Non-specific inhibition of dipeptidyl peptidases 8/9 by dipeptidyl peptidase 4 inhibitors negatively affects mesenchymal stem cell differentiation

DPP4 may play a relevant role in MSC differentiation into osteoblasts or adipocytes. Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4i), such as sitagliptin and vildagliptin, are used as antidiabetic drugs. However, vildagliptin is not a specific DPP4i and also inhibits DPP8/9, which is involved in energy metabolism and immune regulation. The aim of this study is to evaluate how sitagliptin, vildagliptin or 1G244 (a DPP8/9 specific inhibitor) may influence cell viability, as well as osteogenic and adipogenic differentiation in human mesenchymal stem cells (MSC). Viability, apoptosis, osteoblastogenesis and adipogenesis markers, as well as protein synthesis of β-catenin, were studied in MSC cultures induced to differentiate into osteoblasts or adipocytes in the presence or absence of sitagliptin, vildagliptin or 1G244. The two tested DPP4i did not affect MSC viability, but 1G244 significantly decreased it in MSC and osteoblast-induced cells. Additionally, 1G244 and vildagliptin inhibited osteogenesis and adipogenesis, unlike sitagliptin. Therefore, inhibition of DPP4 did not affect MSC viability and differentiation, whereas inhibition of DPP8/9 negatively affected MSC. To the best of our knowledge, these results show for the first time that DPP8/9 have an important role in the viability and differentiation of human MSC. This data can be considered for human clinical use of drugs affecting DPP8/9 activity

Nest-dwelling ectoparasites reduce begging effort in Pied Flycatcher Ficedula hypoleuca nestlings

Parasitized nestlings might be expected to increase begging effort to obtain additional resources to compensate for those sequestered by their parasites. However, begging is costly and chicks harbouring parasites may find it more difficult to attain high begging levels. Consequently, we predicted that, for the same level of nutritional need, nestlings that are parasitized will invest less in begging than those that are not parasitized. We tested this prediction by measuring begging in Pied Flycatcher Ficedula hypoleuca nestlings parasitized with haematophagous mites Dermanyssus gallinoides and Dermanyssus gallinae and blowfly larvae Protocalliphora azurea, and subjected to different levels of food deprivation in order to control for short-term nutritional need. Nestlings from nests with ectoparasites spent less time begging than those from nests without parasites, especially when very hungry, although there was no association with latency to beg or begging intensity. Our results suggest that time invested in begging may indicate not only the level of need, but also nestling parasitism status.Peer Reviewe

Crypsis Decreases with Elevation in a Lizard

Predation usually selects for visual crypsis, the colour matching between an animal and its background. Geographic co-variation between animal and background colourations is well known, but how crypsis varies along elevational gradients remains unknown. We predict that dorsal colouration in the lizard Psammodromus algirus should covary with the colour of bare soil—where this lizard is mainly found—along a 2200 m elevational gradient in Sierra Nevada (SE Spain). Moreover, we predict that crypsis should decrease with elevation for two reasons: (1) Predation pressure typically decreases with elevation, and (2) at high elevation, dorsal colouration is under conflicting selection for both crypsis and thermoregulation. By means of standardised photographies of the substratum and colourimetric measurements of lizard dorsal skin, we tested the colour matching between lizard dorsum and background. We found that, along the gradient, lizard dorsal colouration covaried with the colouration of bare soil, but not with other background elements where the lizard is rarely detected. Moreover, supporting our prediction, the degree of crypsis against bare soil decreased with elevation. Hence, our findings suggest local adaptation for crypsis in this lizard along an elevational gradient, but this local adaptation would be hindered at high elevations.This study has been economically supported by the Ministerio de Ciencia e Innovación (project CGL2009-13185)

Clinical potential of mesenchymal stem cell-derived exosomes in bone regeneration

Bone metabolism is regulated by osteoblasts, osteoclasts, osteocytes, and stem cells. Pathologies such as osteoporosis, osteoarthritis, osteonecrosis, and traumatic fractures require effective treatments that favor bone formation and regeneration. Among these, cell therapy based on mesenchymal stem cells (MSC) has been proposed. MSC are osteoprogenitors, but their regenerative activity depends in part on their paracrine properties. These are mainly mediated by extracellular vesicle (EV) secretion. EV modulates regenerative processes such as inflammation, angiogenesis, cell proliferation, migration, and differentiation. Thus, MSC-EV are currently an important tool for the development of cell-free therapies in regenerative medicine. This review describes the current knowledge of the effects of MSC-EV in the different phases of bone regeneration. MSC-EV has been used by intravenous injection, directly or in combination with different types of biomaterials, in preclinical models of bone diseases. They have shown great clinical potential in regenerative medicine applied to bone. These findings should be confirmed through standardization of protocols, a better understanding of the mechanisms of action, and appropriate clinical trials. All that will allow the translation of such cell-free therapy to human clinic applications

Synthesis and characterization of nanocrystalline cellulose derived from Pineapple peel residues

Pineapple peel biomass was used as raw material for nanocellulose extraction. The raw material is a residue from the Costa Rican fruit industry. The nanocellulose was obtained by a two-step hydrolysis process. Firstly, the cellulose was hydrolyzed with HCl to obtain microcrystalline cellulose. In the second step, the hydrolysis was carried out using H2SO4 to obtain smaller fragments and decrease the lignin content. A time-dependent study was carried out to determine the particle size decrease depending on the contact time with the H2SO4. The chemical, thermal and morphological properties were analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), zeta potential, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The nanofiber-like cellulose was obtained after 60 minutes of exposure to 65 wt% H2SO4

Distribución espacial de la fructificación del hongo ECM comestible Amanita ponderosa Malençon & R. Heim durante seis años consecutivos en un encinar adehesado de la Sierra de Aracena (Huelva)

Number and location of Amanita ponderosa Malençon & R. Heim sporocarps was followed through six years in a 3 ha holm-oak forest located in the Sierra de Aracena y Picos de Aroche Natural Park (Huelva), at the Southwest of Spain. The data indicated that patches of sporocarp production showed a very similar shape each year, but some spots showed differences seeming crop alternance or mast years. This species only fructifies in spring, being the fruiting period from 6 to 8 weeks, what coincides with the increasing of air-temperature from mid February to April. Differences in fruiting period length and total sporocarp production are related to rainfall and temperature. Results suggest that rainfalls at the end of summer and early autumn are crucial for the next spring fruiting, but rainfalls during fruiting period seem to have less influence in sporocarp production. During the sporocarp production period, it was related to soil temperature.Se ha estudiado durante seis años consecutivos el número y la localización de los esporocarpos de Amanita ponderosa Malençon & R. Heim en una parcela de 3 ha ubicada en un encinar adehesado localizado en el Parque Natural «Sierra de Aracena y Picos de Aroche» (Huelva). Los datos indican que las áreas productoras de setas presentan un tamaño y una forma similares año tras año, aunque algunas zonas específicas muestran variaciones que sugieren la existencia de cierta alternancia o vecería. Esta especie fructifica solamente en primavera durante seis a ocho semanas, desde mediados de febrero hasta abril, cuando comienza a ascender la temperatura media tras el invierno. Las diferencias observadas en la duración del periodo de fructificación y la producción total de setas dependen fundamentalmente de las lluvias y la temperatura. Los resultados sugieren que las lluvias tempranas a finales de verano o principios de otoño son cruciales para la fructificación de la primavera siguiente, y que las lluvias caídas durante el periodo de fructificación tienen una menor influencia. Durante el periodo de fructificación, la producción es muy dependiente de la temperatura del suelo

Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC

We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy-estimation methods that utilize extensive air shower variables such as the core position, shower angle, and shower lateral energy distribution. In contrast, the previously published HAWC energy spectrum roughly estimated the shower energy with only the number of photomultipliers triggered. This new methodology yields a much improved energy resolution over the previous analysis and extends HAWC's ability to accurately measure gamma-ray energies well beyond 100 TeV. The energy spectrum of the Crab Nebula is well fit to a log parabola shape $\left(\frac{dN}{dE} = \phi_0 \left(E/\textrm{7 TeV}\right)^{-\alpha-\beta\ln\left(E/\textrm{7 TeV}\right)}\right)$ with emission up to at least 100 TeV. For the first estimator, a ground parameter that utilizes fits to the lateral distribution function to measure the charge density 40 meters from the shower axis, the best-fit values are $\phi_o$=(2.35$\pm$0.04$^{+0.20}_{-0.21}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.79$\pm$0.02$^{+0.01}_{-0.03}$, and $\beta$=0.10$\pm$0.01$^{+0.01}_{-0.03}$. For the second estimator, a neural network which uses the charge distribution in annuli around the core and other variables, these values are $\phi_o$=(2.31$\pm$0.02$^{+0.32}_{-0.17}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.73$\pm$0.02$^{+0.03}_{-0.02}$, and $\beta$=0.06$\pm$0.01$\pm$0.02. The first set of uncertainties are statistical; the second set are systematic. Both methods yield compatible results. These measurements are the highest-energy observation of a gamma-ray source to date.Comment: published in Ap

Multisystem inflammatory syndrome in children in western countries: decreasing incidence as the pandemic progresses? An observational multicenter international cross-sectional study

Multisystemic inflammatory syndrome temporally associated with SARS-CoV-2 infection in children (MIS-C) has been reported worldwide.1–7 The case definition of MIS-C has been estab- lished by different institutions and organizations such as the US Centers for Disease Control and Prevention (CDC) (May 14, 2020),8 the Royal College of Paediatrics and Child Health in the United Kingdom (RCPCH) (May 1, 2020)9,10 and the World Health Organi- zation (WHO) (May 15, 2020).1Postprint (published version

Water supply in artificial troughs: a strategy to mitigate the impacts of climate change in the Maya forest

ABSTRACT Objective: The objective of this work was to verify the functionality of the troughs based on the fauna record. Design/methodology/approach: About 70 artificial drinking troughs were installed, most of them inside the core zones of the CBR, and the remaining ones have been established in communities under the protection and supervision of beekeepers. A photo-trapping station was associated with each of the installed drinking troughs. Results: 91 species of wildlife have been identified that use the water from the artificial drinking troughs, of which 30 are mammals, 53 are birds, 5 are reptiles and 3 are amphibians. Endangered species such as the jaguar and the tapir are among the most frequent visitors to these sites, especially during the dry season. Study limitations/implications: The use of artificial water troughs is a good alternative to guarantee water availability in the Calakmul region. The high diversity of species that visit the drinking troughs constantly during the dry season makes evident the functionality of the water supply strategy in artificial drinking troughs. Findings/conclusions: The drinking troughs can be a tool used for various objectives in the region, it arose from the need to respond to an emergency climatological event such as drought, but has been adapting to the needs of the area and adapting to other activities, being considered a successful management strategy in the face of climate change.Objective: To verify the functionality of drinking troughs based on fauna record. Design/Methodology/Approach: Most of the approximately 70 artificial drinking troughs were installed inside the core zones of the Calakmul Biosphere Reserve (CBR). The remaining troughs were installed in communities and left under the protection and supervision of beekeepers. A camera-trap station was associated with each of the drinking troughs installed. Results: Ninety-one wildlife species that drink water from the artificial troughs have been identified, including 30 mammals, 53 birds, 5 reptiles, and three amphibians. Jaguars, tapirs, and other endangered species are some of the most frequent visitors to these sites, especially during the dry season. Study Limitations/Implications: The use of artificial water troughs is an adequate alternative to guarantee water availability in the Calakmul region. The high diversity of species that constantly visit the drinking troughs during the dry season makes evident the functionality of the water supply strategy with artificial drinking troughs. Findings/Conclusions: The drinking troughs can be a tool for various objectives in the region. It arose from the need to respond to emergency climatological events (i.e., droughts), but it has been adapted to the regional needs and other activities. It has been considered a successful management strategy in the face of climate change