bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the effect of air pollution controls on trends in shortwave radiation over the United States from 1995 through 2010 from multiple observation networks
Authors: Gan C.-M. , Pleim J. , Mathur R. , Hogrefe C. , Long C. N. , Xing J. , Roselle S. , Wei C.
Published: September 2013

Abstract. Long term datasets of all-sky and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction and aerosol optical depth (AOD) are analyzed together with surface concentration from several networks (e.g. SURFRAD, CASTNET, IMPROVE and ARM) in the United States (US). Seven states with varying climatology are selected to better understand the effects of aerosols and clouds on SW radiation. This analysis aims to assess the effects of reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) over the past 16 yr across the US on trends in SW radiation. The SO2 and NOx emission data show decreasing trends from 1995 to 2010 which indirectly validates the effects of the Clean Air Act (CAA) in the US. Meanwhile, the total column AOD and surface total PM2.5 observations also show decreasing trends in the eastern US but slightly increasing trends in the western US. Moreover, measured surface concentrations of several other pollutants (i.e. SO2, SO4 and NOx) have the same behavior as the AOD and total PM2.5. First, all-sky downwelling SW radiation is assessed together with the cloud cover. Results of this analysis show strong increasing trends in all-sky downwelling SW radiation with decreasing trends in cloud cover. However, since observations of both all-sky direct and diffuse SW radiation are increasing, there may be other factors contributing to the radiation trends in addition to the decreasing trends in overall cloud cover. To investigate the role of direct radiative effects of aerosols, clear-sky downwelling radiation is analyzed so that cloud effects are eliminated. However, similar increasing trends in clear-sky direct and diffuse SW radiation are observed. While significantly decreasing trends in AOD and surface concentration along with increasing SW radiation (both all-sky and clear-sky) in the eastern US during 1995–2010 imply the occurrence of direct aerosol mediated "brightening", the increasing trends of both all-sky and clear sky diffuse SW radiation contradicts this conclusion since diffuse radiation would be expected to decrease as aerosols direct effects decrease. After investigating several confounding factors, the increasing trend in diffuse SW may be due to more high-level cirrus from increasing air traffic over the US. In contrast to the eastern US, radiation observations in the western US do not show any indication of "brightening" which is consistent with the observations (e.g. AOD, PM2.5 and surface concentration) that show the aerosol loading increasing slightly. This outcome is not unexpected because the CAA controls were mainly aimed at reducing air pollutants emission in the eastern US and air pollutant level in the western US are much lower.
Injection heights of springtime biomass burning plumes over the Peninsular Southeast Asia and their impacts on pollutant long-range transport
Authors: Jian Y. , Fu T.-M.
Published: September 2013

Abstract. We analyzed observations from the Multi-angle Imaging SpectroRadiometer (MISR) to determine the injection heights of biomass burning smoke plumes over the Peninsular Southeast Asia (PSEA) in spring, with the goal of evaluating the impacts on pollutant long-range transport. We retrieved the heights of twenty-two thousand MISR smoke pixels from 607 smoke plumes over the PSEA during February to April of the years 2001–2010. Forty-five percent of the analyzed smoke pixels were above the local mean boundary layer (1 km) at MISR overpass time (10:30 a.m. local time). We used the GEOS-Chem model to simulate the transport of PSEA biomass burning pollutants in March 2001. We found that the direct injection of 40% of the PSEA biomass burning emissions had little impact on the long-range transport of CO to downwind regions, compared to a control simulation where all biomass burning emissions were released in the boundary layer. This was because CO at the surface over the PSEA was efficiently lifted into the free troposphere by deep convection associated with synoptic-scale weather systems. For pollutants with lifetimes shorter than the synoptic timescale, such as black carbon aerosol (BC), their long-range transport was much more sensitive to the initial plume injection height. The direct injection of NOx from PSEA biomass burning into the free troposphere drove increased formation and transport of PAN, which in turn led to significant increases of ozone over downwind southern China and northwestern Pacific. The Pacific subtropical high transported PSEA biomass burning pollutants to the marine boundary layer over the tropical northwestern Pacific. We compared our model results to aircraft measurements over the northwestern Pacific during the TRACE-P campaign (March 2001). The direct injection of 40% of the PSEA biomass burning pollutants in the free troposphere in the model led to a more pronounced BC peak at 3 km over the northwestern Pacific, which was in better agreement with the aircraft observations compared to the control simulation. Our analyses highlighted the point that the injection heights of smoke plumes pose large uncertainty to the interpretation of BC measurements downwind of biomass burning regions.
Multivariate benthic ecosystem functioning in the Arctic – benthic fluxes explained by environmental parameters in the southeastern Beaufort Sea
Authors: Link H. , Chaillou G. , Forest A. , Piepenburg D. , Archambault P.
Published: September 2013

Abstract. The effects of climate change on Arctic marine ecosystems and their biogeochemical cycles are difficult to predict given the complex physical, biological and chemical interactions among the ecosystem components. We studied benthic biogeochemical fluxes in the Arctic and the influence of short-term (seasonal to annual), long-term (annual to decadal) and other environmental variability on their spatial distribution to provide a baseline for estimates of the impact of future changes. In summer 2009, we measured fluxes of dissolved oxygen, nitrate, nitrite, ammonia, soluble reactive phosphate and silicic acid at the sediment–water interface at eight sites in the southeastern Beaufort Sea at water depths from 45 to 580 m. The spatial pattern of the measured benthic boundary fluxes was heterogeneous. Multivariate analysis of flux data showed that no single or reduced combination of fluxes could explain the majority of spatial variation, indicating that oxygen flux is not representative of other nutrient sink–source dynamics. We tested the influence of eight environmental parameters on single benthic fluxes. Short-term environmental parameters (sinking flux of particulate organic carbon above the bottom, sediment surface Chl a) were most important for explaining oxygen, ammonium and nitrate fluxes. Long-term parameters (porosity, surface manganese and iron concentration, bottom water oxygen concentrations) together with δ13Corg signature explained most of the spatial variation in phosphate, nitrate and nitrite fluxes. Variation in pigments at the sediment surface was most important to explain variation in fluxes of silicic acid. In a model including all fluxes synchronously, the overall spatial distribution could be best explained (57%) by the combination of sediment Chl a, phaeopigments, δ13Corg, surficial manganese and bottom water oxygen concentration. We conclude that it is necessary to consider long-term environmental variability along with rapidly ongoing environmental changes to predict the flux of oxygen and nutrients across Arctic sediments even at short timescales. Our results contribute to improve ecological models predicting the impact of climate change on the functioning of marine ecosystems.
Expressions of climate perturbations in western Ugandan crater lake sediment records during the last 1000 yr
Authors: Mills K. , Ryves D. B. , Anderson N. J. , Bryant C. L. , Tyler J. J.
Published: September 2013

Abstract. Equatorial East Africa has a complex, regional patchwork of climate regimes, with multiple interacting drivers. Recent studies have focussed on large lakes and reveal signals that are smoothed in both space and time, and, whilst useful at a continental scale, are of less relevance when understanding short-term, abrupt or immediate impacts of climate and environmental changes. Smaller-scale studies have highlighted spatial complexity and regional heterogeneity of tropical palaeoenvironments in terms of responses to climatic forcing (e.g. the Little Ice Age [LIA]) and questions remain over the spatial extent and synchroneity of climatic changes seen in East African records. Sediment cores from paired crater lakes in western Uganda were examined to assess ecosystem response to long-term climate and environmental change as well as testing responses to multiple drivers using redundancy analysis. These archives provide annual to sub-decadal records of environmental change. The records from the two lakes demonstrate an individualistic response to external (e.g. climatic) drivers, however, some of the broader patterns observed across East Africa suggest that the lakes are indeed sensitive to climatic perturbations such as a dry Mediaeval Climate Anomaly (MCA; 1000–1200 AD) and a relatively drier climate during the main phase of the LIA (1500–1800 AD); though lake levels in western Uganda do fluctuate. The relationship of Ugandan lakes to regional climate drivers breaks down c. 1800 AD, when major changes in the ecosystems appear to be a response to sediment and nutrient influxes as a result of increasing cultural impacts within the lake catchments. The data highlight the complexity of individual lake response to climate forcing, indicating shifting drivers through time. This research also highlights the importance of using multi-lake studies within a landscape to allow for rigorous testing of climate reconstructions, forcing and ecosystem response.
Is blue intensity ready to replace maximum latewood density as a strong temperature proxy? A tree-ring case study on Scots pine from northern Sweden
Authors: Björklund J. A. , Gunnarson B. E. , Seftigen K. , Esper J. , Linderholm H. W.
Published: September 2013

Abstract. At high latitudes, where low temperatures mainly limit tree-growth, measurements of wood density (e.g. Maximum Latewood Density, MXD) using the X-Ray methodology provide a temperature proxy that is superior to that of TRW. Density measurements are however costly and time consuming and have lead to experimentation with optical flatbed scanners to produce Maximum Blue Intensity (BImax). BImax is an excellent proxy for density on annual scale but very limited in skill on centennial scale. Discolouration between samples is limiting BImax where specific brightnesses can have different densities. To overcome this, the new un-exploited parameter Δ blue intensity (ΔBI) was constructed by using the brightness in the earlywood (BIEW) as background, (BImax − BIEW = ΔBI). This parameter was tested on X-Ray material (MXD − earlywood density = ΔMXD) and showed great potential both as a quality control and as a booster of climate signals. Unfortunately since the relationship between grey scale and density is not linear, and between-sample brightness can differ tremendously for similar densities, ΔBI cannot fully match ΔMXD in skill as climate proxy on centennial scale. For ΔBI to stand alone, the range of brightness/density offset must be reduced. Further studies are needed to evaluate this possibility, and solutions might include heavier sample treatment (reflux with chemicals) or image-data treatment (digitally manipulating base-line levels of brightness).
An inter-laboratory investigation of the Arctic sea ice biomarker proxy IP25 in marine sediments: key outcomes and recommendations
Authors: Belt S. T. , Brown T. A. , Ampel L. , Cabedo-Sanz P. , Fahl K. , Kocis J. J. , Massé G. , Navarro-Rodriguez A. , Ruan J. , Xu Y.
Published: September 2013

Abstract. We describe the results of an inter-laboratory investigation into the identification and quantification of the Arctic sea ice biomarker proxy IP25 in marine sediments. 7 laboratories took part in the study, which consisted of the analysis of IP25 in a series of sediment samples from different regions of the Arctic, sub-Arctic and Antarctic, additional sediment extracts and purified standards. The results obtained allowed 4 key outcomes to be determined. First, IP25 was identified by all laboratories in sediments from the Canadian Arctic with inter-laboratory variation in IP25 concentration being substantially larger than within individual laboratories. This greater variation between laboratories was attributed to the difficulty in accurately determining instrumental response factors for IP25, despite provision of appropriate standards. Second, the identification of IP25 by 3 laboratories in sediment from SW Iceland that was believed to represent a blank, was interpreted as representing a better limit of detection or quantification for such laboratories, contamination or mis-identification. These alternatives could not be distinguished conclusively with the data available, although it is noted that the precision of these data was significantly poorer compared with the other IP25 concentration measurements. Third, 3 laboratories reported the occurrence of IP25 in a sediment sample from the Antarctic Peninsula even though this biomarker is believed to be absent from the Southern Ocean. This anomaly is attributed to a combined chromatographic and mass spectrometric interference that results from the presence of a di-unsaturated highly branched isoprenoid (HBI) pseudo-homologue of IP25 that occurs in Antarctic sediments. Finally, data are presented that suggest that extraction of IP25 is consistent between Automated Solvent Extraction (ASE) and sonication methods and that IP25 concentrations based on 7-hexylnonadecane as an internal standard are comparable using these methods. Recoveries of some more unsaturated HBIs and the internal standard 9-octylheptadecene, however, were lower with the ASE procedure, possibly due to partial degradation of these more reactive chemicals as a result of higher temperatures employed with this method. For future measurements, we recommend the use of reference sediment material with known concentration(s) of IP25 for determining and routinely monitoring instrumental response factors. Given the significance placed on the presence (or otherwise) of IP25 in marine sediments, some further recommendations pertaining to quality control are made that should also enable the two main anomalies identified here to be addressed.
THE TEMPORAL DIMENSION IN A 4D ARCHAEOLOGICAL DATA MODEL: APPLICABILITY OF THE GEOINFORMATION STANDARD
Authors: De Roo B. , Van de Weghe N. , Bourgeois J. , De Maeyer Ph.
Published: September 2013

Abstract. In recent years, the interest of many researchers in various domains is triggered to move beyond the traditional border of twodimensionality and explore the possibilities of the third and even the fourth, temporal, dimension. The emerging research interest concerning 3D and 4D and the handling of these additional dimensions can bring many benefits to archaeology as well. A 4D GIS tailored to archaeological data would facilitate better insights and more complex analyses. Its basis must be a conceptual 4D archaeological data model, which pays attention to existing data models and standards. Although in some cases more complex, archaeological data are closely related to geography and geo-information. Since the temporal dimension is a, and possibly the most, substantial element in archaeological research, this paper focusses mainly on this dimension. In this paper, the applicability of the ISO 19108 geo-information standard on temporal information for archaeological data is investigated. For a set of common temporal categories, e.g. the excavation time, the appropriate description according to this standard is determined. This will indicate in which cases the internationally recognized standard is suitable for use in an archaeological data model. Furthermore, three versions of the West European archaeological time scale as temporal ordinal reference system are constructed. For the first version, the ISO 19108 structure is used, whereas the second and third are based on geological variants. The results of the performed analysis are favourable to the usability of the ISO 19108 standard in archaeology; however, other temporal standards or data models may yield up better results.
SEMANTIC 3D CITY MODEL TO RASTER GENERALISATION FOR WATER RUN-OFF MODELLING
Authors: Verbree E. , de Vries M. , Gorte B. , Oude Elberink S. , Karimlou G.
Published: September 2013

Abstract. Water run-off modelling applied within urban areas requires an appropriate detailed surface model represented by a raster height grid. Accurate simulations at this scale level have to take into account small but important water barriers and flow channels given by the large-scale map definitions of buildings, street infrastructure, and other terrain objects. Thus, these 3D features have to be rasterised such that each cell represents the height of the object class as good as possible given the cell size limitations. Small grid cells will result in realistic run-off modelling but with unacceptable computation times; larger grid cells with averaged height values will result in less realistic run-off modelling but fast computation times. This paper introduces a height grid generalisation approach in which the surface characteristics that most influence the water run-off flow are preserved. The first step is to create a detailed surface model (1:1.000), combining high-density laser data with a detailed topographic base map. The topographic map objects are triangulated to a set of TIN-objects by taking into account the semantics of the different map object classes. These TIN objects are then rasterised to two grids with a 0.5m cell-spacing: one grid for the object class labels and the other for the TIN-interpolated height values. The next step is to generalise both raster grids to a lower resolution using a procedure that considers the class label of each cell and that of its neighbours. The results of this approach are tested and validated by water run-off model runs for different cellspaced height grids at a pilot area in Amersfoort (the Netherlands). Two national datasets were used in this study: the large scale Topographic Base map (BGT, map scale 1:1.000), and the National height model of the Netherlands AHN2 (10 points per square meter on average). Comparison between the original AHN2 height grid and the semantically enriched and then generalised height grids shows that water barriers are better preserved with the new method. This research confirms the idea that topographical information, mainly the boundary locations and object classes, can enrich the height grid for this hydrological application.
AN APPROACH TO DEVELOP 3D GEO-DBMS TOPOLOGICAL OPERATORS BY RE-USING EXISTING 2D OPERATORS
Authors: Xu D. , Zlatanova S.
Published: September 2013

Abstract. Database systems are continuously extending their capabilities to store, process and analyse 3D data. Topological relationships which describe the interaction of objects in space is one of the important spatial issues. However, spatial operators for 3D objects are still insufficient. In this paper we present the development of a new 3D topological function to distinguish intersections of 3D planar polygons. The development uses existing 2D functions in the DBMS and two geometric transformations (rotation and projection). This function is tested for a real dataset to detect overlapping 3D city objects. The paper presents the algorithms and analyses the challenges. Suggestions for improvements of the current algorithm as well as possible extensions to handle more 3D topological cases are discussed at the end.
ENHANCED LOD CONCEPTS FOR VIRTUAL 3D CITY MODELS
Authors: Benner J. , Geiger A. , Gröger G. , Häfele K.-H. , Löwner M.-O.
Published: September 2013

Abstract. Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.
REVISITING THE CONCEPT OF LEVEL OF DETAIL IN 3D CITY MODELLING
Authors: Biljecki F. , Zhao J. , Stoter J. , Ledoux H.
Published: September 2013

Abstract. This review paper discusses the concept of level of detail in 3D city modelling, and is a first step towards a foundation for a standardised definition. As an introduction, a few level of detail specifications, outlooks and approaches are given from the industry. The paper analyses the general uncertainties and shortcomings around the concept of level of detail in 3D city modelling such as ordinality and inconsistencies, and identifies factors that constitute a specific level of detail. The paper proposes a framework for a new consistent LoD definition which would consolidate present and future LoD paradigms, gives an example of an LoD specification, discusses open questions such as the contexts for which 3D city models are used in practice, and gives prospects for a future quantification and sorting of levels of detail.
TRANSFERRING MULTI-SCALE APPROACHES FROM 3D CITY MODELING TO IFC-BASED TUNNEL MODELING
Authors: Borrmann A. , Kolbe T. H. , Donaubauer A. , Steuer H. , Jubierre J. R.
Published: September 2013

Abstract. A multi-scale representation of the built environment is required to provide information with the adequate level of detail (LoD) for different use cases and objectives. This applies not only to the visualization of city and building models, but in particular to their use in the context of planning and analysis tasks. While in the field of Geographic Information Systems, the handling of multi-scale representations is well established and understood, no formal approaches for incorporating multi-scale methods exist in the field of Building Information Modeling (BIM) so far. However, these concepts are much needed to better support highly dynamic planning processes that make use of very rough information about the facility under design in the early stages and provide increasingly detailed and fine-grained information in later stages. To meet these demands, this paper presents a comprehensive concept for incorporating multi-scale representations with infrastructural building information models, with a particular focus on the representation of shield tunnels. Based on a detailed analysis of the data modeling methods used in CityGML for capturing multiscale representations and the requirements present in the context of infrastructure planning projects, we discuss potential extensions to the BIM data model Industry Foundation Classes (IFC). Particular emphasis is put on providing means for preserving the consistency of the representation across the different Levels-of-Detail (LoD). To this end we make use of a procedural geometry description which makes it possible to define explicit dependencies between geometric entities on different LoDs. The modification of an object on a coarse level consequently results in an automated update of all dependent objects on the finer levels. Finally we discuss the transformation of the IFC-based multi-scale tunnel model into a CityGML compliant tunnel representation.
Tidally induced velocity variations of the Beardmore Glacier, Antarctica, and their representation in satellite measurements of ice velocity
Authors: Marsh O. J. , Rack W. , Floricioiu D. , Golledge N. R. , Lawson W.
Published: September 2013

Abstract. Ocean tides close to the grounding line of outlet glaciers around Antarctica have been shown to directly influence ice velocity, both linearly and non-linearly. These fluctuations can be significant and have the potential to affect satellite measurements of ice discharge, which assume displacement between satellite passes to be consistent and representative of annual means. Satellite observations of horizontal velocity variation in the grounding zone are also contaminated by vertical tidal effects, the importance of which is highlighted here in speckle tracking measurements. Eight TerraSAR-X scenes from the grounding zone of the Beardmore Glacier are analysed in conjunction with GPS measurements to determine short-term and decadal trends in ice velocity. Diurnal tides produce horizontal velocity fluctuations of >50% on the ice shelf, recorded in the GPS data 4 km downstream of the grounding line. This variability decreases rapidly to <5% only 15 km upstream of the grounding line. Daily fluctuations are smoothed to <1% in the 11-day repeat pass TerraSAR-X imagery, but fortnightly variations over this period are still visible and show that satellite-velocity measurements can be affected by tides over longer periods. The measured tidal displacement observed in radar look direction over floating ice also allows the grounding line to be identified, using differential speckle tracking where phase information cannot be easily unwrapped.
Effects of gender and tie strength on Twitter interactions
Authors: Kivran-Swaine Funda , Brody Samuel , Naaman Mor
Published: September 2013

We examine the connection between language, gender, and social relationships, as manifested through communication patterns in social media. Building on an analysis of 78,000 Twitter messages exchanged between 1,753 gender-coded couples, we quantitatively study how the gender composition of conversing users influences the linguistic style apparent in the messages. Using Twitter data, we also model and control for the strength of ties between conversing users. Our findings show that, in line with existing theories, women use more intensifier adverbs, pronouns, and emoticons, especially when communicating with other women. Our results extend the understanding of gender-driven language use in the semi-public settings of social media services, and suggest implications for theory and insights for sociolinguistics.
The benefits and burdens of network diversity: Political engagement on social networking sites
Authors: Xu Weiai Wayne , Stefanone Michael A. , Rui Jian Raymond
Published: September 2013

Previous research suggests that network diversity is associated with higher levels of political engagement due to enhanced political interest. However, network diversity may also constrain political engagement because politically heterogeneous networks are comprised of others with disparate attitudes and beliefs, which may inhibit communication about politics. The results from an online survey (N = 255) suggest that network diversity affords both benefits and burdens to users in terms of online political engagement. Specifically, political diversity is positively associated with political interest, and political interest predicts political engagement on SNSs. However, political diversity in online networks is also associated with increased self-censoring behaviors. Further, relational diversity has a negative relationship with self-censoring, and this relationship is most pronounced for people with stronger self-disclosure tendencies.
Technical Efficiency of Soybean Farms and Its Determinants in Saboba and Chereponi Districts of Northern Ghana: A Stochastic Frontier Approach
Authors: Etwire Prince Maxwell , Martey Edward , Dogbe Wilson
Published: September 2013

This study analyzes the level and determinants of technical efficiency of soybean farms in the Saboba and Chereponi districts of northern Ghana. A multi-stage sampling technique was used to select 200 soybean farmers from which cross-sectional data was collected using a structured questionnaire. Data collected includes farmers’ socio-economic characteristics such as age and education as well as input and output quantities and prices. Data was analyzed using the stochastic frontier approach. Results showed a mean technical efficiency estimate of 53 percent and the return to scale was 0.75. Location of farm, participation in the Agricultural Value Chain Mentorship Project and age of farmer were found to be important in explaining technical inefficiency among soybean farmers. This implies that farmers in the short run can increase their production by 47 percent by adopting practices of the best soybean farms in Saboba and Chereponi districts of northern Ghana.
Interpolity Pottery Exchange in the Tuxtla Mountains, Southern Veracruz, Mexico
Authors: Stoner Wesley D.
Published: September 2013

Neutron activation analysis (NAA) of Coarse Orange jars demonstrates economic exchange among the Classic period political capitals of Totocapan, Matacapan, and Teotepec in the Tuxtla Mountains of southern Veracruz, Mexico. Matacapan, in particular, displays evidence of intensive pottery production at large workshops at the southern margin of the site. Comoapan (Area 411) and Area 199 present configurations of kilns, ceramic densities, and assemblage characteristics that suggest production for exchange beyond the site's boundaries. Both of these production facilities specialized in the production of Coarse Orange jars, a well-made and decorated utilitarian ceramic ware. While these products were traded to sites in the Tepango Valley, different paste recipes of the Coarse Orange type were also produced locally. Of broader concern, I examine the articulation of these regional exchange relationships with the interregional interactions previously documented among Tuxtlas groups and others in central Mexico and the Gulf Coast.
Trade and Early State Formation in the Northern Titicaca Basin, Peru
Authors: Levine Abigail , Stanish Charles , Williams P. Ryan , Chávez Cecilia , Golitko Mark
Published: September 2013

Recent theoretical work has underscored the importance of multiple strategies in the dynamic political and economic landscapes in which archaic states developed. This research emphasizes how the interaction among various non-state polities drives the growth of political centers within a region. It is in this context that numerous intermediate peer-polities emerged, and, on rare occasions in a few places around the world, it is the context of state development. War and trade have emerged as particularly important forms of strategic interaction in the theoretical literature, representing strategies of both cooperation and competition between and within complex, non-state polities. In this paper we present a detailed case study that tests and illustrates one of these theoretical propositions. We examine the role of trade in this process of social evolution as evidenced in the northern Titicaca Basin ca. 500 B.C.—A.D. 300. Based on intensive analyses of a large excavated data set, we suggest that the emergence of one regional center, called Taraco, is strongly linked to strategic participation in local and long-distance exchange networks.
The Sequence of Human Occupation in the Atacama Oases, Chile: A Radiocarbon Chronology Based on Human Skeletal Remains
Authors: Torres-Rouff Christina , Hubbe Mark
Published: September 2013

The San Pedro de Atacama oases have been permanently occupied since ca. 2500 B.P. and over this time developed a rich culture that was intertwined with social developments in the south-central Andes. However, despite decades of archaeological research, the region still lacks a strong chronological framework based on absolute dates. Here we present 53 new AMS14C dates from osteological remains from San Pedro de Atacama, in order to contribute to an understanding of the Atacameño cultural sequence. These dates suggest that some cemeteries were occupied for long periods, frequently transcending cultural phases, and that in fact a number of cemeteries within the same ayllu were in use concurrently. We also show that, not surprisingly, population displacement through time primarily follows oscillations in the sources of water. The new information presented here suggests that future work in the region should emphasize detailed analyses that consider intra-ayllu variability, given that diversity within periods is masked by the uniform use of cultural phases to describe human development.
Archaeological Residues and Recipes: Exploratory Testing for Evidence of Maize and Cacao Beverages in Postclassic Vessels from the Valley of Oaxaca, Mexico
Authors: Soleri Daniela , Winter Marcus , Bozarth Steven R. , Hurst W. Jeffrey
Published: September 2013

As dates of earliest use of Theobroma cacao in ancient Mesoamerica are established, interest is shifting to how cacao was used. One approach is to consider combinations of ingredients—the recipes for ancient cacao use. Beverages made from cacao seeds and maize have a long history in Mesoamerica. We began testing the hypothesis that there is qualitative evidence of this beverage type in the Postclassic archaeological record in a region where such a beverage, tejate, is a culturally significant food today. We looked for evidence of tejate ingredients in residue samples from eight Postclassic and one contemporary vessel from the Valley of Oaxaca, Mexico. Detection of morphologically specific maize phytoliths was accomplished by taxonomic analysis and comparison with a reference collection. Tejate ingredients Pouteria sapota and Quararibea funebris were also processed for phytolith detection. Testing for methylxanthines characteristic of Theobroma species used high-performance liquid chromatography-mass spectrometry. Four vessels were positive for maize phytoliths; three were positive for theobromine; two were positive for both maize and cacao. No diagnostic phytoliths were identified for the other tejate ingredients. Our hypothesis was supported; still, many challenges are present in the search for a deeper understanding of ancient cacao usage in this region of Mesoamerica.
Le contrôle de gestion dans les PME
Authors: Condor Roland
Published: September 2013

La recherche sur le contrôle de gestion dans les PME a connu un fort développement depuis 2000. Mais alors que des travaux ont développé une approche par le cycle de vie (orientant leurs recherches sur les firmes en démarrage ou en début de croissance), peu de travaux francophones ont repris cette approche. Ce papier restitue ainsi une synthèse des recherches sur le contrôle de gestion dans les PME intégrant une approche par la taille et une approche par le cycle de vie. Nous concluons sur le fait qu’il y a beaucoup d’opportunités pour les chercheurs qui souhaitent étudier le contrôle de gestion dans les PME. L’approche par la taille peut encore être poursuivie tandis que la vision par le cycle de vie devrait être davantage mobilisée.
Modern Multispectral Sensors Help Track Explosive Eruptions
Authors: Harris A. J. L. , Valade S. , Sawyer G. M. , Donnadieu F. , Battaglia J. , Gurioli L. , Kelfoun K. , Labazuy P. , Stachowicz T. , Bombrun M. , Barra V. , Delle Donne D. , Lacanna G.
Published: September 2013

Due to its massive air traffic impact, the 2010 eruption of Eyjafjallajökull was felt by millions of people and cost airlines more than U.S. $1.7 billion. The event has, thus, become widely cited in renewed efforts to improve real‐time tracking of volcanic plumes, as witnessed by special sections published last year in Journal of Geophysical Research, (117, issues D20 and B9).
Downscaled Climate Projections Suitable for Resource Management
Authors: Thrasher Bridget , Xiong Jun , Wang Weile , Melton Forrest , Michaelis Andrew , Nemani Ramakrishna
Published: September 2013

The general circulation model (GCM) experiments conducted under the Coupled Model Intercomparison Project Phase 5 (CMIP5) [Taylor et al., 2012], which is being conducted in preparation for the Intergovernmental Panel on Climate Change's Fifth Assessment Report, provide fundamental data sets for assessing the effects of global climate change. However, efforts to assess regional or local effects of the projected changes in climate are often impeded by the coarse spatial resolution of the GCM outputs, as well as potential local or regional biases in GCM outputs [Fowler et al., 2007].
Hurricane Sandy caused extreme erosion of New York beaches
Authors: Balcerak Ernie
Published: September 2013

Beaches on Fire Island, New York, lost more than half of their sand as a result of Hurricane Sandy, according to a new report by the U.S. Geological Survey (USGS). Fire Island is one of the barrier islands along the south shore of Long Island, N. Y. The finding, released 27 August, involved field surveys conducted before and after the storm. In addition, the researchers used lidar and aerial photography to evaluate changes to the beaches and shoreline and determined the volume and distribution of overwash deposits that were carried to the island's interior following the storm.
NOAA and EUMETSAT agree to continued cooperation
Authors: Balcerak Ernie
Published: September 2013

The National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) have agreed to continue their long‐term cooperation on satellite‐based weather monitoring. NOAA acting administrator Kathryn Sullivan and EUMETSAT director general Alain Ratier signed the agreement at a ceremony at the European Union Delegation in Washington, D. C., on 27 August.
Properties of coastally trapped waves around Australia
Authors: Balcerak Ernie
Published: September 2013

Coastally trapped waves, which are generated by alongshore wind and propagate along a coastline, are common around Australia's southern coast. Some details of the propagation of coastally trapped waves are still uncertain, partly because of the relatively coarse resolution of tide gauge observations as well as the complex ocean bottom surface over which the waves propagate. There has been some debate on the mechanism by which these waves propagate from the southern to eastern coasts of Australia.
Highly Efficient Infrared Quantum Cutting in Tb3+−Yb3+ Codoped Silicon Oxynitride for Solar Cell Applications
Authors: An Yong‐Tao , Labbé Christophe , Cardin Julien , Morales Magali , Gourbilleau Fabrice
Published: September 2013

A high efficiency infrared quantum cutting effect in a Tb3+–Yb3+ codoped silicon oxynitride system is demonstrated. The thin films are deposited on Si substrates by reactive magnetron co‐sputtering of a Si target topped with Tb4O7 and Yb2O3 chips under pure nitrogen plasma. The photoluminescence dynamics are investigated, revealing a quantum efficiency of this system at 980 nm up to 197% for the higher Yb3+ concentration. Thus, via a cooperative transfer mechanism between Tb3+ and Yb3+, an absorbed UV–visible photon gives rise to almost two emitted IR photons. Such a down‐conversion effect is demonstrated upon indirect excitation of energy donors, via defect states in the host matrix. These down‐converter films could be directly and easily integrated on top of the Si‐based solar cell to improve the photoelectric conversion efficiency at a lower cost. An evaluation of the additional external quantum efficiency is deduced from this optical system and found to be almost 2%.
Peripheral input and its importance for central sensitization
Authors: Baron Ralf , Hans Guy , Dickenson Anthony H.
Published: September 2013

Many pain states begin with damage to tissue and/or nerves in the periphery, leading to enhanced transmitter release within the spinal cord and central sensitization. Manifestations of this central sensitization are windup and long‐term potentiation. Hyperexcitable spinal neurons show reduced thresholds, greater evoked responses, increased receptive field sizes, and ongoing stimulus‐independent activity; these changes probably underlie the allodynia, hyperalgesia, and spontaneous pain seen in patients. Central sensitization is maintained by continuing input from the periphery, but also modulated by descending controls, both inhibitory and facilitatory, from the midbrain and brainstem. The projections of sensitized spinal neurons to the brain, in turn, alter the processing of painful messages by higher centers. Several mechanisms contribute to central sensitization. Repetitive activation of primary afferent C fibers leads to a synaptic strengthening of nociceptive transmission. It may also induce facilitation of non‐nociceptive Aβ fibers and nociceptive Aδ fibers, giving rise to dynamic mechanical allodynia and mechanical hyperalgesia. In postherpetic neuralgia and complex regional pain syndrome, for example, these symptoms are maintained and modulated by peripheral nociceptive input. Diagnosing central sensitization can be particularly difficult. In addition to the medical history, quantitative sensory testing and functional magnetic resonance imaging may be useful, but diagnostic criteria that include both subjective and objective measures of central augmentation are needed. Mounting evidence indicates that treatment strategies that desensitize the peripheral and central nervous systems are required. These should generally involve a multimodal approach, so that therapies may target the peripheral drivers of central sensitization and/or the central consequences. Ann Neurol 2013;74:630–636
Effective binuclear Pd(II) complexes for Suzuki reactions in water
Authors: Hanhan Murat Emre , Cetinkaya Cemil , Shaver Michael P.
Published: September 2013

A series of new ionic binuclear Pd(II) complexes supported by water‐soluble bis(α‐diimine) ligands were prepared and employed as catalysts for the palladium‐catalyzed Suzuki reaction in aqueous media. The binuclear nature of the complexes increased the reaction rate, while electronic and steric modification of the ligand frameworks had a remarkable influence upon the catalytic activity of the palladium complexes. The catalysts were shown to be homogeneous through mercury poisoning experiments and complexes could be recycled more than 10 times without loss of catalytic activity. Copyright © 2013 John Wiley & Sons, Ltd.
Copper‐catalyzed highly efficient aerobic oxidative synthesis of benzimidazoles, benzoxazoles and benzothiazoles from aromatic alcohols under solvent‐free conditions in open air at room temperature
Authors: Yu Jiatao , Xu Jian , Lu Ming
Published: September 2013

Solvent‐free oxidative synthesis of benzimidazoles, benzoxazoles and benzothiazoles from aromatic alcohols and o‐phenylenediamine, o‐aminophenol and o‐aminothiophenol has been achieved by using CuCl, 2,2′‐bipyridine and TEMPO (2,2,6,6‐tetramethylpiperidine‐1‐oxyl). The reaction proceeds via a dehydrogenation in open air at room temperature, and a wide variety of derivatives were obtained in good to excellent yields. The reaction mechanism was proposed and this method provides a mild and efficient access to substituted benzimidazoles, benzoxazoles and benzothiazoles. Copyright © 2013 John Wiley & Sons, Ltd.
Biochemist‐tree: Using modular origami to understand the integration of intermediary metabolism
Authors: Sharp Duncan
Published: September 2013

Intermediary metabolism can be a complex area to study due to the inherent modularity of the catabolic biochemical processes. This article outlines a novel, cost‐effective, and universally applicable teaching activity to enhance students understanding of the inter‐relationship between the key processes of intermediary metabolism. A simple origami model, the “Biochemist‐Tree” has been developed as a learning activity for intermediary metabolism, and its implementation was assessed. This modular origami model involves folding individual layers of the model, which must then be constructed into a “tree” with the metabolic process flowing correctly from macromolecules to ATP production from the electron transport chain/oxidative phosphorylation. Forty‐eight students were provided with the activity as a revision tutorial exercise toward the end of a module on the introduction to biochemistry. The findings from this study show that the students found the activity to be interesting (>75%), scientifically useful (95%), and would recommend other students (85%) using this for their revision of catabolic metabolism. The novel nature of the exercise meant that it was engaging for the students and one that they also felt improved the understanding of the integration of the metabolic processes included. Further to being a one‐off test of student understanding, the inclusion of key molecular structures and pathway steps helps to further embed these as a reference sources for revision. © 2013 by The International Union of Biochemistry and Molecular Biology, 41(5):309–314, 2013
Resident's morning report: An opportunity to reinforce principles of biomedical science in a clinical context
Authors: Brass Eric P.
Published: September 2013

The principles of biochemistry are core to understanding cellular and tissue function, as well as the pathophysiology of disease. However, the clinical utility of biochemical principles is often obscure to clinical trainees. Resident's Morning Report is a common teaching conference in which residents present clinical cases of interest to a faculty member for discussion. This venue provides an opportunity to illustrate how basic biomedical principles facilitate an understanding of the clinical presentation, the relevant pathophysiology, and the rationale for diagnostic and therapeutic strategies. A discussion of biochemical principles can easily be incorporated into these case discussions, with the potential to reinforce these concepts and to illustrate their application to clinical decision making. This approach maintains the effort to teach basic biomedical sciences in the context of clinical application across the educational continuum. © 2013 by The International Union of Biochemistry and Molecular Biology, 41(5):315–318, 2013
Students' understanding of primary and secondary protein structure: Drawing secondary protein structure reveals student understanding better than simple recognition of structures
Authors: Harle Marissa , Towns Marcy H.
Published: September 2013

The interdisciplinary nature of biochemistry courses requires students to use both chemistry and biology knowledge to understand biochemical concepts. Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations in addition to a fragmented understanding of fundamental biochemistry concepts. This project focuses on students' understanding of primary and secondary protein structure and drawings (representations) of hydrogen‐bonding in alpha helices and beta sheets. Analysis demonstrated that students can recognize and identify primary protein structure concepts when given a polypeptide. However, when asked to draw alpha helices and beta sheets and explain the role of hydrogen bonding their drawings students exhibited a fragmented understanding that lacked coherence. Faculty are encouraged to have students draw molecular level representations to make their mental models more explicit, complete, and coherent. This is in contrast to recognition and identification tasks, which do not adequately probe mental models and molecular level understanding. © 2013 by The International Union of Biochemistry and Molecular Biology 41(6):369–376, 2013