A search for TeV gamma-ray emission from SNRs, pulsars and unidentified GeV sources in the Galactic plane in the longitude range between -2 deg and 85 deg

Using the HEGRA system of imaging atmospheric Cherenkov telescopes, one quarter of the Galactic plane (-2 deg < l < 85 deg) was surveyed for TeV gamma-ray emission from point sources and moderately extended sources (diameter <= 0.8 deg). The region covered includes 86 known pulsars (PSR), 63 known supernova remnants (SNR) and nine GeV sources, representing a significant fraction of the known populations. No evidence for emission of TeV gamma radiation was detected, and upper limits range from 0.15 Crab units up to several Crab units, depending on the observation time and zenith angles covered. The ensemble sums over selected SNR and pulsar subsamples and over the GeV-sources yield no indication for emission from these potential sources. The upper limit for the SNR population is at the level of 6.7% of the Crab flux and for the pulsar ensemble at the level of 3.6% of the Crab flux.Comment: 10 pages, 5 figures, 4 tables, accepted for publication in A&

Distribution of the Octopamine Receptor AmOA1 in the Honey Bee Brain

Octopamine plays an important role in many behaviors in invertebrates. It acts via binding to G protein coupled receptors located on the plasma membrane of responsive cells. Several distinct subtypes of octopamine receptors have been found in invertebrates, yet little is known about the expression pattern of these different receptor subtypes and how each subtype may contribute to different behaviors. One honey bee (Apis mellifera) octopamine receptor, AmOA1, was recently cloned and characterized. Here we continue to characterize the AmOA1 receptor by investigating its distribution in the honey bee brain. We used two independent antibodies produced against two distinct peptides in the carboxyl-terminus to study the distribution of the AmOA1 receptor in the honey bee brain. We found that both anti-AmOA1 antibodies revealed labeling of cell body clusters throughout the brain and within the following brain neuropils: the antennal lobes; the calyces, pedunculus, vertical (alpha, gamma) and medial (beta) lobes of the mushroom body; the optic lobes; the subesophageal ganglion; and the central complex. Double immunofluorescence staining using anti-GABA and anti-AmOA1 receptor antibodies revealed that a population of inhibitory GABAergic local interneurons in the antennal lobes express the AmOA1 receptor in the cell bodies, axons and their endings in the glomeruli. In the mushroom bodies, AmOA1 receptors are expressed in a subpopulation of inhibitory GABAergic feedback neurons that ends in the visual (outer half of basal ring and collar regions) and olfactory (lip and inner basal ring region) calyx neuropils, as well as in the collar and lip zones of the vertical and medial lobes. The data suggest that one effect of octopamine via AmOA1 in the antennal lobe and mushroom body is to modulate inhibitory neurons

H.E.S.S. follow-up observations of GRB221009A

GRB221009A is the brightest gamma-ray burst ever detected. To probe the very-high-energy (VHE, $>$\!100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observations 53 hours after the triggering event, when the brightness of the moonlight no longer precluded observations. We derive differential and integral upper limits using H.E.S.S. data from the third, fourth, and ninth nights after the initial GRB detection, after applying atmospheric corrections. The combined observations yield an integral energy flux upper limit of $\Phi_\mathrm{UL}^{95\%} = 9.7 \times 10^{-12}~\mathrm{erg\,cm^{-2}\,s^{-1}}$ above $E_\mathrm{thr} = 650$ GeV. The constraints derived from the H.E.S.S. observations complement the available multiwavelength data. The radio to X-ray data are consistent with synchrotron emission from a single electron population, with the peak in the SED occurring above the X-ray band. Compared to the VHE-bright GRB190829A, the upper limits for GRB221009A imply a smaller gamma-ray to X-ray flux ratio in the afterglow. Even in the absence of a detection, the H.E.S.S. upper limits thus contribute to the multiwavelength picture of GRB221009A, effectively ruling out an IC dominated scenario.Comment: 10 pages, 4 figures. Accepted for publication in APJL. Corresponding authors: J. Damascene Mbarubucyeye, H. Ashkar, S. J. Zhu, B. Reville, F. Sch\"ussle

No ‘bypass’ in adult ruminants: Passage of fluid ingested vs. fluid inserted into the rumen in fistulated muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose (Alces alces)

In young ruminants, the reticular groove ensures that ingested milk is channelled past the forestomach to avoid malfermentation. It has been speculated that some adult wild ruminants, in particular browsing species, maintain a functional oesophageal (reticular) groove, that soluble nutrients can thus bypass the rumen, and that thus the energetic gain from the diet can be increased. We inserted a fluid marker (Co-EDTA) via cannula into the rumen and simultaneously fed a diet that contained a second fluid marker (Sm-EDTA), and analysed the faecal marker excretion patterns, in muskoxen (Ovibos moschatus, n=4 in two experiments each), reindeer (Rangifer tarandus, n=4 in a total of six experiments) and moose (Alces alces, n=1 in one experiment). In no case was the orally fed marker excreted dinstinctively earlier than the marker inserted into the rumen, which indicates that substantial bypass did not occur in these animals. However, differences between the three species in the excretion of the two markers from the rumen are consistent with hypothetical differences in the stratification of rumen contents. We suggest that effects previously ascribed to a “rumen bypass” in wild ruminants most likely reflect differences in the passage from the rumen