Locality via Global Ties: Stability of the 2-Core Against Misspecification

For many random graph models, the analysis of a related birth process suggests local sampling algorithms for the size of, e.g., the giant connected component, the $k$-core, the size and probability of an epidemic outbreak, etc. In this paper, we study the question of when these algorithms are robust against misspecification of the graph model, for the special case of the 2-core. We show that, for locally converging graphs with bounded average degrees, under a weak notion of expansion, a local sampling algorithm provides robust estimates for the size of both the 2-core and its largest component. Our weak notion of expansion generalizes the classical definition of expansion, while holding for many well-studied random graph models. Our method involves a two-step sprinkling argument. In the first step, we use sprinkling to establish the existence of a non-empty $2$-core inside the giant, while in the second, we use this non-empty $2$-core as seed for a second sprinkling argument to establish that the giant contains a linear sized $2$-core. The second step is based on a novel coloring scheme for the vertices in the tree-part. Our algorithmic results follow from the structural properties for the $2$-core established in the course of our sprinkling arguments. The run-time of our local algorithm is constant independent of the graph size, with the value of the constant depending on the desired asymptotic accuracy $\epsilon$. But given the existential nature of local limits, our arguments do not give any bound on the functional dependence of this constant on $\epsilon$, nor do they give a bound on how large the graph has to be for the asymptotic additive error bound $\epsilon$ to hold

What role does the palate play in speech motor control? Insights from tongue kinematics for German alveolar obstruents

By means of simultaneous EMMA and EPG recordings, we investigated tongue tip kinematics and tongue palate contact patterns for four German speakers in order to compare production strategies of alveolar stops with fricatives. For alveolar stops versus fricatives, two different control strategies were hypothesized: a target above the contact location for alveolar stops resulting in a collision of the tongue tip at the palate as opposed to a precise positioning of the tongue at the lateral margins at the palate for alveolar fricatives. Additionally, we suspected differences between stops and fricatives with respect to anterior and lateral palate contacts and their influence on tongue kinematics. Results of this study confirmed two different control strategies for alveolar stops and fricatives by means of significant differences in movement amplitude, velocity, and duration of the closing gesture, the amplitude of deceleration peaks, tongue tip movement during acoustically defined closure and constriction, and maximal anterior contact during closure. Additionally, results for speaker dependent mechanisms were related to the subject's coronal palatal shape

Relying on critical articulators to estimate vocal tract spectra in an articulatory-acoustic database

We present a new phone-dependent feature weighting scheme that can be used to map articulatory configurations (e.g. EMA) onto vocal tract spectra (e.g. MFCC) through table lookup. The approach consists of assigning feature weights according to a feature's ability to predict the acoustic distance between frames. Since an articulator's predictive accuracy is phone-dependent (e.g., lip location is a better predictor for bilabial sounds than for palatal sounds), a unique weight vector is found for each phone. Inspection of the weights reveals a correspondence with the expected critical articulators for many phones. The proposed method reduces overall cepstral error by 6\% when compared to a uniform weighting scheme. Vowels show the greatest benefit, though improvements occur for 80\% of the tested phones

Saccades to a remembered location elicit spatially specific activation in human retinotopic visual cortex

The possible impact upon human visual cortex from saccades to remembered target locations was investigated using functional magnetic resonance imaging (fMRI). A specific location in the upper-right or upper-left visual quadrant served as the saccadic target. After a delay of 2,400 msec, an auditory signal indicated whether to execute a saccade to that location (go trial) or to cancel the saccade and remain centrally fixated (no-go). Group fMRI analysis revealed activation specific to the remembered target location for executed saccades, in the contralateral lingual gyrus. No-go trials produced similar, albeit significantly reduced, effects. Individual retinotopic mapping confirmed that on go trials, quadrant-specific activations arose in those parts of ventral V1, V2, and V3 that coded the target location for the saccade, whereas on no-go trials, only the corresponding parts of V2 and V3 were significantly activated. These results indicate that a spatial-motor saccadic task (i.e., making an eye movement to a remembered location) is sufficient to activate retinotopic visual cortex spatially corresponding to the target location, and that this activation is also present (though reduced) when no saccade is executed. We discuss the implications of finding that saccades to remembered locations can affect early visual cortex, not just those structures conventionally associated with eye movements, in relation to recent ideas about attention, spatial working memory, and the notion that recently activated representations can be "refreshed" when needed

Hydrodynamic Performance of Aquatic Flapping: Efficiency of Underwater Flight in the Manta

The manta is the largest marine organism to swim by dorsoventral oscillation (flapping) of the pectoral fins. The manta has been considered to swim with a high efficiency stroke, but this assertion has not been previously examined. The oscillatory swimming strokes of the manta were examined by detailing the kinematics of the pectoral fin movements swimming over a range of speeds and by analyzing simulations based on computational fluid dynamic potential flow and viscous models. These analyses showed that the fin movements are asymmetrical up- and downstrokes with both spanwise and chordwise waves interposed into the flapping motions. These motions produce complex three-dimensional flow patterns. The net thrust for propulsion was produced from the distal half of the fins. The vortex flow pattern and high propulsive efficiency of 89% were associated with Strouhal numbers within the optimal range (0.2–0.4) for rays swimming at routine and high speeds. Analysis of the swimming pattern of the manta provided a baseline for creation of a bio-inspired underwater vehicle, MantaBot

High Pressure Behaviour of the Organic Semiconductor Salt (TTF-BTD)2I3.

: This study focuses on the effect of structure compression and cooling on the stereoelectronic properties of the planar π-conjugated TTF-BTD (TTF = tetrathiafulvalene; BTD = 2,1,3-benzothiadiazole) molecule, a prototypical example in which an electron-donor moiety is compactly annulated to an electron-acceptor moiety. Its partially oxidised iodine salt (TTF-BTD)2I3 is a crystalline semiconductor featuring segregated columns of TTF+0.5 units stacked via alternating short and long π-π interactions. We studied TTF-BTD at temperatures ranging from 300 K to 90 K and at pressures up to 7.5 GPa, using both X-ray diffraction and Raman spectroscopy to determine the properties of the compressed samples. Periodic DFT calculations and several theoretical tools were employed to characterize the calculated structural modifications and to predict the structural changes up to 60 GPa. The existence of an unprecedented new phase is predicted above 20 GPa, following a covalent bond formation between two neighbouring TTF-BTD units

Selective release of a potent anticancer agent from a supramolecular hydrogel using green light

Light-triggered drug release from hydrogels is a promising method to improve efficiency of antitumor treatment, as an alternative to existing photodynamic therapies. Here we report a photochromic supramolecular low-MW hydrogel that can quickly and selectively release a physically encapsulated potent anticancer agent upon green light irradiation under physiological conditions

The Control of Token-toToken Variability: an Experimental and Modeling Study

Abstract. The articulatory token-to-token variability in the production of German vowels is investigated with simultaneous EMMA and EPG recordings. The potential role of physical constraints, such as the contacts between tongue and palate measured by EPG, and the biomechanical properties of the tongue, simulated with a 2D finite element model is evaluated. Our results suggest that the control of high front vowels makes use of the palatal contacts, while the variability of low vowels is essentially oriented along the main axis of deformation of the tongue, the high/front-to-low/back direction

BCL6 enables Ph+ acute lymphoblastic leukaemia cells to survive BCR-ABL1 kinase inhibition.

Tyrosine kinase inhibitors (TKIs) are widely used to treat patients with leukaemia driven by BCR-ABL1 (ref. 1) and other oncogenic tyrosine kinases. Recent efforts have focused on developing more potent TKIs that also inhibit mutant tyrosine kinases. However, even effective TKIs typically fail to eradicate leukaemia-initiating cells (LICs), which often cause recurrence of leukaemia after initially successful treatment. Here we report the discovery of a novel mechanism of drug resistance, which is based on protective feedback signalling of leukaemia cells in response to treatment with TKI. We identify BCL6 as a central component of this drug-resistance pathway and demonstrate that targeted inhibition of BCL6 leads to eradication of drug-resistant and leukaemia-initiating subclones