Can auditory objects be subitized?

In vision, humans have the ability to mentally 'tag' approximately four objects, allowing us to monitor, attend, and interact with them. As a consequence, we can rapidly and accurately enumerate up to four objects – a process known as subitizing. Here, we investigate whether a similar ability exists for tagging auditory stimuli and find that only two or three auditory stimuli can be enumerated with high accuracy. We assess whether this high accuracy indicates the existence of an auditory subitizing mechanism, and if it is influenced by factors known to influence visual subitizing. Based on accuracy, Experiments 1 and 2 reveal a potential auditory subitizing mechanism only when stimuli are spatially separated, as is the case for visual subitizing. Experiment 3 failed to show any evidence of auditory subitizing when objects were separated in time, rather than space. All three experiments provide only limited evidence for an age-related decline in auditory enumeration of small numbers of objects. This suggests that poor auditory tagging does not contribute significantly to older adults’ difficulties in multi-talker conversations. We hypothesize that although auditory subitizing might occur, it is restricted to approximately two spatially-separated objects due to the difficulty of parsing the auditory scene into its constituent parts

How to extend Roberts' Law for eccentrically driven, inverted slider-cranks

The extension of Roberts' Law concerns inverted slider-cranks with an eccentricity and a general tracing-point attached to the moving plane of the slider. As both curve-cognates degenerate in this case, the infinite turning-joint has first been replaced by a finite far-away joint, but such that the coupler-plane also meets two accuracy-positions of the erstwhile slider. One of the curve-cognates may then be adapted or modified until up to six accuracy positions are met. They seem to be sufficient to attain an extraordinary good approximation of the entire branch of the original curve. Besides, even the transmission-angle attains a value about twice as large as the one obtained with the auxiliary four-bar representing the first approximation. Cases, where the inverted slider-crank turns into a crank-and-rocker, into a double crank or even into a stretchable four-bar, are shown. The latter corresponds with one of Grashofs border cases for the inverted slider-crank. Roberts' Law then ensures that each inverted slider-crank, having a fully revolving crank, possesses three four-bar branchcognates this way

Effluent Organic Nitrogen (EON): Bioavailability and Photochemical and Salinity-Mediated Release

The goal of this study was to investigate three potential ways that the soluble organic nitrogen (N) fraction of wastewater treatment plant (WWTP) effluents, termed effluent organic N (EON), could contribute to coastal eutrophication - direct biological removal, photochemical release of labile compounds, and salinity-mediated release of ammonium (NH4+). Effluents from two WWTPs were used in the experiments. For the bioassays, EON was added to water from four salinities (similar to 0 to 30) collected from the James River (VA) in August 2008, and then concentrations of N and phosphorus compounds were measured periodically over 48 h. Bioassay results, based on changes in DON concentrations, indicate that some fraction of the EON was removed and that the degree of EON removal varied between effluents and with salinity. Further, we caution that bioassay results should be interpreted within a broad context of detailed information on chemical characterization. EON from both WWTPs was also photoreactive, with labile NH4+ and dissolved primary amines released during exposure to sunlight. We also present the first data that demonstrate that when EON is exposed to higher salinities, increasing amounts of NH4+ are released, further facilitating EON use as effluent transits from freshwater through estuaries to the coast

Library subject guides: A case study of evidence-informed library development

This paper describes the process whereby a university library investigated the value of its subject guides to its users. A literature review and surveys of library staff, library users and other libraries were carried out. Existing library subject guides and those of other higher education libraries were evaluated. The project team reported regularly to the wider library team throughout the year long investigation and made recommendations. The project served to develop the professional skills of the project team, to expand the knowledge of the wider library team and encouraged new ways of thinking about guide provision to users

Willingness to Pay for Genetic Testing for Alzheimer's Disease: A Measure of Personal Utility

Background: The increased availability of genetic tests for common, complex diseases, such as Alzheimer's disease (AD), raises questions about what people are willing to pay for these services. Methods: We studied willingness-to-pay for genetic testing in a study of AD risk assessment that included APOE genotype disclosure among 276 first-degree relatives of persons with AD. Results: Seventy-one percent reported that they would ask for such testing from their doctor if it were covered by health insurance, and 60% would ask for it even if it required self-pay. Forty-one percent were willing to pay more than $100 for testing, and more than half would have been willing to pay for the test out of pocket. Participants who learned that they were APOE -4 positive and those who had higher education were less likely to want testing if covered by insurance, possibly to avoid discrimination. Conclusion: This is the first report to examine willingness to pay for susceptibility genetic testing in a sample of participants who had actually undergone such testing. These findings reveal that some participants find valuable personal utility in genetic risk information even when such information does not have proven clinical utility.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90504/1/gtmb-2E2011-2E0028.pd

Atom--Molecule Coherence in a Bose-Einstein Condensate

Coherent coupling between atoms and molecules in a Bose-Einstein condensate (BEC) has been observed. Oscillations between atomic and molecular states were excited by sudden changes in the magnetic field near a Feshbach resonance and persisted for many periods of the oscillation. The oscillation frequency was measured over a large range of magnetic fields and is in excellent quantitative agreement with the energy difference between the colliding atom threshold energy and the energy of the bound molecular state. This agreement indicates that we have created a quantum superposition of atoms and diatomic molecules, which are chemically different species.Comment: 7 pages, 6 figure

Imaging the human hippocampus with optically-pumped magnetoencephalography

Optically-pumped (OP) magnetometers allow magnetoencephalography (MEG) to be performed while a participant’s head is unconstrained. To fully leverage this new technology, and in particular its capacity for mobility, the activity of deep brain structures which facilitate explorative behaviours such as navigation, must be detectable using OP-MEG. One such crucial brain region is the hippocampus. Here we had three healthy adult participants perform a hippocampal-dependent task – the imagination of novel scene imagery – while being scanned using OPMEG. A conjunction analysis across these three participants revealed a significant change in theta power in the medial temporal lobe. The peak of this activated cluster was located in the anterior hippocampus. We repeated the experiment with the same participants in a conventional SQUID-MEG scanner and found similar engagement of the medial temporal lobe, also with a peak in the anterior hippocampus. These OP-MEG findings indicate exciting new opportunities for investigating the neural correlates of a range of crucial cognitive functions in naturalistic contexts including spatial navigation, episodic memory and social interactions

Mathematical and computational models of the retina in health, development and disease

The retina confers upon us the gift of vision, enabling us to perceive the world in a manner unparalleled by any other tissue. Experimental and clinical studies have provided great insight into the physiology and biochemistry of the retina; however, there are questions which cannot be answered using these methods alone. Mathematical and computational techniques can provide complementary insight into this inherently complex and nonlinear system. They allow us to characterise and predict the behaviour of the retina, as well as to test hypotheses which are experimentally intractable. In this review, we survey some of the key theoretical models of the retina in the healthy, developmental and diseased states. The main insights derived from each of these modelling studies are highlighted, as are model predictions which have yet to be tested, and data which need to be gathered to inform future modelling work. Possible directions for future research are also discussed. Whilst the present modelling studies have achieved great success in unravelling the workings of the retina, they have yet to achieve their full potential. For this to happen, greater involvement with the modelling community is required, and stronger collaborations forged between experimentalists, clinicians and theoreticians. It is hoped that, in addition to bringing the fruits of current modelling studies to the attention of the ophthalmological community, this review will encourage many such future collaborations

Reproducibility of four frequently used local heating protocols to assess cutaneous microvascular function.

BACKGROUND: Skin microvascular responses to local heating are frequently used to assess microvascular function. Several local heating protocols have been developed, all varying slightly in execution. The aim of this study was to determine the inter-day reproducibility of the four most commonly used local heating protocols in healthy young subjects. METHODS: Fifteen, healthy males (28±5yrs, BMI 25±2kg/m(2)) attended two experimental trials 2-7days apart. During each trial, baseline and maximal thermally stimulated forearm skin responses were examined simultaneously at four sites on the dominant forearm using laser Doppler flowmetry (LDF). The following heating protocols were adopted: 1. Rapid 39°C (0.5°C/5s), 2. Rapid 42°C (0.5°C/5s) 3. Gradual 42°C (0.5°C/2min 30s) and 4. Slow 42°C (0.5°C/5min). The coefficient of variation (CV) was calculated for absolute flux, cutaneous vascular conductance (CVC; flux/mean arterial pressure, MAP) and CVC expressed as a percentage of maximal CVC at 44°C (%CVCmax) at three different time points; baseline (33°C), plateau (39/42°C) and maximal (44°C). RESULTS: Reproducibility of baseline flux, CVC and %CVCmax was 17-29% across all protocols. During the plateau, Rapid, Gradual and Slow 42°C demonstrated a reproducibility of 13-18% for flux and CVC and 5-11% for %CVCmax. However, Rapid 39°C demonstrated a lower reproducibility for flux, CVC and %CVCmax (all 21%). Reproducibility at 44°C was 12-15% for flux and CVC across all protocols. CONCLUSION: This is the first study examining inter-day reproducibility across four local heating protocols. The good-to-moderate reproducibility of the Rapid, Gradual and Slow 42°C protocols support their (simultaneous) use to assess microvascular function. Using Rapid 39°C may require a greater number of subjects to detect differences within subjects