Using LabVIEW to Synchronize an Infrared Diode Laser Spectrometer with a Pulsed Supersonic Jet Expansion

We describe software developed with LabVIEW to provide operational control for an in-house infrared diode laser spectrometer that has been combined with a pulsed supersonic jet expansion sample source. Data were collected with this instrument using a modified version of the rapid-scanning method. A prerequisite in employing the rapid-scan detection scheme is that the modulation used to scan the laser be synchronized in time with the electrical signal used to trigger the pulsed gas valve. Software performance was evaluated by examining a series of rotation vibration (ro-vibrational) spectra for the carbon monoxide molecule in the five micron region of the infrared

Evapotranspiration from Spider and Jade Plants Can Improve Relative Humidity in an Interior Environment

Citation: Kerschen, E., Garten, C., Williams, K., & Derby, M. (2016). Evapotranspiration from Spider and Jade Plants Can Improve Relative Humidity in an Interior Environment. HortTechnology, 26(6), 803-810. doi: 10.21273/HORTTECH03473-16Plants in the interiorscape have many documented benefits, but their potential for use in conjunction with mechanical heating, ventilation, and air conditioning (HVAC) systems to humidify dry indoor environments requires more study. In this research, evaporation and evapotranspiration rates for a root medium control, variegated spider plants (Chlorophytum comosum), and green jade plants (Crassula argentea) were measured over 24 hours at 25% and 60% relative humidity (RH) and 20 °C to generate data for calculation of the leaf surface area and number of plants necessary to influence indoor humidity levels. Evaporation and evapotranspiration rates were higher for all cases at 25% RH compared with 60% RH. At 25% RH during lighted periods, evapotranspiration rates were ?15 g·h?1 for spider plants and 8 g·h?1 for jade plants. Spider plants transpired during lighted periods due to their C3 photosynthetic pathway, whereas jade plants had greater evapotranspiration rates during dark periods—about 11 g·h?1—due to their crassulacean acid metabolism (CAM) photosynthetic pathway. A combination of plants with different photosynthetic pathways (i.e., C3 and CAM combination) could contribute to greater consistency between evapotranspiration rates from day to night for humidification of interior spaces. Using the measured data, calculations indicated that 32,300 cm2 total spider plant leaf surface area, which is 25 spider plants in 4-inch-diameter pots or fewer, larger plants, could increase the humidity of an interior bedroom from 20% RH to a more comfortable 30% RH under bright interior light conditions

Low Temperature Performance of Bio-Derived/Chemical Additives in Warm Mix Asphalt

Corn and soy based bio-derived warm mix asphalt (WMA) additives are currently being developed. In the past, additives with similar properties have been shown to successfully reduce the mixing and compaction temperatures of asphalt by as much as 30°C. Isosorbide distillation bottoms (IDB), a WMA additive, is a co-product from the conversion of sorbitol to isosorbide, where sorbitol is derived by hydrogenating glucose from corn biomass. Past research utilizing IDB at several dosage rates showed there was improvement in low temperature binder performance using the bending beam rheometer (BBR) between dosage rates of 0.5% and 1.0% by weight of the binder. This research investigates whether low temperature improvement occurs with several new bio-derived material additives that have similar properties to materials used in past research, as well as compares their performance to two commercially available/bio-derived WMA additives from the forest products industry. In cold regions of the United States, the main observed distress in asphalt pavements is low temperature cracking. Characterization of binder performance at low temperature is possible with the use of the BBR. For asphalt mixtures, characterization is more challenging at low temperatures due to the response from the aggregate phase of a mixture. To examine low temperature performance of hot mix asphalt (HMA) and WMA, the semi-circular bend (SCB) test was used to characterize the fracture properties. SCB tests showed that additive choice was a statistically significant factor in fracture energy properties but not for stiffness and fracture toughness. All of the new additives were successfully used at reduced mixing and compaction temperatures and did not adversely impact low temperature mix fracture properties of WMA when compared against the control HMA. However, improvement of fracture energy was observed when comparing the epoxidized esterified fatty acid additive to the other five additives used in this work

Computational identification of Drosophila microRNA genes

BACKGROUND: MicroRNAs (miRNAs) are a large family of 21-22 nucleotide non-coding RNAs with presumed post-transcriptional regulatory activity. Most miRNAs were identified by direct cloning of small RNAs, an approach that favors detection of abundant miRNAs. Three observations suggested that miRNA genes might be identified using a computational approach. First, miRNAs generally derive from precursor transcripts of 70-100 nucleotides with extended stem-loop structure. Second, miRNAs are usually highly conserved between the genomes of related species. Third, miRNAs display a characteristic pattern of evolutionary divergence. RESULTS: We developed an informatic procedure called 'miRseeker', which analyzed the completed euchromatic sequences of Drosophila melanogaster and D. pseudoobscura for conserved sequences that adopt an extended stem-loop structure and display a pattern of nucleotide divergence characteristic of known miRNAs. The sensitivity of this computational procedure was demonstrated by the presence of 75% (18/24) of previously identified Drosophila miRNAs within the top 124 candidates. In total, we identified 48 novel miRNA candidates that were strongly conserved in more distant insect, nematode, or vertebrate genomes. We verified expression for a total of 24 novel miRNA genes, including 20 of 27 candidates conserved in a third species and 4 of 11 high-scoring, Drosophila-specific candidates. Our analyses lead us to estimate that drosophilid genomes contain around 110 miRNA genes. CONCLUSIONS: Our computational strategy succeeded in identifying bona fide miRNA genes and suggests that miRNAs constitute nearly 1% of predicted protein-coding genes in Drosophila, a percentage similar to the percentage of miRNAs recently attributed to other metazoan genomes

Laser-Induced Damage And The Role Of Self-Focusing

We review the influence of self-focusing on the measurement of bulk laser-induced-damage (LID) thresholds in normally transparent optical mate-rials. This role is experimentally determined by measuring the spot size and polarization dependence of LID and by observing beam distortion in the far field. Utilizing these techniques, we find that by using a tight focusing geometry in which the breakdown power is below P2, the effects of self-focusing can be practically eliminated in an LID experiment. P2 is the so-called second critical power for self-focusing, and P2 = 3.77P1, where P1 = cX2/327r2n2, where c is the speed of light in vacuum, X is the laser wavelength and n2 is the nonlinear index of refraction. This is in accordance with numerical calculations by J. H. Marburger [in Progress in Quantum Electronics, J. H. Sanders and S. Sten-holm, eds., Vol. 4, Part 1, pp. 35-110, Pergamon, Oxford (1975)]. With this knowledge we determine that damage is only partially explained by avalanche ionization and that the initiation of damage is strongly influenced by extrinsic processes. We therefore conclude that we are measuring extrinsic LID

Development of Bio-Based Polymers for Use in Asphalt

Asphalt binder is typically modified with poly type (styrene-butadiene-styrene or SBS) polymers to improve its rheological properties and performance grade. The elastic and principal component of SBS polymers is butadiene. For the last decade, butadiene prices have fluctuated and significantly increased, leading state highway agencies to search for economically viable alternatives to butadiene based materials. This project reports the recent advances in polymerization techniques that have enabled the synthesis of elastomeric, thermoplastic, block-copolymers (BCPs) comprised of styrene and soybean oil, where the “B” block in SBS polymers is replaced with polymerized triglycerides derived from soybean oil. These new breeds of biopolymers have elastomeric properties comparable to well-established butadiene-based styrenic BCPs. In this report, two types of biopolymer formulations are evaluated for their ability to modify asphalt binder. Laboratory blends of asphalt modified with the biopolymers are tested for their rheological properties and performance grade. Blends of asphalt modified with the biopolymers are compared to blends of asphalt modified with two commonly used commercial polymers. The viscoelastic properties of the blends show that biopolymers improve the performance grade of the asphalt to a similar and even greater extent as the commercial SBS polymers. Results shown in this report indicate there is an excellent potential for the future of these biopolymers as economically and environmentally favorable alternatives to their petrochemically-derived analogs

Dendritic Targeting in the Leg Neuropil of Drosophila: The Role of Midline Signalling Molecules in Generating a Myotopic Map

During development of the Drosophila motor system, global guidance cues control and coordinate the targeting of both input and output elements of the neural system

Integrating physiology into correlative models can alter projections of habitat suitability under climate change for a threatened amphibian

Rapid global change has increased interest in developing ways to identify suitable refu-gia for species of conservation concern. Correlative and mechanistic species distribu-tion models (SDMs) represent two approaches to generate spatially-explicit estimates of climate vulnerability. Correlative SDMs generate distributions using statistical associations between environmental variables and species presence data. In contrast, mechanistic SDMs use physiological traits and tolerances to identify areas that meet the conditions required for growth, survival and reproduction. Correlative approaches assume modeled environmental variables influence species distributions directly or indirectly; however, the mechanisms underlying these associations are rarely verified empirically. We compared habitat suitability predictions between a correlative-only SDM, a mechanistic SDM and a correlative framework that incorporated mechanis-tic layers (‘hybrid models’). Our comparison focused on green salamanders Aneides aeneus, a priority amphibian threatened by climate change throughout their disjunct range. We developed mechanistic SDMs using experiments to measure the thermal sensitivity of resistance to water loss (ri) and metabolism. Under current climate con-ditions, correlative-only, hybrid and mechanistic SDMs predicted similar overlap in habitat suitability; however, mechanistic SDMs predicted habitat suitability to extend into regions without green salamanders but known to harbor many lungless salaman-ders. Under future warming scenarios, habitat suitability depended on climate sce-nario and SDM type. Correlative and hybrid models predicted a 42% reduction or 260% increase in area considered to be suitable depending on the climate scenario. In mechanistic SDMs, energetically suitable habitat declined with both climate scenarios and was driven by the thermal sensitivity of ri. Our study indicates that correlative-only and hybrid approaches produce similar predictions of habitat suitability; however, discrepancies can arise for species that do not occupy their entire fundamental niche, which may hold consequences of conservation planning of threatened species