The effect of caffeine mouth rinse on self-paced cycling performance

The aim of the study was to determine whether caffeine mouth rinse would improve 30 min self-paced cycling trial. Twelve healthy active males (age 20.5±0.7 years, mass 87.4±18.3 kg) volunteered for the study. They attended the laboratory on 3 separate occasions performing a 30 min self-paced cycling trial. On one occasion water was given as a mouth rinse for 5 s (PLA), on another occasion a 6.4% maltodextrin (CHO) solution was given for 5 s and finally a caffeine solution (containing 32 mg of caffeine dissolved in 125 ml water; CAF) was given for 5 s. Distance cycled, heart rate, ratings of perceived exertion, cadence, speed and power output were recorded throughout all trials. Distance cycled during the CAF mouth rinse trial (16.2±2.8 km) was significantly greater compared to PLA trial (14.9±2.6 km). There was no difference between CHO and CAF trials (P=0.89). Cadence, power and velocity were significantly greater during the CAF trial compared to both PLA and CHO (P0.05). Caffeine mouth rinse improves 30 min cycling performance by allowing the participant to increase cadence, power and velocity without a concurrent increase in perceived exertion and heart rate

Alterations in Mosquito Behaviour by Malaria Parasites: Potential Impact on Force of Infection

A variety of studies have reported that malaria parasites alter the behaviour of mosquitoes. These behavioural alterations likely increase transmission because they reduce the risk of vector death during parasite development and increase biting after parasites become infectious. A mathematical model is used to investigate the potential impact of these behavioural alterations on the lifetime number of infectious bites delivered. The model is used to explore the importance of assumptions about the magnitude and distribution of mortality as well as the importance of extrinsic incubation period and gonotrophic cycle length. Additionally, the model is applied to four datasets taken from actual transmission settings. The impact of behavioural changes on the relative number of lifetime bites is highly dependent on assumptions about the distribution of mortality over the mosquito-feeding cycle. Even using fairly conservative estimates of these parameters and field collected data, the model outputs suggest that altered feeding could easily cause a doubling in the force of infection.Infection-iduced behavioural alterations have their greatest impact on the lifetime number of infectious bites in environments with high feeding-related adult mortality and many pre-infectious feeding cycles. Interventions that increase feeding-associated mortality are predicted to amplify the relative fitness benefits and hence enhance the strength of selection for behavioural alteration\u

Spliced DNA sequences in the Paramecium germline: their properties and evolutionary potential

Despite playing a crucial role in germline-soma differentiation, the evolutionary significance of developmentally regulated genome rearrangements (DRGRs) has received scant attention. An example of DRGR is DNA splicing, a process that removes segments of DNA interrupting genic and/or intergenic sequences. Perhaps, best known for shaping immune-system genes in vertebrates, DNA splicing plays a central role in the life of ciliated protozoa, where thousands of germline DNA segments are eliminated after sexual reproduction to regenerate a functional somatic genome. Here, we identify and chronicle the properties of 5,286 sequences that putatively undergo DNA splicing (i.e., internal eliminated sequences [IESs]) across the genomes of three closely related species of the ciliate Paramecium (P. tetraurelia, P. biaurelia, and P. sexaurelia). The study reveals that these putative IESs share several physical characteristics. Although our results are consistent with excision events being largely conserved between species, episodes of differential IES retention/excision occur, may have a recent origin, and frequently involve coding regions. Our findings indicate interconversion between somatic—often coding—DNA sequences and noncoding IESs, and provide insights into the role of DNA splicing in creating potentially functional genetic innovation

The influence of air-sea exchange on the isotopic composition of oceanic carbon: Observations and modeling

Although the carbon isotopic composition of ocean waters after they leave the surface ocean is determined by biological cycling, air-sea exchange affects the carbon isotopic composition of surface waters in two ways. The equilibrium fractionation between oceanic and atmospheric carbon increases with decreasing temperature. In Southern Ocean Surface Waters this isotopic equilibration enriches δ13C relative to the δ13C expected from uptake and release of carbon by biological processes alone. Similarly, surface waters in the subtropical gyres are depleted in δ13C due to extensive air-sea exchange at warm temperatures. Countering the tendency toward isotopic equilibration with the atmosphere (a relatively slow process), are the effects of the equilibration of CO2 itself (a much faster process). In regions where there is a net transfer of isotopically light CO2 from the ocean to the atmosphere (e.g., the equator) surface waters become enriched in 13C, whereas in regions where isotopically light CO2 is entering the ocean (e.g., the North Atlantic) surface waters become depleted in 13C. A compilation of high quality oceanic δ13C measurements along with experiments performed using a zonally averaged three-basin dynamic ocean model are used to explore these processes

High-frequency side-scan sonar fish reconnaissance by autonomous underwater vehicles

Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of NRC Research Press for personal use, not for redistribution. The definitive version was published in Canadian Journal of Fisheries and Aquatic Sciences 74 (2017): 240-255, doi:10.1139/cjfas-2015-0301.A dichotomy between depth penetration and resolution as a function of sonar frequency, draw resolution, and beam spread challenges fish target classification from sonar. Moving high-frequency sources to depth using autonomous underwater vehicles (AUVs) mitigates this and also co-locates transducers with other AUV-mounted short-range sensors to allow a holistic approach to ecological surveys. This widely available tool with a pedigree for bottom mapping is not commonly applied to fish reconnaissance and requires the development of an interpretation of pelagic reflective features, revisitation of count methods, image-processing rather than wave-form recognition for automation, and an understanding of bias. In a series of AUV mission test cases, side-scan sonar (600 and 900 kHz) returns often resolved individual school members, spacing, size, behavior, and (infrequently) species from anatomical features and could be intuitively classified by ecologists — but also produced artifacts. Fish often followed the AUV and thus were videographed, but in doing so removed themselves from the sonar aperture. AUV-supported high-frequency side-scan holds particular promise for survey of scarce, large species or for synergistic investigation of predators and their prey because the spatial scale of observations may be similar to those of predators.AUV missions were funded by an Office of Naval Research grant to the Woods Hole Oceanographic Institution and Rutgers University. The field work was supported by the Office of Naval Research under grant N00014-11-1-0160

The Role and Responsibility of Prosecutors

In this panel, the discussion moves form the abstract to the very specific. Moderator Thomas Metzloff, professor of law at Duke University School of Law, asks the panelists to analyze the actions leading to the disbarment of former Durham District Attorney Mike Nifong. The speakers, all current or former prosecutors, detail personal experiences dealing with reporters, and discuss the guidelines, written and unwritten, which govern such interaction. Questions/themes/discussion topics The press as a tool to communicate with the public The press as a watchdog Training of young prosecutors in press interaction The effect of the U.S. Supreme Court\u27s 2002 decision in Minnesota v. White on regulating attorney speech Strategic advantages (or lack thereof) to press interaction To what degree can prosecutors control leaks from their office or, more problematically, from the local police department? Public statements as jury pool pollutant