Building intersubjectivity in blended problem-solving tasks

This paper aims to shed light on the process of building intersubjectivity between student-student dyads in a blended educational context. Three girls and five boys, 17 to 18 years old, participated in two types of problem-solving tasks. They formed four dyads and were required to negotiate aloud what to post in a web-forum. Dyads were video recorded, with eight sessions in total. The same pairs participated in both tasks. We are interested in understanding how the intersubjective processes were affected by the tasks and by the dyads. The two tasks differ concerning the structure of the problems. The first task was based on two short papers – one pro and other con – referring to a problem close to students' real life: the use of digital devices in class. The second problem was based on perspective-taking: dyads were required to imagine “How would the school of the future look in 20 years.” Data were analysed through a purpose-built codebook, comprising five macro-categories and 21 subcategories. Altogether, our results indicate an effect of both the type of task and of dyads' specific style of interaction. Nevertheless, a five-step process featuring intersubjectivity was found. Practical implications for teachers and educators are highlighted

The Impact of TikTok Policies on Information Flows during Times of War: Evidence of ‘Splinternet’ and ‘Shadow-Promotion’ in Russia

This research discusses how TikTok’s adaptation to Russian war censorship laws after the invasion of Ukraine affected content accessibility and prioritization on the platform. The study uses a combination of scraping and sock-puppet algorithmic audits to understand the impact of platform policy on information flows during times of war. The first test found that TikTok restricted access to non-Russian content in Russia, resulting in a 95% reduction of available content in the country. The second test revealed that TikTok unevenly applied its content policies, allowing pro-war content to proliferate in Russia despite its claim of enforcing a ban on new content uploads in the country. The third test highlighted a case of “shadow-promotion,” i.e., the prioritization of content supposed to be banned. The study's findings emphasize the need to monitor the platform's policy decisions during times of conflict, as they can contribute to the creation of a 'Splinternet.' The study also underscores the significant power that social media companies wield in shaping information flows during times of war and highlights the need to closely monitor platform policy decisions during such times. The article also provides recommendations for implementing the DSA in the EU context, which could help avoid problems such as those encountered while monitoring the platform in Russia

(2E)-2-[(3E)-4-Phenyl­but-3-en-2-yl­idene]hydrazinecarboxamide

In the title compound, C11H13N3O, the phenyl ring is disordered over two sites, with occupancy factors in a 0.520 (17):0.480 (17) ratio. The dihedral angle between the ring planes of the major and minor components of the disordered ring is 12.9 (2)°. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming R 2 2(8) ring motifs. C—H⋯O, C—H⋯N and C—H⋯π inter­actions also occur

Anatomical atlas of the upper part of the human head for electroencephalography and bioimpedance applications

Objective. The objective of this work is to develop a 4D (3D+T) statistical anatomical atlas of the electrical properties of the upper part of the human head for cerebral electrophysiology and bioimpedance applications. Approach. The atlas was constructed based on 3D magnetic resonance images (MRI) of 107 human individuals and comprises the electrical properties of the main internal structures and can be adjusted for specific electrical frequencies. T1w+T2w MRI images were used to segment the main structures of the head while angiography MRI was used to segment the main arteries. The proposed atlas also comprises a time-varying model of arterial brain circulation, based on the solution of the Navier-Stokes equation in the main arteries and their vascular territories. Main results. High-resolution, multi-frequency and time-varying anatomical atlases of resistivity, conductivity and relative permittivity were created and evaluated using a forward problem solver for EIT. The atlas was successfully used to simulate electrical impedance tomography measurements indicating the necessity of signal-to-noise between 100 and 125 dB to identify vascular changes due to the cardiac cycle, corroborating previous studies. The source code of the atlas and solver are freely available to download. Significance. Volume conductor problems in cerebral electrophysiology and bioimpedance do not have analytical solutions for nontrivial geometries and require a 3D model of the head and its electrical properties for solving the associated PDEs numerically. Ideally, the model should be made with patient-specific information. In clinical practice, this is not always the case and an average head model is often used. Also, the electrical properties of the tissues might not be completely known due to natural variability. Anatomical atlases are important tools for in silico studies on cerebral circulation and electrophysiology that require statistically consistent data, e.g. machine learning, sensitivity analyses, and as a benchmark to test inverse problem solvers.Peer reviewe

2,5-Dimethoxy­benzaldehyde thio­semicarbazone

In the title mol­ecule, C10H13N3O2S, the dihedral angle between benzene and –N—C(=S)—N—N=C– planes is 9.20 (6)°. The two meth­oxy groups are coplanar with the benzene ring [C—O—C—C torsion angles of −2.31 (18) and −6.45 (17)°]. In the crystal structure, mol­ecules are linked by inter­molecular N—H⋯S, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network

GASTRO library I: the simulated chemodynamical properties of several GSE-like stellar halos

The Milky Way stellar halo contains relics of ancient mergers that tell the story of our Galaxy's formation. Some of them are identified due to their similarity in energy, actions and chemistry, referred to as the "chemodynamical space", and are often attributed to distinct merger events. It is also known that our Galaxy went through a significant merger event that shaped the local stellar halo during its first Gyr. Previous studies using $N$-body only and cosmological hydrodynamical simulations have shown that such single massive merger can produce several "signatures" in the chemodynamical space, which can potentially be misinterpreted as distinct merger events. Motivated by these, in this work we use a subset of the GASTRO, library which consists of several SPH+$N$-body models of single accretion event in a Milky Way-like galaxy. Here, we study models with orbital properties similar to the main merger event of our Galaxy and explore the implications to known stellar halo substructures. We find that: $i.$ supernova feedback efficiency influences the satellite's structure and orbital evolution, resulting in distinct chemodynamical features for models with the same initial conditions, $ii.$ very retrograde high energy stars are the most metal-poor of the accreted dwarf galaxy and could be misinterpreted as a distinct merger $iii.$ the most bound stars are more metal-rich in our models, the opposite of what is observed in the Milky Way, suggesting a secondary massive merger, and finally $iv.$ our models can reconcile other known substructures to an unique progenitor.Comment: Published in Ap