3,978 research outputs found
Grasping the dialogical nature of acculturation
In this interesting article, Andreouli (2013). Identity and acculturation: The case of
naturalised citizens in Britain. Culture & Psychology, 19, 1–47) presents a dialogical perspective
on acculturation. To support this perspective, the author integrates the
Dialogical Self Theory and the Social Representations Theory. Drawing on her theoretical
explanation, we develop a conceptual review focused on two pairs of constructs –
social representations/I-positions and polyphasia/polyphonia. Andreouli’s empirical
study allowed her to operationalize some critiques about the two-dimensional perspective
and its strategies on acculturation. Nevertheless, it seems that the author ends up
replicating a more conventional and dual way of thinking. Their results give us privileged
access to the negotiation of meanings and activation of promoter signs or, in other
words, to the dialogical dynamics between I-positions. In this respect, we suggest that
the assumption of a more dialogic and semiotic lens could be an interesting further
development to this study
Enhancement of bulk second-harmonic generation from silicon nitride films by material composition
We present a comprehensive tensorial characterization of second-harmonic
generation from silicon nitride films with varying composition. The samples
were fabricated using plasma-enhanced chemical vapor deposition, and the
material composition was varied by the reactive gas mixture in the process. We
found a six-fold enhancement between the lowest and highest second-order
susceptibility, with the highest value of approximately 5 pm/V from the most
silicon-rich sample. Moreover, the optical losses were found to be sufficiently
small (below 6 dB/cm) for applications. The tensorial results show that all
samples retain in-plane isotropy independent of silicon content, highlighting
the controllability of the fabrication process.Comment: 4 pages, 3 figures, 2 tables; Re-submitted to Optics Letter
Triple minima in free energy of semiflexible polymers
We study the free energy of the worm-like-chain model, in the
constant-extension ensemble, as a function of the stiffness for finite chains
of length L. We find that the polymer properties obtained in this ensemble are
"qualitatively" different from those obtained using constant-force ensembles.
In particular we find that as we change the stiffness parameter, the polymer
makes a transition from the flexible to the rigid phase and there is an
intermediate regime of parameter values where the free energy has three minima
and both phases are stable. This leads to interesting features in the
force-extension curves.Comment: Published version, 4 pages, 5 figures, revte
Exploring Teachers PCK for Computational Thinking in Context
NWOAlgorithms and the Foundations of Software technolog
Reservoir Computing Approach to Robust Computation using Unreliable Nanoscale Networks
As we approach the physical limits of CMOS technology, advances in materials
science and nanotechnology are making available a variety of unconventional
computing substrates that can potentially replace top-down-designed
silicon-based computing devices. Inherent stochasticity in the fabrication
process and nanometer scale of these substrates inevitably lead to design
variations, defects, faults, and noise in the resulting devices. A key
challenge is how to harness such devices to perform robust computation. We
propose reservoir computing as a solution. In reservoir computing, computation
takes place by translating the dynamics of an excited medium, called a
reservoir, into a desired output. This approach eliminates the need for
external control and redundancy, and the programming is done using a
closed-form regression problem on the output, which also allows concurrent
programming using a single device. Using a theoretical model, we show that both
regular and irregular reservoirs are intrinsically robust to structural noise
as they perform computation
The prognostic value of the hypoxia markers CA IX and GLUT 1 and the cytokines VEGF and IL 6 in head and neck squamous cell carcinoma treated by radiotherapy ± chemotherapy
BACKGROUND: Several parameters of the tumor microenvironment, such as hypoxia, inflammation and angiogenesis, play a critical role in tumor aggressiveness and treatment response. A major question remains if these markers can be used to stratify patients to certain treatment protocols. The purpose of this study was to investigate the inter-relationship and the prognostic significance of several biological and clinicopathological parameters in patients with head and neck squamous cell carcinoma (HNSCC) treated by radiotherapy ± chemotherapy. METHODS: We used two subgroups of a retrospective series for which CT-determined tumoral perfusion correlated with local control. In the first subgroup (n = 67), immunohistochemistry for carbonic anhydrase IX (CA IX) and glucose transporter-1 (GLUT-1) was performed on the pretreatment tumor biopsy. In the second subgroup (n = 34), enzyme linked immunosorbent assay (ELISA) was used to determine pretreatment levels of the cytokines vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in serum. Correlation was investigated between tumoral perfusion and each of these biological markers, as well as between the markers mutually. The prognostic value of these microenvironmental parameters was also evaluated. RESULTS: For CA IX and GLUT-1, the combined assessment of patients with both markers expressed above the median showed an independent correlation with local control (p = 0.02) and disease-free survival (p = 0.04) with a trend for regional control (p = 0.06). In the second subgroup, IL-6 pretreatment serum level above the median was the only independent predictor of local control (p = 0.009), disease-free survival (p = 0.02) and overall survival (p = 0.005). CONCLUSION: To our knowledge, we are the first to report a link in HNSCC between IL-6 pretreatment serum levels and radioresistance in vivo. This link is supported by the strong prognostic association of pretreatment IL-6 with local control, known to be the most important parameter to judge radiotherapy responses. Furthermore, the combined assessment of CA IX and GLUT-1 correlated independently with prognosis. This is a valuable indication that a combined approach is important in the investigation of prognostic markers
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