Effects of UV-radiation on feeding behavior in Dendrobates tinctorius

UV-B levels have recently been increasing with the depletion of the ozone layer. Recent data have shown that amphibians are especially susceptible to UV-B, with poison dart frogs being one focus in these studies. The purpose of this study was to determine if UV-B radiation affects the foraging behavior of poison dart frogs. This study was conducted with a captive population of juvenile Dendrobates tinctorius at Pepperdine University in Malibu, California. Frogs underwent one of three treatments: UV only, Food only, and UV and Food. UV only trials were conducted using two UV lights emitting approximately 1.2 uW/cm2 of UV total on one side of the box and two identical off lights on the other side. Food only trials used flightless fruit flies in small petri dishes and empty petri dishes as control. The UV and Food trials combined these methods with the UV light over the fruit flies. The data showed that for the UV only trials, the frogs were on the UV side 39.5% of the time, indicating UV avoidance, and for the Food only trials, they were on the food only side 63.5% of the time, indicating food interest. The UV and Food frogs spent 26.9% of their time on the treatment side. We can conclude that frogs avoided feeding when the area near the food source was also exposed to low levels of UV radiation and therefore UV radiation has an effect on foraging behavior in frogs. Diurnal tropical dart frogs must balance many demands in the wild including the avoidance of even low levels of UV radiation from the sun

EXAFS study of nickel tetracarbonyl and nickel clusters in zeolite Y

Adsorption and thermal decomposition of Ni(CO)4 in the cage system of zeolite Y have been studied with EXAFS, electron microscopy and IR spectroscopy , Ni(CO)4 is adsorbed as an intact molecule in both cation - free zeolite Y and NaY. Symmetry changes of the molecule in NaY are assigned to the formation of Na—OC-IMi bridges. Thermal treatment of the Ni(CO)4/NaY adduct leads to loss of CO concomitant with the formation of a binodal Ni phase. A major part of the forms clusters with diameter between 0.5 and about 1.5 nm, in addition to larger crystallites (5-30 nm), sticking at the outer surface of the zeolite matrix., The Ni-Ni scattering amplitude indicates increasing average particle size with increasing temperature

Word order variation in Makua : a phrase structure grammar analysis

LoC Class: PL8483.1, LoC Subject Headings: Makhuwa language--Gramma

Structural disorder, magnetism, and electrical and thermoelectric properties of pyrochlore Nd2Ru2O7

Polycrystalline Nd2Ru2O7 samples have been prepared and examined using a combination of structural, magnetic, and electrical and thermal transport studies. Analysis of synchrotron X-ray and neutron diffraction patterns suggests some site disorder on the A-site in the pyrochlore sublattice: Ru substitutes on the Nd-site up to 7.0(3)%, regardless of the different preparative conditions explored. Intrinsic magnetic and electrical transport properties have been measured. Ru 4d spins order antiferromagnetically at 143 K as seen both in susceptibility and specific heat, and there is a corresponding change in the electrical resistivity behaviour. A second antiferromagnetic ordering transition seen below 10 K is attributed to ordering of Nd 4f spins. Nd2Ru2O7 is an electrical insulator, and this behaviour is believed to be independent of the Ru-antisite disorder on the Nd site. The electrical properties of Nd2Ru2O7 are presented in the light of data published on all A2Ru2O7 pyrochlores, and we emphasize the special structural role that Bi3+ ions on the A-site play in driving metallic behaviour. High-temperature thermoelectric properties have also been measured. When considered in the context of known thermoelectric materials with useful figures-of-merit, it is clear that Nd2Ru2O7 has excessively high electrical resistivity which prevents it from being an effective thermoelectric. A method for screening candidate thermoelectrics is suggested.Comment: 19 pages, 10 figure

Analysis of the NASA shuttle hypervelocity impact database

A statistical analysis of the NASA Space Shuttle Hypervelocity Impact Database to find correlations between meteoroid and orbital debris (M/OD) impacts on the shuttle orbiter fleet and specific mission parameters; Inclination, Altitude, Duration and Year. M/OD impact data, regardless of location, particle type or mission was examined first, followed by the subcategories of Window data, Radiator data, Reinforced Carbon-Carbon (RCC) data, and Flexible Reusable Surface Insulation (FRSI) data. In an effort to characterize and evaluate the meteoroid and orbital debris (M/OD) environment in low earth orbit, post-flight surveys of the shuttle orbiters are conducted to identify damage caused by hypervelocity impacts from M/OD. Survey analysis determines whether the impactor was a naturally occurring meteoroid or man-made orbital debris, as well as the impactor's size and impact velocity. From the post-flight survey data, calculations on the number of impacts from specific particle diameters or specific particle materials are made and compared to mission parameters to help engineers design spacecraft for better mission efficiency by reducing the effects of M/OD impacts. This thesis analyzes the NASA Space Shuttle Hypervelocity Impact Database, using regression analysis software, to find correlations between M/OD impacts on the shuttle orbiter fleet and mission parameters to draw conclusions on what is influencing vehicle damage.http://archive.org/details/analysisofnasash109456265Lieutenant, United States NavyApproved for public release; distribution is unlimited

Single-cell transcriptomes reveal the mechanism for a breast cancer prognostic gene panel.

The clinical benefits of the MammaPrint® signature for breast cancer is well documented; however, how these genes are related to cell cycle perturbation have not been well determined. Our single-cell transcriptome mapping (algorithm) provides details into the fine perturbation of all individual genes during a cell cycle, providing a view of the cell-cycle-phase specific landscape of any given human genes. Specifically, we identified that 38 out of the 70 (54%) MammaPrint® signature genes are perturbated to a specific phase of the cell cycle. The MammaPrint® signature panel derived its clinical prognosis power from measuring the cell cycle activity of specific breast cancer samples. Such cell cycle phase index of the MammaPrint® signature suggested that measurement of the cell cycle index from tumors could be developed into a prognosis tool for various types of cancer beyond breast cancer, potentially improving therapy through targeting a specific phase of the cell cycle of cancer cells

Not ‘Islands, Entire of Themselves’: Exploring the Spatial Context of City-level Robbery Rates

The current study examines spatial dependence in robbery rates for a sample of 1,056 cities with 25,000 or more residents over the 2000–2003 period. Although commonly considered in some macro-level research, spatial processes have not been examined in relation to city-level variation in robbery. The results of our regression analyses suggest that city robbery rates are not spatially independent. We find that spatial dependence is better accounted for by spatial error models than by spatial lag models. Further exploration of various spatial weights matrices indicates that robbery rates of cities within the same state are related to robbery rates of other cities within the same state, regardless of their proximity. Our analyses illustrate how systematic inquiry into spatial processes can alert researchers to important omitted variable biases and identify intriguing problems for future research

Natural gas cost for evaluating energy resource opportunities at Fort Stewart

Ft. Stewart, a United States Army Forces Command (FORSCOM) installation located near Hinesville, Georgia, is currently undergoing an evaluation of its energy usage, which is being performed by Pacific Northwest Laboratory. In order to examine the energy resource opportunities (EROs) at Ft. Stewart, marginal fuel costs must be calculated. The marginal, or avoided, cost of gas service is used in conjunction with the estimated energy savings of an ERO to calculate the dollar value of those savings. In the case of natural gas, the costing becomes more complicated due to the installation of a propane-air mixing station. The propane-air station is being built under a shared energy savings (SES) contract. The building of a propane-air station allows Ft. Stewart to purchase natural gas from their local utility at an interruptible rate, which is lower than the rate for contracting natural gas on a firm basis. The propane-air station will also provide Ft. Stewart with fuel in the event that the natural gas supply is curtailed. While the propane-air station does not affect the actual cost of natural gas, it does affect the cost of services provided by gas. Because the propane-air station and the SES contract affect the cost of gas service, they must be included in the analysis. Our analysis indicates a marginal cost of gas service of 30.0 cents per therm, assuming a total propane usage by the mixing station of 42,278 gallons (38,600 therms) annually. Because the amount of propane that may be required in the event of a curtailment is small relative to the total service requirement, variations in the actual amount should not significantly affect the cost per therm

Persistence of intense, climate-driven runoff late in Mars history

Mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet’s surface. These rivers’ existence is a challenge to models of planetary climate evolution. We report results indicating that, for a given catchment area, rivers on Mars were wider than rivers on Earth today. We use the scale (width and wavelength) of Mars paleo-rivers as a proxy for past runoff production. Using multiple methods, we infer that intense runoff production of >(3–20) kg/m 2 per day persisted until 1 Ga. Our improved history of Mars’ river runoff places new constraints on the unknown mechanism that caused wet climates on Mars