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https://www.readbyqxmd.com/read/28822291/highly-absorbing-multispectral-near-infrared-polymer-nanoparticles-from-one-conjugated-backbone-for-photoacoustic-imaging-and-photothermal-therapy
#1
Haobin Chen, Jian Zhang, Kaiwen Chang, Xiaoju Men, Xiaofeng Fang, Libo Zhou, Dongliang Li, Duyang Gao, Shengyan Yin, Xuanjun Zhang, Zhen Yuan, Changfeng Wu
Semiconducting polymers with specific absorption are useful in various applications, including organic optoelectronics, optical imaging, and nanomedicine. However, the optical absorption of a semiconducting polymer with a determined structure is hardly tunable when compared with that of inorganic semiconductors. In this work, we show that the optical absorption of polymer nanoparticles from one conjugated backbone can be effectively tuned through judicious design of the particle morphology and the persistence length of polymers...
August 12, 2017: Biomaterials
https://www.readbyqxmd.com/read/28821757/dated-phylogeny-and-dispersal-history-of-the-butterfly-subfamily-nymphalinae-lepidoptera-nymphalidae
#2
Chengyong Su, Qinghui Shi, Xiaoyan Sun, Junye Ma, Chunxiang Li, Jiasheng Hao, Qun Yang
The origin and dispersal history of the large butterfly subfamily Nymphalinae are not fully understood, due to internal phylogenetic and time calibration issues. We conducted phylogenetic and dating analyses using mitochondrial and nuclear genes of biogeographically diverse groups of the Nymphalinae in order to resolve some controversial relationships and the paleobiogeographic pattern of the subfamily. Our results support the sister relationship of Vanessa (Tribe Nymphalini) and the Nymphalis-group, and the grouping of the three old-world genera (Rhinopalpa, Kallimoides and Vanessula) within Tribe Victorinini...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821186/molecular-population-genetics-of-the-northern-elephant-seal-mirounga-angustirostris
#3
Alicia Abadía-Cardoso, Nelson B Freimer, Kristy Deiner, John Carlos Garza
The northern elephant seal, Mirounga angustirostris, was heavily hunted and declared extinct in the 19th century. However, a colony remained on remote Guadalupe Island, Mexico and the species has since repopulated most of its historical distribution. Here, we present a comprehensive evaluation of genetic variation in the species. First, we assess the effect of the demographic bottleneck on microsatellite variability and compare it with that found in other pinnipeds, demonstrating levels of variation similar to that in species that continue to be threatened with extinction...
September 1, 2017: Journal of Heredity
https://www.readbyqxmd.com/read/28820746/no-effects-of-d-cycloserine-enhancement-in-exposure-with-response-prevention-therapy-in-panic-disorder-with-agoraphobia-a-double-blind-randomized-controlled-trial
#4
Mieke Klein Hofmeijer-Sevink, Puck Duits, Marleen M Rijkeboer, Adriaan W Hoogendoorn, Harold J van Megen, Nienke C Vulink, Damiaan A Denys, Marcel A van den Hout, Anton J van Balkom, Danielle C Cath
PURPOSE/BACKGROUND: D-cycloserine (DCS) is a partial N-methyl-D-aspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the effectiveness of adding 125 mg of DCS to exposure therapy (before or directly after the first 6 treatment sessions) in patients with panic disorder with agoraphobia and (2) the effectiveness of DCS augmentation preceding exposure relative to DCS augmentation directly postexposure...
August 18, 2017: Journal of Clinical Psychopharmacology
https://www.readbyqxmd.com/read/28820723/a-lncrna-fine-tunes-the-dynamics-of-a-cell-state-transition-involving-lin28-let-7-and-de-novo-dna-methylation
#5
Meng Amy Li, Paulo P Amaral, Priscilla Cheung, Jan H Bergmann, Masaki Kinoshita, Tüzer Kalkan, Meryem Ralser, Sam Robson, Ferdinand von Meyenn, Maike Paramor, Fengtang Yang, Caifu Chen, Jennifer Nichols, David L Spector, Tony Kouzarides, Lin He, Austin Smith
Execution of pluripotency requires progression from the naïve status represented by mouse embryonic stem cells (ESCs) to a state capacitated for lineage specification. This transition is coordinated at multiple levels. Non-coding RNAs may contribute to this regulatory orchestra. We identified a rodent-specific long non-coding RNA (lncRNA) linc1281, hereafter Ephemeron (Eprn), that modulates the dynamics of exit from naïve pluripotency. Eprn deletion delays the extinction of ESC identity, an effect associated with perduring Nanog expression...
August 18, 2017: ELife
https://www.readbyqxmd.com/read/28820220/real-time-plasmon-spectroscopy-study-of-the-solid-state-oxidation-and-kirkendall-void-formation-in-copper-nanoparticles
#6
Mariano D Susman, Yishai Feldman, Tatyana A Bendikov, Alexander Vaskevich, Israel Rubinstein
Oxidation and corrosion reactions have a major effect on the application of non-noble metals. Kinetic information and simple theoretical models are often insufficient for describing such processes in metals at the nanoscale, particularly in cases involving formation of internal voids (nano Kirkendall effect, NKE) during oxidation. Here we study the kinetics of solid-state oxidation of chemically-grown copper nanoparticles (NPs) by in situ localized surface plasmon resonance (LSPR) spectroscopy during isothermal annealing in the range 110-170 °C...
August 18, 2017: Nanoscale
https://www.readbyqxmd.com/read/28819692/molecular-characterization-of-atypical-antigenic-variants-of-canine-rabies-virus-reveals-its-reintroduction-by-wildlife-vectors-in-southeastern-mexico
#7
Fabiola Garcés-Ayala, Nidia Aréchiga-Ceballos, Joanna M Ortiz-Alcántara, Elizabeth González-Durán, Sandra I Pérez-Agüeros, Alfonso Méndez-Tenorio, Belem Torres-Longoria, Irma López-Martínez, Lucía Hernández-Rivas, José Alberto Díaz-Quiñonez, José Ernesto Ramírez-González
Rabies is an infectious viral disease that is practically always fatal following the onset of clinical signs. In Mexico, the last case of human rabies transmitted by dogs was reported in 2006 and canine rabies has declined significantly due to vaccination campaigns implemented in the country. Here we report on the molecular characterization of six rabies virus strains found in Yucatan and Chiapas, remarkably, four of them showed an atypical reaction pattern when antigenic characterization with a reduced panel of eight monoclonal antibodies was performed...
August 17, 2017: Archives of Virology
https://www.readbyqxmd.com/read/28819056/effects-of-sublethal-doses-of-thiacloprid-and-its-formulation-calypso-%C3%A2-on-the-learning-and-memory-performance-of-honey-bees
#8
Léa Tison, Sophie Holtz, Amy Adeoye, Önder Kalkan, Nina S Irmisch, Randolf Menzel
Learning and memory play a central role in behavior and communication of foraging bees. We already showed that chronic uptake of the neonicotinoid thiacloprid affects the behavior of honey bees in the field. Foraging behavior, homing success, navigation performance, and social communication were impaired. Thiacloprid collected at a feeding site at low doses accumulates in foragers over time. Here we applied a laboratory standard procedure, the proboscis extension response (PER) conditioning, in order to assess which processes, acquisition, memory consolidation and/or memory retrieval were compromised after bees were fed either with thiacloprid or the formulation of thiacloprid named Calypso(®) at 3 different sublethal doses...
August 17, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28817644/cheek-tooth-morphology-and-ancient-mitochondrial-dna-of-late-pleistocene-horses-from-the-western-interior-of-north-america-implications-for-the-taxonomy-of-north-american-late-pleistocene-equus
#9
Christina I Barrón-Ortiz, Antonia T Rodrigues, Jessica M Theodor, Brian P Kooyman, Dongya Y Yang, Camilla F Speller
Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to the end-Pleistocene extinction...
2017: PloS One
https://www.readbyqxmd.com/read/28817193/response-reinforcer-dependency-and-resistance-to-change
#10
Carlos R X Cançado, Josele Abreu-Rodrigues, Raquel Moreira Aló, Flávia Hauck, Adam H Doughty
The effects of the response-reinforcer dependency on resistance to change were studied in three experiments with rats. In Experiment 1, lever pressing produced reinforcers at similar rates after variable interreinforcer intervals in each component of a two-component multiple schedule. Across conditions, in the fixed component, all reinforcers were response-dependent; in the alternative component, the percentage of response-dependent reinforcers was 100, 50 (i.e., 50% response-dependent and 50% response-independent) or 10% (i...
August 17, 2017: Journal of the Experimental Analysis of Behavior
https://www.readbyqxmd.com/read/28816558/effect-of-feedback-from-a-socially-interactive-humanoid-robot-on-reaching-kinematics-in-children-with-and-without-cerebral-palsy-a-pilot-study
#11
Yuping Chen, Sergio Garcia-Vergara, Ayanna M Howard
PURPOSE: To examine whether children with or without cerebral palsy (CP) would follow a humanoid robot's (i.e., Darwin) feedback to move their arm faster when playing virtual reality (VR) games. METHODS: Seven children with mild CP and 10 able-bodied children participated. Real-time reaching was evaluated by playing the Super Pop VR(TM) system, including 2-game baseline, 3-game acquisition, and another 2-game extinction. During acquisition, Darwin provided verbal feedback to direct the child to reach a kinematically defined target goal (i...
August 17, 2017: Developmental Neurorehabilitation
https://www.readbyqxmd.com/read/28814472/neurobiology-of-fear-and-specific-phobias
#12
René Garcia
Fear, which can be expressed innately or after conditioning, is triggered when a danger or a stimulus predicting immediate danger is perceived. Its role is to prepare the body to face this danger. However, dysfunction in fear processing can lead to psychiatric disorders in which fear outweighs the danger or possibility of harm. Although recognized as highly debilitating, pathological fear remains insufficiently treated, indicating the importance of research on fear processing. The neurobiological basis of normal and pathological fear reactions is reviewed in this article...
September 2017: Learning & Memory
https://www.readbyqxmd.com/read/28814465/the-ventromedial-prefrontal-cortex-in-a-model-of-traumatic-stress-fear-inhibition-or-contextual-processing
#13
Zachary T Pennington, Austin S Anderson, Michael S Fanselow
The ventromedial prefrontal cortex (vmPFC) has consistently appeared altered in post-traumatic stress disorder (PTSD). Although the vmPFC is thought to support the extinction of learned fear responses, several findings support a broader role for this structure in the regulation of fear. To further characterize the relationship between vmPFC dysfunction and responses to traumatic stress, we examined the effects of pretraining vmPFC lesions on trauma reactivity and enhanced fear learning in a rodent model of PTSD...
September 2017: Learning & Memory
https://www.readbyqxmd.com/read/28814464/on-the-transition-from-reconsolidation-to-extinction-of-contextual-fear-memories
#14
Lindsey F Cassini, Charlotte R Flavell, Olavo B Amaral, Jonathan L C Lee
Retrieval of an associative memory can lead to different phenomena. Brief reexposure sessions tend to trigger reconsolidation, whereas more extended ones trigger extinction. In appetitive and fear cued Pavlovian memories, an intermediate "null point" period has been observed where neither process seems to be engaged. Here we investigated whether this phenomenon extends to contextual fear memory. Adult rats were subjected to a contextual fear conditioning paradigm, reexposed to the context 2 d later for 3, 5, 10, 20, or 30 min, with immediate injections of MK-801 or saline following reexposure, and tested on the following day...
September 2017: Learning & Memory
https://www.readbyqxmd.com/read/28813640/innate-immune-signaling-in-the-ventral-tegmental-area-contributes-to-drug-primed-reinstatement-of-cocaine-seeking
#15
Kyle T Brown, Sophia C Levis, Casey E O'Neill, Alexis L Northcutt, Timothy J Fabisiak, Linda R Watkins, Ryan K Bachtell
Cocaine addiction is a chronic relapsing disorder characterized by persistent perturbations to an organism's homeostatic processes that result in maladaptive drug seeking. Although considerable attention has been directed at the consequences of neuronal changes following chronic cocaine taking, few studies have examined the role of microglia, the brain's resident immune cells, following chronic cocaine administration. Toll-Like Receptor 4 (TLR4) is a molecular pattern receptor that recognizes pathogens, danger signals, and xenobiotics and induces proinflammatory signaling in the central nervous system...
August 13, 2017: Brain, Behavior, and Immunity
https://www.readbyqxmd.com/read/28813483/muroid-rodent-phylogenetics-900-species-tree-reveals-increasing-diversification-rates
#16
Scott J Steppan, John J Schenk
We combined new sequence data for more than 300 muroid rodent species with our previously published sequences for up to five nuclear and one mitochondrial genes to generate the most widely and densely sampled hypothesis of evolutionary relationships across Muroidea. An exhaustive screening procedure for publically available sequences was implemented to avoid the propagation of taxonomic errors that are common to supermatrix studies. The combined data set of carefully screened sequences derived from all available sequences on GenBank with our new data resulted in a robust maximum likelihood phylogeny for 900 of the approximately 1,620 muroids...
2017: PloS One
https://www.readbyqxmd.com/read/28812706/a-decade-of-insights-into-grassland-ecosystem-responses-to-global-environmental-change
#17
REVIEW
Elizabeth T Borer, James B Grace, W Stanley Harpole, Andrew S MacDougall, Eric W Seabloom
Earth's biodiversity and carbon uptake by plants, or primary productivity, are intricately interlinked, underlie many essential ecosystem processes, and depend on the interplay among environmental factors, many of which are being changed by human activities. While ecological theory generalizes across taxa and environments, most empirical tests of factors controlling diversity and productivity have been observational, single-site experiments, or meta-analyses, limiting our understanding of variation among site-level responses and tests of general mechanisms...
April 20, 2017: Nature ecology & evolution
https://www.readbyqxmd.com/read/28812704/biological-extinction-at-the-vatican
#18
Stuart Pimm
No abstract text is available yet for this article.
April 10, 2017: Nature ecology & evolution
https://www.readbyqxmd.com/read/28812696/skeletal-trauma-reflects-hunting-behaviour-in-extinct-sabre-tooth-cats-and-dire-wolves
#19
Caitlin Brown, Mairin Balisi, Christopher A Shaw, Blaire Van Valkenburgh
Skeletal-injury frequency and distribution are likely to reflect hunting behaviour in predatory vertebrates and might therefore differ between species with distinct hunting modes. Two Pleistocene predators from the Rancho La Brea asphalt seeps, the sabre-tooth cat, Smilodon fatalis, and dire wolf, Canis dirus, represent ambush and pursuit predators, respectively. On the basis of a collection of over 1,900 pathological elements, the frequency of traumatic injury across skeletal elements in these two species was calculated...
April 10, 2017: Nature ecology & evolution
https://www.readbyqxmd.com/read/28812683/megafaunal-isotopes-reveal-role-of-increased-moisture-on-rangeland-during-late-pleistocene-extinctions
#20
M Timothy Rabanus-Wallace, Matthew J Wooller, Grant D Zazula, Elen Shute, A Hope Jahren, Pavel Kosintsev, James A Burns, James Breen, Bastien Llamas, Alan Cooper
The role of environmental change in the late Pleistocene megafaunal extinctions remains a key question, owing in part to uncertainty about landscape changes at continental scales. We investigated the influence of environmental changes on megaherbivores using bone collagen nitrogen isotopes (n = 684, 63 new) as a proxy for moisture levels in the rangelands that sustained late Pleistocene grazers. An increase in landscape moisture in Europe, Siberia and the Americas during the Last Glacial-Interglacial Transition (LGIT; ~25-10 kyr bp) directly affected megaherbivore ecology on four continents, and was associated with a key period of population decline and extinction...
April 18, 2017: Nature ecology & evolution
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