1,161 research outputs found
Un SIG corporativo en el IGN para la gestión integrada, publicación y análisis de datos geográficos
El Instituto Geográfico Nacional inició en el año 2003 los estudios previos necesarios para un proyecto ambicioso y a la vez esencial para el cumplimiento de sus responsabilidades básicas, la implantación de un Sistema de Información Geográfica (SIG) corporativo que atendiera a tres finalidades fundamentales: a) la gestión integrada de los datos geográficos y cartográficos que produce, en forma de Bases Cartográficas Numéricas (BCN) y en forma de mapas, respectivamente, incluyendo su actualización coordinada; b) la publicación de tales datos en papel, en soporte digital y de manera electrónica (Infraestructura de Datos Espaciales (IDE)); c) el análisis y consulta desde clientes ligeros y pesados para todo tipo de aplicaciones. Por lo tanto, el sistema constituye a la vez el soporte básico para la publicación de cartografía y para la consulta de los datos geográficos desde clientes a través de la Web,mediante el desarrollo de servicios de análisis
Evaluation of vineyard growth under four irrigation regimes using vegetation and soil on-the-go sensors
Precision agriculture is a useful tool to assess plant growth and development in vineyards. The present
study focused on spatial and temporal analysis of vegetation growth variability, in four irrigation treatments with
four replicates. The research was carried out in a vineyard located in the southwest of Spain during the 2012
and 2013 growing seasons. Two multispectral sensors mounted on an all-terrain vehicle (ATV) were used in
the different growing seasons/stages in order to calculate the vineyard normalized difference vegetation index
(NDVI). Soil apparent electrical conductivity (ECa) was also measured up to 0.8m soil depth using an on-the-go
geophysical sensor. All measured data were analysed by means of principal component analysis (PCA). The
spatial and temporal NDVI and ECa variations showed relevant differences between irrigation treatments and
climatological conditions
Scalar and vector Slepian functions, spherical signal estimation and spectral analysis
It is a well-known fact that mathematical functions that are timelimited (or
spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the
finite precision of measurement and computation unavoidably bandlimits our
observation and modeling scientific data, and we often only have access to, or
are only interested in, a study area that is temporally or spatially bounded.
In the geosciences we may be interested in spectrally modeling a time series
defined only on a certain interval, or we may want to characterize a specific
geographical area observed using an effectively bandlimited measurement device.
It is clear that analyzing and representing scientific data of this kind will
be facilitated if a basis of functions can be found that are "spatiospectrally"
concentrated, i.e. "localized" in both domains at the same time. Here, we give
a theoretical overview of one particular approach to this "concentration"
problem, as originally proposed for time series by Slepian and coworkers, in
the 1960s. We show how this framework leads to practical algorithms and
statistically performant methods for the analysis of signals and their power
spectra in one and two dimensions, and, particularly for applications in the
geosciences, for scalar and vectorial signals defined on the surface of a unit
sphere.Comment: Submitted to the 2nd Edition of the Handbook of Geomathematics,
edited by Willi Freeden, Zuhair M. Nashed and Thomas Sonar, and to be
published by Springer Verlag. This is a slightly modified but expanded
version of the paper arxiv:0909.5368 that appeared in the 1st Edition of the
Handbook, when it was called: Slepian functions and their use in signal
estimation and spectral analysi
Altering crystal growth and annealing in ice-templated scaffolds.
The potential applications of ice-templating porous materials are constantly expanding, especially as scaffolds for tissue engineering. Ice-templating, a process utilizing ice nucleation and growth within an aqueous solution, consists of a cooling stage (before ice nucleation) and a freezing stage (during ice formation). While heat release during cooling can change scaffold isotropy, the freezing stage, where ice crystals grow and anneal, determines the final size of scaffold features. To investigate the path of heat flow within collagen slurries during solidification, a series of ice-templating molds were designed with varying the contact area with the heat sink, in the form of the freeze drier shelf. Contact with the heat sink was found to be critical in determining the efficiency of the release of latent heat within the perspex molds. Isotropic collagen scaffolds were produced with pores which ranged from 90 μm up to 180 μm as the contact area decreased. In addition, low-temperature ice annealing was observed within the structures. After 20 h at -30 °C, conditions which mimic storage prior to lyophilization, scaffold architecture was observed to coarsen significantly. In future, ice-templating molds should consider not only heat conduction during the cooling phase of solidification, but the effects of heat flow during ice growth and annealing.The authors gratefully acknowledge the financial support of the Gates Cambridge Trust, the Newton Trust, and ERC Advanced Grant 320598 3D-E. A.H. held a Daphne Jackson Fellowship funded by the University of Cambridge.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10853-015-9343-
Salt Reduction Initiatives around the World – A Systematic Review of Progress towards the Global Target
Objective
To quantify progress with the initiation of salt reduction strategies around the world in the context of the global target to reduce population salt intake by 30% by 2025.
Methods
A systematic review of the published and grey literature was supplemented by questionnaires sent to country program leaders. Core characteristics of strategies were extracted and categorised according to a pre-defined framework.
Results
A total of 75 countries now have a national salt reduction strategy, more than double the number reported in a similar review done in 2010. The majority of programs are multifaceted and include industry engagement to reformulate products (n = 61), establishment of sodium content targets for foods (39), consumer education (71), front-of-pack labelling schemes (31), taxation on high-salt foods (3) and interventions in public institutions (54). Legislative action related to salt reduction such as mandatory targets, front of pack labelling, food procurement policies and taxation have been implemented in 33 countries. 12 countries have reported reductions in population salt intake, 19 reduced salt content in foods and 6 improvements in consumer knowledge, attitudes or behaviours relating to salt.
Conclusion
The large and increasing number of countries with salt reduction strategies in place is encouraging although activity remains limited in low- and middle-income regions. The absence of a consistent approach to implementation highlights uncertainty about the elements most important to success. Rigorous evaluation of ongoing programs and initiation of salt reduction programs, particularly in low- and middle- income countries, will be vital to achieving the targeted 30% reduction in salt intake
Mice lacking endoglin in macrophages show an impaired immune response
24 p.-9 fig.-1 tab. Ojeda Fernández, Luisa et al.Endoglin is an auxiliary receptor for members of the TGF-β superfamily and plays an important role in the homeostasis of the vessel wall. Mutations in endoglin gene (ENG) or in the closely related TGF-β receptor type I ACVRL1/ALK1 are responsible for a rare dominant vascular dysplasia, the Hereditary Hemorrhagic Telangiectasia (HHT), or Rendu-OslerWeber syndrome. Endoglin is also expressed in human macrophages, but its role in macrophage function remains unknown. In this work, we show that endoglin expression is triggered during the monocyte-macrophage differentiation process, both in vitro and during the in vivo differentiation of blood monocytes recruited to foci of inflammation in wild-type C57BL/6 mice. To analyze the role of endoglin in macrophages in vivo, an endoglin myeloid lineage specific knock-out mouse line (Engfl/flLysMCre) was generated. These mice show a predisposition to develop spontaneous infections by opportunistic bacteria. Engfl/flLysMCre mice also display increased survival following LPS-induced peritonitis, suggesting a delayed immune response. Phagocytic activity is impaired in peritoneal macrophages, altering one of the main functions of macrophages which contributes to the initiation of the immune response. We also observed altered expression of TGF-β1 target genes in endoglin
deficient peritoneal macrophages. Overall, the altered immune activity of endoglin deficient macrophages could help to explain the higher rate of infectious diseases seen in HHT1 patients.This work was funded by: Ministerio de Economía y Competitividad of Spain (SAF2011-23475 to LMB; SAF2013-43421-R and SAF2010-
19222 to CB.Peer reviewe
Quality of life: international and domestic students studying medicine in New Zealand
International students form a significant proportion of students studying within universities in Western countries. The quality of life perceptions of international medical students in comparison with domestic medical students has not been well documented. There is some evidence to suggest that international medical students may have different educational and social experiences in relation to their domestic peers. This study investigates the levels of quality of life experienced by international and domestic students studying medicine. A total of 548 medical students completed the abbreviated version of the World Health Organization Quality of Life questionnaire. The focus of the analysis was to evaluate differences between international and domestic students in their early clinical years. The responses were analysed using multivariate analysis of variance methods. International medical students are experiencing lower social and environmental quality of life compared with domestic peers. International medical students in New Zealand have expressed quality of life concerns, which likely have an impact on their academic achievement, feelings of wellness, acculturation, and social adaptation. The findings reinforce the need for creating stronger social networks and accessible accommodation, as well as developing systems to ensure safety, peer mentorship and student support.published_or_final_versio
Urocortin protects chondrocytes from NO-induced apoptosis: a future therapy for osteoarthritis?
Osteoarthritis (OA) is characterized by a loss of joint mobility and pain resulting from progressive destruction and loss of articular cartilage secondary to chondrocyte death and/ or senescence. Certain stimuli including nitric oxide (NO) and the pro-inflammatory cytokine tumor necrosis factor α (TNF-α have been implicated in this chondrocyte death and the subsequent accelerated damage to cartilage. In this study, we demonstrate that a corticotrophin releasing factor (CRF) family peptide, urocortin (Ucn), is produced by a human chondrocyte cell line, C-20/A4, and acts both as an endogenous survival signal and as a cytoprotective agent reducing the induction of apoptosis by NO but not TNF-α when added exogenously. Furthermore, treatment with the NO donor S-nitroso-N-acetyl-D-L-penicillamine upregulates chondrocyte Ucn expression, whereas treatment with TNF-α does not. The chondroprotective effects of Ucn are abolished by both specific ligand depletion (with an anti-Ucn antibody) and by CRF receptor blockade with the pan-CRFR antagonist α-helical CRH(9-41). CRFR expression was confirmed by reverse transcription-PCR with subsequent amplicon sequence analysis and demonstrates that C-20/A4 cells express both CRFR1 and CRFR2, specifically CRFR1α and CRFR2β. Protein expression of these receptors was confirmed by western blotting. The presence of both Ucn and its receptors in these cells, coupled with the induction of Ucn by NO, suggests the existence of an endogenous autocrine/paracrine chondroprotective mechanism against stimuli inducing chondrocyte apoptosis via the intrinsic/mitochondrial pathway
Study of the chemotactic response of multicellular spheroids in a microfluidic device
YesWe report the first application of a microfluidic device to observe chemotactic migration in
multicellular spheroids. A microfluidic device was designed comprising a central microchamber
and two lateral channels through which reagents can be introduced. Multicellular
spheroids were embedded in collagen and introduced to the microchamber. A gradient of
fetal bovine serum (FBS) was established across the central chamber by addition of growth
media containing serum into one of the lateral channels. We observe that spheroids of oral
squamous carcinoma cells OSC–19 invade collectively in the direction of the gradient of
FBS. This invasion is more directional and aggressive than that observed for individual cells
in the same experimental setup. In contrast to spheroids of OSC–19, U87-MG multicellular
spheroids migrate as individual cells. A study of the exposure of spheroids to the chemoattractant
shows that the rate of diffusion into the spheroid is slow and thus, the chemoattractant
wave engulfs the spheroid before diffusing through it.This work has been supported by National Research Program of Spain (DPI2011-28262-c04-01) and by the project "MICROANGIOTHECAN" (CIBERBBN, IMIBIC and SEOM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Stem cell function and stress response are controlled by protein synthesis.
Whether protein synthesis and cellular stress response pathways interact to control stem cell function is currently unknown. Here we show that mouse skin stem cells synthesize less protein than their immediate progenitors in vivo, even when forced to proliferate. Our analyses reveal that activation of stress response pathways drives both a global reduction of protein synthesis and altered translational programmes that together promote stem cell functions and tumorigenesis. Mechanistically, we show that inhibition of post-transcriptional cytosine-5 methylation locks tumour-initiating cells in this distinct translational inhibition programme. Paradoxically, this inhibition renders stem cells hypersensitive to cytotoxic stress, as tumour regeneration after treatment with 5-fluorouracil is blocked. Thus, stem cells must revoke translation inhibition pathways to regenerate a tissue or tumour.This work was funded by Cancer Research UK (CR-UK), Worldwide Cancer Research, the Medical Research Council (MRC), the European Research Council (ERC), and EMBO. Research in Michaela Frye's laboratory is supported by a core support grant from the Wellcome Trust and MRC to the Wellcome Trust-Medical Research Cambridge Stem Cell Institute.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nature1828
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