Laboratory CO2 photolysis studies related to planetary atmospheres

The CO(a 3II) state, the upper state of the Cameron bands, was characterized with respect to its average radiative lifetime and its quenching coefficients for a series of simple molecules. The CO2 recombination reaction (O(3P) + CO + M yields CO2 + M) was studied as a function of temperature. For M = CO, the rate constant can be expressed as k = 6.5 x 10/33 exp(-4340 plus or minus 550/RT) cm to the 6th power molec/2 sec/1, whereas the rate for M = CO2, the pertinent species in the planetary atmospheres, is 1.6 times greater. The quantum yield for CO2 photodissociation was measured in the 1200-1500 A region, using atomic line sources. The yield throughout this spectral region was much lower than that measured at 1470 A, the lowest value obtained being 8% at 1304 A

The source of stratospheric NO and N2O

The photodissociation of O3 was investigated as a possible sources of N2O production in the stratosphere. Photolysis was conducted at 1576 A to generate the excited O2 states that react with N2 to form N2O. At this wavelength, there is a quantum yield of two for prompt production of oygen atoms, which is a consequence of the existence of two photodissociative channels giving comparable yields. One of these channels gives O(D1) and O2(b1sigma(+)subg), with a quantum yield of 0.6, whereas the other results in fragmentation of the O3, with production of three ground state oxygen atoms. The O2(b) is generated with vibrational excitation, and there are comparable populations in levels O to 3. These observations are the first to show O2(b) production from any photodissociative process, and were made under conditions in which the kinetics of vibrationally excited O2(b) can be studied. It appears that O3 photodissociation at 1576 A is not a good system for generating the higher electronic states of O2; it is likely that better results will be obtained at 1930 A

Laboratory CO2 photolysis studies related to planetary atmospheres Semiannual report, 15 Jul. 1969 - 15 Jan. 1970

Oxygen and carbon dioxide UV photolysis studied with resonance fluorescence to analyze planetary atmospheric processe

Photodissociation of CO2 and quenching of metastables

Investigations in four different areas were carried out to further our understanding of the chemistry of the atmospheres of Mars and Venus. CO2 photodissociation quantum yields were determined in the 1300-1500 A spectral region by measuring both CO and oxygen atoms. The O(1S) quantum yield was determined for CO2 photodissociation in the 1060-1175 A spectral region. The measurement resolves the differences between two earlier experiments, and demonstrates that the O(1S) yield is unity throughout most of the measured region. The pathways for the quenching of O(1S) by N2O, CO2, H2O and NO were investigated and the source of the Venus nightglow, detected by Venera 9 and 10, was investigated. What appears to be a new O2 band system, was detected although the identity of the transition is not yet evident

Studying Atomic Physics Using the Nighttime Atmosphere as a Laboratory

A summary of our recent work using terrestrial nightglow spectra, obtained from astronomical instrumentation, to directly measure, or evaluate theoretical values for fundamental parameters of astrophysically important atomic lines

Venus O2 night glow observations with VIRTSI/Venus Express

International audienc

A study of teacher perceptions of the use of student growth measures in teacher evaluation and its effect on school culture

This study explored teacher perceptions of the inclusion of student growth data into the teacher evaluation process and the relationship(s) these perceptions might have on school culture. A positive correlation (p \u3c.001) was found between the inclusion of VAM into the teacher evaluation process and motivation to collaborate. Key findings include participants working in priority designated schools were less likely to collaborate; participants with more knowledge about VAM had more positive perceptions; and participants in nonurban schools or smaller schools had more positive perceptions of VAM. Significant main effects for urban location (p = .001), number of teachers (p = .005), and level of knowledge (p = .05) were found. Participants in priority or urban schools indicated they don’t want to collaborate at a higher level than their counterparts in non-priority or nonurban schools. The inclusion of VAM appears to lead participants into isolation, not necessarily competitive relationships

Understanding the role of maternal-fetal tissue communication in the evolution of genomic imprinting and disruption of placental development

Understanding the role of maternal-fetal tissue communication in the evolution of genomic imprinting and disruption of placental development Ashlin Slanger¹, John Statz¹, Fernando Rodriguez¹, Jeff Good¹ ¹Division of Biological Sciences, University of Montana The placenta is a fast-evolving organ in mammals and has been hypothesized to be a hotspot for the evolution of genomic imprinting. Imprinted expression is a form of gene regulation by which some genes show parent-of-origin dependent allelic expression bias and is critical for successful mammalian development. Studies of placental gene expression in hybridizations between mouse species have shown disruption of placental expression in several genes including a subset of imprinted genes, consistent with a role in the emergence of reproductive incompatibilities between species. Three of the genes that show imprinted and disrupted expression levels in hybrids (Erv3, Mfap5, and Edn2) are preferentially expressed in the endocrine layer of the placenta and code for signaling proteins associated with maternal immunomodulation, making them candidates for the regulation of communication between maternal and fetal tissues. We designed an in situ hybridization experiment to gain insights into the role of these genes during development with the goal to explore the genetic placental disruption in hybrid crosses. We compared spatiotemporal patterns of placental expression of the three candidate genes in interspecies hybrids to control (non-hybrid) mice at three developmental time points of mouse embryonic development. To test the hypothesis that these genes participate in the regulation of maternal-fetal communication, we are comparing spatiotemporal expression patterns between these candidate genes and the prolactin gene (Prl3a1) known to be expressed in the endocrine layer of the placenta and mediate maternal-fetal communication during mice placental development. We are currently analyzing samples from our control cross using in situ hybridization and sampling additional tissues from interspecies hybrids. This study will provide novel insights into the role of imprinted expression in modulating maternal-fetal communication in the placenta, advancing the current understanding of placental biology and its role in the origin of species

Laboratory CO2 photolysis studies related to planetary atmospheres Final report, 15 Jul. 1969 - 15 Jul. 1970

Photolysis of CO-2 in UV spectral region applied to models of Martian and Venusian atmosphere