Errors in the heat of battle: taking a closer look at shared cognition breakdowns through teamwork

OBJECTIVE: We developed a theoretically based taxonomy for classifying shared cognition breakdowns related to teamwork which contribute to fratricide incidents. BACKGROUND: Fratricide on the battlefield is an inescapable cost of war. A number of technological advancements have been made in terms of combat identification systems to reduce the risk of these incidents. However, fratricide continues to occur at alarming rates. METHOD: We take a human-centered approach to understanding errors leading to fratricide incidents by focusing on shared cognition. We turn to the literature and provide the theoretical foundations for an error classification taxonomy to improve understanding of why fratricide incidents occur. RESULTS: Based on our review of the literature, we identified a number of problem areas leading to fratricide incidents. However, many of the cited contributing factors were broad terms (e.g., poor coordination) and did little to tell us why the breakdown occurred and where improvements are needed. Therefore, we chose to focus on one specific area--teamwork breakdowns--and discuss in depth how these breakdowns contribute to fratricide. CONCLUSION: In this paper, we take a first step toward proposing a taxonomy that allows for the diagnostic assessment of what causes teamwork breakdowns in fratricide. We understand that a taxonomy is only as good as the data available and encourage richer case studies from which to learn. APPLICATION: To apply this taxonomy in an operational setting, we provide a set of behavioral markers that can be used to identify teamwork breakdowns on the battlefield.     

A statistics-based approach to binary image registration with uncertainty analysis

A new technique is described for the registration of edge-detected images. While an extensive literature exists on the problem of image registration, few of the current approaches include a well-defined measure of the statistical confidence associated with the solution. Such a measure is essential for many autonomous applications, where registration solutions that are dubious (involving poorly focused images or terrain that is obscured by clouds) must be distinguished from those that are reliable (based on clear images of highly structured scenes). The technique developed herein utilizes straightforward edge pixel matching to determine the "best" among a class of candidate translations. A well-established statistical procedure, the McNemar test, is then applied to identify which other candidate solutions are not significantly worse than the best solution. This allows for the construction of confidence regions in the space of the registration parameters. The approach is validated through a simulation study and examples are provided of its application in numerous challenging scenarios. While the algorithm is limited to solving for two-dimensional translations, its use in validating solutions to higher-order (rigid body, affine) transformation problems is demonstrated     

The Growth‐Inhibiting Effects of Beef Fatty Acids on MCF‐7 Cells Are Influenced Mostly by the Depot Location and Inconsistently by the Biohydrogenation Intermediate Content

Biohydrogenation intermediates (BHI) including conjugated linoleic acid (CLA) isomers are formed during ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) in ruminants. Although many studies have examined the anticarcinogenic effects of CLA, few studies have reported the anticarcinogenic properties of BHI in their natural form found in dairy and beef fats. The present study compared the growth‐inhibitory effects of fatty acids from beef perirenal fat (PRF) or subcutaneous fat (SCF) with low or high levels of BHI in MCF‐7 human breast cancer cells. Cells were exposed for 72 h to media containing increasing doses (50 to 400 μM) of different beef fat treatments. Fatty‐acid analysis showed that BHI were readily incorporated into cell phospholipids (PL) in a treatment‐dependent manner, but higher BHI in PL did not consistently inhibit growth. Culturing with low‐BHI PRF or high‐BHI PRF did not lead to growth inhibition, but low‐BHI SCF inhibited growth, and inhibition was further increased by high‐BHI SCF. Other classes of fatty acids may, therefore, be interacting with BHI resulting in differential effects on growth inhibition in human breast cancer cells.     

Peroxidation reactions in plant membranes: Effects of free fatty acids

Free fatty acids accumulate in plant membranes after exposure of plants to environmental stress, such as freezing and desiccation. Fatty acid accumulation has been linked to various biophysical changes and to the occurrence of lipid peroxidation, but the relationships appear complex and inconsistent. The interactions between oxygen free radicals, free fatty acids and lipid peroxidation in plant membranes were examined further by studying peroxidation reactions in a model membrane system composed of a complex mixture of plant phospholipids, including various free fatty acids. Multilamellar liposomes were treated with oxygen free radicals generated from iron ascorbate. Increased concentrations of free palmitic acid up to 10 mol% (fatty acid/phospholipid) reduced the production of aldehydes detected by the thiobarbituric acid assay, but enhanced the production of fluorescent products. By contrast, increased concentrations of free linolenic acid increased aldehyde production and reduced the formation of fluorescent products. The two free fatty acids both enhanced the susceptibility of phospholipids to degradation as shown by the reduced recovery of esterified polyunsaturated fatty acids (linoleic and linolenic). The free radical reactions with or without free fatty acid additions catalyzed the selective degradation of phospholipids in the order phosphatidylethanolamine > phosphatidylcholine > phosphatidylinositol > phosphatidylglycerol. Selective degradation of phospholipids is often observed after periods of environmental stress or during senescence of plants, and has been cited as evidence for the involvement of phospholipases in these degenerative processes. The results indicate that selectivity is not a criterion for eliminating the involvement of oxygen free radicals in these degenerative processes. Furthermore, the results suggest that modifications of lipid composition during a plant's acclimation to adverse environments may determine the types of free radical reactions that occur due to stress.     

Iterative design of a semi-autonomous social telepresence robot research platform: a chronology

Our research focuses on how a telepresence robot operator, the people with the robot, and the robot itself collaborate so that the operator reaches his/her intended destination. Our research requires higher levels of autonomous navigation so that the robot can, for example, go to a specified destination and follow a person. However, commercial telepresence robots are primarily teleoperated, and only a few provide assisted navigation around obstacles. Our system must include sensors and processing to enable these capabilities. We present the chronology of our iterative design for augmenting two VGo Communications’ VGo robots, Hugo and Margo, over a period of 3 years. We detail the requirements and design constraints encountered while developing our telepresence robot platforms.     

Effect of acylation stimulating protein on the triacylglycerol synthetic pathway of human adipose tissue

Acylation stimulating protein (ASP) is a 14 kDa plasma protein which causesin vitro triacylglycerol synthesis in human adipocytes and fibroblasts to increase substantially. ASP was found to stimulate human adipose tissue microsomal glycerophosphate acyltransferase and diacylglycerol acyltransferase activities by 23% and 90%, respectively. However, phosphatidate phosphohydrolase activity showed no increase in activity, nor did microsomal acyl-CoA synthetase activity. Moreover, ASP did not decrease the apparent K_m of diacylglycerol acyltransferase (DGAT), but rather increased its apparent V_max suggesting direct interaction of ASP with DGAT.     

Study of the incorporation of protic ionic liquids into hydrophilic and hydrophobic rigid-rod elastomeric polymers

A series of polymers was synthesized that contain a rigid aromatic backbone connected through triazine linkages that are cross-linked by flexible diamine-terminated poly(ethylene oxide) oligomers. Polymers were made that contained both hydrophilic sulfonated aromatic and hydrophobic pyridinium triflate backbones. Thermal and mechanical properties of the resulting polymer films were studied, as well as uptake of water and protic ionic liquids. Ionic liquid uptake varied from 41 to 440%, depending upon the nature of the polymer. The ionic liquid-doped films were analyzed for proton conductivity at high temperatures (>150 °C) under non-humidified conditions. Conductivities as high as 5×10⁻² S/cm were observed at 150 °C.     

Cyclization dynamics of polymers: 10 Synthesis,fractionation, and fluorescent spectroscopy of pyrene end-capped polystyrenes

The rate constant for end-to-end cyclization (k₁) for polymer chains is predicted to decrease sensitively with increasing chain length. In this paper the techniques are examined critically for extracting values of k₁ from experiments involving intramolecular pyrene excimer formation in polymers of the form pyrene-polystyrene-pyrene. For significance, results require samples of appropriately narrow molecular weight distribution ($\text{M}\text{?}{}_{\mathrm{w}}\text{M}\text{?}{}_{\mathrm{n}}\text{</ 1.13}$), as well as corrections for polydispersity differences among the samples. Particular attention is focussed both on experimental techniques and on the models used to interpret the kinetics of intramolecular pyrene excimer formation.     

Gelatinized starch/biodegradable polyester blends: Processing,morphology, and properties

Blends of polycaprolactone (PCL)/gelatinized starch and polybutylene succinate adipate/gelatinized starch have been prepared in various ratios and their phase morphology and thermal/mechanical properties have been analyzed. For both the PCL/plasticized starch and polybutylene succinate adipate/plasticized starch blends the resistance to impact increased with increasing polyester content, and the tensile modulus reached a maximum at around 80 wt % polyester content. In blends containing up to 70 wt % polyester (as observed by scanning electron microscopy) a hierarchical dispersion of the gelatinized starch phase was observed (distinct domain sizes of those less than 5 μm and those greater than 15 μm) and in the blends containing 70–90 wt % polyester a more singular dispersed phase of gelatinized starch was observed within the polyester matrix. Dynamical mechanical analysis results showed some phase mixing was present in the PCL/gelatinized starch blends noted by the appearance of an additional tan δ peak located between the glass transition temperatures of the respective components and broadening of the low temperature transition corresponding to the T_g of the polyester (possibly the result of a starch‐rich polyester phase) with some overlap with the low temperature β transition of the gelatinized starch itself. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 802–811, 2007     

Variability of chemosensory stimuli within honeybee (Apis mellifera) colonies: Differential conditioning assay for discrimination cues

Differential training of honeybee workers using the proboscis extension reflex is applied to the problem of evaluating compounds that may potentially provide cues for kin recognition in the honeybeeApis mellifera. These cues were obtained by contaminating glass rods and steel needles with different materials found in the hive. In particular it is shown that workers discriminate between: cuticular waxes from different adult workers; eggs from the same and different hives; similar aged larvae within the same hive; and needles contaminated with the Nasonov gland secretions of different adult workers. It appears that some of these differences are due to phenotypic variation among individuals that cannot be directly attributed to environmental factors.