INTAP - Interplanetary Trajectory Analysis Program

Computer program for studying point-to-point nonintegrated heliocentric conic section trajectorie

Relationships Between Previous School and Life Experiences of Pre-Service Elementary Teachers and Their Attitudes Toward Science and Science Teaching

This study examined the relationships between previous school and life experiences of pre-service elementary school teachers at the University of North Dakota and their attitudes toward science and science teaching. The study incorporated both qualitative and quantitative methodologies. The first six pre-service teachers from one of the science methods class who volunteered were selected for taped private interviews. Based on this information a quantitative survey (Sampson Survey I) was designed for discovering the relationship between past experiences of pre-service teachers and their current attitudes toward science and teaching science. Additionally, the Shrigley Science Attitude Scale (Shrigley, 1974b), which assesses attitudes toward science, was given to two science methods classes (57 students) enrolled at the University of North Dakota during the fall semester, 1990. The population for the surveys was not randomly selected from all the science methods classes offered at the University of North Dakota; therefore, the results of the research apply only to the one setting where the research was conducted and may not be transferable to students at other universities. Forty-one of pre-service elementary teachers had confidence in their general science knowledge, 70% to teach the life sciences, 58% to teach ecology, 53% to teach earth sciences, 46% to teach space sciences, and 28% to teach physical sciences. The most important antecedent for a positive attitude toward science was the memory of how a particular science was taught to the students. The correlations indicate that confidence in the physical sciences (chemistry, physics) is more school-oriented than in the other branches of science. Science acquired outside of school arouses interest and curiosity in science, especially life sciences. There were significant correlations (p $\u3c$.01) between those with confidence in their general science knowledge and in their ability to teach all sciences, and those who believe anybody can be a scientist. A significant correlation (p $\u3c$.01) was found between having confidence to teach all sciences and the deliberate practice of reading articles about science to stay informed. The study indicated that the qualitative and quantitative data show similar patterns and relationships

A Local Approach: Homeland Security Officers

It has become apparent that true preparedness for a catastrophic event requires a strong local component. However, the patchwork of full and part time operators in a range of disciplines preparing for a variety of responsibilities creates the risk of an inexact or inefficient response. As a result, this document will support the idea that in order to improve the level of preparedness of municipalities, one full time police officer should be assigned to the newly created position of Homeland Security Officer (HSO), and be tasked with all manner of responsibilities for the most effective example of homeland security. This Project will introduce the Homeland Security Officer position; its responsibilities and justifications. Various chapters will examine the position through the prisms of Management, Public Sector Policy Analysis, Multi-disciplinary Collaboration, and Public Health Emergencies. Two Strategic Plans are included: one for the Police Department of Pleasantville, New York, and a second for Terrorist Threats associated with living and / or working as an American in Germany. Specific threats to Pleasantville are also considered. A Threat Assessment of an attack similar to the one on Mumbai in 2008; and a Model Based Vulnerability Analysis (MBVA) of the Critical Infrastructure of the Drinking Water supply. Finally, there are some larger issues considered: Constitutional Issues in Homeland Security and International Human Rights Concerns for America

Lack of sex chromosome specific meiotic silencing in platypus reveals origin of MSCI in therian mammals

Background: In therian mammals heteromorphic sex chromosomes are subject to meiotic sex chromosome inactivation (MSCI) during meiotic prophase I while the autosomes maintain transcriptional activity. The evolution of this sex chromosome silencing is thought to result in retroposition of genes required in spermatogenesis from the sex chromosomes to autosomes. In birds sex chromosome specific silencing appears to be absent and global transcriptional reductions occur through pachytene and sex chromosome-derived autosomal retrogenes are lacking. Egg laying monotremes are the most basal mammalian lineage, feature a complex and highly differentiated XY sex chromosome system with homology to the avian sex chromosomes, and also lack autosomal retrogenes. In order to delineate the point of origin of sex chromosome specific silencing in mammals we investigated whether MSCI exists in platypus. Results: Our results show that platypus sex chromosomes display only partial or transient colocalisation with a repressive histone variant linked to therian sex chromosome silencing and surprisingly lack a hallmark MSCI epigenetic signature present in other mammals. Remarkably, platypus instead feature an avian like period of general low level transcription through prophase I with the sex chromosomes and the future mammalian X maintaining association with a nucleolus-like structure. Conclusions: Our work demonstrates for the first time that in mammals meiotic silencing of sex chromosomes evolved after the divergence of monotremes presumably as a result of the differentiation of the therian XY sex chromosomes. We provide a novel evolutionary scenario on how the future therian X chromosome commenced the trajectory toward MSCI.Tasman J. Daish, Aaron E. Casey and Frank Grutzne

Construction of a highly enriched marsupial Y chromosome-specific BAC sub-library using isolated Y chromosomes

The Y chromosome is perhaps the most interesting element of the mammalian genome but comparative analysis of the Y chromosome has been impeded by the difficulty of assembling a shotgun sequence of the Y. B AC-based sequencing has been successful for the human and chimpanzee Y but is difficult to do efficiently for an atypical mammalian model species (Skaletsky et al. 2003, Kuroki et al. 2006). We show how Y-specific sub-libraries can be efficiently constructed using DNA amplified from microdissected or flow-sorted Y chromosomes. A Bacterial Artificial Chromosome (BAC) library was constructed from the model marsupial, the tammar wallaby (Macropus eugenii). We screened this library for Y chromosome-derived BAC clones using DNA from both a microdissected Y chromosome and a flow-sorted Y chromosome in order to create a Y chromosome-specific sub-library. We expected that the tammar wallaby Y chromosome should detect ∼100 clones from the 2.2 times redundant library. The microdissected Y DNA detected 85 clones, 82% of which mapped to the Y chromosome and the flow-sorted Y DNA detected 71 clones, 48% of which mapped to the Y chromosome. Overall, this represented a ∼330-fold enrichment for Y chromosome clones. This presents an ideal method for the creation of highly enriched chromosome-specific sub-libraries suitable for BAC-based sequencing of the Y chromosome of any mammalian species

Evolution, expression and meiotic behavior of genes involved in chromosome segregation of monotremes

Chromosome segregation at mitosis and meiosis is a highly dynamic and tightly regulated process that involves a large number of components. Due to the fundamental nature of chromosome segregation, many genes involved in this process are evolutionarily highly conserved, but duplications and functional diversification has occurred in various lineages. In order to better understand the evolution of genes involved in chromosome segregation in mammals, we analyzed some of the key components in the basal mammalian lineage of egg-laying mammals. The chromosome passenger complex is a multiprotein complex central to chromosome segregation during both mitosis and meiosis. It consists of survivin, borealin, inner centromere protein, and Aurora kinase B or C. We confirm the absence of Aurora kinase C in marsupials and show its absence in both platypus and echidna, which supports the current model of the evolution of Aurora kinases. High expression of AURKBC, an ancestor of AURKB and AURKC present in monotremes, suggests that this gene is performing all necessary meiotic functions in monotremes. Other genes of the chromosome passenger complex complex are present and conserved in monotremes, suggesting that their function has been preserved in mammals. Cohesins are another family of genes that are of vital importance for chromosome cohesion and segregation at mitosis and meiosis. Previous work has demonstrated an accumulation and differential loading of structural maintenance of chromosomes 3 (SMC3) on the platypus sex chromosome complex at meiotic prophase I. We investigated if a similar accumulation occurs in the echidna during meiosis I. In contrast to platypus, SMC3 was only found on the synaptonemal complex in echidna. This indicates that the specific distribution of SMC3 on the sex chromosome complex may have evolved specifically in platypus.Filip Pajpach, Linda Shearwin-Whyatt and Frank Grützne

Elektrophile Alkylierungen von Norbornen - Synthese 7-substituierter Norbornene

Die Lewis-Säure-katalysierte Addition SN1-reaktiver Alkylhalogenide 2 an Norbornen liefert syn-7-Alkyl-exo-2-halogennorbornane 3 neben geringen Mengen der anti-Isomeren 9. Bei der Behandlung von 3 mit Kalium-tert-butoxid erhält man die syn-7-substituierten Norbornene 4, die zu all-cis-1,2,3-trisubstituierten Cyclopentanen oxidiert werden können