bluuebunny/crossref_metadata_2025 huggingface dataset:
Jacobian discrepancies and rational singularities
Authors: de Fernex Tommaso , Docampo Roi
Published: December 2013

Inspired by several works on jet schemes and motivic integration, we consider an extension to singular varieties of the classical definition of discrepancy for morphisms of smooth varieties. The resulting invariant, which we call

{Jacobian \: discrepancy}

, is closely related to the jet schemes and the Nash blow-up of the variety. This notion leads to a framework in which adjunction and inversion of adjunction hold in full generality, and several consequences are drawn from these properties. The main result of the paper is a formula measuring the gap between the dualizing sheaf and the Grauert–Riemenschneider canonical sheaf of a normal variety. As an application, we give characterizations for rational and Du Bois singularities on normal Cohen–Macaulay varieties in terms of Jacobian discrepancies. In the case when the canonical class of the variety is

\mathbb Q

-Cartier, our result provides the necessary corrections for the converses to hold in theorems of Elkik, of Kovács, Schwede and Smith, and of Kollár and Kovács on rational and Du Bois singularities.
Higher Homotopy Commutativity of $H$-spaces and the Cyclohedra
Authors: Kawamoto Yusuke
Published: December 2013

We define a higher homotopy commutativity of

H

-spaces using the cyclohedra

\{W_n\}_{n\ge 1}

constructed by Bott and Taubes. An

H

-space whose multiplication is homotopy commutative of the

n

-th order is called a

B_n

-space. We also give combinatorial decompositions of the permuto-associahedra

\{KP_n\}_{n\ge 1}

introduced by Kapranov into union of product spaces of the cyclohedra. From the decomposition, we have a relation between the

B_n

-structures and another higher homotopy commutativity represented by the permuto-associahedra.
Equatorial spread F studies using SAMI3 with two-dimensional and three-dimensional electrostatics
Authors: Aveiro H. C. , Huba J. D.
Published: December 2013

Abstract. This letter presents a study of equatorial F region irregularities using the NRL SAMI3/ESF model, comparing results using a two-dimensional (2-D) and a three-dimensional (3-D) electrostatic potential solution. For the 3-D potential solution, two cases are considered for parallel plasma transport: (1) transport based on the parallel ambipolar field, and (2) transport based on the parallel electric field. The results show that the growth rate of the generalized Rayleigh–Taylor instability is not affected by the choice of the potential solution. However, differences are observed in the structures of the irregularities between the 2-D and 3-D solutions. Additionally, the plasma velocity along the geomagnetic field computed using the full 3-D solution shows complex structures that are not captured by the simplified model. This points out that only the full 3-D model is able to fully capture the complex physics of the equatorial F region.
A simple explanation for the sensitivity of the hydrologic cycle to surface temperature and solar radiation and its implications for global climate change
Authors: Kleidon A. , Renner M.
Published: December 2013

Abstract. The global hydrologic cycle is likely to increase in strength with global warming, although some studies indicate that warming due to solar absorption may result in a different sensitivity than warming due to an elevated greenhouse effect. Here we show that these sensitivities of the hydrologic cycle can be derived analytically from an extremely simple surface energy balance model that is constrained by the assumption that vertical convective exchange within the atmosphere operates at the thermodynamic limit of maximum power. Using current climatic mean conditions, this model predicts a sensitivity of the hydrologic cycle of 2.2% K−1 to greenhouse-induced surface warming which is the sensitivity reported from climate models. The sensitivity to solar-induced warming includes an additional term, which increases the total sensitivity to 3.2% K−1. These sensitivities are explained by shifts in the turbulent fluxes in the case of greenhouse-induced warming, which is proportional to the change in slope of the saturation vapor pressure, and in terms of an additional increase in turbulent fluxes in the case of solar radiation-induced warming. We illustrate an implication of this explanation for geoengineering, which aims to undo surface temperature differences by solar radiation management. Our results show that when such an intervention compensates surface warming, it cannot simultaneously compensate the changes in hydrologic cycling because of the differences in sensitivities for solar vs. greenhouse-induced surface warming. We conclude that the sensitivity of the hydrologic cycle to surface temperature can be understood and predicted with very simple physical considerations but this needs to reflect on the different roles that solar and terrestrial radiation play in forcing the hydrologic cycle.
A novel model evaluation approach focussing on local and advected contributions to urban PM2.5 levels – application to Paris, France
Authors: Petetin H. , Beekmann M. , Sciare J. , Bressi M. , Rosso A. , Sanchez O. , Ghersi V.
Published: December 2013

Abstract. Aerosol simulations in chemistry transport models (CTMs) still suffer from numerous uncertainties, and diagnostic evaluations are required to point out major error sources. This paper presents an original approach to evaluate CTMs based on local and imported contributions in a large megacity rather than urban background concentrations. The study is applied to the CHIMERE model in the Paris region (France) and considers the fine particulate matter (PM2.5) and its main chemical constituents (elemental and organic carbon, nitrate, sulfate and ammonium), for which daily measurements are available during a whole year at various stations (PARTICULES project). Back-trajectory data are used to locate the upwind station, from which the concentration is identified as the import, the local production being deduced from the urban concentration by subtraction. Uncertainties on these contributions are quantified. Small biases in urban background PM2.5 simulations (bias of +16%) hide significant error compensations between local and advected contributions, as well as in PM2.5 chemical compounds. In particular, wintertime OM imports appear strongly underestimated while local OM and EC production are overestimated all along the year. Erroneous continental woodburning emissions and missing SOA pathways may explain errors on advected OM, while carbonaceous compounds overestimation is likely to be related to errors in emissions and dynamics. A statistically significant local formation of nitrate is also highlighted from observations, but missed by the model. Together with the overestimation of nitrate imports, it leads to a bias of +51% on the local PM2.5 contribution. Such an evaluation finally gives more detailed insights on major gaps in current CTMs on which future efforts are needed.
An improved non-iterative surface layer flux scheme for atmospheric stable stratification condition
Authors: Li Y. , Gao Z. , Li D. , Wang L. , Wang H.
Published: December 2013

Abstract. Parameterization of turbulent fluxes under stably stratified conditions has always been a challenge. Current surface fluxes calculation schemes either need iterations or suffer low accuracy. In this paper, a non-iteration scheme is proposed to approach the classic iterative computation results using multiple regressions. It can be applied to the full range of roughness status 10 ≤ z/z0 ≤ 105 and −0.5 ≤ log(z0/z0h) ≤ 30 under stable conditions 0< RiB ≤ 2.5. The maximum (average) relative errors for the turbulent transfer coefficients for momentum and sensible heat are 12% (1%) and 9% (1%), respectively.
Using expert knowledge to increase realism in environmental system models can dramatically reduce the need for calibration
Authors: Gharari S. , Hrachowitz M. , Fenicia F. , Gao H. , Savenije H. H. G.
Published: December 2013

Abstract. Conceptual environmental systems models, such as rainfall runoff models, generally rely on calibration for parameter identification. Increasing complexity of this type of model for better representation of hydrological process heterogeneity typically makes parameter identification more difficult. Although various, potentially valuable, strategies for better parameter identification were developed in the past, strategies to impose general conceptual understanding regarding how a catchment works into the process of parameterizing a conceptual model has still not been fully explored. In this study we assess the effect of imposing semi-quantitative, relational expert knowledge into the model development and parameter selection, efficiently exploiting the complexity of a semi-distributed model formulation. Making use of a topography driven rainfall-runoff modeling (FLEX-TOPO) approach, a catchment was delineated into three functional units, i.e. wetland, hillslope and plateau. Ranging from simplicity to complexity, three model set-ups, FLEXA, FLEXB and FLEXC have been developed based on these functional units. While FLEXA is a lumped representation of the study catchment, the semi-distributed formulations FLEXB and FLEXC introduce increasingly more complexity by distinguishing 2 and 3 functional units, respectively. In spite of increased complexity, FLEXB and FLEXC allow modelers to compare parameters as well as states and fluxes of their different functional units to each other. Based on these comparisons, expert knowledge based, semi-quantitative relational constraints have been imposed on three models structures. More complexity of models allows more imposed constraints. It was shown that a constrained but uncalibrated semi-distributed model, FLEXC, can predict runoff with similar performance than a calibrated lumped model, FLEXA. In addition, when constrained and calibrated, the semi-distributed model FLEXC exhibits not only higher performance but also reduced uncertainty for prediction, compared to the calibrated, lumped FLEXA model.
Application and prospect of high-resolution remote sensing and geo-information system in estimating earthquake casualties
Authors: Feng T. , Hong Z. , Fu Q. , Ma S. , Jie X. , Wu H. , Jiang C. , Tong X.
Published: December 2013

Abstract. An accurate estimation of the number of casualties can help respond earthquake disaster and increase the number of survivors. Building damage is considered as the major cause of earthquake casualties in many developing countries. The high-resolution satellite imagery (HRSI) can be used to detect the damage of buildings in a short time. This advantage provides the possibility to estimate the earthquake casualties immediately after earthquake. With respect to capability of HRSI, this paper builds a new model for estimating the casualty number in an earthquake disaster based on the attributes and damage of buildings. Three groups of earthquake data, 2003 Bam earthquake, 2008 Wenchuan earthquake and 2010 Yushu earthquake, were used to evaluate our proposed model. The estimating results indicate that the model has improved the accuracy significantly. Meanwhile, the parameters in model should be different from earthquake between developed and developing countries. This study can provide valuable information to help develop an efficient rescue operation.
Atlantic meridional ocean heat transport at 26° N: impact on subtropical ocean heat content variability
Authors: Sonnewald M. , Hirschi J. J.-M. , Marsh R. , McDonagh E. L. , King B. A.
Published: December 2013

Abstract. Local climate is significantly affected by changes in the oceanic heat content on a range of timescales. This variability is driven by heat fluxes from both the atmosphere and the ocean. In the Atlantic the meridional overturning circulation is the main contributor to the oceanic meridional heat transport for latitudes south of about 50° N. The RAPID project has been successfully monitoring the Atlantic meridional overturning at 26° N since 2004. This study demonstrates how these data can be used to estimate the variability of the basin-wide ocean heat content in the upper 800 m between 26° and 36° N. Traditionally the atmosphere is seen to dominate the ocean heat content variability. However, previous studies have looked at smaller areas in the Gulf Stream region, finding that the ocean dominates deseasoned fluctuations of ocean heat content, while studies of the whole North Atlantic region suggest that the atmosphere may be dominant. In our study we use a box model to investigate fluctuations of the ocean heat content in the subtropical North Atlantic between 26° and 36° N. The box model approach is validated using 19 yr of high-resolution general circulation model (GCM) data. We find that in both the GCM- and RAPID-based data the ocean heat transport dominates the deseasoned heat content variability, while the atmosphere's impact on the ocean heat content evolution stabilizes after 6 months. We demonstrate that the utility of the RAPID data goes beyond monitoring the overturning circulation at 26° N, and that it can be used to better understand the causes of ocean heat content variability in the North Atlantic. We illustrate this for a recent decrease in ocean heat content which was observed in the North Atlantic in 2009 and 2010. Our results suggest that most of this ocean heat content reduction can be explained by a reduction of the meridional ocean heat transport during this period.
The Rhetorical Unconscious of Argumentation Theory:
Authors: Crosswhite James
Published: December 2013

The contemporary study of argumentation has produced sophisticated new theories that attempt to capture norms for evaluating arguments that are much more complex and more suited to actual argumentation than the traditional logical standards. The most prominent theories also make explicit attempts to distinguish themselves from rhetorical approaches. Yet, in the case of at least three major systematic theories of argumentation, a reliance on rhetorical theory persists. Despite denials, each account ultimately grounds its norms in considerations of reception and audience. There are good reasons why these theories are attracted to rhetoric, and there are understandable factors that produce their concern about it. Ultimately, though, the rhetorical dimension of these theories is one of their major theoretical virtues and a clear sign of their staying close to the realities of argumentation.
Rhetoric, Cogency, and the Radically Social Character of Persuasion:
Authors: Rehg William
Published: December 2013

This article examines Jürgen Habermas's argumentation theory for an answer to the question of the role of rhetoric in cogent argument-making practices. At first glance, Habermas's triadic synthesis of logic, dialectic, and rhetoric appears conventionally neo-Aristotelian and logocentric. However, in aligning rhetoric with a formal, idealized understanding of argument as a process, Habermas gives rhetorical evaluation an authoritative role in certifying nonrelativistic public knowledge. Further elaboration of the implications of his model reveals a radically social view of rational persuasion and of reasonable opinion formation that makes intellectual humility a central virtue. Humility heavily restricts the scope for reasonable disagreement and dissent, particularly in polarized controversies. Examination of such a controversy shows the limits of the Habermasian conception of rhetoric.
The Role of Audience in Argumentation from the Perspective of Informal Logic
Authors: Johnson Ralph H.
Published: December 2013

There is something importantly right about an audience-centered approach to argumentation, but it raises questions. For example, when it is said that the argumentation is a function of the audience addressed, what does “audience” mean here? Who constitutes this audience? More important, how does the arguer gain this knowledge of this audience? And is acceptance by the audience really the best way to view the goal of argumentation? This article broaches these questions, turning to discussions of audience by Chaïm Perelman, Christopher Tindale, and Trudy Govier to ask how one comes to know one's audience and whether acceptance by the audience is the goal of argumentation.
Are Northern Practices for Supporting Entrepreneurs Transferable to the South?
Authors: Tremblay Maripier , Brière Sophie , Daou Alain , Baillargeon Guillaume
Published: December 2013

The authors explore the question of model transferability from North to South through a case study of a Canadian non-governmental organization (NGO) which supports entrepreneurs in South Africa. The analysis shows that the transfer to the South of an entrepreneurial support model developed in the North has significant limitations because of country specificities. It becomes apparent that adaptations are necessary to ensure the adequacy of the model in the particular context of the targeted country. Success factors and adaptation strategies were identified based on the limitations to transferability. These limitations relate to consideration of the local business sectors, consideration of lenders' and stakeholders' expectations, establishing partnerships with local players, internal capacity building, segmentation of services according to entrepreneur types, activities targeted at entrepreneur service customization and, finally, the use of quantitative and qualitative indicators and the balance between expansion and consolidation of the organization.
Can Personal Initiative Training Improve Small Business Success?
Authors: Solomon Goosain , Frese Michael , Friedrich Christian , Glaub Matthias
Published: December 2013

High levels of personal initiative will be required to unlock the potential offered by the many untapped resources in Africa in terms of business opportunities. Significant resources are ploughed into the development of the small business sector by governments in Africa, particularly in South Africa. However, there is little evidence that these efforts are sufficiently effective to produce the desired results. Two issues are addressed in this article: (a) whether or not enhancing the personal initiative of owner-managers improves the performance of small businesses, and (b) the moderation of the content and effectiveness of a short training intervention by means of a longitudinal evaluation study, including a control group. The findings show an increase in the training group's business activities and performance, and also identify the varied contributions of the components of the training.
Innovation Failure: Losing Sight of the Big Picture
Authors: Obermöller Anna Fortoul
Published: December 2013

The Case Study section of the International Journal of Entrepreneurship and Innovation serves two purposes. First, the case studies presented are concerned with problematical issues that are pertinent to students of entrepreneurship. Thus they constitute appropriate teaching and learning vehicles on a variety of postgraduate and undergraduate programmes. Each case study is accompanied by a set of guidelines for the use of tutors. Second, it is envisaged that those engaged in entrepreneurial activities will find the cases both interesting and useful.

The case of PSA Peugeot Citroën's electric passenger car is an example of an innovation perceived as a failure because of its disappointing sales volume. Yet, by limiting our assessment of the electric passenger car to a short-term perspective, we may miss out on an essential part of its value. As part of a wider innovation process, the electric passenger car project is a significant step for PSA in its expertise regarding electric vehicles.

Key learning outcomes: (a) to understand that innovation is a complex process with fuzzy frontiers, both in time and space; (b) to understand that innovation is a long-term investment with spillovers into other projects; (c) to be aware of the multiple perspectives that may be adopted when examining innovation; and (d) to be aware of the impact of labelling a project a failure.
Africa's Entrepreneurial Community
Authors: Conway Clifford
Published: December 2013

’Internet Review’ provides critical commentary on entrepreneurship, small business and innovation information on the Web.
A Stylized Applied Energy-Economy Model for France
Authors: Henriet Fanny , Maggiar Nicolas , Schubert Katheline
Published: December 2013

We build, calibrate and simulate a stylized energy-economy model designed to evaluate the magnitude of carbon tax that would allow the French economy to reduce by a factor of four its CO2 emissions at a forty-year horizon. We estimate the substitution possibilities between fossil energy and other factors for households and firms. We build two versions of the model, the first with exogenous technical progress, and the second with an endogenization of the direction of technical progress. We show that if the energy-saving technical progress rate remains at its recent historical value, the magnitude of the carbon tax is quite unrealistic. When the direction of technical progress responds endogenously to economic incentives, CO2 emissions can be reduced by more than that allowed by the substitution possibilities, but not by a factor of four. To achieve this, an additional instrument is needed, namely a subsidy to fossil energy-saving research. The redirection of technical progress, which is a driver of energy transition, comes at a small cost in terms of the overall growth rate of the economy. Keywords: CGE model, Energy, Environment, Carbon tax
Urban water‐cycle energy use and greenhouse gas emissions
Authors: Oppenheimer Joan , Badruzzaman Mohammad , McGuckin Robyn , Jacangelo Joseph G.
Published: December 2013

The water–energy nexus has motivated water industry professionals to maintain water performance goals with less energy input and fewer greenhouse gas (GHG) emissions. This article investigates protocols, methodologies, and tools for energy and GHG emissions control and tracking that are adaptable to or specifically developed for use within the urban water cycle. Although many operational energy‐minimization strategies are available, real‐time or near real‐time tools for monitoring and reporting of energy use and GHG emissions are not yet widely developed for the water sector. Additional study is warranted to obtain a better understanding of process‐specific emission factors and real‐time measurement and control of activity levels associated with emissions. It may also be beneficial for the water industry to consider a continually updated compendium of GHG emission‐estimation methodologies.
Local Transplantation of Granulocyte Colony Stimulating Factor-Mobilized CD34+ Cells for Patients With Femoral and Tibial Nonunion: Pilot Clinical Trial
Authors: Kuroda Ryosuke , Matsumoto Tomoyuki , Niikura Takahiro , Kawakami Yohei , Fukui Tomoaki , Lee Sang Yang , Mifune Yutaka , Kawamata Shin , Fukushima Masanori , Asahara Takayuki , Kawamoto Atsuhiko , Kurosaka Masahiro
Published: December 2013

Most bone fractures typically heal, although a significant proportion (5%–10%) of fractures fail to heal, resulting in delayed union or persistent nonunion. Some preclinical evidence shows the therapeutic potential of peripheral blood CD34+ cells, a hematopoietic/endothelial progenitor cell-enriched population, for bone fracture healing; however, clinical outcome following transplantation of CD34+ cells in patients with fracture has never been reported. We report a phase I/IIa clinical trial regarding transplantation of autologous, granulocyte colony stimulating factor-mobilized CD34+ cells with atelocollagen scaffold for patients with femoral or tibial fracture nonunion (n = 7). The primary endpoint of this study is radiological fracture healing (union) by evaluating anteroposterior and lateral views at week 12 following cell therapy. For the safety evaluation, incidence, severity, and outcome of all adverse events were recorded. Radiological fracture healing at week 12 was achieved in five of seven cases (71.4%), which was greater than the threshold (18.1%) predefined by the historical outcome of the standard of care. The interval between cell transplantation and union, the secondary endpoint, was 12.6 ± 5.4 weeks (range, 8–24 weeks) for clinical healing and 16.1 ± 10.2 weeks (range, 8–36 weeks) for radiological healing. Neither deaths nor life-threatening adverse events were observed during the 1-year follow-up after the cell therapy. These results suggest feasibility, safety, and potential effectiveness of CD34+ cell therapy in patients with nonunion.
Usage of Saliva as Alternative Biological Fluid to Serum for Minerals, Energetic and Hormones Assessment in Lactating Egyptian Water Buffaloes
Authors: Hefnawy Abdelghany , Shousha Saad , Abdelhamid Omnia , Youssef Seham
Published: December 2013

Blood sample is the most common biological fluid utilized for diagnosis and monitoring of diseases. Saliva contains locally produced substances as well as serum component, so the aim of this study is to compare the profile of minerals, energetic and hormones in Egyptian water buffaloes. Blood serum and saliva samples were collected from 80 healthy multiparous, non- pregnant lactating Egyptian water buffaloes. Both fluids were tested for sodium, potassium, chloride, calcium, phosphorous, magnesium, insulin, cortisol, ACTH, glucose, urea, creatinine, total protein and immunoglobulin [IgA]. The results revealed that, serum concentrations of calcium, glucose, total protein, sodium, chloride, Insulin, cortisol, ACTH and IgA were significantly higher than saliva. In contrast, the concentrations of potassium and phosphorous in the saliva were significantly higher than that of serum. On the other hand no significant change in respect of urea, creatinine and magnesium was noted between saliva and serum. The relationships between saliva and serum of the estimated parameters were significantly positive except the concentrations of insulin in saliva and blood serum did not correlate. In conclusion, the saliva sample can be used in clinical practice with high level of reliability and provide non-invasive biological fluid for monitoring of different parameters in Egyptian water buffaloes.
Buffalo Sensory Analysis of Meat in the City of Medellin, Colombia, South America
Authors: Hurtado-Lugo Naudin , Goes Tulio , Bedoya Mario , Restrepo Luis F. , Tonhati Humberto
Published: December 2013

The aim of this study was to determine the organoleptic properties of meat buffaloes in the town of Medellin, Colombia. It was a methodology employed with satisfaction hedonic scale of five-point verbal. GLM method was employed, with the technical MANOVA, with the orthogonal contrasts canonical, determining the dimensionality, in that the response variables were expressed by the criterion of maximum likelihood. The analysis was complemented through the technique of Spearman, using the SAS statistical package version 9.0. In making, the MANOVA, for the response variables smell, taste, tact and general appearance of the product found no statistical differences (p> 0.05). However, the variables above presented statistical relationship (p <0.05), when the ANOVA analysis for each gender. The Spearman correlation coefficient showed that there are significant correlations between the different responses, for both men and women. This result indicates that the meat buffaloes, will present a good acceptance by the general public and therefore an acceptable marketing in the city of Medellin
A Comparative Study on the Physicochemical Parameters of Camel and Buffalo Milk
Authors: Singh Sajjan , Poonia Rakesh Kumar , Singh Raghvendar , Mehta S.C. , Patil N.V.
Published: December 2013

This research work was carried out to compare the various physicochemical parameters of two species, camel and buffalo. Camel milk samples were collected at National Research Centre on Camel, Bikaner and buffaloes milk samples were collected from the surroundings villages of Bikaner. After collection milk samples were brought to the laboratory of NRCC Bikaner and they were analyzed for fat, SNF (Solid Not Fat), protein, lactose, total ash and pH using milk analyzer (Lactoscan). Camel milk had 2.71±0.11 fat, 6.91±0.03 SNF, 2.23±0.02 protein, 3.86±0.02 lactose, 0.79±0.004 total ash and 6.95±0.01 pH while buffalo milk had 8.71±0.82 fat, 8.44±0.19 SNF, 4.11±0.02 protein, 4.46±0.15 lactose, 0.98±0.05 total ash and 7.59±0.02 pH. Fat, SNF, protein and pH of buffalo milk was significantly (P<0.001) higher than camel milk. Lactose and total ash in buffalo milk was also higher than camel milk but at P<0.05 level. So it can be concluded that all the studied parameters were high in buffalo milk than camel milk
The Consumers Characteristics Analysis of Low Temperature Home Delivery
Authors: Lai Shu-Fang
Published: December 2013

Because of technological advancements and the popularity of the Internet, online shopping has become an important shopping channel for consumers. Because people increasingly eat out, more consumers shop online, and food products are collected from convenience stores, or frozen food home delivery services are used. This study used questionnaire surveys to analyze the consumption habits of residents who shop online for frozen foods in the urban areas of northern Taiwan (Taipei City and New Taipei City). We distributed and collected 548 questionnaires, of which 484 were valid. Descriptive statistics, a chi-square test, and logistics regression analysis were used to analyze consumer characteristics, as well as important influential factors. The research results indicated that most online shoppers were women, and the top 3 factors influencing their purchasing decisions were freshness, delivery convenience, and ordering convenience. Participants in the age group of 40-49 years old, living in the urban area of New Taipei City, without junior college education, and with less than 10,000 NTD monthly incomes, were less likely to purchase frozen foods using low-temperature logistics services.
Knowing the unknowns
Authors: Seitz Russell
Published: December 2013

The Earth's atmosphere is not the only source of radiative forcing and anthropogenic climate change. As surely as people and civilizations have carbon footprints, they have albedo footprints as well. By altering the reflectivity of roughly half the land surface of the Earth in the past, mankind has made inadvertent geoengineering a part of the landscape of history. This worldwide alteration of reflectivity raises questions about the future of climate change, for albedo is a first‐order determinant of the Earth's radiative equilibrium. As surfaces absorb roughly 100 times more solar energy than the CO2 in the atmosphere, future anthropogenic changes in both land and water albedo may figure significantly in climate policy outcomes.
Orthogonal relation between wavefield polarization and fast S wave direction in the Val d'Agri region: An integrating method to investigate rock anisotropy
Authors: Pischiutta M. , Pastori M. , Improta L. , Salvini F. , Rovelli A.
Published: December 2013

Wavefield polarization is investigated using 200 seismograms recorded by a network of 20 stations installed on rock outcrops in the Val d'Agri region that hosts the largest oil fields in the southern Apennines (Italy). Polarization is assessed both in the frequency and time domains through the individual‐station horizontal‐to‐vertical spectral ratio and covariance‐matrix analysis, respectively. We find that most of the stations show a persistent horizontal polarization of waveforms, with a NE‐SW predominant trend. This direction is orthogonal to the general trend of Quaternary normal faults in the region and to the maximum horizontal stress related to the present extensional regime. According to previous studies in other areas, such a directional effect is interpreted as due to the presence of fault‐related fracture fields, polarization being orthogonal to their predominant direction. A comparison with S wave anisotropy inferred from shear wave splitting indicates an orthogonal relation between horizontal polarization and fast S wave direction. This suggests that wavefield polarization and fast velocity direction are effects of the same cause: The existence of an anisotropic medium represented by fractured rocks where shear wave velocity is larger in the crack‐parallel component and compliance is larger perpendicularly to the crack strike. The latter is responsible for the observed anisotropic pattern of amplitudes of horizontal ground motion in the study area.
Ilmenite mapping of the lunar regolith over Mare Australe and Mare Ingenii regions: An optimized multisource approach based on Hapke radiative transfer theory
Authors: Lemelin Myriam , Morisset Caroline‐Emmanuelle , Germain Mickaël , Hipkin Victoria , Goïta Kalifa , Lucey Paul G.
Published: December 2013

We model lunar ilmenite abundances over Mare Australe and Mare Ingenii regions using a new approach; we integrate Lunar Reconnaissance Orbiter Wide Angle Camera (WAC) and Clementine UV‐visible/near‐infrared (UVVIS/NIR) data to obtain a 14‐band mosaic (320‐2000 nm). We use Hapke's radiative transfer equations to compute spectra for various mixtures of orthopyroxene, clinopyroxene, plagioclase, olivine, and ilmenite, with varying grain size, chemistry, and degree of maturity, and find the closest match between the modeled spectra and the spectra of the less mature pixels (optical maturity ≥ 0.2) in the 14‐band mosaic. We calculate a “maximum stoichiometrically possible ilmenite content”, using Clementine‐derived TiO2 abundances and the amount of TiO2 in stoichiometric ilmenite, and use it as a constraint in our model. We validate our methodology with lunar soil spectra of known composition. Our results show that the integrated WAC‐UVVIS/NIR data and the UVVIS/NIR data overestimate ilmenite abundances by 8.80 wt % and 7.97 wt %, respectively, when a fixed maximum of 20 wt % ilmenite is used. When the maximum stoichiometrically possible ilmenite content is used as a constraint, the integrated WAC‐UVVIS/NIR data give slightly more accurate ilmenite abundance estimation (±2.87 wt %) than when using only UVVIS/NIR data (± 3.04 wt %). We find ilmenite concentrations of 0−11 wt % in Mare Australe and 0−6 wt % in Mare Ingenii region. Ilmenite abundances between 4 and 7 wt % are exposed in Mare Australe, whereas ilmenite abundances between 7 and 11 wt % are found on the walls of 0.6‐11.8 km diameter craters within Mare Australe.
Simulation of the 23 July 2012 extreme space weather event: What if this extremely rare CME was Earth directed?
Authors: Ngwira Chigomezyo M. , Pulkkinen Antti , Leila Mays M. , Kuznetsova Maria M. , Galvin A. B. , Simunac Kristin , Baker Daniel N. , Li Xinlin , Zheng Yihua , Glocer Alex
Published: December 2013

Extreme space weather events are known to cause adverse impacts on critical modern day technological infrastructure such as high‐voltage electric power transmission grids. On 23 July 2012, NASA's Solar Terrestrial Relations Observatory‐Ahead (STEREO‐A) spacecraft observed in situ an extremely fast coronal mass ejection (CME) that traveled 0.96 astronomical units (∼1 AU) in about 19 h. Here we use the Space Weather Modeling Framework (SWMF) to perform a simulation of this rare CME. We consider STEREO‐A in situ observations to represent the upstream L1 solar wind boundary conditions. The goal of this study is to examine what would have happened if this Rare‐type CME was Earth‐bound. Global SWMF‐generated ground geomagnetic field perturbations are used to compute the simulated induced geoelectric field at specific ground‐based active INTERMAGNET magnetometer sites. Simulation results show that while modeled global SYM‐H index, a high‐resolution equivalent of the Dst index, was comparable to previously observed severe geomagnetic storms such as the Halloween 2003 storm, the 23 July CME would have produced some of the largest geomagnetically induced electric fields, making it very geoeffective. These results have important practical applications for risk management of electrical power grids.
Learning, Education, and Public Programs in Museums and Galleries
Authors: Reeve John , Woollard Vicky
Published: December 2013

The role and place of learning in museums has been transformed in the past 20 years through a shared global community of practice. These transformations are both generic in terms of museological practice and specific to local cultures and conditions. For many, learning has moved from the margins to the core and is now central to what a museum or gallery is and does. We review the last two decades of work in learning and education to find what have been the factors for change and how these have shaped current museum practice. Our approach is bibliographical, citing the extensive literature on museums and learning from many perspectives that is itself an indication of a revolution in the theory, discourse, and delivery. We are entering a difficult period economically and politically, where there can be no presumptions as to the availability of financial support and the place cultural activities will have in the public's conscience. In order to strip back to the basics of museum and gallery learning to see what may remain, we question what will be the sustainable parts of public programs and what will disappear, and to what extent audience participation and collaboration will reduce the need for professional museum and gallery educators.
Emotions in the History Museum
Authors: Watson Sheila
Published: December 2013

Research into communication strategies in museums and galleries has focused mainly on visitors’ learning and their cognitive responses. However, our thoughts and ideas are mediated through our emotions, which are historically and culturally situated. Using case studies, this chapter seeks to open a discussion about the place of emotions in museums. Focusing in particular on the discipline of history and history museums, it suggests that we need to pay more attention to affect and the emotions generated by the museum visit.
Lighting Practices in Art Galleries and Exhibition Spaces, 1750–1850
Authors: Barnaby Alice
Published: December 2013

At the end of the eighteenth century, diverse theories about appropriate architectural styles for displaying and viewing art were formulated, but by the middle of the following century a general consensus had been established and an increasingly standardized approach to lighting was adopted. The preference was for the architectural mode of top lighting. In art galleries and museums, top lighting seemed the appropriate, progressive mode for newly public institutions. It expressed patrician beliefs in the power of comprehensive vision, the refinement of mental faculties, and the common pursuit of knowledge for the greater good of society. Originating in values of civic humanism and an Enlightenment emphasis on the importance of rational thought and intellectual endeavor, a patrician mode of light came to dominate public aesthetic experiences. However, as this chapter shows, the path to standardized aesthetic appreciation was not entirely smooth, nor was it comprehensively adopted. For a period of approximately 60 years an alternative mode of architectural lighting, characterized by variable and heightened effects of color and contrast, coexisted temporarily with patrician lighting. This alternative, and sometimes artificial, lighting style is best described as “poetic” and is exemplified in much of the work of Sir John Soane. Poetic lighting sought to create an embodied and perceptually dynamic aesthetic encounter, as opposed to patrician light which endeavored to create a collective and normalized atmosphere for acts of perceptual experience.
Copper(I) Fluorescent Probes
Authors: Morgan M. Thomas , Bagchi Pritha , Fahrni Christoph J.
Published: December 2013

Metal‐ion‐responsive fluorescent probes are routinely used for the detection of metal ions in biological samples, for the determination of metal‐binding affinities of proteins and for the noninvasive visualization of exchangeable metal ion pools in live cells, tissues, and whole organisms. While a large array of fluorescent probes have been developed for nonredox‐active biological metal ions, the literature on copper‐selective probes for biological applications is comparatively sparse. Within the reducing cellular environment, copper is mostly present in its monovalent oxidation state. The development of biological copper probes is therefore facing the challenges posed by the rich redox and coordination chemistry of Cu(I). This article outlines these challenges in a systematic manner by starting with a brief review of the relevant thermodynamic aspects of Cu(I) solution equilibria, followed by discussing the design of fluorescent Cu(I) probes and the optimization of their photophysical properties.
Zinc: Fluorescent Sensors
Authors: Palmer Amy E. , Miranda Jose G. , Carter Kyle P.
Published: December 2013

Fluorescent sensors for visualizing Zn(II) in living cells permit researchers to quantify the amount of Zn(II), define where Zn(II) is located at the subcellular level, and track dynamics of Zn(II) in response to cellular stimuli. Sensors have been developed in all three major classes: small‐molecule indicators, genetically encoded sensors composed of fluorescent proteins, and hybrid probes that contain a genetically encoded element combined with an exogenous cofactor. Probes have been targeted to mitochondria,
endoplasmic reticulum
(
ER
), Golgi, nucleus, plasma membrane, vesicles, and cytosol in order to monitor Zn(II) in these locales. This article summarizes the overall design, biophysical, and photophysical properties of the major Zn(II) sensors.
Metal Homeostasis: Sparing and Salvaging Metals in Chloroplasts
Authors: Blaby‐Haas Crysten E. , Merchant Sabeeha S.
Published: December 2013

Chloroplast function is dependent on the acquisition and correct allocation of metal cofactors. When the plant encounters a shortage of metal, programmed responses involving sparing and salvaging of the limiting nutrient are activated to ensure that necessary proteins are metalated at the expense of proteins with dispensable functions. These mechanisms operate at the transcriptional, translational, and post‐translation levels, and serve to widen the window of metal concentrations, in which the plant can survive. Mainly by taking advantage of microbial reference organisms, several classic examples of chloroplast metal sparing and salvaging are available. These include the plastocyanin/cytochromec6switch in cyanobacteria and algae, themicroRNAs(miRNAs)‐mediated copper economy in land plants, and the programmed degradation of the photosynthetic machinery during iron deficiency in algae.
Iron and Heme Transport and Trafficking
Authors: Yien Yvette Y. , Paw Barry H.
Published: December 2013

Genetic defects in iron acquisition and export, and heme metabolism can result in pathologies including congenital anemia or porphyria. While the enzymes that govern heme synthesis have been elucidated and characterized, the proteins and genes that govern the transport of iron, heme, and heme intermediates are poorly studied. Knowledge of these transport mechanisms will shed light on important regulatory steps that govern heme and iron metabolism. This article focuses on summarizing current studies on heme, heme intermediates and iron transport, and attempts to identify gaps in our knowledge of these transport pathways. Additionally, we will highlight the contribution of model organisms to the understanding of heme/iron metabolism.
Metal Specificity of Metallosensors
Authors: Higgins Khadine A. , Giedroc David P.
Published: December 2013

Transition metal ions are biologically required yet toxic when in excess. As such, prokaryotes have developed metal homeostasis systems that allow for the acquisition of essential metal ions, the delivery of these metal ions to target proteins, and the export of metal ions from the cell. Specialized metal‐binding proteins termedmetallosensorsbind to a cognate metal ion(s) in the cell and either transcriptionally repress the expression of importers or de‐repress the expression of exporters or sequestration systems and therefore govern cellular metal homeostasis. Metallosensors must be selective and appropriately sensitive toward the binding of their cognate metals. Prokaryotic metallosensors have been identified in ten different protein structural families. Each family exploits either one general metal‐binding‐site region, individual members of which have evolved different coordination sites, or alternatively, employs multiple metal‐binding sites to effect coordination of different metal ions. There is now broad support for the hypothesis that metal responsiveness in metallosensors is most closely linked to the coordination number and geometry adopted by cognate metal ion(s), and this is the subject of this article. Since a range of metal ions can be collectively sensed by a single repressor family, a particular protein fold cannot be specific for one particular metal ion. In fact, the converse is true: nature has used convergent evolution to evolve metal‐specific sensors on a variety of structural scaffolds that exploit common principles of coordination chemistry (ligand type, coordination number, and geometry) to effect the same biological outcome.
Copper Homeostasis: Regulation in Plants
Authors: Pilon Marinus , Tapken Wiebke
Published: December 2013

Copper (Cu) is essential for plant life because of its key role in photosynthetic electron transport, respiration, and perception of the plant hormone ethylene. The most abundant Cu protein in plants is plastocyanin, an electron carrier in the chloroplast thylakoid lumen that is essential for photoautotrophic growth of plants. Copper is also a cofactor of superoxide dismutase and a number of extracellular cell wall enzymes for which the biological function is not yet fully elucidated. Cellular uptake is accomplished by theCopTCu(I) family of transporters.CopT1andCopT2are especially important at the root surface, whereasCopT6is important for Cu uptake in green cells.CopT5serves to release Cu from vacuolar stores. Members of the largeZIPfamily of divalent metal transporters might add capacity for uptake of Cu(II). Members of the yellow stripe‐like (YSL) family are proposed to function in the transport of Cu(II) complexed to the chelator nicotianamine, which might be important for mobilization of Cu from vegetative tissues to developing seeds.ATP‐dependent P‐typeATPasesof theHMAfamily transport Cu(I) out of the cytosol. Of these P‐typeATPases,HMA5serves to allow Cu exit from the cell, which is required for tolerance to excess and for long‐distance root‐to‐shoot transport in the vasculature. OtherHMAtransporters deliver the Cu cofactor to the ethylene receptors in the endomembrane system (HMA7) or to the chloroplasts (HMA6). A fourth Cu‐transporting P‐TypeATPase(HMA8) delivers Cu to plastocyanin in the thylakoid lumen. Cu‐specific metallochaperones have been identified in plants similarly to other eukaryotes. Under impending Cu deficiency, plants use three mechanisms to adjust their physiology. The cell‐surface‐localizedCopTtransporters are up‐regulated in response to low Cu availability in the cytosol via the conserved Cu‐responsive transcription factorSPL7in order to up‐regulate assimilation. In addition, plants enter a Cu economy mode by theSPL7‐mediated up‐regulation of a set of smallRNAmolecules called thecoppermicroRNAsbecause they target the messengerRNAsthat encode for certain apparently dispensable Cu proteins. This mechanism should ensure that enough Cu is left for essential functions such as photosynthesis. Finally, theHMA8transporter in the thylakoid membrane undergoes turnover, but low Cu availability stabilizes the transporter to ensure efficient delivery of Cu to plastocyanin. Together, these homeostatic mechanisms fine‐tune cellular and whole plant Cu distribution and allow plants to thrive on a broad range of Cu concentrations.