539 research outputs found

    Assembly and disassembly of the Golgi Complex: two prodesses arranged in a cis to trans direction

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    We have studied the disassembly and assembly of two morphologically and functionally distinct parts of the Golgi complex, the cis/middle and trans cisterna/trans network compartments. For this purpose we have followed the redistribution of three cis/middle- (GMPc-1, GMPc-2, MG 160) and two trans- (GMPt-1 and GMPt-2) Golgi membrane proteins during and after treatment of normal rat kidney (NRK) cells with brefeldin A (BFA). BFA induced complete disassembly of the cis/middle- and trans-Golgi complex and translocation of GMPc and GMPt to the ER. Cells treated for short times (3 min) with BFA showed extensive disorganization of both cis/middle- and trans-Golgi complexes. However, complete disorganization of the trans part required much longer incubations with the drug. Upon removal of BFA the Golgi complex was reassembled by a process consisting of three steps: (a) exist of cis/middle proteins from the ER and their accumulation into vesicular structures scattered throughout the cytoplasm; (b) gradual relocation and accumulation of the trans proteins in the vesicles containing the cis/middle proteins; and (c) assembly of the cisternae, and reconstruction of the Golgi complex within an area located in the vicinity of the centrosome from which the ER was excluded. Reconstruction of the cis/middle-Golgi complex occurred under temperature conditions inhibitory of the reorganization of the trans-Golgi complex, and was dependent on microtubules. Reconstruction of the trans-Golgi complex, disrupted with nocodazole after selective fusion of the cis/middle-Golgi complex with the ER, occurred after the release of cis/middle-Golgi proteins from the ER and the assembly of the cis/middle cisternae

    Ground-Based Ultraviolet-Radiation Measurements during Springtime in the Southern Hemisphere

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    We report the first measurements obtained by a network of UV-B detectors established through Argentina and Chile, at locations covering latitudes extending from 53°S to 18° S. Evidence that UVB increases are detected at these latitudes during the Austral spring 1993 is presented

    Ground-based ultraviolet-radiation measurements during springtime in the Southern hemisphere

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    We report the first measurements obtained by a network of UV-B detectors established through Argentina and Chile, at locations covering latitudes extending from 53°S to 18° S. Evidence that UVB increases are detected at these latitudes during the Austral spring 1993 is presented. The destruction of the stratospheric ozone layer is generally considered one of the most serious environmental problems. It has been recently published that during October 1998 the ozone hole has been the deepest ever recorded. Reduction of the stratospheric ozone layer was un ambiguously detected about two decades ago in the Antarctic continent. Since then it has been systematically monitored by different means (satellite, balloon soundings and ground station observations. One of the most serious content reduction is the increase of biologically effective ultraviolet doses, particularly the so-called ultraviolet B radiation (280-320 nm) received at the Earth surface, with multiple possible hazards for living species. Despite these consequences, ground stations to check the UV Sun radiation are not very numerous, particularly outside the circumpolar area in the Southern Hemisphere. With the aim of studying whether the ozone depletion over the Antarctic area has extended further, and whether the possibility that UV radiation increase may begin to affect inhabited regions, a network of UVB detectors has been established through Argentina and Chile, at locations covering latitudes extending from 53°S to 18° S. Here we report the first measurements obtained by this network providing evidence that UVB increases are detected at these latitudes during the last Austral spring.Facultad de Ciencias Exacta

    Improving stem quality assessment based on national forest inventory data: an approach applied to Spanish forests

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    20 Pág.Key message: This paper proposes a methodology that could be considered as a base for a harmonized protocol for stem-quality reporting in Europe while conducting National Forest Inventories, in order to cost-efficiently obtain a visual wood quality proxy. The importance of the variables selected, the limitations identified, and some improvements to the methodology are suggested. Forest areas with better wood quality, which in turn it would be useful for breeding programs, can be easily detected. Context: The establishment of harmonized standards or indicators that allow us to determine the quality of the wood present in a forest prior to its exploitation has long been demanded by the European forestry sector, although agreed methodologies for the evaluation of wood quality in standing trees, which is one of the sector’s most urgent requirements, have not, as yet, been implemented. Aims: To develop a protocol that visually characterizes wood quality on standing trees in a cost-effective way for the National Forest Inventory (NFI). After some improvements, it can be considered as a base for a European harmonized protocol. Methods: In this article, we analyze the implementation, in the NFI, of a visual wood-quality assessment methodology in forests of Central Spain based on the different European standards as well as on research papers addressing this issue. Results: The silvicultural practices employed are of the utmost importance to obtain the best wood quality, regardless of the species. Several areas with higher wood quality were identified as well as areas most affected by specific pests in the studied region. The impact of the variables measured (e.g., branchiness, crookedness, maximum branch diameter) is discussed. Conclusion: It is feasible to estimate a proxy for wood quality on standing trees in the NFI. Furthermore, after studying the inventory data provided, several enhancements are proposed, not only to improve wood-quality estimates but also to optimize fieldwork costs. Harmonizing NFIs to assess and map European standing wood quality can be achieved.This work was supported by the Spanish Ministry of Agriculture, Fishing and Food (Encomienda de Gestión. EG17-042 “Soporte científico a la generación de información Forestal”).Peer reviewe

    Paralytic Toxin Producing Dinoflagellates in Latin America: Ecology and Physiology

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    In this review we summarize the current state of knowledge regarding taxonomy, bloom dynamics, toxicity, autoecology, and trophic interactions, of saxitoxin producing dinoflagellates in this region. The dinoflagellates Gymnodinium catenatum, Pyrodinium bahamense and several species of Alexandrium are saxitoxin producers, and have been responsible of paralytic shellfish poisoning in different regions of Latin America, causing intoxications and important fisheries losses. The species distribution differ; most harmful algal blooms of G. catenatum are from the northern region, however this species has also been reported in central and southern regions. Blooms of P. bahamense are mostly reported in North and Central America, while blooms of Alexandrium species are more common in South America, however this genus is widely spread in Latin America. Species and regional differences are contrasted, with the aim to contribute to future guidelines for an international scientific approach for research and monitoring activities that are needed to increase our understanding of paralytic toxin producing dinoflagellates in this region

    Ground-based ultraviolet-radiation measurements during springtime in the Southern hemisphere

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    We report the first measurements obtained by a network of UV-B detectors established through Argentina and Chile, at locations covering latitudes extending from 53°S to 18° S. Evidence that UVB increases are detected at these latitudes during the Austral spring 1993 is presented. The destruction of the stratospheric ozone layer is generally considered one of the most serious environmental problems. It has been recently published that during October 1998 the ozone hole has been the deepest ever recorded. Reduction of the stratospheric ozone layer was un ambiguously detected about two decades ago in the Antarctic continent. Since then it has been systematically monitored by different means (satellite, balloon soundings and ground station observations. One of the most serious content reduction is the increase of biologically effective ultraviolet doses, particularly the so-called ultraviolet B radiation (280-320 nm) received at the Earth surface, with multiple possible hazards for living species. Despite these consequences, ground stations to check the UV Sun radiation are not very numerous, particularly outside the circumpolar area in the Southern Hemisphere. With the aim of studying whether the ozone depletion over the Antarctic area has extended further, and whether the possibility that UV radiation increase may begin to affect inhabited regions, a network of UVB detectors has been established through Argentina and Chile, at locations covering latitudes extending from 53°S to 18° S. Here we report the first measurements obtained by this network providing evidence that UVB increases are detected at these latitudes during the last Austral spring.Facultad de Ciencias Exacta

    Dendritic cells in cancer immunology and immunotherapy

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    Dendritic cells (DCs) are a diverse group of specialized antigen-presenting cells with key roles in the initiation and regulation of innate and adaptive immune responses. As such, there is currently much interest in modulating DC function to improve cancer immunotherapy. Many strategies have been developed to target DCs in cancer, such as the administration of antigens with immunomodulators that mobilize and activate endogenous DCs, as well as the generation of DC-based vaccines. A better understanding of the diversity and functions of DC subsets and of how these are shaped by the tumour microenvironment could lead to improved therapies for cancer. Here we will outline how different DC subsets influence immunity and tolerance in cancer settings and discuss the implications for both established cancer treatments and novel immunotherapy strategies.S.K.W. is supported by a European Molecular Biology Organization Long- Term Fellowship (grant ALTF 438– 2016) and a CNIC–International Postdoctoral Program Fellowship (grant 17230–2016). F.J.C. is the recipient of a PhD ‘La Caixa’ fellowship. Work in the D.S. laboratory is funded by the CNIC, by the European Research Council (ERC Consolidator Grant 2016 725091), by the European Commission (635122-PROCROP H2020), by the Ministerio de Ciencia, Innovación e Universidades (MCNU), Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (FEDER) (SAF2016-79040-R), by the Comunidad de Madrid (B2017/BMD-3733 Immunothercan- CM), by FIS- Instituto de Salud Carlos III, MCNU and FEDER (RD16/0015/0018-REEM), by Acteria Foundation, by Atresmedia (Constantes y Vitales prize) and by Fundació La Marató de TV3 (201723). The CNIC is supported by the Instituto de Salud Carlos III, the MCNU and the Pro CNIC Foundation, and is a Severo Ochoa Centre of Excellence (SEV-2015-0505).S

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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