Universidad de Cádiz

Recent evidence supports that, prior to the impact of modern humans, the temperate zone of Europe was not dominated by a closed continuous forest, but consisted of heterogeneous landscapes with grasslands, light woodlands and forests. Until the late Pleistocene, this region held a diverse community of megaherbivores that maintained the open and semi‐open vegetation through grazing and browsing. This new baseline is congruent with the fact that many European woody species are light‐demanding and fail to regenerate in the shaded interiors of temperate forests. Notably, most of these species are dispersed by frugivorous and seed‐caching animals, mostly birds. Nowadays, avian seed dispersers play a key role for the connectivity and expansion of woodland patches in fragmented anthropogenic landscapes. Indeed, avian seed dispersal within and across the deforested matrix is the norm rather than the exception. Here, I reflect on the current patterns of avian seed dispersal in the fragmented anthropogenic landscapes of Europe from a Pleistocene perspective. The aim of this exercise is to discuss linkages between past and present landscapes, seeking an historical understanding of the high spatial complementarity of avian seed dispersal in and out of the forests. Synthesis: I conclude that the spatial patterns of avian seed dispersal in anthropogenic landscapes are congruent with an ecological and evolutionary history with open and semi‐open habitats created and maintained by megaherbivores (ecological memory). By shaping the environmental conditions for millions of years, megaherbivores would have created selective pressures on animals and plants for life in landscape mosaics with forests and open habitats (niche construction). Finally, I discuss differences in landscape patterns today and in the Pleistocene, as well as the generality of these ideas to other biogeographical regions.

This work delves into the quotient of an affine semigroup by a positive integer , exploring its intricate properties and broader implications. We unveil an associated tree that serves as a valuable tool for further analysis. Moreover, we successfully generalize several key irreducibility results, extending their applicability to the more general class of $\mathcal {C}$ C -semigroup quotients. To shed light on these concepts, we introduce the novel notion of an arithmetic variety of affine semigroups , accompanied by illuminating examples that showcase its power.

Membrane separation technology has found widespread application in molecular sieving and water reclamation. Its use in organic solvent nanofiltration (OSN) has been limited by the modest permeation rates and stability of existing membranes. In this study, 2D clay nanolaminated membranes are engineered, derived from the stacking of exfoliated vermiculite nanosheets, as a potential solution for OSN. The as‐synthesized clay membrane displayed limited stability in both water and solvents due to rapid hydration or solvation of the nanosheets. To enhance the membrane's stability and sieving capabilities, cations of various valences (K⁺, Na⁺, Mg²⁺, Ca²⁺, Fe³⁺) are intercalated into the interlayer of the clay nanosheets. The resulting cation‐treated clay membranes display considerable enhancement in structural stability in both aqueous and organic media. Subsequently, the solvent transport behavior and separation performance of these clay membranes are evaluated and described by molecular dynamic simulation and experiments. It is identified that Fe‐intercalated nanolaminates demonstrate controllable stacking order, resulting in enhanced sieving performance with a rejection rate of over 95% for Methyl Orange and a methanol permeation rate of ≈165 L m⁻² h⁻¹ bar⁻¹ [LMHB]. The findings of this work pave the way for the practical applications of 2D nanolaminated clay membranes in OSN.

The invasion of the brown seaweed Rugulopteryx okamurae is altering the equilibrium and reducing the biodiversity of marine coastal ecosystems in southern Europe, with negative economic consequences for fishermen, tourists and governments that regularly remove tons of sediment from the coast. However, the large amount of biomass produced also implies an opportunity for the valorization of these seaweeds, for example in the form of biofertilizer and/or biostimulant for agricultural use. In this study we characterized the biochemical composition of R. okamurae and aqueous extracts. The annual compositional variation of the seaweed was studied by measuring the concentrations of carbohydrates, lipids, proteins, minerals, phenolic compounds, and antioxidants, as well as the concentrations of metals and micro/macroelements, in samples collected in two consecutive years from southern Spain. The composition of the seaweed varied between years for macro/micronutrients, metals, proteins, polyphenols and lipids (mainly terpenes), while polysaccharides (fucoidan, laminarin and alginate) remained at similar concentrations. The seaweed composition highlighted the terpene concentration mainly in 2023. The aqueous extracts significantly increased the fucoidan and laminarin fractions compared to those of the seaweed. Overall, the biochemical characterization results suggest that R. okamurae is valuable as a biofertilizer due to its mineral content (K, Ca, Fe, Mn), while the extract compositions (sulfur, polyphenolic, fucoidan, laminarin, and glycolipid) suggest its potential use as a biostimulant. Thus, this study proposes that R. okamurae is a valuable source for agricultural use.

This paper explores the limitations faced by current solutions for selecting quasi-identifying attributes in the context of Privacy-Preserving Data Publishing (PPDP). PPDP stipulates that any published personal data should not be linkable to other available data sources in a manner that could potentially lead to individual re-identification or compromise sensitive data. The state-of-the-art methods for selecting quasi-identifying attributes commonly rely on heuristic evaluations to assess the risk of re-identification associated with each attribute. We hypothesize that these heuristic-based methods could be significantly improved by complementing them with empirical methods capable of quantifying the external linkability of dataset attributes. This empirical layer would enable a fine-tuning of the obfuscation of attributes within the dataset, thereby preventing the unnecessary privatization of attributes beyond potential attackers’ reach while ensuring privatization of those easily accessible. For this purpose, we explore recent advancements in identifying semantically related datasets across heterogeneous data sources. Although initially developed for purposes beyond privacy preservation, these methods support our initiative by uncovering potential links with external data and thus providing empirical evidence for the identification of attributes as quasi-identifiers. Finally, we discuss potential pathways to implement this empirical layer in quasi-identifier identification systems.

Climate change is forcing species to shift their distribution ranges. Animal seed dispersers might be particularly important in assisting plants tracking suitable climates to higher elevations. However, this role is still poorly understood due to a lack of comprehensive multi‐guild datasets along elevational gradients. We compiled seed dispersal networks for the five altitudinal vegetation belts of the Tenerife Island (0–3718 m above sea level) to explore how plant and animal species might facilitate the mutual colonisation of uphill habitats under climate change. The overall network comprised 283 distinct interactions between 73 plant and 27 animal species, with seed dispersers offering viable pathways for plants to colonise upper vegetation belts. A pivotal role is played by a lizard as island‐level hub, while four birds and one introduced mammal (rabbit) are also important connectors between belts. Eleven plant species were empirically found to be actively dispersed to elevations beyond their current known range, with observed vertical dispersal distances largely surpassing those required to escape climate change. Furthermore, over half of the plants arriving at higher elevations were exotic. Functionally diverse disperser communities are crucial for enabling plants tracking climate change on mountains, but exotic plants might particularly benefit from this upward lift.

This paper describes the microplastic problems on five sandy beaches along the Skikda coastline (southwestern Mediterranean, northeastern Algeria), defining their magnitudes, spatial-temporal distributions, shapes, polymer types, impacts, and potential sources. The data presented in this study were collected during two field surveys in May (spring) and September (autumn/fall) of 2019. Overall, the average abundance of microplastics across all beaches was 6174 items/m2 in spring and 6183 items/m2 in autumn, representing the highest level of MPs ever reported in Algeria. The most common microplastic types found were fragments, pellets, foams and fibers, accounting for >98 % of the microplastic shapes collected in this study. Our findings highlight the persistence of MPs on the studied beaches and that environmental factors such as currents, wind directions, beaching, sedimentation, dunes, and fragmentation all significantly impact the distribution and accumulation of plastic debris on beaches.

Background Stability during early postnatal life in preterm infants is related to better outcomes. Although vital signs are monitored continuously in Neonatal Intensive Care Unites, this monitoring does not include all physiological parameters nor data such as movement patterns. Although there are scattered sources of data, there is no centralized data hub for neonates information. Results We have created the first neonate data hub for easy and interactive access to upload or download postural, physiological, and medical data of neonates: NeoVault. NeoVault is a platform that provides access to information through two interfaces: 1) via a Web interface (designed for medical personnel, data scientists, researchers); and 2) via a RESTful API (Application Programming Interfaces) -designed for developers-, aiming to integrate access to information into third-party applications. The web access allows searching and filtering according to specific parameters, visualization of data through graphs and images, and generation of datasets in CSV format. Access through the RESTful API is described in OpenAPI, enabling access to information from any device, facilitating it in an interoperable format. Currently, it contains nearly 800,000 postural records and 3.000 physiological data entries. The physiological and postural data stored for each neonate in NeoVault are collected through the NRP (Neonates Recording Platform) tool, which allows for the automatic and reliable collection of data. Conclusion NeoVault is an open platform for simple access to postural, physiological, and medical data of neonates that can be utilized by researchers, data scientists, medical personnel, and programmers. It enables integration into third-party applications and the generation of customized datasets.

A continuous linear operator L defined on the space of entire functions $\mathcal {H}({\mathbb {C}})$ is said to be an extended $\lambda$-eigenoperator of the differentiation operator D provided $DL=\lambda LD$. Here we fully characterize when an extended $\lambda$-eigenoperator of D is supercyclic, it has a hypercyclic subspace or it has a supercyclic subspace.

In this work, we explore a new dispersive liquid–liquid microextraction (DLLME) method to selectively separate chemical species of Cd and Zn in saline waters. It is based on the use of the magnetic ionic liquid (MIL) methyltrioctylammonium tetrachloroferrate ([N 1,8,8,8 ⁺ ][FeCl 4 ⁻ ]), which allows an efficient and environmentally friendly extraction of the target species. In addition, the paramagnetic component in the MIL simplifies the separation step required in DLLME, allowing for fast separation and recovery of the extracted species with a magnet, without a centrifugation step. The optimum conditions for the separation by MIL-DLLME were 3.3 mg mL ⁻¹ MIL, sample pH = 8, and an extraction time of 30 min. Under these conditions, metal chlorocomplexes (99.7% and 81.0% of total metal concentration for Cd and Zn, respectively) were quantitatively separated, remaining the free cations in the aqueous samples. In a second step, the extracted metal species were back-extracted with 1 mol L ⁻¹ HNO 3 and a re-extraction time of 15 min. For cadmium, this acidic solution separated the neutral complex CdCl 2 (60.5%), while CdCl ⁺ (21.5%) and CdCl 3 ⁻ (18.1%) remained in the organic phase. For Zn, the anionic complex ZnCl 3 ⁻ (17.3%) was retained by the organic reagent, while ZnCl 2 (45.7%) and ZnCl ⁺ (37.0%) were re-extracted by the nitric acid solution. The separation of the chemical species of metals along the three liquid phases used allowed their quantification in several samples of real seawater and a certified reference material. Graphical Abstract

Hyperglucagonemia has been implicated in the pathogenesis of type 2 diabetes (T2D). In contrast to β-cells, studies on the function of the pancreatic α-cell in T2D are scarce. Consequently, the processes underlying hyperglucagonemia and α-cell dysfunction are largely unknown, limiting the appropriate design of specific pharmacological and therapeutic strategies. In the current study, we aimed to analyze the alterations of the pancreatic α-cell and its glucagon responses in diabetic db/db mice at early stages of the disease. In this context of glucose intolerance, hyperinsulinemia, and β-cell dysfunction, hyperglucagonemia was only present at fed conditions and was associated with insulin resistance. Yet, we found that the glucagon-to-insulin ratio in db/db mice did not change with fed or fasted states, further supporting that the metabolic regulation of glucagon release was impaired. Pancreatic β-cell dysfunction in db/db mice was manifested by increased basal secretion from isolated islets along with reduced insulin content. In contrast, α-cells from diabetic animals presented upregulated secretion and islet content of glucagon compared with controls. Electrophysiological analysis of dispersed α-cells revealed that altered secretion was not the result of impaired exocytosis. Instead, we found defective regulation of Ca²⁺ signaling by glucose. Besides these functional alterations, we also observed augmented α-cell mass in diabetic mice, which was accompanied by disrupted islet cytoarchitecture as well as increased α-cell size and number, without pieces of evidence of upregulated proliferation. Overall, these findings indicate that hyperglucagonemia in early T2D results from multifaceted α-cell deregulation in mice.

Objectives Cognitive processes underlying learning are essential for educational practice. Therapeutic interventions that incorporate mindfulness to enhance these processes are becoming increasingly popular, but few studies focused on the effectiveness of their application to the educational setting for the development of executive functioning. The objective of this study was to assess the effects of a neuroeducational program based on mindfulness techniques applied in the classroom on the executive functioning of second grade primary school students. Method Forty-eight students were included, 25 in the passive control group and 23 in the intervention group. Participants were assessed before and after program implementation with the CARAS-R test to measure selective attention, the WISC-V Digits Span subtest to measure working memory, and the NEPSY-II Inhibition subtest to measure cognitive flexibility and inhibition. Results Changes between pre- and post-intervention scores were analyzed separately for the control and experimental groups, and effect sizes were calculated to estimate the significance of the differences. Conclusions Although both groups improved on the cognitive measures evaluated, our results indicate that the mindfulness-based program significantly improved students’ working memory, inhibition, and cognitive flexibility. We conclude that this type of program can help teachers improve their educational practice with methodologies that promote the integral development of their students. Preregistration This study is not preregistered.

Objective The objective of this paper is to quantify muscle load using Theraband elastic bands across seven resistance intensities. Methods Bands were profiled using a force sensor, standardized to 200 cm length, and manually stretched. Measurements for each band were twice recorded at 11 distances and converted to percentages for standardization. Results Equations derived from Theraband resistance properties were established (kg = ((elastic constant) ± SE) × percentage of elongation). The standard error ranged from 0.0007 to 0.069, while the coefficient of determination ranged from 0.977 to 0.995. Conclusion This study provides quantification of resistance across various intensities of Theraband elastic band, offering equations for estimating external load.

The performance of photovoltaic modules in the field plays a crucial role in ensuring reliability, quality, and financing for photovoltaic installations. Recent years have witnessed exponential growth in the solar photovoltaic industry, potentially driven by the principles of Industry 5.0. In this digital transformation era, companies can enhance production efficiency, mitigate environmental impact, and transition towards a more sustainable and profitable manufacturing model. Therefore, it is imperative to examine the stress conditions encountered by photovoltaic modules during the manufacturing process, as they are a major contributing factor to field failures. The objective of the article is to prolong the lifespan of photovoltaic panels by addressing various stages of their manufacturing, aiming to identify enhancements that will result in prolonged durability. This extension is closely linked to the performance of photovoltaic modules where the article finds solutions such as a modification on the rigidity of the encapsulant to reduce stresses, cooling in different ways to reduce temperature or change the angle of inclination to avoid dust accumulation. Additionally, this phase presents an opportune moment to reduce greenhouse gas emissions, further aligning the process with sustainability goals. Furthermore, the article analyzes the advantages and disadvantages of different photovoltaic cell technologies. While the current market is dominated by c-Si technology, significant increases are expected in the adoption of other technologies highlighting the use of bifacial cells in the coming years.

Purpose The aim was to translate and adapt The Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL‐RSI) to Spanish and provide evidence of its psychometric properties and responsiveness in a both sexes multisport sample. Methods ACL‐RSI Spanish version (SP ACL‐RSI) was obtained by forward‐back‐translation method. Internal consistency, test‐retest reliability, construct validity and responsiveness were assessed. Standardized response mean (SRM), smallest detectable change (SDC) and minimally important change (MIC) were obtained by anchor‐based method. The sample consisted of n = 132 multisport patients who underwent ACL‐RSI. Sixty‐seven patients (Group A) completed test‐retest of the SP ACL‐RSI within 15 days and 65 patients (Group B) fulfilled SP ACL‐RSI, the Tampa Scale of Kinesiophobia (TSK‐11), the International Knee Documentation Committee‐Subjective Knee Form (IKDC‐SF 2000), the Knee Osteoarthritis Outcome Score (KOOS) preoperative, 6 and 12 months. Results The SP ACL‐RSI shows satisfactory internal consistency (Cronbach's α = 0.95) and test–retest reliability (ICC = 0.92), with acceptable floor (9%) and ceiling (6%) effects. Convergent validity was supported with moderate positive correlations with KOOS and IKDC‐SF 2000 dimensions, and a negative correlation with the TSK (p < 0.001). For SDC responsiveness, a high effect was observed with SRM = 0.97 at 12 months, and the MIC for SP ACL‐RSI was 15. Conclusions The SP ACL‐RSI is as valid and reliable as the original for measuring emotions, confidence in performance, and re‐injury risk on return to sport after ACL‐R in Spanish‐speaking multisport practitioners of both sexes. Moreover, it shows acceptable responsiveness, performing better at the group level than the individual level. Level of evidence A cohort study (diagnosis); Level II of evidence.

Aims Understanding the linkage between community heterogeneity (β diversity) and ecosystem functioning is crucial for uncovering complex ecological processes that impact ecosystem stability and productivity. However, our understanding of how β diversity is associated with ecosystem functioning across environmental gradients remains limited. Methods We conducted an aridity-gradient transect survey of grassland over 3500 km across the Tibetan Plateau (a total of 80 grassland sites) to investigate the changes of plant and soil microbial diversities along a natural aridity gradient, and to evaluate the above- and belowground biomass and plant nutrient levels connected with the observed variation. Results Our results showed that plant richness, above- and belowground biomass, plant nutrient concentrations, and soil microbial α and β diversities (including taxonomic and functional) significantly decreased along the aridity gradient. Compared to the α diversities of plant and microbial community, their β diversities were more significantly correlated with above- and belowground biomass and plant carbon, nitrogen and phosphorus concentrations. Metagenomic functional profiles showed that β diversity of microbial functions, including genes of the carbohydrate metabolism responsible for carbon degradation, nitrification, energy production and conversion, material transport and coenzyme metabolism, had closer associations with plant biomass and nutrient concentrations than did their α diversities. These positive β biodiversity-functions association was weakened by the increasing aridity, mainly because the increasing aridity-induced lower biomass of plant functional groups (e.g., sedge and forbs), soil moisture and organic carbon content decreased both plant and soil microbial β diversities. Conclusions These findings provide novel insight into the biodiversity-ecosystem functions relationship and stress the crucial roles of above- and belowground β diversity in supporting alpine grassland biomass and nutrient levels. Biodiversity conservation to prevent large-scale community homogenization should be attached in alpine ecosystem.