bluuebunny/crossref_metadata_2025 huggingface dataset:
Negligible effects of ocean acidification on Eurytemora affinis (Copepoda) offspring production
Authors: Almén A.-K. , Vehmaa A. , Brutemark A. , Bach L. , Lischka S. , Stuhr A. , Furuhagen S. , Paul A. , Bermúdez R. , Riebesell U. , Engström-Öst J.
Published: October 2015

Abstract. Ocean acidification is caused by increasing amounts of carbon dioxide dissolving in the oceans leading to lower seawater pH. We studied the effects of lowered pH on the calanoid copepod Eurytemora affinis during a mesocosm experiment conducted in a coastal area of the Baltic Sea. We measured copepod reproductive success as a function of pH, chlorophyll a concentration, diatom and dinoflagellate biomass, carbon to nitrogen (C : N) ratio of suspended particulate organic matter, as well as copepod fatty acid composition. The laboratory-based experiment was repeated four times during four consecutive weeks, with water and copepods sampled from pelagic mesocosms enriched with different CO2 concentrations. In addition, oxygen radical absorbance capacity (ORAC) of animals from the mesocosms was measured weekly to test whether the copepod's defence against oxidative stress was affected by pH. We found no effect of pH on offspring production. Phytoplankton biomass, as indicated by chlorophyll a concentration, had a strong positive effect. The concentration of polyunsaturated fatty acids in the females were reflected in the eggs and had a positive effect on offspring production, whereas monounsaturated fatty acids of the females were reflected in their eggs but had no significant effect. ORAC was not affected by pH. From these experiments we conclude that E. affinis seems robust against direct exposure to ocean acidification on a physiological level, for the variables covered in the study. E. affinis may not have faced acute pH stress in the treatments as the species naturally face large pH fluctuations.
Photochemical mineralisation in a humic boreal lake: temporal variability and contribution to carbon dioxide production
Authors: Groeneveld M. M. , Tranvik L. J. , Koehler B.
Published: October 2015

Abstract. Sunlight induces photochemical mineralisation of chromophoric dissolved organic matter (CDOM) to dissolved inorganic carbon (DIC) in inland waters, resulting in carbon dioxide (CO2) emissions to the atmosphere. Photochemical rate modelling is used to determine sunlight-induced CO2 emissions on large spatial and temporal scales. A sensitive model parameter is the wavelength-specific photochemical CDOM reactivity, the apparent quantum yield (AQY). The modelling studies so far assume that AQY spectra determined for single lakes and on single occasions represent larger spatial and temporal scales. Here, we studied a humic boreal lake in Sweden. We measured AQY spectra for photochemical DIC production monthly between June and November 2014 and parameterised a photochemical rate model. Photochemical reactivity increased slightly during the open water period, likely due to a high rainfall event with consecutive mixing in autumn that increased availability of highly photoreactive CDOM. However, the variability in AQY spectra over time was much smaller than previously reported variability in AQY spectra across lakes. Yet, using either the AQY spectrum from the least or from the most photoreactive water sample resulted in a 5-fold difference in simulated annual DIC photoproduction (2.0 ± 0.1 and 10.3 ± 0.7 g C m−2 yr−1, respectively). Using the monthly measured AQY spectrum to simulate DIC photoproduction for month-long time periods resulted in an apparent time lag between irradiance and DIC photoproduction. This suggested that temporal variability in AQY spectra occurs on shorter time scales. Therefore, we parameterised the model with the pooled AQY spectrum of six monthly measurements. Simulated DIC photoproduction for three years (2012–2014) averaged 4.5 ± 0.2 g C m−2 yr−1, which represented 3 % of the mean CO2 emissions from this lake. We conclude that (1) it may be recommendable to conduct repeated AQY measurements across the season for more accurate simulation of annual photochemical DIC production in lakes and (2), in agreement with previous studies, direct CDOM photomineralisation makes only a minor contribution to mean CO2 emissions from Swedish humic lakes.
Survey of the terrestrial habitats and vegetation of Shetland, 1974 – a framework for long term ecological monitoring
Authors: Wood C. M. , Bunce R. G. H.
Published: October 2015

Abstract. A survey of the natural environment was undertaken in Shetland in 1974, after concern was expressed that large scale development from the new oil industry could threaten the natural features of the islands. A framework was constructed by the Institute of Terrestrial Ecology on which to select samples for the survey. The vegetation and habitat data that were collected, along with the sampling framework, have recently been made public via the following DOIs: doi:10.5285/06fc0b8c-cc4a-4ea8-b4be-f8bd7ee25342 (Terrestrial habitat, vegetation and soil data from Shetland, 1974) and doi:10.5285/f1b3179e-b446-473d-a5fb-4166668da146 (Land Classification of Shetland 1974). In addition to providing valuable information about the state of the natural environment of Shetland, the repeatable and statistically robust methods developed in the survey were used to underpin the Countryside Survey, Great Britain's national long-term integrated environmental monitoring programme. The demonstration of the effectiveness of the methodology indicates that a repeat of the survey would yield statistics about ecological changes in the islands, such as those arising from the impacts of the oil industry. Currently no such figures are available although there is much information on the sociological impacts, as well as changes in agriculture.
A non-stationary earthquake probability assessment with the Mohr–Coulomb failure criterion
Authors: Wang J. P. , Xu Y.
Published: October 2015

Abstract. From theory to experience, earthquake probability associated with an active fault should be gradually increasing with time since the last event. In this paper, a new non-stationary earthquake assessment motivated/derived from the Mohr–Coulomb failure criterion is introduced. Different from other non-stationary earthquake analyses, the new model can more clearly define and calculate the stress states between two characteristic earthquakes. In addition to the model development and the algorithms, this paper also presents an example calculation to help explain and validate the new model. On the condition of best-estimate model parameters, the example calculation shows a 7.6 % probability for the Meishan fault in central Taiwan to induce a major earthquake in years 2015–2025, and if the earthquake does not occur by 2025, the earthquake probability will increase to 8 % in 2025–2035, which validates the new model that can calculate non-stationary earthquake probability as it should vary with time.
Techniques of Self-Knowledge in Nietzsche and Freud
Authors: Mitcheson Katrina
Published: October 2015

Both Nietzsche and Freud believe that our conscious experiences and actions are shaped by the activity of unconscious drives. Despite the significant differences in their understanding of drives and the obstacles faced uncovering them, there is sufficient common ground in their view of drives as multiple, contingent, and historically formed, to compare their methods of investigating them. For Nietzsche, solitude is essential to any project of self-knowledge, while Freud transplants the process of uncovering the activity of the drives from the loneliness of a metaphorical desert to the therapeutic relationship in the consulting room, relying on the effects of transference between analyst and analysand. If drives are relational, then understanding their activity seems to require exploring them in the context of relationships. These relationships, however, may constrain the process of investigation. By contrasting the methods of Freud and Nietzsche, I highlight dangers present in both approaches. Such awareness allows us to find ways to mitigate the inevitable bias that their methods introduce. I conclude that the limitations of a purely solitary or dialogical approach to self-knowledge point to the need to employ both solitude and dialogue to explore our drives, combining a capacity for solitude with a capacity to engage.
Promises and Obstacles of L1 Use in Language Classrooms: A State-of-the-Art Review
Authors: Ghobadi Mehdi , Ghasemi Hadi
Published: October 2015

Translation and language teaching techniques which take language learners’ first language (L1) as point of reference for teaching the second language (L2) have been long discouraged on the ground that these teaching techniques would end in the fossilization of L2 structure forms in the learner’s Interlanguage system. However, in recent years, the status of L1 use in L2 teaching and learning has revived as a result of the recognition that L1 can serve purposes in L2 teaching and learning (Hunt, 2012). In the last two decades, strong theoretical arguments have been posed for L1 use in language classrooms. Most of these arguments are based on the ground that L1 use can facilitate the processes of both L2 teaching and acquisition. Abundant research has been done in recent years to validate these theoretical arguments. The current paper would give a review of this research, with reference to three L1-based techniques for language teaching and learning that have appealed most to L2 researchers (i.e., translation, code switching, and L1 glossing). The conclusion drawn from this research is that language learners can benefit L1 use and L1-based techniques in their L2 acquisition. Further, along with the theoretical arguments and empirical evidence in defense of L1 use in language classrooms, L2 learners and teachers have begun to express more positive attitudes towards L1 use, and related techniques, in their own classrooms. Yet, there remain some challenges and obstacles for L1 use in language use. Suggestions are made as to how to address these challenges so that L2 pedagogy and use would benefit most from L1 use in language classrooms.
Therapeutic Potential of Human Adipose-Derived Stem/Stromal Cell Microspheroids Prepared by Three-Dimensional Culture in Non-Cross-Linked Hyaluronic Acid Gel
Authors: Mineda Kazuhide , Feng Jingwei , Ishimine Hisako , Takada Hitomi , Doi Kentaro , Kuno Shinichiro , Kinoshita Kahori , Kanayama Koji , Kato Harunosuke , Mashiko Takanobu , Hashimoto Ichiro , Nakanishi Hideki , Kurisaki Akira , Yoshimura Kotaro
Published: October 2015

Three-dimensional culture of mesenchymal stem/stromal cells for spheroid formation is known to enhance their therapeutic potential for regenerative medicine. Spheroids were prepared by culturing human adipose-derived stem/stromal cells (hASCs) in a non-cross-linked hyaluronic acid (HA) gel and compared with dissociated hASCs and hASC spheroids prepared using a nonadherent dish. Preliminary experiments indicated that a 4% HA gel was the most appropriate for forming hASC spheroids with a relatively consistent size (20–50 µm) within 48 hours. Prepared spheroids were positive for pluripotency markers (NANOG, OCT3/4, and SOX-2), and 40% of the cells were SSEA-3-positive, a marker of the multilineage differentiating stress enduring or Muse cell. In contrast with dissociated ASCs, increased secretion of cytokines such as hepatocyte growth factor was detected in ASC spheroids cultured under hypoxia. On microarray ASC spheroids showed upregulation of some pluripotency markers and downregulation of genes related to the mitotic cell cycle. After ischemia-reperfusion injury to the fat pad in SCID mice, local injection of hASC spheroids promoted tissue repair and reduced the final atrophy (1.6%) compared with that of dissociated hASCs (14.3%) or phosphate-buffered saline (20.3%). Part of the administered hASCs differentiated into vascular endothelial cells. ASC spheroids prepared in a HA gel contain undifferentiated cells with therapeutic potential to promote angiogenesis and tissue regeneration after damage.

Significance

This study shows the therapeutic value of human adipose-derived stem cell spheroids prepared in hyarulonic acid gel. The spheroids have various benefits as an injectable cellular product and show therapeutic potential to the stem cell-depleted conditions such as diabetic chronic skin ulcer.
Drawing Partially Embedded and Simultaneously Planar Graphs
Authors: Chan Timothy , Frati Fabrizio , Gutwenger Carsten , Lubiw Anna , Mutzel Petra , Schaefer Marcus
Published: October 2015

We investigate the problem of constructing planar drawings with few bends for two related problems, the partially embedded graph problem-to extend a straight-line planar drawing of a subgraph to a planar drawing of the whole graph-and the simultaneous planarity problem-to find planar drawings of two graphs that coincide on shared vertices and edges. In both cases we show that if the required planar drawings exist, then there are planar drawings with a linear number of bends per edge and, in the case of simultaneous planarity, with a number of crossings between any pair of edges which is bounded by a constant. Our proofs provide efficient algorithms if the combinatorial embedding of the drawing is given. Our result on partially embedded graph drawing generalizes a classic result by Pach and Wenger which shows that any planar graph can be drawn with a linear number of bends per edge if the location of each vertex is fixed.
Drawing Outer 1-planar Graphs with Few Slopes
Authors: Di Giacomo Emilio , Liotta Giuseppe , Montecchiani Fabrizio
Published: October 2015

A graph is outer 1-planar if it admits a drawing where each vertex is on the outer face and each edge is crossed by at most another edge. Outer 1-planar graphs are a superclass of the outerplanar graphs and a subclass of the planar partial 3-trees. We show that an outer 1-planar graph G of bounded degree ∆ admits an outer 1-planar straight-line drawing that uses O(∆) different slopes, which generalizes a previous result by Knauer et al. about the outerplanar slope number of outerplanar graphs (Knauer, Micek, and Walczak. CGTA, 2014). We also show that O(∆2) slopes suffice to construct a crossing-free straight-line drawing of G; the best known upper bound on the planar slope number of planar partial 3-trees of bounded degree ∆ is O(∆5) as proved by Jelínek et al. (V. Jelínek, E. Jelínková, J. Kratochvíl, B. Lidický, M. Tesar, and
T. Vyskocil. Graphs and Combinatorics, 2013).
Astrocyte activation in the anterior cingulate cortex and altered glutamatergic gene expression during paclitaxel-induced neuropathic pain in mice
Authors: Masocha Willias
Published: October 2015

Spinal astrocyte activation contributes to the pathogenesis of paclitaxel-induced neuropathic pain (PINP) in animal models. We examined glial fibrillary acidic protein (GFAP; an astrocyte marker) immunoreactivity and gene expression of GFAP, glutamate transporters and receptor subunits by real time PCR in the anterior cingulate cortex (ACC) at 7 days post first administration of paclitaxel, a time point when mice had developed thermal hyperalgesia. The ACC, an area in the brain involved in pain perception and modulation, was chosen because changes in this area might contribute to the pathophysiology of PINP. GFAP transcripts levels were elevated by more than fivefold and GFAP immunoreactivity increased in the ACC of paclitaxel-treated mice. The 6 glutamate transporters (GLAST, GLT-1 EAAC1, EAAT4, VGLUT-1 and VGLUT-2) quantified were not significantly altered by paclitaxel treatment. Of the 12 ionotropic glutamate receptor subunits transcripts analysed 6 (GLuA1, GLuA3, GLuK2, GLuK3, GLuK5 and GLuN1) were significantly up-regulated, whereas GLuA2, GLuK1, GLuK4, GLuN2A and GLuN2B were not significantly altered and GLuA4 was lowly expressed. Amongst the 8 metabotropic receptor subunits analysed only mGLuR8 was significantly elevated. In conclusion, during PINP there is astrocyte activation, with no change in glutamate transporter expression and differential up-regulation of glutamate receptor subunits in the ACC. Thus, targeting astrocyte activation and the glutamatergic system might be another therapeutic avenue for management of PINP.
Mammalian bone palaeohistology: a survey and new data with emphasis on island forms
Authors: Kolb Christian , Scheyer Torsten M. , Veitschegger Kristof , Forasiepi Analia M. , Amson Eli , Van der Geer Alexandra A.E. , Van den Hoek Ostende Lars W. , Hayashi Shoji , Sánchez-Villagra Marcelo R.
Published: October 2015

The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamidHippopotamus minorfrom the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island muridMikrotia magnafrom the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex.Leithiasp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorphProlagus oeningensisand three fossil species of insularProlagusdisplays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoidParaceratheriumsp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features ofSinomegaceros yabei, a large-sized deer from the Pleistocene of Japan closely related toMegaloceros, indicate a high growth rate. These examples and the synthesis of existing data show the potential of bone microstructure to reveal essential information on life history evolution. The bone tissue and the skeletochronological data of the sampled island species suggest the presence of various modes of bone histological modification and mammalian life history evolution on islands to depend on factors of island evolution such as island size, distance from mainland, climate, phylogeny, and time of evolution.
Significant mixed layer nitrification in a natural iron‐fertilized bloom of the Southern Ocean
Authors: Fripiat F. , Elskens M. , Trull T. W. , Blain S. , Cavagna A. ‐J. , Fernandez C. , Fonseca‐Batista D. , Planchon F. , Raimbault P. , Roukaerts A. , Dehairs F.
Published: October 2015

Nitrification, the microbially mediated oxidation of ammonium into nitrate, is generally expected to be low in the Southern Ocean mixed layer. This paradigm assumes that nitrate is mainly provided through vertical mixing and assimilated during the vegetative season, supporting the concept that nitrate uptake is equivalent to the new primary production (i.e., primary production which is potentially available for export). Here we show that nitrification is significant (~40–80% of the seasonal nitrate uptake) in the naturally iron‐fertilized bloom over the southeast Kerguelen Plateau. Hence, a large fraction of the nitrate‐based primary production is regenerated, instead of being exported. It appears that nitrate assimilation (light dependent) and nitrification (partly light inhibited) are spatially separated between the upper and lower parts, respectively, of the deep surface mixed layers. These deep mixed layers, extending well below the euphotic layer, allow nitrifiers to compete with phytoplankton for the assimilation of ammonium. The high contributions of nitrification to nitrate uptake are in agreement with both low export efficiency (i.e., the percentage of primary production that is exported) and low seasonal nitrate drawdown despite high nitrate assimilation.
Evidence and models for lower crustal flow beneath the Galápagos platform
Authors: Orellana‐Rovirosa Felipe , Richards Mark
Published: October 2015

The volcanic Galápagos Islands are constructed upon a broad platform, with their active westernmost islands marking the current position of the hotspot. Built upon young oceanic lithosphere (<15 Ma), this platform exhibits unique morphologic features including a system of stepped terraces on the southwestern escarpment with 3 km relief, contrasting with gentle slopes off the eastern platform toward the Carnegie Ridge. Considering horizontal lithostatic pressure differences associated with this relief, along with high temperatures within the young, hotspot‐affected lithosphere, it is likely that lower crustal flow contributes significantly to crustal deformation within the Galápagos platform. Using a 2‐D, isostatic, thin‐sheet approximation for the Stokes flow equation with (Newtonian) space‐time‐dependent viscosity, we suggest that the bathymetric rim along the eastern platform region (where gravimetry indicates Airy isostasy) near Española Island may be the expression of a mature lower crustal flow front developed over the last ∼3 Myr; horizontal mass displacements (∼50 km) associated with this crustal flow episode may have advected mantle plume geochemical signatures toward the southeast, and in directions not necessarily parallel to the hotspot track. Also, the stepped terraces along the southwestern platform may be explained by lower crustal flow‐associated backward tilting of the bathymetric surface that, although resulting in small angular changes (∼0.1°), effectively hinders the horizontal flow of lava sheets. This backward‐tilting process was likely restricted to the last ∼1 Ma or less, and may be a unique event involving extrusion of lavas from within the southwestward‐marching lower‐crustal flow front.
Zonally uniform tidal oscillations in the tropical stratosphere
Authors: Sakazaki Takatoshi , Sasaki Takuya , Shiotani Masato , Tomikawa Yoshihiro , Kinnison Douglas
Published: October 2015

By analyzing data from satellite measurements, a reanalysis, and a chemistry‐climate model, we found clear zonally uniform tidal signals in the tropical stratosphere, particularly during the Northern Hemisphere summer. Antisymmetric components with respect to the equator are dominant and are characterized by a vertical wavelength of ~15 km and a diurnal frequency. The temperature and vertical wind diurnal amplitudes in the stratosphere are 0.2–1 K and 1–7 mm s–1, respectively. The latter is generally larger than the climatological ascent motion in the stratosphere. The observed latitudinal and vertical structures can be explained by the second, propagating, antisymmetric Hough mode. These tidal oscillations should be carefully considered in analyses of zonal mean fields at a particular universal time.
Enhanced detection of terrestrial gamma‐ray flashes by AGILE
Authors: Marisaldi M. , Argan A. , Ursi A. , Gjesteland T. , Fuschino F. , Labanti C. , Galli M. , Tavani M. , Pittori C. , Verrecchia F. , D'Amico F. , Østgaard N. , Mereghetti S. , Campana R. , Cattaneo P.W. , Bulgarelli A. , Colafrancesco S. , Dietrich S. , Longo F. , Gianotti F. , Giommi P. , Rappoldi A. , Trifoglio M. , Trois A.
Published: October 2015

At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma‐Ray Flashes (TGFs). The configuration change was highly successful resulting in an increase of one order of magnitude in TGF detection rate. As expected, the largest fraction of the new events has short duration (<100 μs), and part of them has simultaneous association with lightning sferics detected by the World Wide Lightning Location Network. The new configuration provides the largest TGF detection rate surface density (TGFs/km2/yr) to date, opening prospects for improved correlation studies with lightning and atmospheric parameters on short spatial and temporal scales along the equatorial region.
Calculation of meridional neutral winds in the middle latitudes from the Irkutsk incoherent scatter radar
Authors: Shcherbakov A. A. , Medvedev A. V. , Kushnarev D. S. , Tolstikov M. V. , Alsatkin S. S.
Published: October 2015

This paper presents a consistent technique for velocity determination of meridional neutral winds from the Irkutsk incoherent scatter radar (IISR.) We calculated plasma drift velocity based on phase analysis of an autocorrelation function of an incoherent scatter signal. We also preliminary tested the described technique by determining several low‐orbit satellite velocities. Midlatitude meridional neutral winds were calculated using a “three‐beam” technique from the IISR velocity with taking into account motions due to electric fields across magnetic field lines in both meridional and zonal directions. It has been shown that an underestimated impact of the motions generated by electric fields can seriously interfere in determining wind velocities. The results obtained were compared with the modeled wind values.
Varying responses to Indian monsoons during the past 220 kyr recorded in deep‐sea sediments in inner and outer regions of the Gulf of Aden
Authors: Isaji Yuta , Kawahata Hodaka , Ohkouchi Naohiko , Ogawa Nanako O. , Murayama Masafumi , Inoue Kazuki , Tamaki Kensaku
Published: October 2015

Although the climate in the Arabian Sea is controlled primarily by the southwest monsoon, the southwest monsoon has little influence in the Gulf of Aden. To examine the different responses to monsoons between the Gulf of Aden and areas outside the gulf, a comprehensive data set of bulk organic and inorganic geochemistry, sea surface temperature, and δ15N of pheopigments was obtained from deep‐sea sediment cores recovered from inner and outer regions of the gulf. The results indicated that during the past 220 kyr, the influence of the southwest monsoon was stronger in the outer region of the gulf than in the inner region, which implies that the southwest monsoon trajectory has not changed substantially during that time period. Furthermore, influxes of O2‐depleted water from the Southern Ocean and the lateral advection of upwelled seawater also had limited influence in the inner region. In contrast, concentrations of lithogenic materials transported by the southwest monsoon were similar in the two regions. δ15N of pheopigments indicated that during the last glacial maximum, the southwest monsoon was weaker and the northeast monsoon was stronger than at present. A stronger southwest monsoon during interglacials enhanced primary productivity and may have caused anoxic conditions to develop in the Arabian Sea, as indicated by redox proxies in the outer region. Anoxic conditions also formed during MIS 3, but no increase in the primary productivity is indicated; therefore, another mechanism, such as an influx of O2‐depleted water from the Southern Ocean, may have been the cause.
Evaluation of autoconversion schemes in a single model framework with satellite observations
Authors: Michibata Takuro , Takemura Toshihiko
Published: October 2015

We examined the performance of autoconversion (mass transfer from cloud water to rainwater by the coalescence of cloud droplets) schemes in warm rain, which are commonly used in general circulation models. To exclude biases in the different treatment of the aerosol‐cloud‐precipitation‐radiation interaction other than that of the autoconversion process, sensitivity experiments were conducted within a single model framework using an aerosol‐climate model, MIROC‐SPRINTARS. The liquid water path (LWP) and cloud optical thickness have a particularly high sensitivity to the autoconversion schemes, and their sensitivity is of the same magnitude as model biases. In addition, the ratio of accretion to autoconversion (Acc/Aut ratio), a key parameter in the examination of the balance of microphysical conversion processes, also has a high sensitivity globally depending on the scheme used. Although the Acc/Aut ratio monotonically increases with increasing LWP, significantly lower ratio is observed in Kessler‐type schemes. Compared to satellite observations, a poor representation of cloud macrophysical structure and optically thicker low cloud are found in simulations with any autoconversion scheme. As a result of the cloud‐radiation interaction, the difference in the global mean net cloud radiative forcing (NetCRF) among the schemes reaches 10 Wm−2. The discrepancy between the observed and simulated NetCRF is especially large with a high LWP. The potential uncertainty in the parameterization of the autoconversion process is nonnegligible, and no formulation significantly improves the bias in the cloud radiative effect yet. This means that more fundamental errors are still left in other processes of the model.
Understanding the impact of plant competition on the coupling between vegetation and the atmosphere
Authors: van Loon Marloes P. , Dekker Stefan C. , Anten Niels P. R. , Rietkerk Max , Vilà‐Guerau de Arellano Jordi
Published: October 2015

Competition between plants for resources is an important selective force. As a result competition through natural selection determines vegetation functioning and associated atmospheric interactions. Our aim was to investigate how the coupling between vegetation and atmosphere is influenced by plant competition. Though included in some coupled vegetation‐atmosphere models, little attention has been paid to systematically study the impact of plant competition in determining the evolution of surface and atmospheric variables. We used a coupled vegetation‐atmosphere model and included a new representation of plant competition. We compared the model results with diurnal data from Ameriflux Bondville site over a growing season. Including competition improved LAI (Leaf Area Index) and net ecosystem exchange of CO2 (NEE) predictions; if competition was not considered, there were strong deviations from observations. Remarkably, competition increased LAI while it reduced whole stand photosynthesis, resulting in a less negative NEE. Finally, independent of competition, latent heat flux, surface temperature, specific humidity, and atmospheric CO2 are well reproduced by the model. Only the sensible heat flux was overestimated, mainly due to the imbalance in the surface energy balance that can lead to lower measured sensible heat fluxes. Sensitivity analysis showed that the importance of plant competition on model outcomes increases with more nitrogen and water availability and may differ between soil types. We thus quantified the potential effect of plant competition in a coupled vegetation‐atmosphere system and showed that it strongly influences this system, and therefore, we propose that competition should be considered in more vegetation‐atmosphere models.
A complete soil hydraulic model accounting for capillary and adsorptive water retention, capillary and film conductivity, and hysteresis
Authors: Rudiyanto  , Sakai Masaru , van Genuchten Martinus Th. , Alazba A. A. , Setiawan Budi Indra , Minasny Budiman
Published: October 2015

A soil hydraulic model that considers capillary hysteretic and adsorptive water retention as well as capillary and film conductivity covering the complete soil moisture range is presented. The model was obtained by incorporating the capillary hysteresis model of Parker and Lenhard into the hydraulic model of Peters‐Durner‐Iden (PDI) as formulated for the van Genuchten (VG) retention equation. The formulation includes the following processes: capillary hysteresis accounting for air entrapment, closed scanning curves, nonhysteretic sorption of water retention onto mineral surfaces, a hysteretic function for the capillary conductivity, a nonhysteretic function for the film conductivity, and a nearly nonhysteretic function of the conductivity as a function of water content (θ) for the entire range of water contents. The proposed model only requires two additional parameters to describe hysteresis. The model was found to accurately describe observed hysteretic water retention and conductivity data for a dune sand. Using a range of published data sets, relationships could be established between the capillary water retention and film conductivity parameters. Including vapor conductivity improved conductivity descriptions in the very dry range. The resulting model allows predictions of the hydraulic conductivity from saturation until complete dryness using water retention parameters.
Learning to Ask Questions: A Pathway to and through College for Students in Low–Income Communities
Authors: Santana Luz
Published: October 2015

Luz Santana shares the Question Formulation Technique, a process for supporting students in learning how to ask their own questions, a foundational skill for academic success
Controllable Growth of Perovskite Films by Room‐Temperature Air Exposure for Efficient Planar Heterojunction Photovoltaic Cells
Authors: Yang Bin , Dyck Ondrej , Poplawsky Jonathan , Keum Jong , Das Sanjib , Puretzky Alexander , Aytug Tolga , Joshi Pooran C. , Rouleau Christopher M. , Duscher Gerd , Geohegan David B. , Xiao Kai
Published: October 2015

A two‐step solution processing approach has been established to grow void‐free perovskite films for low‐cost high‐performance planar heterojunction photovoltaic devices. A high‐temperature thermal annealing treatment was applied to drive the diffusion of CH3NH3I precursor molecules into a compact PbI2 layer to form perovskite films. However, thermal annealing for extended periods led to degraded device performance owing to the defects generated by decomposition of perovskite into PbI2. A controllable layer‐by‐layer spin‐coating method was used to grow “bilayer” CH3NH3I/PbI2 films, and then drive the interdiffusion between PbI2 and CH3NH3I layers by a simple air exposure at room temperature for making well‐oriented, highly crystalline perovskite films without thermal annealing. This high degree of crystallinity resulted in a carrier diffusion length of ca. 800 nm and a high device efficiency of 15.6 %, which is comparable to values reported for thermally annealed perovskite films.
Potentialgestützte DNA‐Immobilisierung als Voraussetzung für eine schnelle und kontrollierte Bildung von DNA‐Monoschichten
Authors: Jambrec Daliborka , Gebala Magdalena , La Mantia Fabio , Schuhmann Wolfgang
Published: October 2015

Die Immobilisierung von DNA‐Einzelsträngen auf Goldoberflächen kann hochreproduzierbar mithilfe einer geeigneten Potentialpulssequenz substanziell beschleunigt werden. Die gewünschte Oberflächenbelegung mit einzelsträngiger DNA lässt sich innerhalb weniger Minuten erhalten. Entscheidend ist das Verständnis der zugrundliegenden Prozesse. Ein von uns vorgeschlagenes Modell berücksichtigt sowohl die Rolle der Ionen in der Umgebung der elektrifizierten Grenzfläche und der DNA‐Stränge als auch die Distanz, in der das angelegte Potential einen Einfluss auf die DNA‐Einzelstränge in der Nähe der elektrifizierten Grenzfläche hat. Auch die Verschiebung des Nullladungspotentials der Elektrode infolge der Oberflächenmodifizierung durch die DNA‐Stränge wird berücksichtigt und ist von besonderer Bedeutung. Die Kontrolle der Oberflächenbedeckung der Einzelstrang‐DNA, in Kombination mit der erreichten Geschwindigkeit und Reproduzierbarkeit, ist eine Voraussetzung für verbesserte DNA‐basierte Bioassays.
Synthetic Covalent and Non‐Covalent 2D Materials
Authors: Boott Charlotte E. , Nazemi Ali , Manners Ian
Published: October 2015

The creation of synthetic 2D materials represents an attractive challenge that is ultimately driven by their prospective uses in, for example, electronics, biomedicine, catalysis, sensing, and as membranes for separation and filtration. This Review illustrates some recent advances in this diverse field with a focus on covalent and non‐covalent 2D polymers and frameworks, and self‐assembled 2D materials derived from nanoparticles, homopolymers, and block copolymers.
Solid‐phase preparation method of silica‐supported 2,2′‐methylenebis(6‐tert‐butyl‐4‐methyl‐phenol) and its antioxidative behavior in styrene‐butadiene rubber
Authors: Jia Zhixin , Luo Qiwen , Wang Song , Chen Yongjun , Zhou Xiangyang , Liu Mingxian , Luo Yuanfang , Jia Demin
Published: October 2015

A solid‐phase preparation method is applied to the synthesis of a novel supported rubber antioxidant, silica–supported 2,2′‐methylenebis(6‐tert‐butyl‐4‐methyl‐phenol) (SiO2‐2246), by directly reacting 2,2′‐methylenebis (6‐tert‐butyl‐4‐methyl‐phenol)(antioxidant 2246) with silica. FTIR, Raman spectroscopy and TGA confirm that the antioxidant 2246 is chemically bonded on the surface of the silica particles. The SEM observation shows that the SiO2‐2246 is homogeneously dispersed in the styrene‐butadiene rubber (SBR) matrix. The results of the apparent activation energy and the attenuated total reflectance infrared spectrometry indicate that the antioxidative efficiency of the SiO2‐2246 in SBR is superior to the corresponding low‐molecular‐weight 2246. The thermal oxidative stability of the SBR/SiO2‐2246 composites is much higher than that of the SBR/SiO2/2246 composites by comparing their mechanical properties retentions and crosslinking densities. Additionally, the advantages of SiO2‐2246 also include low migration, low volatility, and low pollution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43014.
Synthesis and properties of acrylate‐acrylic acid‐acrylate triblock copolymers with gemini structure by RAFT polymerization
Authors: Yu Erlei , Mamat Xamxikamar , Zhi Keke , Zhang Xuemin , Zhang Yagang , Eli Wumanjiang
Published: October 2015

A class of gemini structure block copolymers with a trithiocarbonate ester spacer group had been synthesized with S, S′‐bis (R, R′‐dimethylacetic acid) trithiocarbonate as reversible addition fragmentation chain transfer agents and acrylic acid as the second monomer. These triblock copolymers were characterized by 1H NMR spectroscopy, gel permeation chromatography in terms of their compositions, molecular weights and behaviour at the air–water interface. The results showed that the weight‐average molecular weight was larger than theoretical molecular as the acrylate side chain increased. The polymer neutralized by sodium hydroxide solution had low critical micelle concentration which was <10−2 mol L−1 in water. TEM and DLS showed that it formed a special micelle structure with large pore structure which might lead to low surface tension and critical micelle concentration in water. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43017.
Is exploratory search different? A comparison of information search behavior for exploratory and lookup tasks
Authors: Athukorala Kumaripaba , Głowacka Dorota , Jacucci Giulio , Oulasvirta Antti , Vreeken Jilles
Published: October 2015

Exploratory search is an increasingly important activity yet challenging for users. Although there exists an ample amount of research into understanding exploration, most of the major information retrieval (IR) systems do not provide tailored and adaptive support for such tasks. One reason is the lack of empirical knowledge on how to distinguish exploratory and lookup search behaviors in IR systems. The goal of this article is to investigate how to separate the 2 types of tasks in an IR system using easily measurable behaviors. In this article, we first review characteristics of exploratory search behavior. We then report on a controlled study of 6 search tasks with 3 exploratory—comparison, knowledge acquisition, planning—and 3 lookup tasks—fact‐finding, navigational, question answering. The results are encouraging, showing that IR systems can distinguish the 2 search categories in the course of a search session. The most distinctive indicators that characterize exploratory search behaviors are query length, maximum scroll depth, and task completion time. However, 2 tasks are borderline and exhibit mixed characteristics. We assess the applicability of this finding by reporting on several classification experiments. Our results have valuable implications for designing tailored and adaptive IR systems.
Concentration‐mediated multicolor fluorescence polymer carbon dots
Authors: Jeong Chan Jin , Lee Gibaek , In Insik , Park Sung Young
Published: October 2015

Polymer dots (PDs) showing concentration‐mediated multicolor fluorescence were first prepared from sulfuric acid‐treated dehydration of Pluronic® F‐127 in a single step. Pluronic‐based PDs (P‐PDs) showed high dispersion stability in solvent media and exhibited a fluorescence emission that was widely tunable from red to blue by adjusting both the excitation wavelengths and the P‐PD concentration in an aqueous solution. This unique fluorescence behavior of P‐PDs might be a result of cross‐talk in the fluorophores of the poly(propylene glycol)‐rich core inside the P‐PD through either energy transfer or charge transfer. Reconstruction of the surface energy traps of the P‐PDs mediated through aggregation may lead to a new generation of carbon‐based nanomaterials possessing a fluorescence emission and tunable by adjusting the concentration. These structures may be useful in the design of multifunctional carbon nanomaterials with tunable emission properties according to a variety of internal or external stimuli. Copyright © 2015 John Wiley & Sons, Ltd.
Comparison of 10,11‐Dehydrocurvularin Polyketide Synthases from Alternaria cinerariae and Aspergillus terreus Highlights Key Structural Motifs
Authors: Cochrane Rachel V. K. , Gao Zhizeng , Lambkin Gareth R. , Xu Wei , Winter Jaclyn M. , Marcus Sandra L. , Tang Yi , Vederas John C.
Published: October 2015

Iterative type I polyketide synthases (PKSs) from fungi are multifunctional enzymes that use their active sites repeatedly in a highly ordered sequence to assemble complex natural products. A phytotoxic macrolide with anticancer properties, 10,11‐dehydrocurvularin (DHC), is produced by cooperation of a highly reducing (HR) iterative PKS and a non‐reducing (NR) iterative PKS. We have identified the DHC gene cluster in Alternaria cinerariae, heterologously expressed the active HR PKS (Dhc3) and NR PKS (Dhc5) in yeast, and compared them to corresponding proteins that make DHC in Aspergillus terreus. Phylogenetic analysis and homology modeling of these enzymes identified variable surfaces and conserved motifs that are implicated in product formation.
Tuning and Switching Enantioselectivity of Asymmetric Carboligation in an Enzyme through Mutational Analysis of a Single Hot Spot
Authors: Wechsler Cindy , Meyer Danilo , Loschonsky Sabrina , Funk Lisa‐Marie , Neumann Piotr , Ficner Ralf , Brodhun Florian , Müller Michael , Tittmann Kai
Published: October 2015

Enantioselective bond making and breaking is a hallmark of enzyme action, yet switching the enantioselectivity of the reaction is a difficult undertaking, and typically requires extensive screening of mutant libraries and multiple mutations. Here, we demonstrate that mutational diversification of a single catalytic hot spot in the enzyme pyruvate decarboxylase gives access to both enantiomers of acyloins acetoin and phenylacetylcarbinol, important pharmaceutical precursors, in the case of acetoin even starting from the unselective wild‐type protein. Protein crystallography was used to rationalize these findings and to propose a mechanistic model of how enantioselectivity is controlled. In a broader context, our studies highlight the efficiency of mechanism‐inspired and structure‐guided rational protein design for enhancing and switching enantioselectivity of enzymatic reactions, by systematically exploring the biocatalytic potential of a single hot spot.
Chronic total uterine inversion in an adolescent
Authors: Birge Ozer , Merdin Alparslan
Published: October 2015

Key Clinical Message

Uterine inversion is rarely seen in adolescents in western countries. But it might be seen in teenagers and adolescents due to poor conditions and early pregnancies in Africa. And early troubleshooting chronic uterine inversion represents an early resolution of the problem and allows planning pregnancy without complications.
Aberration‐Corrected Transmission Electron Microscopy and In Situ XAFS Structural Characterization of Pt/γ‐Al2O3 Nanoparticles
Authors: Sinkler Wharton , Sanchez Sergio I. , Bradley Steven A. , Wen Jianguo , Mishra Bhoopesh , Kelly Shelly D. , Bare Simon R.
Published: October 2015

Aberration‐corrected (AC) STEM, AC TEM and in situ X‐ray absorption fine structure spectroscopy (XAFS) were used to characterize the Pt clusters present on a 0.35 wt % Pt on γ‐alumina support after reduction in hydrogen at 700 °C. STEM high‐angle annular dark field imaging shows that cluster formation takes place at temperatures up to approximately 350 °C, and this is followed by gradual growth in cluster size for heat treatments in hydrogen up to 700 °C. The STEM data show that after 700 °C reduction the Pt clusters are present in a narrow size distribution centered at 0.88 nm, and using a method involving a redistribution of the Pt atoms using a high electron dosage in the STEM, it is shown that the clusters are present in two‐dimensional morphology. This conclusion is verified using intensity line scans. The in situ extended X‐ray absorption fine structure data are in good agreement with these observations. High‐resolution AC–TEM, which uses a broad coherent electron beam, and can thus offer advantages relative to STEM for structure determination of fine clusters, supported by image simulations of through‐focus series, were used to analyze the structures of Pt particles. The structures determined by using AC–TEM are consistent with STEM and EXAFS data in having a flat two‐dimensional morphology. Comparison of AC–STEM and AC TEM data for the same 700 °C reduced sample suggests that parallel‐beam TEM mode of imaging may be advantageous because of the less pronounced beam‐induced structural rearrangements that occur when imaging with a fine STEM probe.
Expedient Mechanosynthesis of N,N‐Dialkyl Imidazoliums and Silver(I)–Carbene Complexes in a Ball‐Mill
Authors: Beillard Audrey , Golliard Ethan , Gillet Valentin , Bantreil Xavier , Métro Thomas‐Xavier , Martinez Jean , Lamaty Frédéric
Published: October 2015

The absence of solvent, associated with intensive mechanical agitation, allowed the first mechanosynthesis of high‐value silver(I)–carbene complexes and the corresponding N,N‐dialkylimidazolium precursors. This procedure gave outstanding results in terms of yield and reaction time, when compared to solution‐based conditions previously described in literature, and was generalized to unprecedented compounds. Silver(I)–carbene complexes could either be obtained from N,N‐dialkylimidazolium salts or directly from imidazole and alkyl halides in a one‐pot two‐step procedure without isolating the imidazolium intermediate. Additionally, an efficient one‐pot three‐step sequence, including imidazole alkylation, silver metalation, and transmetalation is reported.
Unexpected Efficiency of a Luminescent Samarium(III) Complex for Combined Visible and Near‐Infrared Biphotonic Microscopy
Authors: Bui Anh Thy , Grichine Alexei , Brasselet Sophie , Duperray Alain , Andraud Chantal , Maury Olivier
Published: October 2015

An original samarium(III) complex based on a triazacyclononane platform functionalized with a charge‐transfer antenna chromophore exhibited optimized brightness and was successfully used as an emissive species for two‐photon microscopy experiments in both the visible and near‐infrared spectral ranges.