Quantification of food intake in Drosophila

Measurement of food intake in the fruit fly Drosophila melanogaster is often necessary for studies of behaviour, nutrition and drug administration. There is no reliable and agreed method for measuring food intake of flies in undisturbed, steady state, and normal culture conditions. We report such a method, based on measurement of feeding frequency by proboscis-extension, validated by short-term measurements of food dye intake. We used the method to demonstrate that (a) female flies feed more frequently than males, (b) flies feed more often when housed in larger groups and (c) fly feeding varies at different times of the day. We also show that alterations in food intake are not induced by dietary restriction or by a null mutation of the fly insulin receptor substrate chico. In contrast, mutation of takeout increases food intake by increasing feeding frequency while mutation of ovoD increases food intake by increasing the volume of food consumed per proboscis-extension. This approach provides a practical and reliable method for quantification of food intake in Drosophila under normal, undisturbed culture conditions

How successful have lobbyists been at influencing state and national policy to further the completion of the Dakota Access Pipeline, since the 2008 US Election?

This study sets out to investigate a contemporary example of lobbying, by enquiring as to whether lobbyists have successfully influenced state and national policy which furthered the completion of the Dakota Access Pipeline since 2008. This involves an analysis of campaign contributions made to key federal candidates by organisations related to the pipeline. The results of this analysis, suggests that lobbyists have been highly successful in influencing policy which led to the completion of the pipeline. The data collected in this study, highlights lobbyists use of "natural allies" with "proximate objectives" (Hall and Deardoff 2006, p.69), creating a network of allies, to enable the completion of the pipeline. The study raises concerns over the nature of President Trump's relationship with the 'Energy Transfer Partners' CEO, Kelcy Warren. Campaign funding and apparent conflicts of interest at state and national level and their impact on the democratic process are explored, including whether President Trump's personal investments may have played a significant role in influencing his policy decisions concerning the pipeline. This study helps provide an insight into modern lobbying, revealing the power and influence money, through campaign finance, has in the democratic system

Processing of transcripts of a dimeric tRNA gene in yeast uses the nuclease responsible for maturation of the 3′ termini upon 5 S and 37 S precursor rRNAs

AbstractThe rna82 mutation of Saccharomyces cerevisiae inactivates an RNA processing activity responsible for maturation of 3′-terminal sequences upon 5 S and 37 S ribosomal RNA precursors. This study describes a difference in the processing of transcripts of an S. cerevisiae dimeric tRNA gene (tRNAArg-tRNAAsp) in RNA polymerase III in vitro transcription extracts prepared from rna82 and wild-type cells. The mutant extract accumulated additional processing intermediates containing tRNAArg sequences as compared to the extract from wild-type cells. The structure of these intermediates revealed a defect in removal of the 10 nucleotides left 3′ to the tRNAArg sequence by the RNase P cleavage immediately 5′ to tRNAAsp. This is the first demonstration of a mutational defect affecting maturation of 3′ sequences upon a eukaryotic tRNA precursor

The gravitational wave rocket

Einstein's equations admit solutions corresponding to photon rockets. In these a massive particle recoils because of the anisotropic emission of photons. In this paper we ask whether rocket motion can be powered only by the emission of gravitational waves. We use the double series approximation method and show that this is possible. A loss of mass and gain in momentum arise in the second approximation because of the emission of quadrupole and octupole waves.Comment: 10 pages LaTe

SKINTRONICS: Wireless, Skin-Wearable Electronics for Monitoring of Electrocardiogram

The ECGs I micro-fabricate are designed to be flexible, stretchable and wireless circuits that can be applied to the skin directly. The device is encased in a conformal, silicon-like substrate, that allows the ECG to be attached with the electrodes. Each electrode has been previously measured and verified that it will be correctly placed for an accurate reading. Prototyping this ECG/electrode device allows the user to mount the prototype directly to the patient without having to attach and wire ten other electrodes. This prototype solves the issue that comes about when a doctor, nurse or emergency medical technician must attach a traditional 12-lead ECG that requires sufficient knowledge and experience to place each electrode accurately and precisely in order to achieve an accurate reading. In my fabricated device, the ECG is wired directly to the three most crucial electrodes placed at V2, V3 and V4 based on the traditional precordial electrode placement for a 12-lead ECG. By covering these three positions, my research team and I can ensure we achieve an accurate reading, and will find the correct placement due to the compact design with pre-placed electrodes. Another benefit of this prototype is its flexibility. This allows the circuit to be more durable when being picked-up, transferred to the patient, and then removed; this may also allow for multiple applications whereas conventional electrodes can only be used once. This prototype is currently in the preliminary stages of testing and will hopefully be implemented into medical practice in the future.https://scholarscompass.vcu.edu/uresposters/1245/thumbnail.jp

Common Loons Respond Adaptively to a Black Fly that Reduces Nesting Success

Nesting birds must often cope with harassment from biting insects, but it is difficult to ascertain what effect such pests might have on breeding success and population dynamics. We tested the hypothesis that a black fly (Simulium annulus) that feeds on the blood of nesting Common Loons (Gavia immer) causes nest abandonment in this charismatic diving bird. In addition, we measured effects of fly-induced abandonment on a loon population, and examined potential predictors of fly abundance and nest abandonment. We also tested a second hypothesis, which holds that loon pairs that abandon a nest owing to flies should often remain at the site for their subsequent nesting attempt, since fly outbreaks last only 1–2 weeks. All predictions of the fly-induced abandonment hypothesis were supported, including strong correlations between fly counts and rate of abandonment, reduced incubation during severe fly years, and increased abandonment during cool springs, which promote longevity of the flies. The correlation between nest abandonment and population breeding success suggests that S. annulus reduced the chick fledging rate by as much as 23% in a year of severe infestation. Fly numbers on loons and their nests were highest when temperatures were high and winds were light. Surprisingly, however, exposure to the prevailing wind increased, not decreased, nest abandonment, perhaps because of wave action. Lake size was inversely and female age directly correlated with abandonment rate, possibly due to food limitation in small lakes and senescence of females, respectively. Finally, pairs that abandoned a first nest renested at the same site with much greater frequency than did pairs that lost eggs to a predator, indicating that loons are capable of responding adaptively to a cause of nest failure that is time- but not space-dependent