Molecular line survey of Sagittarius B2(M) from 330 to 355 GHz and comparison with Sagittarius B2(N)

We have surveyed molecular line emission from Sgr B2 over the range from 330 to 355 GHz at the position designated Sgr B2(M). This position is prominent in millimeter continuum maps of the region and is associated with a compact H II region, a hot NH_3 core, and sources of H_2O and OH maser emission. We have also obtained observations contrasting the submillimeter molecular emission from Sgr B2(M) and Sgr B2(N), an additional center of activity thought to be a dense protostellar core. The picture of the interstellar chemistry of these regions which we derive is substantially different from that determined from previous observations at lower frequencies and with lower spatial resolution. In particular, molecules such as SO_2 and CH_3OH dominate the submillimeter spectrum to a much greater extent than they do the low-frequency observations. Much of this difference is due to the higher spatial resolution of the submillimeter observations, which makes them much more sensitive to emission from compact, dense cores. The millimeter data were most effective at sampling material in the surrounding lower density regions. The chemistry of the core sources in Sgr B2 appears similar to that of other dense cores, such as the core of the Orion molecular cloud. The spectral differences between Sgr B2(M) and Sgr B2(N) primarily relate to differences in excitation and column density. For most molecular species the northern source (N) has a column density significantly higher than that found in the middle source (M), often by a factor of about 5. The principal exceptions are the species SO and SO_2 which seem to be substantially more abundant in the middle source. Generally excitation seems to be higher in the northern source, suggesting a somewhat higher density core, although there are some departures indicating that the excitation situation is more complicated. High optical depths in many of the submillimeter transitions systematically bias the interpretation of both column densities and excitation. Many of the millimeter lines may also have high optical depths, particularly those lines arising from the compact core sources

Foxc1 is required by pericytes during fetal brain angiogenesis

Summary Brain pericytes play a critical role in blood vessel stability and blood–brain barrier maturation. Despite this, how brain pericytes function in these different capacities is only beginning to be understood. Here we show that the forkhead transcription factor Foxc1 is expressed by brain pericytes during development and is critical for pericyte regulation of vascular development in the fetal brain. Conditional deletion of Foxc1 from pericytes and vascular smooth muscle cells leads to late-gestation cerebral micro-hemorrhages as well as pericyte and endothelial cell hyperplasia due to increased proliferation of both cell types. Conditional Foxc1 mutants do not have widespread defects in BBB maturation, though focal breakdown of BBB integrity is observed in large, dysplastic vessels. qPCR profiling of brain microvessels isolated from conditional mutants showed alterations in pericyte-expressed proteoglycans while other genes previously implicated in pericyte–endothelial cell interactions were unchanged. Collectively these data point towards an important role for Foxc1 in certain brain pericyte functions (e.g. vessel morphogenesis) but not others (e.g. barriergenesis)

Rapport III.4. Développement des équipements hydroagricoles et estimation prévisionnelle des besoins en eau d’irrigation dans le Bassin de la Garonne

A set of general investigations on hydroagricultural development in the main valleys of the Garonne river basin have been carried out for the French Ministry of Agriculture during the last few years. In this paper, factors in these investigations connected with the forecasting of irrigation water requirements are discussed, with particular emphasis on the methods applied. The paper is in three parts, as follows : 1. A general evaluation of potential requirements. 2. Particulars of flows required. 3. An attempt to forecast the trend of future demand. The general evaluation of potential requirements is based on a soil and climate study and allows for the probable frequency at which the requirements will arise. The particulars of the flows required to meet this demand emerge in a study of development schemes for potentially irrigable areas. The trend of future demand is uncertain and difficult to predict, depending as it does on a complex set of decisions, but generally speaking it can be linked with the socio-economic development of farming as a whole. An attempt has been made to establish a means of forecasting the latter development, so as to facilitate further progress in evaluating future demand and programming investment.Au cours des dernières années, le Ministère de l’Agriculture a fait procéder, dans le Bassin de la Garonne, à un ensemble d’études générales relatives aux aménagements hydroagricoles des vallées principales. La communication ci-dessous expose, en insistant sur les méthodes utilisées, ce qui, dans ces études, se rapporte à l’estimation prévisionnelle des besoins en eau d’irrigation. Elle est divisée en trois parties : — évaluation générale des besoins potentiels ; — caractéristiques des prélèvements ; — essai de prévision d’une évolution des besoins dans le temps. L’évaluation générale des besoins potentiels est basée sur l’étude des sols et du climat. Elle tient compte de la fréquence probable d’apparition de ces besoins. Les caractéristiques des prélèvements correspondant à ces besoins apparaissent lors de l’étude des schémas d’aménagement des zones dont l’irrigation peut être envisagée. L’évolution des besoins dans le temps, qui est liée à un ensemble complexe de décisions, est incertaine et reste difficile à prévoir. Elle peut être rattachée, d’une manière globale, au développement socio-économique de l’agriculture. Une tentative a été faite pour mettre sur pied un instrument de prévision de ce développement, qui puisse aider au progrès de l’évaluation des besoins, et de la programmation des investissements.Kreitmann H., Jaminet P., Boissezon J. de. Rapport III.4. Développement des équipements hydroagricoles et estimation prévisionnelle des besoins en eau d’irrigation dans le Bassin de la Garonne. In: Utilisation des ressources en eau d'un bassin dans le cadre de l'aménagement du territoire. Compte rendu des onzièmes journées de l'hydraulique; Paris, 22-24 septembre 1970. Tome 1, 1971