Human pressures on two estuaries of the Iberian Peninsula are reflected in food web structure

As a result of the increased urban and agricultural development in coastal environments, estuaries are among the most modified and threatened aquatic ecosystems. This study used stable isotopes to examine the effects of human impacts by contrasting the food web structures of two Iberian estuaries exposed to different degrees of human pressure. More complex feeding pathways were found in the more altered estuary (Guadalquivir). Greater spread among species along the carbon axis suggests that the primary consumers exploit organic matter with various origins, whereas different nitrogen signals of the secondary consumers suggest that they feed on different suites of prey. In contrast, the similar isotopic signals of secondary consumers in the relatively little influenced estuary (Guadiana) suggests similarity in diet composition and feeding on the same organic matter sources. Understanding trophic interactions in estuaries is vital for defining proper management and conservation, and the preliminary data provided here are one step in this direction

Minimal Surfaces as an Innovative Solution for the Design of an Additive Manufactured Solar-Powered Unmanned Aerial Vehicle (UAV)

[EN] This paper aims to describe the methodology used in the design and manufacture of a fixed-wing aircraft manufactured using additive techniques together with the implementation of technology based on solar panels. The main objective is increasing the autonomy and range of the UAV¿s au-tonomous missions. Moreover, one of the main targets is to improve the capabilities of the aero-nautical industry towards sustainable aircrafts and to acquire better mechanical properties owing to the use of additive technologies and new printing materials. Further, a lower environmental impact could be achieved through the use of renewable energies. Material extrusion (MEX) technology may be able to be used for the manufacture of stronger and lighter parts by using gy-roids as the filling of the printed material. The paper proposes the use of minimal surfaces for the reinforcement of the UAV aircraft wings. This type of surface was never used because it is not possible to manufacture it using conventional techniques. The rapid growth of additive technolo-gies led to many expectations for new design methodologies in the aeronautical industry. In this study, mechanical tests were carried out on specimens manufactured with different geometries to address the design and manufacture of a UAV as a demonstrator. In addition, to carry out the manufacture of the prototype, a 3D printer with a movable bench similar to a belt, that allows for the manufacture of parts without limitations in the Z axis, was tested. The parts manufactured with this technique can be structurally improved, and it is possible to avoid manufacturing mul-tiple prints of small parts of the aircraft that will have to be glued later, decreasing the mechanical properties of the UAV. The conceptual design and manufacturing of a solar aircraft, SolarÍO, us-ing additive technologies, is presented. A study of the most innovative 3D printers was carried out that allowed for the manufacture of parts with an infinite Z-axis and, in addition, a filler based on minimal surfaces (gyroids) was applied, which considerably increased the mechanical properties of the printed parts. Finally, it can be stated that in this article, the potential of the ad-ditive manufacturing as a new manufacturing process for small aircrafts and for the aeronautical sector in the future when new materials and more efficient additive manufacturing processes are already developed is demonstrated.This research received partial funding from the Government of Spain under the project PID2019-108807RB-I00 and Generalitat Valenciana under IDIFEDER/2021/040.García-Gascón, C.; Castelló-Pedrero, P.; García Manrique, JA. (2022). Minimal Surfaces as an Innovative Solution for the Design of an Additive Manufactured Solar-Powered Unmanned Aerial Vehicle (UAV). Drones. 6(10):1-27. https://doi.org/10.3390/drones610028512761

Landscape construction and time reckoning in Iron Age Celtic Iberia

In this paper, we report on three areas of the Iberian Peninsula that were occupied at least during the Iron Age and the early stages of Romanisation, where observations of astronomical phenomena in the landscape, rock carvings, and Latin inscriptions point to a particular method of time reckoning. All of these sites have previously been connected with the Celtic culture. The knowledge of the natural world that Classical sources assigned to these peoples need not have been reflected in a monolithic calendrical system used by all Celtic communities on the Continent. In fact, such a ‘Celtic calendar’ may have had different expressions in different areas, expressed in different ways, although sharing some common characteristics such as the particual use of the lunar and solar cycles.V članku poročamo o treh območjih na Iberskem polotoku, ki so bila poseljena vsaj od železne dobe in začetka romanizacije, kjer smo na podlagi opazovanj astronomskih fenomenov v pokrajini, na podlagi skalnih rezbarij in latinskih napisov prepoznali posebno metodo merjenja časa. Vsa predstavljena najdišča so bila doslej povezana s keltsko kulturo. Znanje o naravi in svetu, ki so ga klasični viri pripisali Keltom, se ni nujno odražalo v monolitskem koledarskem sistemu, ki so ga uporabljale vse keltske skupnosti na celini. Takšen ‘keltski koledar’ se je lahko v različnih območjih izražal na drugačne načine, vendar je pri tem ohranil nekatere skupne značilnosti, kot je npr. posebna uporaba Luninih in Sončevih ciklov

Pathways of economically relevant demersal species in the Ibiza channel from a lagrangian backtracking approach

This work studies the most probable spatial origin of demersal species that eventually reach the Ibiza Channel after a dispersion stage, a region where water masses with different characteristics choke. Demersal species are assumed to be in a planktonic stage in which they behave as passive particles, being only advected by the dominant ocean currents. To find the origin we have performed a set of backward Lagrangian simulations using a high-resolution model of currents. As a result, we obtain the preferred pathways of dispersion for demersal species. A careful analysis of pathways provides useful information on the spatiotemporal variability of demersal and their origin weeks ago before they reach the Ibiza Channel. This information is very valuable from a conservation standpoint to determine the key regions that should be protected as eggs and larvae exportation areas.Peer Reviewe

Perceptually Equivalent Resolution in Handheld Devices for Streaming Bandwidth Saving

We present the description, results, and analysis of the experiments conducted to find the equivalent resolution associated with handheld devices. That is, the resolution from which users stop perceiving quality improvements if better resolutions are presented to them in such devices. Thus, it is the maximum resolution that it is worth considering for generating and delivering video, as long as sequences are not too intensively compressed. Therefore, the detection of the equivalent resolutions allows for notable savings in bandwidth consumption. Subjective assessments have been carried out on fifty subjects using a set of video sequences of very different nature and four handheld devices with a broad range of screen dimensions. The results prove that the equivalent resolution in current handheld devices is 720p as higher resolutions are not valued by users

From multi to single-particle analysis: a seasonal spectroscopic study of airborne particulate matter in Zaragoza, Spain

It is distinguished that deficient outdoor air quality is responsible for substantial health and climate issues. The aim of our study was to investigate the air quality in the city of Zaragoza (Spain) by characterizing atmospheric particulate matter (PM10) during two seasons (winter and spring). PM10 samples were collected in 2022 in quartz filters through a low-volume sampler and chemically analysed by complementary analytical techniques: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), Laser Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy (RS) and Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS). Results have revealed, together with a temperature inversion phenomenon in winter, the presence of both natural (Al, Ca, Mg, Ti, Sr, Fe, etc.) and anthropogenic particles. The latter mainly formed by black carbon with an origin on fossil fuel combustion emissions. Additionally, chemical analyses of PM10 filters showed the presence of three types of microplastics suspended in the air of the city: polyethylene terephthalate (PET), polyamides (PA) and polystyrene (PS). The results obtained from this research are of special interest to take into account for future air quality policies, particularly those with the aim of reducing air pollution in cities

Calendrical Deer, Time-Reckoning and landscape in Iron-Age North-West Spain

The volumen title is ASTRONOMY AND COSMOLOGY IN FOLK TRADITIONS AND CULTURAL HERITAGE Edited by Jonas Vaigkunas. Archaeologia Baltica volume 10 was prepared by Klaipėda University Institute of Baltic Sea Region History and Archaeology and Museum of Molėtai district. Published with a grant from the Ministry of Education and Science of The Republic of Lithuania.[EN]The relationship between petroglyphs and archaeoastronomy has been treated in several ways in the past. In the present study we examine a particular motif found among the rock carvings in the north-west of the Iberian Peninsula: a large deer with over-sized horns and an unnatural number of tips on each horn. A multidisciplinary approach combining landscape archaeology, comparative history of religions, and archaeoastronomy suggests a coherent interpretation of the motif. It reveals a unique amalgamation of calendrical motives, landscape relationships and lunisolar events. It may also be significant in relation to the Celtic world-view and its artistic manifestation, and to the relationship between time and landscape.This work is partially financed under the framework of projects P310793 `Arqueoastronomia' of the Instituto de Astrofísica de Canarias, AYA2004-01010 `Orientatio ad Sidera' of the Spanish Ministry of Education and Science, and project PGIDITO6PXIB236147PR `Arqueología e relixión no noroeste peninsular' of the Xunta de Galicia.Peer reviewe

Thracian dolmens and their orientations

The volumen title is ASTRONOMY AND COSMOLOGY IN FOLK TRADITIONS AND CULTURAL HERITAGE Edited by Jonas Vaigkunas. Archaeologia Baltica volume 10 was prepared by Klaipėda University Institute of Baltic Sea Region History and Archaeology and Museum of Molėtai district. Published with a grant from the Ministry of Education and Science of The Republic of Lithuania.[EN]Spread over south-eastern Bulgaria, northern Greece and the European part of Turkey are a large number of megalithic tombs. These dolmens were built from around the twelfth century BC to about the sixth century BC. The monuments were built with well cut slabs, defining a rectangular space with a roof. A small hole marks the entrance. A dromos is also present in some dolmens and all of these structures used to be covered by a tumulus. We present the first results from a series of campaigns devoted to measuring the orientation of these structures. The first campaign was carried out in the Strandja Mountains where 31 dolmens (among other monuments) were measured. The dolmens are not orientated at random, and a particular pattem of orientation has been found for the entrance of these monuments. Several tentative explanations are attempted and supported with information provided by contemporary Greek sources.This work is partially financed under the framework of the projects P310793 `Arqueoastronomia' of the Instituto de Astrofísica de Canarias and AYA2004-01010 `Orientatio ad Sidera' of the Spanish Ministry of Education and Science.Peer reviewe

Factors Considered in the Assessment of Computer Science Engineering Capstone Projects and their Influence on Discrepancies between Assessors

A capstone project is an extensive learning experience traditionally developed during a student’s final academic year. Assessing such a complex assignment involves several challenges and is usually based upon the evaluations of at least two different people: the capstone project advisor, and one or more other assessors. Quantitative studies comparing only different assessors' grades and qualitative studies investigating the origin of possible discrepancies have been conducted. In both cases, contradictory conclusions were reached. The objective of this study is to analyze the factors that are given consideration by assessors of engineering capstone projects and the influence of these factors on the discrepancies between different assessors’ opinions of the same project. This study quantitatively examined 162 computer science engineering capstone projects developed by one student and supervised by one advisor. Each project was assessed by the project advisor and a committee. For each project, the advisor and the committee were asked to complete an additional questionnaire on product characteristics, student competences, and project supervision. Competences demonstrated by the student were found to be the most relevant element when a capstone project was evaluated by the advisor and the committee; product characteristics were found to be second in influence. Furthermore, advisors grant minor significance to the advisor-involvement component. Discrepancies between grades seem to be associated with those aspects to which one assessor has access, while the other does not, such as student skills demonstrated during project development or their performance in the oral defense. Both the advisor’s and the committee’s perspectives are important in the assessment of this complex task and they complement one another