mm-wave Rydberg-Rydberg transitions gauge intermolecular coupling in a molecular ultracold plasma.

Out-of-equilibrium, strong correlation in a many-body system can trigger emergent properties that act to constrain the natural dissipation of energy and matter. Signs of such self-organization appear in the avalanche, bifurcation, and quench of a state-selected Rydberg gas of nitric oxide to form an ultracold, strongly correlated ultracold plasma. Work reported here focuses on the initial stages of avalanche and quench and uses the mm-wave spectroscopy of an embedded quantum probe to characterize the intermolecular interaction dynamics associated with the evolution to plasma. Double-resonance excitation prepares a Rydberg gas of nitric oxide composed of a single selected state of principal quantum number, n0. Penning ionization, followed by an avalanche of electron-Rydberg collisions, forms a plasma of NO+ ions and weakly bound electrons, in which a residual population of n0 Rydberg molecules evolves to a state of high orbital angular momentum, ℓ. Predissociation depletes the plasma of low-ℓ molecules. Relaxation ceases and n0ℓ(2) molecules with ℓ ≥ 4 persist for very long times. At short times, varying excitation spectra of mm-wave Rydberg-Rydberg transitions mark the rate of electron-collisional ℓ-mixing. Deep depletion resonances that persist for long times signal energy redistribution in the basis of central-field Rydberg states. The widths and asymmetries of Fano line shapes witness the degree to which coupling in the arrested bath (i) broadens the allowed transition and (ii) mixes the local network of levels in the ensemble.

Evolution from a molecular Rydberg gas to an ultracold plasma in a seeded supersonic expansion of NO.

We report the spontaneous formation of a plasma from a gas of cold Rydberg molecules. Double-resonant laser excitation promotes nitric oxide, cooled to 1 K in a seeded supersonic molecular beam, to single Rydberg states extending as deep as 80 cm;{-1} below the lowest ionization threshold. The density of excited molecules in the illuminated volume approaches 1x10;{13} cm;{-3}. This population evolves to produce free electrons and a durable cold plasma of electrons and intact NO+ ions.

Benefit of more but smaller meals at a fixed daily protein intake.

The influence of meal frequency on change of body weight and protein status, measured by level of amino acid oxidation (decarboxylation) in the postabsorptive state, was studied at a fixed daily protein intake. Growing rats (250g) were fed through gastric canula a feeding solution based on Nutrison Standard supplying 1.6g protein and 266kJ ME daily. This amount was given in either 2 large meals at the beginning and the end, or in 6 smaller meals, or by continuous infusion during entire dark period (10 hrs). After 3 weeks of feeding the mean growth rate of the rats fed continuously was nearly 20% higher than rats fed the same amount in 2 meals. The rats fed 6 meals a day had a growth rate rather similar to the rats fed continuously. The percentile recovery of label as 14CO2 in the breath after an intraperitoneal injection of [1-14C]leucine (4 hrs after last meal) was significantly higher (p.05) for the animals fed continuously (27% sd 2.6) compared to the rats fed 2 meals (21.9% sd 4.0). The value for 6 meal group was intermediate (24.5 sd 1.8). The results indicate that the metabolic utilization of a fixed daily amount of protein is clearly influenced by the way of supply. With respect to the change of body weight and protein status, animals have more benefit of the same amount of protein if the supply is more equable. It is suggested that the difference is caused by metabolic restriction for an adequate utilisation of large meals. Therefore large meals are supposed to cause a waste of amino acids in the postprandial phase. As a consequence amino acid amount that will be stored in the body to be available in the postabsorptive phase will be less.

Glucagon effect on glycogen content of chicken liver and muscles.

The experiments were carried out on broiler chickens divided randomly into two groups differing in the feeding level and, consequently, in the rate of weight gain. Half the chickens in each group were given a single dose of glucagon 150 micrograms/kg, and the other half received a control solution of glycine buffer. The chickens were investigated 1--1.5 hour after feeding and after 18--20 hours of starvation using the technique of biopsy of the liver and the external pectoral muscle. In the biopsy specimens the glycogen level was determined immediately before glucagon administration and 30--60--90 minutes after the injection. It was found that glucagon injection caused either a rise or a fall in the glycogen level in the liver and that the trend of these changes depended on the feeding level of the chickens and on the duration of starvation of the birds before treatment. The glycogen level in the pectoral muscle of the chickens kept on the higher feeding level was observed to fall one hour after glucagon administration.

Effect of glucagon on the metabolic rate in growing chicken.

The investigations were carried out on 70 growing broiler chickens. The chickens were kept on a higher and the other ones on the lower level of nutrition. As a result of this the rate of growth was different in both groups. Glucagon had a strong calorigenic effect, reaching a peak 30 min after its injection. This effect of glucagon increased progressively with the growth and development of birds reaching a maximum in chickens aged about 7 weeks, and weighing approx. 1200 g. In the birds examined 2 hours after feeding the calorigenic effect of glucagon was most expressed in birds maintained on the low nutrition levels. The fall of RQ after glucagon injection may suggest that this hormone has a strong lipolytic action.