IEA joint trials: New lessons from old plantations

Two international trials of potential biomass species families and clones planted in 1985 have been analyzed to determine changing patterns in growth, diseases, and insects. In the Swedish trial, with close spacing and short rotations, Salix viminalis clones gave the best average yield of 17.4 Mg/Ha/yr on the first coppice rotation. In the Minnesota, USA trial, with wider spacings and a longer rotation Populus alba hybrid clones gave the best average yields of 5.5 Mg/Ha/yr. The most important disease and insect problems encountered were Septoria musiva stem cankers on some Populus clones; frost die back in some Salix clones; and the leaf blotch miner, Fenusa dohrnii, on most Alnus families. Recommendations for future international cooperation in field trials are presented.     

Microstructural Effects of Ion Implantation on Molybdenum

The effects of ion implantation and subsequent annealing on the microstructure of molybdenum have been investigated by transmission electron microscopy. The ions investigated were carbon, nitrogen, and tellurium. The ion-induced damage was found to give rise to grain boundary migration phenomena both during implantation and during subsequent annealing. Precipitation or ordering was found to occur for each ion on annealing.     

Mechanisms of char production from oxidized cellulose

A multi-technique approach, incorporating nuclear magnetic resonance (NMR), elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis and surface area determination, has been used to investigate the formation of chars by oxidized cellulose. It was found that oxidation of the cellulose tends to increase the surface area of the resulting char. NMR, elemental analysis and DSC show how cellulose oxidation tends to increase aromaticity and cross-linking. This, in turn, decreases diffusion rates of volatiles out of the oxidized cellulose during pyrolysis, giving denser carbons and higher BET surface areas.     

Measles, polio and tetanus toxoid antibody levels in Gambian children aged 3 to 4 years following routine vaccination

A nation-wide cross-sectional survey of 816 children 3-4 years old was carried out in The Gambia between September 1990 and July 1991 to assess the seroprevalence of antibodies against 3 diseases included in the expanded programme on immunization: measles, poliomyelitis and tetanus. Among 689 children whose records were available, 94.5% were fully immunized. Measles vaccine was administered to 97% of the children and 91% of these had detectable antibodies at the time of the survey. Antibodies against type 1 and type 3 polioviruses, after up to 6 doses of oral polio vaccine, were present in 88.1% and 89.3% of the children respectively. Ninety-seven percent of the children who had received 4 doses of diphtheria-pertussis-tetanus vaccine (DPT) and 91% of those who received 3 doses had detectable tetanus toxoid antibodies at the age of 3-4 years. This study shows that serological responses to EPI vaccines given in infancy persist at very satisfactory levels throughout early childhood.     

Response–reinforcer associations after caudate-putamen lesions in the rat: Spatial discrimination and overshadowing–potentiation effects in instrumental learning.

Exp I, with 12 male hooded rats, demonstrated that Ss with caudate-putamen lesions exhibited an impairment in the acquisition and reversal of a spatial maze task when compared with unoperated control Ss. Exp II, with 24 Ss, investigated leverpress responding supported by a VI schedule in 3 groups of Ss: a group with caudate-putamen lesions, a group with lesions of the posterior cortex, and an unoperated control group. The presentation of a 0.5-sec, response-contingent light correlated with reinforcement generated an elevated response rate in the 2 operated groups but tended to suppress responding in the control group, perhaps by overshadowing the response–reinforcer relation. Only the group with cortical lesions maintained the elevated rate when the light was uncorrelated with food delivery. Exp III confirmed for these same Ss that caudate-putamen lesions produced a spatial learning deficit. No deficit was observed in the posterior cortex group. It is suggested that caudate-putamen lesions disrupt the mechanism underlying the response–reinforcer association on which spatial maze learning and free operant responding in part depend. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An analysis of the coupling of an injection laser diode to a planar LiNbO3waveguide

Calculated butt coupling efficiency between a GaAlAs double heterostructure laser and a single-mode LiNbO3Ti-diffused optical waveguide is presented in this paper as a function of the transverse displacement, the angular alignment, the longitudinal separation between the laser and the waveguide end surfaces, the radiation field of the laser diode and its dependence on the laser diode structure, and the mode profile of the waveguide and its dependence on experimental diffusion parameters. The maximum efficiency is less than 40 percent because of the mismatch between the waveguide mode and the laser radiation, caused primarily by the experimental limitations in their structures. The effect of the reflection of the waveguide end surface on the laser oscillation has also been estimated.     

Fatal meconium aspiration in spite of appropriate perinatal airway management: pulmonary and placental evidence of prenatal disease

The cytoskeletal components of hamster oocytes, zygotes, and spontaneously activated parthogenotes were examined after immunocytochemical labeling. Microtubules were found only in the anastral, tangentially arranged second meiotic spindle of unfertilized oocytes. Taxol treatment of unfertilized oocytes greatly augmented astral microtubules in both the metaphase II spindle and the cortex. Disruption of the meiotic spindle microtubules with nocodazole resulted in cortical chromosomal scattering. During hamster sperm incorporation and pronuclear formation, no sperm aster was detected in association with the male DNA. Instead, a large overlapping array of microtubules assembled in the cortex. By mitosis, this interphase array disassembled and an anastral metaphase spindle formed. Microtubule and chromatin configurations were also imaged in hamster oocytes injected with human sperm. Astral microtubules were absent from the sperm centrosome. The implications of these results are discussed in relation to the hamster oocyte penetration assay, a test commonly used by in vitro fertilization clinics to demonstrate the fertilizing ability of human sperm. We conclude that since hamsters and humans follow different methods of centrosome inheritance, maternal and paternal, respectively, the hamster may be an inappropriate model for exploring microtubule and centrosomal defects in humans or for assaying postinsemination forms of human male fertility defects.     

Impact of specification changes on chloride-induced corrosion service life of bridge decks

A model was developed to determine the time to first repair and to subsequently rehabilitate concrete bridge decks exposed to chloride deicer salts. Said model incorporates the statistical nature of factors affecting the corrosion process. The time to first repair and rehabilitate was predicted for 10 bridge decks built in Virginia between 1981 and 1994.The model was validated using historical service life data for 129 bridge decks built in Virginia between 1968 and 1972. The time for rehabilitation predicted for the newer set of bridge decks was approximately 13 years longer than the normalized time for rehabilitation projected for the older bridge decks. The increase in time for rehabilitation for the newer set of bridge decks was attributed to a reduction in the specified maximum water/cement ratio and increase in clear cover depth. The probabilistic model is shown to be an advancement over the deterministic model currently in use.     

Methotrexate therapy in rheumatoid arthritis: a life table review of 587 patients treated in community practice

To determine whether methotrexate (MTX) maintains its effectiveness in rheumatoid arthritis (RA) in the setting of community based private rheumatology practice we used life table analysis to review the combined experience of a group of these practices. Of 587 patients with RA who started to take MTX, total termination rate at 70 months was 24.4% with most terminations prompted by drug toxicity. Older age (greater than 65 years) was associated with higher rates of toxicity. Treatment termination rates varied substantially between rheumatologists. We conclude that MTX therapy for RA is well tolerated and maintains effectiveness for at least 70 months.     

Contributions of Transformation and Microcracking to the Plastic Deformation of Magnesia-Partially-Stabilized Zirconia

The measured plastic deformation of Mg-PSZ under stress contains contributions from both transformation and microcracking. A method is described to separate the contributions from transformation and microcracking for samples deformed in uniaxial tension. Such a separation enables the ratio of the longitudinal to transverse strains arising from the transformation to be estimated. The results are compared to the predictions of the shear–dilatation model of Chen and Reyes-Morel. Serious discrepancies are found between the experimental results and the predictions of the model and the possible reason for this is discussed.