Searching for tidal tails around ω\omega Centauri using RR Lyrae Stars

We present a survey for RR Lyrae stars in an area of 50 deg$^2$ around the globular cluster $\omega$ Centauri, aimed to detect debris material from the alleged progenitor galaxy of the cluster. We detected 48 RR Lyrae stars of which only 11 have been previously reported. Ten among the eleven previously known stars were found inside the tidal radius of the cluster. The rest were located outside the tidal radius up to distances of $\sim 6$ degrees from the center of the cluster. Several of those stars are located at distances similar to that of $\omega$ Centauri. We investigated the probability that those stars may have been stripped off the cluster by studying their properties (mean periods), calculating the expected halo/thick disk population of RR Lyrae stars in this part of the sky, analyzing the radial velocity of a sub-sample of the RR Lyrae stars, and finally, studying the probable orbits of this sub-sample around the Galaxy. None of these investigations support the scenario that there is significant tidal debris around $\omega$ Centauri, confirming previous studies in the region. It is puzzling that tidal debris have been found elsewhere but not near the cluster itself.Comment: 11 pages, 11 figures, Accepte

Photoprotective compounds as early markers to predict holm oak crown defoliation in declining Mediterranean savannahs

This research was mainly funded by the Spanish Government through the IBERYCA project (CGL2017-84723-P) and its associated FPI scholarship BES-2014-067971 (to M.E.-V.). It was further supported by the BC3 María de Maeztu excellence accreditation (MDM-2017-0714; the Spanish Government) and by the BERC 2018-2021 and the UPV/EHU-GV IT-1018-16 program (Basque Government). Additionally, this research was further supported through the ‘Juan de la Cierva program’ (the Spanish Government to M.V.; (IJCI-2017-34640).) and two projects funded by the Romanian Ministry of Education and Research through UEFISCDI (NATIvE, PN-III-P1-1.1-PD- 2016-0583 and REASONING, PN-III-P1-1.1-TE-2019-1099 to A.-M.H.)

Alteration of the tree–soil microbial system triggers a feedback loop that boosts holm oak decline

In anthropic savanna ecosystems from the Iberian Peninsula (i.e. dehesa), complex interactions between climate change, pathogen outbreaks and human land use are presumed to be behind the observed increase in holm oak decline. These environmental disturbances alter the plant–soil microbial continuum, which can destabilize the ecological balance that sustains tree health. Yet, little is known about the underlying mechanisms, particularly the directions and nature of the causal–effect relationships between plants and soil microbial communities. In this study, we aimed to determine the role of plant–soil feedbacks in climate-induced holm oak decline in the Iberian dehesa. Using a gradient of holm oak health, we reconstructed key soil biogeochemical cycles mediated by soil microbial communities. We used quantitative microbial element cycling (QMEC), a functional gene-array-based high-throughput technique to assess microbial functional potential in carbon, nitrogen, phosphorus and sulphur cycling. The onset of holm oak decline was positively related to the increase in relative abundance of soil microbial functional genes associated with denitrification and phosphorus mineralization (i.e. nirS3, ppx and pqqC; parameter value: 0.21, 0.23 and 0.4; p < 0.05). Structural equation model (χ2 = 32.26, p-value = 0.73), moreover, showed a negative association between these functional genes and soil nutrient availability (i.e. mainly mineral nitrogen and phosphate). Particularly, the holm oak crown health was mainly determined by the abundance of phosphate (parameter value = 0.27; p-value < 0.05) and organic phosphorus (parameter value = −0.37; p-value < 0.5). Hence, we propose a potential tree–soil feedback loop, in which the decline of holm oak promotes changes in the soil environment that triggers changes in key microbial-mediated metabolic pathways related to the net loss of soil nitrogen and phosphorus mineral forms. The shortage of essential nutrients, in turn, affects the ability of the trees to withstand the environmental stressors to which they are exposed. Read the free Plain Language Summary for this article on the Journal blog. © 2023 The Authors. Functional Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.This research has been mainly funded by the Spanish Government through the IBERYCA project (CGL2017‐84723‐P), its associated FPI scholarship BES‐2014‐067971 (ME‐V), the SMARTSOIL (PID2020‐113244GB‐C21) and SMARTHEALTH (PID2020‐113244GA‐C22) projects (both funded by MCIN/AEI/10.13039/501100011033). It has been further supported by the BC3 María de Maeztu excellence accreditation (MDM‐2017‐0714; the Spanish Government), by the BERC 2018–2021 and by the UPV/EHU‐GV IT‐1648‐22 (from the Basque Government). Additionally, this research was further supported through the grant Holistic management practices, modelling and monitoring for European forest soils—HoliSoils (EU Horizon 2020 Grant Agreement No 101000289) and the ‘Juan de la Cierva programme’ (MV; IJCI‐2017‐34640; the Spanish Government). We acknowledge the Nutrilab‐URJC (Mostoles, Spain) laboratory services for the soil chemical analyses and SGIker of UPV/EHU (Leioa, Spain) for the technical and staff support for the high‐throughput quantitative‐PCR analysis. We also thank the private owners of the dehesas for facilitating our access to their properties. We are thankful to Celia López‐Carrasco Fernández and the ‘Consejería de Agricultura, Medioambiente y Desarrollo rural de la Junta de Castilla‐La Mancha’ for all the logistical support. The ‘Tree’ icon by Hey Rabbit illustrator, from thenounproject.com were used to design the Graphical abstract. Open Access funding provided by the Univer

Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula

Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high

Shadow analysis: A method for measuring soil surface roughness

Erosion potential and the effects of tillage can be evaluated from quantitative descriptions of soil surface roughness. The present study therefore aimed to fill the need for a reliable, low-cost and convenient method to measure that parameter. Based on the interpretation of micro-topographic shadows, this new procedure is primarily designed for use in the field after tillage. The principle underlying shadow analysis is the direct relationship between soil surface roughness and the shadows cast by soil structures under fixed sunlight conditions. The results obtained with this method were compared to the statistical indexes used to interpret field readings recorded by a pin meter. The tests were conducted on 4-m2 sandy loam and sandy clay loam plots divided into 1-m2 subplots tilled with three different tools: chisel, tiller and roller. The highly significant correlation between the statistical indexes and shadow analysis results obtained in the laboratory as well as in the field for all the soil–tool combinations proved that both variability (CV) and dispersion (SD) are accommodated by the new method. This procedure simplifies the interpretation of soil surface roughness and shortens the time involved in field operations by a factor ranging from 12 to 20

Actividad bacteriocinogénica de bacterias aisladas de digestivos de peces marinos salvajes

El crecimiento exponencial que ha sufrido la acuicultura en las últimas décadas ha dado lugar a un incremento en número y virulencia de las enfermedades bacterianas que afectan a los peces cultivados. Hasta la fecha, el control de estas enfermedades se ha realizado a través del uso de vacunas y antibióticos, así como de la desinfección del agua y el control biológico, el uso de inmunoestimulantes no-específicos y suplementos dietéticos, entre otros. Pero una mala gestión de estas enfermedades, asociada sobre todo al abuso de antibióticos, ha sido asociada a la aparición de reservorios de bacterias resistentes a antibióticos, tanto en animales como en el ambiente acuático, con el consiguiente peligro para la salud humana (1, 2). El empleo de bacteriocinas como alternativa a los antibióticos parece ser una alternativa plausible para el control y tratamiento de estas enfermedades de una manera inocua y sostenible (3, 4). Pese a que en los últimos años se ha intensificado la búsqueda de cepas productoras de bacteriocinas frente a bacterias patógenas marinas, desafortunadamente todavía son pocas las cepas totalmente caracterizadas (5). El presente estudio tiene por objetivo caracterizar cepas bacterianas con actividad bacteriocinogénica aisladas de intestinos de peces salvajes del Mar Cantábrico. Para ello se procesaron un total de 19 intestinos pertenecientes a 19 ejemplares, cada uno de una especie diferente capturados en el Mar Cantábrico (Cantabria). De estas muestras se aislaron un total de 198 colonias en medio de cultivo TSA, en base a su morfología, color y brillo, que fueron seleccionadas para comprobar su actividad antagonista frente a patógenos de peces de acuicultura. Como cepas indicadoras patógenas de peces se emplearon: Vibrio splendidus y Vibrio anguillarum, y cepas patógenas aisladas de cultivos de lenguado senegalés (Solea senegalensis). Se detectaron 15 cepas de bacterias marinas que presentaban actividad antagonista frente al menos una de las cepas patógenas, de las cuales 4 mostraron actividad inhibitoria frente a más de una especie patógena. La identificación de las cepas procedentes del medio marino seleccionadas se realizó mediante la secuenciación del gen 16S ARN, presentando una homología >99% a Myroides sp. y Alcaligenes sp. Finalmente se estudió el efecto de los parámetros físico-químicos en la actividad bactericida (pH, temperatura y proteasas)

Multifractal Analysis of Soil Surface Roughness

Soil surface roughness (SSR) is a parameter highly suited to the study of soil susceptibility to wind and water erosion. The development of a methodology for quantifying SSR is therefore instrumental to soil evaluation. We developed such a method, based on the multifractal analysis (MFA) of soil elevation measurements collected at the intersections on a 2- by 2-cm2 grid in a 200- by 200-cm2 plot. Samples were defined using the gliding box algorithm (GB), in which a box of a given size "glides" across the grid map in all possible directions. The advantage of the GB over the box counting algorithm is that it yields a greater number of large sample sizes, which usually leads to better statistical results. Standard deviation, semivariogram fractal dimension, and semivariogram crossover length were estimated for all scenarios to compare the results of SSR multifractal analysis to indices found with traditional techniques. For its high sensitivity to the spatial arrangement implicit in a data set, MFA appears to be better suited than classical indices to compare plots tilled under different management criteria. The results showed that MFA is able to effectively reflect the heterogeneity and complexity of agricultural SSR. Based on this type of analysis, two new indices have been defined to compare the multifractal spectrum characteristics of the raw data to the characteristics of a random field with the same average and SD

Exploring APOE genotype effects on Alzheimer's disease risk and amyloid β burden in individuals with subjective cognitive decline: The FundacioACE Healthy Brain Initiative (FACEHBI) study baseline results

Introduction: Subjective cognitive decline (SCD) has been proposed as a potential preclinical stage of Alzheimer's disease (AD). Nevertheless, the genetic and biomarker profiles of SCD individuals remain mostly unexplored. Methods: We evaluated apolipoprotein E (APOE) ε4's effect in the risk of presenting SCD, using the Fundacio ACE Healthy Brain Initiative (FACEHBI) SCD cohort and Spanish controls, and performed a meta-analysis addressing the same question. We assessed the relationship between APOE dosage and brain amyloid burden in the FACEHBI SCD and Alzheimer's Disease Neuroimaging Initiative cohorts. Results: Analysis of the FACEHBI cohort and the meta-analysis demonstrated SCD individuals presented higher allelic frequencies of APOE ε4 with respect to controls. APOE dosage explained 9% (FACEHBI cohort) and 11% (FACEHBI and Alzheimer's Disease Neuroimaging Initiative cohorts) of the variance of cerebral amyloid levels. Discussion: The FACEHBI sample presents APOE ε4 enrichment, suggesting that a pool of AD patients is nested in our sample. Cerebral amyloid levels are partially explained by the APOE allele dosage, suggesting that other genetic or epigenetic factors are involved in this AD endophenotype

Overexpression of Human and Fly Frataxins in Drosophila Provokes Deleterious Effects at Biochemical, Physiological and Developmental Levels

10 pages, 5 figures. 21779322[PubMed] PMCID: PMC3136927BACKGROUND: Friedreich's ataxia (FA), the most frequent form of inherited ataxias in the Caucasian population, is caused by a reduced expression of frataxin, a highly conserved protein. Model organisms have contributed greatly in the efforts to decipher the function of frataxin; however, the precise function of this protein remains elusive. Overexpression studies are a useful approach to investigate the mechanistic actions of frataxin; however, the existing literature reports contradictory results. To further investigate the effect of frataxin overexpression, we analyzed the consequences of overexpressing human (FXN) and fly (FH) frataxins in Drosophila. METHODOLOGY/PRINCIPAL FINDINGS: We obtained transgenic flies that overexpressed human or fly frataxins in a general pattern and in different tissues using the UAS-GAL4 system. For both frataxins, we observed deleterious effects at the biochemical, histological and behavioral levels. Oxidative stress is a relevant factor in the frataxin overexpression phenotypes. Systemic frataxin overexpression reduces Drosophila viability and impairs the normal embryonic development of muscle and the peripheral nervous system. A reduction in the level of aconitase activity and a decrease in the level of NDUF3 were also observed in the transgenic flies that overexpressed frataxin. Frataxin overexpression in the nervous system reduces life span, impairs locomotor ability and causes brain degeneration. Frataxin aggregation and a misfolding of this protein have been shown not to be the mechanism that is responsible for the phenotypes that have been observed. Nevertheless, the expression of human frataxin rescues the aconitase activity in the fh knockdown mutant. CONCLUSION/SIGNIFICANCE: Our results provide in vivo evidence of a functional equivalence for human and fly frataxins and indicate that the control of frataxin expression is important for treatments that aim to increase frataxin levels.This work was supported by grants from Fondo Investigaciones Sanitarias (ISCIII06- PI0677) and La Fundació la Marató TV3 (exp 101932) of Spain. JVL is supported by the European Friedreich's Ataxia Consortium for Translational Studies. SS is a recipient of a fellowship from Ministerio de Ciencia e Innovación of Spain.Peer reviewe