Multicolor pyrometer for materials processing in space

This report documents the work performed by Physical Sciences Inc. (PSI), under contract to NASA JPL, during a 2.5-year SBIR Phase 2 Program. The program goals were to design, construct, and program a prototype passive imaging pyrometer capable of measuring, as accurately as possible, and controlling the temperature distribution across the surface of a moving object suspended in space. These goals were achieved and the instrument was delivered to JPL in November 1989. The pyrometer utilizes an optical system which operates at short wavelengths compared to the peak of the black-body spectrum for the temperature range of interest, thus minimizing errors associated with a lack of knowledge about the heated sample's emissivity. To cover temperatures from 900 to 2500 K, six wavelengths are available. The preferred wavelength for measurement of a particular temperature decreases as the temperature increases. Images at all six wavelengths are projected onto a single CCD camera concurrently. The camera and optical system have been calibrated to relate the measured intensity at each pixel to the temperature of the heated object. The output of the camera is digitized by a frame grabber installed in a personal computer and analyzed automatically to yield temperature information. The data can be used in a feedback loop to alter the status of computer-activated switches and thereby control a heating system

DNA crosslinking and biological activity of a hairpin polyamide–chlorambucil conjugate

A prototype of a novel class of DNA alkylating agents, which combines the DNA crosslinking moiety chlorambucil (Chl) with a sequence-selective hairpin pyrrole-imidazole polyamide ImPy-beta-ImPy-gamma-ImPy-beta-Dp (polyamide 1), was evaluated for its ability to damage DNA and induce biological responses. Polyamide 1-Chl conjugate (1-Chl) alkylates and interstrand crosslinks DNA in cell-free systems. The alkylation occurs predominantly at 5'-AGCTGCA-3' sequence, which represents the polyamide binding site. Conjugate-induced lesions were first detected on DNA treated for 1 h with 0.1 muM 1-Chl, indicating that the conjugate is at least 100-fold more potent than Chl. Prolonged incubation allowed for DNA damage detection even at 0.01 muM concentration. Treatment with 1-Chl decreased DNA template activity in simian virus 40 (SV40) in vitro replication assays. 1-Chl inhibited mammalian cell growth, genomic DNA replication and cell cycle progression, and arrested cells in the G(2)/M phase. Moreover, cellular effects were observed at 1-Chl concentrations similar to those needed for DNA damage in cell-free systems. Neither of the parent compounds, unconjugated Chl or polyamide 1, demonstrated any cellular activity in the same concentration range. The conjugate molecule 1-Chl possesses the sequence-selectivity of a polyamide and the enhanced DNA reactivity of Chl

Molecular Studies to Evaluate Variegation of Philodendron var. Birkin - Are Genetic Mutations Responsible for Variegation in Philodendron Birkin?

Plant tissue culture and molecular genetic techniques were used to analyze the instability of the genome in philodendron var. \u27Birkin\u27. This plant has variegated, white, green, and greenish-red leaves (that have lost their variegation) on the same plant. Did genetic mutations occur in meristematic sectors of variegated leaves that have reverted to green coloration, or is it an epigenetic change?  PCR and sets of RAPD plastid primers were used to determine if the presence or absence of a PCR product correlated with differences in leaf color and variegation (white, green-white, variegated, reddish green or green leaves). A DNA isolation procedure was optimized to extract PCR-quality plastid DNA from Philodendron leaves. A modified DNA extraction procedure (BABEC) was used to isolate plastid DNA. It resulted in a high yield of DNA as measured by the Nanodrop system. PCR was performed with eight different RAPD plastid primers (GB07, GB8, OPA19, OPA22, OPB22, OPC08, OPC12, RAPD primer #1, RAPD primer #2). Differences in PCR products were observed for five primers, while two primers resulted in no difference in PCR products. This indicated that genetic mutations resulted in differences in leaf color and variegation. We are not excluding the possibility that epigenetic changes also play a role in variegation, however, this has not yet been analyzed. These results could prove useful for breeding ornamental traits and introducing improvements into the genus Philodendron

Development of a Tool to Recreate the Mars Science Laboratory Aerothermal Environment

The Mars Science Laboratory will enter the Martian atmosphere in 2012 with multiple char depth sensors and in-depth thermocouples in its heatshield. The aerothermal environment experienced by MSL may be computationally recreated using the data from the sensors and a material response program, such as the Fully Implicit Ablation and Thermal (FIAT) response program, through the matching of the char depth and thermocouple predictions of the material response program to the sensor data. A tool, CHanging Inputs from the Environment of FIAT (CHIEF), was developed to iteratively change different environmental conditions such that FIAT predictions match within certain criteria applied to an external data set. The computational environment is changed by iterating on the enthalpy, pressure, or heat transfer coefficient at certain times in the trajectory. CHIEF was initially compared against arc-jet test data from the development of the MSL heatshield and then against simulated sensor data derived from design trajectories for MSL. CHIEF was able to match char depth and in-depth thermocouple temperatures within the bounds placed upon it for these cases. Further refinement of CHIEF to compare multiple time points and assign convergence criteria may improve accuracy

Litigation: Time to Revisit \u3cem\u3eChevron\u3c/em\u3e Deference?

This panel discussion took place on Thursday, November 13, 2014 at the Mayflower Hotel in Washington, D.C., prior to the passing of Justice Antonin Scalia. Justice Scalia\u27s impact on the development of administrative law in the United States is unparalleled

Increasing Underrepresented Scientists in Cancer Research: The UCSD CURE Program

The Moores UCSD Cancer Center’s Continuing Umbrella of Research Experiences program aims to increase the number of underrepresented students pursuing careers in cancer research, cancer care, and health disparities research. Participants receive 8 weeks of laboratory and classroom training during the summer followed by participation in research mentors’ laboratories. Of the 82 CURE students accrued (2002 and 2008), 91% persisted in science after 1 year. Of the 63 students eligible to graduate in 2009, 7 had dropped out of college; 56 graduated. Of the graduates, 98% were science majors and 61% (34) had already matriculated to graduate or health professional schools for cancer research and clinical care careers