369 research outputs found
What to do about banks
No full textCostas Lapavitsas considers the political economy of bloated finance and makes a case for establishing democratically-run public banks, which, he asserts, could strengthen the social and the collective in modern economies Copyright (c) 2009 The Author. Journal compilation (c) 2009 ippr.
Proteccion de Costas: Diseno de malecones y diques incluyendo un resumen de revestimientos
No full textSpanish translation of "Coastal Protection", including some additional papers for a course in La Habana. Introduccion a la protección de costas. Diseno de malecones y diques incluyendo un resumen de revestimientos. Recolección de datos y métodos de prediccion. Trepada de la ola y sobrepaso (hasta 1993). Estabilidad Estatica y Dinamica de materiales Sueltos (Jenstje Van Der Meer). Estabilidad hidraulica para materiales y systemas
Crisis Spaces : Structures, Struggles and Solidarity in Southern Europe
No full textReview Symposium of a book by Costas Hadjimichalis with reply from the author
Microbial biominers: Sequential bioleaching and biouptake of metals from electronic scraps
No full textAuthor contributions: Camino García-Balboa: conceptualization (lead), data curation (equal), formal analysis (equal), investigation (equal), writing–original draft (supporting), writing–review and editing (equal). Paloma Martínez-Alesón: conceptualization (supporting), formal analysis (supporting), investigation (equal), writing–original draft (supporting), writing–review and editing (equal). Victoria López-Rodas: funding acquisition (lead), supervision (equal), writing–review and editing (equal). Eduardo Costas: funding acquisition (lead), supervision (equal), writing–review and editing (equal). Beatriz Baselga-Cervera: conceptualization (supporting), data curation (equal), formal analysis (equal), funding acquisition (supporting), visualization (lead), writing–original draft (lead), writing–review and editing (lead).Electronic scraps (e‐scraps) represent an attractive raw material to mine demandedmetals, as well as rare earth elements (REEs). A sequential microbial‐mediated pro-cess developed in two steps was examined to recover multiple elements. First, wemade use of an acidophilic bacteria consortium, mainly composed of Acidiphiliummultivorum and Leptospidillum ferriphilum, isolated from acid mine drainages. Theconsortium was inoculated in a dissolution of e‐scraps powder and cultured for15 days. Forty‐five elements were analyzed in the liquid phase over time, includingsilver, gold, and 15 REEs. The bioleaching efficiencies of the consortium were >99%for Cu, Co, Al, and Zn, 53% for Cd, and around 10% for Cr and Li on Day 7. Thesecond step consisted of a microalgae‐mediated uptake from e‐scraps leachate. Thestrains used were two acidophilic extremotolerant microalgae, Euglena sp. (EugVP)and Chlamydomonas sp. (ChlSG) strains, isolated from the same extreme environ-ment. Up to 7.3, 4.1, 1.3, and 0.7 µg by wet biomass (WB) of Zn, Al, Cu, and Mn,respectively, were uptaken by ChlSG biomass in 12 days, presenting higher effi-ciency than EugVP. Concerning REEs, ChlSG biouptake 14.9, 20.3, 13.7, 8.3 ng ofGd, Pr, Ce, La per WB. Meanwhile, EugVP captured 1.1, 1.5, 1.4, and 7.5, respec-tively. This paper shows the potential of a microbial sequential process to revalorizee‐scraps and recover metals and REEs, harnessing extremotolerant microorganismsFundación Alfonso Martín EscuderoDepto. de Producción AnimalFac. de VeterinariaTRUEpu
Analysis of the spatio-temporal variability of spawning mackerel in the Northeast Atlantic
No full textThe northeast Atlantic (NEA) mackerel (Scomber scombrus) is a commercially significant species, with expansive spawning migrations occurring along the continental shelf of northwestern Europe. To identify the main variables influencing the spatial distribution of mackerel eggs, this study analyzed data from egg surveys conducted by the Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS) of the International Council for the Exploration of the Sea (ICES). To achieve this objective, a Random Forest model was used to predict the presence of mackerel eggs based on temporal, geographical, and environmental variables. Applying the Random Forest model to the survey data revealed that the main variables affecting mackerel spawning were the bottom depth, latitude, temperature, and salinity. Subsequently, Quotient Analysis was used to determine the optimal ranges of the key variables identified as influencing mackerel spawning. The results demonstrated a clear preference for spawning at depths between 100 m and 200 m, as well as a consistent preference for the area between 43° and 44° North, corresponding to the Cantabrian Sea. Furthermore, the results indicated that mackerel exhibited a considerable range of temperature tolerance throughout the spawning process, with a preference for cooler waters in the Western area in recent years. Salinity seems to have an effect on spawning at salinities between 35.0 ppm to 35.5 ppm, but results were imprecise. These results contribute to our understanding of how environmental and geographical variables influence the spawning behavior of NEA mackerel.The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.Peer reviewe
Prophéties créatrices et persistance des théories
No full textSelf fulfilling prophecies and persistence of theories
Costas Azariadis, Roger Guesnerie
The article studies paradoxal interactions between « beliefs » or « Theories » of agents and observed facts. It follows a previous article by the first author where examples of validation of « arbitrary » beliefs were given. Conclusions are extended hère by showing sufficient conditions for the existence of a stationnary stochastic equilibrinm reflecting the effect of « extrinsic » uncertainty (sunspots) on observed facts in a world without intrinsic uncertainty. When two subgroups in the population hold different beliefs based on the independant observation of two natural phenomena, the existence of a stochastic equilibrium validating statistically (at least weakly) both theories is shown.L'article est consacré à l'étude de certaines interactions paradoxales entre les représentants des agents économiques et les faits observés. Il approfondit la réflexion entreprise dans un article précédent d'Azariadis où l'auteur montrait des exemples de validation de croyances « arbitraires ». On étend ici les conclusions en exhibant des conditions suffisantes pour qu'en l'absence d'incertitude intrinsèque, une incertitude « extrinsèque » (les taches solaires) soit susceptible de conduire à des évolutions statistiquement compatibles avec les prévisions des agents. Dans le cas où deux groupes de la population ont des croyances distinctes fondées sur des observations indépendantes de phénomènes naturels différents (la « lune » et le « soleil »), on montre qu'il peut exister un équilibre stochastique validant statistiquement les deux théories. Cependant, ces deux « théories » pourraient être réfutées par un économètre sophistiqué et sceptique.Guesnerie Roger, Aziariadis Costas. Prophéties créatrices et persistance des théories. In: Revue économique, volume 33, n°5, 1982. pp. 787-806
Sub-Nyquist sampling and detection in Costas coded pulse compression radars
No full textModern pulse compression radar involves digital signal processing of high bandwidth pulses modulated with different coding schemes. One of the limiting factors in the radar’s design to achieve desired target range and resolution is the need of high rate analog-to-digital (A/D) conversion fulfilling the Nyquist sampling criteria. The high sampling rates necessitate huge storage capacity, more power consumption, and extra processing requirement. We introduce a new approach to sample wideband radar waveform modulated with Costas sequence at a sub-Nyquist rate based upon the concept of compressive sensing (CS). Sub-Nyquist measurements of Costas sequence waveform are performed in an analog-to-information (A/I) converter based upon random demodulation replacing traditional A/D converter. The novel work presents an 8-order Costas coded waveform with sub-Nyquist sampling and its reconstruction. The reconstructed waveform is compared with the conventionally sampled signal and depicts high-quality signal recovery from sub-Nyquist sampled signal. Furthermore, performance of CS-based detections after reconstruction are evaluated in terms of receiver operating characteristic (ROC) curves and compared with conventional Nyquist-rate matched filtering scheme.publishedVersionOpen Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were mad
Open dataset of scholars on Twitter
No full textIMPORTANT NOTE: This dataset was created using the May 2022 OpenAlex data dump. In June 2023, OpenAlex announced the implementation of a new author disambiguation algorithm that replaced all the old IDs with new ones, essentially making the dataset unusable. A new version of the dataset using the new OpenAlex author IDs is being prepared and will be available shortly.
This is a dataset of paired OpenAlex author_ids (https://docs.openalex.org/about-the-data/author) and tweeter_ids (usernames).
The dataset includes 492,124 unique author_ids and 423,920 unique tweeter_ids forming 498,672 unique author-tweeter pairs. The file contains the following columns:
Column
Description
author_id
author_id from OpenAlex
tweeter_id
tweeter_id of the Twitter user
criteria
A list of the different matching criteria that identified the pair
valid
This column indicates whether the match has been manually checked. A 0 indicates a false positive, and a 1 indicates a true positive. Empty rows have not been manually validated.
When using the dataset, please cite the following preprint which provides details about the matching process:
Mongeon, P., Bowman, T. D., & Costas, R. (2022). An open dataset of scholars on Twitter (arXiv:2208.11065). arXiv. https://doi.org/10.48550/arXiv.2208.11065
Links to R scripts can be found here: https://github.com/pmongeon/scholars-on-twitter/
Análisis bibliométrico de la actividad científica de los investigadores del CSIC en tres áreas, Biología y Biomedicina, Ciencia de los Materiales y Recursos Naturales : una aproximación metodológica a nivel micro (Web of Science, 1994-2004)
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