bluuebunny/crossref_metadata_2025 huggingface dataset:
« Divines entreprises » sur la toile
Authors: Laugrand Frédéric , Braën Caroline
Published: April 2014

L’étude privilégie l’information contenue dans les réseaux électroniques pour décrire et analyser les mouvements pentecôtiste et évangélique présents en sol canadien et sur le Web. A travers l’examen de cette vaste entreprise de réseautage, il cherche à voir comment ces groupes se mettent en valeur, recrutent de nouveaux leaders et financent leurs opérations. Quels sont donc les principaux groupes évangélique et pentecôtiste actifs auprès des Premières Nations et des Inuit qui occupent le Web ? Comment opèrent-ils pour atteindre leurs objectifs ? Quelles sont leurs activités et leurs stratégies ? Quelle est l’ampleur des ramifications qu’ils établissent et s’y produit-il une indigénisation ? Quelles sont enfin les stratégies de communication employées par les différents groupes pour convaincre leurs visiteurs ? Une première partie dresse un bref portrait des groupes évangéliques et pentecôtistes les plus anciens qui sont aujourd’hui actifs sur le Web. La seconde partie présente une analyse diachronique puis synchronique de groupes plus récents dont il fait ressortir certaines caractéristiques communes. Les recherches qui alimentent ce travail ont été effectuées de 2009 à 2012. Elles ont permis d’identifier un peu plus d’une quarantaine de sites Web évangéliques et pentecôtistes s’adressant aux Premières Nations et aux Inuit du Canada. Ce corpus n’est cependant pas exhaustif, car un grand nombre d’églises locales disposent de leur propre site. Les auteurs ont également examiné des médias et des journaux, comme Faith Today et The Mantle (www.iaogcan.com/mantle.html) pour mieux saisir leur rôle dans les différents réseaux.
DYNAMIC BUILDING SIMULATIONS FOR THE ESTABLISHMENT OF A MOROCCAN THERMAL REGULATION FOR BUILDINGS
Authors: Sick Friedrich , Schade Stefan , Mourtada Adel , Uh Dieter , Grausam Michael
Published: April 2014

Comprehensive dynamic building simulations are used in order to conduct sensitivity analyses on the influence of building shell parameters to the heating and cooling demands of a variety of building types in Morocco. In a first step, five climatic zones are defined covering the range of specific heating and cooling demand combinations of a reference building located in eleven locations throughout Morocco. Afterwards, 22 single parameter variations for each building type and each climate zone are performed and analyzed in such a way, that suitable promising combinations can be defined as well. This procedure is faster and easier to analyze than a multidimensional regression. The results show indeed that the selected combinations may reduce energy demands substantially. This paper explains the procedure and results in detail for one residential type of building and for one typical non-residential building. The major overall results are discussed.
MASS FLOW RATE INDUCED BY COMBINED ROOF SOLAR COLLECTOR AND VERTICAL STACK IN A HOT HUMID CLIMATE
Authors: Yusoff Wardah Fatimah Mohammad , Sapian Abdul Razak , Salleh Elias , Adam Nor Mariah , Hamzah Zabidi
Published: April 2014

This paper presents the investigation of solar induced ventilation that utilizes roof solar collector and vertical stack. Three prototypes, namely A, B and C, were developed based on preliminary experimental work. They were then used in simulation study with the objective of determining the prototype that was able to induce the highest mass flow rate. The validation of simulation modelling against experiment indicated a good agreement between these two results. The findings showed that prototype A induced the highest mass flow rate. However, prototype C, which had obstructions at the stack outlets, was more appropriate for application in Malaysia due to various prevailing wind directions. In addition, the findings also indicated that besides solar radiation, the mass flow rate induced by the prototypes was also influenced by the local wind direction, the inlet and outlet positions as well as the outlet design. In summary, the findings highlighted the potential application of the proposed solar induced ventilation in a hot and humid climate.
Generation Scheduling Based on Two-Level Optimization Problem
Authors: Nechaev I. A. , Palamarchuk S.I.
Published: April 2014

A two-level problem for electricity generation scheduling in the wholesale market environment is proposed. The lower level of the problem corresponds to System Operator's (SO) efforts to schedule generation and calculate local marginal prices (LMPs) on the basis of total production cost minimization. The upper level corresponds to the profit maximization of each Generating Company (GC) with true cost functions and true generation ranges. The lower level of the problem is represented as a Mathematical Program with Equilibrium Constraints (MPEC). The problem is deemed solved, when the Nash equilibrium point is reached among strategic producers. The two-level optimization problem is formulated and the method for its solving is developed. A numerical example of a 15-bus Electric Power System (EPS) with thermal and hydro power plants is used to test the applicability of the approaches. The efficiency of the proposed approach is shown in comparison with traditional methods.
Thermal Properties Study of a Solar Water Heater Tank with a Mantle Exchanger
Authors: Chikhi Mourad , Sellami Rabah , Merzouk Nachida Kasbadji
Published: April 2014

The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For development solar water heaters, the incentive programs are supported by the Algerian government to generalize the using of this kind of energy especially in Sahara. This study is a part of program to develop a new solar water heater in UDES (Algeria). In this research work, the thermal performance of a solar water heater with a mantle heat exchanger is investigated numerically using Comsol Multyphysics software. The objective is to investigate the influence of the mantle heat exchanger thickness on the performance of solar water heaters. The results show, for 160 liters capacity of the solar water heaters tank, the 13mm of the heat exchanger thickness leads to improve the efficiency of the solar water heater.
CHIS
Authors: Colace F. , De Santo M. , Greco L. , Chianese A. , Moscato V. , Picariello A.
Published: April 2014

The Campania region boasts one of the largest and most priceless cultural heritages in the world: five sites in this region have already been declared a World Heritage Site by UNESCO and many other sites considered “minor” are not adequately promoted in spite of the fact they are of high artistic value. The project “Cultural Heritage Information System,” (referred to from now on as “CHIS”), aims to investigate the possibility of developing a technological infrastructure that can support activities related to the specific context of Cultural Heritage, and the various user involved. CHIS represents the technological leverage with which it will be possible to develop value-added services which can enhance the business environment by means of personalized services. In this paper the authors will describe the proposed framework and its main characteristics.
Exploring the Affordances of Facebook Groups
Authors: Stefanou Vassilia
Published: April 2014

This case study explores the affordances of a specific Facebook group created by college students, as perceived by the group members. The main focus is to investigate if Facebook groups have an educational value. Furthermore, three secondary research topics emerged: comparison of the group's perceived affordances of faculty as opposed to the ones of students; comparison of the group's perceived affordances with the ones of Blackboard LMS; and comparison of the group's perceived affordances with the ones of a standard mailing list.
Value Creation in Business-to-Business Crowdsourcing
Authors: Helander Nina , Jussila Jari , Kärkkäinen Hannu
Published: April 2014

In knowledge society the utilization of social media as a communication channel between people, groups and even companies is increasing. Current innovation and social media research has already shown the potential of crowdsourcing in the business-to-consumer (B2C) markets. The authors argue in this paper, however, that crowdsourcing has a great and yet partly undiscovered potential also in the context of business-to-business (B2B) markets. In order to get the full potential, a more detailed understanding of the logic of value creation in crowdsourcing activities between multiple stakeholders in B2B context is needed. This paper presents an exploratory study that is carried out as an empirical netnography-based multiple case study. The study opens up potential future research avenues by starting the discussion of value creation logic in B2B crowdsourcing. Practical implications are created through cases revealing what kind of value companies have already been able to gain from crowdsourcing in B2B context.
Impact of Board Heterogeneity Composition on Firm Risk
Authors: Kim Kong-Hee , Rasheed Abdul A.
Published: April 2014

There has been scant research exploring the implications of board heterogeneity for board's functioning and subsequent corporate outcome of stability in firm performance. A number of hypotheses are developed based on a multi-theoretic approach incorporating board resources, board dynamics, and board independence. Results of testing the hypotheses reveal that board heterogeneity in organizational tenure, functional experience, and educational specialty is related to the stability of returns. Furthermore, increased ownership position by directors and institutional investors strengthens the relationship between board heterogeneity and stability of returns. The results of this study suggest that board heterogeneity increases organizational rationality and further the stability in firm performance through its more effective control and counsel functions to management.
A Threat-Response Model of Counter-Terrorism
Authors: Wood William C. , O'Roark J. Brian , DeLaCruz Lauren M.
Published: April 2014

This paper critically reviews the literature and best practices to develop and apply a qualitative model for managing terrorism threats. The research shows how risk is too complicated to be reduced to a binary system of safe and unsafe attributes. The researchers show how uncertainty can be reduced through the application of resources, by using a protection profile. The second component in the model is a damage profile, which shows how, as security increases, the additional value of more security decreases. When this relationship is adjusted for the costs of security (reflected in the protection profile), the result is an equilibrium showing an economically-rationalized level of security but generally short of complete safety. The model is then simulated to show how the equilibrium is shifted by such factors as an increase in vulnerability or consequences, a more effective adversary, changed costs and advances in technology. Although an equilibrium model with known functions is useful, a number of real-world limitations prevent straightforward application of the model to calculate a security equilibrium. These limitations include discontinuous risks and distributed decision-making authority. Finally, the model is analyzed to estimate the likely effects of litigation and security mandates on counter-terrorism.
Aspects Regarding Implementation of Renewable Energy Sources in Romania up to 2050
Authors: Dusmanescu Dorel
Published: April 2014

The paper describes the tendencies in the implementation of renewable energy sources in Romania until 2050. It is presented some arguments to justify the necessity to implement the renewable energy sources. Using the potential of renewable sources previously estimated for Romania are presented two scenarios with the necessary considerations.
The Implementation of Rural Heritage Measures in Ukraine
Authors: Moroz Serhiy
Published: April 2014

The paper describes the current state and tendencies in the development of rural heritage in Ukraine. Special attention is given to the nature reserve fund, forests, water resources, and historical-cultural objects. The preparatory steps for the implementation of rural heritage measures are presented, taking into account the necessity of the adaptation of the rural development policy of Ukraine to the requirements of the European Union. The aims, objects, and main directions of measures regarding the preservation of cultural and natural heritage in the rural regions of Ukraine are identified. The indicators for the evaluation of rural heritage measures are proposed.
The Kosovo Agriculture Market and the Marketing Concept
Authors: Pllana Mustafa , Miftari Iliriana , Bytyqi Njazi , Aliu Sali , Shkodra Jehona
Published: April 2014

Considering marketing as main contributor to the contemporary development, it has encouraged us to raise discussion regarding the role of the marketing in business decision-making and economic development as a whole. The concept of marketing is becoming a necessity tool for survival and the development of different business enterprises. The main objective of the study was to find out about the level at which Kosovo enterprises understand and apply marketing and how do they distinguish marketing from advertising. Moreover, the study seeks for Kosovo households' opinion on marketing and advertising, if they distinguish it from advertising, and how the advertising influences the household behavior in buying decision making. A sample size of 150 businesses and 150 household, covering the whole Kosovo regions were interviewed and analyzed. The results of the collected data were processed and analyzed using Statistical Program for Social Sciences (SPSS).Out of 46% of the total surveyed businesses considered that adv is same as marketing .About 64% of surveyed households declared that adv is done for the products of low quality, but 62% of businesses consider adv necessity even for products of best quality. Surveyed households, about 63% declared that their bought has been based on previous purchases, 17% on sellers' statement and 20% on adv basis. The share for promotion by some Kosovo agriculture businesses is from 4% to 20% of the profit, increasing the selling from 3% to 10%.
Restrictive Factors for Economic Growth in Developing Countries
Authors: Ion Bucur , Cristian Bucur
Published: April 2014

Economic growth reflects the ability of an economy to produce more goods, in the structure and quality demanded by consumers. Growth influence decisive the existing living standard in a country. Developing countries are characterized in a greater extent than developed countries by insufficient financial resources designed both to increase the volume of investment resources and their efficient use. Increasing economic resources requires investments and lead to increased production.
Identifying Different Forms of Innovation in Retail Banking
Authors: Favre-Bonte Véronique , Elodie Gardet , Thevenard-Puthod Catherine
Published: April 2014

To be competitive and capture new customers, banks must develop continuous innovations that can reduce costs, enhance existing service quality, expand current service offerings, and increase market share. This article proposes a typology of different types of innovation in the retail banking sector on the basis of a case study of the leading French credit institution, Crédit Agricole. This bank does not innovate just incrementally, and radical innovations resulted from the launch of a new distribution channel, though several innovations are unrelated to new technology. This study adds to literature on innovation services by enhancing understanding of the different types of innovation. The empirical investigation further shows that the banking sector can develop process innovations, which give the bank a longer term competitive advantage. To innovate radically, the bank should anticipate the impact of its new offerings on different areas of the system.
Calpain-1 Contributes to IgE-Mediated Mast Cell Activation
Authors: Wu Zhengli , Chen Xiaochun , Liu Fang , Chen Wei , Wu Ping , Wieschhaus Adam J. , Chishti Athar H. , Roche Paul A. , Chen Wei-Min , Lin Tong-Jun
Published: April 2014

Mast cells play a central role in allergy through secretion of both preformed and newly synthesized mediators. Mast cell mediator secretion is controlled by a complex network of signaling events. Despite intensive studies, signaling pathways in the regulation of mast cell mediator secretion remain incompletely defined. In this study, we examined the role of calpain in IgE-dependent mast cell activation. IgE-mediated activation of mouse bone marrow–derived mast cells enhanced calpain activity. Inhibition of calpain activity by a number of calpain inhibitors reduced IgE-mediated mast cell degranulation both in vitro and in vivo. Calpain inhibitors blocked IgE-mediated TNF and IL-6 production in vitro and reduced late-phase allergic response in vivo. Importantly, mouse calpain-1 null bone marrow–derived mast cells showed reduced IgE-mediated mast cell degranulation in vitro and in vivo, diminished cytokine and chemokine production in vitro, and impaired late-phase allergic response in vivo. Further studies revealed that calpain-1 deficiency led to specific attenuation of IκB–NF-κB pathway and IKK–SNAP23 pathway, whereas calcium flux, MAPK, Akt, and NFAT pathway proceed normally in IgE-activated calpain-1 null mast cells. Thus, calpain-1 is identified as a novel regulator in IgE-mediated mast cell activation and could serve as a potential therapeutic target for the management of allergic inflammation.
The β Subunit of the Type I Fcε Receptor Is a Target for Peptides Inhibiting IgE-Mediated Secretory Response of Mast Cells
Authors: Andrásfalvy Márton , Péterfy Hajna , Tóth Gábor , Matkó János , Abramson Jakub , Kerekes Krisztina , Vámosi György , Pecht Israel , Erdei Anna
Published: April 2014

Peptides originally derived from complement component C3a were earlier shown to inhibit the type I FcεR (FcεRI)-mediated degranulation of mucosal type mast cells. In the present study, we show that C3a7, a peptide with a natural sequence, and its modified derivative, C3a9, are powerful inhibitors of the above response of both serosal and mucosal type mastocytes. We demonstrate that these peptides inhibit FcεRI-induced membrane proximal events, suppress phosphorylation of the FcεRI β subunit, the protein tyrosine kinase Lyn, as well as the transient rise in free cytosolic Ca2+ level. The late phase of cellular response was also inhibited, as demonstrated by the reduced TNF-α secretion. Experiments using two independent methods provided evidence that the interaction site of complement-derived peptides is the FcεRI β-chain. This was further supported by fluorescence confocal microscopic colocalization and resonance energy transfer measurements. Taken together, these results suggest the presence of distinct “activating” and “inhibitory” motifs in the C3a sequence. Response to both is in balance under physiologic conditions. Furthermore, present data predict that such inhibitory peptides may serve as potent agents for future therapeutic intervention.
Costimulation through NKG2D Enhances Murine CD8+ CTL Function: Similarities and Differences between NKG2D and CD28 Costimulation
Authors: Markiewicz Mary A. , Carayannopoulos Leonidas N. , Naidenko Olga V. , Matsui Ken , Burack W. Richard , Wise Erica L. , Fremont Daved H. , Allen Paul M. , Yokoyama Wayne M. , Colonna Marco , Shaw Andrey S.
Published: April 2014

Multiple studies have demonstrated that the NK cell activating receptor NKG2D can function as a costimulatory receptor for both mouse and human CD8+ T cells. However, it has recently been suggested that stimulation through NKG2D is insufficient for costimulation of CD8+ T cells. To aid in the delineation of NKG2D function in CTL responses, we investigated whether stimulation of NKG2D by the natural ligand RAE1ε was able to costimulate effector functions of a murine CTL line generated from DUC18 TCR transgenic mice. We found that NKG2D was able to costimulate DUC CTL responses and did so in a manner similar to CD28 costimulation. The T cells exhibited increased proliferation, IFN-γ release, and cytotoxicity when presented antigenic peptide by P815 cells expressing RAE1ε or B7-1 compared with untransfected P815. In addition, both RAE1ε and B7-1 enhanced Ag-independent IFN-γ secretion in response to IL-12 and IL-18 by DUC CTL. However, only costimulation through CD28 allowed for DUC CTL survival upon secondary stimulation, whereas ligation of NKG2D, but not CD28, induced DUC CTL to form an immune synapse with target cells in the absence of TCR stimulation. Understanding the outcomes of these differences may allow for a better understanding of T cell costimulation in general.
Intracellular Bacteria Differentially Regulated Endothelial Cytokine Release by MAPK-Dependent Histone Modification
Authors: Schmeck Bernd , Beermann Wiebke , van Laak Vincent , Zahlten Janine , Opitz Bastian , Witzenrath Martin , Hocke Andreas C. , Chakraborty Trinad , Kracht Michael , Rosseau Simone , Suttorp Norbert , Hippenstiel Stefan
Published: April 2014

Epigenetic histone modifications contribute to the regulation of eukaryotic gene transcription. The role of epigenetic regulation in immunity to intracellular pathogens is poorly understood. We tested the hypothesis that epigenetic histone modifications influence cytokine expression by intracellular bacteria. Intracellular Listeria monocytogenes, but not noninvasive Listeria innocua, induced release of distinct CC and CXC chemokines, as well as Th1 and Th2 cytokines and growth factors by endothelial cells. Cytokine expression was in part dependent on p38 MAPK and MEK1. We analyzed global histone modification and modifications in detail at the gene promoter of IL-8, which depended on both kinase pathways, and of IFN-γ, which was not blocked by kinase inhibition. Intracellular Listeria induced time-dependent acetylation (lysine 8) of histone H4 and phosphorylation/acetylation (serine 10/lysine 14) of histone H3 globally and at the il8 promoter in HUVEC, as well as recruitment of the histone acetylase CREB-binding protein. Inhibitors of p38 MAPK and MEK1 reduced lysine 8 acetylation of histone H4 and serine 10/lysine 14 phosphorylation/acetylation of histone H3 in Listeria-infected endothelial cells and disappearance of histone deacetylase 1 at the il8 promoter in HUVEC. In contrast, IFN-γ gene transcription was activated by Listeria monocytogenes independent of p38 MAPK and MEK1, and histone phosphorylation/acetylation remained unchanged in infected cells at the IFN-γ promoter. Specific inhibition of histone deacetylases by trichostatin A increased Listeria-induced expression of IL-8, but not of IFN-γ, underlining the specific physiological impact of histone acetylation. In conclusion, MAPK-dependent epigenetic modifications differentially contributed to L. monocytogenes-induced cytokine expression by human endothelial cells.
Enhanced Macrophage Activity in Granulomatous Lesions of Immune Mice Challenged with Mycobacterium tuberculosis
Authors: Ordway Diane , Harton Marisa , Henao-Tamayo Marcela , Montoya Rose , Orme Ian M. , Gonzalez-Juarrero Mercedes
Published: April 2014

In this study, we evaluated the cellular influx and cytokine environment in the lungs of mice made immune by prior vaccination with Mycobacterium bovis bacillus Calmette-Guérin compared with control mice after infection with Mycobacterium tuberculosis to characterize composition of protective lesions in the lungs. Immune mice controlled the growth of the M. tuberculosis challenge more efficiently than control mice. In immune animals, granulomatous lesions were smaller and had a more lymphocytic core, less foamy cells, less parenchymal inflammation, and slower progression of lung pathology than in lungs of control mice. During the chronic stage of the infection, the bacterial load in the lungs of immune mice remained at a level 10 times lower than control mice, and this was associated with reduced numbers of CD4P+P and CD8P+P T cells, and the lower expression of protective (IL-12, IFN-γ), inflammatory (TNF-α), immunoregulatory (GM-CSF), and immunosuppressive (IL-10) cytokines. The immune mice had higher numbers of CD11b−CD11chighDEC-205low alveolar macrophages, but lower numbers of CD11b+CD11chighDEC-205high dendritic cells, with the latter expressing significantly lower levels of the antiapoptotic marker TNFR-associated factor-1. Moreover, during the early stage of chronic infection, lung dendritic cells from immune mice expressed higher levels of MHC class II and CD40 molecules than similar cells from control mice. These results indicate that while a chronic disease state is the eventual outcome in both control and immune mice infected with M. tuberculosis by aerosol exposure, immune mice develop a protective granulomatous lesion by increasing macrophage numbers and reduced expression of protective and inflammatory cytokines.
IFN-γ Primes RAW264 Macrophages and Human Monocytes for Enhanced Oxidant Production in Response to CpG DNA via Metabolic Signaling: Roles of TLR9 and Myeloperoxidase Trafficking
Authors: Adachi Yoshiyuki , Kindzelskii Andrei L. , Petty Aaron R. , Huang Ji-Biao , Maeda Nobuyo , Yotsumoto Satoshi , Aratani Yasuaki , Ohno Naohito , Petty Howard R.
Published: April 2014

Macrophages and monocytes are activated by CpG DNA motifs to produce NO, which is enhanced dramatically by IFN-γ. We hypothesize that synergistic cellular responses to IFN-γ and CpG DNA are due to cross-talk between metabolic signaling pathways of leukocytes. Adherent RAW264.7 macrophages and human monocytes exhibited NAD(P)H autofluorescence oscillation periods of ∼20 s. IFN-γ increased the oscillatory amplitude, which was required for CpG DNA-mediated metabolic changes. These alterations in metabolic dynamics required the appropriate combinations of murine/human TLR9 and murine/human-specific CpG DNA. Other factors that also promoted an increase in metabolic oscillatory amplitude could substitute for IFN-γ. Because recent studies have shown that the metabolic frequency is coupled to the hexose monophosphate shunt, and the amplitude is coupled to the peroxidase cycle, we tested the hypothesis that myeloperoxidase (MPO) participates in IFN-γ priming for oxidant production. MPO inhibitors blocked cell responses to IFN-γ and CpG DNA. In the absence of IFN-γ exposure, the effects of CpG DNA could be duplicated by MPO addition to cell samples. Moreover, monocytes from MPO knockout mice were metabolically unresponsive to IFN-γ and CpG DNA. NAD(P)H frequency doubling responses due to CpG DNA were blocked by an inhibitor of the hexose monophosphate shunt. Because NAD(P)H participates in electron trafficking to NO and superoxide anions, we tested oxidant production. Although CpG DNA alone had no effect, IFN-γ plus CpG enhanced NO and reactive oxygen metabolite release compared with IFN-γ treatment alone. We suggest that amplitude and frequency modulation of cellular metabolic oscillations contribute to intracellular signaling synergy.
On a Sumset Conjecture of Erdős
Authors: Di Nasso Mauro , Goldbring Isaac , Jin Renling , Leth Steven , Lupini Martino , Mahlburg Karl
Published: April 2014

Erdős conjectured that for any set A ⊆ ℕ with positive lower asymptotic density, there are infinite sets B;C ⊆ ℕ such that B + C ⊆ A. We verify Erdős’ conjecture in the case where A has Banach density exceeding ½ . As a consequence, we prove that, for A ⊆ ℕ with positive Banach density (amuch weaker assumption than positive lower density), we can find infinite B;C ⊆ ℕ such that B+C is contained in the union of A and a translate of A. Both of the aforementioned results are generalized to arbitrary countable amenable groups. We also provide a positive solution to Erdős’ conjecture for subsets of the natural numbers that are pseudorandom.
Algebraic combinatorial geometry: the polynomial method in arithmetic combinatorics, incidence combinatorics, and number theory
Authors: Tao Terence
Published: April 2014

Arithmetic combinatorics is often concerned with the problem of controlling the possible range of behaviours of arbitrary finite sets in a group or ring with respect to arithmetic operations such as addition or multiplication. Similarly, combinatorial geometry is often concerned with the problem of controlling the possible range of behaviours of arbitrary finite collections of geometric objects such as points, lines, or circles with respect to geometric operations such as incidence or distance. Given the presence of arbitrary finite sets in these problems, the methods used to attack these problems have primarily been combinatorial in nature. In recent years, however, many outstanding problems in these directions have been solved by algebraic means (and more specifically, using tools from algebraic geometry and/or algebraic topology), giving rise to an emerging set of techniques which is now known as the
polynomial method
. Broadly speaking, the strategy is to capture (or at least partition) the arbitrary sets of objects (viewed as points in some configuration space) in the zero set of a polynomial whose degree (or other measure of complexity) is under control; for instance, the degree may be bounded by some function of the number of objects. One then uses tools from algebraic geometry to understand the structure of this zero set, and thence to control the original sets of objects.

While various instances of the polynomial method have been known for decades (e.g. Stepanov’s method, the combinatorial Nullstellensatz, or Baker’s theorem), the general theory of this method is still in the process of maturing; in particular, the limitations of the polynomial method are not well understood, and there is still considerable scope to apply deeper results from algebraic geometry or algebraic topology to strengthen the method further. In this survey we present several of the known applications of these methods, focusing on the simplest cases to illustrate the techniques. We will assume as little prior knowledge of algebraic geometry as possible.
Flows on networks: recent results and perspectives
Authors: Bressan Alberto , Čanić Sunčica , Garavello Mauro , Herty Michael , Piccoli Benedetto
Published: April 2014

The broad research thematic of
flows on networks
was addressed in recent years by many researchers, in the area of applied mathematics, with new models based on partial differential equations. The latter brought a significant innovation in a field previously dominated by more classical techniques from discrete mathematics or methods based on ordinary differential equations. In particular, a number of results, mainly dealing with vehicular traffic, supply chains and data networks, were collected in two monographs:
Traffic flow on networks
, AIMSciences, Springfield, 2006, and
Modeling, simulation, and optimization of supply chains
, SIAM, Philadelphia, 2010. The field continues to flourish and a considerable number of papers devoted to the subject is published every year, also because of the wide and increasing range of applications: from blood flow to air traffic management. The aim of the present survey paper is to provide a view on a large number of themes, results and applications related to this broad research direction. The authors cover different expertise (modeling, analysis, numeric, optimization and other) so to provide an overview as extensive as possible. The focus is mainly on developments which appeared subsequently to the publication of the aforementioned books.
Existence and Stability of Periodic Planar Standing Waves in Phase-Transitional Elasticity with Strain-Gradient Effects II: Examples
Authors: Yao Jinghua
Published: April 2014

In a companion paper, we investigated phase-transitional elasticity models with strain-gradient effect, and established the existence of non-constant planar periodic standing waves in these models by variational methods. The variational methods enable us to deal with existence of periodic waves no matter the unknowns are scalar or not. Here, we list specific phase-transitional models with strain-gradient effects and list conditions that guarantee the existence of non-constant periodic waves. Also, when the unknowns are scalars, we do a phase-plane analysis, and compare the results obtained by phase-plane analysis with those obtained by our general variational methods. Finally, we briefly discuss relations between spectral and nonlinear stabilities by using a change of variables introduced by Kotschote to transform our system to a strictly parabolic system to which general results of Johnson–Zumbrun and Howard-Zumbrun apply.
On a Singular Class of Hamiltonian Systems in Dimension Two
Authors: Benaissa Abbes , Khaldi Brahim
Published: April 2014

Let

\Omega

be a bounded domain in

\mathbb{R}^{2}

. In this paper, we consider the following systems of semilinear elliptic equations

\text{(S)}\left\{ \begin{alignedat}{2} -\Delta u&=\tfrac{g(v)}{|x|^{a}}&\quad &\hbox{ in }\Omega \\ -\Delta v&=\tfrac{f(u)}{|x|^{b}}&& \hbox{ in }\Omega\\ u&=v=0&& \hbox{ on }\partial\Omega , \end{alignedat} \right.

where

a,b\in[0, 2)

and the functions

f

and

g

are nonlinearities having an exponential growth on

\Omega

. This nonlinearity is motivated by suitable Trudinger-Moser inequality with a singular weight. In fact, we prove the existence of a nontrivial solution to (S). For the proof we use a variational argument (a linking theorem).
Effort and Performance: What Distinguishes Interacting and Noninteracting Groups from Individuals?
Authors: Besedeš Tibor , Deck Cary , Quintanar Sarah , Sarangi Sudipta , Shor Mikhail
Published: April 2014

We study how group membership affects behavior both when group members can and cannot interact with each other. Our goal is to isolate the contrasting forces that spring from group membership: a free‐riding incentive leading to reduced effort and a sense of social responsibility that increases effort. In an environment with varying task difficulty and individual decision making as the benchmark, we show that the free‐riding effect is stronger. Group members significantly reduce their effort in situations where they share the outcome but are unable to communicate. When group members share outcomes and can interact, they outperform groups without communication and individuals. We show that these groups do as well as the best constituent member would have done on his or her own.
How the Nature of Product Differentiation Affects Procurement Competition
Authors: Thomas Charles J.
Published: April 2014

This article uses computational methods that reveal substantive differences among the equilibrium outcomes from three models of procurement competition: a recently developed model requiring numerical solution and two analytically tractable models that might naturally be considered suitable proxies. The models differ in what sellers know about the buyer's preferences for their products, and they yield substantially different prices and payoffs, different implications for institutional choice, surprising intensities of competition, and qualitatively different comparative statics. These findings caution against using the analytically convenient models when the newer model is empirically appropriate. Reinterpreting the models and results also provides new insights regarding price discrimination in oligopoly.
Nitrogen isotopic response of prokaryotic and eukaryotic phytoplankton to nitrate availability in Sargasso Sea surface waters
Authors: Treibergs Lija A. , Fawcett Sarah E. , Lomas Michael W. , Sigman Daniel M.
Published: April 2014

Taxon‐specific nitrogen (N) isotope data from the summertime Sargasso Sea have previously suggested reliance of prokaryotic phytoplankton on regenerated N but a greater importance of nitrate assimilation for eukaryotic phytoplankton. To investigate this further, particles collected in the summer from ∼ 100 m at the Bermuda Atlantic Time‐series Study site were incubated in particle‐free, unamended surface seawater (from 4 m and 30 m) with measured ambient nitrate and ammonium concentrations. Preincubation and postincubation particles were sorted using flow cytometry, and the δ15N of separated prokaryotic and eukaryotic phytoplankton was analyzed. In July 2009 and 2010, nitrate was undetectable throughout the euphotic zone (the upper ∼ 100 m). The δ15N of prokaryotic biomass was initially low and remained low upon incubation, with one exception out of six. Preincubation eukaryotic δ15N was higher than or similar to prokaryotic δ15N and decreased or remained low after incubation. These data confirm the expectation that, in nitrate‐deplete water, all phytoplankton shift toward a low δ15N characteristic of recycled N assimilation. In June 2010, the euphotic zone nitrate concentration was anomalously high (∼ 1 µmol L−1), and the δ15N of all populations varied as a function of depth, with highest δ15N in the surface where nitrate was lowest. After incubation in surface water, the δ15N of all sorted phytoplankton increased, suggesting nitrate assimilation by all groups, including Prochlorococcus, the nitrate assimilatory capabilities of which have been debated. This study supports the use of the δ15N of sorted phytoplankton as an indicator of the dominant N source fueling their growth.
Physiological modifications of seston in response to physicochemical gradients within Lake Superior
Authors: Bellinger Brent J. , Van Mooy Benjamin A. S. , Cotner James B. , Fredricks Helen F. , Benitez-Nelson Claudia R. , Thompson Jo , Cotter Anne , Knuth Michael L. , Godwin Casey M.
Published: April 2014

In September 2011, we investigated the distribution and composition of dissolved and particulate phosphorus (P) pools throughout Lake Superior, a large P‐limited freshwater ecosystem. Average seston particulate P (PP) concentrations in the deep chlorophyll maximum (DCM; 85 ± 28 nmol L−1) were significantly greater than in the epilimnion (63 ± 22 nmol L−1). In contrast, average particulate organic carbon (POC) : PP (mol : mol) ratios showed the opposite pattern (DCM = 303 : 1 vs. epilimnion = 455 : 1). Mean seston nucleic acid—P concentrations were invariant between the epilimnetic (23 ± 18 nmol L−1) and DCM (26 ± 18 nmol L−1) layers, but significantly greater concentrations of intact polar membrane—derived phospholipids were found in the DCM (6 ± 2 nmol L−1) relative to the epilimnion (4 ± 2 nmol L−1). Phospholipids were a minor proportion of PP (7–14%) and total membrane lipids (< 30%). Rather, our results suggest that microbial flora of Lake Superior substituted non‐phosphorus lipids for phospholipids. In the nitrogen (N)—rich waters, N‐based betaine lipids dominated (39–42%) the lipid pool, and concentrations were significantly greater in the P‐poor epilimnetic seston. Sulfolipids were also abundant and significantly greater in the epilimnion (7 ± 2 nmol L−1) than in the DCM (4 ± 2 nmol L−1), despite low sulfate concentrations relative to marine environments. Our results demonstrate for the first time the importance of plankton producing non‐phosphorus lipids for phospholipids as a strategy for reducing cellular P inventories in lacustrine regimes.
Structural Growth in Labor Costs: Evidence from the Employment Cost Index
Authors: Albrecht Gary R. , Krueger Kurt V.
Published: April 2014

Wage growth forecasting is a necessary part of forensic economics. In this paper, we present a time series methodology to test whether wage and compensation growth in the United States varies by industry and occupation. If growth varies, then the common use of “all-worker” net discount or wage growth rates would not be accurate for every forensic economic case. Using the Employment Cost Index, we find that total compensation, wage, and benefit growth in some, but not all, industries and occupations has been significantly different from that of the wage growth of all workers. That finding may concern the forensic economist who needs to construct a variety of net discount or wage growth rates. As an alternative to constructing multiple forecasts, this paper provides estimated industry and occupational specific differentials from the growth in all workers' wages.
Evolving Labor Market Transition Probabilities and Their Impact on Worklife Estimates
Authors: Cushing Matthew J. , Rosenbaum David I.
Published: April 2014

A panel of age-specific transition probabilities is developed for the three-decade period 1980 to 2010. Analysis shows that both male and female transition probabilities have evolved over the 30-year span. The transition probabilities are used to calculate both period and cohort worklives. The results differ starkly for men and women. For men, worklives are most affected for those with little education. For women, obtaining a college degree has the most impact on worklives. The results suggest that using historical period worklives may have mis-estimated worklives for these two groups relative to cohort estimates.
The Journal of Forensic Economics: Revisiting Its Perspective and Agenda for Research
Authors: Ward John O.
Published: April 2014

This issue of the Journal of Forensic Economics (JFE) begins the 25th volume of that publication. As the first Editor of the JFE and the co-author of the first paper published in that journal, “Forensic Economics: A Perspective and an Agenda for Research” I have been asked to offer comments on the role that the JFE has had in the development of the field of Forensic Economics over the past 25 years. This paper examines the evolution of the journal in terms of the focus of papers published by field of investigation and presents the results of a survey of subscribers on their views on the quality of the JFE, its strengths and its shortcomings. Finally, a new agenda for the JFE is offered that will discuss the primary problems the journal will likely face in the next 25 years and the areas of research to be addressed.
Total Worklife Expectancy
Authors: Krueger Kurt V. , Slesnick Frank
Published: April 2014

This paper appends the standard Markov increment-decrement worklife expectancy model used in forensic economics to measure the years that people perform the non-market work of taking care of their homes or families. We find that adding non-market working years to the worklife model nearly equalizes men and women's estimated lifetime total working years. The paper begins with the gender-related problems of solely using labor force worklife tables as a tort compensation determinant. We then present demographic characteristics of persons that perform full-time, non-market work. A Markov life table model that incorporates two work activities (market and non-market work) is specified—we name the sum of market and non-market working years “total worklife expectancy.” Ending the paper are examples of using total worklife expectancy as a tort compensation estimator.
Using TIPS to Discount to Present Value
Authors: Strangways Raymond , Rubin Bruce L. , Zugelder Michael
Published: April 2014

The practice of forensic economics has a long history of trying to identify the correct interest rate to use when valuing economic losses in personal injury and wrongful death cases. We trace the legal history as it relates to the appropriate interest rates and adjustments for inflation. We then discuss the use of Treasury Inflation Protected Securities, TIPS, and an analysis of the combined effect of realized inflation and taxes on the effective return. We come to the unexpected conclusion that the use of TIPS does not lend itself to a simple adjustment to the rate for taxes nor eliminate the need to consider expected inflation.
Impacts of fire emissions and transport pathways on the interannual variation of CO in the tropical upper troposphere
Authors: Huang L. , Fu R. , Jiang J. H.
Published: April 2014

Abstract. This study investigates the impacts of fire emission, convection, various climate conditions and transport pathways on the interannual variation of carbon monoxide (CO) in the tropical upper troposphere (UT), by evaluating the field correlation between these fields using multi-satellite observations and principle component analysis, and the transport pathway auto-identification method developed in our previous study. The rotated empirical orthogonal function (REOF) and singular value decomposition (SVD) methods are used to identify the dominant modes of CO interannual variation in the tropical UT and to study the coupled relationship between UT CO and its governing factors. Both REOF and SVD results confirm that Indonesia is the most significant land region that affects the interannual variation of CO in the tropical UT, and El Niño–Southern Oscillation (ENSO) is the dominant climate condition that affects the relationships between surface CO emission, convection and UT CO. In addition, our results also show that the impact of El Niño on the anomalous CO pattern in the tropical UT varies strongly, primarily due to different anomalous emission and convection patterns associated with different El Niño events. In contrast, the anomalous CO pattern in the tropical UT during La Niña period appears to be less variable among different events. Transport pathway analysis suggests that the average CO transported by the "local convection" pathway (ΔCOlocal) accounts for the differences of UT CO between different ENSO phases over the tropical continents during biomass burning season. ΔCOlocal is generally higher over Indonesia–Australia and lower over South America during El Niño years than during La Niña years. The other pathway ("advection within the lower troposphere followed by convective vertical transport") occurs more frequently over the west-central Pacific during El Niño years than during La Niña years, which may account for the UT CO differences over this region between different ENSO phases.
Aircraft measurements of polar organic tracer compounds in tropospheric particles (PM10) over central China
Authors: Fu P. Q. , Kawamura K. , Cheng Y. F. , Hatakeyama S. , Takami A. , Li H. , Wang W.
Published: April 2014

Abstract. Atmospheric aerosol samples were collected by aircraft at low to middle altitudes (0.8–3.5 km a.g.l.) over central East to West China during summer 2003 and spring 2004. The samples were analyzed for polar organic compounds using a technique of solvent extraction/BSTFA derivatization/gas chromatography–mass spectrometry. Biogenic secondary organic aerosol (SOA) tracers from the oxidation of isoprene were found to be more abundant in summer (3.3–138 ng m−3, mean 39 ng m−3) than in spring (3.2–42 ng m−3, 15 ng m−3), while α/β-pinene and β-caryophyllene SOA tracers showed similar abundances between these two seasons. A strong positive correlation (R2 = 0.83) between levoglucosan and β-caryophyllinic acid was found in the spring samples vs. a weak correlation (R2 = 0.17) in the summer samples, implying substantial contributions from biomass burning to the β-caryophyllinic acid production in spring. Two organic nitrogen species (oxamic acid and carbamide) were detected in the aircraft aerosol samples, and their concentrations were comparable to those of biogenic SOA tracers. Most of the primary organic aerosol (POA) and SOA tracers were less abundant at higher altitudes, suggesting they are of ground surface origin, either being directly emitted from anthropogenic/natural sources on the ground surface, or rapidly formed through photooxidation of their precursors emitted from the ground surface and then diluted during uplifting into the troposphere. This study demonstrates that primary biological aerosols, biogenic SOA, and organic nitrogen species are important components of organic aerosols in the troposphere over central China during warm seasons.