448 research outputs found
GraCT: A Grammar based Compressed representation of Trajectories
We present a compressed data structure to store free trajectories of moving
objects (ships over the sea, for example) allowing spatio-temporal queries. Our
method, GraCT, uses a -tree to store the absolute positions of all objects
at regular time intervals (snapshots), whereas the positions between snapshots
are represented as logs of relative movements compressed with Re-Pair. Our
experimental evaluation shows important savings in space and time with respect
to a fair baseline.Comment: This research has received funding from the European Union's Horizon
2020 research and innovation programme under the Marie Sk{\l}odowska-Curie
Actions H2020-MSCA-RISE-2015 BIRDS GA No. 69094
Understanding seed dormancy and germination aids conservation of rainforest species from tropical montane cloud forest: a case study confirming morphophysiological dormancy in the genus Tasmannia
Context: Seed dormancy is one issue hindering implementation of conservation actions for rainforest species.
Aims: We studied dormancy and germination in Tasmannia sp. Mt Bellenden Ker and Tasmannia membranea, two tropical montane rainforest species threatened by climate change, to develop a better understanding of dormancy in the species and the genus.
Methods: Dormancy was classified for T. sp. Mt Bellenden Ker on the basis of an imbibition test, analysis of embryo to seed length (E:S) ratios and germination in response to the following four dormancy-breaking treatments: (I) scarification of the seedcoat near the micropylar end; (2) removal of the seedcoat; (3) application of 100 mg L(-1)or (4) 500 mg L-1 gibberellic acid. The most effective treatment was then tested on T. membranea. The requirement for light for germination was also assessed.
Key results: Both scarified and intact seeds imbibed water. Initial E:S ratios were <0.22 for both species and increased up to 0.74 after 40 days, just before radicle emergence, for T. sp. Mt Bellenden Ker. Germination proportions were significantly higher in Treatments 1 and 2 than the remaining treatments for T. sp. Mt Bellenden Ker; T. membranea responded similarly well to Treatment 1. Germination under alternating light/dark conditions was slightly, but not significantly, greater than germination in the dark alone.
Conclusions: Both species have morphophysiological dormancy and treatments that remove seedcoat resistance to embryo growth facilitate germination. These treatments may improve germination in other species from the genus Tasmannia.
Implications: This knowledge will aid the germination of seeds to implement conservation strategies for Tasmannia spp
Sunlight and red to far-red ratio impact germination of tropical montane cloud forest species
Context: Australiaâs tropical montane cloud forests (TMCF) exhibit exceptional species richness and endemism. Determinants of regeneration via seed of these species are next to unknown, limiting our ability to quantify and project their vulnerability to climate change. The ratio of red to far-red light (R:FR) has been shown to influence seed germination of many tropical species.Aims: We investigated germination of six previously unstudied TMCF species in relation to the presence or absence of light (light/dark) and light quality (R:FR). We hypothesised that increased R:FR would lead to increased germination and that small-seeded species would be more likely to have a light requirement and be less sensitive to R:FR compared to larger-seeded species.Methods: Sunlight and polyester filters were used to create a gradient of R:FR ranging from 0.1 to 1.14. Seeds were also sown in constant darkness.Key results: Across species we saw varying germination responses. Three of the four smallest-seeded species exhibited an absolute light requirement for germination and did not discriminate between different R:FR. Germination of the small-seeded TMCF endemic Dracophyllum increased exponentially with increasing R:FR. Germination of the largest-seeded species was inhibited by both low and high R:FR, and germination was higher in constant darkness than diurnal light/dark. All six species were able to germinate at remarkably low R:FR values.Conclusions: Light affects seed germination of Australiaâs TMCF plant species in a variety of ways.Implications: The findings of this study provide insights into plant recruitment in situ, and the acclimation potential of these species under reduced R:FR predicted for the future
Lung Transplant Improves Survival and Quality of Life Regardless of Telomere Dysfunction
Trasplante de pulmĂłn; Fibrosis pulmonar; Trastornos de los telĂłmerosTrasplantament pulmonar; Fibrosi pulmonar; Trastorns dels telĂČmersLung transplantation; Pulmonary fibrosis; Telomere disordersIntroduction: Fibrotic interstitial lung diseases (ILDs) are the first indication for lung transplantation (LT). Telomere dysfunction has been associated with poor post-transplant outcomes. The aim of the study was to evaluate the morbi-mortality and quality of life in fibrotic ILDs after lung transplant depending on telomere biology.
Methods: Fibrotic ILD patients that underwent lung transplant were allocated to two arms; with or without telomere dysfunction at diagnosis based on the telomere length and telomerase related gene mutations revealed by whole-exome sequencing. Post-transplant evaluation included: (1) short and long-term mortality and complications and (2) quality of life.
Results: Fifty-five percent of patients that underwent LT carried rare coding mutations in telomerase-related genes. Patients with telomere shortening more frequently needed extracorporeal circulation and presented a higher rate of early post-transplant hematological complications, longer stay in the intensive care unit (ICU), and a higher number of long-term hospital admissions. However, post-transplant 1-year survival was higher than 80% regardless of telomere dysfunction, with improvement in the quality of life and oxygen therapy withdrawal.
Conclusions: Post-transplant morbidity is higher in patients with telomere dysfunction and differs according to elapsed time from transplantation. However, lung transplant improves survival and quality of life and the associated complications are manageable.This study was funded by Instituto de Salud Carlos III through project PI18/00367 (Co-funded by European Regional Development Fund, ERDF, a way to build Europe), Spanish Society of Respiratory (SEPAR), Barcelona Respiratory Network (BRN), and FundaciĂł RamĂłn Pla Armengol. RP laboratory was funded by grants PI20-00335 (Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Spain supported by FEDER funds). MM-M was funded by grants PI18/00367 (Fondo de Investigaciones Sanitarias, ISCIII, Spain, supported by FEDER funds), AC19/00006 (Projects of International Programs, ISCIII, Spain, supported by FEDER funds), Cohorte FPI CIBERES-ISCIII, Barcelona Respiratory Network-Fundation Ramon Pla Armengol, Spanish Society of Respiratory (SEPAR), and Catalan Society of Respiratory (SOCAP-FUCAP). CF was funded by Ministerio de Ciencia e InnovaciĂłn (grant RTC-2017-6471-1; AEI/FEDER, UE), and by Cabildo Insular de Tenerife (CGIEU0000219140)
A framework for models of movement in geographic space
This article concerns the theoretical foundations of movement informatics. We discuss general frameworks in which models of spatial movement may be developed. In particular, the article considers the objectâfield and LagrangianâEulerian dichotomies, and the SNAP/SPAN ontologies of the dynamic world, and classifies the variety of informatic structures according to these frameworks. A major challenge is transitioning between paradigms. Usually data is captured with respect to one paradigm but can usefully be represented in another. We discuss this process in formal terms and then describe experiments that we performed to show feasibility. It emerges that observational granularity plays a crucial role in these transitions
"Go Back to the Land!" Negotiating Space, Framing Governmentality in Lambwe Valley, Kenya 1954-75
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