bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorylation of axonemal 21 kDa and 26 kDa proteins modulates activation of sperm motility in the ascidian,Ciona intestinalis
Authors: Nomura Mamoru , Inaba Kazuo , Morisawa Masaaki
Published: July 2018

Protein phosphorylation is highly coupled with sperm motility activation in several animal species. The micro-tubule based flagellar motor protein, dynein, is a candidate for a phosphoprotein related to sperm activation in many animal species (Morisawa & Hayashi, 1985; Hayashiet al., 1987; Dey & Brokaw, 1991; Stephens & Prior, 1992; Inabaet al., 1998, 1999). Sperm motility of the ascidiansCiona intestinalisandC. savignyiis activated by a factor derived from unfertilised eggs named sperm activating and attracting factor (SAAF). SAAF elevates the intracellular cyclic AMP (cAMP) level by a mechanism dependent on membrane hyperpolarisation and extracellular Ca2+(Yoshidaet al., 1994; Izumiet al., 1999). Experiments using demembranatedCionasperm showed that cAMP is required prior to ATP for the activation of axonemal movement (Opreska & Brokaw, 1983; Morisawaet al., 1984; Brokaw, 1985; Dey & Brokaw, 1991; Chaudhryet al., 1995) and that many sperm flagellar proteins including dynein light chain are phosphorylated during incubation of demembranated sperm with ATP and cAMP (Dey & Brokaw, 1991). However, there is no evidence of which proteins are phosphorylated during the SAAF-dependent activation ofCionasperm motility.
Fertilisation in fish: a cortical alveolar lectin and its potential role in the block to polyspermy
Authors: Yasumasu Shigeki , Wardrip Nathan J. , Zenner Bruce D. , Lee Young M. , Smith Alan J. , Hedrick Jerry L.
Published: July 2018

An animal egg such as amphibian, mammalian or sea urchin egg receives only a single sperm at fertilisation. After binding of the first sperm, the egg is prevented from allowing the entry of additional sperm. In fact, polyspermy results in aborted development of the zygote. It has been generally accepted that a molecule(s) released from cortical granules participates in the block to polyspermy. As one such molecule, a cortical granule lectin has been isolated from unfertilised Xenopus eggs (Xenopus cortical granule lectin; XCGL). XCGL is released into the perivitelline space after fertilisation, and forms a complex with J1 jelly molecules to form an F layer, resulting in a block to additional sperm penetration.

A lectin molecule has also been purified from the eggs of several species of fish. The fish egg lectin is located in the cortical alveoli and is released from them after fertilisation. However, its biological function is unclear. We isolated cortical alveolar lectin from unfertilised eggs of Chinook salmon through affinity column chromatography (salmon egg lectin; SEL). The lectin activity was estimated by haemagglutination. The activity of the purified SEL was most strongly inhibited by L-rhamnose and D-galactose, but not by EDTA. Further analysis by C4 reverse-phase column chromatography using HPLC revealed that the lectin was composed of three subunit proteins: 24K, 26Ka and 26Kb proteins. In addition, we cloned cDNAs for them by RT-PCR. The deduced amino acid sequence of the 26Ka protein was homologous with that of the 26Kb protein (identity, 96.4%). Identities of the 24K with the 26Ka and the 26Kb proteins were 55.9% and 66.7%, respectively. A database search revealed that a lectin molecule similar to the SEL had been identified in Anthocidaris crassispina egg (sea urchin egg lectin; SUEL). The SUEL is composed of 105 amino acids, and is similar to both amino-terminal and carboxyl-terminal halves of the SELs. Thus, the SEL molecule is composed of two repeats of such SUEL-like domains, suggesting that the SEL gene was produced by gene duplication.
Influence of Crop Competition and Harvest Weed Seed Control on Rigid Ryegrass (Lolium rigidum) Seed Retention Height in Wheat Crop Canopies
Authors: Walsh Michael J. , Broster John C. , Aves Charlotte , Powles Stephen B.
Published: July 2018

Harvest weed seed control (HWSC) is an Australian innovation, developed to target high proportions of weed seed retained at crop maturity by many major weed species. There is the potential, however, that a reduction in the average height of retained seed is an adaptation to the long-term use of HWSC practices. With the aim of examining the distribution of rigid ryegrass (Lolium rigidumGaudin) seed through crop canopies, a survey of Australian wheat (Triticum aestivumL.) fields was conducted at crop maturity. Nine sites with medium to long-term HWSC use were specifically included to examine the influence of HWSC use on seed retention height. During the 2013 wheat harvest,L. rigidumand wheat plant samples were collected at five heights downward through the crop canopy (40, 30, 20, 10, and 0 cm above ground level) in 71 wheat fields. Increased crop competition resulted in higher proportions ofL. rigidumseed in the upper crop canopy (>40 cm). The increase in plant height is likely a shade-intolerance response ofL. rigidumplants attempting to capture more light. This plant attribute creates the opportunity to use crop competition to improve HWSC efficacy by increasing the average height of seed retention. Crop competition can, therefore, have a double impact by reducing overallL. rigidumseed production and increasing seed retention height. Examining the distribution of wheat biomass andL. rigidumseed through the crop canopy, we determined that reducing harvest height for HWSC considerably increased the collection ofL. rigidumseed (25%) but to a lesser extent wheat crop biomass (14%). Comparison of + and − HWSC use at nine locations found no evidence of adaptation to this form of weed control following 5 to 10 yr of use. Although the potential for resistance to HWSC remains, these results indicate that this will not readily occur in the field.
Ein Plädoyer für eine verstärkte Berücksichtigung der Verhaltenskomponente in der sportpsychologischen Emotionsforschung
Authors: Fritsch Julian , Elbe Anne-Marie , Hatzigeorgiadis Antonis
Published: July 2018

Zusammenfassung. Bei der Erforschung des Zusammenhangs zwischen Emotionen und sportlicher Leistung wurde bisher fast ausschließlich das subjektive Erleben der Sporttreibenden untersucht. Dabei war es gängige Praxis Emotionen mit Fragebögen oder Interviews prospektiv bzw. retrospektiv zu erfassen. Ferner wurden in Experimenten Emotionen erzeugt, um anschließend deren Einfluss auf zum Beispiel die sportliche Leistung zu messen. Da Emotionen jedoch auch anhand von Veränderungen im Gesicht, der Gestik, der Körperhaltung oder der Stimme beobachtbar sind, wird in diesem Beitrag dafür argumentiert, zukünftig auch die Verhaltenskomponente von Emotionen verstärkt miteinzubeziehen. Bei der systematischen Verhaltensbeobachtung können Emotionen „online“ in ihrem natürlichen Kontext erfasst werden. Darüber hinaus wird darauf eingegangen, wie Veränderungen im beobachtbaren Verhalten leistungsrelevante Konsequenzen sowohl für die Person selbst als auch für andere Personen (z.B. Gegner oder Gegnerin) haben können, die nur sehr bedingt durch die Erlebniskomponente einer Emotion erklärt werden können. Abschließend werden mögliche Herausforderungen, die mit der Erforschung der Verhaltenskomponente von Emotionen im Zusammenhang stehen, diskutiert.
MARSIS Observations of Field‐Aligned Irregularities and Ducted Radio Propagation in the Martian Ionosphere
Authors: Andrews D. J. , Opgenoorth H. J. , Leyser T. B. , Buchert S. , Edberg N. J. T. , Morgan D. D. , Gurnett D. A. , Kopf A. J. , Fallows K. , Withers P.
Published: July 2018

Knowledge of Mars's ionosphere has been significantly advanced in recent years by observations from Mars Express and lately Mars Atmosphere and Volatile EvolutioN. A topic of particular interest are the interactions between the planet's ionospheric plasma and its highly structured crustal magnetic fields and how these lead to the redistribution of plasma and affect the propagation of radio waves in the system. In this paper, we elucidate a possible relationship between two anomalous radar signatures previously reported in observations from the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on Mars Express. Relatively uncommon observations of localized, extreme increases in the ionospheric peak density in regions of radial (cusp‐like) magnetic fields and spread echo radar signatures are shown to be coincident with ducting of the same radar pulses at higher altitudes on the same field lines. We suggest that these two observations are both caused by a high electric field (perpendicular to B) having distinctly different effects in two altitude regimes. At lower altitudes, where ions are demagnetized and electrons magnetized, and recombination dominantes, a high electric field causes irregularities, plasma turbulence, electron heating, slower recombination, and ultimately enhanced plasma densities. However, at higher altitudes, where both ions and electrons are magnetized and atomic oxygen ions cannot recombine directly, the high electric field instead causes frictional heating, a faster production of molecular ions by charge exchange, and so a density decrease. The latter enables ducting of radar pulses on closed field lines, in an analogous fashion to interhemispheric ducting in the Earth's ionosphere.
Connectivity of Pulley Ridge With Remote Locations as Inferred From Satellite‐Tracked Drifter Trajectories
Authors: Olascoaga M. J. , Miron P. , Paris C. , Pérez‐Brunius P. , Pérez‐Portela R. , Smith R. H. , Vaz A.
Published: July 2018

Using historical (1994–2017) satellite‐tracked surface drifter trajectory data, we conduct a probabilistic Lagrangian circulation study which sheds light on the connectivity of Pulley Ridge with other locations in the Gulf of Mexico and adjacent areas. The analysis reveals that Pulley Ridge is connected with the North Atlantic, the Caribbean Sea, and most of the Gulf of Mexico. Preferred connecting pathways are identified and arrival times to potential reef sites computed. The study demonstrates the importance of Pulley Ridge as a source for neighboring regions like the Dry Tortugasa, the Florida Keys, Campeche Bank, and the east Florida coast as well as a self‐recruitment area for species with short competence time. The study further suggests that the reefs in the Caribbean Sea, the Dry Tortugas, the western Florida Keys, and the West Florida Shelf can act as sources for Pulley Ridge, indicating the importance of Pulley Ridge as a central refugium for species in the Gulf of Mexico.
Internal Structure of a Self‐Accelerating Turbidity Current
Authors: Sequeiros Octavio E. , Mosquera Rodrigo , Pedocchi Francisco
Published: July 2018

A self‐accelerating current is a particle‐driven gravity flow moving on a sloping bed whose velocity surges in the downstream direction as a result of increasing suspended sediment concentration entrained from the bed. This concept although introduced decades ago has proved elusive to be measured, but it is critical to explain the increasing evidence that turbidity currents are arguably the leading process for conveying sediments down the continental slope and beyond. It implies that both flow velocity and suspended concentration increase due to a feedback loop up to the point where some external condition restrains the process. The higher the velocity is, the larger the grain size and sediment concentration that can be kept in suspension; conversely, the denser the flow is, the faster it moves downslope. This work documents laboratory experiments of plunging (hyperpycnal) turbidity currents composed of noncohesive particles ranging from 20 to 200 μm with a specific density of 1.5. The experiments were performed in a 15‐m‐long flume with a bottom slope of 5%. Self‐acceleration of the front and body of the flow was achieved during the experiments and documented using both video recordings and ultrasonic velocity profilers (UVP). The UVP backscatter signal was calibrated with physical samples and used for estimating suspended sediment concentration profiles. The plunging mechanism played a lead role during the experiments by purging the flow from suspended material beyond its capacity and from coarse grains beyond its competence. Self‐acceleration was observed in some of the performed tests. Acceleration of the current front was clearly recorded with the video cameras, while the UVP recordings captured acceleration within the current body along the flume. The measured depth‐averaged velocity in the current body was higher than the velocity of the current front, thus indicating an internal circulation pattern that shapes the current front and head. Our experiments indicate that a supercritical flow regime is a necessary but not a sufficient condition for the occurrence of a self‐accelerating turbidity current. Whether the current self‐accelerates or not on a certain sloping bottom seems to be determined by flow discharge, concentration, size of suspended material, and availability of entrainable sediment at the bed. Deposits formed during the experiments showed that turbidites generated by self‐accelerating currents presented both less pronounced thinning and fining downstream rates than those generated by decelerating or depositional currents. This signature may be used in the sedimentary record to discern the turbidite forming flow.
Real‐Time Sensing of Precipitable Water Vapor From BeiDou Observations: Hong Kong and CMONOC Networks
Authors: Li Xingxing , Tan Han , Li Xin , Dick Galina , Wickert Jens , Schuh Harald
Published: July 2018

The development of BeiDou Navigation Satellite System (BDS) provides opportunities for real‐time retrieval of precipitable water vapor (PWV), which is expected to significantly contribute to time‐critical meteorological applications. In this study, observations from 17 stations of the Hong Kong Continuously Operating Reference Stations and 15 stations of the Crustal Movement Observation Network of China (CMONOC) are used to retrieve PWV based on the real‐time precise point positioning ambiguity resolution approach. Real‐time PWV products, retrieved from BDS observations of both summer (day of year 183–192) and winter (day of year 024–033) periods, are analyzed and validated using postprocessed Global Positioning System products. The results show that the real‐time BDS PWV series agree well with the Global Positioning System PWV series. Root‐mean‐square values for the Hong Kong Continuously Operating Reference Stations and CMONOC stations are 2.0–3.5 and 2.5–4.0 mm, respectively. In addition, short initialization time, strong reliability, and good distribution could be achieved by applying the fixed solution instead of the float solution. With the gradual completion of BDS constellation, the BDS can independently contribute to real‐time sensing of PWV and potentially contribute to time‐critical meteorological applications.
Methane Efflux Measured by Eddy Covariance in Alaskan Upland Tundra Undergoing Permafrost Degradation
Authors: Taylor M. A. , Celis G. , Ledman J. D. , Bracho R. , Schuur E. A. G.
Published: July 2018

Greenhouse gas emissions from thawing permafrost in arctic ecosystems may amplify global warming, yet estimates of the rate of carbon release, and the proportion of carbon released as methane (CH4) or carbon dioxide (CO2), have a high degree of uncertainty. There are many areas where no measurements exist, and few year‐round or long‐term records. Existing year‐round eddy covariance measurements of arctic CH4fluxes suggest that nongrowing season emissions make up a significant proportion of tundra systems emissions on an annual basis. Here we present continuous CH4flux measurements made at Eight Mile Lake, an upland tundra ecosystem undergoing permafrost degradation in Interior Alaska. We found net CH4emissions throughout the year (1.2 ∓ 0.011 g C‐CH4m2/yr) that made up 61% of total radiative forcing from annual C emissions (CO2and CH4; 32.3 g C m2/yr) when taking into account the greenhouse warming potential of CH4relative to CO2. Nongrowing season emissions accounted for 50% of the annual CH4budget, characterized by large pulse emissions. These were related to abrupt increases in air and shallow soil temperatures rather than consistent emissions during the zero curtain—a period of the fall/early winter season when subsurface soil temperatures remain near the 0 °C freezing point. Weekly growing season CH4emissions in 2016 and 2017 were significantly related with thaw depth, and the magnitude of CH4emissions between these seasons was proportional to the rate of active layer thaw throughout the season.
The Solar Particle Event on 10–13 September 2017: Spectral Reconstruction and Calculation of the Radiation Exposure in Aviation and Space
Authors: Matthiä Daniel , Meier Matthias M. , Berger Thomas
Published: July 2018

The solar energetic particle event on 10 September 2017 and on the following days was the strongest event in recent years. It was recorded as ground level enhancement 72 by neutron monitor stations on Earth and measured by a number of instruments in space. One aspect of such a space weather event is the potentially increased radiation exposure in aviation and space. Numerical simulations can help estimate the elevated dose rates during such an event; a critical aspect in these simulations is the description of the primary particle spectrum. In this work, we present 1‐hr averaged proton spectra during the event derived from Geostationary Operational Environmental Satellite measurements and described by two different analytic functions. The derived proton spectra are used to calculate the radiation exposure in aviation and different space scenarios: low‐Earth orbit, interplanetary space, and Mars surface, and the results are discussed in the context of available experimental data. While the results indicate that in most of these scenarios in aviation and space the event was of little significance compared to the total exposure from galactic cosmic radiation, the skin dose in a lightly shielded environment in interplanetary space may have reached about 30% to 60% of the NASA 30‐day dose limit.
Gain through losses in nonlinear optics
Authors: Perego Auro M. , Turitsyn Sergei K. , Staliunas Kestutis
Published: July 2018

Instabilities of uniform states are ubiquitous processes occurring in a variety of spatially extended nonlinear systems. These instabilities are at the heart of symmetry breaking, condensate dynamics, self-organisation, pattern formation, and noise amplification across diverse disciplines, including physics, chemistry, engineering, and biology. In nonlinear optics, modulation instabilities are generally linked to the so-called parametric amplification process, which occurs when certain phase-matching or quasi-phase-matching conditions are satisfied.

In the present review article, we summarise the principle results on modulation instabilities and parametric amplification in nonlinear optics, with special emphasis on optical fibres. We then review state-of-the-art research about a peculiar class of modulation instabilities (MIs) and signal amplification processes induced by dissipation in nonlinear optical systems. Losses applied to certain parts of the spectrum counterintuitively lead to the exponential growth of the damped mode themselves, causing gain through losses. We discuss the concept of imaging of losses into gain, showing how to map a given spectral loss profile into a gain spectrum. We demonstrate with concrete examples that dissipation-induced MI, apart from being of fundamental theoretical interest, may pave the way towards the design of a new class of tuneable fibre-based optical amplifiers, optical parametric oscillators, frequency comb sources, and pulsed lasers.
Shared endo-phenotypes of default mode dysfunction in attention deficit/hyperactivity disorder and autism spectrum disorder
Authors: Kernbach Julius M. , Satterthwaite Theodore D. , Bassett Danielle S. , Smallwood Jonathan , Margulies Daniel , Krall Sarah , Shaw Philip , Varoquaux Gaël , Thirion Bertrand , Konrad Kerstin , Bzdok Danilo
Published: July 2018

Categorical diagnoses from the Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) manuals are increasingly found to be incongruent with emerging neuroscientific evidence that points towards shared neurobiological dysfunction underlying attention deficit/hyperactivity disorder and autism spectrum disorder. Using resting-state functional magnetic resonance imaging data, functional connectivity of the default mode network, the dorsal attention and salience network was studied in 1305 typically developing and diagnosed participants. A transdiagnostic hierarchical Bayesian modeling framework combining Indian Buffet Processes and Latent Dirichlet Allocation was proposed to address the urgent need for objective brain-derived measures that can acknowledge shared brain network dysfunction in both disorders. We identified three main variation factors characterized by distinct coupling patterns of the temporoparietal cortices in the default mode network with the dorsal attention and salience network. The brain-derived factors were demonstrated to effectively capture the underlying neural dysfunction shared in both disorders more accurately, and to enable more reliable diagnoses of neurobiological dysfunction. The brain-derived phenotypes alone allowed for a classification accuracy reflecting an underlying neuropathology of 67.33% (+/−3.07) in new individuals, which significantly outperformed the 46.73% (+/−3.97) accuracy of categorical diagnoses. Our results provide initial evidence that shared neural dysfunction in ADHD and ASD can be derived from conventional brain recordings in a data-led fashion. Our work is encouraging to pursue a translational endeavor to find and further study brain-derived phenotypes, which could potentially be used to improve clinical decision-making and optimize treatment in the future.
Oxidized phospholipids are ligands for LRP6
Authors: Wang Lei , Chai Yu , Li Changjun , Liu Haiyun , Su Weiping , Liu Xiaonan , Yu Bing , Lei Weiqi , Yu Bin , Crane Janet L. , Cao Xu , Wan Mei
Published: July 2018

Low-density lipoprotein receptor–related protein 6 (LRP6) is a co-receptor for Wnt signaling and can be recruited by multiple growth factors/hormones to their receptors facilitating intracellular signaling activation. The ligands that bind directly to LRP6 have not been identified. Here, we report that bioactive oxidized phospholipids (oxPLs) are native ligands of LRP6, but not the closely related LRP5. oxPLs are products of lipid oxidation involving in pathological conditions such as hyperlipidemia, atherosclerosis, and inflammation. We found that cell surface LRP6 in bone marrow mesenchymal stromal cells (MSCs) decreased rapidly in response to increased oxPLs in marrow microenvironment. LRP6 directly bound and mediated the uptake of oxPLs by MSCs. oxPL-LRP6 binding induced LRP6 endocytosis through a clathrin-mediated pathway, decreasing responses of MSCs to osteogenic factors and diminishing osteoblast differentiation ability. Thus, LRP6 functions as a receptor and molecular target of oxPLs for their adverse effect on MSCs, revealing a potential mechanism underlying atherosclerosis-associated bone loss.
Contribution of autophagy to ocular hypertension and neurodegeneration in the DBA/2J spontaneous glaucoma mouse model
Authors: Hirt Joshua , Porter Kris , Dixon Angela , McKinnon Stuart , Liton Paloma B.
Published: July 2018

Glaucoma is a progressive optic neuropathy characterized by axonal degeneration and retinal ganglion cells loss. Several factors have been postulated to play a role in glaucoma, elevated intraocular pressure (IOP) being the best well-known causative factor. The mechanisms leading to ocular hypertension and glaucoma are still not fully understood. An increasing number of evidence indicates a role of autophagy in the pathophysiological process of ocular hypertension and glaucoma. However, while all of the studies agree that autophagy is induced in RGCs in response to injury, autophagy was found to either protect or promote cell death depending on the experimental model used. In order to gain more insight into both, the role of autophagy in the pathogenesis of glaucoma and the effect of chronic IOP elevation in the autophagy pathway, we have investigated here for the first time autophagy in the iridocorneal angle region, retinal ganglion cell bodies, and ON axons in the spontaneous ocular hypertensive DBA/2J mouse glaucoma model and in the transgenic DBA/2J::GFP-LC3 mice, generated in our laboratory. Our results indicate decreased autophagic flux in the outflow pathway cells in the DBA/2J mice, characterized by increased levels of LC3-II and p62 together with a decrease in the lysosomal marker LAMP1, evaluated by western blot and immunofluorescence. Elevated presence of autophagic vacuoles in the DBA/2J and, in particular, in the DBA/2J::GFP-LC3 mice was also observed. Expression of the GFP-LC3 transgene was associated to higher cumulative IOP in the DBA/2J background. In addition to higher elevation in IOP, DBA/2J::GFP-LC3 were characterized by further RGCs and exacerbated axonal degeneration compared to DBA/2J. This was accompanied by the notable high presence of autophagic figures within degenerating axons. These results strongly suggest overactivation of autophagy as a potential cellular mechanism leading to ON degeneration in the chronic hypertensive DBA/2J mice.
Cellular and molecular responses to acute cocaine treatment in neuronal-like N2a cells: potential mechanism for its resistance in cell death
Authors: Badisa Ramesh B. , Wi Sungsool , Jones Zachary , Mazzio Elizabeth , Zhou Yi , Rosenberg Jens T. , Latinwo Lekan M. , Grant Samuel C. , Goodman Carl B.
Published: July 2018

Cocaine is a highly abused drug that causes psychiatric and neurological problems. Its entry into neurons could alter cell-biochemistry and contribute in the manifestation of early pathological symptoms. We have previously shown the acute cocaine effects in rat C6 astroglia-like cells and found that these cells were highly sensitive to cocaine in terms of manifesting certain pathologies known to underlie psychological disorders. The present study was aimed to discern acute cocaine effects on the early onset of various changes in Neuro-2a (N2a) cells. Whole-cell patch-clamp recording of differentiated cells displayed the functional voltage-gated Na+ and K+ channels, which demonstrated the neuronal characteristics of the cells. Treatment of these cells with acute cocaine (1 h) at in vivo (nM to μM) and in vitro (mM) concentrations revealed that the cells remained almost 100% viable. Cocaine administration at 6.25 μM or 4 mM doses significantly reduced the inward currents but had no significant effect on outward currents, indicating the Na+ channel-blocking activity of cocaine. While no morphological change was observed at in vivo doses, treatment at in vitro doses altered the morphology, damaged the neurites, and induced cytoplasmic vacuoles; furthermore, general mitochondrial activity and membrane potential were significantly decreased. Mitochondrial dysfunction enabled the cells switch to anaerobic glycolysis, evidenced by dose-dependent increases in lactate and H2S, resulting unaltered ATP level in the cells. Further investigation on the mechanism of action unfolded that the cell’s resistance to cocaine was through the activation of nuclear factor E2-related factor-2 (Nrf-2) gene and subsequent increase of antioxidants (glutathione [GSH], catalase and GSH peroxidase [GPx]). The data clearly indicate that the cells employed a detoxifying strategy against cocaine. On a broader perspective, we envision that extrapolating the knowledge of neuronal resistance to central nervous system (CNS) diseases could delay their onset or progression.
Programmed loading and rapid purification of engineered bacterial microcompartment shells
Authors: Hagen Andrew , Sutter Markus , Sloan Nancy , Kerfeld Cheryl A.
Published: July 2018

Bacterial microcompartments (BMCs) are selectively permeable proteinaceous organelles which encapsulate segments of metabolic pathways across bacterial phyla. They consist of an enzymatic core surrounded by a protein shell composed of multiple distinct proteins. Despite great potential in varied biotechnological applications, engineering efforts have been stymied by difficulties in their isolation and characterization and a dearth of robust methods for programming cores and shell permeability. We address these challenges by functionalizing shell proteins with affinity handles, enabling facile complementation-based affinity purification (CAP) and specific cargo docking sites for efficient encapsulation via covalent-linkage (EnCo). These shell functionalizations extend our knowledge of BMC architectural principles and enable the development of minimal shell systems of precisely defined structure and composition. The generalizability of CAP and EnCo will enable their application to functionally diverse microcompartment systems to facilitate both characterization of natural functions and the development of bespoke shells for selectively compartmentalizing proteins.
Unraveling substituent effects on the glass transition temperatures of biorenewable polyesters
Authors: Yu Xiaopeng , Jia Junteng , Xu Shu , Lao Ka Un , Sanford Maria J. , Ramakrishnan Ramesh K. , Nazarenko Sergei I. , Hoye Thomas R. , Coates Geoffrey W. , DiStasio Robert A.
Published: July 2018

Converting biomass-based feedstocks into polymers not only reduces our reliance on fossil fuels, but also furnishes multiple opportunities to design biorenewable polymers with targeted properties and functionalities. Here we report a series of high glass transition temperature (Tg up to 184 °C) polyesters derived from sugar-based furan derivatives as well as a joint experimental and theoretical study of substituent effects on their thermal properties. Surprisingly, we find that polymers with moderate steric hindrance exhibit the highest Tg values. Through a detailed Ramachandran-type analysis of the rotational flexibility of the polymer backbone, we find that additional steric hindrance does not necessarily increase chain stiffness in these polyesters. We attribute this interesting structure-property relationship to a complex interplay between methyl-induced steric strain and the concerted rotations along the polymer backbone. We believe that our findings provide key insight into the relationship between structure and thermal properties across a range of synthetic polymers.
Atomic-level insight into super-efficient electrocatalytic oxygen evolution on iron and vanadium co-doped nickel (oxy)hydroxide
Authors: Jiang Jian , Sun Fanfei , Zhou Si , Hu Wei , Zhang Hao , Dong Jinchao , Jiang Zheng , Zhao Jijun , Li Jianfeng , Yan Wensheng , Wang Mei
Published: July 2018

It is of great importance to understand the origin of high oxygen-evolving activity of state-of-the-art multimetal oxides/(oxy)hydroxides at atomic level. Herein we report an evident improvement of oxygen evolution reaction activity via incorporating iron and vanadium into nickel hydroxide lattices. X-ray photoelectron/absorption spectroscopies reveal the synergistic interaction between iron/vanadium dopants and nickel in the host matrix, which subtly modulates local coordination environments and electronic structures of the iron/vanadium/nickel cations. Further, in-situ X-ray absorption spectroscopic analyses manifest contraction of metal–oxygen bond lengths in the activated catalyst, with a short vanadium–oxygen bond distance. Density functional theory calculations indicate that the vanadium site of the iron/vanadium co-doped nickel (oxy)hydroxide gives near-optimal binding energies of oxygen evolution reaction intermediates and has lower overpotential compared with nickel and iron sites. These findings suggest that the doped vanadium with distorted geometric and disturbed electronic structures makes crucial contribution to high activity of the trimetallic catalyst.
Is there a role for immunotherapy in HER2-positive breast cancer?
Authors: Holgado Esther , Perez-Garcia Jose , Gion Maria , Cortes Javier
Published: July 2018

Although the prognosis and prediction of therapeutic benefit for breast cancer patients overexpressing the human epidermal growth factor receptor 2 (HER2) have dramatically changed with the administration of anti-HER2-targeted therapies, HER2-positive metastatic breast cancer is still an incurable disease. Thus, new and better therapeutic options are urgently needed. Among them, are the agents stemming from the field of immunology that have been the focus of impressive scientific progress and new therapeutic opportunities seem to emerge “every day” in a variety of tumor types.
Macroscopically Anisotropic Structures Produced by Light-induced Solvothermal Assembly of Porphyrin Dimers
Authors: Yamamoto Yasuyuki , Nishimura Yushi , Tokonami Shiho , Fukui Norihito , Tanaka Takayuki , Osuka Atsuhiro , Yorimitsu Hideki , Iida Takuya
Published: July 2018

Porphyrin-based molecules play an important role in natural biological systems such as photosynthetic antennae and haemoglobin. Recent organic chemistry provides artificial porphyrin-based molecules having unique electronic and optical properties, which leads to wide applications in material science. Here, we successfully produced many macroscopically anisotropic structures consisting of porphyrin dimers by light-induced solvothermal assembly with smooth evaporation in a confined volatile organic solvent. Light-induced fluid flow around a bubble on a gold nanofilm generated a sub-millimetre radial assembly of the tens-micrometre-sized petal-like structures. The optical properties of the petal-like structures depend on the relative angle between their growth direction and light polarisation, as confirmed by UV-visible extinction and the Raman scattering spectroscopy analyses, being dramatically different from those of structures obtained by natural drying. Thus, our findings pave the way to the production of structures and polycrystals with unique characteristics from various organic molecules.
Early harvesting improves seed vigour of hybrid rice seeds
Authors: Wang Xiaomin , Zheng Huabin , Tang Qiyuan
Published: July 2018

Maturity stage in harvesting time greatly affects seed vigour. This work aimed to scientific harvesting time of hybrid rice for being high vigour with high & stable seed yield. Field experiments of different harvesting time were conducted in 2013–2014, and germination percentage (GP), vigour index (VI), seed moisture content and 1000-grain weight was determined. Both GP and VI progressively increased to peaks and then began to decline with harvesting time delayed, and the regression coefficients of varieties were ranged from 0.7214 to 0.9066. In addition, difference values between tangent points (ΔX) of GP were higher than that of VI according to the quadratic functions. Based on seed vigour through the divided range from 75% to 125% of peak value, optimum harvesting time of IIY-416, JY-167, Yliangyou-1 (YLY-1) ranged from 17 to 27, 15 to 23 and 17 to 23 days after the completion of artificial pollination (DACAP), respectively. Moreover, when seedlots harvested from 17 to 23 DACAP, no significant difference was found on 1000-grain weight and the seed moisture content was kept relatively low (19–25%). Therefore, it can be concluded that hybrid rice seed can be earlier-harvest based on seed vigour, and 17 to 23 DACAP can be recommended as optimum harvesting time during hybrid rice seed production.
PAS Kinase deficiency alters the glucokinase function and hepatic metabolism
Authors: Pérez-García A. , Dongil P. , Hurtado-Carneiro V. , Blazquez E. , Sanz C. , Alvarez E.
Published: July 2018

The liver controls metabolic homeostasis in response to fasting and refeeding periods. Glucokinase (GCK) adjusts hepatic glucose phosphorylation to blood glucose levels, acting as a glucose sensor. Our objective was to determine whether PAS kinase (PASK), a nutrient sensor, could be affecting the expression or activity of liver GCK and the response to fasting and refeeding states of key hepatic metabolic pathways. PASK-deficient mice have impaired insulin signaling (AKT overactivation). Furthermore, PASK deficiency modified the expression of several transcription factors involved in the adjustment to fasting and refeeding. Foxo1 decreased under fasting conditions, while Ppara and Pparg were overexpressed in PASK-deficient mice. However, PEPCK protein levels were similar or higher, while the expression of Cpt1a decreased in PASK-deficient mice. By contrast, Lxra and Chrebp were overexpressed after refeeding, while the expression of Acc and Fas decreased in PASK-deficient mice. Likewise, with a decreased expression of Gck and increased nuclear location of the complex GCK-GCKR, GCK activity decreased in PASK-deficient mice. Therefore, PASK regulated some of the genes and proteins responsible for glucose sensing, such as glucokinase, and for insulin signalling, affecting glucose and lipid metabolism and consequently certain critical hepatic functions.
Author Correction: Mutant p53 stimulates cell invasion through an interaction with Rad21 in human ovarian cancer cells
Authors: Ahn Ji-Hye , Kim Tae Jin , Lee Jae Ho , Choi Jung-Hye
Published: July 2018

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Epigenetic and transcriptional dysregulation of VWA2 associated with a MYC-driven oncogenic program in colorectal cancer
Authors: González Beatriz , Fece de la Cruz Ferran , Samuelsson Johanna Kristina , Alibés Andreu , Alonso Sergio
Published: July 2018

VWA2 encodes AMACO, a secreted protein up-regulated in most colorectal carcinomas (CRC), constituting a promising biomarker. The mechanism responsible for its aberrant up-regulation has not been previously described. In this work, we analyzed VWA2 DNA methylation in over 400 primary CRCs. No epigenetic alterations were found in its promoter-associated CpG island. However, the region located downstream of the transcriptional start site was hypomethylated in most CRCs. ChIP-Seq revealed increased levels of the active mark H3K4me3 and reduction of the repressive mark H3K27me3. In contrast, several CRC cell lines exhibited hypermethylation of VWA2. 5-AZA-2-deoxycitidine treatment led to transcriptional activation of VWA2, supporting a functional link between DNA methylation and transcription. VWA2 expression in primary CRCs correlated with that of Myc and Myc-target genes. Transcriptional up-regulation of VWA2 is extremely frequent (78%) and strong (average fold change >15) in CRC, but not in other types of cancer. VWA2 undergoes hypomethylation in the majority of CRCs. This alteration could partly underlie the previously reported over-expression of AMACO. Co-expression profiling suggests that VWA2 might be a constituent of a larger oncogenic transcriptional program regulated by c-Myc. Up-regulation of VWA2 is virtually exclusive of CRC, reinforcing its potential as a specific biomarker.
In-plane direct current probing for spin orbit torque-driven effective fields in perpendicularly magnetized heavy metal/ferromagnet/oxide frames
Authors: Yang Seungmo , Choi Jinhyung , Shin Junghoon , Yoon Kapsoo , Yang Jungyup , Hong JinPyo
Published: July 2018

Electrical manipulation of magnetization states has been the subject of intense focus as it is a long-standing goal in the emerging field of spintronics. In particular, torque generated by an in-plane current with a strong spin-orbit interaction shows promise for control of the adjacent ferromagnetic state in heavy-metal/ferromagnet/oxide frames. Thus, the ability to unlock precise spin orbit torque-driven effective fields represents one of the key approaches in this work. Here, we address an in-plane direct current measurement approach as a generic alternative tool to identify spin orbit torque-driven effective fields in a full polar angle range without adopting the commonly used harmonic analyses. Our experimental results exhibited a strongly polar angular dependency of the spin orbit torque-driven effective fields observed from Ta or W/CoFeM/MgO frames.
A VSV-based Zika virus vaccine protects mice from lethal challenge
Authors: Emanuel Jackson , Callison Julie , Dowd Kimberly A. , Pierson Theodore C. , Feldmann Heinz , Marzi Andrea
Published: July 2018

Infection with Zika virus (ZIKV) is commonly mild in humans but has been associated with alarming negative health outcomes including Guillain-Barré syndrome in adults and microcephaly in fetuses. As such, developing a vaccine for ZIKV is a global public health priority. Recombinant vesicular stomatitis virus (VSV) expressing the Ebola virus (EBOV) glycoprotein (GP) has been successfully used as a vaccine platform in the past. In this study, two novel VSV-ZIKV vaccines were generated utilizing the favorable immune targeting of the existing VSV-EBOV vector. In addition to the EBOV GP, these new vaccines express the full-length pre-membrane and envelope proteins or pre-membrane and truncated soluble envelope proteins as antigens. Efficacy testing of both of the VSV vectors against ZIKV was conducted in IFNAR−/− mice and resulted in uniform protection when a single dose was administered 28 days prior to lethal challenge. Furthermore, this vaccine is fast-acting and can uniformly protect mice from lethal disease when administered as late as 3 days prior to ZIKV challenge. Thus, VSV-ZIKV vectors are promising vaccine candidates and should move forward along the licensure pathway.
Oropharyngeal microbiome evaluation highlights Neisseria abundance in active celiac patients
Authors: Iaffaldano Laura , Granata Ilaria , Pagliuca Chiara , Esposito Maria Valeria , Casaburi Giorgio , Salerno Giuliana , Colicchio Roberta , Piccirillo Marina , Ciacci Carolina , Del Vecchio Blanco Giovanna , Guarracino Mario Rosario , Salvatore Paola , Salvatore Francesco , D’Argenio Valeria , Sacchetti Lucia
Published: July 2018

We previously profiled duodenal microbiome in active (a-), gluten-free diet (GFD) celiac disease (CD) patients and controls finding higher levels of the ProteobacteriumNeisseria flavescensin a-CD patients than in the other two groups. Here, we investigate the oropharyngeal microbiome in CD patients and controls to evaluate whether this niche share microbial composition with the duodenum. We characterized by 16S rRNA gene sequencing the oropharyngeal microbiome in 14 a-CD, 22 GFD patients and 20 controls. Bacteroidetes, Proteobacteria and Firmicutes differed significantly between the three groups. In particular, Proteobacteria abounded in a-CD andNeisseriaspecies mostly accounted for this abundance (p < 0.001), whereas Bacteroidetes were more present in control and GFD microbiomes. Culture-based oropharyngeal microbiota analysis confirmed the greater abundance of Proteobacteria and ofNeisseriaspecies in a-CD. Microbial functions prediction indicated a greater metabolic potential for degradation of aminoacids, lipids and ketone bodies in a-CD microbiome than in control and GFD microbiomes, in which polysaccharide metabolism predominated. Our results suggest a continuum of a-CD microbial composition from mouth to duodenum. We may speculate that microbiome characterization in the oropharynx, which is a less invasive sampling than the duodenum, could contribute to investigate the role of dysbiosis in CD pathogenesis.
Efficient functional cyst formation of biliary epithelial cells using microwells for potential bile duct organisation in vitro
Authors: Rizki-Safitri Astia , Shinohara Marie , Miura Yasushi , Danoy Mathieu , Tanaka Minoru , Miyajima Atsushi , Sakai Yasuyuki
Published: July 2018

Establishing a bile duct in vitro is valuable to obtain relevant hepatic tissue culture systems for cell-based assays in chemical and drug metabolism analyses. The cyst constitutes the initial morphogenesis for bile duct formation from biliary epithelial cells (BECs) and serves the main building block of bile duct network morphogenesis from the ductal plate during embryogenesis in rodents. Cysts have been commonly cultured via Matrigel-embedded culture, which does not allow structural organisation and restricts the productivity and homogeneity of cysts. In this study, we propose a new method utilising oxygen permeable honeycomb microwells for efficient cyst establishment. Primary mouse BECs were seeded on four sizes of honeycomb microwell (46, 76, 126, and 326 µm-size in diameter). Matrigel in various concentrations was added to assist in cyst formation. The dimension accommodated by microwells was shown to play an important role in effective cyst formation. Cytological morphology, bile acid transportation, and gene expression of the cysts confirmed the favourable basic bile duct function compared to that obtained using Matrigel-embedded culture. Our method is expected to contribute to engineered in vitro liver tissue formation for cell-based assays.
Long-term reproducibility of GC-IPL thickness measurements using spectral domain optical coherence tomography in eyes with high myopia
Authors: Lee Min-Woo , Park Kee-Sup , Lim Hyung-Bin , Jo Young-Joon , Kim Jung-Yeul
Published: July 2018

Although ganglion cell inner plexiform layer (GC-IPL) analysis in the patients with high myopia is useful, there have been few reports to analyze of the reliability for long-term measured GC-IPL thickness. We aimed to analyze the long-term reproducibility of thickness measurements of the GC-IPL using spectral-domain optical coherence tomography (SD-OCT) in patients with high myopia and identify factors that affect such reproducibility. 99 eyes from 99 patients with high myopia without any other ophthalmc disorder such as glaucoma or retinal diseases were included. Two serial SD-OCT (Cirrus-HD) macular scans taken at ≧1 year intervals were analyzed. The intraclass correlation coefficient (ICC), coefficient of variation (CV), and test-retest standard deviation (TRTSD) of GC-IPL thickness measurements were assessed. The ICC, CV, and TRTSD of the mean GC-IPL thicknesses were 0.883, 5.9%, and 2.74, respectively. The ICCs of the six-sector GC-IPL thicknesses ranged from 0.740 to 0.904. The CVs of the minimal and all sectoral GC-IPL thicknesses were <10%. Measurement variances for the mean GC-IPL thicknesses showed significant relationshiups with chorioretinal atrophy and posterior staphyloma. There is high long-term reproducibility in GC-IPL thickness measurements using SD-OCT in high-myopia patients. The factors affecting this reproducibility include chorioretinal atrophy and posterior staphyloma.
Construction of Discrete Model of Human Pluripotency in Predicting Lineage-Specific Outcomes and Targeted Knockdowns of Essential Genes
Authors: Narad Priyanka , Anand Lakshay , Gupta Romasha , Sengupta Abhishek
Published: July 2018

A network consisting of 45 core genes was developed for the genes/proteins responsible for loss/gain of function in human pluripotent stem cells. The nodes were included on the basis of literature curation. The initial network topology was further refined by constructing an inferred Boolean model from time-series RNA-seq expression data. The final Boolean network was obtained by integration of the initial topology and the inferred topology into a refined model termed as the integrated model. Expression levels were observed to be bi-modular for most of the genes involved in the mechanism of human pluripotency. Thus, single and combinatorial perturbations/knockdowns were executed using anin silicoapproach. The model perturbations were validated with literature studies. A number of outcomes are predicted using the knockdowns of the core pluripotency circuit and we are able to establish the minimum requirement for maintenance of pluripotency in human. The network model is able to predict lineage-specific outcomes and targeted knockdowns of essential genes involved in human pluripotency which are challenging to perform due to ethical constraints surrounding human embryonic stem cells.