419 research outputs found

    Heads up! Dynamic Similitude for Perception with an Object Wielded by Head or Hand

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    Possibilities for behavior (i.e., affordances) can be perceived with units spanning anatomical components and external objects. For example, affordances for standing on an inclined surface can be perceived with an object held in the hand or attached to the head. We investigated whether these two person-plus-object perceptual systems exhibit the same pattern of nonlinear phase transitions in perception of this affordance. Blindfolded participants explored an inclined surface with a rod held in the hand or attached to the head and reported whether they could stand on that surface. Inclinations were presented in ascending or descending sequences. In both conditions, responses exhibited negative hysteresis – perceptual boundaries occurred at steeper angles for descending than for ascending sequences. The generalization of this pattern across components that differ in physiology, sensitivity, and experience is consistent with both the soft assembly of perceptual devices and with a dynamical systems perspective on perception of affordances

    Coregulator Control of Androgen Receptor Action by a Novel Nuclear Receptor-Binding Motif

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    The androgen receptor (AR) is a ligand-activated transcription factor that is essential for prostate cancer development. It is activated by androgens through its ligand-binding domain (LBD), which consists predominantly of 11 α-helices. Upon ligand binding, the last helix is reorganized to an agonist conformation termed activator function-2 (AF-2) for coactivator binding. Several coactivators bind to the AF-2 pocket through conserved LXXLL or FXXLF sequences to enhance the activity of the receptor. Recently, a small compound-binding surface adjacent to AF-2 has been identified as an allosteric modulator of the AF-2 activity and is termed binding function-3 (BF-3). However, the role of BF-3 in vivo is currently unknown, and little is understood about what proteins can bind to it. Here we demonstrate that a duplicated GARRPR motif at the N terminus of the cochaperone Bag-1L functions through the BF-3 pocket. These findings are supported by the fact that a selective BF-3 inhibitor or mutations within the BF-3 pocket abolish the interaction between the GARRPR motif(s) and the BF-3. Conversely, amino acid exchanges in the two GARRPR motifs of Bag-1L can impair the interaction between Bag-1L and AR without altering the ability of Bag-1L to bind to chromatin. Furthermore, the mutant Bag-1L increases androgen-dependent activation of a subset of AR targets in a genome-wide transcriptome analysis, demonstrating a repressive function of the GARRPR/BF-3 interaction. We have therefore identified GARRPR as a novel BF-3 regulatory sequence important for fine-tuning the activity of the AR

    Autocracy-Sustaining Versus Democratic Federalism:Explaining the Divergent Trajectories of Territorial Politics in Russia and Western Europe

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    This article provides a comparative assessment of territorial politics in Russia and Western Europe. The consolidation or deepening of regional autonomy in Western Europe contrasts with the transformation of Russia from a segmented and highly centrifugal state into a centralized authoritarian state in the course of just two decades. The consolidation of territorial politics in Western Europe is linked to the presence of endogenous safeguards that are built into their territorial constitutional designs and most importantly to the dynamics that emanate from multi-level party competition in the context of a liberal and multi-level democracy. In contrast, in Russia, neither endogenous safeguards nor multi-level party democracy play an important role in explaining the dynamics of Russian federalism, but who controls key state resources instead. We argue that under Putin power dependencies between the Russian center and the regions are strongest where regional democracy is at its weakest, thus producing ‘autocracy-sustaining’ instead of a democratic federation. By studying the relationship between federalism and democracy in cases where both concepts are mutually reinforcing (as in Western Europe) with the critical case of Russia where they are not, we question the widely held view that democracy is a necessary pre-condition for federalism.Peer reviewe

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Combined Cisplatinum and Laser Thermal Therapy for Palliation of Recurrent Head and Neck Tumors

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    In recent years endoscopically controlled laser-induced thermal therapy (LITT) has been increasingly accepted as a minimally invasive method for palliation of advanced or recurrent head and neck or gastrointestinal cancer. Previous studies have shown that adjuvant chemotherapy can potentiate endoscopic laser thermal ablation of obstructing tumors leading to improved palliation in advanced cancer patients. Eight patients with recurrent head and neck tumors volunteered to enroll as part of an ongoing phase II LITT clinical trial, and also elected to be treated with systemic chemotherapy (cisplatin, 80 mg/m2) followed 24 h later by palliative laser thermal ablation. Laser treatments were repeated in patients with residual disease or recurrence for a total of 27 LITT sessions. Four of the 8 patients treated with laser thermal chemotherapy remained alive after a median follow-up of 12 months. Of the 12 tumor sites treated, complete responses were located in the oral cavity (3), oropharynx (1), hypopharynx (1), maxillary sinus (1), and median survival for these patients was 9.5 months. This initial experience with cisplatinum-based laser chemotherapy indicates both safety and therapeutic potential for palliation of advanced head and neck cancer but this must be confirmed by longer follow-up in a larger cohort of patients

    Synthetic High Angular Momentum Spin Dynamics in a Microwave Oscillator

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    Spins and oscillators are foundational to much of physics and applied sciences. For quantum information, a spin 1/2 exemplifies the most basic unit, a qubit. High angular momentum spins (HAMSs) and harmonic oscillators provide multilevel manifolds which have the potential for hardware-efficient protected encodings of quantum information and simulation of many-body quantum systems. In this work, we demonstrate a new quantum control protocol that conceptually merges these disparate hardware platforms. Namely, we show how to modify a harmonic oscillator on demand to implement a continuous range of generators to accomplish linear and nonlinear HAMS dynamics. The spinlike dynamics are verified by demonstration of linear spin coherent [SU(2)] rotations, nonlinear spin rotations, and comparison to other manifolds like simply truncated oscillators. Our scheme allows universal control of a spin cat logical qubit encoding with interpretable drive pulses: We use linear operations to accomplish four logical gates and further show that nonlinear spin rotations can complete the logical gate set. Our results show how motion on a closed Hilbert space can be useful for quantum information processing and opens the door to superconducting circuit simulations of higher angular momentum quantum magnetism

    Interactions of anaerobic ammonium oxidizers and sulfide-oxidizing bacteria in a substrate-limited model system mimicking the marine environment

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    In nature anaerobic ammonium oxidation (anammox) and denitrification processes convert fixed nitrogen to gaseous nitrogen compounds, which are then released to the atmosphere. While anammox bacteria produce N2 from ammonium and nitrite, in the denitrification process nitrate and nitrite are converted to N2 and the greenhouse gas nitrous oxide (N2O). Furthermore, nitrite needed by the anammox bacteria can be supplied by nitrate reduction to nitrite. Consequently, the interplay between nitrogen-transforming microorganisms control the amount of harmless N2 or the greenhouse gas N2O released to the atmosphere. Therefore, it is important to understand the interactions of these microorganisms in the natural environment, where dynamic conditions result in fluctuating substrate concentrations. Here, we studied the interactions between the sulfide-oxidizing denitrifier Sedimenticola selenatireducens and the anammox bacterium Scalindua brodae in a bioreactor mimicking the marine environment by creating sulfide, ammonium and nitrate limitation in distinct operational phases. Through a microbial interaction, Se. selenatireducens reduced nitrate to nitrite, which together with the supplied ammonium was converted to N2 by Sc. Brodae. Using comparative transcriptomics, we determined that Sc. Brodae and Se. selenatireducens had significant responses to ammonium and nitrate limitation, respectively, indicating that the activities of these microorganisms are regulated by different nitrogen compounds
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