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Sylvia L R Wood, Jeanine M Rhemtulla, Oliver T Coomes
In the study of shifting cultivation systems, fallow duration is seen as the key determinant of vegetation and soil dynamics: long fallows renew soil fertility, biomass and biodiversity. However, long fallow systems are increasingly replaced around the world with short-medium fallow systems, and awareness is growing of the need to look across multiple (not just single) crop-fallow cycles to accurately understand observed soil and vegetation patterns. In a study from Peru that builds on field-level land-use histories (50+ years), we found that over multiple crop-fallow cycles, farmer's cropping practices mattered more than fallow duration for biodiversity and soil fertility...
October 22, 2016: Ecological Applications: a Publication of the Ecological Society of America
Alexis V Mickelson, Sampath K Gollapudi, Murali Chandra
The present study investigated the functional consequences of the human hypertrophic cardiomyopathy (HCM) mutation, A28V, in cardiac troponin T (TnT). The A28V mutation is located within the N-terminus of TnT, a region known to be important for full activation of cardiac thin filaments. The functional consequences of the A28V mutation in TnT remain unknown. Given how α- and β-myosin heavy chain (MHC) isoforms differently alter the effect of the N-terminus of TnT, we hypothesized that the A28V-induced effects would be differently modulated by α- and β-MHC isoforms...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Charlotte L George, Matthew T Birnie, Benjamin Flynn, Yvonne Kershaw, Stafford L Lightman, Becky L Conway-Campbell
In this paper we report differential decoding of the ultradian corticosterone signal by glucocorticoid target tissues. Pulsatile corticosterone replacement in adrenalectomised rats resulted in different dynamics of Sgk1 mRNA production, with a distinct pulsatile mRNA induction profile observed in the pituitary in contrast to a non-pulsatile induction in the prefrontal cortex. We further report the first evidence for pulsatile transcriptional repression of a glucocorticoid-target gene in vivo, with pulsatile regulation of Pomc transcription in pituitary...
October 18, 2016: Molecular and Cellular Endocrinology
Nicoletta Bobola, Samir Merabet
Homeodomain proteins are evolutionary conserved proteins present in the entire eukaryote kingdom. They execute functions that are essential for life, both in developing and adult organisms. Most homeodomain proteins act as transcription factors and bind DNA to control the activity of other genes. In contrast to their similar DNA binding specificity, homeodomain proteins execute highly diverse and context-dependent functions. Several factors, including genome accessibility, DNA shape, combinatorial binding and the ability to interact with many transcriptional partners, diversify the activity of homeodomain proteins and culminate in the activation of highly dynamic, context-specific transcriptional programs...
October 18, 2016: Current Opinion in Genetics & Development
Shobini Jayaraman, Jose Luis Sánchez-Quesada, Olga Gursky
Lipids in the body are transported via lipoproteins that are nanoparticles comprised of lipids and amphipathic proteins termed apolipoproteins. This family of lipid surface-binding proteins is over-represented in human amyloid diseases. In particular, all major proteins of high-density lipoproteins (HDL), including apoA-I, apoA-II and serum amyloid A, can cause systemic amyloidoses in humans upon protein mutations, post-translational modifications or overproduction. Here, we begin to explore how the HDL lipid composition influences amyloid deposition by apoA-I and related proteins...
October 18, 2016: Biochimica et Biophysica Acta
Richard A Manderville, Stacey D Wetmore
The formation of DNA adducts by the attack of intermediates derived from toxic substances at the C8 position of 2-deoxyguanosine (dG) is a common damaging event. Although the majority of studies on C8-dG adducts have focused on lesions containing a C8-N-C tether between the bulky moiety and the nucleobase, the formation of O-linked lesions with a similar tether topology and C-linked adducts involving direct C8-C connectivity have also been uncovered. Several studies have been done to try to better understand the structural impact and mutagenicity of O-linked and C-linked aryl C8-dG adducts, including lesions arising from unsubstituted and chloro substituted phenols, and the food mutagen ochratoxin A (OTA)...
October 21, 2016: Chemical Research in Toxicology
Kevin Kalisz, Ji Buethe, Sachin S Saboo, Suhny Abbara, Sandra Halliburton, Prabhakar Rajiah
Computed tomography is vulnerable to a wide variety of artifacts, including patient- and technique-specific artifacts, some of which are unique to imaging of the heart. Motion is the most common source of artifacts and can be caused by patient, cardiac, or respiratory motion. Cardiac motion artifacts can be reduced by decreasing the heart rate and variability and the duration of data acquisition; adjusting the placement of the data window within a cardiac cycle; performing single-heartbeat scanning; and using multisegment reconstruction, motion-correction algorithms, and electrocardiographic editing...
October 21, 2016: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Dominik S Wild, Sarang Gopalakrishnan, Michael Knap, Norman Y Yao, Mikhail D Lukin
Adiabatic quantum algorithms represent a promising approach to universal quantum computation. In isolated systems, a key limitation to such algorithms is the presence of avoided level crossings, where gaps become extremely small. In open quantum systems, the fundamental robustness of adiabatic algorithms remains unresolved. Here, we study the dynamics near an avoided level crossing associated with the adiabatic quantum search algorithm, when the system is coupled to a generic environment. At zero temperature, we find that the algorithm remains scalable provided the noise spectral density of the environment decays sufficiently fast at low frequencies...
October 7, 2016: Physical Review Letters
Gil Henkin, Daniel Berard, Francis Stabile, Marjan Shayegan, Jason S Leith, Sabrina R Leslie
We present a dynamically adjustable nanofluidic platform for formatting the conformations of and visualizing the interaction kinetics between biomolecules in solution, offering new time resolution and control of the reaction processes. This platform extends Convex Lens-induced Confinement (CLiC), a technique for imaging molecules under confinement, by introducing a system for in-situ modification of the chemical environment; this system uses a deep microchannel to diffusively exchange reagents within the nanoscale imaging region, whose height is fixed by a nanopost array...
October 21, 2016: Analytical Chemistry
Shui'er Han, Claudia Lunghi, David Alais
Continuous flash suppression (CFS) is a psychophysical technique where a rapidly changing Mondrian pattern viewed by one eye suppresses the target in the other eye for several seconds. Despite the widespread use of CFS to study unconscious visual processes, the temporal tuning of CFS suppression is currently unknown. In the present study we used spatiotemporally filtered dynamic noise as masking stimuli to probe the temporal characteristics of CFS. Surprisingly, we find that suppression in CFS peaks very prominently at approximately 1 Hz, well below the rates typically used in CFS studies (10 Hz or more)...
October 21, 2016: Scientific Reports
Yu Harabuchi, Rina Yamamoto, Satoshi Maeda, Satoshi Takeuchi, Tahei Tahara, Tetsuya Taketsugu
Ab initio molecular dynamics (AIMD) simulations were carried out for *-excited 1,1'-dimethylstilbene (dmSB) at the spin-flip time-dependent density functional theory (SF-TDDFT) level with the TSF-index technique, to get insights into the substitution effects on the photoisomerization dynamics of stilbene (SB). It is found that the reaction path from the Franck-Condon structure of cis-dmSB is oriented toward the 4,4-dihydrophenanthrene (DHP) side from the beginning, which is in contrast to the case of SB where the pathway is oriented toward the twist-side in the initial stage...
October 21, 2016: Journal of Physical Chemistry. A
Sungheon Gene Kim, Melanie Freed, Ana Paula Klautau Leite, Jin Zhang, Claudia Seuss, Linda Moy
PURPOSE: To assess the diagnostic utility of contrast kinetic analysis for breast lesions and background parenchyma of women undergoing MRI-guided biopsies, for whom standard clinical analysis had failed to separate benign and malignant lesions. MATERIALS AND METHODS: This study included 115 women who had indeterminate lesions based on routine diagnostic breast MRI exams and underwent an MRI (3 Tesla) -guided biopsy of one or more lesions suspicious for breast cancer...
October 20, 2016: Journal of Magnetic Resonance Imaging: JMRI
Rachel Grossman, Nir Shimony, Dror Shir, Tal Gonen, Razi Sitt, Tali Jonas Kimchi, Carmit Ben Harosh, Zvi Ram
BACKGROUND: The extent of tumor resection (EOTR) calculated by enhanced T1 changes in glioblastomas has been previously reported to predict survival. However, fluid-attenuated inversion recovery (FLAIR) volume may better represent tumor burden. In this study, we report the first assessment of the dynamics of FLAIR volume changes over time as a predictive variable for post-resection overall survival (OS). METHODS: Contemporary data from 103 consecutive patients with complete imaging and clinical data who underwent resection of newly diagnosed glioblastoma followed by the Stupp protocol between 2010 and 2013 were analyzed...
October 20, 2016: Annals of Surgical Oncology
Razia S Shaik, Xiaocheng Zhu, David R Clements, Leslie A Weston
Part of the challenge in dealing with invasive plant species is that they seldom represent a uniform, static entity. Often, an accurate understanding of the history of plant introduction and knowledge of the real levels of genetic diversity present in species and populations of importance is lacking. Currently, the role of genetic diversity in promoting the successful establishment of invasive plants is not well defined. Genetic profiling of invasive plants should enhance our understanding of the dynamics of colonization in the invaded range...
2016: Conservation Physiology
P Moisset de Espanés, A Osses, I Rapaport
Fixed points are fundamental states in any dynamical system. In the case of gene regulatory networks (GRNs) they correspond to stable genes profiles associated to the various cell types. We use Kauffman's approach to model GRNs with random Boolean networks (RBNs). In this paper we explore how the topology affects the distribution of the number of fixed points in randomly generated networks. We also study the size of the basins of attraction of these fixed points if we assume the α-asynchronous dynamics (where every node is updated independently with probability 0≤α≤1)...
October 17, 2016: Bio Systems
Young S Kang, Frederick Rueggeberg, Van Ramos
STATEMENT OF PROBLEM: Polyvinyl siloxane (PVS) impression materials must be cold disinfected before cast pouring to prevent cross-contamination among personnel and patients. However, disinfection may affect the ability of PVS impression materials to provide bubble-free stone surfaces because of the removal of surfactants. PURPOSE: The purpose of this in vitro study was to compare the water contact angles of a PVS impression material treated with either a quaternary ammonium-based (QAB) (DisCide Ultra) or a chlorine-based (CLB) (Dispatch) disinfectant for various exposure times...
October 17, 2016: Journal of Prosthetic Dentistry
Zhizhao Che, Panagiotis E Theodorakis
Surface nanobubbles are stable gaseous phases in liquids that form on solid substrates. While their existence has been confirmed, there are many open questions related to their formation and dissolution processes along with their structures and properties, which are difficult to investigate experimentally. To address these issues, we carried out molecular dynamics simulations based on atomistic force fields for systems comprised of water, air (N2 and O2), and a Highly Oriented Pyrolytic Graphite (HOPG) substrate...
October 14, 2016: Journal of Colloid and Interface Science
David M Bogner, Mark A Kaemingk, Melissa R Wuellner
Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching) could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus) annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A.) Sandhill lake...
2016: PloS One
Christine L Madliger, Oliver P Love
The application of physiological measures to conservation monitoring has been gaining momentum and, while a suite of physiological traits are available to ascertain disturbance and condition in wildlife populations, glucocorticoids (i.e., GCs; cortisol and corticosterone) are the most heavily employed. The interpretation of GC levels as sensitive indicators of population change necessitates that GCs and metrics of population persistence are linked. However, the relationship between GCs and fitness may be highly context-dependent, changing direction, or significance, depending on the GC measure, fitness metric, life history stage, or other intrinsic and extrinsic contexts considered...
July 27, 2016: Ecological Applications: a Publication of the Ecological Society of America
Bobby A Tajudeen, Zachary D Taylor, James Garritano, Harrison Cheng, Aidan Pearigen, Adria J Sherman, Fernando Palma-Diaz, Pratik Mishra, Siddharth Bhargava, Julianna Pesce, Irene Kim, Christine Sebastian, Ali Razfar, Asael Papour, Oscar Stafsudd, Warren Grundfest, Maie St John
BACKGROUND: Head and neck squamous cell carcinomas (HNSCCs) are debilitating diseases for which a patient's prognosis depends heavily on complete tumor resection. Currently, the surgeon's fingers determine the location of tissue margins. This study evaluated the diagnostic utility of a novel imaging modality, dynamic optical contrast imaging (DOCI), in the detection of HNSCC. This system generates contrast by illuminating the tissue with pulsed light and detecting variations in endogenous fluorophore lifetimes...
October 20, 2016: Cancer
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