The optimal level of fuzz: case studies in a methodology for psychological research

Cognitive science research is hard to conduct, because researchers must take phenomena from the world and turn them into laboratory tasks for which a reasonable level of experimental control can be achieved. Consequently, research necessarily makes tradeoffs between internal validity (experimental control) and external validity (the degree to which a task represents behaviour outside of the lab). Researchers are thus seeking the best possible trade-off between these constraints, which we refer to as the optimal level of fuzz. We present two principles for finding the optimal level of fuzz, in research, and then illustrate these principles using research from motivation, individual differences and cognitive neuroscience.     

WAVELET-BASED STEGANOGRAPHY

Wavelets, which are used to separate data into different components, have many applications. Steganography, one such application, is a form of secret communication where the existence of a message is concealed. Methods for applying univariate and bivariate wavelets to steganography include embedding messages into the insignificant wavelet coefficients of decomposed signals and images. Recomposing then creates stego-objects that appear unaltered from the original cover-objects. First demonstrated is a technique for hiding messages in strings of data with linear trends using the univariate Daubechies D ₄ wavelets. Then, after developing the bivariate Haar wavelets and filters, a unique process of decomposing and recomposing an image in greyscale in order to implement steganography will be illustrated.     

Using digital cameras for river plume and water quality measurements

The results from a pilot study in coastal waters off the east coast of Ireland using both an in situ and airborne mounted digital camera are described. In situ digital pictures are significantly affected by sea surface reflection. This can be eliminated with the use of a hollow pipe, attached to the camera lens, which intersects the sea surface such that a picture of light upwelled from beneath the surface is obtained. Used in this way, linear relations between both the ratio of red/green digital output (O/P) values (at a particular camera exposure) and the difference in green–red digital camera O/P were found with mineral suspended solid (MSS) concentration. A good comparison was also found between the ratios of red/green upwelling light measured with the camera and a conventional irradiance sensor. Semi‐empirical or analytical relationships between camera O/P and the inherent optical properties of the water could not be established, however. This was probably due, in part, to a lack of range in values for the water constituent parameters. An airborne mounted digital camera was used to successfully monitor the dynamics of a river plume discharging into the coastal water. The high dissolved organic material (CDOM) levels within the plume caused the plume to be easily visible in the digital imagery, with a significantly increased signal in the camera's red/green O/P values marking the spatial extent of the plume. The plume dynamics were principally controlled by the tidal flows in the coastal waters. During the ebb tide strong fronts, and inferred convergence zones, marked the edge of the river plume and were associated with increased values of the camera‐derived red/green ratio. As slack water commenced, the plume expanded away from the source and became thinner, with a decreased red/green signal. Associated with this time internal fronts were present within the plume's extent, marked by step changes, or spikes, in the camera's red/green values.     

The discrepancy-attribution hypothesis: II. Expectation, uncertainty, surprise, and feelings of familiarity.

In the accompanying article (B. W. A. Whittlesea and L. D. Williams, see record 2000-14052-001), surprising violation of and expectation was observed to cause an illusion of familiarity. The authors interpreted that evidence as support for the discrepancy-attribution hypothesis. This article extended the scope of that hypothesis, investigating the consequences of surprising validation of expectations. Ss were shown recognition probes as completions of sentence stems. Their expectations were manipulated by presenting predictive, nonpredictive, and inconsistent stems. Predictive stems caused an illusion of familiarity, but only when the Ss also experienced uncertainty about the outcome. That is, as predicted by the discrepancy-attribution hypothesis, feelings of familiarity occurred only when processing of a recognition target caused surprise. The article provides a discussion of the ways in which a perception of discrepancy can come about, as well as the origin and nature of unconscious expectation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrierte Wertschöpfungsnetzwerke – Chancen und Potenziale durch Industrie 4.0

The Smart Factory is the central element of Industry 4.0 and establishes the foundation to enable integrated value chains across companies. The linkage of information along value chains offers a wide range of opportunities and potentials to realize new innovative solutions.     

Biochemical Functions of Geophagy in Parrots: Detoxification of Dietary Toxins and Cytoprotective Effects

This study tests hypotheses on the biochemical functions of geophagy in parrots: mechanical enhancement of digestion, acid buffering capacity, mineral supplementation, adsorption of dietary toxins, and gastrointestinal cytoprotection. Parrots showed clear preferences for specific soil horizons. Comparisons of preferred and nonpreferred soils from several sites suggest that soils have little ability to enhance grinding and no measurable ability to buffer gastric pH. Soils offered insignificant mineral supplementation since most minerals occurred at similar levels in samples regardless of preference, and the minerals were generally more plentiful in the birds' diets. Sodium was available in moderate levels at some sites (>1000 ppm), but was well below sodium detection thresholds of parrots. X-ray diffraction, cation exchange capacity, and in vitro adsorptive trials showed that the preferred soils are capable of exchanging substantial quantities of cations and are capable of adsorbing low-molecular-weight secondary compounds. In captive Amazona parrots, orally administered clay reduced the bioavailability of the alkaloid quinidine by roughly 60%, demonstrating that in vivo adsorption of potentially toxic compounds may be a biologically important function of geophagy. Labeled clay remained in the lower gastrointestinal tract of captive parrots for >12 hr, which along with high adsorptive capacities, further suggests a potential role in protecting the gastrointestinal lining from various biological and chemical insults. Detoxification and cytoprotection are the most likely functions of geophagy for parrots and herbivores with similar ecologies. Given the variety of chemically defended seeds consumed by these herbivores, geophagy likely protects consumers from dietary toxins, allowing increased diet breadth and/or enhancing digestibility.     

Automated Separation and Conductimetric Determination of Inorganic Nitrogen

Experiments were conducted for the evaluation of a continuous flow conductimetric method that measures the inorganic nitrogen compounds ammonia (NH3) and combined nitrite (NO2?) and nitrate (NO3?). Approximately 300 analyses were performed using the method during experiments to estimate the method detection level, to determine the bias and precision, and to determine the equivalency of the method to others found in Standard Methods. An estimated method detection level of 0.01 mg N∕L (NH3–N, NO3?–N, or NO2?–N) was measured. Precision values for ammonia and nitrate standards at concentrations ranging from 0.1 to 75 mg∕L NH3–N or NO3?–N did not exceed 5.5 and 4%, respectively. Recovery values for ammonia and nitrate standards at the same concentration range did not exceed 104.8 and 103%, respectively. At concentrations of 0.05 mg∕L NH3–N or NO3?–N, the precision values were 12.5 and 11%, respectively, which were high relative to others obtained in this study but are within the range of values reported in Standard Methods.