A study of the ecology and taxonomy of micromonospora in the natural environment

Selective isolation procedures were developed for the isolation of Micromonospora from natural environments. Methods developed involved the use of heat treatment and the use of antibiotic incorporated media using lincomycin and novobiocin. It was found that heat treating air dried soil samples in a dry oven at 120°C for 60 minutes drastically reduced the number of both bacteria and streptomycetes occurring on the isolation plates thereby allowing for the selective isolation of Micromonospora. Additionally the most effective concentration of antibiotics for the selective isolation of Micromonospora was found to be lOpil/ml novobiocin and 10/xl/ml lincomycin. A spore specific extraction procedure was also developed, again exploiting the ability of Micromonospora spores to withstand heat treatment, to follow the fate of Micromonospora spores and mycelia in artificial soil microcosms. Comparison of the survival of both the spore and mycelial component of M. chalcea and M. Julvopurpurea populations indicated that heat treating lOg microcosms for 20 minutes at 70°C allowed the maximum recovery of spores present whilst deselecting completely the mycelial population. The ability of Micromonospora chalcea and M. Julvopurpurea to survive in sterile soil microcosms was studied over 30 days. Both species showed marked germination and sporulation cycles mirroring streptomycetes. Both species consistantly showed significant germination at Day 1 with spore numbers starting to increase by Day 2 (ca. 10^ spores/g soil). Following rapid sporulation at Day 5. a plateau at ca. 10^ to 10^ c.f.u./g soil was attained. Using phenotypic data, including antibiotic resistance profiles, Micromonospora strains, comprising both type strains and wild isolates, were clustered using numerical taxonomic methods. Clustering of the largest set of data (121 strains/179 characteristics) using the NTSYS clustering package, gave 14 distinct species-groups. The character state data obtained for clusters defined at the 77.5% Ssm similarity level were then used to develop a probabilistic identification matrix for the rapid identification of Micromonospora

Deviations from early--time quasilinear behaviour for the quantum kicked rotor near the classical limit

We present experimental measurements of the mean energy for the atom optics kicked rotor after just two kicks. The energy is found to deviate from the quasi--linear value for small kicking periods. The observed deviation is explained by recent theoretical results which include the effect of a non--uniform initial momentum distribution, previously applied only to systems using much colder atoms than ours

A study of the effects of size-controlling rootstocks on spurring, blooming and fruiting habits of two apple varieties

Size-controlling apple rootstocks have been known and used for centuries. At present, there is considerable interest in smaller than standard size trees because they allow almost all orchard operations from pruning to harvesting to be done easier and perhaps with less labor. The smaller trees also present more opportunity for mechanical harvesting. Some methods besides rootstocks that may be used to dwarf apple trees are as follows: (1) scoring or ringing the trunk, (2) scion variety selection such as spur types, (3) chemicals such as Alar or B-9, (4) severe pruning, (5) low fertility levels, and (6) site selec-tion such as shallow, infertile or sandy soils. Although all these methods have potential, dwarfing by rootstock is most satisfactory at pre-sent. Dwarfing of apple trees offers possible improvement in fruit color and fruit characteristics. Evidence indicates dwarf trees are more open than standard trees. This makes possible more efficient use of sunlight. Therefore, more sugars may be manufactured with better fruit color resulting and more spurs developing. Openness of the tree is probably related to Auxin factors which relates to branch angles. Apple flowers are usually formed from buds on short shoots known as spurs. Spurs are usually formed from leaf buds on wood in its second growing season. Spurs usually produce flower buds the year they are formed and every other year thereafter. Fruit set usually occurs with blooming. Annual production is related to numbers of live vigorous spurs on various aged wood throughout the tree and the fruiting of these spurs. Past studies with dwarfing apple rootstocks have been on tree size, yields and performance of scion varieties with various soils and climates. The objectives of this investigation were to determine the effects of eight size-controlling rootstocks on leaf bud numbers, and number of spurs developing, blooming, and fruiting on wood of various ages

A plan for spacecraft automated rendezvous

An automated rendezvous approach has been developed that utilizes advances in technology to reduce real-time/near real-time flight operations support personnel to an acceptable level that is near the minimum without jeopardizing the success of the mission. The on-board flight targeting uses a rule-based system to select the pursuit vehicle phasing orbits and uses precise navigation updates from the pursuit/target spacecraft made possible by the global positioning system receivers/processors on both spacecraft to adjust the phasing orbits and achieve rendezvous. The ascent-to-orbit targeting for the pursuit vehicle has been successfully decoupled from the on-orbit orbit transfer phasing targeting. Typical launch window data have been developed for the heavy lift launch vehicle and cargo transfer vehicle for a Space Station Freedom rendezvous mission

Typology, Tabernacle and Tradition: A History of Interpretation of Hebrews 9:11-14

The texts of the Bible have been used and interpreted in various ways across different time periods and different cultures, and there is much to be gained by studying these changes. Changing attitudes about and uses of Scripture tell us something about other changes taking place in society. They reflect new ideas about religion, knowledge, and authority. Most of all, they demonstrate the techniques used by pastors, theologians, and other authors to make texts written long ago relevant to contemporary problems. The purpose of my study is to use Hebrews 9:11-14 to look at the ways in which the interpretation of Scripture and the uses of Scripture change across time and geographic locations. By analyzing the text itself in its first century context, as well as documents citing this passage from the Early Church, the Middle Ages, the Reformation, and the present day, I am able study both the ways that the interpretation of this particular passage has changed, and how methods of biblical interpretation themselves have changed

Native Plant Allelopathy: A Potential Approach to Limit Invasive Grass Encroachment in Thorn Forest Restoration

Less than 5% of the Tamaulipan thorn forest remains in the United States. For this reason, there have been many attempts at restoration of this ecosystem. Oftentimes these attempts are unsuccessful due to the high prevalence of invasive African grasses that outcompete the seedlings. In an effort to improve the efficacy of these restoration efforts, native plant allelopathy has been examined for its ability to exclude invasive guineagrass. Native species were surveyed and selected species were tested for allelopathy in laboratory bioassays. The species that exhibited allelopathy in the laboratory were then evaluated in pot experiments for their ability to reduce fungal infection in guineagrass roots, grass stem mortality, and grass growth, and in the field as mulch for their ability to reduce guineagrass cover and growth. There were several potentially allelopathic species identified, stem mortality was increased by E. ebano, V. schaffneri, and Z. fagara. The mulch of Z. fagara almost entirely excluded invasive grass growth and mulch from E. anacua and V. schaffneri reduced invasive grass growth. These experiments suggest that mulch from Z. fagara could be very useful in restoration due to its ability to prevent guineagrass growth