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Biological motion

Titiwat Sungkaworn, Marie-Lise Jobin, Krzysztof Burnecki, Aleksander Weron, Martin J Lohse, Davide Calebiro
G-protein-coupled receptors mediate the biological effects of many hormones and neurotransmitters and are important pharmacological targets. They transmit their signals to the cell interior by interacting with G proteins. However, it is unclear how receptors and G proteins meet, interact and couple. Here we analyse the concerted motion of G-protein-coupled receptors and G proteins on the plasma membrane and provide a quantitative model that reveals the key factors that underlie the high spatiotemporal complexity of their interactions...
October 18, 2017: Nature
Charles Reilly, Donald E Ingber
Many have recognized the potential value of facilitating activities that span the art-science interface for the benefit of society; however, there are few examples that demonstrate how pursuit of an artistic agenda can lead to scientific insights. Here, we describe how we set out to produce an entertaining short film depicting the fertilization of the egg by sperm as a parody of a preview for another Star Wars movie to excite the public about science, but ended up developing a simulation tool for multiscale modeling...
October 18, 2017: ACS Nano
James P McLean, Yuye Ling, Christine P Hendon
Sparse representation theory is an exciting area of research with recent applications in medical imaging and detection, segmentation, and quantitative analysis of biological processes. We present a variant on the robust-principal component analysis (RPCA) algorithm, called frequency constrained RPCA (FC-RPCA), for selectively segmenting dynamic phenomena that exhibit spectra within a user-defined range of frequencies. The algorithm lacks subjective parameter tuning and demonstrates robust segmentation in datasets containing multiple motion sources and high amplitude noise...
October 16, 2017: Optics Express
Souichi Sakamoto, Yoshitaka Tanimura
We theoretically investigate an exciton-coupled electron transfer (XCET) process that is conversion of an exciton into a charge transfer state. This conversion happens in an exciton transfer (XT) process, and the electron moves away in an electron transfer(ET) process in multiple environments (baths). This XCET process plays an essential role in the harvesting of solar energy in biological and photovoltaic materials. We develop a practical theoretical model to study the efficiency of XCET process that occurs either in consecutive or concerted processes under the influence of non-Markovian baths...
October 17, 2017: Journal of Physical Chemistry Letters
Robert U Hartzler, Stephen S Burkhart
Superior capsular reconstruction (SCR) of the shoulder has recently gained popularity as an option for joint-preserving shoulder surgery for patients with an irreparable rotator cuff tear. In the absence of glenohumeral arthritis, rotator cuff tear irreparability should only be diagnosed for most patients after a careful diagnostic arthroscopy. Superior capsular reconstruction adds biological, passive, superior constraint to the glenohumeral joint, thereby optimizing the rotator cuff force couples and improving joint kinematics...
October 1, 2017: Orthopedics
Ilaria Passacantilli, Paola Frisone, Elisa De Paola, Marco Fidaleo, Maria Paola Paronetto
Ewing sarcomas (ES) are biologically aggressive tumors of bone and soft tissues for which no cure is currently available. Most ES patients do not respond to chemotherapeutic treatments or acquire resistance. Since the PI3K/AKT/mTOR axis is often deregulated in ES, its inhibition offers therapeutic perspective for these aggressive tumors. Herein, by using splicing sensitive arrays, we have uncovered an extensive splicing program activated upon inhibition of the PI3K/AKT/mTOR signaling pathway by BEZ235. Bioinformatics analyses identified hnRNPM as a key factor in this response...
October 3, 2017: Nucleic Acids Research
Mário Saleiro, Kasim Terzić, J M F Rodrigues, J M H du Buf
Learning robust keypoint descriptors has become an active research area in the past decade. Matching local features is not only important for computational applications, but may also play an important role in early biological vision for disparity and motion processing. Although there were already some floating-point descriptors like SIFT and SURF that can yield high matching rates, the need for better and faster descriptors for real-time applications and embedded devices with low computational power led to the development of binary descriptors, which are usually much faster to compute and to match...
October 12, 2017: Bio Systems
Hannah Lee, Jejoong Kim
Impaired working memory (WM) is a core cognitive deficit in schizophrenia. Nevertheless, past studies have reported that patients may also benefit from increasing salience of memory stimuli. Such efficient encoding largely depends upon precise perception. Thus an investigation on the relationship between perceptual processing and WM would be worthwhile. Here, we used biological motion (BM), a socially relevant stimulus that schizophrenics have difficulty discriminating from similar meaningless motions, in a delayed-response task...
2017: PloS One
Martijn Tros, Linli Zheng, Johannes Hunger, Mischa Bonn, Daniel Bonn, Gertien J Smits, Sander Woutersen
Cells are extremely crowded, and a central question in biology is how this affects the intracellular water. Here, we use ultrafast vibrational spectroscopy and dielectric-relaxation spectroscopy to observe the random orientational motion of water molecules inside living cells of three prototypical organisms: Escherichia coli, Saccharomyces cerevisiae (yeast), and spores of Bacillus subtilis. In all three organisms, most of the intracellular water exhibits the same random orientational motion as neat water (characteristic time constants ~9 and ~2 ps for the first-order and second-order orientational correlation functions), whereas a smaller fraction exhibits slower orientational dynamics...
October 12, 2017: Nature Communications
Qinghua Liao, Anna Pabis, Birgit Strodel, Shina Caroline Lynn Kamerlin
Modeling metalloproteins often requires classical molecular dynamics (MD) simulations in order to capture their relevant motions, which in turn necessitates reliable descriptions of the metal centers involved. One of the most successful approaches to date is provided by the "cationic dummy model", where the positive charge of the metal ion is transferred towards dummy particles that are bonded to the central metal ion in a pre-defined coordination geometry. While this approach allows for ligand exchange, and captures the correct electrostatics as demonstrated for different divalent metal ions, current dummy models neglect ion-induced dipole interactions...
October 12, 2017: Journal of Physical Chemistry Letters
Han-Yuan Liu, Wei-Liang Chen, Christopher Kemper Ober, Susan Daniel
Reconstituted supported lipid bilayers (SLB) are widely used as in vitro cell-surface models because they are compatible with a variety of surface based analytical techniques. However, one of the challenges of using SLBs as a model of the cell surface is the limited complexity in membrane composition, including the incorporation of transmembrane proteins and lipid diversity that may impact the activity of those proteins. Additionally, it is challenging to preserve the transmembrane protein native orientation, function, and mobility in SLBs...
October 11, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Byung Ho Lee, Sangjae Seo, Min Hyeok Kim, Youngjin Kim, Soojin Jo, Moon-Ki Choi, Hoomin Lee, Jae Boong Choi, Moon Ki Kim
The biological function of proteins is closely related to its structural motion. For instance, structurally misfolded proteins do not function properly. Although we are able to experimentally obtain structural information on proteins, it is still challenging to capture their dynamics, such as transition processes. Therefore, we need a simulation method to predict the transition pathways of a protein in order to understand and study large functional deformations. Here, we present a new simulation method called normal mode-guided elastic network interpolation (NGENI) that performs normal modes analysis iteratively to predict transition pathways of proteins...
2017: PloS One
Marta Scali, Tim Philipp Pusch, Paul Breedveld, D Dodou
Flexible steerable needles have the potential to allow surgeons to reach deep targets inside the human body with higher accuracy than rigid needles do. Furthermore, by maneuvering around critical anatomical structures, steerable needles could limit the risk of tissue damage. However, the design of a thin needle (e.g., diameter under 2 mm) with a multi-direction steering mechanism is challenging. The goal of this paper is to outline the design and experimental evaluation of a biologically inspired needle with a diameter under 2 mm that advances through straight and curved trajectories in a soft substrate without being pushed, without buckling, and without the need of axial rotation...
October 11, 2017: Bioinspiration & Biomimetics
Varsha S Godakhindi, Peiyuan Kang, Maud Serre, Naga Aravind Revuru, Jesse Minghao Zou, Michael Robert Roner, Ruth Levitz, Jeffrey Kahn, Jaona Randrianalisoa, Zhenpeng Qin
Gold nanoparticle (GNP)-based aggregation assay is simple, fast, and employs a colorimetric detection method. Although previous studies have reported using GNP-based colorimetric assay to detect biological and chemical targets, a mechanistic and quantitative understanding of the assay and effects of GNP parameters on the assay performance is lacking. In this work, we investigated this important aspect of the GNP aggregation assay including effects of GNP concentration and size, on the assay performance to detect malarial DNA...
October 10, 2017: ACS Sensors
Animesh Halder, Baishakhi Saha, Pabitra Maity, Gopinatha Suresh Kumar, Deepak Kumar Sinha, Sanat Karmakar
We have studied the effect of composition and the phase state of phospholipid membranes on the emission spectrum, anisotropy and lifetime of a lipophilic fluorescence probe nile red. Fluorescence spectrum of nile red in membranes containing cholesterol has also been investigated in order to get insights into the influence of cholesterol on the phospholipid membranes. Maximum emission wavelength (λem) of nile red in the fluid phase of saturated and unsaturated phospholipids was found to differ by ~10nm. The λem was also found to be independent of chain length and charge of the membrane...
October 5, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
David Ahmedt-Aristizabal, Clinton Fookes, Sasha Dionisio, Kien Nguyen, João Paulo S Cunha, Sridha Sridharan
Epilepsy being one of the most prevalent neurological disorders, affecting approximately 50 million people worldwide, and with almost 30-40% of patients experiencing partial epilepsy being nonresponsive to medication, epilepsy surgery is widely accepted as an effective therapeutic option. Presurgical evaluation has advanced significantly using noninvasive techniques based on video monitoring, neuroimaging, and electrophysiological and neuropsychological tests; however, certain clinical settings call for invasive intracranial recordings such as stereoelectroencephalography (SEEG), aiming to accurately map the eloquent brain networks involved during a seizure...
October 9, 2017: Epilepsia
Thomas Stone, Barbara Webb, Andrea Adden, Nicolai Ben Weddig, Anna Honkanen, Rachel Templin, William Wcislo, Luca Scimeca, Eric Warrant, Stanley Heinze
Path integration is a widespread navigational strategy in which directional changes and distance covered are continuously integrated on an outward journey, enabling a straight-line return to home. Bees use vision for this task-a celestial-cue-based visual compass and an optic-flow-based visual odometer-but the underlying neural integration mechanisms are unknown. Using intracellular electrophysiology, we show that polarized-light-based compass neurons and optic-flow-based speed-encoding neurons converge in the central complex of the bee brain, and through block-face electron microscopy, we identify potential integrator cells...
October 4, 2017: Current Biology: CB
Elena Biselli, Elena Agliari, Adriano Barra, Francesca Romana Bertani, Annamaria Gerardino, Adele De Ninno, Arianna Mencattini, Davide Di Giuseppe, Fabrizio Mattei, Giovanna Schiavoni, Valeria Lucarini, Erika Vacchelli, Guido Kroemer, Corrado Di Natale, Eugenio Martinelli, Luca Businaro
In this paper we discuss the applicability of numerical descriptors and statistical physics concepts to characterize complex biological systems observed at microscopic level through organ on chip approach. To this end, we employ data collected on a microfluidic platform in which leukocytes can move through suitably built channels toward their target. Leukocyte behavior is recorded by standard time lapse imaging. In particular, we analyze three groups of human peripheral blood mononuclear cells (PBMC): heterozygous mutants (in which only one copy of the FPR1 gene is normal), homozygous mutants (in which both alleles encoding FPR1 are loss-of-function variants) and cells from 'wild type' donors (with normal expression of FPR1)...
October 6, 2017: Scientific Reports
Marina A Pavlova, Michael Erb, Gisela E Hagberg, Joana Loureiro, Alexander N Sokolov, Klaus Scheffler
Body motion delivers a wealth of socially relevant information. Yet display inversion severely impedes biological motion (BM) processing. It is largely unknown how the brain circuits for BM are affected by display inversion. As upright and upside-down point-light BM displays are similar, we addressed this issue by using ultrahigh field functional MRI at 9.4 T providing for high sensitivity and spatial resolution. Whole-brain analysis along with exploration of the temporal dynamics of the blood-oxygen-level-dependent response reveals that in the left hemisphere, inverted BM activates anterior networks likely engaged in decision making and cognitive control, whereas readily recognizable upright BM activates posterior areas solely...
July 10, 2017: Cerebral Cortex
Giorgia Martini, Simona Campus, Raffeiner Bernd, Gianluca Boscarol, Alessandra Meneghel, Francesco Zulian
Pansclerotic morphoea (PM) is a subtype of juvenile localised scleroderma characterised by severe course with generalised full-thickness skin involvement and possible growth and functional impairment. PM treatment comprises a combination of immunosuppressive agents such as corticosteroids, methotrexate, mycophenolate mofetil, PUVA and antithymocyte globulin and biological agents used in off-label. A possible role of IL-6 in the regulation of firoblast differentiation and stimulation of collagen synthesis has been suggested and in patients with systemic sclerosis (SSc) the treatment with tocilizumab (TCZ) was associated to improvement of skin thickness and joint motion...
September 2017: Clinical and Experimental Rheumatology
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