3,230 research outputs found
The Role of ICTs in Social Movements: The Case of the Honduran National Front Against the 2009 Coup
There is an important academic conversation happening about how social movements adopt, use, and configure Information and Communication Technologies (ICTs) for political participation. This dissertation contributes to that conversation by taking a holistic look at ICTs, throughout a social movement\u27s emergence and development, while considering its context, its organizational structures and sense-making processes.
I explore the case of the Honduran National Front Against the Coup (NFAC), a relevant case due to its similarities with other movements, like the use of social media, the support from the international community and its geographically dispersed networks; but also, particular in its political and ICT context.
Guided by the Contentious Politics Model (CPM) asked an overarching research question: What is the role of Information and Communication Technologies in the emergence and development of the National Front Against the Coup?
I also asked three second-level questions: (1) How does the Honduran Resistance Movement relate ICTs to political Opportunity Structures? (2) What role do ICTs play in creating and supporting the movement\u27s organizational structures, and in preparing and carrying out visible movement episodes? (3) How does the NFAC use ICTs to shape its attitudes, identities and competences?
I conducted a single embedded exploratory case study guided by the extended case method where I studied the NFAC in a sequence of interconnected time periods called Collective Action Framing Episodes (CAFEs). Data were reconstructive narratives from primary and secondary sources.
The movement\u27s use of ICTs for mobilizing social support for their cause can be considered an improvised subversive response to the institutionalized political environment.
The movement\u27s regional affiliates formed a loosely coupled extended organization, which allowed the affiliates a degree of autonomy to do their oppositional work while remaining fully aligned with the movement\u27s priorities. ICTs allowed the movement to broadcast its messages across the network to socialize the affiliates and ensure they were all on the same page. This lose confederation, coordinated through ICTs allowed the NFAC to dynamically reconfigure and rearrange its regional affiliates as needed.
I found instances of resourcefulness and improvisation, both in the way individual media platforms were used, and in the way these platforms were combined and recombined to move ahead.
Thus, the intellectual contribution of this study is twofold: The first one is an expansion of the CPM (Contentious Politics Model). I propose that ICTs don\u27t drive revolutions, but neither are they simply tools. There is a dynamic relation as environmental conditions (OS) like policies, institutions, ICT ownership, media centralization, shape the way social movements configure ICTs, and ICTs configurations by social movements can influence environmental conditions. The same way ICT configurations can be determined by he availability, collaboration and connectedness of civil society organizations within the movement (MS), and their relations can be influenced by ICT configurations. Therefore, by playing a reflexive role in the process of frame creation, ICTs are embedded in every level of the social movement emergence and development.
The second contribution is an operative framework and analytical tool to study the interactions between social movements, institutions, and ICTs. The model uses CAFEs (Collective Action Framing Episodes), a composed construct that allows integrating several levels of analysis into one unit of analysis
Orbital and physical parameters of eclipsing binaries from the All-Sky Automated Survey catalogue - VI. AK Fornacis - a rare, bright K-type eclipsing binary
We present the results of the combined photometric and spectroscopic analysis
of a bright (V=9.14), nearby (d=31 pc), late-type detached eclipsing binary AK
Fornacis. This P=3.981 d system has not been previously recognised as a
double-lined spectroscopic binary, and this is the first full physical model of
this unique target. With the FEROS, CORALIE and HARPS spectrographs we
collected a number of high-resolution spectra in order to calculate radial
velocities of both components of the binary. Measurements were done with our
own disentangling procedure and the TODCOR technique, and were later combined
with the photometry from the ASAS and SuperWASP archives. We also performed an
atmospheric analysis of the component spectra with the Spectroscopy Made Easy
(SME) package. Our analysis shows that AK For consists of two active, cool
dwarfs having masses of and
M and radii of and
R, slightly less metal abundant than the Sun. Parameters of both
components are well reproduced by the models.
AK For is the brightest system among the known eclipsing binaries with K or M
type stars. Its orbital period is one of the longest and rotational velocities
one of the lowest, which allows us to obtain very precise radial velocity
measurements. The precision in physical parameters we obtained places AK For
among the binaries with the best mass measurements in the literature. It also
fills the gap in our knowledge of stars in the range of 0.5-0.8 M, and
between short and long-period systems. All this makes AK For a unique benchmark
for understanding the properties of low-mass stars.Comment: 9 pages, 11 figures, 3 tables, accpeted for publication in A&
Application of the Gaussian mixture model in pulsar astronomy -- pulsar classification and candidates ranking for {\it Fermi} 2FGL catalog
Machine learning, algorithms to extract empirical knowledge from data, can be
used to classify data, which is one of the most common tasks in observational
astronomy. In this paper, we focus on Bayesian data classification algorithms
using the Gaussian mixture model and show two applications in pulsar astronomy.
After reviewing the Gaussian mixture model and the related
Expectation-Maximization algorithm, we present a data classification method
using the Neyman-Pearson test. To demonstrate the method, we apply the
algorithm to two classification problems. Firstly, it is applied to the well
known period-period derivative diagram, where we find that the pulsar
distribution can be modeled with six Gaussian clusters, with two clusters for
millisecond pulsars (recycled pulsars) and the rest for normal pulsars. From
this distribution, we derive an empirical definition for millisecond pulsars as
. The two
millisecond pulsar clusters may have different evolutionary origins, since the
companion stars to these pulsars in the two clusters show different chemical
composition. Four clusters are found for normal pulsars. Possible implications
for these clusters are also discussed. Our second example is to calculate the
likelihood of unidentified \textit{Fermi} point sources being pulsars and rank
them accordingly. In the ranked point source list, the top 5% sources contain
50% known pulsars, the top 50% contain 99% known pulsars, and no known active
galaxy (the other major population) appears in the top 6%. Such a ranked list
can be used to help the future follow-up observations for finding pulsars in
unidentified \textit{Fermi} point sources.Comment: 9 pages, 4 figures, accepted by MNRA
Electroconvulsive therapy mediates neuroplasticity of white matter microstructure in major depression.
Whether plasticity of white matter (WM) microstructure relates to therapeutic response in major depressive disorder (MDD) remains uncertain. We examined diffusion tensor imaging (DTI) correlates of WM structural connectivity in patients receiving electroconvulsive therapy (ECT), a rapidly acting treatment for severe MDD. Tract-Based Spatial Statistics (TBSS) applied to DTI data (61 directions, 2.5 mm(3) voxel size) targeted voxel-level changes in fractional anisotropy (FA), and radial (RD), axial (AD) and mean diffusivity (MD) in major WM pathways in MDD patients (n=20, mean age: 41.15 years, 10.32 s.d.) scanned before ECT, after their second ECT and at transition to maintenance therapy. Comparisons made at baseline with demographically similar controls (n=28, mean age: 39.42 years, 12.20 s.d.) established effects of diagnosis. Controls were imaged twice to estimate scanning-related variance. Patients showed significant increases of FA in dorsal fronto-limbic circuits encompassing the anterior cingulum, forceps minor and left superior longitudinal fasciculus between baseline and transition to maintenance therapy (P<0.05, corrected). Decreases in RD and MD were observed in overlapping regions and the anterior thalamic radiation (P<0.05, corrected). Changes in DTI metrics associated with therapeutic response in tracts showing significant ECT effects differed between patients and controls. All measures remained stable across time in controls. Altered WM microstructure in pathways connecting frontal and limbic areas occur in MDD, are modulated by ECT and relate to therapeutic response. Increased FA together with decreased MD and RD, which trend towards normative values with treatment, suggest increased fiber integrity in dorsal fronto-limbic pathways involved in mood regulation
Towards an Amazonian Urbanism Collective infrastructures of Care
In the everchanging and mobile territory of the Amazon rainforest, the imposition of a rural-urban divide results in the unsustainability of settlements that appeared as sites of extraction at the turn of the twentieth century. Accelerated changes and transformations in urbanisation patterns and in climatic conditions call for the necessity to explore alternative city-making models that are better able to adapt to and promote multiple ways of being and of interdependence between humans and nature. The lifestyles and worldvisions of Amazonian urbanites already speak of the possibilities of reimagining what Christine Padoch calls ‘urban forests and rural cities.’ Through collective experimentation, we depict how the co-production of collective infrastructures of care could allow strengthening the relational socio-natural practices needed for a reconfiguration of Amazonian urbanism
PHP59 Exploring the Health and Living Standards of Those Who Don't Report Their Migration Status in a Population-Based Survey: The Case of Chile
Enzymatic transesterification of urethane-bond containing ester
Here we demonstrate the feasibility and successful application of enzymes in polyurethane network synthesis as well as occurring hurdles that have to be addressed when using urethanes synthesis substrates. The enzymatic transesterification of an urethane-bond containing monofunctional ester and a model alcohol carbitol using lipases is discussed. The reaction is optimized in terms of transesterification time and temperature, the reaction solvent, the possibility of a cosolvent and the alcohol amount, the used transesterification environment, and the biocatalyst. Enzymatic cross-linking of polyurethanes can open up a pool of new possibilities for cross-linking and related polyurethane network properties due to the enzymes high enantio-, stereo-, and regioselectivity and broad substrate spectrum. [Figure not available: see fulltext.
Lipase-Catalyzed Transamidation of Urethane-Bond-Containing Ester
Significant improvement in mechanical properties and shape recovery in polyurethanes can be obtained by cross-linking, usually performed in a traditional chemical fashion. Here, we report model studies of enzymatic transamidations of urethane-bond-containing esters to study the principles of an enzymatic build-up of covalent cross-linked polyurethane networks via amide bond formation. The Lipase-catalyzed transamidation reaction of a urethane-bond-containing model ester ethyl 2-(hexylcarbamoyloxy)propanoate with various amines is discussed. A side product was formed, that could be successfully identified, and its synthesis reduced to a minimum
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