402 research outputs found
Espacios verdes urbanos y diversidad vegetal a diferentes escalas espacio-temporales: el ejemplo de Beijing, China
Beijing, the capital city of China, is one of the largest and most rapidly-urbanizing cities in the world. In this work, we present the main results of one decade’s research on urban vegetation and plant diversity changes in different urban structural units. Urban vegetation/plant diversity has been studied at two different levels: at the landscape level (greening percentage, fragmentation degree) and at the plant species level (structure, composition, and origin). Finally, concerns with the ability to study Beijing’s plant urban ecology are discussed.Pekín, la capital de China, es una de las urbes más pobladas y a la vez con una de las tasas de expansión urbana más rápidas del mundo. En el presente trabajo, se presentan los principales resultados tras una década de estudio de los cambios en la vegetación y diversidad vegetal urbana a lo largo de las diferentes unidades estructurales urbanas. La vegetación y la diversidad vegetal urbana se han estudiado a dos niveles: a nivel de paisaje (porcentaje de zonas verdes, grado de fragmentación) y a nivel de especie (estructura, composición y origen). En último lugar se discuten algunos aspectos relacionados con la metodología de estudio de la ecología urbana en Pekín
Crassula ovata, una nueva especie alóctona para China continental
Crassula ovata, the jade plant, is reported for the first time from mainland China. Two small populations have been discovered in the downtown of the city of Chengdu (Sichuan Province, western China).Se reporta por primera vez la presencia de Crassula ovata, o planta de jade, en China continental. Se han descubierto dos pequeñas poblaciones en el centro de la ciudad de Chengdu (provincia de Sichuan, oeste de China)
Functional magnetic resonance imaging evaluation of pain central sensitization phenomena in subjects with knee osteoarthritis
Bovine brain 6-phosphofructo-2-kinase/fructose 2,6-bisphosphate: evidence for a neural-specific isozyme
Bovine brain 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase was purified to homogeneity and characterized. This bifunctional enzyme is a homodimer with a subunit molecular weight of 120,000, which is twice that of all other known bifunctional enzyme isozymes. The kinase/bisphosphatase activity ratio was 3.0. The Km values for fructose 6-phosphate and ATP of the 6-phosphofructo-2-kinase were 27 and 55 microM, respectively. The Km for fructose 2,6-bisphosphate and the Ki for fructose 6-phosphate for the bisphosphatase were 70 and 20 microM, respectively. Physiologic concentrations of citrate had reciprocal effects on the enzyme's activities, i.e. inhibiting the kinase (Ki of 35 microM) and activating the bisphosphatase (Ka of 16 microM). Phosphorylation of the brain enzyme was catalyzed by the cyclic AMP-dependent protein kinase with a stoichiometry of 0.9 mol of phosphate/mol of subunit and at a rate similar to that seen with the liver isozyme. In contrast to the liver isozyme, the kinetic properties of the brain enzyme were unaffected by cyclic AMP-dependent protein kinase phosphorylation, and also was not a substrate for protein kinase C. The brain isozyme formed a labeled phosphoenzyme intermediate and cross-reacted with antibodies raised against the liver isozyme. However, the NH2-terminal amino acid sequence of a peptide generated by cyanogen bromide cleavage of the enzyme had no identity with any known bifunctional enzyme sequences. These results indicate that a novel isozyme, which is related to other 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isozymes, is expressed specifically in neural tissues
Notas sobre las especies de Kalanchoe (Crassulaceae) ocasionales y naturalizadas en Cuba
Many species of the genus Kalanchoe are widely cultivated due to their ornamental value. This, together with the high capacity of many species to be naturalized has caused some of them to grow nowadays in geographical areas distant from their natural ranges. During the last 65 years the number of species of Kalanchoe reported to Cuba has increased from two to five, according to recent publications. Apparently the lack of a current work gathering the naturalized species of this genus in Cuba and providing keys for their identification has led to discrepancies on the names cited in these publications. The present study is aimed to define the number of species of Kalanchoe that have been naturalized in Cuba, and to offer a key for their identification, descriptions and information on the localities where they have been found. It is estimated that six taxa of this genus grow spontaneously in Cuba. Three taxa are new for the flora of Cuba; one of them, K. laetivirens, is reported for the first time out of its native range. Images and maps are shown that allow a better understanding of the results.Muchas especies del género Kalanchoe se cultivan ampliamente por su valor ornamental, hecho que junto a la alta capacidad de muchas de ellas a naturalizarse ha causado que algunas crezcan en zonas geográficas distantes de sus áreas de distribución natural. En los últimos 65 años el número de especies de Kalanchoe reportadas para Cuba ha ascendido de dos a cinco, según publicaciones recientes. La falta de un trabajo actualizado que recoja las especies naturalizadas de este género en Cuba y que aporte unas claves para su correcta identificación ha conducido a la existencia de discrepancias en cuanto a algunos de los nombres citados en estas publicaciones. A la vista de dichos precedentes creímos oportuno realizar la presente investigación que tuvo como objetivos definir el número real de especies de Kalanchoe que crecen de manera silvestre en Cuba, ofrecer una clave para su identificación, así como descripciones e información sobre las localidades donde han sido encontradas. Se estima que en Cuba crecen espontáneamente seis taxones de este género, de los que tres se reportan por primera vez, uno de los cuales, K. laetivirens, también es novedad mundial. Aportamos también imágenes y mapas que permiten una mejor comprensión de los resultados
Ecos del XIX International Botanical Congress
Del 23 al 29 de juliol d’enguany va tenir lloc a Shenzhen (província de Guangdong, Xina) el XIX
International Botanical Congress (IBC), el principal simposi del món dedicat a la botànica, i que
se celebra cada sis anys. L’IBC va estar organitzat conjuntament per la Societat Botànica de la Xina
i el govern de la Municipalitat de Shenzhen. Una setmana abans del congrés, del 17 al 21 de juliol, va
tenir lloc la reunió de la Secció de Nomenclatura de l’IBC a la Ciutat Universitària de Shenzhen, amb
l’objectiu principal de revisar el codi internacional de nomenclatura.Peer reviewe
Impaired mitochondrial oxidative phosphorylation in the peroxisomal disease X-linked adrenoleukodystrophy
This is a pre-copyedited, author-produced PDF of an article accepted for publication in Human Molecular Genetics following peer review. The version of record Human Molecular Genetics 22.16 (2013): 3296-3305 is available online at http://hmg.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=23604518X-linked adrenoleukodystrophy (X-ALD) is an inherited metabolic disorder of the nervous system characterized by axonopathy in spinal cords and/or cerebral demyelination, adrenal insufficiency and accumulation of very long-chain fatty acids (VLCFAs) in plasma and tissues. The disease is caused by malfunction of the ABCD1 gene, which encodes a peroxisomal transporter of VLCFAs or VLCFA-CoA. In the mouse, Abcd1 loss causes late onset axonal degeneration in the spinal cord, associated with locomotor disability resembling the most common phenotype in patients, adrenomyeloneuropathy. We have formerly shown that an excess of the VLCFA C26:0 induces oxidative damage, which underlies the axonal degeneration exhibited by the Abcd1(-) mice. In the present study, we sought to investigate the noxious effects of C26:0 on mitochondria function. Our data indicate that in X-ALD patients' fibroblasts, excess of C26:0 generates mtDNA oxidation and specifically impairs oxidative phosphorylation (OXPHOS) triggering mitochondrial ROS production from electron transport chain complexes. This correlates with impaired complex V phosphorylative activity, as visualized by high-resolution respirometry on spinal cord slices of Abcd1(-) mice. Further, we identified a marked oxidation of key OXPHOS system subunits in Abcd1(-) mouse spinal cords at presymptomatic stages. Altogether, our results illustrate some of the mechanistic intricacies by which the excess of a fatty acid targeted to peroxisomes activates a deleterious process of oxidative damage to mitochondria, leading to a multifaceted dysfunction of this organelle. These findings may be of relevance for patient management while unveiling novel therapeutic targets for X-ALDThis study was supported by grants from the European Commission (FP7-241622), the European Leukodystrophy Association (ELA2009-036C5; ELA2008-040C4), the Spanish Institute for Health Carlos III (FIS PI080991 and FIS PI11/01043), the Autonomous Government of Catalonia (2009SGR85) to A.P. and the Spanish Institute for Health Carlos III (Miguel Servet program CP11/00080) to S.F. The CIBER on Rare Diseases (CIBERER) is an initiative of the ISCIII. The study was developed under the COST action BM0604 (to A.P.). J.L.-E. was a fellow of the Department of Education, Universities and Research of the Basque Country Government (BFI07.126). S.F. was a fellow of the European Leukodystrophy Association (ELA 2010-020F1). The studies conducted at the Department of Experimental Medicine were supported in part by R&D grants from the Spanish Ministry of Science and Innovation (BFU2009-11879/BFI), the Spanish Ministry of Health (PI11/1532), the Autonomous Government of Catalonia (2009SGR735), the ‘La Caixa’ Foundation and COST B35 Action of the European Union. D.C. is a fellow from the Spanish Ministry of Health (FI08-00707). The studies conducted at the Department of Biochemistry and Molecular Biology, University of Barcelona, were supported by grants SAF2008-01896 and SAF2011-23636 from the Spanish Ministry of Science and Innovatio
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