LANDSAT follow-on experiment: Gulf of Mexico menhaden and thread herring resources investigation

The author has identified the following significant results. The most significant achievement realized is the successful mapping of high probability fishing areas from LANDSAT MSS data for two Mississippi Sound missions

Relationships between remotely sensed fisheries distribution information and selected oceanographic parameters in the Mississippi Sound

A feasibility study to demonstrate the potential of satellites for providing fisheries significant information was conducted in the Mississippi Sound and adjacent offshore waters. Attempts were made to relate satellite acquired imagery to selected oceanographic parameters and then to relate these parameters to aircraft remotely sensed distribution patterns of resident surface schooling fishes. Initial results suggest that this approach is valid and that the satellite acquired imagery may have important fisheries resource assessment implications

Left parietal tACS at alpha frequency induces a shift of visuospatial attention

Background Voluntary shifts of visuospatial attention are associated with a lateralization of parieto-occipital alpha power (7-13Hz), i.e. higher power in the hemisphere ipsilateral and lower power contralateral to the locus of attention. Recent noninvasive neuromodulation studies demonstrated that alpha power can be experimentally increased using transcranial alternating current stimulation (tACS). Objective/Hypothesis We hypothesized that tACS at alpha frequency over the left parietal cortex induces shifts of attention to the left hemifield. However, spatial attention shifts not only occur voluntarily (endogenous/ top-down), but also stimulus-driven (exogenous/ bottom-up). To study the task-specificity of the potential effects of tACS on attentional processes, we administered three conceptually different spatial attention tasks. Methods 36 healthy volunteers were recruited from an academic environment. In two separate sessions, we applied either high-density tACS at 10Hz, or sham tACS, for 35–40 minutes to their left parietal cortex. We systematically compared performance on endogenous attention, exogenous attention, and stimulus detection tasks. Results In the endogenous attention task, a greater leftward bias in reaction times was induced during left parietal 10Hz tACS as compared to sham. There were no stimulation effects in either the exogenous attention or the stimulus detection task. Conclusion The study demonstrates that high-density tACS at 10Hz can be used to modulate visuospatial attention performance. The tACS effect is task-specific, indicating that not all forms of attention are equally susceptible to the stimulation

LANDSAT menhaden and thread herring resources investigation

The author has identified the following significant results. The most significant achievement is the successful charting of high probability fishing areas from LANDSAT MSS data

LANDSAT menhaden and thread herring resources investigation, Gulf of Mexico

The author has identified the following significant results. The most significant achievements thus far include the successful charting of high probability fishing areas from LANDSAT MSS data and the successful simulation of an operational satellite system to provide tactical information for the commercial harvest of menhaden

The Neural Basis of Conceptualizing the Same Action at Different Levels of Abstraction

People can conceptualize the same action (e.g., "riding a bike") at different levels of abstraction (LOA), where higher LOAs specify the abstract motives that explain why the action is performed (e.g., "getting exercise"), while lower LOAs specify the concrete steps that indicate how the action is performed (e.g., "gripping handlebars"). Prior neuroimaging studies have shown that why and how questions about actions differentially activate two cortical networks associated with mental-state reasoning and action representation, respectively; however, it remains unknown whether this is due to the differential demands of the questions per se or to the shifts in LOA those questions produce. We conducted functional MRI while participants judged pairs of action phrases that varied in LOA and that could be framed either as a why question (Why ride a bike? Get exercise.) or a how question (How to get exercise? Ride a bike.). Question framing (why vs. how) had no effect on activity in regions of the two networks. Instead, these regions uniquely tracked parametric variation in LOA, both across and within trials. This suggests that the human capacity to understand actions at different levels of abstraction is based in the relative activity of two cortical networks

Scattering by single physically large and weak scatterers in the beam of a single-element transducer

Quantitative ultrasound techniques are generally applied to characterize media whose scattering sites are considered to be small compared to a wavelength. In this study, the backscattered response of single weakly scattering spheres and cylinders with diameters comparable to the beam width of a 2.25 MHz single-element transducer were simulated and measured in the transducer focal plane to investigate the impact of physically large scatterers. The responses from large single spherical scatterers at the focus were found to closely match the plane-wave response. The responses from large cylindrical scatterers at the focus were found to differ from the plane-wave response by a factor of f(−1). Normalized spectra from simulations and measurements were in close agreement: the fall-off of the responses as a function of lateral position agreed to within 2 dB for spherical scatterers and to within 3.5 dB for cylindrical scatterers. In both measurement and simulation, single scatterer diameter estimates were biased by less than 3% for a more highly focused transducer compared to estimates for a more weakly focused transducer. The results suggest that quantitative ultrasound techniques may produce physically meaningful size estimates for media whose response is dominated by scatterers comparable in size to the transducer beam

Use of Spatial Communication in Aphasia

Background: Spatial communication consists of both verbal spatial language and gesture. There has been minimal research investigating the use of spatial communication, and even less focussing on people with aphasia. Aims: The aims of this exploratory study were to describe the frequency and variability of spatial language and gesture use by three participants with aphasia in comparison to nine control participants. This included: 1) frequency of gestures; 2) types of gesture; 3) number of spatial descriptions described by gestures but no language; and 4) frequency and variety of locative prepositional, verb, and noun phrases. Methods & Procedures: Each participant was videoed undertaking 11 spatial communication tasks: four description tasks, and seven tasks involving directing the researcher in the placement of objects or pictures. Gestures and language produced were transcribed and analysed. Outcomes & Results: Participants with aphasia used significantly more gesture. Participants with aphasia also used more gesture without spoken phrases when spatial vocabulary was unavailable. Finally, there were differences between the participants with regards to the types of gesture that they used when they were unable to access language. Conclusion & Implications: The results suggest that the analysis of gesture produced by people with aphasia may provide insight into their underlying language impairment. As this was an exploratory study, with just three participants with aphasia, further research is needed

LANDSAT menhaden and thread herring resources investigation

The author has identified the following significant results. The relationship between the distribution of menhaden and selected oceanographic parameters (water color, turbidity, and possibly chlorophyll concentrations) was established. Similar relationships for thread herring were not established nor were relationships relating to the abundance of either species. Use of aircraft and LANDSAT remote sensing instruments to measure or infer a set of basic oceanographic parameters was evaluated. Parameters which could be accurately inferred included surface water temperature, salinity, and color. Water turbidity (Secchi disk) was evaluated as marginally inferrable from the LANDSAT MSS data and chlorophyll-a concentrations as less than marginal. These evaluations considered the parameters only as experienced in the two test areas using available sensors and statistical techniques

A formal methodology for integral security design and verification of network protocols

We propose a methodology for verifying security properties of network protocols at design level. It can be separated in two main parts: context and requirements analysis and informal verification; and formal representation and procedural verification. It is an iterative process where the early steps are simpler than the last ones. Therefore, the effort required for detecting flaws is proportional to the complexity of the associated attack. Thus, we avoid wasting valuable resources for simple flaws that can be detected early in the verification process. In order to illustrate the advantages provided by our methodology, we also analyze three real protocols