1,842 research outputs found
GESTIÓN DE LA TECNOLOGÍA: UNA EXPLORACIÓN DEL USO DE LAS REDES SOCIALES EN LOS GOBIERNOS ESTATALES DE MÉXICO
The influence of technology in public administration has marked a new stage for the governments of the World. The strategy, known as e-Government, has to varying degrees impacted the way public offices are organized, the relationship with the citizens and the structure of public administration at its different levels. However, this impact has not been sufficiently measured and there is little evidence in this regard. One of the most innovative elements in this government transformation is social networking. The impact of these platforms –such as Twitter and Facebook– in communication and government operations has shifted the way in which information and communication technologies have changed the citizen-government relationship. The aim of this paper is to understand to what extent both these platforms are used in the 32 Mexican state portals and see how this use has evolved between 2010 and 2011.La influencia de la tecnología en la administración pública ha marcado una nueva etapa para los gobiernos del mundo. La estrategia conocida como Gobierno Electrónico, ha impactado en distinta medida la forma de organizar las oficinas públicas, la relación con los ciudadanos y la estructura de la administración pública en sus distintos niveles. Sin embargo, este impacto no se ha medido suficientemente y existe escasa evidencia a este respecto. Uno de los elementos más innovadores en esta transformación del gobierno es el uso de redes sociales. El impacto de estas plataformas – como Twitter y Facebook– en la comunicación y operaciones del gobierno ha dado un giro en la manera en que las Tecnologías de Información y Comunicación han modificado la relación ciudadano-gobierno. El objetivo de este artículo es entender qué tanto se utilizan dichas plataformas en los 32 portales estatales mexicanos y observar de qué forma ha evolucionado su uso entre 2010 y 2011
Spread of the invasive alga Caulerpa racemosa var. cylindracea (Caulerpales, Chlorophyta) along the Mediterranean Coast of the Murcia region (SE Spain)
The aim of this paper was to document the appearance and spread of the green alga Caulerpa racemosa along the coast of Murcia in south–eastern Spain. It was found for the first time in the area in 2005 and over the next two years the number of new sightings increased almost exponentially. In the period 2005–2007 the total surface area colonised by the alga in the region was estimated to be at least 265 ha. Benthic assemblages colonised by the alga were rocky bottoms with photophilic algae, dead P. oceanica rhizomes, infralittoral and circalittoral soft bottoms and maerl beds. No penetration of the alga was observed in P. oceanica meadows, except in one locality. Biometric analysis indicated high vegetative development in the established colonies in comparison to those described in other Mediterranean areas. Rapid spreading dynamics observed in the Murcia region is a potential threat for native benthic communities.
Key words: Biological invasions, Caulerpa racemosa var. cylindracea, Colonised surface area, Distribution, Mediterranean Sea, Spain.En el presente trabajo se documenta la aparición y dispersión del alga verde Caulerpa racemosa a lo largo de la costa de Murcia, región situada en el sureste español. El alga fue detectada por primera vez en el año 2005 y durante los dos años consecutivos se observó un crecimiento casi exponencial en el número de áreas colonizadas. La superficie total colonizada por el alga en Murcia durante el periodo 2005–2007 ha sido estimada en 265 ha., siendo las comunidades bentónicas afectadas algas fotófilas sobre sustrato rocoso, "mata muerta" de P. oceanica, fondos blandos infralitorales y circalitorales y fondos con comunidades de maërl. La presencia del alga dentro de praderas de P. oceanica solamente fue detectada en una localidad. Los estudios biométricos realizados muestran un elevado desarrollo vegetativo de las poblaciones de C. racemosa en Murcia en comparación con colonias de otras áreas del Mediterráneo, siendo esta rápida dinámica de expansión una amenaza potencial para las comunidades bentonicas nativas.
Palabras clave: Invasiones biológicas, Caulerpa racemosa var. cylindracea, Superficie colonizada, Mar
Mediterraneo, España.The aim of this paper was to document the appearance and spread of the green alga Caulerpa racemosa along the coast of Murcia in south–eastern Spain. It was found for the first time in the area in 2005 and over the next two years the number of new sightings increased almost exponentially. In the period 2005–2007 the total surface area colonised by the alga in the region was estimated to be at least 265 ha. Benthic assemblages colonised by the alga were rocky bottoms with photophilic algae, dead P. oceanica rhizomes, infralittoral and circalittoral soft bottoms and maerl beds. No penetration of the alga was observed in P. oceanica meadows, except in one locality. Biometric analysis indicated high vegetative development in the established colonies in comparison to those described in other Mediterranean areas. Rapid spreading dynamics observed in the Murcia region is a potential threat for native benthic communities.
Key words: Biological invasions, Caulerpa racemosa var. cylindracea, Colonised surface area, Distribution, Mediterranean Sea, Spain
Maternal imprinting on cognition markers of wild type and transgenic Alzheimer's disease model mice.
The risk of suffering from Alzheimer's disease (AD) is higher in individuals from AD-affected mothers. The purpose of this investigation was to study whether maternal transmission might produce AD-related alterations in progenies of mice that do not have any genotypic alteration. We used cognitively-intact mothers harbouring in heterozygosity the transgene for overexpressing the Swedish double mutant version of the human amyloid precursor protein (hAβPPswe). The phenotype of the offspring with or without the transgene resulting from crossing young Tg2576 females with wild-type males were compared with those of the offspring resulting from crossing wild-type females with Tg2576 males. The hAβPPswe-bearing offspring from Tg2576 mothers showed an aggravated AD-like phenotype. Remarkably, cognitive, immunohistochemical and some biochemical features displayed by Tg2576 heterozygous mice were also found in wild-type animals generated from Tg2576 females. This suggests the existence of a maternal imprinting in the wild-type offspring that confers a greater facility to launch an AD-like neurodegenerative cascade. Such progeny, lacking any mutant amyloid precursor protein, constitutes a novel model to study maternal transmission of AD and, even more important, to discover early risk markers that predispose to the development of AD
Maturity and Evolution of E-Government Portals in Central America: A Three-year Assessment 2011-2013
ABSTRACT The construction, deployment and delivery of Internet citizen portals does not necessarily follow the same process in developed and developing countries and there is not enough research about less developed nations. These government-wide websites could potentially become the gateways for citizen participation and collaboration with government. This paper applies a multidimensional evaluation model to the national citizen portals of Central American countries in three consecutive years (2011)(2012)(2013) and compares its results with demographic and economic data in order to provide some of the necessary knowledge about this phenomenon. Using a model that was first used in 2005 for evaluating Mexican state portals, a ranking is generated for the 26 Central America countries
Maternal imprinting on cognition markers of wild type and transgenic Alzheimer's disease model mice
The risk of suffering from Alzheimer’s disease (AD) is higher in individuals from AD-affected mothers. The purpose of this investigation was to study whether maternal transmission might produce AD-related alterations in progenies of mice that do not have any genotypic alteration. We used cognitively-intact mothers harbouring in heterozygosity the transgene for overexpressing the Swedish double mutant version of the human amyloid precursor protein (hAβPPswe). The phenotype of the offspring with or without the transgene resulting from crossing young Tg2576 females with wild-type males were compared with those of the offspring resulting from crossing wild-type females with Tg2576 males. The hAβPPswe-bearing offspring from Tg2576 mothers showed an aggravated AD-like phenotype. Remarkably, cognitive, immunohistochemical and some biochemical features displayed by Tg2576 heterozygous mice were also found in wild-type animals generated from Tg2576 females. This suggests the existence of a maternal imprinting in the wild-type offspring that confers a greater facility to launch an AD-like neurodegenerative cascade. Such progeny, lacking any mutant amyloid precursor protein, constitutes a novel model to study maternal transmission of AD and, even more important, to discover early risk markers that predispose to the development of AD
Nitrogen uptake and internal recycling in Zostera marina exposed to oyster farming: eelgrass potential as a natural biofilter
Oyster farming in estuaries and coastal lagoons frequently overlaps with the distribution of seagrass meadows, yet there are few studies on how this aquaculture practice affects seagrass physiology. We compared in situ nitrogen uptake and the productivity of Zostera marina shoots growing near off-bottom longlines and at a site not affected by oyster farming in San Quintin Bay, a coastal lagoon in Baja California, Mexico. We used benthic chambers to measure leaf NH4 (+) uptake capacities by pulse labeling with (NH4)-N-15 (+) and plant photosynthesis and respiration. The internal N-15 resorption/recycling was measured in shoots 2 weeks after incubations. The natural isotopic composition of eelgrass tissues and vegetative descriptors were also examined. Plants growing at the oyster farming site showed a higher leaf NH4 (+) uptake rate (33.1 mmol NH4 (+) m(-2) day(-1)) relative to those not exposed to oyster cultures (25.6 mmol NH4 (+) m(-2) day(-1)). We calculated that an eelgrass meadow of 15-16 ha (which represents only about 3-4 % of the subtidal eelgrass meadow cover in the western arm of the lagoon) can potentially incorporate the total amount of NH4 (+) excreted by oysters (similar to 5.2 x 10(6) mmol NH4 (+) day(-1)). This highlights the potential of eelgrass to act as a natural biofilter for the NH4 (+) produced by oyster farming. Shoots exposed to oysters were more efficient in re-utilizing the internal N-15 into the growth of new leaf tissues or to translocate it to belowground tissues. Photosynthetic rates were greater in shoots exposed to oysters, which is consistent with higher NH4 (+) uptake and less negative delta C-13 values. Vegetative production (shoot size, leaf growth) was also higher in these shoots. Aboveground/belowground biomass ratio was lower in eelgrass beds not directly influenced by oyster farms, likely related to the higher investment in belowground biomass to incorporate sedimentary nutrients
The modulation of leaf metabolism plays a role in salt tolerance of Cymodocea nodosa exposed to hypersaline stress in mesocosms
Applying proteomics, we tested the physiological responses of the euryhaline seagrass
Cymodocea nodosa to deliberate manipulation of salinity in a mesocosm system.
Plants were subjected to a chronic hypersaline condition (43 psu) to compare protein
expression and plant photochemistry responses after 15 and 30 days of exposure
with those of plants cultured under normal/ambient saline conditions (37 psu). Results
showed a general decline in the expression level of leaf proteins in hypersaline stressed
plants, with more intense reductions after long-lasting exposure. Specifically, the
carbon-fixing enzyme RuBisCo displayed a lower accumulation level in stressed plants
relative to controls. In contrast, the key enzymes involved in the regulation of glycolysis,
cytosolic glyceraldehyde-3-phosphate dehydrogenase, enolase 2 and triose-phosphate
isomerase, showed significantly higher accumulation levels. These responses suggested
a shift in carbon metabolism in stressed plants. Hypersaline stress also induced a
significant alteration of the photosynthetic physiology of C. nodosa by means of a downregulation
in structural proteins and enzymes of both PSII and PSI. However we found
an over-expression of the cytochrome b559 alpha subunit of the PSII initial complex,
which is a receptor for the PSII core proteins involved in biogenesis or repair processes
and therefore potentially involved in the absence of effects at the photochemical level
of stressed plants. As expected hypersalinity also affects vacuolar metabolism by
increasing the leaf cell turgor pressure and enhancing the up-take of Na+ by overaccumulating
the tonoplast specific intrinsic protein pyrophosphate-energized inorganic
pyrophosphatase (H(+)-PPase) coupled to the Na+/H+-antiporter. The modulation of
carbon metabolism and the enhancement of vacuole capacity in Na+ sequestration and
osmolarity changes are discussed in relation to salt tolerance of C. nodosa.Postprin
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
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Extensive migration of young neurons into the infant human frontal lobe.
The first few months after birth, when a child begins to interact with the environment, are critical to human brain development. The human frontal lobe is important for social behavior and executive function; it has increased in size and complexity relative to other species, but the processes that have contributed to this expansion are unknown. Our studies of postmortem infant human brains revealed a collection of neurons that migrate and integrate widely into the frontal lobe during infancy. Chains of young neurons move tangentially close to the walls of the lateral ventricles and along blood vessels. These cells then individually disperse long distances to reach cortical tissue, where they differentiate and contribute to inhibitory circuits. Late-arriving interneurons could contribute to developmental plasticity, and the disruption of their postnatal migration or differentiation may underlie neurodevelopmental disorders
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