Paesaggio linguistico e atmosfere. Alcune riflessioni metodologiche

Beyond the significant results achieved in field research, the study of the Linguistic Landscape (LL) offers a testing ground for the theoretical and categorical changes that have impacted the latest sociolinguistic research. It is in fact through this concept that linguistic studies have participated in the so-called ‘spatial turn’ so pervasive in the human and social sciences in recent decades marked by an increasingly complex interpretation of space. Compared with this debate’s other arenas, however, sociolinguistic research has so far proved to be less attentive to consideration of the affective component of space, which always involves a person who experiences it, perceives it, crosses it, works in it, speaks it (lived space). By means of a novel crossing with the notion of atmosphere, developed by the new aesthetic of phenomenological orientation to indicate the emotional feel of human space, the present essay aims to question the conception of landscape itself at the base of sociolinguistic research, opening the way to a more complex and articulated analytical model that can more effectively tackle key dimensions of the contemporary linguistic experience, such as speakers’ modes of perception and representation in urban spaces characterized by growing plurilingualism

Lifelong Learning of Spatiotemporal Representations with Dual-Memory Recurrent Self-Organization

Artificial autonomous agents and robots interacting in complex environments are required to continually acquire and fine-tune knowledge over sustained periods of time. The ability to learn from continuous streams of information is referred to as lifelong learning and represents a long-standing challenge for neural network models due to catastrophic forgetting. Computational models of lifelong learning typically alleviate catastrophic forgetting in experimental scenarios with given datasets of static images and limited complexity, thereby differing significantly from the conditions artificial agents are exposed to. In more natural settings, sequential information may become progressively available over time and access to previous experience may be restricted. In this paper, we propose a dual-memory self-organizing architecture for lifelong learning scenarios. The architecture comprises two growing recurrent networks with the complementary tasks of learning object instances (episodic memory) and categories (semantic memory). Both growing networks can expand in response to novel sensory experience: the episodic memory learns fine-grained spatiotemporal representations of object instances in an unsupervised fashion while the semantic memory uses task-relevant signals to regulate structural plasticity levels and develop more compact representations from episodic experience. For the consolidation of knowledge in the absence of external sensory input, the episodic memory periodically replays trajectories of neural reactivations. We evaluate the proposed model on the CORe50 benchmark dataset for continuous object recognition, showing that we significantly outperform current methods of lifelong learning in three different incremental learning scenario

Gluon propagation inside a high-energy nucleus

We show that, in the light-cone gauge, it is possible to derive in a very simple way the solution of the classical Yang-Mills equations for the collision between a nucleus and a proton. One important step of the calculation is the derivation of a formula that describes the propagation of a gluon in the background color field of the nucleus. This allows us to calculate observables in pA collisions in a more straightforward fashion than already proposed. We discuss also the comparison between light-cone gauge and covariant gauge in view of further investigations involving higher order corrections.Comment: 12 pages, 2 figure

Baryon stopping and saturation physics in relativistic collisions

We investigate baryon transport in relativistic heavy-ion collisions at energies reached at the CERN Super Proton Synchrotron, BNL Relativistic Heavy-Ion Collider (RHIC), and CERN LHC in the model of saturation. An analytical scaling law is derived within the color glass condensate framework based on small-coupling QCD. Transverse momentum spectra, net-baryon rapidity distributions and their energy, mass and centrality dependences are well described. In a comparison with RHIC data in Au + Au collisions at sqrt (s_NN) = 62.4 GeV and 200 GeV, the gradual approach to the gluon saturation regime is investigated, and limits for the saturation-scale exponent are determined. Predictions for net-baryon rapidity spectra and the mean rapidity loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.52 TeV are made.Comment: 11 pages, 10 Figures; improved figure inscriptions, corrected typos, minor changes in text/titl

Baryon Stopping as a new Probe of Geometric Scaling

We suggest to use net-baryon rapidity distributions in central relativistic heavy-ion collisions at SPS, RHIC and LHC energies in order to probe saturation physics. Within the color glass condensate framework based on small-coupling QCD, net-baryon rapidity distributions are shown to exhibit geometric scaling. In a comparison with RHIC data in Au + Au collisions at sqrt(s_NN) = 62.4 GeV and 200 GeV the gradual approach to the gluon saturation regime is investigated. Predictions for net-baryon rapidity spectra and the mean rapidity loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.5 TeV are made.Comment: 4 pages 3 figures; calculation and figures now for net baryons instead of net protons; modified conclusion

Antiangular Ordering of Gluon Radiation in QCD Media

We investigate angular and energy distributions of medium-induced gluon emission off a quark-antiquark antenna in the framework of perturbative QCD as an attempt toward understanding, from first principles, jet evolution inside the quark-gluon plasma. In-medium color coherence between emitters, neglected in all previous calculations, leads to a novel mechanism of soft-gluon radiation. The structure of the corresponding spectrum, in contrast with known medium-induced radiation, retains some properties of the vacuum case; in particular, it exhibits a soft divergency. However, as opposed to the vacuum, the collinear singularity is regulated by the pair opening angle, leading to a strict angular separation between vacuum and medium-induced radiation, denoted as antiangular ordering. We comment on the possible consequences of this new contribution for jet observables in heavy-ion collisions.Comment: 4 pages, 2 figures; v2. a number of minor improvements, figures updated, accepted for publication in PR

Jet thermalization in QCD kinetic theory

We perform numerical studies in QCD kinetic theory to investigate the energy and angular profiles of a high energy parton - as a proxy for a jet produced heavy ion collisions - passing through a Quark-Gluon Plasma (QGP). We find that the fast parton loses energy to the plasma mainly via a radiative turbulent gluon cascade that transport energy locally from the jet down to the temperature scale where dissipation takes place. In this first stage, the angular structure of the turbulent cascade is found to be relatively collimated. However, when the lost energy reaches the plasma temperature is it rapidly transported to large angles w.r.t. the jet axis and thermalizes. We investigate the contribution of the soft jet constituents to the total jet energy. We show that for jet opening angles of about 0.3 rad or smaller the effect is negligible. Conversely, larger opening angles become more and more sensitive to the thermal component of the jet and thus to medium response. Our result showcase the importance of the jet cone size in mitigating or enhancing the details of dissipation in jet quenching observables.Comment: 41 pages, 11 figures

Penerapan Penuntun Praktikum dengan Menggunakan Metode Discovery Learning untuk Meningkatkan Hasil Belajar Siswa pada Materi Larutan Elektrolit dan Nonelektrolit

Permasalahan dalam pembelajaran kimia yaitu beragam pemahaman siswa terhadap suatu materi, siswa kurang memahami konsep kimia yang diajarkan. Tujuan penelitian ini untuk melihat hasil belajar siswa  & menerapkan penuntun praktikum dengan menggunakan metode discovery learning. Instrumen yang digunakan dalam penelitian ini adalah lembar validasi penuntun praktikum. Teknik pengumpulan data menggunakan metode wawancara, observasi dan angket. Hasil validasi dari beberapa ahli yang terdiri dari tiga validator mununjukan bahwa penuntun praktikum berada pada kategori valid dengan presentasi 86,84 . Berdasarkan hasil penelitian dapat disimpulkan bahwa hasil belajar siswa yang menggunakan penuntun praktikum dengan menggunakan metode discovery learning mencapai nilai KKM dan 70% siswa melampaui nilai KKM ( Kriteria Ketuntasan Minimal) yang ditetapkan

Lutte contre les trois bruches Acanthoscelides obtectus (Say, 1893), Bruchus rufimanus Boheman, 1833 et Collosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae : Bruchinae) par les huiles essentielles extraites d'Origanum glandulosum (Lamiacées)

Els olis essencials extrets per destiŀlació del vapor de la planta aromàtica Origanum glandulosum (Lamiacées) han estat testats a diferents dosis en els adults de tres espècies de brúquids, Acanthoscelides obtectus (brúquid del fesol), Bruchus rufimanus (brúquid de la fava) i Callosobruchus maculatus (brúquid dels cigrons), a una temperatura de 27 ºC i a una humitat relativa del 75 %. Aquests olis tenen activitat insecticida i hem observat a més una reducció significativa de la posta d?ous en comparació amb el control a les femelles de les tres espècies de brúquids estudiats. Els valors DL50 calculats després de 48 h d?exposició mostren que els olis essencials testats són molt tòxics en A. obtectus, amb una DL50 = 1,44 μl/ 30 g de llavors, presenten una toxicitat una mica variable en C. maculatus, amb una DL50 = 2,06 μl/ 30 g de llavors, i són menys tòxics en B. rufimanus, amb una DL50 = 7,72 μl/ 30 g de llavors. L?anàlisi de la composició química mostra la riquesa dels olis essencials en compostos coneguts per les seves propietats insecticides com l?α-pinè, limonè, el carvacrol i el timol, la qual cosa explica els resultats obtinguts.The essential oils extracted by hydrodistillation from the aromatic plant Origanum glandulosum (Lamiacées) were tested with various amounts on the adults of three beetles Acanthoscelides obtectus (bruchid of bean), Bruchus rufimanus, (bruchid of broad bean) and Callosobruchus maculatus (bruchid of chickpea), at a temperature of 27 ºC and a relative humidity of 75 %. These oils present an insecticidal activity and induce in the females of the three studied beetles a significant reduction of the laying compared with that in the control. The DL50 calculated after 48h of exposure, show the essential oils tested are very toxic on A. obtectus with DL 50 = 1,44 μl/ 30 g of seeds, have a little variable toxicity on C. maculatus with DL 50 = 2.06 μl/ 30 g of seeds, and less toxic on B. rufimanus with DL 50 = 7.72 μl/ 30 g of seeds. The analysis of the chemical composition shows the richness of essential oils in compounds known for their insecticidal properties like the α-pinene, limonene, carvacrol, and the thymol, which explains the results obtained