bluuebunny/crossref_metadata_2025 huggingface dataset:
Human DNA polymerase α interacts with mismatch repair proteins MSH2 and MSH6
Authors: Itkonen Harri M. , Kantelinen Jukka , Vaara Markku , Parkkinen Sinikka , Schlott Bernhard , Grosse Frank , Nyström Minna , Syväoja Juhani E. , Pospiech Helmut
Published: November 2016

High fidelity of genome duplication is ensured by cooperation of polymerase proofreading and mismatch repair (MMR) activities. Here, we show that human mismatch recognizing proteins MutS homolog 2 (MSH2) and MSH6 copurify and interact with replicative Pol α. This enzyme also is the replicative primase and replicates DNA with poor fidelity. We show that MSH2 associates with known human replication origins with different dynamics than DNA polymerase (Pol α). Furthermore, we explored the potential functional role of Pol α in the mismatch repair reaction using an in vitro mismatch repair assay and observed that Pol α promotes mismatch repair. Taken together, we show that human Pol α interacts with MSH2‐MSH6 complex and propose that this interaction occurs during the mismatch repair reaction.
Mitigation deterrence and the “moral hazard” of solar radiation management
Authors: McLaren Duncan
Published: November 2016

Fears of a moral hazard effect deterring mitigation have dogged solar radiation management (SRM) research since before 2006. Researchers have debated the significance and relevance of this concern from multiple disciplines and perspectives. This article explores this debate, highlighting the significance of policy goals and the actual and perceived substitutability of SRM for mitigation. The continuing problems in detecting mitigation deterrence in practice are noted. Different forms of moral hazard effect are distinguished, and the plausibility of mitigation galvanization considered. It is predicted that attention will turn to the situated, contingent expressions of mitigation deterrence and mitigation galvanization among different actors and at different scales; and to more sophisticated practical means to minimize the incidence and impacts of mitigation deterrence.
Proton cyclotron waves occurrence rate upstream from Mars observed by MAVEN: Associated variability of the Martian upper atmosphere
Authors: Romanelli N. , Mazelle C. , Chaufray J. Y. , Meziane K. , Shan L. , Ruhunusiri S. , Connerney J. E. P. , Espley J. R. , Eparvier F. , Thiemann E. , Halekas J. S. , Mitchell D. L. , McFadden J. P. , Brain D. , Jakosky B. M.
Published: November 2016

Measurements provided by the Magnetometer and the Extreme Ultraviolet Monitor (EUVM) on board the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft together with atomic H exospheric densities derived from numerical simulations are studied for the time interval from October 2014 up to March 2016. We determine the proton cyclotron waves (PCWs) occurrence rate observed upstream from Mars at different times. We also study the relationship with temporal variabilities of the high‐altitude Martian hydrogen exosphere and the solar EUV flux reaching the Martian environment. We find that the abundance of PCWs is higher when Mars is close to perihelion and decreases to lower and approximately constant values after the Martian Northern Spring Equinox. We also conclude that these variabilities cannot be associated with biases in MAVEN's spatial coverage or changes in the background magnetic field orientation. Higher H exospheric densities on the Martian dayside are also found when Mars is closer to perihelion, as a result of changes in the thermospheric response to variability in the ultraviolet flux reaching Mars at different orbital distances. A consistent behavior is also observed in the analyzed daily irradiances measured by the MAVEN EUVM. The latter trends point toward an increase in the planetary proton densities upstream from the Martian bow shock near perihelion. These results then suggest a method to indirectly monitor the variability of the H exosphere up to very high altitudes during large time intervals (compared to direct measurements of neutral particles), based on the observed abundance of PCWs.
Characteristic energy range of electron scattering due to plasmaspheric hiss
Authors: Ma Q. , Li W. , Thorne R. M. , Bortnik J. , Reeves G. D. , Kletzing C. A. , Kurth W. S. , Hospodarsky G. B. , Spence H. E. , Baker D. N. , Blake J. B. , Fennell J. F. , Claudepierre S. G. , Angelopoulos V.
Published: November 2016

We investigate the characteristic energy range of electron flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic electron flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed energy of significant electron decay increases with decreasing L shell and is well correlated with the energy band corresponding to the first adiabatic invariant μ = 4–200 MeV/G. The electron diffusion coefficients due to hiss scattering are calculated at L = 2–6, and the modeled energy band of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed energy range of electron decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2‐D Fokker‐Planck simulation of the electron phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV–1 MeV electrons with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower energies and more flattened distributions at higher energies. Our study provides reasonable estimates of the electron populations that can be most significantly affected by plasmaspheric hiss and the consequent electron decay profiles.
Asymmetry in the Farley‐Buneman dispersion relation caused by parallel electric fields
Authors: Forsythe Victoriya V. , Makarevich Roman A.
Published: November 2016

An implicit assumption utilized in studies of E region plasma waves generated by the Farley‐Buneman instability (FBI) is that the FBI dispersion relation and its solutions for the growth rate and phase velocity are perfectly symmetric with respect to the reversal of the wave propagation component parallel to the magnetic field. In the present study, a recently derived general dispersion relation that describes fundamental plasma instabilities in the lower ionosphere including FBI is considered and it is demonstrated that the dispersion relation is symmetric only for background electric fields that are perfectly perpendicular to the magnetic field. It is shown that parallel electric fields result in significant differences between the growth rates and phase velocities for propagation of parallel components of opposite signs. These differences are evaluated using numerical solutions of the general dispersion relation and shown to exhibit an approximately linear relationship with the parallel electric field near the E region peak altitude of 110 km. An analytic expression for the differences is also derived from an approximate version of the dispersion relation, with comparisons between numerical and analytic results agreeing near 110 km. It is further demonstrated that parallel electric fields do not change the overall symmetry when the full 3‐D wave propagation vector is reversed, with no symmetry seen when either the perpendicular or parallel component is reversed. The present results indicate that moderate‐to‐strong parallel electric fields of 0.1–1.0 mV/m can result in experimentally measurable differences between the characteristics of plasma waves with parallel propagation components of opposite polarity.
Solar wind‐driven Pc5 waves observed at a polar cap station and in the near cusp ionosphere
Authors: De Lauretis M. , Regi M. , Francia P. , Marcucci M. F. , Amata E. , Pallocchia G.
Published: November 2016

We present the results of a comparative study conducted in Antarctica by using the ULF geomagnetic field measurements at Terra Nova Bay (Altitude Adjusted Corrected Geomagnetic Coordinates latitude 80°S) and simultaneous data from the Super Dual Auroral Radar Network radar at South Pole Station. Pc5 waves observed at Terra Nova Bay around local magnetic noon, when the station is close to the dayside cusp, can be interpreted as spatial integrated signals, produced by ionospheric currents associated to field line resonances at somewhat lower latitudes. The radar, providing the Doppler velocities of ionospheric plasma over a range of geomagnetic latitudes, allows to detect the occurrence of such field line resonances. In the reported case, our analysis shows evidence of resonant signals in the ionosphere at 75°S and 76°S that find correspondence in frequency and time with the geomagnetic signals observed at Terra Nova Bay around local noon. During the period of interest, oscillations of the solar wind dynamic pressure at the same frequency are detected by Geotail, just upstream of the morning flank of the bow shock. All the observations are consistent with the interpretation of the signals at Terra Nova Bay in terms of signatures of field line resonances occurring at lower latitudes, driven by solar wind oscillations transmitted into the magnetosphere. We discuss also the possibility of an additional contribution to the signals at Terra Nova Bay, due to the direct propagation of the solar wind waves along the local open field line.
A new method to assess long‐term sea‐bottom vertical displacement in shallow water using a bottom pressure sensor: Application to Campi Flegrei, Southern Italy
Authors: Chierici Francesco , Iannaccone Giovanni , Pignagnoli Luca , Guardato Sergio , Locritani Marina , Embriaco Davide , Donnarumma Gian Paolo , Rodgers Mel , Malservisi Rocco , Beranzoli Laura
Published: November 2016

We present a new methodology using bottom pressure recorder (BPR) measurements in conjunction with sea level, water column, and barometric data to assess the long‐term vertical seafloor deformation to a few centimeters accuracy in shallow water environments. The method helps to remove the apparent vertical displacement on the order of tens of centimeters caused by the BPR instrumental drift and by seawater density variations. We have applied the method to the data acquired in 2011 by a BPR deployed at 96 m depth in the marine sector of the Campi Flegrei Caldera, during a seafloor uplift episode of a few centimeters amplitude, lasted for several months. The method detected a vertical uplift of the caldera of 2.5 ± 1.3 cm achieving an unprecedented level of precision in the measurement of the submarine vertical deformation in shallow water. The estimated vertical deformation at the BPR also compares favorably with data acquired by a land‐based GPS station located at the same distance from the maximum of the modeled deformation field. While BPR measurements are commonly performed in deep waters, where the oceanic noise is relatively low, and in areas with rapid, large‐amplitude vertical ground displacement, the proposed method extends the capability of estimating vertical uplifts from BPR time series to shallow waters and to slow deformation processes.
Modulation of atmospheric rivers near Alaska and the U.S. West Coast by northeast Pacific height anomalies
Authors: Mundhenk Bryan D. , Barnes Elizabeth A. , Maloney Eric D. , Nardi Kyle M.
Published: November 2016

Atmospheric rivers (ARs) can cause wide‐ranging impacts upon landfall at high northern latitudes, but comparatively little is known about the dynamics supporting these ARs in contrast to their midlatitude counterparts. Here ARs near the U.S. West Coast and the Gulf of Alaska during 1979–2015 are compared. ARs are found to occur in both regions with similar frequency, but with different seasonality. Composited atmospheric conditions from the NASA Modern‐Era Retrospective Analysis for Research and Applications data set reveal that a broad height anomaly over the northeast Pacific is influential to AR activity in both regions. When a positive height anomaly exists over the northeast Pacific, AR activity is often deflected poleward toward Alaska, while the U.S. West Coast experiences a decrease in AR activity. The opposing relationship also applies; that is, AR activity is decreased near Alaska and increased along the U.S. West Coast in the presence of a negative height anomaly. Quantitatively, nearly 79% of Gulf of Alaska ARs are associated with a positive northeast Pacific height anomaly and 86% of U.S. West Coast ARs are associated with a negative anomaly. Results suggest that this relationship applies across a range of time scales, to include subseasonal and interannual, not just with respect to individual transient waves. Both ARs and height anomalies are found to be associated with Rossby wave breaking, thereby dynamically linking AR activity with broader North Pacific dynamics.
Impact of global warming on the rise of volcanic plumes and implications for future volcanic aerosol forcing
Authors: Aubry Thomas J. , Jellinek A. Mark , Degruyter Wim , Bonadonna Costanza , Radić Valentina , Clyne Margot , Quainoo Adjoa
Published: November 2016

Volcanic eruptions have a significant impact on climate when they inject sulfur gases into the stratosphere. The dynamics of eruption plumes is also affected by climate itself, as atmospheric stratification impacts plumes' height. We use an integral plume model to assess changes in volcanic plume maximum rise heights as a consequence of global warming, with atmospheric conditions from an ensemble of global climate models, using three representative concentration pathways (RCP) scenarios. Predicted changes in atmospheric temperature profiles decrease the heights of tropospheric and lowermost stratospheric volcanic plumes and increase the tropopause height, for the RCP4.5 and RCP8.5 scenarios in the coming three centuries. Consequently, the critical mass eruption rate required to cross the tropopause increases by up to a factor of 3 for tropical regions and up to 2 for high‐latitude regions. A number of recent lower stratospheric plumes, mostly in the tropics (e.g., Merapi, 2010), would be expected to not cross the tropopause starting from the late 21st century, under RCP4.5 and RCP8.5 scenarios. This effect could result in a ≃5–25% decrease in the average SO2 flux into the stratosphere carried by small plumes, the frequency of which is larger than the rate of decay of volcanic stratospheric aerosol, and a ≃2–12% decrease of the total flux. Our results suggest the existence of a positive feedback between climate and volcanic aerosol forcing. Such feedback may have minor implications for global warming rate but can prove to be important to understand the long‐term evolution of volcanic atmospheric inputs.
Quantifying and reducing uncertainties in estimated soil CO2fluxes with hierarchical data‐model integration
Authors: Ogle Kiona , Ryan Edmund , Dijkstra Feike A. , Pendall Elise
Published: November 2016

Nonsteady state chambers are often employed to measure soil CO2fluxes. CO2concentrations (C) in the headspace are sampled at different times (t), and fluxes (f) are calculated from regressions ofCversustbased on a limited number of observations. Variability in the data can lead to poor fits and unreliablefestimates; groups with too few observations or poor fits are often discarded, resulting in “missing”fvalues. We solve these problems by fitting linear (steady state) and nonlinear (nonsteady state, diffusion based) models ofCversust, within a hierarchical Bayesian framework. Data are from the Prairie Heating and CO2Enrichment study that manipulated atmospheric CO2, temperature, soil moisture, and vegetation. CO2was collected from static chambers biweekly during five growing seasons, resulting in >12,000 samples and >3100 groups and associated fluxes. We comparefestimates based on nonhierarchical and hierarchical Bayesian (B versus HB) versions of the linear and diffusion‐based (L versus D) models, resulting in four different models (BL, BD, HBL, and HBD). Three models fit the data exceptionally well (R2 ≥ 0.98), but the BD model was inferior (R2 = 0.87). The nonhierarchical models (BL and BD) produced highly uncertainfestimates (wide 95% credible intervals), whereas the hierarchical models (HBL and HBD) produced very precise estimates. Of the hierarchical versions, the linear model (HBL) underestimatedfby ~33% relative to the nonsteady state model (HBD). The hierarchical models offer improvements upon traditional nonhierarchical approaches to estimatingf, and we provide example code for the models.
Sediment carbon sink in low‐density temperate eelgrass meadows (Baltic Sea)
Authors: Jankowska Emilia , Michel Loïc N. , Zaborska Agata , Włodarska‐Kowalczuk Maria
Published: November 2016

Seagrass meadows are highly productive habitats that can act as “blue carbon sinks” in coastal ecosystems by facilitating sedimentation and trapping particles. However, the magnitude and occurrence of these effects may be species and density dependent. The present study is the first estimation of seagrass sediment carbon sink in the temperate Zostera marina beds in the Baltic Sea. Several descriptors of organic matter characteristics, along with possible organic matter sources in the sediment were compared at vegetated and unvegetated bottoms. The 210Pb dating of the sediment has been used for accumulation rate assessment. The photopigments and POC concentrations in sediments were higher in vegetated bottoms. The SIAR (Stable Isotopes in R) mixing model based on nitrogen and carbon stable isotope values, indicated that higher percentages of organic matter originated from seagrass production in vegetated sediments (40–45%) compared to unvegetated ones (5–21%). The carbon stock in the upper 10 cm of the vegetated sediments ranged from 50.2 ± 2.2 to 228.0 ± 11.6 (g m−2), whereas the annual C accumulation amount from 0.84 ± 0.2 to 3.85 ± 1.2 (g m−2 yr−1). Our study shows that even the relatively weakly developed vegetation of the small temperate seagrass species enhance organic carbon concentration in the sediments. Estimated carbon stock was much lower than those reported for most of the seagrass meadows elsewhere, and the carbon burial rate was the lowest ever reported. Evidently, the global calculations of sediment carbon stock should be reconsidered by taking into account density and species‐related variability.
Snowpack fluxes of methane and carbon dioxide from high Arctic tundra
Authors: Pirk Norbert , Tamstorf Mikkel P. , Lund Magnus , Mastepanov Mikhail , Pedersen Stine H. , Mylius Maria R. , Parmentier Frans‐Jan W. , Christiansen Hanne H. , Christensen Torben R.
Published: November 2016

Measurements of the land‐atmosphere exchange of the greenhouse gases methane (CH4) and carbon dioxide (CO2) in high Arctic tundra ecosystems are particularly difficult in the cold season, resulting in large uncertainty on flux magnitudes and their controlling factors during this long, frozen period. We conducted snowpack measurements of these gases at permafrost‐underlain wetland sites in Zackenberg Valley (NE Greenland, 74°N) and Adventdalen Valley (Svalbard, 78°N), both of which also feature automatic closed chamber flux measurements during the snow‐free period. At Zackenberg, cold season emissions were 1 to 2 orders of magnitude lower than growing season fluxes. Perennially, CH4 fluxes resembled the same spatial pattern, which was largely attributed to differences in soil wetness controlling substrate accumulation and microbial activity. We found no significant gas sinks or sources inside the snowpack but detected a pulse in the δ13C‐CH4 stable isotopic signature of the soil's CH4 source during snowmelt, which suggests the release of a CH4 reservoir that was strongly affected by methanotrophic microorganisms. In the polygonal tundra of Adventdalen, the snowpack featured several ice layers, which suppressed the expected gas emissions to the atmosphere, and conversely lead to snowpack gas accumulations of up to 86 ppm CH4 and 3800 ppm CO2 by late winter. CH4 to CO2 ratios indicated distinctly different source characteristics in the rampart of ice‐wedge polygons compared to elsewhere on the measured transect, possibly due to geomorphological soil cracks. Collectively, these findings suggest important ties between growing season and cold season greenhouse gas emissions from high Arctic tundra.
Growth dynamics of black spruce (Picea mariana) in a rapidly thawing discontinuous permafrost peatland
Authors: Sniderhan Anastasia E. , Baltzer Jennifer L.
Published: November 2016

High‐latitude warming has led to radical changes in abiotic conditions influencing forest growth. In the North American boreal forest, widespread declines in forest productivity (particularly in western regions) and changing climate‐growth relationships have been documented. Previous studies have proposed that this decline can be attributed to drought stress as increasing temperatures may cause evapotranspirative demand to exceed available moisture. We used tree ring studies to document growth dynamics of black spruce, one of the most dominant boreal tree species, in a boreal peatland experiencing rapid permafrost thaw. We specifically look at how changing permafrost conditions influence growth. Growth of black spruce at this site has declined steadily since the mid‐1900s and exhibited a shift from positive responses to temperature pre‐1970 to predominantly negative responses in recent decades, despite precipitation increasing over time at this site. Our results show that there is no apparent effect of landscape position or rate of lateral permafrost thaw on growth trends of black spruce, despite gradients in soil moisture and active layer thickness across the mosaic of wetlands and drier permafrost plateaus at this site. However, this does not imply no effect of permafrost thaw on growth; our results support growing evidence that vertical permafrost thaw (i.e., active layer thickening) is causing drought stress in these slow‐growing, shallow‐rooted trees. To our knowledge, this study is the first to investigate permafrost as a driver of within‐site variability in growth‐climate responses, and we provide insight into the widespread growth declines and divergence of climate‐growth relationships in high‐latitude forests.
Soil N transformations and its controlling factors in temperate grasslands in China: A study from 15N tracing experiment to literature synthesis
Authors: Wang Jing , Wang Liang , Feng Xiaojuan , Hu Huifeng , Cai Zucong , Müller Christoph , Zhang Jinbo
Published: November 2016

Temperate grasslands in arid and semiarid regions cover about 40% of the total land area in China. So far, only a few studies have studied the N transformations in these important ecosystems. In the present study, soil gross N transformation rates in Inner Mongolia temperate grasslands in China were determined using a 15N tracing experiment and combined with a literature synthesis to identify the soil N transformation characteristics and their controlling factors in a global perspective. Our results showed that the rates of gross N mineralization and immobilization NH4+ were significantly lower, while autotrophic nitrification rates were significantly higher in Chinese temperate grassland soils compared to other regions in the world. In particular, the primary mineral N consumption processes, i.e., immobilization of NO3− and NH4+, and dissimilatory nitrate reduction to ammonium, were on average much lower in temperate grassland soils in China, compared to other temperate grassland regions. The reduced heterotrophic activity and microbial growth associated with lower soil organic carbon and arid climate (e.g., mean annual precipitation) were identified as the main factors regulating soil N cycling in the studied regions in China. To restrict NO3− accumulation and associated high risks of N losses in these arid and semiarid ecosystems in China, it is important to develop the regimes of soil organic C and water management that promote the retention of N in these grassland ecosystems.
Low contribution of internal metabolism to carbon dioxide emissions along lotic and lentic environments of a Mediterranean fluvial network
Authors: Gómez‐Gener Lluís , von Schiller Daniel , Marcé Rafael , Arroita Maite , Casas‐Ruiz Joan Pere , Staehr Peter Anton , Acuña Vicenç , Sabater Sergi , Obrador Biel
Published: November 2016

Inland waters are significant sources of carbon dioxide (CO2) to the atmosphere. CO2 supersaturation and subsequent CO2 emissions from inland waters can be driven by internal metabolism, external inputs of dissolved inorganic carbon (DIC) derived from the catchment, and other processes (e.g., internal geochemical reactions of calcite precipitation or photochemical mineralization of organic solutes). However, the sensitivity of the magnitude and sources of CO2 emissions to fluvial network hydromorphological alterations is still poorly understood. Here we investigated both the magnitude and sources of CO2 emissions from lotic (i.e., running waters) and lentic (i.e., stagnant waters associated to small dams) waterbodies of a Mediterranean fluvial network by computing segment‐scale mass balances of CO2. Our results showed that sources other than internal metabolism sustained most (82%) of the CO2 emissions from the studied fluvial network. The magnitude and sources of CO2 emissions in lotic waterbodies were highly dependent on hydrology, with higher emissions dominated by DIC inputs derived from the catchment during high flows and lower emissions partially fueled by CO2 produced biologically within the river during low flows. In contrast, CO2 emissions in lentic waterbodies were low, relatively stable over the time and the space, and dominated by DIC inputs from the catchment regardless of the different hydrological situations. Overall, our results stress the sensitivity of fluvial networks to human activities and climate change and particularly highlight the role of hydromorphological conditions on modulating the magnitude and sources of CO2 emissions from fluvial networks.
Coupling between lower‐tropospheric convective mixing and low‐level clouds: Physical mechanisms and dependence on convection scheme
Authors: Vial Jessica , Bony Sandrine , Dufresne Jean‐Louis , Roehrig Romain
Published: November 2016

Several studies have pointed out the dependence of low‐cloud feedbacks on the strength of the lower‐tropospheric convective mixing. By analyzing a series of single‐column model experiments run by a climate model using two different convective parametrizations, this study elucidates the physical mechanisms through which marine boundary‐layer clouds depend on this mixing in the present‐day climate and under surface warming. An increased lower‐tropospheric convective mixing leads to a reduction of low‐cloud fraction. However, the rate of decrease strongly depends on how the surface latent heat flux couples to the convective mixing and to boundary‐layer cloud radiative effects: (i) on the one hand, the latent heat flux is enhanced by the lower‐tropospheric drying induced by the convective mixing, which damps the reduction of the low‐cloud fraction, (ii) on the other hand, the latent heat flux is reduced as the lower troposphere stabilizes under the effect of reduced low‐cloud radiative cooling, which enhances the reduction of the low‐cloud fraction. The relative importance of these two different processes depends on the closure of the convective parameterization. The convective scheme that favors the coupling between latent heat flux and low‐cloud radiative cooling exhibits a stronger sensitivity of low‐clouds to convective mixing in the present‐day climate, and a stronger low‐cloud feedback in response to surface warming. In this model, the low‐cloud feedback is stronger when the present‐day convective mixing is weaker and when present‐day clouds are shallower and more radiatively active. The implications of these insights for constraining the strength of low‐cloud feedbacks observationally is discussed.
Superoxide increases angiotensin II AT1 receptor function in human kidney‐2 cells
Authors: Saleem Mohammad , Pokkunuri Indira , Asghar Mohammad
Published: November 2016

The redox‐sensitive Sp family transcription factor has been linked to the regulation of angiotensin II type 1 receptor (AT1R). However, the exact mechanism of AT1R regulation in renal cells is poorly understood. We tested the specificity of reactive oxygen species (ROS), superoxide vs. hydrogen peroxide (H2O2), and the specific role of Sp3 transcription factor, if any, in the regulation of AT1R in human kidney cells (HK2 cells). Superoxide dismutase (SOD) inhibitor diethyldithiocarbamate (DETC), but not H2O2 treatment, increased fluorescence levels of superoxide probe dihydroethidium (DHE). H2O2, but not DETC, treatment increased the fluorescence of the H2O2‐sensitive probe dichloro‐dihydro‐fluorescein (DCFH). These data suggest that SOD inhibition by DETC increases the superoxide but not H2O2 and exogenously added H2O2 is not converted to superoxide in renal cells. Furthermore, DETC, but not H2O2, treatment increased nuclear accumulation of Sp3, which was attenuated with the superoxide dismutase (SOD)‐mimetic tempol. DETC treatment also increased AT1R mRNA and protein levels that were attenuated with tempol, whereas H2O2 did not have any effects on AT1R mRNA. Moreover, Sp3 overexpression increased, while Sp3 depletion by siRNA decreased, protein levels of AT1R. In addition, Sp3 siRNA in the presence of DETC decreased AT1R protein expression. Furthermore, DETC treatment increased the levels of cell surface AT1R as measured by biotinylation and immunofluorescence studies. Angiotensin II increased PKC activity in vehicle‐treated cells that further increased in DETC‐treated cells, which was attenuated by AT1R blocker candesartan and SOD‐mimetic tempol. Taken together, our results suggest that superoxide, but not H2O2, via Sp3 up‐regulates AT1R expression and function in the renal cells.
Chromosomal Numerical Aberrations
Authors: Storchova Zuzana
Published: November 2016

Numerical aberrations (whole chromosomal aneuploidy) represent a significant proportion of chromosomal changes found in humans. These aberrations can occur as a consequence of chromosome segregation defects during cell division. Segregation errors that arise during reductive cell division, or meiosis, are upon fertilisation and subsequent embryo development constitutively present in all cells, resulting in whole organismal aneuploidy. Missegregation in mitosis leads to a mosaic distribution of aneuploidy in somatic cells. Aneuploidy is associated with pathological states in most organisms. Numerical aberrations represent a significant cause of pregnancy loss as well as abnormalities found in live births. Moreover, numerical aberrations are frequently found in ageing tissues or in tumour cells. Although the association of aneuploidy and cancer is known for almost a century, the dispute whether this is a cause or a consequence of cell transformation is still ongoing. Recently, new evidence is emerging that numerical aberrations significantly alter the physiology of eukaryotic cells and might indeed directly contribute to tumourigenesis.

Key Concepts

Numerical chromosomal aberrations result from errors in chromosome segregations.

Trisomy, monosomy and polyploidy are among the major causes of spontaneous human abortions.

Trisomies compatible with survival often result in multiple defects.

Numerical chromosomal aberrations significantly alter physiology of eukaryotic cells.

Numerical chromosomal aberrations are frequently found in cancer cells and can contribute to tumourigenesis.
Direct Labelling of Proteins with
125
I
Authors: Gjøen Tor , Berg Trond
Published: November 2016

To quantify binding to receptors and endocytosis of protein ligands, radioactive labelling with
125
I is still the most widely used technique. It combines high sensitivity with simple analysis and is the method of choice for most applications. Radioactive iodine can be directly coupled to tyrosine residues or via adducts that accumulate in the cells at their site of degradation. Two different methods for rapid direct labelling of proteins can be used for studying
in vivo
metabolism (blood clearance and degradation) or receptor kinetics and cellular uptake and degradation.

Key Concepts

Tracing labelled proteins
in vitro
and
in vitro
.

Protein binding to receptors.

Endocytosis and subcellular trafficking of proteins.

Lysosomal degradation.

Radioactive tracers.
Autophagy in Nonmammalian Systems
Authors: Mastrodonato Valeria , Morelli Elena , Vaccari Thomas
Published: November 2016

Autophagy, or ‘self‐eating’, is a catabolic process that enables lysosome‐mediated degradation of cytoplasmic contents and recycling of macromolecules to be used in essential cellular processes. This process enables cells to survive during nutrient restriction, participates in cell death during development and functions in clearance of protein aggregates and intracellular pathogens. Autophagy has been widely studied in yeast,
Drosophila
and
Caenorhabditis elegans
, and studies in these organisms have revealed regulation by multiple cellular pathways. These include cell growth regulators, such as the Class I PI3 kinase and target of rapamycin (Tor), as well as cell death regulators, including caspases. Defects in autophagy are associated with neurodegeneration, pathogen infection, cancer and reduced lifespan. Genetic experiments in model organisms have been critical in determining how autophagy functions in health and disease.

Key Concepts

Over 30
atg
genes have been shown to regulate autophagy.

Autophagy is induced in response to starvation and oxidative stress, enabling cells to recycle macromolecules and degrade damaged organelles.

Autophagy is required for steroid‐triggered removal of larval tissues during
Drosophila melanogaster
development.

Autophagosomes can sequester intracellular pathogens, which evade the cell's phagocytic machinery and traffic them to the lysosome for degradation.

Decreased autophagy leads to an inability to clear protein aggregates and mutant polyglutamine containing proteins from neurons in fly and worm neurodegeneration models.

Induction of autophagy in flies and worms can extend lifespan, whereas its block leads to increased neuronal cell death and reduced lifespan.

Autophagy has a context‐dependent role in tumourigenesis.
Molecular Biology of Breast Cancer
Authors: Caffarel Maria M , Pensa Sara , Wickenden Julie A , Watson Christine J
Published: November 2016

Breast cancer is a common disease affecting approximately 1 in 9 women at some time in their lives. Moreover, it is not a single disease but is characterised by distinct pathological types with different clinical outcomes. In the past decade, considerable progress has been made in understanding these different cancer subtypes at the molecular level. In particular, global gene expression studies have identified five predominant subtypes that have unique expression signatures. Unlike many other cancers, where a hierarchy of genetic mutations that leads to tumourigenesis has been identified, breast tumours have diverse genetic mutations that affect a variety of signalling pathways. Recently, large‐scale whole‐genome sequencing has revealed a set of potential driver mutations for breast cancer. Although some highly successful treatments have been developed, the challenge for the future is the development of individualised therapies that are specific to each patient's tumour type.

Key Concepts

Breast cancer is a heterogeneous disease characterised by distinct pathological types with different outcomes.

Breast tumours have diverse genetic mutations that affect a variety of signalling pathways.

Breast tumours can be classified into different subgroups according to their molecular expression profiles.

It is not clear whether specific molecular pathways establish the subtype of breast cancer or whether different cell types become transformed and give rise to each tumour subtype.

Breast cancer patients would benefit from individual therapeutic regimens designed to treat their particular type of cancer.
Environmental Performance Index
Authors: Hsu Angel , Zomer Alisa
Published: November 2016

The Environmental Performance Index (EPI) ranks 180 countries on nine priority environmental issues in two objectives including protection of human health and maintaining ecosystem vitality. The objective underlying the EPI is to move the environmental debate from emotional and rhetorical arguments to more data‐ and evidence‐based action that facilitates performance tracking and accountability of decision makers. Now in its sixth iteration, the EPI was among the first tools of its kind and is now a standard bearer for comparing and tracking country performance on international policies, including the Sustainable Development Goals (SDGs).
Fading of Affect Associated with Negative Child‐Related Memories Varies by Parental Child Abuse Potential
Authors: Skowronski John J. , Crouch Julie L. , Coley Sarah L. , Sasson Sapir , Wagner Michael F. , Rutledge Ericka , Cote Kreila , Miksys Christie , Milner Joel S.
Published: November 2016

Positive memories tend to hold their affective intensity across time better than negative memories, a phenomenon referred to as the fading affect bias (FAB). An initial study explored this bias in the context of parents' affective responses to memories involving their children. Specifically, parents (N = 90 for Study 1) were asked to recall three positive events and three negative events involving their children. Next, parents rated how positively or negatively they felt when each event occurred and at recall. Results revealed that parents at high risk of physical child abuse showed a smaller FAB than low‐risk parents. The smaller FAB effect observed among high‐risk parents occurred largely because affect associated with negative child‐related events faded minimally over time. This risk moderation effect did not emerge in a second study in which parents (N = 90 for Study 2) recalled general events that were not limited to events involving children. Copyright © 2016 John Wiley & Sons, Ltd.
Affects of Intricate Mass: The Strange Characteristics of the RMIT Mace and NGV Pavilion
Authors: Snooks Roland
Published: November 2016

The use of iterative multi‐agent algorithms to produce an accretion of intricate mass, rather than predefined form, is a key focus of current research at Roland Snooks's Melbourne studio. Here the architect and senior lecturer presents two projects, on very different scales, which his practice has developed using this ‘behavioural formation’ process, in collaboration with RMIT University. Defined by complex fibrous assemblages rather than surface or volume, they offer weird and wonderful atmospheric affects.
Bad Mood: On Design and ‘Empathy’
Authors: Bratton Benjamin H
Published: November 2016

Evocative design is not only concerned with enriching our experience of our environment: it can also be used to seduce us into consuming. Empathy is as crucial to this strategy of entrapment as it is to designing with more magnanimous aims in mind. Benjamin H Bratton, Professor of Visual Arts and Director of the Center for Design and Geopolitics at the University of California, San Diego, reflects on the matter, and considers whether the moodlessness that defines seemingly empathy‐free design is necessarily a bad thing.
Emanating Objects: The Atmospheric Ecosystems Generated by Gelatinous Orb and Buru Buru
Authors: Loverich Michael
Published: November 2016

The Bittertang Farm is a New York‘based experimental design firm that strives to bring happiness into the built environment by exploring the pleasurable, frothy features of the world around us. Michael Loverich, who cofounded the practice together with Antonio Torres, here describes two of its interventions. Taking the form of fantastical narrative ecosystems, they inspire new experiential moods.
The Awesome and Capricious Language of Past, Present and Future Digital Moods
Authors: Colletti Marjan
Published: November 2016

Can cultural progress be held back by linguistic limitations? Architect and educator Marjan Colletti, cofounder of London practice MAM‐arch, examines the nouns, adjectives and adjectival compounds used by the architectural profession during the first and second digital turns. He reflects on how restricted vocabularies can cause initially forward‐looking concepts to descend into the realm of doctrine and ‘‐isms’, and argues that true advancement requires constant evolution of the language employed to describe it.
Fast Synchrotron X‐Ray Tomography of Dynamic Processes in Liquid Aluminium Alloy Foam
Authors: Kamm Paul Hans , García‐Moreno Francisco , Neu Tillmann Robert , Heim Korbinian , Mokso Rajmund , Banhart John
Published: November 2016

Series of fast synchrotron X‐ray tomographies are taken continuously at a rate of up to 5 Hz, while aluminium alloy precursors are foamed in an X‐ray transparent setup for several minutes using infra‐red (IR) lasers for heating. The entire foaming process from the solid precursor to the expanded liquid foam is captured. The analysis of the sequence of tomographies is done with an emphasis on nucleation and bubble growth. In early stages of foaming, bubble and crack formation and evolution are observed. We analyze the nucleation stage and obtain quantitative results for the number of nucleation centers and their distribution and derive the nucleation rate as a function of time.
Predictive Design, Etch‐Free Fabrication of Through‐Hole Membrane with Ordered Pores and Hierarchical Layer Structure
Authors: Wong Him Cheng , Zhang Yue , Viasnoff Virgile , Low Hong Yee
Published: November 2016

Ultrathin through‐hole membranes with spatially ordered and monodisperse nanopores are attracting growing interests in academic studies and industrial applications. Herein, by adapting capillary driven mold‐based patterning techniques, the authors present, a facile, benchtop method for the fabrication of such membranes without elaborate post‐etching steps and costly instrumentations, which remain the intrinsic fabrication limitations in existing methods. The theory and experiment on the capillary driven imprint depth and timescale are in good agreement, thus providing predictive design guidelines to accurately control lateral (size, shape) and vertical (depth) dimensions of membrane pore features, using a singular master mold template. Another pressing limitation resides in the thin membrane's difficult detachment from the substrate after patterning. The membrane implementation bottleneck is resolved by a versatile sacrificial layer mediated transfer method that not only facilitates high fidelity transfer of ultrathin membranes onto various target substrates but also enable the assembly of membranes with ideal hierarchical layer structure in which each hierarchy has ordered pore morphology and distinct function. The fabrication approach described herein paves the way for a myriad of greater membrane functions not easily achieved through conventional membranes; especially in filtration, biology, and environmental applications that require exceptional size selectivity and unhindered flow pathways.
Fast–Slow Red Upconversion Fluorescence Modulation from Ho3+‐Doped Glass Ceramics upon Two‐Wavelength Excitation
Authors: Chen Zhi , Cui Wentao , Kang Shiliang , Zhang Hang , Dong Guoping , Jiang Chun , Zhou Shifeng , Qiu Jianrong
Published: November 2016

The control of one light field by another, ultimately at manipulating efficiently photon–photon interactions obsoleting traditional electronic interconnection approach, is an attractive area of research in the development of all‐optical network information science. Herein, an exquisite physical strategy is introduced to realize fast–slow optical modulation of red upconversion (UC) fluorescence from Ho3+:LaF3 nanocrystals embedded glass ceramics (GCs) tailoring by simultaneous two‐wavelength excitation at 980 and 1870 nm laser. An optical modulation of more than 2500% of the red UC fluorescence intensity and a fast response with rise time of 230 µs and decay time of 66 µs as well as a slow response with rise time of 23 ms and decay time of 6.65 ms in the red UC fluorescence signal is shown. The dynamic evolution analysis and theoretical simulations suggest that this fast‐slow optical modulation of red UC fluorescence is rooting from the presence of differentiation of the speed of electrons fully populated in the excited‐state 5I7 regulated by various pumping tactics. The fast–slow optical modulation of red UC fluorescence from Ho3+‐doped GCs, manipulating through two‐wavelength excitation at 980 and 1870 nm laser, may find novel application in future all‐optical fiber data processing in various optoelectronic fields.
Metal‐Free Synthesis of 3‐Arylquinolin‐2‐ones from N,2‐Diaryl‐ acrylamides via Phenyliodine(III) Bis(2,2‐dimethylpropanoate)‐ Mediated Direct Oxidative C−C Bond Formation
Authors: Cao Yang , Zhao Hui , Zhang‐Negrerie Daisy , Du Yunfei , Zhao Kang
Published: November 2016

Treatment of N,2‐diarylacrylamides with the organoiodine(III) compound phenyliodine(III) bis(2,2‐dimethylpropanoate) [PhI(O2C‐t‐Bu)2] and boron trifluoride etherate (BF3⋅Et2O) resulted in a direct and selective oxidative C(sp2)−C(sp2) bond formation leading to a convenient assemblage, under mild conditions, of the biologically important 3‐arylquinolin‐2‐one skeleton. Differing from the five‐membered oxindole products from oxidative cyclizations mediated by transition metals, this metal‐free approach realized a direct annulation of the N‐arylacrylamide into a six‐membered 3‐arylquinolin‐2‐one skeleton.

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Tunable Electronic Structures in Wrinkled 2D Transition‐Metal‐Trichalcogenide (TMT) HfTe3 Films
Authors: Wang Yu‐Qi , Wu Xu , Ge Yan‐Feng , Wang Ye‐Liang , Guo Haiming , Shao Yan , Lei Tao , Liu Chen , Wang Jia‐Ou , Zhu Shi‐Yu , Liu Zhong‐Liu , Guo Wei , Ibrahim Kurash , Yao Yu‐Gui , Gao Hong‐Jun
Published: November 2016

2D materials with anisotropic symmetry are likely, in general, to possess strain that is artificially adjustable in a single direction, inspiring strategies of artificial regulation of local structures and related properties. Herein, strain‐induced wrinkles in an anisotropic 2D transition‐metal‐trichalcogenide HfTe3 film are fabricated and illustrated for the first time. The corresponding localized electronic structures in the 1D corrugated wrinkles are revealed by a combination of experiment and simulation. The wrinkled HfTe3 film probably features electrical transport properties never before seen and useful for developing wrinkle‐based heterojunctions for novel nanoelectronic devices.