4,303 research outputs found
On the Desirability of Coordinated Supply-side Intervention: Does a Monetary Union Matter?
No full textThis paper examines the desirability of coordinated supply-side intervention within a monetary union, given the constraints on monetary and fiscal policy. The author considers an economic framework featuring independent monetary policy. In general, coordinated intervention is most useful against shocks that require distinct policy responses in each separate economy.monetary union, supply-side policies, policy coordination
Controle de temperatura de secadores de revestimentos cerâmicos alimentados com gás natural
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.Esta dissertação, que tem um caráter teórico-prático, apresenta um estudo do processo de secagem de peças cerâmicas e analisa o projeto e ajuste do sistema de controle de temperatura de um secador vertical de ciclo contínuo. O estudo do comportamento do processo é realizado a partir de um modelo matemático obtido com dados experimentais do secador instalado na linha de produção de monoporosa da Eliane Revestimentos Cerâmicos - Unidade V, em Criciúma - SC. A partir do modelo obtido projetam-se diversas estratégias de controle clássico, controle PI, PID e uma técnica de controle preditivo, o Controle Preditivo Generalizado (GPC) baseado no preditor de Smith. A aplicação destas técnicas ao modelo simulado do secador, permite compara-las tanto do ponto de vista do comportamento dinâmico como da complexidade de implementação. As conclusões desta análise servem para indicar as modificações a serem implantadas no sistema de controle analógico existente no processo real. Finalmente, apresentam-se resultados experimentais com a utilização do controlador PI analógico instalado no processo que mostram as melhorias introduzidas no desempenho do sistema com o ajuste proposto para o controlador. Desta forma o trabalho contribui para a melhoria imediata do comportamento do secador e aponta para futuras modificações do sistema de medição e controle que permitiriam otimizar o seu desempenho
Beta2-microglobulina en líquido cefalorraquídeo de recién nacidos con infección congénita sintomática por citomegalovirus: Un indicador certero de la gravedad de la afectación del sistema nervioso central
No full textIntroducción. En los neonatos con infección congénita sintomática por citomegalovirus (CMV) la neuroimagen es la mejor herramienta disponible para predecir la evolución neurológica a largo plazo. Los hallazgos en líquido cefalorraquídeo (LCR) de estos pacientes han sido escasamente estudiados. La Beta2-microglobulina (β2-m) se encuentra elevada en el LCR de los recién nacidos con infecciones del sistema nervioso central (SNC).
Objetivos. (1) Determinar si la concentración de β2-m en LCR está aumentada en los neonatos con infección congénita sintomática por CMV, (2) examinar su correlación con los hallazgos de neuroimagen y (3) evaluar su valor para predecir el neurodesarrollo.
Métodos. Se incluyeron todos los pacientes con infección congénita sintomática por CMV nacidos entre 1993-2009 en el Hospital Universitario La Paz, Madrid. La población control estuvo formada por un grupo de neonatos en los que se determinó la β2-m en LCR como parte de los estudios por sospecha de sepsis, meningitis o encefalitis y que finalmente presentaron cultivos estériles y estado neurológico normal al alta. La β2-m se midió mediante inmunonefelomatría. Los hallazgos de neuroimagen (ecografía, TC y/o RM) se graduaron según una escala semicuantitativa validada (grados 0-3). Todos los pacientes fueron contactados para una evaluación sistemática de su neurodesarrollo a largo plazo, que incluyó: examen neurológico y, si parálisis cerebral, graduación según el GMFCS, evaluación cognitiva mediante las escalas BSID-III, WPPSI-III o WISC-IV, según la edad, y evaluación conductual mediante el ASEBA. Se registraron la presencia de epilepsia, déficit auditivo o visual. Para los pacientes no visitados a largo plazo, se revisaron las historias de Neurología o, si no recibían seguimiento, se realizó una entrevista dirigida a los padres. Las secuelas neurológicas se clasificaron según una graduación semicuantitativa (grados 1-3).
Resultados. Fueron incluidos 26 pacientes con infección congénita sintomática por CMV, 20 de ellos con determinación de β2-m en LCR y todos con neuroimagen neonatal. Tres casos fallecieron, 20 de los supervivientes fueron evaluados según el protocolo de seguimiento y en los otros tres la evaluación se hizo mediante los subrogados. La β2-m se encontró elevada con respecto a los 93 neonatos de la población control (mediana 7,2 mg/L versus 1,6 mg/L, P<0,001). Los neonatos con alteraciones graves en la neuroimagen (grados 2-3) presentaron cifras más elevadas de β2-m en LCR que aquellos con grados 0-1 (P=0,007). Asimismo, el biomarcador se encontró en concentraciones más elevadas entre los niños que ulteriormente presentaron secuelas moderadas o graves, o bien fallecieron (P=0,005). El análisis ROC mostró una aérea bajo la curva (ABC) de 0,84 ± 0,08, y valores de β2-m superiores a 7,9 mg/L predijeron evolución adversa: sensibilidad 69%, especificidad 100%, VPP 100%, VPN 63%. La presencia de alteraciones en la neuroimagen neonatal grados 2-3 predijo el desarrollo de secuelas moderadas, graves o la muerte (P=0,007): ABC 0,80 ± 0,08, sensibilidad 61%, especificidad 100%, VPP 100%, VPN 53%. La combinación de β2-m elevada o neuroimagen grados 2-3 mostró la mayor capacidad predictiva de secuelas significativas o muerte (P<0,001): ABC 0,92 ± 0,06, sensibilidad 84%, especificidad 100%, VPP 100%, VPN 77%.
Conclusiones. La β2-m en LCR es un adecuado biomarcador de la gravedad de la lesión cerebral asociada a la infección congénita sintomática por CMV. Su determinación combinada con las técnicas de neuroimagen maximiza la capacidad pronóstica a expensas de una mayor sensibilidad para predecir evolución adversa, sin detrimento de la especificidad.SUMMARY OF DOCTORAL THESIS: “CEREBROSPINAL FLUID BETA2-MICROGLOBULIN (CSF- β2-m) IN NEWBORNS WITH SYMPTOMATIC CONGENITAL CYTOMEGALOVIRUS INFECTION (SCCI): AN ACCURATE INDICATOR OF THE SEVERITY OF CENTRAL NERVOUS SYSTEM (CNS) INVOLVEMENT”
Ana Alarcón Allen
Introduction. In newborns with SCCI neuroimaging is the best predictor of long-term neurodevelopment. CSF findings have seldom been described. CSF-β2-m is increased in CNS infections.
Aims. (1) To determine whether CSF- β2-m is increased in newborns with SCCI, (2) to examine its correlation with neuroimaging and (3) to evaluate its ability to predict neurodevelopment.
Methods. All patients with SCCI born between 1993-2009 in La Paz University Hospital (Madrid) were included. A group of newborns who underwent CSF-β2-m determination as part of a sepsis/meningitis/meningoencephalitis workup and who finally had sterile cultures and a normal neurologic status comprised the control population. β2-m was measured by immunonephelometry. Neuroimaging was graduated by a validated scoring system (grades 0-3). Follow-up assessment included: neurologic examination and, if cerebral palsy, graduation by GMFCS, cognitive evaluation by BSID-III, WPPSI-III or WISC-IV, and behavioral assessment by ASEBA. Epilepsy, hearing or visual impairment were registered. For patients not contacted, follow-up data were obtained from the Neurology clinical records or from a parental interview. Neurologic disabilities were classified (grades 1-3).
Results. Twenty-six patients were included. Twenty had CSF-β2-m an all cases had neonatal neuroimaging. Three cases died, 20 surviving patients were evaluated according to our follow-up protocol and 3 had surrogate follow-up. β2-m was elevated in patients with SCCI with respect to the control group (median 7,2mg/L versus 1,6mg/L, P<0,001). Infants with severe neuroimaging abnormalities (grades 2-3) showed higher CSF-β2-m levels than those with grades 0-1 (P=0,007). Children who showed moderate-severe sequelae or died had higher β2-m concentrations (P=0,005). ROC analysis showed an area under the curve (AUC) of 0,84±0,08, and concentrations over 7,9mg/L predicted adverse outcome: sensitivity 69%, specificity 100%, PPV 100%, NPV 63%. Neuroimaging abnormalities grade 2-3 predicted moderate-severe disabilities or death (P=0,007): AUC 0,80±0,08, sensitivity 61%, specificity 100%, PPV 100%, NPV 53%. The combination of an elevated β2-m or neuroimaging grades 2-3 showed the highest predictive value for adverse outcome (P<0,001): AUC 0,92±0,06, sensitivity 84%, specificity 100%, PPV 100%, NPV 77%.
Conclusions. CSF-β2-m is an accurate biomarker of cerebral damage associated to SCCI. Its determination in combination with neuroimaging maximizes prognostic ability by increasing sensitivity without reducing specificity
Facing the Future: the Changing Shape of Academic Skills Support at Bournemouth University
No full textThis paper explores the potential impact of changes to higher education in England on student expectations, engagement, lifestyles and diversity, and outlines implications for the development of digital literacy within academic skills support at Bournemouth University (BU). We will investigate how tackling resource constraints with organisational change can also enable efficient, centralised provision of support materials that utilise networks to overcome the risk of fragmented support for digital literacy. We will also look at how changing delivery modes for support can accommodate changing student lifestyles whilst tackling a weakness of centralised support for digital literacy: that it can become detached from the student’s subject-focused academic practice. Finally we will explore how involving students in developing support can help us to face changes to student expectations and engagement whilst ensuring that materials are authentic and speak to learners in their own voice
El coste de uso del capital en la explicación del boom de la inversión europea de posguerra
No full textPost-war Europe provides an opportunity to study the importance of relative prices of capital, and the user cost of capital in particular, in explaining the convergence in investment rates between countries of similar "social capabilities" and income levels. After Second World War, at time as a new international order was established, European countries experienced a rapid process of income growth and convergence. In the interpretation of this process a prominent role has been attributed to technological progress and "catch-up" to the technological leader, the United States. Investment decisions are the way for embodying new technological progress, but investment takes place only when incentive exists. Among these incentives, recent empirical literature on economic growth highlights the role of relative prices of capital in explaining differences in investment rates and income growth between countries with very different income levels. But when we reduce the sample to countries closed in income levels and "social capabilities", we can demonstrate that, although the relative cost of capital converged over time and could help to explain income convergence, other factors were more significant in explaining the increase in investment rates. More important than the user cost of capital in the investment decision, was general prosperity caused by the demand increase
Habronyx (Habronyx) nigrifrons Alvarado, new species
No full text<i>Habronyx (Habronyx) nigrifrons</i> Alvarado, new species <p>(Figs. 4–6)</p> <p>Holotype: ♀, “ PERU: JU [Junín], Laguna Capilla 10o53’30”S / 75o57’01”W 4040 ♂, 16.iv.2012 J. Grados & I. Galindo” (MUSM).</p> <p>Paratypes: 3 ♀♀, same data as holotype (MUSM).</p> <p> <b>Diagnosis.</b> This species can be distinguished from other Neotropical congeners by the combination of the mesoscutellum and face predominantly black and the foveolate-reticulate integumental sculpture of the gena.</p> <p> <b>Description.</b> Female: Fore wing length 14 mm.</p> <p> <b>Head.</b> Mandibles stout, upper tooth stouter than, and about twice as long as lower tooth; lower face with strong punctures separated by 0.3–0.5x a puncture width, centrally convex, rather weakly narrowed ventrally with width across clypeal sulcus about 0.8–0.9x width across base of antennal toruli; clypeus smooth with isolated punctures, convex; frons areolate-rugulose, with weak median vertical carina; lateral ocellus separated from compound eye by 2.8–3.0x ocellar diameter; distance between ocelli 1.8x ocellar diameter; gena, in lateral view (measured perpendicularly to torulus), 1.0x as wide as compound eyes, gena punctate-reticulate grading to smooth between punctures on lower quarter, and next to compound eyes smooth; antenna with 38 flagellomeres.</p> <p> <b>Mesosoma.</b> Pronotum areolate-rugulose grading by lower third to areolate-rugulose; epomia present, upper third diverging from front margin and then forming a rounded corner as it curves back towards front margin; mesoscutum areolate-rugulose; notauli not distinct; mesoscutellum convex, reticulate, lateral carinae indistinct; mesopleuron punctulate-reticulate. Metapleuron and propodeum reticulate. Fore wing with distal abscissa of Rs 1.4–1.6x length of Rs+2r; 2+3rs-m 1.1–1.4x length of M between 2+3rs-m and 2m-cu. Hind wing with distal abscissa of Cu1 sclerotized throughout.</p> <p> <b>Metasoma.</b> Tergite I 0.8–0.9x length metafemur, smooth with isolated setae; tergite II+ smooth, with fairly thick, medium-length setae; ovipositor about 0.3x length of metatibia.</p> <p> <b>Color.</b> Head black with mandible apically, a spot on vertex (next to compound eyes), and on inner margin of gena (next to compound eyes) orange, and labium and face with lateral margins yellowish white. Mesosoma black except fore leg with femur, tibiae, basitarsi, second tarsomeres orange; mid leg with femur, tibiae, basitarsi, second tarsomeres orange; hind leg basal sixth of tibia and basal sixth of basitarsis orange. Metasoma black except apical third of tergite I, tergite II (narrowly black dorsally), tergite III and basally tergite IV orange. Ovipositor sheath black.</p> <p>♂: Unknown.</p> <p> <b>Etymology.</b> The specific epithet <i>nigrifrons</i> refers to the largely black coloration of face.</p> <p> <b>Comments.</b> One paratype has a white-yellowish spot in the center of the lower face.</p> <p> <b>Host.</b> <i>Habronyx (Habronyx) nigrifrons</i> was reared from pupae of the moth <i>Paracles tapina</i> (Dyar, 1913) (Erebidae: Arctiinae). Host larvae were found in the sounding area of the lake Capilla—Pasco department, after the rainy season when the peatlands are in climax. The larvae move easily through the water bodies, feeding on Juncaceae, probably <i>Juncus ebracteatus</i> E. Mey. Larvae belonging to the genus <i>Paracles</i> (Walker) have been previously reported inhabiting aquatic environments in Argentina and Brazil like <i>P. azollae</i> (Berg, 1877), <i>P. tenuis</i> (Berg, 1877) and <i>P. klagesi</i> (Rothschild, 1910) (Berg 1877; Meneses 2013). The moth pupae were found in groups under rocks (Fig. 10) in elevated areas in each locality, usually dark and humid places. Pupae and larvae (in the last instar) were collected and reared; from one group of pupae the wasps described here and one adult moth emerged.</p> <p> Previously, <i>P. tapina</i> was known from a single adult male collected in Coropuna, Arequipa, Peru, at 4419 m during October 1911 (Dyar 1913); its distribution is expanded in Peru to include the departments of Arequipa, Junín, and Pasco (Fig. 17). Additionally, this is the first time that the larvae (Figs. 9–10), pupae (Fig. 11) and adult female are recorded. Females (Fig. 8) are slightly larger than males (Fig. 7), female fore wing measures 18–21mm (n=5) and males measure 15mm (n=1); coloration of the fore wings in females is clearer and have whitish setae on the dorsal and ventral part of the last two abdominal segments.</p> <p> This is not the first time that an arctiine has been registered as a host for species of <i>Habronyx</i>, but it is the first record of a Neotropical species attacking this group. The European species <i>H. (C.) perspicuus</i> (Wesmael, 1849) was found parasitizing <i>Cymbalophora pudica</i> (Esper, 1784) (Yu <i>et al</i>. 2005).</p> <p> <b>PLATE 2 FIGURES 4–6.</b> Details of <i>Habronyx (Habronyx) nigrifrons</i> Alvarado, new species. <b>4.</b> Lateral habitus (scale = 1 mm) <b>5.</b> Facial view <b>6.</b> Mesosoma, in lateral view.</p> <p> <b>Material studied.</b> ♀, “ PERU: JU [Junín department], Laguna Capilla 10o53’30”S / 75o57’01”W 4040 m, 16.iv.2012 J. Grados & I. Galindo”; 3♀♀, “ PERU: PA [Pasco department] Río Gayco, 10o50’13”S / 75o57’43”W 4323m 13–14.vi.2012 J. Grados & I. Galindo” (Fig. 17); ♀, “ PERU: PA [Pasco department], Laguna Aguascancha 10º51’58”S / 75º56’10”W 4170m 15.iv.2012 J. Grados & I. Galindo”; ♂ “ PERU, PA. Río Gayco 10º48'48'' S / 75º48'54'' W 4323 m 13–14.vi.2012 J. Grados & I. Galindo”; 2 ♂♂ “ PERU: Dpto. [Department] Huancavelica, cerca a Pariona, 4000 m, larva colectada el 25.v.2002, adulto recuperado el 15.vi.2002, P. Hocking”; 2♂♂ “ PERU: AR [Arequipa department], Quebrada Chacnia, 4805 m, 14o46’11.9’’S / 72o22’38.1’’W, 18.viii.2011, E. Rázuri” (MUSM).</p> <p> <b>PLATE 3 FIGURES 7–12.</b> Details of <i>Paracles tapina.</i> <b>7.</b> Habitus of male, dorsal view at right, ventral view at left (scale = 10 mm) <b>8.</b> Habitus of female, dorsal view at right, ventral view at left (scale = 10 mm) <b>9–11.</b> Larvae in habitat, photograph taken in surrounding of Capilla Lake <b>12.</b> Pupae found under rocks, photograph taken in surrounding of Capilla Lake.</p>Published as part of <i>Alvarado, Mabel & Grados, Juan, 2015, Habronyx Förster (Hymenoptera: Ichneumonidae: Anomaloninae) in Peru and Ecuador: three new species, a range extension, and a new host record in Zootaxa 3937 (1)</i>, DOI: 10.11646/zootaxa.3937.1.2, <a href="http://zenodo.org/record/246069">http://zenodo.org/record/246069</a>
Evaluación agroeconómica del diseño de siembra, poblaciones y cultivares de lechuga durante la época lluviosa bajo condiciones de El Zamorano
No full text30 p.El ensayo se realizó en los terrenos de la unidad de producción Hortícola de la Escuela Agrícola Panamericana. El Zamorano, que se encuentra ubicado en el valle del rio Yegüare, Honduras a 14 grados Latitud norte y 87 grados longitud oeste, y a 800 msnm. La temperatura media anual histórica es de 24.2 o C con una precipitación media anual de 1,100 mm. Los tratamientos se hicieron en una parcela de 44 m de largo por 21.6 m de ancho que en total ocupó 950.4 m2, la cual se dividió según el ancho de cama (0.90 m y 1.80 m) en cuatro repeticiones o bloques. Los bloques contaban con ocho tratamientos que tenían camas de 5 m de largo con el ancho mencionado según el diseño. Entre cada bloque se dejó una separación de un metro que se usó como calle y separador de tratamientos. El objetivo del estudio fue determinar el efecto de la distancia: entre plantas, diseño parcial y los cultivares sobre los rendimientos técnicos y económicos del cultivo. Se concluyó que el cultivar Ithaca se adaptó mejor a las condiciones de El Zamorano, dando como resultado una mejor formación y compactación de la cabeza en menos tiempo (35 días de trasplante hasta cosecha) la comparación del cultivar Empeor que solo formó pero no compactó la cabeza. Para este ensayo el mejor tratamiento para las variables medidas: número total de cabezas, peso total, número de cabezas comerciales y peso comercial, fue con una distancia entre plantas de 0.25m, diseño de cama de 1.80 m de ancho y el cultivar Ithaca, además, se obtuvo mayor beneficia neto con el mismo tratamiento, en comparación a los tratamientos alternativos
DISEÑO E IMPLEMENTACIÓN DE UN ROBOT MANIPULADOR DE CINCO GRADOS DE LIBERTAD PARA UNA ESTACIÓN DE TRABAJO DIDÁCTICA
No full textThis article is based on the design and construction of an anthropomorphic or manipulator robot of five degrees of freedom for a workstation with didactic purposes. The manipulator robot can be operated locally from the workstation, and remotely through a mobile application. The constructive design was developed using CAD (Computer-Aided Design) tools and its control was realized by programming developed in free software. In addition, the description of the direct kinematic model is showed.
Key words: Anthropomorphic robot, direct kinematics, degrees of freedom, robotic manipulator.
References
[1] L. Cehovin, A. Rezelj, and D. Skocaj, “Open-Source Robotic Manipulator and Sensory Platform,” vol. 457, 2017.
[2] M. Cakir and E. Butun, “An educational tool for 6-DOF industrial robots with quaternion algebra”, Comput. Appl. Eng. Educ., vol. 15, no. 2, pp. 143–154, 2007.
[3] A. Gil, O. Reinoso, J. M. Marin, L. Paya, and J. Ruiz, “Development and deployment of a new robotics toolbox for education”, Comput. Appl. Eng. Educ., vol. 23, no. 3, pp. 443–454, 2015.
[4] A. H. Odorico and M. Teórico, “La robótica desde una perspectiva pedagógica”, Vol. 2, no. 5, pp. 33–48, 2005.
[5] S. Jung, “Experiences in developing an experimental robotics course program for undergraduate education”, IEEE Trans. Educ., vol. 56, no. 1, pp. 129–136, 2013.
[6] K. Subir, “Introducción a la Robótica”, México: Mc-Graw, 2008.
[7] A. Ollero, “Robótica Manipuladores y robots móviles”, Barcelona, España: Alfaomega - Marcombo, 2001.
[8] J. J. Craig, “Robótica”, 3era Ed., vol. 1, no. 8020. México: Pearson Education, 2006.
[9] J. Denavit and R. S. Hartenberg, “A kinematic notation for lower pair mechanisms based on matrices.,” J. Appl. Mech., vol. 77, pp. 215–221, 1955.
[10] A. Barrientos, L. Penín, C. Balaguer, and R. Aracil, “Fundamentos de Robótica”, Madrid, España: McGraw de España, 2007.
[11] M. Spong, S. Hutchinson, and M. Vidsayagar, “Robot Modeling and Control”, First Edit. Ed. Weley New York: 1989.
Este artículo se basa en el diseño y construcción de un robot manipulador o antropomórfico de cinco grados de libertad para una estación de trabajo con fines didácticos. El robot manipulador puede ser operado de manera local, desde la estación de trabajo y de manera remota mediante una aplicación móvil. El diseño constructivo se desarrolló usando herramientas CAD (Computer-Aided Design) y su control se realizó mediante programación desarrollada en software libre. Además, se presenta la descripción del modelo cinemático directo.
Palabras Clave: Cinemática directa, grados de libertad, robot antropomórfico, robot manipulador.
Referencias
[1] L. Cehovin, A. Rezelj, y D. Skocaj, “Open-Source Robotic Manipulator and Sensory Platform,” vol. 457, 2017.
[2] M. Cakir and E. Butun, “An educational tool for 6-DOF industrial robots with quaternion algebra”, Comput. Appl. Eng. Educ., vol. 15, no. 2, pp. 143–154, 2007.
[3] A. Gil, O. Reinoso, J. M. Marin, L. Paya, y J. Ruiz, “Development and deployment of a new robotics toolbox for education”, Comput. Appl. Eng. Educ., vol. 23, no. 3, pp. 443–454, 2015.
[4] A. H. Odorico y M. Teórico, “La robótica desde una perspectiva pedagógica”, Vol. 2, no. 5, pp. 33–48, 2005.
[5] S. Jung, “Experiences in developing an experimental robotics course program for undergraduate education”, IEEE Trans. Educ., vol. 56, no. 1, pp. 129–136, 2013.
[6] K. Subir, “Introducción a la Robótica”, México: Mc-Graw, 2008.
[7] A. Ollero, “Robótica Manipuladores y robots móviles”, Barcelona, España: Alfaomega - Marcombo, 2001.
[8] J. J. Craig, “Robótica”, 3era Ed., vol. 1, no. 8020. México: Pearson Education, 2006.
[9] J. Denavit y R. S. Hartenberg, “A kinematic notation for lower pair mechanisms based on matrices.,” J. Appl. Mech., vol. 77, pp. 215–221, 1955.
[10] A. Barrientos, L. Penín, C. Balaguer, y R. Aracil, “Fundamentos de Robótica”, Madrid, España: McGraw de España, 2007.
[11] M. Spong, S. Hutchinson, y M. Vidsayagar, “Robot Modeling and Control”, First Edit. Ed. Weley New York: 1989
University senior students on the web
No full textThe Internet is increasingly prominent in all walks of life, and Web connection is a key factor in social integration. The rise in life expectancy and quality of life mean that our active seniors now represent a growing sector in society. This study analyses what senior citizens use the Internet for and why, as well as the main benefits of its usage and the perceived obstacles of those who are non-users. The results derive from a questionnaire completed by senior citizens enrolled on university courses for older people, and they show that university seniors frequently connect to the Internet –daily or 2 or 3 times per week–, and use it mainly to look up facts, contact family and friends, for course work and to read the press. They consider the Internet easy to use but they could survive without it. For those who do not have access to the Internet, lack of knowledge about how to use it is the main barrier; yet they do not consider themselves incapable of learning how to use the Internet if they wished to do so. The data gathered from the survey challenge negative stereotypes of older people, and encourage us to modify our view of active seniors as disconnected from and incapable of using the Web and instead see their progress and motivation to learn as something highly positive
Do aluminum (Al)-hyperaccumulator and phosphorus (P)-solubilising species assist neighbouring plants sensitive to Al toxicity and P deficiency?
No full textEl autor(es) declara haber recibido apoyo financiero para la investigación, autoría y/o publicación de este artículo. Este estudio fue financiado por la Agencia Nacional de Investigación y Desarrollo (ANID) del gobierno de Chile a través del proyecto de inicio FONDECYT No 11170368 (MD), 11220462 (GB), 11200377 (PB), FONDECYT Proyectos regulares No 1210684 (MD), 1211856 (MR-D), 1241293 (PB), ANID/FONDAP/15130015 (MR-D), Proyecto Anillo de Investigación en Áreas Temáticas Específicas ATE220038 (MD, PD y PB), ATE230007 (MD y MR-D). También agradecemos a la Dirección de Investigación de la Universidad de La Frontera (DiUFRO) por su apoyo a través del Proyecto de Investigación Vinculados a la Red Nexer No. DNX22-0009 (MD y PB).r Los autores declaran que recibieron apoyo financiero para la investigación, autoría y/o publicación de este artículo. Este estudio fue financiado por la Agencia Nacional de Investigación y Desarrollo (ANID) del gobierno de Chile a través del proyecto de inicio FONDECYT N grados 11170368 (MD), 11220462 (GB), 11200377 (PB), proyectos FONDECYT Regulares N grados 1210684 (MD), 1211856 (MR-D), 1241293 (PB), ANID/FONDAP/15130015 (MR-D), Proyecto Anillo de Investigación en Áreas Temáticas Específicas ATE220038 (MD, PD y PB), ATE230007 (MD y MR-D). También agradecemos a la Dirección de Investigación de la Universidad de La Frontera (DiUFRO) por su apoyo a través del Proyecto de Investigación Vinculados a la Red Nexer No. DNX22-0009 (MD y PB)
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