash-formation theories and sheet-ejection mechanisms, as they allow the characteristics of ejection sheets to be controlled independently of the bulk impact dynamics of droplets.Comment: 5 pages, 4 figure

    Attempts to identify Cassava Brown Streak Virus in western Democratic Republic of Congo

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    Open Access ArticleRoot necrosis similar to those of the cassava brown streak disease (CBSD) were observed on cassava in western provinces of the Democratic Republic of Congo (DR.Congo) in the early 2000’s. However molecular laboratory diagnosis were not able to detect any causative agent responsible for the attacks, hence, the disease related to these symptoms was named CBSD-like disease. In order to assess the distribution and the incidence of the CBSD-like disease, surveys were carried out in four western provinces, comprising, Kwango and Kwilu, Sud Ubangi, Kinshasa and Kongo Central. CBSD-like disease was observed in all surveyed provinces on the basis of root symptoms because foliar symptoms were different to those of the documented cases of CBSD in other parts of east Africa. CBSD-like disease incidence was high in Kongo Central and Sud Ubangi, exceeding an average of 50 %, but low in Kwango and Kwilu (32.8%) and in Kinshasa (19.1%). During the surveys, cassava leaf samples were collected for lab identification of the causal agent. PCR diagnosis was done on these samples using primers specific for the two known CBSVs. All samples tested negative with no amplification of DNA fragments of the correct size. Thus, further analysis on the causative organism is needed using Next Generation Sequencing (NGS) approaches. NGS approaches will help also to identify the causative organism in other Central Africa countries (Angola, Congo-Brazzaville and Gabon) where such cassava root necrosis have been reported or are suspected

    Assessing the severity and the incidence of Cassava Root Necrosis Disease (CRND) in western Democratic Republic of Congo

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    Open Access ArticleCassava is the staple food in the Democratic Republic of Congo (DRC) where both the roots and leaves are consumed. This crop is susceptible to several viral diseases, including Cassava Mosaic Disease(CMD) and Cassava Brown Streak Disease(CBSD) in eastern DRC. Following earlier studies that show root necrosis occurring in western DR Care not due to CBSD but to Cassava Root Necrosis Disease (CRND), an exploratory survey was conducted in western DRC from 2016 to 2017 in order to determine the distribution, the severity and the incidence of this disease (previously known as CBSD-like disease). NGS ( Next Generation Sequencing) results confirmed all the previous negative results obtained using PCR and CBSV primers. This suggests that microorganisms such as bacteria or fungi could be responsible for cassava root necrosis in western DRC and is not CBSD as predicted. Five provinces (Bas-Congo, Kinshasa, Bandundu, Equateur and Kasai-Oriental) were surveyed and data were collected according to the harmonized protocols adopted by countries within the West African Virus Epidemiology (WAVE) project. Statistical tests (ANOVA) performed on our data showed that CRND severity did not vary significantly among the provinces of Kinshasa, Bandundu and Bas-Congo which are the areas most affected by the disease. Bas-Congo and Kinshasa provinces presented the highest maximum disease severity (score 3 and 5 respectively), while Equateur province had the lowest disease severity score. Equateur province also had the highest percentage of healthy plants and few plants presented mild symptoms. The overall average of cassava root necrosis severity in western DRC ranged around 1.88 ± 0.08, an approximate score of 2. The overall mean incidence of CRND in western DRC was 22.24 ± 2.4% but reached 100% in localities considered as hotspots (Lukuakua in Bas-Congo and Nguma in Plateau des Batékés). The behaviour of cassava varieties against CRND is similar with CBSD in East Africa, most of improved varieties and landraces are susceptible to both diseases. Correlation analyses showed a positive correlation (r = 0.6940) between severity and incidence of CRND. Therefore, Bas-Congo province is the most affected province, while the province of Equateur is the least affected province in western DRC. Further investigations, including genomic surveillance, should also be conducted in the eastern DRC where CBSD is confirmed to know if CRND is found in conjunction with CBSD and to report possible instances of mixed infections. For medium-term disease control, our study suggests that the development and deployment of control measures including cultivars with resistance to CRND and CBSD should be a priority

    Cambios ontogenéticos e intraespecíficos observados en la rádula de Polycera aurantiomarginata García and Bobo, 1984 (Gastropoda Opisthobranchia)

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    Polycera aurantiomarginata García and Bobo 1984 has a stable population in the intertidal area of El Portil beach (Huelva, SW Spain). This fact allowed specimens of different sizes to be collected from March 2001 to December 2003. In this paper, the ontogenetic variations of the radula of P. aurantiomarginata are studied. The radulae of 141 specimens were examined, 138 from El Portil and 3 from La Herradura (Granada, SE Spain). Specimens of 1.5-2 mm in length lack the typical radula described for P. aurantiomarginata. They have the so called pre-radula whose teeth are different in size and shape from the typical radula of the adults. In the specimens of 3 and 4 mm the pre-radula coexists with the characteristic radula, which is the single structure present in the specimens larger than 4 mm. The following features of the radula are included in this study: radular length, number of teeth rows and length of the outer lateral teeth. According to the three measured variables, the affinities among specimens without a pre-radula were established through cluster analysis, which defined three different groups (4-10 mm, 11-22 mm and 23-48 mm). Correlations between specimen length and radula length, number of rows and mean length of outer lateral teeth were significant. Feeding strategies could be related to the different morphology of the radula established by the Cluster analysis.Polycera aurantiomarginata García y Bobo, 1984 muestra una población estable y en la localidad de El Portil (Huelva, SW de España), lo que ha permitido la recolección, desde marzo de 2001 hasta diciembre de 2003, de un alto número de ejemplares de todos los tamaños. En el presente estudio se ha extraído la rádula de 141 animales, 138 recogidos en la zona intermareal de El Portil y 3 en La Herradura (Granada). Los tamaños de los animales han oscilado entre 1.5 mm y 48 mm. Se ha podido observar en los individuos de entre 1.5 y 2 mm la existencia de una pre-rádula cuyos dientes son morfológicamente diferentes a los de la rádula de los individuos mayores; sin embargo, en los ejemplares de 3 y 4 mm esta pre-rádula coexiste con la rádula típica, siendo esta estructura la única presente en individuos de longitud igual o mayor a 4 mm. A cada una de las rádulas extraídas, tanto con pre-rádula o sin ella, se le ha medido la longitud total de la cinta, la longitud del diente lateral externo y el número de filas de dientes. Considerando los tres parámetros medidos, las afinidades entre los ejemplares sin pre-rádula se establecieron a partir de análisis de Cluster, que definieron tres grupos distintos (4-10 mm, 11-22 mm y 23-48 mm). Las correlaciones existentes entre la longitud de los individuos y la longitud de la rádula, el número de filas y la longitud media de los dientes fueron significativas. Las diferencias morfológicas reconocidas en los grupos considerados podrían estar relacionadas con distintas estrategias alimentarias.
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