584 research outputs found
Online news consumption and the gratification level of its users: a foundation for a media literacy action plan
News consumption methods are changing with more traditional media taking their back seat to personal, portable, and other connected devices. This instant access also leads to more news-fueling time for local, national, and international news. This study looked at online news consumption and five gratifications among two hundred and seventy-seven communication, and journalism university students in Metro Manila, Philippines. A quantitative method was used to confirm five motivations based on past research and to find new gratification. Results show that the respondents confirmed four uses and gratification of previous research (identify signaling, social relationship, escape, entertainment) and found one new gratification, "infotainment." Results also revealed that online news websites were statistically relevant. Significant relationships exist between respondents and demographics about online news consumption and demographics are statistically significant. Demographic information and online news consumption are relevant to communication and journalism students. However, the user’s level of uses and gratifications is a predictor of online news consumption. Only surveillance can predict the online news consumption of students. Also, this study finds that reading online news by students is often more motivated by amusement and pleasure infotainment as a form of dissemination of information. It was argued that online news consumption contributed to the existing body of literature with a specific audience of 18-year-olds. Infotainment is a dominant factor in online news consumption throughout the results and discussions
Anotação semântica de dados geoespaciais para a agricultura.
Dados geoespaciais são base para sistemas de decisão em vários domínios. Para serem usados esses dados precisam ser analisados e interpretados por especialistas. Essas interpretações geralmente não são armazenadas ou correspondem apenas a alguma informação textual e em linguagem própria, gravadas em arquivos técnicos. A ausência de soluções eficientes para armazená-las leva a problemas como retrabalho e dificuldades de compartilhamento de informação. Este trabalho apresenta uma solução para esse problema que baseia-se no uso de anotações semânticas, uma abordagem que promove um entendimento comum dos conceitos usados. Com a adoção de workflows científicos e também de um esquema de metadados e de ontologias bem conhecidos, foi especificado e parcialmente implementado um framework para anotação semântica de dados geoespaciais, focando na solução de problemas em agricultura.bitstream/item/32414/1/BolPesq25.pd
The Extended GMRT Radio Halo Survey I: New upper limits on radio halos and mini-halos
A fraction of galaxy clusters host diffuse radio sources called radio halos,
radio relics and mini-halos. We present the sample and first results from the
Extended GMRT Radio Halo Survey (EGRHS)- an extension of the GMRT Radio Halo
Survey (GRHS, Venturi et al. 2007, 2008). It is a systematic radio survey of
galaxy clusters selected from the REFLEX and eBCS X-ray catalogs . Analysis of
GMRT data at 610/ 235/ 325 MHz on 12 galaxy clusters are presented. We report
the detection of a newly discovered mini-halo in the cluster RXJ1532.9+3021 at
610 MHz. A small scale relic (~200 kpc) is suspected in the cluster Z348. We do
not detect cluster-scale diffuse emission in 11 clusters. Robust upper limits
on the detection of radio halo of size of 1 Mpc are determined. We also present
upper limits on the detections of mini-halos in a sub-sample of cool-core
clusters. The upper limits for radio halos and mini-halos are plotted in the
radio power- X-ray luminosity plane and the correlations are discussed. Diffuse
extended emission, not related to the target clusters, but detected as
by-products in the sensitive images of two of the cluster fields (A689 and
RXJ0439.0+0715) are reported. Based on the information about the presence of
radio halos (or upper limits), available on 48 clusters out of the total sample
of 67 clusters (EGRHS+GRHS), we find that ~23% of the clusters host radio
halos. The radio halo fraction rises to ~31%, when only the clusters with X-ray
luminosities >8x10^44 erg/s are considered. Mini-halos are found in ~50 % of
cool-core clusters. A qualitative examination of the X-ray images of the
clusters with no diffuse radio emission indicates that a majority of these
clusters do not show extreme dynamical disturbances and supports the idea that
mergers play an important role in the generation of radio halos/relics.Comment: 21 pages, 18 figures, 3 tables, accepted for publication in A&
Pure silica nanoparticles for liposome/lipase system encapsulation: Application in biodiesel production
In this work we report the synthesis of organic inorganic solid with spherical morphology where enzyme, as active compounds, is encapsulated. The organic phase of nanospheres is composed of l-phosphatidylcholine, as liposome, and lipase from Rhizomucor miehei, as enzyme. The organic phase is covered with porous inorganic silica shell that could stabilize the internal liposomal phase and, consequently, isolate and protect the bioactive molecules. The liposome and silica amount used during the immobilization procedure have been optimized in order to obtain active and stable heterogeneous biocatalyst. Hybrid-nanospheres containing the enzyme were used to catalyze the transesterification reaction of triolein with methanol to methyl esters, typical biodiesel mixture compounds. The encapsulated enzyme retains its activity after 5 reaction cycles. The total productivity of the best catalyst obtained is higher than that of the free enzyme.The authors, A.C. and U.D., thank the Spanish MICINN (Consolider Ingenio 2010-MULTICAT (CSD2009-00050) and MAT2011-29020-C02-01) for their financial support.Macario, A.; Verri, F.; Díaz Morales, UM.; Corma Canós, A.; Giordano, G. (2013). Pure silica nanoparticles for liposome/lipase system encapsulation: Application in biodiesel production. Catalysis Today. 204:148-155. doi:10.1016/j.cattod.2012.07.014S14815520
An elusive radio halo in the merging cluster Abell 781?
Deep radio observations of the galaxy cluster Abell 781 have been carried out
using the Giant Metrewave Radio Telescope at 325 MHz and have been compared to
previous 610 MHz observations and to archival VLA 1.4 GHz data. The radio
emission from the cluster is dominated by a diffuse source located at the
outskirts of the X-ray emission, which we tentatively classify as a radio
relic. We detected residual diffuse emission at the cluster centre at the level
of S(325 MHz)~15-20 mJy. Our analysis disagrees with Govoni et al. (2011), and
on the basis of simple spectral considerations we do not support their claim of
a radio halo with flux density of 20-30 mJy at 1.4 GHz. Abell 781, a massive
and merging cluster, is an intriguing case. Assuming that the residual emission
is indicative of the presence of a radio halo barely detectable at our
sensitivity level, it could be a very steep spectrum source.Comment: 5 pages, 4 figures, 1 table - Accepted for publication on Monthly
Notices of the Royal Astronomical Society Letter
Shock acceleration as origin of the radio relic in A521?
We present new high sensitivity observations of the radio relic in A521
carried out with the Giant Metrewave Radio Telescope at 327 MHz and with the
Very Large Array at 4.9 and 8.5 GHz. We imaged the relic at these frequencies
and carried out a detailed spectral analysis, based on the integrated radio
spectrum between 235 MHz and 4.9 GHz, and on the spectral index image in the
frequency range 327-610 MHz. To this aim we used the new GMRT observations and
other proprietary as well as archival data. We also searched for a possible
shock front co-located with the relic on a short archival Chandra X-ray
observation of the cluster. The integrated spectrum of the relic is consistent
with a single power law; the spectral index image shows a clear trend of
steepening going from the outer portion of the relic toward the cluster centre.
We discuss the origin of the source in the light of the theoretical models for
the formation of cluster radio relics. Our results on the spectral properties
of the relic are consistent with acceleration of relativistic electrons by a
shock in the intracluster medium. This scenario is further supported by our
finding of an X-ray surface brightness edge coincident with the outer border of
the radio relic. This edge is likely a shock front.Comment: 13 pages, 12 figures, accepted for publication in A&
The Extended GMRT Radio Halo Survey II: Further results and analysis of the full sample
The intra-cluster medium contains cosmic rays and magnetic fields that are
manifested through the large scale synchrotron sources, termed as radio halos,
relics and mini-halos. The Extended Giant Metrewave Radio Telescope (GMRT)
Radio Halo Survey (EGRHS) is an extension of the GMRT Radio Halo Survey (GRHS)
designed to search for radio halos using GMRT 610/235 MHz observations. The
GRHS+EGRHS consists of 64 clusters in the redshift range 0.2 -- 0.4 that have
an X-ray luminosity larger than 5x10^44 erg/s in the 0.1 -- 2.4 keV band and
with declinations > -31 deg in the REFLEX and eBCS X-ray cluster catalogues. In
this second paper in the series, GMRT 610/235 MHz data on the last batch of 11
galaxy clusters and the statistical analysis of the full sample are presented.
A new mini-halo in RXJ2129.6+0005 and candidate diffuse sources in Z5247, A2552
and Z1953 are discovered. A unique feature of this survey are the upper limits
on the detections of 1 Mpc sized radio halos; 4 new are presented here making a
total of 31 in the survey. Of the sample, 58 clusters that have adequately
sensitive radio information were used to obtain the most accurate occurrence
fractions so far. The occurrence of radio halos in our X-ray selected sample is
~22%, that of mini-halos is 13% and that of relics is ~5%. The radio power -
X-ray luminosity diagrams for the radio halos and mini-halos with the
detections and upper limits are presented. The morphological estimators namely,
centroid shift (w), concentration parameter (c) and power ratios (P_3/P_0)
derived from the Chandra X-ray images are used as proxies for the dynamical
states of the GRHS+EGRHS clusters. The clusters with radio halos and mini-halos
occupy distinct quadrants in the c-w, c-P_3/P_0 and w - P_3/P_0 planes,
corresponding to the more and less morphological disturbance, respectively. The
non-detections span both the quadrants.Comment: 24 pages, 5 tables, 25 figures, accepted for publication in A&
153 MHz GMRT follow-up of steep-spectrum diffuse emission in galaxy clusters
In this paper we present new high sensitivity 153 MHz Giant Meterwave Radio
Telescope follow-up observations of the diffuse steep spectrum cluster radio
sources in the galaxy clusters Abell 521, Abell 697, Abell 1682. Abell 521
hosts a relic, and together with Abell 697 it also hosts a giant very steep
spectrum radio halo. Abell 1682 is a more complex system with candidate steep
spectrum diffuse emission. We imaged the diffuse radio emission in these
clusters at 153 MHz, and provided flux density measurements of all the sources
at this frequency. Our new flux density measurements, coupled with the existing
data at higher frequencies, allow us to study the total spectrum of the halos
and relic over at least one order of magnitude in frequency. Our images confirm
the presence of a very steep "diffuse component" in Abell 1682. We found that
the spectrum of the relic in Abell 521 can be fitted by a single power-law with
from 153 MHz to 5 GHz. Moreover, we confirm that the halos
in Abell 521 and Abell 697 have a very steep spectrum, with
and respectively. Even with the inclusion of the 153 MHz
flux density information it is impossible to discriminate between power-law and
curved spectra, as derived from homogeneous turbulent re-acceleration. The
latter are favored on the basis of simple energetic arguments, and we expect
that LOFAR will finally unveil the shape of the spectra of radio halos below
100 MHz, thus providing clues on their origin.Comment: 11 pages, 6 figures, 3 tables, accepted for publication in A&
Functions and Therapeutic Potential of Extracellular Hsp60, Hsp70, and Hsp90 in Neuroinflammatory Disorders
Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin-proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. This deserves investigation because it may be at the core of neuroinflammation, and elucidation of its mechanism will open roads toward developing efficacious treatments centered on molecular chaperones (i.e., chaperonotherapy). Here, we discuss information available on the role of three members of the CS-heat shock protein (Hsp)60, Hsp70, and Hsp90-in IS modulation and neuroinflammation. These three chaperones occur intra- and extracellularly, with the latter being the most likely involved in neuroinflammation because they can interact with the IS. We discuss some of the interactions, their consequences, and the molecules involved but many aspects are still incompletely elucidated, and we hope that this review will encourage research based on the data presented to pave the way for the development of chaperonotherapy. This may consist of blocking a chaperone that promotes destructive neuroinflammation or replacing or boosting a defective chaperone with cytoprotective activity against neurodegeneration
The triad hsp60-mirnas-extracellular vesicles in brain tumors: Assessing its components for understanding tumorigenesis and monitoring patients
Brain tumors have a poor prognosis and progress must be made for developing efficacious treatments, but for this to occur their biology and interaction with the host must be elucidated beyond current knowledge. What has been learned from other tumors may be applied to study brain tumors, for example, the role of Hsp60, miRNAs, and extracellular vesicles (EVs) in the mechanisms of cell proliferation and dissemination, and resistance to immune attack and anticancer drugs. It has been established that Hsp60 increases in cancer cells, in which it occurs not only in the mitochondria but also in the cytosol and plasma-cell membrane and it is released in EVs into the extracellular space and in circulation. There is evidence suggesting that these EVs interact with cells near and far from their original cell and that this interaction has an impact on the functions of the target cell. It is assumed that this crosstalk between cancer and host cells favors carcinogenesis in various ways. We, therefore, propose to study the triad Hsp60-related miRNAs-EVs in brain tumors and have standardized methods for the purpose. These revealed that EVs with Hsp60 and related miRNAs increase in patients’ blood in a manner that reflects disease status. The means are now available to monitor brain tumor patients by measuring the triad and to dissect its effects on target cells in vitro, and in experimental models in vivo
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