Cholangitis Due to Candidiasis of the Extra-Hepatic Biliary Tract

A case of isolated candidal fungal balls in the common bile duct causing obstructive jaundice and cholangitis is described. There were no predisposing factors. The fungal balls were removed from the common bile duct and a transduodenal sphincteroplasty was performed. Microscopic analysis yielded colonies of candida. Postoperative period was uneventful. At follow-up no evidence of candida infection was evident. He is now 3 years post-surgery and is well

A statistical approach to finding overlooked genetic associations

<p>Abstract</p> <p>Background</p> <p>Complexity and noise in expression quantitative trait loci (eQTL) studies make it difficult to distinguish potential regulatory relationships among the many interactions. The predominant method of identifying eQTLs finds associations that are significant at a genome-wide level. The vast number of statistical tests carried out on these data make false negatives very likely. Corrections for multiple testing error render genome-wide eQTL techniques unable to detect modest regulatory effects.</p> <p>We propose an alternative method to identify eQTLs that builds on traditional approaches. In contrast to genome-wide techniques, our method determines the significance of an association between an expression trait and a locus with respect to the set of all associations to the expression trait. The use of this specific information facilitates identification of expression traits that have an expression profile that is characterized by a single exceptional association to a locus.</p> <p>Our approach identifies expression traits that have exceptional associations regardless of the genome-wide significance of those associations. This property facilitates the identification of possible false negatives for genome-wide significance. Further, our approach has the property of prioritizing expression traits that are affected by few strong associations. Expression traits identified by this method may warrant additional study because their expression level may be affected by targeting genes near a single locus.</p> <p>Results</p> <p>We demonstrate our method by identifying eQTL hotspots in <it>Plasmodium falciparum </it>(malaria) and <it>Saccharomyces cerevisiae </it>(yeast). We demonstrate the prioritization of traits with few strong genetic effects through Gene Ontology (GO) analysis of Yeast. Our results are strongly consistent with results gathered using genome-wide methods and identify additional hotspots and eQTLs.</p> <p>Conclusions</p> <p>New eQTLs and hotspots found with this method may represent regions of the genome or biological processes that are controlled through few relatively strong genetic interactions. These points of interest warrant experimental investigation.</p

Tidal Response of Mars Constrained From Laboratory-Based Viscoelastic Dissipation Models and Geophysical Data

We employ laboratory-based grain-size- and temperature-sensitive rheological models to 16 describe the viscoelastic behavior of terrestrial bodies with focus on Mars. Shear modulus 17 reduction and attenuation related to viscoelastic relaxation occur as a result of diffusion- 18 and dislocation-related creep and grain-boundary processes. We consider five rheological 19 models, including extended Burgers, Andrade, Sundberg-Cooper, a power-law approxima- 20 tion, and Maxwell, and determine Martian tidal response. However, the question of which 21 model provides the most appropriate description of dissipation in planetary bodies, re- 22 mains an open issue. To examine this, crust and mantle models (density and elasticity) are 23 computed self-consistently through phase equilibrium calculations as a function of pres- 24 sure, temperature, and bulk composition, whereas core properties are based on an Fe-FeS 25 parameterisation. We assess the compatibility of the viscoelastic models by inverting the 26 available geophysical data for Mars (tidal response and mean density and moment of in- 27 ertia) for temperature, elastic, and attenuation structure. Our results show that although 28 all viscoelastic models are consistent with data, their predictions for the tidal response at 29 other periods and harmonic degrees are distinct. The results also show that Maxwell is 30 only capable of fitting data for unrealistically low viscosities. Our approach can be used 31 quantitatively to distinguish between the viscoelastic models from seismic and/or tidal ob- 32 servations that will allow for improved constraints on interior structure (e.g., with InSight). 33 Finally, the methodology presented here is generally formulated and applicable to other so- 34 lar and extra-solar system bodies where the study of tidal dissipation presents an important 35 means for determining interior structure

The physiological basis of attentional modulation in extrastriate visual areas,

Substantial experimental evidence from humans and non-human primates implicates the extrastriate visual area V5 (located in the posterior region of the inferior temporal gyrus and sulcus) in motion processing and area V4 (located in the fusiform gyrus) in color processing The above studies show attentional modulation of stimulusevoked responses. Fewer studies have explicitly investigated attentional modulation of baseline activity. Macaque studies explored baseline shifts in neuronal responses in the context of working memory 8 . They found that both baseline activity and activity evoked by a moving stimulus appear to change with expectation. Even when subjects view a blank screen, baseline activity in 32% of V5 cells doubles. Using direction of motion as the matching criterion, this study employed a delayed match to sample task. Modulation of delay period or baseline activity was not related to specific information in the cue (direction), suggesting that this effect may be modulated, in part, by attention. When interpreting our results in relation to these findings, we assume that baseline attentional modulation is mediated by the same sort of tonic discharge associated with delay period activity evoked by working memory tasks. Monkey electrophysiology also shows that attention can modulate both baseline and stimulus evoked activity in V4, depending on the relative locations of visual stimuli within the cell&apos;s receptive field Enhanced baseline activity is taken to reflect attentional &apos;set&apos; or expectation, whereas changes in stimulus-evoked activity reflect changes in sensory processing 10 . However the functional significance of and relationship between changes in &apos;set&apos; and changes in evoked activity is unknown. Because of the long periods of time over which hemodynamic signals are integrated, it has been difficult to unambiguously dissociate activity due to attentional set from stimulus-evoked responses in human functional neuroimaging studies 15 . Here, by using a novel event-related protocol and fMRI, we show such a dissociation in V5 and V4, relating attentional set and evoked activity in accord with C. ([email protected]) Selective attention to color or motion enhances activity in specialized areas of extrastriate cortex, but mechanisms of attentional modulation remain unclear. By dissociating modulation of visually evoked transient activity from the baseline for a particular attentional set, human functional neuroimaging was used to investigate the physiological basis of such effects. Baseline activity in motion-and color-sensitive areas of extrastriate cortex was enhanced by selective attention to these attributes, even without moving or colored stimuli. Further, visually evoked responses increased along with baseline activity. These results are consistent with the hypothesis that attention modulates sensitivity of neuronal populations to inputs by changing background activity. &apos;Correct&apos; denotes events that the subject responded to correctly. &apos;Incorrect&apos; denotes false-positive responses

The prediction of fatigue using speech as a biosignal

Automatic systems for estimating operator fatigue have application in safety-critical environments. We develop and evaluate a system to detect fatigue from speech recordings collected from speakers kept awake over a 60-hour period. A binary classification system (fatigued/not-fatigued) based on time spent awake showed good discrimination, with 80 % unweighted accuracy using raw features, and 90 % with speaker-normalized features. We describe the data collection, feature analysis, machine learning and cross-validation used in the study. Results are promising for real-world applications in domains such as aerospace, transportation and mining where operators are in regular verbal communication as part of their normal working activities

Effect of layer thickness on the high temperature mechanical properties of Al/SiC nanolaminates

Composite laminates on the nanoscale have shown superior hardness and toughness, but little is known about their high temperature behavior. The mechanical properties (elastic modulus and hardness) were measured as a function of temperature by means of nanoindentation in Al/SiC nanolaminates, a model metal–ceramic nanolaminate fabricated by physical vapor deposition. The influence of the Al and SiC volume fraction and layer thicknesses was determined between room temperature and 150 °C and, the deformation modes were analyzed by transmission electron microscopy, using a focused ion beam to prepare cross-sections through selected indents. It was found that ambient temperature deformation was controlled by the plastic flow of the Al layers, constrained by the SiC, and the elastic bending of the SiC layers. The reduction in hardness with temperature showed evidence of the development of interface-mediated deformation mechanisms, which led to a clear influence of layer thickness on the hardness

Horizon effects with surface waves on moving water

Surface waves on a stationary flow of water are considered, in a linear model that includes the surface tension of the fluid. The resulting gravity-capillary waves experience a rich array of horizon effects when propagating against the flow. In some cases three horizons (points where the group velocity of the wave reverses) exist for waves with a single laboratory frequency. Some of these effects are familiar in fluid mechanics under the name of wave blocking, but other aspects, in particular waves with negative co-moving frequency and the Hawking effect, were overlooked until surface waves were investigated as examples of analogue gravity [Sch\"utzhold R and Unruh W G 2002 Phys. Rev. D 66 044019]. A comprehensive presentation of the various horizon effects for gravity-capillary waves is given, with emphasis on the deep water/short wavelength case kh>>1 where many analytical results can be derived. A similarity of the state space of the waves to that of a thermodynamic system is pointed out.Comment: 30 pages, 15 figures. Minor change

Bulk and surface switching in Mn-Fe-based Prussian Blue Analogues

Many Prussian Blue Analogues are known to show a thermally induced phase transition close to room temperature and a reversible, photo-induced phase transition at low temperatures. This work reports on magnetic measurements, X-ray photoemission and Raman spectroscopy on a particular class of these molecular heterobimetallic systems, specifically on Rb0.81Mn[Fe(CN)6]0.95_1.24H2O, Rb0.97Mn[Fe(CN)6]0.98_1.03H2O and Rb0.70Cu0.22Mn0.78[Fe(CN)6]0.86_2.05H2O, to investigate these transition phenomena both in the bulk of the material and at the sample surface. Results indicate a high degree of charge transfer in the bulk, while a substantially reduced conversion is found at the sample surface, even in case of a near perfect (Rb:Mn:Fe=1:1:1) stoichiometry. Thus, the intrinsic incompleteness of the charge transfer transition in these materials is found to be primarily due to surface reconstruction. Substitution of a large fraction of charge transfer active Mn ions by charge transfer inactive Cu ions leads to a proportional conversion reduction with respect to the maximum conversion that is still stoichiometrically possible and shows the charge transfer capability of metal centers to be quite robust upon inclusion of a neighboring impurity. Additionally, a 532 nm photo-induced metastable state, reminiscent of the high temperature Fe(III)Mn(II) ground state, is found at temperatures 50-100 K. The efficiency of photo-excitation to the metastable state is found to be maximized around 90 K. The photo-induced state is observed to relax to the low temperature Fe(II)Mn(III) ground state at a temperature of approximately 123 K.Comment: 12 pages, 8 figure