L∞ spaces and derived loop spaces

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FT-IR spectroscopy of CAI and chondrules in primitive chondrites: techniques and first results

From the Introduction: Here we present preliminary mid-infrared spectra of CAI, chondrules and matrix from the CV3.2 carbonaceous chondrite Allende. This is part of our ongoing project to compile a database of infrared and optical spectra of minerals and components of primitive meteorites. These spectra should allow a better comparison with spectra from astronomical sources e.g. from dust and molecular clouds or young solar systems

Effect of Oxygen-Limiting Tidal Conditions on Muscle Metabolism and Structure in the Giant Acorn Barnacle, Balanus nubilus

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph pO2, pCO2, pH, Na+, Cl-, K+, and Ca+ then excised tergal depressor (TD) and scutal adductor (SA) muscles to determine citrate synthase (CS) activity, lactate dehydrogenase (LDH) activity, and D-lactate levels. We also prepared a subset of SA and TD muscles from the chronic barnacles for histological analysis of fiber diameter (Feret’s), cross-sectional area (CSA), mitochondrial distribution and relative density, as well as nuclear distribution and myonuclear domain size. There was a significant decrease in hemolymph pO2 and pCO2 following acute and chronic anoxic immersion, whereas air emersion pO2 and pCO2 was comparable to normoxic levels. Fiber CSA and diameter did not change significantly in either tissue, while myonuclear domain size in SA muscle was significantly lower in the anoxic and emersion groups than the normoxic control. Neither CS, nor LDH activity, showed any significant treatment effect in either tissue, whereas both muscles had significantly higher D-lactate levels after air emersion following acute (though not chronic) exposure. Thus far, our findings indicate that B. nubilus experience a general reduction in aerobic metabolism under anoxia, emersion is only mildly oxygen-limiting, and that muscle plasticity is occurring during chronic emersion and anoxia

Mid-infrared spectroscopy of CAI and AOA from the Allende CV3.2 chondrite

Mid-infrared spectra of bulk CAI from the CV3.2 chondrite Allende are presented and compared with astronomical spectra of cometary dust, zodiacal light,the circumstellar disk of beta Pictoris and dust around the red supergiant PR Per

To what distances do we know the confining potential?

We argue that asymptotically linear static potential is built in into the common procedure of extracting it from lattice Wilson loop measurements. To illustrate the point, we extract the potential by the standard lattice method in a model vacuum made of instantons. A beautiful infinitely rising linear potential is obtained in the case where the true potential is actually flattening. We argue that the flux tube formation might be also an artifact of the lattice procedure and not necessarily a measured physical effect. We conclude that at present the rising potential is known for sure up to no more than about 0.7 fm. It may explain why no screening has been clearly observed so far for adjoint sources and for fundamental sources but with dynamical fermions. Finally, we speculate on how confinement could be achieved even if the static potential in the pure glue theory is not infinitely rising.Comment: 16 pages, 5 figures. Additional arguments presented, a new figure and references adde

Size frequency variation of an emerging fisheries species across its biogeographical range

Kellet\u27s whelk (Kelletia kelletii), a large subtidal gastropod is the basis for an emerging bycatch fishery in California. This commercial fishery has increased dramatically in the past two decades, but there is little biological information available to inform its management. There are currently no size limits and only seasonal restrictions for commercial and recreational fishing for Kellet’s whelk in California with annual total allowable catch at 100,000 pounds. After surveying 28 subtidal rocky reefs across the Kellet’s whelk range, our results indicate large natural variation in size frequencies, specifically between the mainland and island populations. Designing harvesting strategies that would maintain these size frequency distributions – e.g., a larger size limit at the islands and a smaller size limit at the mainland populations -- may generate more sustainable and productive economic and ecological outcomes