Cholinergic signals preserve haematopoietic stem cell quiescence during regenerative haematopoiesis.

The sympathetic nervous system has been evolutionary selected to respond to stress and activates haematopoietic stem cells via noradrenergic signals. However, the pathways preserving haematopoietic stem cell quiescence and maintenance under proliferative stress remain largely unknown. Here we found that cholinergic signals preserve haematopoietic stem cell quiescence in bone-associated (endosteal) bone marrow niches. Bone marrow cholinergic neural signals increase during stress haematopoiesis and are amplified through cholinergic osteoprogenitors. Lack of cholinergic innervation impairs balanced responses to chemotherapy or irradiation and reduces haematopoietic stem cell quiescence and self-renewal. Cholinergic signals activate α7 nicotinic receptor in bone marrow mesenchymal stromal cells leading to increased CXCL12 expression and haematopoietic stem cell quiescence. Consequently, nicotine exposure increases endosteal haematopoietic stem cell quiescence in vivo and impairs hematopoietic regeneration after haematopoietic stem cell transplantation in mice. In humans, smoking history is associated with delayed normalisation of platelet counts after allogeneic haematopoietic stem cell transplantation. These results suggest that cholinergic signals preserve stem cell quiescence under proliferative stress

Raza ovina Ansotana II. Caracteres cualitativos externos

La raza ovina Ansotana es originaria del Noroeste de la provincia de Huesca y del Norte de la de Zaragoza. Es una raza considerada en peligro de extinción con un censo de 3400 animales. Se han obtenido un total de 31 variables cualitativas correspondientes a las regiones de la cabeza, tronco, mamas y extremidades, así como caracteres de índole faneróptica relativos al color de la capa y piel. Los ani- males controlados han sido 87 reproductores, 77 hembras y 10 machos, localizados en un total de 6 explotaciones. La instauración de un plan de conservación y fomento pasa, previamente, por una ca- racterización que analice el grado de diversidad inicial. La raza Asotana se encuentra en un estado de conservación complicado debido a su reducido censo, necesitando seguir aplicando los criterios de se- lección actual para que no se produzcan grandes variaciones con respecto al Estándar racial actual.The Ansotana breed is original from N.W province of Huesca and N. of Zaragoza.The current popula- tion of this endangered breed is 3400 animals. Thirty one qualitative characters were obtained from the head, body, mammals and limbs regions, as well as to faneroptic characters relatives to the coat colour and skin. Eighty-seven animals were controlled, 77 adult females and 10 adult males on 6 dif- ferent flocks. The establishment of a conservation planning passes previously by a characterisation that analyses the departure diversity degree

Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution

We present C and O abundances in the Magellanic Clouds derived from deep spectra of HII regions. The data have been taken with the Ultraviolet-Visual Echelle Spectrograph at the 8.2-m VLT. The sample comprises 5 HII regions in the Large Magellanic Cloud (LMC) and 4 in the Small Magellanic Cloud (SMC). We measure pure recombination lines (RLs) of CII and OII in all the objects, permitting to derive the abundance discrepancy factors (ADFs) for O^2+, as well as their O/H, C/H and C/O ratios. We compare the ADFs with those of other HII regions in different galaxies. The results suggest a possible metallicity dependence of the ADF for the low-metallicity objects, but more uncertain for high-metallicity objects. We compare nebular and B-type stellar abundances and we find that the stellar abundances agree better with the nebular ones derived from collisionally excited lines (CELs). Comparing these results with other galaxies we observe that stellar abundances seem to agree better with the nebular ones derived from CELs in low-metallicity environments and from RLs in high-metallicity environments. The C/H, O/H and C/O ratios show almost flat radial gradients, in contrast with the spiral galaxies where such gradients are negative. We explore the chemical evolution analysing C/O vs. O/H and comparing with the results of HII regions in other galaxies. The LMC seems to show a similar chemical evolution to the external zones of small spiral galaxies and the SMC behaves as a typical star-forming dwarf galaxy.Comment: Accepted for publication in MNRAS, 17 pages, 11 figures, 8 table

Ansotana sheep breed I. Morphostructural characters

La raza ovina Ansotana es originaria del Noroeste de la provincia de Huesca y Norte de la de Zaragoza. En la actualidad cuenta con un censo de unos 3.400 animales inscritos en el Libro Genealógico. Se han obtenido 17 medidas zoométricas en 77 hembras y 10 machos adultos procedentes de 6 rebaños que permiten deducir que es una raza de proporciones brevilíneas, con una clara tendencia de la me- socefalia a la dolicocefalía, más acusada en las hembras, y con predominio de extremidades muy cortas en relación a la altura del animal. En general, tanto los machos como las hembras presentan una mediana homogeneidad morfoestructural en casi todas las variables. En cuanto al grado de armonía, en las hembras puede catalogarse como medio y en los machos se observa baja armonía, lo que indica que sería importante aunar los criterios de selección.The Ansotana breed is original from N.W province of Huesca and N. of Zaragoza. The current popula- tion is 3.400 animals, which are entered in the genealogical register. Seventeen zoometrical measure- ments were obtained from 77 ewes and 10 rams from 6 different flocks. The results show that this breed has brevilineous proportions and tends to dolicocefalous, especially females, with predomi- nance of short limbs respect to the height. Overall, females and males show a medium level of homo- geneity in the majority of morphometric variables. The degree of harmony is medium in ewes and low in the rams, suggesting that all selection criteria should be combined in the same morphostructural model

Dual cholinergic signals regulate daily migration of hematopoietic stem cells and leukocytes.

Hematopoietic stem and progenitor cells (HSPCs) and leukocytes circulate between the bone marrow (BM) and peripheral blood following circadian oscillations. Autonomic sympathetic noradrenergic signals have been shown to regulate HSPC and leukocyte trafficking, but the role of the cholinergic branch has remained unexplored. We have investigated the role of the cholinergic nervous system in the regulation of day/night traffic of HSPCs and leukocytes in mice. We show here that the autonomic cholinergic nervous system (including parasympathetic and sympathetic) dually regulates daily migration of HSPCs and leukocytes. At night, central parasympathetic cholinergic signals dampen sympathetic noradrenergic tone and decrease BM egress of HSPCs and leukocytes. However, during the daytime, derepressed sympathetic noradrenergic activity causes predominant BM egress of HSPCs and leukocytes via β3-adrenergic receptor. This egress is locally supported by light-triggered sympathetic cholinergic activity, which inhibits BM vascular cell adhesion and homing. In summary, central (parasympathetic) and local (sympathetic) cholinergic signals regulate day/night oscillations of circulating HSPCs and leukocytes. This study shows how both branches of the autonomic nervous system cooperate to orchestrate daily traffic of HSPCs and leukocytes

Physical Conditions in Barnard's Loop, Components of the Orion-Eridanus Bubble, and Implications for the WIM Component of the ISM

We have supplemented existing spectra of Barnard's Loop with high accuracy spectrophotometry of one new position. Cloudy photoionization models were calculated for a variety of ionization parameters and stellar temperatures and compared with the observations. After testing the procedure with recent observations of M43, we establish that Barnard's Loop is photoionized by four candidate ionizing stars, but agreement between the models and observations is only possible if Barnard's Loop is enhanced in heavy elements by about a factor of 1.4. Barnard's Loop is very similar in properties to the brightest components of the Orion-Eridanus Bubble and the Warm Ionized Medium (WIM). We are able to establish models that bound the range populated in low-ionization color-color diagrams (I([SII])/I(H{\alpha}) versus I([NII])/I(H{\alpha})) using only a limited range of ionization parameters and stellar temperatures. Previously established variations in the relative abundance of heavy elements render uncertain the most common method of determining electron temperatures for components of the Orion-Eridanus Bubble and the WIM based on only the I([NII])/I(H{\alpha}) ratio, although we confirm that the lowest surface brightness components of the WIM are on average of higher electron temperature. The electron temperatures for a few high surface brightness WIM components determined by direct methods are comparable to those of classical bright H II regions. In contrast, the low surface brightness HII regions studied by the Wisconsin H{\alpha} Mapper are of lower temperatures than the classical bright HII regions

Updated aspects of safety regulations for biomedical applications of aerogel compounds-compendia-like evaluation

Aerogels have recently started to be considered as “advanced materials”; therefore, as a general consideration, aerogels’ toxicity testing should focus on their functionality which resides in their nanoscale open internal porosity. To assess the hazards of organic aerogels, testing at three levels may characterize their biophysical, in vitro and in vivo toxicity, defining distinct categories of aerogels. At the first level of testing, their abiotic characteristics are investigated, and the best aerogel(s) is forwarded to be tested at level 2, wherein in vitro methodologies may mainly evaluate the aerogels’ cellular behavior. Within level 2 of testing, the main characteristics of toxicity are investigated and the selected aerogels are introduced to in vivo animal models at level 3. In the animal model testing, target organs are investigated along with systemic parameters of toxicity. Some study cases are presented for organic or anorganic aerogels. Within this tiered workflow, aerogels-based materials can be tested in terms of human health hazard.European Cooperation in Science and Technology | Ref. CA18125Xunta de Galicia | Ref. ED431C 2020/17Agencia Estatal de Investigación | Ref. PID2020-120010RB-I0