Trypsin Inhibitor Activity and Tannin Content Do Not Affect Calcium Bioavailability of Three Commonly Consumed Legumes

Calcium bioavailability from legumes containing a range in trypsin inhibitor activity (TIA) and tannin concentration was studied. Three cultivars (Phaseolus vulgaris) were hydroponically grown and intrinsically labeled with ^4SCa. Raw and cooked legumes were fed to six groups of 6-wk old male Sprague-Dawley rats. Another group received an intraperitoneal (IP) injection of ⁴⁵Ca. An eighth group was fed a casein metal extrinsically labeled with ⁴⁵Ca. The absorption of calcium from legumes by rats averaged 47.1 ± 7.5% of IP dose. Average phytate content of the legumes was 1.7% and oxalate 0.37%. Raw legumes had an average of 15000 TIA units/g of whole bean, which were completely removed by cooking. Calcium absorption was unaffected by TIA or tannin content. Reduced availability of bean calcium was likely due to phytate and/or oxalate present in legumes.     

Bacteriocins Applied to Food Packaging Materials to Inhibit Listeria monocytogenes on Meats

Bacteriocins in powders were produced from milk-based media and applied to food packaging films. Nisin and pediocin “powders” were retained in casings during dialysis. Antilisterial casings were prepared by internal coating with pediocin. Antilisterial activity applied in powdered form was retained during processing and retained on contact food packaging surfaces. Pediocin powder was applied to plastic packaging bags at 7.75 μg/cm². Meats and poultry samples were inoculated with Listeria monocytogenes. The bags coated with pediocin powder completely inhibited growth of inoculated L. monocytogenes through 12 wk storage at 4°C. Applying bacteriocins to food packaging films is an effective approach to reduce L. monocytogenes contamination in meats and poultry.     

WHY HAVE EARNINGS PER WORKER STAGNATED?

ABSTRACT: The US is haunted by the virtual stagnation in the real average earnings per worker. The most common explanation is the combination of slow productivity growth and the smaller returns to productivity going to nonwage items such as health benefits, additional investment in productivity enhancing equipment, and to the increasing number of retirees. This explanation is insufficient to explain why, in many parts of the country, real average earnings have actually been decreasing, not just stagnating. This paper explores additional reasons why the US is experiencing stagnant national and often declining local earnings per worker. It uses a new data set, the ES202 data and focuses on one metropolitan area, Miwaukee, Wisconsin. It was found that the downward pressure on earnings per worker is due to such factors as the loss of high paying manufacturing jobs and the growth of employment in lower paying industries, new firms, growing firms that have decreasing earnings per worker, small businesses, and suburban businesses, which tend to pay less.     

Three‐dimensional bright‐field scanning transmission electron microscopy elucidate novel nanostructure in microbial biofilms

Bacterial biofilms play key roles in environmental and biomedical processes, and understanding their activities requires comprehension of their nanoarchitectural characteristics. Electron microscopy (EM) is an essential tool for nanostructural analysis, but conventional EM methods are limited in that they either provide topographical information alone, or are suitable for imaging only relatively thin (<300 nm) sample volumes. For biofilm investigations, these are significant restrictions. Understanding structural relations between cells requires imaging of a sample volume sufficiently large to encompass multiple cells and the capture of both external and internal details of cell structure. An emerging EM technique with such capabilities is bright‐field scanning transmission electron microscopy (BF‐STEM) and in the present report BF‐STEM was coupled with tomography to elucidate nanostructure in biofilms formed by the polycyclic aromatic hydrocarbon‐degrading soil bacterium, Delftia acidovorans Cs1‐4. Dual‐axis BF‐STEM enabled high‐resolution 3‐D tomographic recontructions (6–10 nm) visualization of thick (1250 and 1500 nm) sections. The 3‐D data revealed that novel extracellular structures, termed nanopods, were polymorphic and formed complex networks within cell clusters. BF‐STEM tomography enabled visualization of conduits formed by nanopods that could enable intercellular movement of outer membrane vesicles, and thereby enable direct communication between cells. This report is the first to document application of dual‐axis BF‐STEM tomography to obtain high‐resolution 3‐D images of novel nanostructures in bacterial biofilms. Future work with dual‐axis BF‐STEM tomography combined with correlative light electron microscopy may provide deeper insights into physiological functions associated with nanopods as well as other nanostructures.     

Compressive Creep of Al2O3 Single Crystals

Aluminum oxide single crystals deformed by dislocation glide and deformation twinning during compressive creep at 1400° to 1700°C. The activation energy for basal slip was a function of the applied stress and agreed with activation energies previously measured by observation of yielding phenomena. The overcoming of a large Peierls-Nabarro stress is the most probable rate-controlling mechanism. Rhombohedral twinning, a significant deformation mode in creep, depends on surface damage for nucleation. The activation energy for rhombohedral twin growth, a function of the applied stress, is substantially lower than that for basal slip. When basal slip and rhombohedral twinning occur concurrently, creep by basal slip results, but the presence of twins can substantially reduce the creep rate.     

Volatility of PuO2 in Nonreducing Atmospheres

The vapor pressure of plutonium dioxide (PuO₂) was investigated in the range 1450° to 1775°C in air, argon, and oxygen atmospheres by a transpiration technique. There were strong indications that PuO₂ can vaporize congruently or as a suboxide species, depending on the atmosphere. The δH°₂₉₈ for vaporization in 1 atm of oxygen is approximately 154,000 cal per mole. The estimated standard free energy of formation (δG°_f) of gaseous PuO₂ is −121,000 + 10.7 T from 1227° to 1827°C.     

Elastic Properties of Polycrystalline Ytterbium Oxide

The sonic resonance technique was used to determine the elastic moduli of polycrystalline Yb₂O₃ samples of rectangular cross section ranging in pore fraction from 0.058 to 0.27 at temperatures from 25° to 1000°C. The data showed that the Young's and shear moduli are best related to pore fraction by a linear equation and to temperature by the Wachtman equation. The Debye temperature for Yb₂O₃ was calculated from the Young's and shear moduli to be 385°K.     

Antimonates as Additives to Barium Titanate Dielectric Bodies

Antimonates of a number of the alkalis and alkaline earths and of several other metals were prepared and their ceramic and dielectric properties were determined. Only porous bodies could be produced from the individual anti-monates. Dielectric measurements on these bodies showed that they all had relatively low dielectric constants. The properties of dielectric bodies in the binary systems composed of the an-timonates of sodium, lithium, barium, strontium, magnesium, and lead plus barium titanate were determined. Additions of all the antimonates except that of magnesium had a depressing effect on the Curie peak of barium titanate, resulting in bodies with dielectric constants of 2000 or less, which showed relatively little variation with temperature. The addition of magnesium orthoantimonate to barium titanate produced a very rapid downward shift in the temperature of the Curie peak. X-ray studies showed that the antimonates of barium, strontium, sodium, and magnesium, when added to barium titanate in small amounts, formed solid solutions with slightly expanded lattice structures.