Standard physics is capable to interpret ∼\sim18 TeV photons from GRB 221009A

It is reported that the Large High Altitude Air Shower Observatory (LHAASO) observed thousands of very-high-energy photons up to $\sim$18 TeV from GRB 221009A. We study the survival rate of these photons by considering the fact that they are absorbed by the extragalactic background light. By performing a set of $10^6$ Monte-Carlo simulations, we explore the parameter space allowed by current observations and find that the probability of predicting that LHAASO observes at least one photons of $\sim$18 TeV from GRB 221009A within 2000 seconds is 80\% and 25\% if assuming the spectral index of photon flux is $-2$ and $-3$, respectively. Hence, it is still possible for the standard physics to interpret the observation of LHAASO in the energy range of several TeV. Our research method can be straightforwardly generalized to study more data sets of LHAASO and other experiments in the future.Comment: 5 pages, 2 figure

Effects of different levels of protein-to-energy ratios on nutrient digestibility and digestive enzyme activity in Leiothrix luteal

Effects of different levels of protein-to-energy ratios (PER) on nutrient utilization, digestive organs index and digestive enzymes activities in Leiothrix luteal were investigated in this research. It was found that different PER feedstuff had no significant effects on the utilization of dry matter (DM), calcium (Ca) and total phosphorus (TP). With the improvement of the PER, average daily feed intake (ADFI) gradually increased, the apparent utilization rate of energy and fat gradually improved, while the apparent utilization rate of crude protein increased at first and then decreased. Development of digestive organs of L. luteal was affected by the level of dietary PER, with the increase in PER, the digestive organ indices of muscular stomach, duodenum, jejunoileum and rectum exhibited a downward trend, the main influencing factors were the level of metabolizable energy in diets. With the intestinal tract moving backward, the relative activity of proteases gradually reduced, manifesting as pancreas > duodenum > jejunoileum. The relative activity of carbohydrate digestion enzymes gradually increased as the intestinal tract moved backward. With the improvement of PER, the relative activity of lipase gradually decreased in pancreas, duodenum, and jejunoileum. L. luteal possessed a strong ability to digest crude fiber and total phosphorus; the reason might be closely related to the types and quantities of intestinal flora, which was affected by the feeding habits of this bird. By comprehensively considering the nutrient utilization, digestive organ indices and digestive enzymes activities, the formula of PER II was more appropriate for nutritional needs of L. luteal in captivity.Keywords: Leiothrix luteal, protein-to-energy ratios, nutrients, digestion and utilization, enzyme activitiesAfrican Journal of Biotechnology Vol. 12(15), pp. 1902-190

Statistical Analysis of Radio Propagation Channel in Ruins Environment

The cellphone based localization system for search and rescue in complex high density ruins has attracted a great interest in recent years, where the radio channel characteristics are critical for design and development of such a system. This paper presents a spatial smoothing estimation via rotational invariance technique (SS-ESPRIT) for radio channel characterization of high density ruins. The radio propagations at three typical mobile communication bands (0.9, 1.8, and 2 GHz) are investigated in two different scenarios. Channel parameters, such as arrival time, delays, and complex amplitudes, are statistically analyzed. Furthermore, a channel simulator is built based on these statistics. By comparison analysis of average excess delay and delay spread, the validation results show a good agreement between the measurements and channel modeling results

Distribution and Permeability of Capillaries at the Skin of the Conception Vessel and the Governor Vessel in Healthy Rabbits

ObjectiveTo investigate the distribution and permeability of blood vessels on the Conception Vessel and the Governor Vessel in the physiological state.MethodsEvans blue (EB) solution was injected into the marginal ear vein of healthy rabbits. Three hours after injection, the rabbits were sacrificed and the skin on the Conception Vessel and the Governor Vessel and the corresponding bilateral non-channels was collected. EB was extracted with 7:3 acetone: physiological saline, and the absorbance of EB at each skin tissue was measured with a spectrophotometer.ResultsThe A value of EB absorbance at the Conception Vessel on the abdominal skin was lower than that of the corresponding bilateral non-channels with a statistically significant difference (P<0.01). The A value of EB absorbance at the Governor Vessel on the back was higher than that of the corresponding bilateral non-channels (P<0.05). There was no statistical difference in the A value of EB absorbance between the bilateral non-channels of the abdomen and the back (P>0.05).ConclusionThere were differences in capillary distribution and permeability between the Conception Vessel, the Governor Vessel and the corresponding bilateral non-meridians