Longitudinal optical phonon-plasmon coupling in ionic semiconductors

The coupling of free carriers and lattice vibrational modes is studied in CdS and InSb by room temperature far infrared reflectance measurements. When the free carrier concentration is such that the plasma frequency is at or near the longitudinal optical mode frequency it is shown that while the transverse modes remain fixed, the longitudinal modes mix with the plasma mode and are shifted in a manner similar to that described by Varga in 1965. Using the dielectric function for the coupled system permits the determination of electron effective masses by reflectance measurements with lattice effects excluded. This method allows one to investigate the frequency shifts and effective mass values on crystals in which the mobility varies by more than an order of magnitude as demonstrated by the analysis of both CdS and InSb. In the case of CdS where the polaron coupling constant is large enough to have noticeable effects, account is taken of the polaron mass and of the additional absorption in the plasma mode at frequencies above the longitudinal optical phonon frequency --Abstract, page i

The Effects of Restrictive Tuition Legislation on Nineteen Selected Class II School Districts in Nebraska

During the 1973 Legislative Session, LB 314 was introduced to the Eighty-Third Legislature. It provided for an act to amend Section 79-4102, Reissue Revised Statutes of Nebraska, 1943, relating to schools to provide the maximum non-resident tuition rate and to repeal the original section. LB 314, which would have provided a maximum non-resident tuition rate, was heard by the Education Committee on March 12, 1973, and indefinitely postponed on April 3, 1973

A Good Treaty

Time and space do not permit me to comment on the many worthy provisions within Protocol 1, so I have chosen two articles in the Protocol which strike me as important in the light of my experience: 1) Article 26 - Medical Aircraft in Contact or Similar Zones, and 1I) Article 77 - Protection of Children

The Relation Between Soil Characteristics, Water Movement and Nitrate Contamination of Ground Water

Soils from several areas in Kentucky were placed in columns and leached with Ca(NO3)2. Subsoils high in iron oxide were found to retard the leaching of nitrate very significantly. In other soils, the nitrate moved through as fast as or slightly faster than the water. Field application of nitrogen to corn was most efficient when done in the spring or summer near the time that the corn takes it up. The one exception to this was a red soil, where fall application of nitrogen resulted in little loss due to the retarding effect mentioned in the first paragraph. Soils on which a sod or cover crop is killed and in which corn is planted have little loss of water by evaporation. Because of this, much more water movement occurs and nitrate moves out of the soil during the summer. In contrast, the soil without a killed sod mulch suffers no loss of nitrate during the growing season. Stream samples taken in 1971 and 1972 during the months of January through May showed a poor relation between nitrate in the water and land use, The highest nitrate was found in a stream draining a grassland watershed where little fertilizer is used. The tile drain effluent and total water reaching a drainage ditch were determined. The nitrate in the tile effluent was much higher than that in the non-tile drainage. This leads to the conclusion that the nitrate concentrations of tile effluents are not reliable indicators of nitrate leaving a tiled field

A non-apoptotic role for caspase-9 in muscle differentiation

Caspases, a family of cysteine proteases most often investigated for their roles in apoptosis, have also been demonstrated to have functions that are vital for the efficient execution of cell differentiation. One such role that has been described is the requirement of caspase-3 for the differentiation of skeletal myoblasts into myotubes but, as yet, the mechanism leading to caspase-3 activation in this case remains elusive. Here, we demonstrate that caspase-9, an initiator caspase in the mitochondrial death pathway, is responsible for the activation of caspase-3 in differentiating C2C12 cells. Reduction of caspase-9 levels, using an shRNA construct, prevented caspase-3 activation and inhibited myoblast fusion. Myosin-heavy-chain expression, which accompanies myoblastic differentiation, was not caspase-dependent. Overexpression of Bcl-xL, a protein that inhibits caspase-9 activation, had the same effect on muscle differentiation as knockdown of caspase-9. These data suggest that the mitochondrial pathway is required for differentiation; however, the release of cytochrome c or Smac (Diablo) could not be detected, raising the possibility of a novel mechanism of caspase-9 activation during muscle differentiation.</jats:p

Urinary liver fatty acid-binding protein: another novel biomarker of acute kidney injury

Liver fatty acid-binding protein (L-FABP) binds selectively to intracellular free unsaturated fatty acids and lipid peroxidation products during hypoxic tissue injury. Urinary L-FABP is a potential biomarker for the detection and assessment of acute kidney injury (AKI). Ferguson et al. have demonstrated in a cross-sectional study that urinary L-FABP is an excellent biomarker of AKI and may be useful in predicting dialysis-free survival. This study did not assess utility for early diagnosis of AKI

Effect of Hatchery Rearing Environment on Survival an Performance of Outplanted Wetslope Cutthroat Trout Used for Population Recovery

Reintroduction of native fish stocks is an important management tool used to mitigate the effects of invasive species and loss of habitat. One means of reintroduction is the use of hatchery fish to create or supplement native populations in areas of their historic range. The use of hatchery fish for reintroduction can be inefficient as low survival and competition with wild fish has been noted. This study has attempted to develop and evaluate the effectiveness of enriched hatchery rearing strategies on increasing the efficiency and effectiveness of hatchery reintroductions by examining behavioral, morphological, and physiological differences among westslope cutthroat trout (Oncorhynchus clarkii lewisi) reared in varying levels of enriched environments. Social behavior, predator avoidance, cover seeking behavior, fin condition, growth, stress response, immune function, and muscle content have been evaluated during the first phase. Preliminary results show divergence in growth, fin condition, and social and cover seeking behaviors among the different rearing environments. Findings have suggested that manipulating hatchery rearing environments can alter behavior and morphology but determining if these alterations improve survival once outplanted is currently unknown