Detection of Neutral Carbon in the M 31 Dark Cloud D478

Emission from the 492 GHz CI tranition was detected towards the dark cloud D478 in M31. Using existing 12CO and 13CO measurements, models for the gas properties of D478 are discussed. The observed CO and C line ratios can be explained by two-component models (dense cores and tenuous envelopes); single-density models appear less likely. The models indicate temperatures T(kin) = 10 K. The beam-averaged C column density is 0.3 - 0.8 times that of CO, whereas the total carbon to hydrogen ratio N(C)/N(H) = 5-3 times 10**-4. The resulting CO-to-H2 conversion factor X is about half that of the Solar Neighbourhood. With temperatures of about 10 K and projected mass densities of 5-10 M(sun)/pc**2 there appears to be no need to invoke the presence of very cold and very massive clouds. Rather, D478 appears to be comparable to Milky Way dark cloud complexes such as the Taurus-Auriga dark cloud complex.Comment: 7 Pages, 1 Figure; accepted by A&

Oxygen supply and consumption in soilless culture: evaluation of an oxygen simulation model for cucumber

A soil oxygen simulation model (OXSI) was tested and evaluated for evaluating growing media with respect to aeration. In the model, local oxygen concentrations are calculated from coefficients of diffusion and consumption (respiration), assuming equilibrium conditions. Apparent oxygen diffusion coefficients (D) were determined under laboratory conditions in 5 cm high samples at different water contents (-3.2, -10 and -20 cm pressure heads). D values were positively related to air-filled porosity (AFP). For fine-graded perlite D ranged from 9.10-7 at AFP of 34 percent to 5.10-9 m2s-1 at AFP of 19 percent. Possibly due to absence of closed pores in rockwool, the AFP vs. D relation was different for rockwool compared to perlite: D for rockwool ranged from 2.10-6 at AFP of 56 percent to 3.10-9 m2s-1 at AFP of 3 percent. A greenhouse experiment with cucumber was carried out to determine respiration and realised oxygen concentrations. The cucumbers were grown in 20 cm high, 3.5 litre containers filled with fine-graded perlite and supplied with high-frequency irrigation. AFP varied between 25 and 45 percent. At three heights and on four occasions during growth, oxygen concentration ( f volume) in the medium varied between 16.6 and 20 n the perlite. Root respiration of the cucumbers as determined by two independent methods (in vivo and in vitro) ranged from 1.4 to 5.4 10-6 ml.ml-1.s-1. Using these respiration rates, OXSI calculated that no oxygen depletion may occur at D > 1 to 5 10-7 m2s-1, corresponding with an AFP of 30 percent for both perlite and rockwool. Anoxic condtions were calculated for D values of 10-8 m2s-1, corresponding with AFP below 10 percent for rockwool and 20 percent for perlite

Development of a Model to Predict Intramuscular Fat in Live Pigs Using Real-Time Ultrasound

Recent developments in real-time ultrasound technology offer producers an opportunity to estimate intramuscular fat in live pigs. Genetic improvement of intramuscular fat will continue as an emphasis in swine breeding programs and genetic progress in this important trait will be possible through implementation of this technology

2007 Review—ISU Lauren Christian Swine Research Center, Madrid, Iowa

The Lauren Christian Swine Research Center has a long history of significant contributions to swine research programs in the Animal Science Department at Iowa State University. Researchers in swine breeding and genetics, reproductive physiology, nutrient management, and meat science currently utilize animals housed at the farm. Additional animals are used in departmental teaching and extension activities

Comparison of Serial Ultrasonic Measurements of Loin Muscle Area, Backfat, and Intramuscular Fat Percentage Between Pigs Sired by Boars from Two Different Time Periods

Results of this study demonstrate that significant progress toward the enhancement of carcass composition has been realized within the Duroc breed since the mid 1980’s; however, this improvement has been at the expense of meat quality traits such as intramuscular fat. This report also suggests that the deposition rates and growth patters of loin muscle area, tenth-rib backfat, and intramuscular fat percentage have not been significantly affected by long-term selection for increased carcass leanness

Genetic Parameter Estimates of Production, Meat Quality, and Sensory Traits in Duroc Swine

Heritability estimates detected for carcass composition, meat quality, and sensory measures indicate that improvement in these traits may be attained if adequate selection pressure is applied. Estimates obtained within the current population illustrate that substantial genetic relationships exist between many economically relevant traits. Genetic parameters estimated after 6 generations of selection for intramuscular fat indicate that the use of ultrasound technology may provide a non-invasive method for genetic improvement of IMF and other meat and eating quality components. However, genetic improvement programs aimed at meat quality improvement should be aware of possible adverse effects on carcass leanness, muscling, and loin color

Direct and Correlated Responses to Selection for Intramuscular Fat in Duroc Swine

At the present state of technology, intramuscular fat percentage can be accurately evaluated in live pigs and utilized in conjunction with sib carcass data for estimation of breeding values for intramuscular fat. Within the population under study, selection on resulting EBV has yielded a significant phenotypic change in all measures of IMF. Phenotypic gain in IMF established through selection in the current study resulted in IMF levels that may be useful for differentiation of sire lines for use in muscle quality-based niche markets. Results from this study illustrate that phenotypic improvement of IMF may correspond to an increase in objective tenderness, and shed light into the possible ramifications of this response in measures of carcass composition. Intramuscular fat may be used in swine breeding programs as an indicator of general product palatability; however, sensory characteristic improvements are likely to be slow when simultaneous improvement in other trait categories is also pursued

Polariton Squeezing in Semiconductor Microcavities

We report squeezed polariton generation using parametric polariton four-wave mixing in semiconductor microcavities in the strong coupling regime. The geometry of the experiment corresponds to degenerate four-wave mixing, which gives rise to a bistability threshold. Spatial effects in the nonlinear regime are evidenced, and spatial filtering is required in order to optimize the measured squeezing. By measuring the noise of the outgoing light, we infer a 9 percent squeezing on the polariton field close to the bistability turning point

Operations on integral lifts of K(n)

This very rough sketch is a sequel to arXiv:1808.08587; it presents evidence that operations on lifts of the functors K(n) to cohomology theories with values in modules over valuation rings of local number fields, indexed by Lubin-Tate groups of such fields, are extensions of the groups of automorphisms of the indexing group laws, by the exterior algebras on the normal bundle to the orbits of the group laws in the space of lifts.Comment: \S 2.0 hopefully less cryptic. To appear in the proceedings of the 2015 Nagoya conference honoring T Ohkawa. Comments very welcome