1,309 research outputs found
Management of introduced animals in Galapagos
We review programmes to control or eradicate introduced vertebrates and invertebrates in Galapagos
Endemic Galapagos Tree Daisy Scalesia pedunculata Threatened by Competition with Nonnative Blackberry Rubus niveus
There is a debate whether invasive plants can induce extinction debt in native flora that is not immediately obvious. Competitive effects of invasions and how competition causes native biodiversity loss are complicated to evaluate. Experi-mental removal or introduction bears the most promise of demonstrating native species displacement mechanics. Over an eight- year period, we followed plots in the only remaining Scalesia pedunculata forest on Santa Cruz Island, Galapagos, where invading Rubus niveus was either removed or retained. Demographic param-eters and total recruitment failure in the presence of R. niveus suggest that S. pedun-culata may face local extinction in two decades without invasion management
One-dimensional modelling of the thinning of particulate suspensions near pinch-off
This paper deals with the thinning dynamics of a liquid bridge of dilute particulate suspensions in a Newtonian matrix. We describe the final stage before break-up of a colloidal suspension, which occurs in a liquid thread between two confining beads. The model, based on the one-dimensional mass and momentum conservation equations, shows quantitative agreement with the experimentally observed deceleration and final pinching behaviour of the medium between individually monitored particles in the suspension (Mathues et al., 2015) and thus supports the hypothesis that an accelerated thinning of the Newtonian matrix is caused by an active stretching via independently moving particles.Spanish MINECO [projects nos. DPI2014-59292-C03-01-P, DP12014-59292-C03-03-P, DPI2015-71901-REDT, DPI2017-88201-C3-2-R and DP12017-88201-C3-3-R]. These research projects have been partly financed through European funds. WM and CC would like to thank support from the ERC starting grant [no. 203043 NANOFIB] and the Research Foundation Flanders [FWO project G077916N]
Aural fullness and transtympanic ventilation tubes in Ménière's disease: a scoping review
Background: Ménière’s Disease (MD) often presents with aural fullness, for reasons that are currently not well understood. Insertion of transtympanic ventilation tubes (VTs) has been historically used for the management of this symptom, though the nature and mechanism of effectiveness is unclear. Objectives: To give an overview of the data available on the effects of VT insertion on aural fullness in MD. Methods: The databases PubMed, EMBASE, Medline, SCOPUS, Web of Science, CENTRAL and Google Scholar were searched to identify relevant records. Records were subsequently analysed and data extracted. Results: Only two studies directly measured the effect of VT insertion on aural fullness, while three others measured it as a placebo to another treatment. Considerable heterogeneity was found among the studies, including conflicting conclusions. Conclusions: There is a paucity of evidence investigating the effect of grommet insertion on aural fullness in MD. This work directs future research into this topic
PRINCIPIO DE IMPARCIALIDAD DE LOS SERVIDORES POLICIALES
En Ecuador, el Estado asumió la responsabilidad de garantizar el correcto desempeño de las funciones policiales de acuerdo a la Constitución de la República del Ecuador, la imparcialidad en el accionar policial ha dado paso a varios comentarios y críticas positivas y negativas por parte de la sociedad, pues se ha observado que en ciertos sectores los habitantes han evidenciado la corrupción que existe en los procedimientos policiales, donde muchas veces se ha beneficiado una o más personas. En este sentido, la investigación tiene como objetivo general demostrar si la imparcialidad se logra únicamente con la objetividad y neutralidad en el desempeño de las funciones policiales para evitar favorecer indebidamente a persona o grupo alguno. La encuesta y la entrevista han sido los métodos aplicados en la presente investigación, lo que ha permitido concluir que la imparcialidad no únicamente depende de la objetividad y neutralidad, sino de varios factores descritos en la misma
Las Relaciones Económicas y Políticas entre Honduras y Cuba desde 1876 a 1887.
El Trabajo de Fin de Máster que aquí se presenta es un estudio de carácter histórico que busca conocer las relaciones económicas y políticas entre Honduras y Cuba en los años de 1876 a 1887, coincidiendo con la Reforma Liberal de Honduras y el proceso de Independencia de Cuba. Como uno de sus objetivos se tratará de identificar a los cubanos que participaron activamente en la vida política de Honduras y los cargos que ocuparon durante los gobiernos reformistas. Igualmente, se intentará describir los factores que estimularon el comercio -fundamentalmente de ganado- entre las dos naciones.
Para conseguir tales metas, se han utilizado documentos oficiales, Acuerdos, Leyes, Decretos, además de fuentes hemerográficas y obras bibliográficas relacionadas con el tema. Para el manejo de los datos se han utilizado el programa Zotero, como gestor bibliográfico, y Filemaker Pro como gestor de fuentes hemerográficas. Todo ello nos permite concluir que, aunque los gobiernos liberales implementaron políticas para incentivar y mejorar el comercio y las relaciones entre ambos, no lograron los resultados esperados debido a las circunstancias de inestabilidad política y crisis económica que estaban produciéndose en los dos territorios y también fue determinante en el fracaso el interés personal de los gobernantes hondureños por participar en las inversiones extranjeras propuestas por el capital transnacional.The Master’s Thesis presented here is a historical study that seeks to know the economic and political relations between Honduras and Cuba from 1876 to 1887, coinciding with the Liberal Reform of Honduras and the process of Cuban Independence. One of the objectives of this work will be to try to identify the Cubans who actively participated in the political life of Honduras and the positions they held during the reformist governments. Likewise, an attempt will be made to describe the factors that stimulated trade —mainly cattle trade— between the two nations.
To achieve these goals, official documents, agreements, laws, decrees, as well as newspaper sources and hemerografic and bibliographic works related to the subject have been used. For data management, the Software Zotero has been used as a bibliographic manager, and the program FileMaker Pro as a manager of hemerographic sources. All this allows us to conclude that, although the liberal governments implemented policies to encourage and improve trade and relations between the two countries, they did not achieve the expected results due to the circumstances of political instability and economic crisis that were occurring in the two territories, and the personal interest of the Honduran presidents to participate in foreign investments proposed by transnational capital was also a determining factor in the failure.Máster en Investigación de la Comunicación como Agente Histórico-Socia
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Object detection networks and augmented reality for cellular detection in fluorescence microscopy
Object detection networks are high-performance algorithms famously applied to the task of identifying and localizing objects in photography images. We demonstrate their application for the classification and localization of cells in fluorescence microscopy by benchmarking four leading object detection algorithms across multiple challenging 2D microscopy datasets. Furthermore we develop and demonstrate an algorithm that can localize and image cells in 3D, in close to real time, at the microscope using widely available and inexpensive hardware. Furthermore, we exploit the fast processing of these networks and develop a simple and effective augmented reality (AR) system for fluorescence microscopy systems using a display screen and back-projection onto the eyepiece. We show that it is possible to achieve very high classification accuracy using datasets with as few as 26 images present. Using our approach, it is possible for relatively nonskilled users to automate detection of cell classes with a variety of appearances and enable new avenues for automation of fluorescence microscopy acquisition pipelines. © 2020 Waithe et al
Enantioselective transformations of 5-hydroxymethylfurfural via catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides
A catalytic asymmetric 1,3-dipolar cycloaddition between iminoesters derived from 5-hydroxymethylfurfural (HMF) and different activated alkenes is reported. Excellent levels of diastereo and enantioselectivity were obtained when Fesulphos/CuI complex was used as catalyst. This metodology provides an effective and sustainable access to challenging enantioenriched heterocyclic scaffolds and represents one of the rare examples of catalytic asymmetric transformations using HMF as a starting materialPID2020-113059GB-C22, B2017/BMD- 3867 RENIMC
Limited natural regeneration of unique Scalesia forest following invasive plant removal in Galapagos
More than 60% of the flora of the Galapagos Islands is introduced and some of these species have become invasive, severely altering ecosystems. An example of an affected ecosystem is the Scalesia forest, originally dominated by the endemic giant daisy tree Scalesia pedunculata (Asteraceae). The remnant patches of this unique forest are increasingly being invaded by introduced plants, mainly by Rubus niveus (blackberry, Rosaceae). To help large-scale restoration of this ecologically important forest, we seek to better understand the natural regeneration of S. pedunculata after invasive plant control. We monitored naturally recruited S. pedunculata saplings and young trees over five years in an area where invasive plant species are continuously being removed by manual means. We measured survival, height and growth of S. pedunculata saplings and young trees along permanent transects. Percent cover of surrounding plant species and of canopy shade directly above each S. pedunculata individual were determined, as well as distance to the next mature S. pedunculata tree. We identified potential factors influencing initial sapling survival and growth by applying generalized linear models. Results showed a rapid growth of saplings and young trees of up to 0.45 cm per day and a high mortality rate, as is typical for pioneer species like S. pedunculata. Sapling survival, growth and mortality seemed to be influenced by light availability, surrounding vegetation and distance to the next adult S. pedunculata tree. We concluded that natural regeneration of S. pedunculata was high only five months after the last herbicide application but that 95% of these recruits had died over the 5-year period. Further studies are needed to corroborate whether the number of surviving trees is sufficient to replace the aging adult trees and this way maintain remnants of the Scalesia forest. Urgent action is needed to help improve future restoration strategies to prevent further degradation of this rapidly shrinking threatened forest ecosystem
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