1,547 research outputs found
Two new genera of hispines (Coleoptera: Chrysomelidae: Cassidinae) from Ecuador
Bicristispa gracilis, new genus and new species, and Orbispa confluens, new genus and new species
(Coleoptera: Chrysomelidae: Cassidinae), both from canopy fogging material from Ecuador are described and
illustrated. Comparative notes distinguishing them from similar genera are provided
Repeating platinum/bevacizumab in recurrent or progressive cervical cancer yields marginal survival benefits
Our objective was to assess overall survival of cervical cancer patients following prior platinum/bevacizumab chemotherapy, comparing retreatment with platinum/bevacizumab with alternative therapies.
A retrospective analysis was performed of women who received platinum/bevacizumab (PB) chemotherapy for cervical cancer at Washington University between July 1, 2005 and December 31, 2015. Wilcoxon rank-sum exact test and Fisher's exact test were used to compare the treatment groups, and Kaplan Meier curves were generated. Cox regression analyses were performed, with treatment free interval and prior therapy response included as covariates.
Of 84 patients who received PB chemotherapy, 59 (70%) received no second line chemotherapy, as they did not recur, progressed without further chemotherapy, were lost to follow up, or expired. Of the remaining 25 patients, 9 were retreated with the combination of platinum/bevacizumab (PB), 6 were retreated with a platinum regimen without bevacizumab (P), and 10 were retreated with neither (not-P). The only long-term survivor was in the not-P group and was treated with an immunotherapy agent. Median overall survival of all patients was 7.1 months. There was a marginal difference in survival between women in the PB and not-PB groups (11.8 versus 5.7 months; HR 3.02, 95% CI, 0.98–9.28). There was no difference in survival based on platinum interval (HR 0.81; 95% CI, 0.27–2.45).
Outcomes are grim for women retreated after platinum/bevacizumab therapy and are only marginally improved by retreatment with a platinum/bevacizumab regimen. Rather than additional PB therapy, women with cervical cancer who recur after platinum/bevacizumab should consider supportive care or clinical trials
Unwebbing the Presynaptic Web
AbstractThe release of neurotransmitter from nerve terminals occurs at a specialized region of the presynaptic plasma membrane called the active zone. A dense matrix of proteins associated with the active zone, called the presynaptic web, is thought to play a fundamental role in defining these neurotransmitter release sites. In this issue of Neuron, Phillips et al. have identified conditions for the biochemical purification of the presynaptic web and show that the web is comprised of proteins involved in the docking, fusion, and recycling of synaptic vesicles
Modeling wave propagation through an analytical surface model
Nowadays there is a certain development in the use of railway, especially in the form of trams and underground lines in urban areas. Despite its many advantages, this kind of transport is a significant source of vibrations, which may affect residents and buildings near to the track. Wave transmission through the ground is therefore a phenomenon of particular interest. The object of this article is to formulate and test an analytical model of vibration propagation through the terrain surface. The model is based on the wave equation and takes into account wave scattering and reflection in the interfaces between different soil layers. A sensitivity analysis of its main parameters is carried out, and then a comprehensive set of simulations is made to test model performance and analyze factors such as load magnitude and velocity or soil configuration. The model has proved to be an interesting instrument to study the vibration phenomenon from a theoretical point of view and some improvements are proposed to turn it into a tool for engineers and designers
A minor-merger origin for inner disks and rings in early-type galaxies
Nuclear disks and rings are frequent galaxy substructures, for a wide range
of morphological types (from S0 to Sc). We have investigated the possible
minor-merger origin of inner disks and rings in spiral galaxies through
collisionless N-body simulations. The models confirm that minor mergers can
drive the formation of thin, kinematically-cold structures in the center of
galaxies out of satellite material, without requiring the previous formation of
a bar. Satellite core particles tend to be deposited in circular orbits in the
central potential, due to the strong circularization experienced by the
satellite orbit through dynamical friction. The material of the satellite core
reaches the remnant center if satellites are dense or massive, building up a
thin inner disk; whereas it is fully disrupted before reaching the center in
the case of low-mass satellites, creating an inner ring instead.Comment: 2 pages, 2 figures, Proceedings of the conference "Hunting for the
Dark: The Hidden Side of Galaxy Formation", held in Malta, 19-23 Oct. 2009,
ed. V. Debattista and C. C. Popescu, AIP Conf. Ser., in pres
Evolution along the sequence of S0 Hubble types induced by dry minor mergers. II - Bulge-disk coupling in the photometric relations through merger-induced internal secular evolution
Galaxy mergers are considered as questionable mechanisms for the evolution of
lenticular galaxies (S0's), on the basis that even minor ones induce structural
changes that are difficult to reconcile with the strong bulge-disk coupling
observed in the photometric scaling relations of S0's. We check if the
evolution induced onto S0's by dry intermediate and minor mergers can reproduce
their photometric scaling relations, analysing the bulge-disk decompositions of
the merger simulations presented in Eliche-Moral et al. (2012). The mergers
induce an evolution in the photometric planes compatible with the data of S0's,
even in those ones indicating a strong bulge-disk coupling. The mergers drive
the formation of the observed photometric relation in some cases, whereas they
induce a slight dispersion compatible with data in others. Therefore, this
evolutionary mechanism tends to preserve these scaling relations. In those
photometric planes where the morphological types segregate, the mergers always
induce evolution towards the region populated by S0's. The structural coupling
of the bulge and the disk is preserved or reinforced because the mergers
trigger internal secular processes in the primary disk that induce significant
bulge growth, even although these models do not induce bars. Intermediate and
minor mergers can thus be considered as plausible mechanisms for the evolution
of S0's attending to their photometric scaling relations, as they can preserve
and even strengthen any pre-existing structural bulge-disk coupling, triggering
significant internal secular evolution (even in the absence of bars or
dissipational effects). This means that it may be difficult to isolate the
effects of pure internal secular evolution from those of the merger-driven one
in present-day early-type disks (abridged).Comment: Accepted for publication in Astronomy & Astrophysics, 13 pages, 8
figures. Definitive version after proofs. Added references and corrected
typo
Effectiveness of environmental impact statement methods: A Colombian case study
Funding for open access charge: Universidad de Granada/CBUA. The authors also appreciate the support of the research group TEP-968 (Technologies for Circular Economy) of the University of Granada (Spain) .The effectiveness of impact assessment (IA) methods has been a neglected topic in procedural effectiveness
research, which has placed higher relevance on the quality of Environmental Impact Statements (EISs) and the
environment impact assessment (EIA) process in general. This study analysed the effectiveness of methods used
in IA in Colombia to demonstrate that they have been used in compliance with the Terms of Reference (ToR) but
did not analyse their effectiveness. A total of 131 EIS were analysed using a revised version of the Effectiveness
Index for Environmental Impact Assessment Methods (EIM) proposed by Caro and Toro (2016). It is concluded
that, even if the environmental authority has accepted the EIS as a requirement for obtaining an environmental
license, most of the methods that have been used in these technical documents, obtained a medium or low degree
of effectiveness. The parameters regulated for the law have a higher percentage of compliance. The analysis
suggests that the guidelines provided for the law, related to the design and implementation of the methods,
should be improved to develop an effective EIA.Universidad de Granada/CBUAUniversity of Granada (Spain) TEP-96
ED018. Diagnóstico de listados de mariposas diurnas (Papilionoidea) mediante el uso de iNaturalist en Ecuador
Developing biological checklists as complementary tools for the development and support of monitoring programs and management plans is essential to generate awareness aiming at conservation. Butterflies constitute an essential bioindicator group for determining the state of conservation of environments. Diurnal butterflies (Papilionoidea), in this sense, could be a good indicator based on the observations of this group uploaded to the iNaturalist platform due to their relatively easy identification, given mainly by the color pattern of their wings. This analysis sought to evaluate the power of citizen science as an alternative and complementary source for the generation of diurnal butterfly’s checklists. Species accumulation curves were used to estimate the progress status of these checklists on the platform. It was found that the checklists of protected areas such as Yasunà National Park and Cuyabeno Faunistic Reserve have information gaps on the platform despite their high biodiversity. The difference may lie in technological limitations that prevent the correct use of the platform and a waste of its real capacity. In addition, a notable difference was evidenced in the number of observations loaded for this taxon versus the number of observations loaded with research grade, for which a greater effort to curate observations by the community of specialists is recommended. This analysis points to collaborate in the elaboration of diurnal butterfly identification guides in the future, as well as contributing to long-term monitoring programs with the active participation of citizens.Desarrollar listados biológicos como herramientas complementarias para el desarrollo y acompañamiento de programas de monitoreo y planes de manejo es esencial para generar conciencia con miras a la conservación. Las mariposas constituyen un grupo bioindicador por excelencia para determinar el estado de conservación de los ecosistemas. Las mariposas diurnas (Papilionoidea), en ese sentido, podrÃan ser un buen indicador basándose en las observaciones de este grupo cargadas en la plataforma iNaturalist por su relativamente fácil identificación dada mayormente por el patrón de coloración de sus alas. Este análisis buscó evaluar el poder de la ciencia ciudadana como una fuente alternativa y complementaria para la generación de listados de mariposas diurnas. Se utilizó curvas de acumulación de especies para estimar el estado del avance de estos listados en la plataforma. Se encontró que los listados de áreas protegidas como el Parque Nacional Yasunà y la Reserva FaunÃstica Cuyabeno presentan vacÃos de información en la plataforma a pesar de su alta biodiversidad. La diferencia puede radicar limitaciones tecnológicas que impiden el uso correcto de la plataforma y un desaprovechamiento de su real capacidad. Además, se evidenció una notable diferencia en el número de observaciones cargadas para este taxón en relación con el número de observaciones cargadas con grado de investigación, por lo que se recomienda un mayor esfuerzo de curación de observaciones por parte de la comunidad de especialistas. Este análisis apunta en un futuro a colaborar en la elaboración de guÃas de identificación de mariposas diurnas, asà como contribuir en programas de monitoreo a largo plazo con la participación de los ciudadanos
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