The miniJPAS survey : white dwarf science with 56 optical filters

Aims. We analyze the white dwarf population in miniJPAS, the first square degree observed with 56 medium-band, 145 Å in width optical filters by the Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS), to provide a data-based forecast for the white dwarf science with low-resolution (R ∼ 50) photo-spectra. Methods. We define the sample of the bluest point-like sources in miniJPAS with r 7000 K can be segregated from the bluest extragalactic QSOs, providing a clean sample based on optical photometry alone. Conclusions. The J-PAS low-resolution photo-spectra would produce precise effective temperatures and atmospheric compositions for white dwarfs, complementing the data from Gaia. J-PAS will also detect and characterize new white dwarfs beyond the Gaia magnitude limit, providing faint candidates for spectroscopic follow-up

The Dominant Role of Mergers in the Size Evolution of Massive Galaxies since z∼1

We estimate the merger rate, both major (stellar mass ratio μ = M★,_2/M★,_1 ≥ 1/4) and minor (1/10 ≤ μ < 1/4), of massive (M★ ≥ 10^(11) M☉) early-type galaxies (ETGs) in the COSMOS field by close pairs statistics. The merger rate of massive ETGs evolves as a power-law (1+z)^n, showing the minor merger little evolution with redshift, n_(mm) ∼ 0, in contrast with the increase of major mergers, n_(MM) = 1.8. Our results shows that massive ETGs have undergone 0.89 mergers (0.43 major and 0.46 minor) since z ∼ 1, leading to a mass growth of ∼ 30%. In addition, μ ≥ 1/10 mergers can explain ∼ 55% of the observed size evolution of these galaxies since z ∼ 1. Another ∼ 20% is due to the progenitor bias (younger galaxies are more extended) and we estimate that very minor mergers (μ < 1/10) could contribute with an extra ∼ 20%. The remaining ∼ 5% should come from other processes (e.g., adiabatic expansion or observational effects). These results suggest that mergers are the main contributor to the size evolution of massive ETGs, accounting for ∼ 55%–75% of that evolution in the last 8 Gyr. Nearly half of this merging evolution is related with minor (μ < 1/4) events

Robust determination of the major merger fraction at z = 0.6 in Groth Strip

(Abridged) We measure the fraction of galaxies undergoing disk-disk major mergers (f_m) at intermediate redshifts (0.35 <= z < 0.85) by studying the asymmetry index A of galaxy images. Results are provided for B- and Ks-band absolute magnitude selected samples from the Groth strip in the GOYA photometric survey. Three sources of systematic error are carefully addressed: (i) we avoid morphological K-corrections, (ii) we measure asymmetries in artificially redshifted to z_d = 0.75 galaxies to lead with loss of morphological information with redshift, and (iii) we take into account the observational errors in z and A, that tend to overestimate the merger fraction, by maximum likelihood techniques. We find: (i) our data allow for a robust merger fraction to be provided for a single redshift bin centered at z=0.6. (ii) Merger fractions have low values: f_m = 0.045 for M_B <= -20 galaxies, and f_m = 0.031 for M_Ks <= -23.5 galaxies. And, (iii) failure to address the effects of the observational errors leads to overestimating f_m by factors of 10%-60%. Combining our results with those on literature, and parameterizing the merger fraction evolution as f_m(z) = f_m(0)(1+z)^m, we obtain that m = 2.9 +- 0.8, and f_m(0) = 0.012 +- 0.004$. Assuming a Ks-band mass-to-light ratio not varying with luminosity, we infer that the merger rate of galaxies with stellar mass M >= 3.5x10^10 M_Sun is R_m = 1.6x10^-4 Mpc^-3 Gyr^-1. When we compare with previous studies at similar redshifts, we find that the merger rate decreases when mass increases.Comment: Accepted for publication in ApJ. 11 pages, 7 figures, 3 tables. Formatted with emulateap

Robot de campo para detectar enfermedades en cultivos hortícolas mediante imágenes multiespectrales

Se ha construido un robot eléctrico asistido por control remoto para inspeccionar cultivos hortícolas mediante teledetección, embarcando tres cámaras réflex (dos modificadas para NIR y BNDVI), una térmica, otra multiespectral (ocho bandas entre 550 y 850 nm) y otra hiperespectral (400-1000 nm). Las cámaras están colocadas mirando al suelo (plantas) y para controlar la iluminación se utilizan cuatro focos halógenos en la zona de inspección que ha sido protegida de la luz exterior con una lona. Las imágenes se han georeferenciado utilizado un receptor GNSS (resolución de 3 cm). Para controlar el avance del robot y sincronizar la adquisición de imágenes, se ha desarrollado una placa electrónica a medida utilizando un sensor inductivo acoplado a las ruedas del robot y un software a medida instalado en un computador industrial.Se han realizado inspecciones mensuales en dos parcelas experimentales de zanahorias en Villena (España) para detectar plantas asintomáticas infectadas por Candidatus Liberibacter solanacearum. Se han creado mapas del campo utilizando índices vegetativos a partir de los datos espectrales con resoluciones entre 1 y 2,5 mm por píxel. Durante el último ensayo, se etiquetaron 100 plantas que se recolectaron y analizaron utilizando PCR en tiempo real para comparar los resultados con el análisis de las imágenes

The minor role of gas-rich major mergers in the rise of intermediate-mass early types at z <~ 1

We study the evolution of galaxy structure since z ~ 1 to the present. From a GOODS-S multi-band catalog we define (blue) luminosity- and mass-weighted samples, limited by M_B = 10^10 M_Sun, comprising 1122 and 987 galaxies, respectively. We extract early-type (E/S0/Sa) and late-type (Sb-Irr) subsamples by their position in the concentration-asymmetry plane, in which galaxies exhibit a clear bimodality. We find that the early-type fraction, f_ET, rises with cosmic time, with a corresponding decrease in the late-type fraction, f_LT, in both luminosity- and mass-selected samples. However, the evolution of the comoving number density is very different: the decrease in the total number density of M_B <= -20 galaxies since z = 1 is due to the decrease in the late-type population, which accounts for ~75% of the total star-formation rate in the range under study, while the increase in the total number density of M_star >= 10^10 M_Sun galaxies in the same redshift range is due to the evolution of early types. This suggests that we need a structural transformation between late-type galaxies that form stars actively and early-type galaxies in which the stellar mass is located. Comparing the observed evolution with the gas-rich major merger rate in GOODS-S, we infer that only ~20% of the new early-type galaxies with M_star >= 10^10 M_Sun appeared since z ~ 1 can be explained by this kind of mergers, suggesting that minor mergers and secular processes may be the driving mechanisms of the structural evolution of intermediate-mass (M_star ~ 4x10^10 M_Sun) galaxies since z ~ 1.Comment: Matches published version in ApJ. 16 pages, 4 figures, 5 table

Comparative conformational analysis of peptides based on the two Cα-tetrasubstituted, Cβ-branched, chiral α-amino acids (αMe)Dip and (αMe)Val

For the first time a number of terminally protected model peptides (to the pentamer level) of the sterically demanding α-amino acid Cα-methyl,Cα-diphenylmethylglycine, (αMe)Dip, in combination with either Ala or Gly residues, have been synthesized (by solution methods) and fully characterized. In a parallel synthesis the corresponding peptides based on the related α-amino acid Cα-methyl,Cα-isopropylglycine, (αMe)Val, have also been prepared. The results of a comparative conformational analysis, performed by using FTIR absorption, 1H NMR, and X-ray diffraction techniques, favour the conclusion that, in contrast to the potent β-turn and 310-helix promoter (αMe)Val, (αMe)Dip may induce either a folded or a fully extended conformation. These findings indicate that, despite the common Cα-methylated and Cβ-branched features, (αMe)Dip and (αMe)Val are characterized by partially divergent conformational bias.The Padova authors gratefully acknowledge M.U.R.S.T., the Ministry of University and Scientific and Technological Research, and the National Council of Research (C.N.R.) of Italy for their continuous support of this research. The Zaragoza and Padova authors are also grateful to the Spain-Italy exchange program “Accion Integrada” HI 97-20/“Azioni Integrate” 1997/1999.Peer reviewe

Dietary administration of D-chiro-inositol attenuates sex-specific metabolic imbalances in the 5xFAD mouse model of Alzheimer’s disease

Increasing evidence shows that hypothalamic dysfunction, insulin resistance, and weight loss precede and progress along with the cognitive decline in sporadic Alzheimer’s Disease (AD) with sex differences. This study aimed to determine the effect of oral dietary administration of D-Chiro-inositol (DCI), an inositol used against insulin resistance associated with polycystic ovary, on the occurrence of metabolic disorders in the transgenic 5xFAD mouse model of AD (FAD: Family Alzheimer's Disease). DCI was administered from 6 to 10 months of age to male and female 5xFAD mice and control (non-Tg) littermates. Energy balance and multiple metabolic and inflammatory parameters in the hypothalamus, liver and plasma were evaluated to assess the central and peripheral effects of DCI. Results indicated that weight loss and reduced food intake in 5xFAD mice were associated with decreased neuropeptides controlling food intake and the appearance of a pro-inflammatory state in the hypothalamus. Oral administration of DCI partially restored energy balance and hypothalamic parameters, highlighting an increased expression of Npy and Agrp and female-specific downregulation of Gfap and Igf1. DCI also partially normalized impaired insulin signaling and circulating insulin, GLP-1, and GIP deficiencies in 5xFAD mice. Principal component analysis of metabolic parameters indicated the presence of a female-specific fatty liver in 5xFAD mice: DCI administration reversed hepatic fat accumulation, β-oxidation, inflammation and increased GOT and GPT levels. Our study depicts that metabolic impairment along with the cognitive decline in a mouse model of AD, which is exacerbated in females, can be ameliorated by oral supplementation with insulin-sensitizing DCI.This research was funded by the European Regional Development Funds-European Union (ERDF-EU) and Fatzheimer project EULAC-HEALTH H2020, grant number EU-LACH16/T010131; Ministerio de Economía, Industria y Competitividad, Gobierno de España, grant number RTC-2016-4983-1; EU-ERDF and Instituto de Salud Carlos III (ISCIII), grant numbers PI19/01577 and PI19/00343; Ministerio de Sanidad, Delegación de Gobierno para el Plan Nacional sobre Drogas, grant numbers 2019/040 and 2020/048; Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, grant number P18-TP-5194, INSERM (Institut National de la Santé et de la Recherche Médicale), Nouvelle Aquitaine Region and ANR (grant numbers ANR-18-CE14-0029 MitObesity, Labex BRAIN ANR-10-LABX-43, ANR-10-EQX-008-1 OPTOPATH, ANR-17-CE14-0007 BABrain, ANR-21-CE14-0018-01_StriaPOM to D.C.). A.J.L.-G. (IFI18/00042) holds an “iPFIS” predoctoral contract from the National System of Health, EU-ERDF-ISCIII. B.P.S (IFI21/00024) holds an “iPFIS” predoctoral contract from the National System of Health, EU-ERDF-ISCIII. P.R. (CP19/00068) holds a ‘’Miguel Servet I” research contract from the National System of Health, EU-ERDF-ISCIII. D.M-V. (FI20/00227) holds a “PFIS” pre-doctoral contract from the National System of Health, EU-ERDF-ISCIII. The microscopy for IBA1 and GFAP immunofluorescence was done in the Bordeaux Imaging Center, a service unit of the CNRS-INSERM and Bordeaux University, member of the national infrastructure France BioImaging supported by the LabEX BRAIN and ANR-10-INBS-04. Partial funding for open access charge: Universidad de Málaga

J-PLUS : a catalogue of globular cluster candidates around the M 81/M 82/NGC 3077 triplet of galaxies

Globular clusters (GCs) are proxies of the formation assemblies of their host galaxies. However, few studies exist targeting GC systems of spiral galaxies up to several effective radii. Through 12-band Javalambre Photometric Local Universe Survey (J-PLUS) imaging, we study the point sources around the M 81/M 82/NGC 3077 triplet in search of new GC candidates. We develop a tailored classification scheme to search for GC candidates based on their similarity to known GCs via a principal component analysis projection. Our method accounts for missing data and photometric errors. We report 642 new GC candidates in a region of 3.5 deg2 around the triplet, ranked according to their Gaia astrometric proper motions when available. We find tantalizing evidence for an overdensity of GC candidate sources forming a bridge connecting M 81 and M 82. Finally, the spatial distribution of the GC candidates (g − i) colours is consistent with halo/intra-cluster GCs, i.e. it gets bluer as they get further from the closest galaxy in the field. We further employ a regression-tree-based model to estimate the metallicity distribution of the GC candidates based on their J-PLUS bands. The metallicity distribution of the sample candidates is broad and displays a bump towards the metal-rich end. Our list increases the population of GC candidates around the triplet by threefold, stresses the usefulness of multiband surveys in finding these objects, and provides a testbed for further studies analysing their spatial distribution around nearby (spirals) galaxies