Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

Tiamulin and semduramicin: effects of simultaneous administration on performance and health of growing broiler chickens.

The pleuromutilin antibiotic tiamulin (TIA) is known to produce a variety of negative interactive effects when it is administered in combination with several anticoccidial ionophores. A 35-d growth study was performed in cages to evaluate the compatibility of TIA when it was administered concurrently with the poly-ether ionophore anticoccidial semduramicin (SEM). Tiamulin and SEM, both alone and in combination, were administered to 10 replicates of female broilers arranged in a completely randomized block design. Tiamulin was administered in drinking water (250 mg of TIA/kg of water) from d 15 through 19 of the study, whereas SEM was incorporated in feed (25 mg/kg) from placement to the conclusion of the test. Water consumption was determined during the period of concurrent administration of the drugs and weekly measurements of feed intake and bird performance were recorded. In addition, hematocrit, blood cell counts, serum protein, albumin, glucose, uric acid, electrolytes, and activities of several enzymes were determined from blood samples taken at d 35. Results indicated that simultaneous administration of TIA and SEM during the third week of the trial reduced water and feed intake resulting in a temporary growth depression. Feed efficiency was transiently affected during the period of coadministration. However, during the fourth week of the test, negative effects in body weight were not observed for any treatment and feed conversion improved for birds concurrently receiving TIA + SEM. By the termination of the experiment, no adverse effects were observed in final performance for any treatment. Histopathological and hematological parameters were unaffected by treatment at d 35 of the test. These results demonstrated that simultaneous administration of TIA and SEM produced only temporary impairments of water and feed consumption that transiently influenced performance. Neither mortality nor long-term effects on performance variables occurred in broilers.

Effect of feeding exercised horses on high-starch or high-fat diets for 390 days.

Our hypothesis was that, because horses have not evolved as fat eaters, there may be negative metabolic long-term effects of feeding a high fat diet. The objective of the present study was to identify these long-term effects and compare them with the effects of isoenergetic long-term high starch feeding. This randomised block study with 20 exercised horses looked at the effect of feeding either a high starch (HS) or a high fat (HF) diet type in 3 periods during stabling (Stable 1), pasture, and stabling (Stable 2) over 390 days. The horses received a HS or HF concentrate, straw, hay and 6 h pasture/day in the pasture period. HF horses gained weight (2% of initial bwt) and, therefore, fat intake was reduced (from 1.43 to 0.88 g/kg bwt/day). Blood plasma glucose, total protein, albumins, gamma-globulins, free fatty acids, phospholipids and cholesterol concentrations were higher but urea concentration was lower with HF compared to HS feeding (P<0.05). Plasma concentrations of triglycerides, bilirubin and pre-beta lipoproteins were unaffected by the diet type. There were period effects (P<0.05) for all variables except triglycerides and pre-beta lipoproteins. In contrast to HS, in HF the quotient alpha/beta lipoproteins rose (P<0.05) throughout the stable periods and decreased (P<0.05) during 'pasture'. Glutamic acid dehydrogenase, gamma-glutamyl transferase, alkaline phosphatase, aspartate aminotransferase, creatine kinase and lactate dehydrogenase activity in sera were within the normal range. In conclusion, on the precondition that substantial bodyweight changes were prevented, no apparent adverse effects of long-term high fat feeding were identified and there were no apparent disadvantages of feeding on high fat compared with high starch diets.

Effect of dietary beta-carotene on the early embryonic development and uterine fluid composition of gilts.

The role of beta-carotene in reproduction was investigated in gilts assigned to three dietary supplementations: VA (4000 IU vitamin A); VA + VA (4000 IU + 8300 IU); VA + BC (4000 IU + 100 mg beta-carotene) per kg diet for 14 weeks. Gilts were slaughtered at day 12 of gestation. In the VA + BC group, number of corpora lutea was lowest, but the number of embryos was greatest, resulting in a non-significant decreased prenatal mortality (p<0.07). The proportion of less developed spherical and tubular embryos compared with filamentous was greatest in the VA + BC group (p<0.01). No differences were observed for vitamin A and retinal binding protein (RBP) in the uterine fluid. When animals were grouped according to the development of blastocysts, vitamin A and RBP levels were higher in the VA + BC group with only filamentous embryos (p<0.01). This indicates that the supplementation of beta-carotene to gilts might affect embryonic losses possibly because of slower alterations in the uterine environment, resulting in a higher and less variable number of embryos, despite an apparently more heterogeneous development.

Effect of dietary beta-carotene on the accumulation of beta-carotene and vitamin A in plasma and tissues of gilts.

The absorption of beta-carotene in pigs is limited. Nevertheless beta-carotene might positively affect reproduction. In this study the absorption and tissue distribution of beta-carotene as well as its function as precursor of vitamin A was investigated in gilts that were fed according to one of three dietary treatments: VA (4000 IU vitamin A), VA + VA (4000 IU + 8300 IU) and VA + BC (4000 IU + 100 mg beta-carotene per kg diet) for 14 weeks. Only in the VA + BC group was beta-carotene detected in plasma (1-8 ng x mL(-1)), liver, adrenals and corpora lutea, indicating that pigs absorb intact beta-carotene at low rates. Liver levels of vitamin A were higher (P < 0.01) at comparable levels in the VA + VA and VA + BC group than in the VA group, indicating a conversion rate of beta-carotene to vitamin A of 40 to 1 on the basis of weight for beta-carotene at this level (100 mg x kg(-1)) in the diet. Higher levels of vitamin A in the uterus of the VA + BC group (P < 0.01) as well as the accumulation of beta-carotene in adrenals and corpora lutea might reflect some influence of beta-carotene on local vitamin A metabolism which might be of importance for reproductive performance in gilts.

[Criteria for the appointment for a full professorship in the course of history at the School of Veterinary Medicine of Dresden/Leipzig]. / Voraussetzungen für die Berufung zum Professor im Wandel der Geschichte der tierärztlichen Lehranstalt Dresden/Leipzig.

First the history of the appointment for a full professorship is described in the various stages of development of the School of Veterinary Medicine Dresden. Then the significance of the habilitation degree introduced in 1903 is discussed in terms of the development of the School of Veterinary Medicine Dresden and the Faculty of Veterinary Medicine of the University of Leipzig, respectively. Commentary follows on the current discussion about the discontinuation of further development of the habilitation and possible alternatives to it, the Ph.D. and the assistant professorship.

[The effect of very low and moderate fiber levels on metabolism in the cecum of growing rabbits]. / Der Einfluss von sehr niedrigen und mittleren Fasermengen auf den Stoffwechsel im Blinddarm des wachsenden Kaninchens.

Investigations with 15N'-labelled urea were carried out to find out the influence of the amount of fibre on the reflux of 15N' into the caecum to take part in the caecal metabolism. Two pelleted diets, containing 9.7% (group 1 with 23% oat hulls) and 2.2% (Group 2 without oat hulls) crude fibre, with urea with 60 atom% 15N-excess (15N) used as marker were given to three White New Zealand rabbits each group. Group 1 and 2 consumed 109 and 72 g fresh matter per rabbit and day, respectively. Daily 15N'-intake per rabbit was 307 mg in group 1 and 279 mg in group 2. Most of 15N' was eliminated directly via the urine. The daily faecal excretion in group 1 and 2 was 5.3 and 2.3 mg 15N', respectively. Only about 20 to 30% of 15N' and volatile fatty acids in the caecum and higher amounts of 15N' in muscles were found. The animals of this group consumed nearly the total amount of faeces by caecotrophy. Therefore 24 g of group 2 was still satisfying compared to 33 g live weight gain/rabbit and day of group 1. It is concluded that the animals of group 2 could compensate the low fibre level within a period of about 20 days by a more efficient utilization, the consumption of crude protein and starch being 18 and 12% lower than in group 1, respectively. Feed intake and health status were not evidently affected. The results are in contradiction to the common knowledge.

Plasma transport and tissue distribution of [14C] beta-carotene and [3H]retinol administered orally to pigs.

The absorption, plasma transport, and tissue distribution of beta-carotene and vitamin A were studied in pigs after the oral administration of radiolabeled beta-carotene and retinol. Plasma radioactivity as well as retinol and beta-carotene were measured over a 24-h period, after which the pigs were killed. Plasma radioactivity increased within 4 h and 5 h for beta-carotene and retinol, respectively. The administration of radiolabeled retinol resulted in highest levels in the liver (83016 +/- 17614 dpm/g of tissue), followed by the kidney (5598 +/- 1309 dpm/g), the duodenum (2783 +/- 300 dpm/g), the colon (835 +/- 117 dpm/g), and the lung (756 +/- 68 dpm/g). Twenty-four hours after beta-carotene administration, tissue radioactivity distribution showed highest accumulation in the lung (22772 +/- 11997 dpm/g) and the liver (2328 +/- 694 dpm/g). The identification of the radioactive component 14C in the lung and colon indicated that the radioactivity was associated with beta-carotene only. This indicates that pigs may absorb intact beta-carotene. In other tissues such as liver, kidney, and intestine, only retinol-associated radioactivity was found after saponification of retinyl esters. The physiological importance of the unique accumulation of beta-carotene in lung tissue remains speculative.

[The effect of vitamin C and zinc on the copper-induced increase of cadmium residues in swine]. / Der Einfluss von Vitamin C und Zink auf die durch Kupfer erhöte Rückstandsbildung von Cadmium beim Schwein.

In commercial pig fattening, copper is added to the feed in amounts that greatly exceed the requirements of the animals. On the one hand, this improves weight gain, but on the other, as we were able to recently prove, the retention of the heavy metal cadmium rises in the kidney, in the liver and in muscle. In a feeding experiment with female and male castrated piglets, we tried to counter the copper-induced rise in cadmium (175 mg Cu/kg feed) by adding zinc or vitamin C to the diet. While addition of 100 or 200 mg zinc per kg of diet had no influence, the addition of 1000 mg vitamin C reduced the elevated cadmium values in the kidneys and livers to values only determined with a low copper supplementation of 35 mg copper per kg of feed. This positive vitamin C effect not only occurs in cases of high copper supplementation (175 mg Cu/kg feed); when the pigs were given only 35 mg copper per kg of feed, vitamin C also reduced the cadmium content in the organs by 35 to 40%. This indicates that vitamin C improves the quality of food gained from animals for human consumption in both conditions.

Influence of subchronic exposure to low dietary deoxynivalenol, a trichothecene mycotoxin, on intestinal absorption of nutrients in mice.

During a 6-wk feeding trial, effects of low dietary deoxynivalenol (DON; 0, 0.1, 1 and 10 ppm) on food consumption and weight gain were investigated in male mice. Food intake was similar in all four dietary groups. Weight gain in the group receiving 10 ppm DON was significantly (P less than 0.01) reduced. At the end of the feeding period, test animals were sacrificed and absorption of water, D-glucose, L-leucine, L-tryptophan, 5-methyltetrahydrofolic acid and iron was measured in isolated perfused jejunal segments in vitro. No effects were observed on absorption of water, leucine, tryptophan and iron. However, at a dietary DON concentration of 10 ppm, a slightly but significantly (P less than 0.05) reduced transfer of glucose was measured. Furthermore, transfer as well as tissue accumulation of 5-methyltetrahydrofolic acid in the jejunal segment were both significantly decreased up to 50%. Heavy metal and trace element content was determined in liver, kidney and small intestine. Manganese and molybdenum content in liver tissue was reduced with a DON concentration of 10 ppm in the diet. The findings indicate that subchronic ingestion of DON, in concentrations occurring in contaminated food and feed, results in an impairment of intestinal transfer and uptake of nutrients such as glucose and 5-methyltetrahydrofolic acid.

[Comparison of the biological activity and stability of menadione and menadiol in male chickens]. / Vergleich der biologischen Aktivität und Stabilität von Menadion und Menadiol bei Hühnerküken.

A bioassay of vitamin K is described, based on the prothrombin clotting time of 3-week-old, vitamin-K-depleted, and cumatetralyl-sensitized male broiler chicks, using a homologous thrombokinase preparation. With this test it could be shown that the diacetate and dibutyrate esters of menadiol are vitamin-K-active. The bioactivity of menadione from these menadiolesters amounted to about 70% of the standard menadione from a coated menadione sodium bisulfite (Dohyfral). Menadiol seems to be temperature-resistant under such conditions, whereby two uncoated MSB preparations lost about 60% of their activity.

[Effect of purine-rich nutrients on weight gain, catabolites in blood plasma and the uric acid transport of erythrocytes--a model study in dogs]. / Einflüsse purinreicher Ernährung auf Gewichtsentwicklung, Kataboliten im Blutplasma und den Harnsäuretransport von Erythrozyten--eine Modellstudie an Hunden.

In a nutritional tolerance study 36 young dogs were fed over 52 weeks high or low purine diets at an average paired feeding intake of 0.6 and 80 mg purine-N/MJ per day. The high purine diet resulted in a significant decrease of growth rate by -23% (Beagles) and -38% (Dalmatians) and of feed efficiency (-29 and -42%). The fasting levels of allantoin, uric acid and uracil in blood plasma were significantly increased. During the experiment a metabolic adaptation to the high purine diet decreased the plasma concentrations of uric acid, uracil and in part of allantoin. The high purine diet effected a significant increase of Km (2.5-fold) and of Vmax (1.6-fold) of uric transport through the erythrocyte membrane. The results documented disadvantageous effects of high purine nutrition during juvenile development.