Selective low concentration ammonia sensing in a microfluidic lab-on-a-chip

In the medical community, there is a considerable interest in a diagnostic breath analyzer for ammonia that is selectively enough to measure in exhaled air and small enough for the small volumes available in such an application. An indirect measurement system for low gaseous ammonia concentrations has been miniaturized and integrated on a chip in order to reach this goal. The detection limit of the system was calculated to be 1.1 parts per billion (ppb). The response time was determined to be 1.6 min with a gas How of 50 ml/min. The required gas volume for one measurement is therefore sufficiently small, although sampling assistance is required for breath analysis. The selectivity of the system is sufficient to measure ammonia concentrations in the low-ppb range. The system is even sufficiently selective to be used in environments that contain elevated carbon dioxide levels, like exhaled air. The lower ammonia concentration expected in diagnostic breath analysis applications, 50 ppb, was demonstrated to be detectable

Flash suppression and flash facilitation in binocular rivalry

We show that previewing one half image of a binocular rivalry pair can cause it to gain initial dominance when the other half is added, a novel phenomenon we term flash facilitation. This is the converse of a known effect called flash suppression, where the previewed image becomes suppressed upon rivalrous presentation. The exact effect of previewing an image depends on both the duration and the contrast of the prior stimulus. Brief, low-contrast prior stimuli facilitate, whereas long, high-contrast ones suppress. These effects have both an eye-based component and a pattern-based component. Our results suggest that, instead of reflecting two unrelated mechanisms, both facilitation and suppression are manifestations of a single process that occurs progressively during presentation of the prior stimulus. The distinction between the two phenomena would then lie in the extent to which the process has developed during prior stimulation. This view is consistent with a neural model previously proposed to account for perceptual stabilization of ambiguous stimuli, suggesting a relation between perceptual stabilization and the present phenomena

In depth compositional analysis of ceramic (Bi2O3)0.75(Er2O3)0.25 by AES and XPS

The chemical composition of dense ceramics of erbia-stabilized δ-Bi2O3 was analyzed by Auger electron spectroscopy (AES) depth profiling using Ar+ ion sputtering. The relative sensitivity factors (rsf) and sputter rates of bismuth and erbium in this material have been determined by electron probe microanalysis (EPMA) and chemical analysis. These results, supplemented by data from angle resolved X-ray photoelectron spectroscopy (ARXPS), shows a bismuth enrichment at the surface. Evidence has been found for reduction of the bismuth-oxide at the outermost part of the surface layer

A putative serine protease, SpSsp1, from Saprolegnia parasitica is recognised by sera of rainbow trout, Oncorhynchus mykiss

Acknowledgements Our work was supported by the BBSRC (BB/C518457/1, BB/G012075/1, BB/J018333/1) (K.L.M., C.J.S., J.S.C., K.S.D., and P.v.W.), the University of Aberdeen (V.L.A., C.J.S., and P.v.W.), MSD Animal Health (J.S.C., K.S.D., and A.H.v.d.B), and The Royal Society (P.v.W.). This work was also supported by a Marie Curie Initial Training Networks with the SAPRO (sustainable approaches to reduce Oomycete (Saprolegnia) infections in aquacultures) grant PITN-GA-2009-238550 (A.H.v.d.B., L.L., C.J.S., P.v.W.). We would like to acknowledge Aberdeen Proteomics for carrying out LC–MS/MS and Laura Grenville-Briggs for valuable discussion and technical help. We are grateful to the Broad Institute (Carsten Russ, Rays Jiang, Brian Haas, and Chad Nusbaum), Brett Tyler (VBI), and P.v.W. for early release of draft supercontigs of the genome sequence of isolate CBS233.65, which helped us identify SpSsp1.Peer reviewedPublisher PD

Extensive Modeling of a Coaxial Stub Resonator for Online Fingerprinting of Fluids

A straightforward method of extensive modeling of a lossy stub resonator system for online fingerprinting of fluids is presented in this paper. The proposed model solves the telegrapher's equations including the skin effect and dielectric losses and describes the amplitude versus frequency response of lossy coaxial stub resonators with a fluid under investigation as dielectric. The adequacy of the method is demonstrated by comparing simulations with experimentally obtained data. Even though we applied the model to a coaxial stub resonator for the online fingerprinting of fluids (e.g., for water quality monitoring), the potential applicability of the method reaches further. Indeed, the method introduced here may be useful for different types of sensors based on lossy transmission line theor

Erratum: Micromachined Fabry-Pérot Interferometer with Embedded Nanochannels for Nanoscale Fluid Dynamics

In ref 1, the erroneous numbers are not discussed in detail, yet we briefly noted, p 349, the observation of an enhanced ﬿lling speed with respect to the Lucas Washburn equation...

Micromachined Fabry-Perot interferometer with embedded nanochannels for nanoscale fluid dynamics

We describe a microfabricated Fabry-Pérot interferometer with nanochannels of various heights between 6 and 20 nm embedded in its cavity. By multiple beam interferometry, the device enables the study of liquid behavior in the nanochannels without using fluorescent substances. During filling studies of ethanol and water, an intriguing filling mode for partially wetting water was observed, tentatively attributed to the entrapment of a large amount of gas inside the channels

The Nature and Conceptualisation of Career Transitions in Sport

First paragraph: While an athlete’s sports career may seem to develop in a smooth and continuous way from beginning to end, it is in fact characterized by specific phases and transitions. Asked to describe its development, athletes highlight their athletic career, for example, in terms of specific moments or situations which occurred throughout their career (Wylleman & De Knop, 1997a,b). These moments or situations do not only require athletes to cope with specific changes, but are also perceived by the athletes to influence the quality of their participation at their current competitive level. The occurrence of phases and transitions in the athletic career can also be illustrated by chronologically pin-pointing athletes’ sport achievements (e.g., a first national championship title) and selections (e.g., selection for the national team). Comparison of such developmental data has revealed many similarities in (elite) athletes’ athletic careers (Stambulova, 1998; Wylleman & De Knop, 1998): athletes start out in their sport at the ages of approximately 8 to 12 years-of-age; one or two years later athletes start competing at club level, and go, some three to four years later on to national level; a first selection for a national team occurs somewhere between 17-19 years-of-age, while a first Olympic selection is achieved during their early twenties; and finally, athletes do end their involvement in highlevel competitive sport at approximately 30 years-of-age (3). In fact, researchers have been able to identify a sequence of career developmental phases, not only with elite level athletes, but with talented performers in general, namely an initiation, a development, a mastery, and a post-career phase (e.g., Bloom, 1985; Salmela; 1994)

Corrigendum: Normal Values of Corrected Heart-Rate Variability in 10-Second Electrocardiograms for All Ages

Cardiolog