bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioactive Natural Products of Marine Sponges from the Genus Hyrtios
Authors: Shady Nourhan , El-Hossary Ebaa , Fouad Mostafa , Gulder Tobias , Kamel Mohamed , Abdelmohsen Usama
Published: May 2017

Marine sponges are known as a rich source for novel bioactive compounds with valuable pharmacological potential. One of the most predominant sponge genera is Hyrtios, reported to have various species such as Hyrtios erectus, Hyrtios reticulatus, Hyrtios gumminae, Hyrtios communis, and Hyrtios tubulatus and a number of undescribed species. Members of the genus Hyrtios are a rich source of natural products with diverse and valuable biological activities, represented by different chemical classes including alkaloids, sesterterpenes and sesquiterpenes. This review covers the literature until June 2016, providing a complete survey of all compounds isolated from the genus Hyrtios with their corresponding biological activities whenever applicable.
Inclusion Complexes of a New Family of Non-Ionic Amphiphilic Dendrocalix[4]arene and Poorly Water-Soluble Drugs Naproxen and Ibuprofen
Authors: Khan Khalid , Badshah Syed , Ahmad Nasir , Rashid Haroon , Mabkhot Yahia
Published: May 2017

The inclusion complexes of a new family of nonionic amphiphilic calix[4]arenes with the anti-inflammatory hydrophobic drugs naproxen (NAP) and ibuprofen (IBP) were investigated. The effects of the alkyl chain’s length and the inner core of calix[4]arenes on the interaction of the two drugs with the calix[4]arenes were explored. The inclusion complexes of Amphiphiles 1a–c with NAP and IBP increased the solubility of these drugs in aqueous media. The interaction of 1a–c with the drugs in aqueous media was investigated through fluorescence, molecular modeling, and 1H-NMR analysis. TEM studies further supported the formation of inclusion complexes. The length of lipophilic alkyl chains and the intrinsic cyclic nature of cailx[4]arene derivatives 1a–c were found to have a significant impact on the solubility of NAP and IBP in pure water.
Magnetic Cationic Amylose Nanoparticles Used to Deliver Survivin-Small Interfering RNA for Gene Therapy of Hepatocellular Carcinoma In Vitro
Authors: Wu Zhuo , Xu Xiao-Lin , Zhang Jun-Zhao , Mao Xu-Hong , Xie Ming-Wei , Cheng Zi-Liang , Lu Lie-Jing , Duan Xiao-Hui , Zhang Li-Ming , Shen Jun
Published: May 2017

Amylose is a promising nanocarrier for gene delivery in terms of its good biocompatibility and high transfection efficiency. Small interfering RNA against survivin (survivin-siRNA) can cause tumor apoptosis by silencing a hepatocellular carcinoma (HCC)-specific gene at the messenger RNA level. In this study, we developed a new class of folate-functionalized, superparamagnetic iron oxide (SPIO)-loaded cationic amylose nanoparticles to deliver survivin-siRNA to HCC cells. The cellular uptake of nanocomplexes, cytotoxicity, cell apoptosis, and gene suppression mediated by siRNA-complexed nanoparticles were tested. The results demonstrated that folate-functionalized, SPIO-loaded cationic amylose nanoparticles can mediate a specific and safe cellular uptake of survivin-siRNA with high transfection efficiency, resulting in a robust survivin gene downregulation in HCC cells. The biocompatible complex of cationic amylose could be used as an efficient, rapid, and safe gene delivery vector. Upon SPIO loading, it holds a great promise as a theranostic carrier for gene therapy of HCC.
Study on the Mechanism of a Side Coupling Reaction during the Living Anionic Copolymerization of Styrene and 1-(Ethoxydimethylsilyphenyl)-1-phenylethylene (DPE-SiOEt)
Authors: Liu Pibo , Ma Hongwei , Shen Heyu , Han Li , Chang Shuang , Zang Long , Bian Yiyu , Bai Yu , Li Yang
Published: May 2017

A 1,1-diphenylethylene (DPE) derivative with an alkoxysilyl group (DPE-SiOEt) was synthesized. It was end-capped with poly(styryl)lithium (PSLi) and then copolymerized with styrene via living anionic polymerization (LAP) in a non-polar solvent at room temperature. The observed side coupling reaction was carefully investigated by end-capping the polymer. Changes in molecular weight support the plausibility of a mechanism involving living anionic species (PSLi or lithiated DPE-end-capped polystyrene, PSDLi) and the alkoxysilyl groups. Through a series of copolymerizations with different feed ratios, the kinetics of the side coupling reaction were also studied. The results showed that the side reactions could be controlled using an excess feed of DPE-SiOEt, a potentially useful strategy for the synthesis and application of well-defined alkoxysilyl-functionalized polymers via LAP.
An Automatic Shadow Detection Method for VHR Remote Sensing Orthoimagery
Authors: Wang Qiongjie , Yan Li , Yuan Qiangqiang , Ma Zhenling
Published: May 2017

The application potential of very high resolution (VHR) remote sensing imagery has been boosted by recent developments in the data acquisition and processing ability of aerial photogrammetry. However, shadows in images contribute to problems such as incomplete spectral information, lower intensity brightness, and fuzzy boundaries, which seriously affect the efficiency of the image interpretation. In this paper, to address these issues, a simple and automatic method of shadow detection is presented. The proposed method combines the advantages of the property-based and geometric-based methods to automatically detect the shadowed areas in VHR imagery. A geometric model of the scene and the solar position are used to delineate the shadowed and non-shadowed areas in the VHR image. A matting method is then applied to the image to refine the shadow mask. Different types of shadowed aerial orthoimages were used to verify the effectiveness of the proposed shadow detection method, and the results were compared with the results obtained by two state-of-the-art methods. The overall accuracy of the proposed method on the three tests was around 90%, confirming the effectiveness and robustness of the new method for detecting fine shadows, without any human input. The proposed method also performs better in detecting shadows in areas with water than the other two methods.
A Study of Pattern Prediction in the Monitoring Data of Earthen Ruins with the Internet of Things
Authors: Xiao Yun , Wang Xin , Eshragh Faezeh , Wang Xuanhong , Chen Xiaojiang , Fang Dingyi
Published: May 2017

An understanding of the changes of the rammed earth temperature of earthen ruins is important for protection of such ruins. To predict the rammed earth temperature pattern using the air temperature pattern of the monitoring data of earthen ruins, a pattern prediction method based on interesting pattern mining and correlation, called PPER, is proposed in this paper. PPER first finds the interesting patterns in the air temperature sequence and the rammed earth temperature sequence. To reduce the processing time, two pruning rules and a new data structure based on an R-tree are also proposed. Correlation rules between the air temperature patterns and the rammed earth temperature patterns are then mined. The correlation rules are merged into predictive rules for the rammed earth temperature pattern. Experiments were conducted to show the accuracy of the presented method and the power of the pruning rules. Moreover, the Ming Dynasty Great Wall dataset was used to examine the algorithm, and six predictive rules from the air temperature to rammed earth temperature based on the interesting patterns were obtained, with the average hit rate reaching 89.8%. The PPER and predictive rules will be useful for rammed earth temperature prediction in protection of earthen ruins.
Country Selection Model for Sustainable Construction Businesses Using Hybrid of Objective and Subjective Information
Authors: Lee Kang-Wook , Jung Wooyong , Han Seung
Published: May 2017

An important issue for international businesses and academia is selecting countries in which to expand in order to achieve entrepreneurial sustainability. This study develops a country selection model for sustainable construction businesses using both objective and subjective information. The objective information consists of 14 variables related to country risk and project performance in 32 countries over 25 years. This hybrid model applies subjective weighting from industrial experts to objective information using a fuzzy LinPreRa-based Analytic Hierarchy Process. The hybrid model yields a more accurate country selection compared to a purely objective information-based model in experienced countries. Interestingly, the hybrid model provides some different predictions with only subjective opinions in unexperienced countries, which implies that expert opinion is not always reliable. In addition, feedback from five experts in top international companies is used to validate the model’s completeness, effectiveness, generality, and applicability. The model is expected to aid decision makers in selecting better candidate countries that lead to sustainable business success.
Anomia and Displacement of Responsibility as Determinants of Tourist Company Managers’ Non-Involvement in Alleviating Poverty
Authors: Sánchez-Medina Agustín , Benítez-del-Rosario Juan , Blázquez-Santana Félix
Published: May 2017

The economic transformation produced by tourism sometimes has a positive influence on reducing poverty, but other times it does not. Discovering the reasons for this difference is highly relevant. In searching for these reasons, this study will focus on an important actor in tourism management, the manager. Specifically, the study will analyze how a certain negative mood state, anomia, influences the fact that managers do not consider it advisable for their companies to become involved in reducing poverty. The term future managers has been used as a proxy variable for managers. In addition, the study will also examine whether a moral disengagement mechanism, displacement of responsibility, is a mediator variable in this relationship. Covariance-based structural equation modeling was applied to a sample of 422 students in their last year of the Tourism degree at two universities, Las Palmas de Gran Canaria (Spain) and Ibn-Zohr-Agadir (Morocco). The results show that all the proposed hypotheses are supported.
Mitigation of Patulin in Fresh and Processed Foods and Beverages
Authors: Ioi J. , Zhou Ting , Tsao Rong , F. Marcone Massimo
Published: May 2017

Patulin is a mycotoxin of food safety concern. It is produced by numerous species of fungi growing on fruits and vegetables. Exposure to the toxin is connected to issues neurological, immunological, and gastrointestinal in nature. Regulatory agencies worldwide have established maximum allowable levels of 50 µg/kg in foods. Despite regulations, surveys continue to find patulin in commercial food and beverage products, in some cases, to exceed the maximum limits. Patulin content in food can be mitigated throughout the food processing chain. Proper handling, storage, and transportation of food can limit fungal growth and patulin production. Common processing techniques including pasteurisation, filtration, and fermentation all have an effect on patulin content in food but individually are not sufficient safety measures. Novel methods to remove or detoxify patulin have been reviewed. Non-thermal processing techniques such as high hydrostatic pressure, UV radiation, enzymatic degradation, binding to microorganisms, and chemical degradation all have potential but have not been optimised. Until further refinement of these methods, the hurdle approach to processing should be used where food safety is concerned. Future development should focus on determining the nature and safety of chemicals produced from the breakdown of patulin in treatment techniques.
Mechanism of Nitrogen Removal from Aqueous Solutions Using Natural Scoria
Authors: Dong Tianzi , Zhang Yuling , Su Xiaosi , Chen Zhiyu , Si Chaoqun
Published: May 2017

The efficiencies and mechanisms of nitrogen removal from groundwater by scoria were studied. When NH4+-N concentration was 0.5–10 mg/L, the removal was 96–89%. When NO2−-N concentration was 0.1–5 mg/L, the removal was 93–85%. When NO3−-N concentration was 30–150 mg/L, the removal was 85–70%. Additionally, van der Waals forces had a positive impact on the adsorption, which promoted NH4+-N adsorption. Ion exchange and dissolution did not exist. Functional groups of N-H, C-H, and C-N changed after adsorption. Overall, this study indicates that scoria is an ecologically friendly and safe material that can be utilized for groundwater purification to treat nitrogen-contaminated water.
Comparison of Spatial Interpolation Schemes for Rainfall Data and Application in Hydrological Modeling
Authors: Chen Tao , Ren Liliang , Yuan Fei , Yang Xiaoli , Jiang Shanhu , Tang Tiantian , Liu Yi , Zhao Chongxu , Zhang Liming
Published: May 2017

The spatial distribution of precipitation is an important aspect of water-related research. The use of different interpolation schemes in the same catchment may cause large differences and deviations from the actual spatial distribution of rainfall. Our study analyzes different methods of spatial rainfall interpolation at annual, daily, and hourly time scales to provide a comprehensive evaluation. An improved regression-based scheme is proposed using principal component regression with residual correction (PCRR) and is compared with inverse distance weighting (IDW) and multiple linear regression (MLR) interpolation methods. In this study, the meso-scale catchment of the Fuhe River in southeastern China was selected as a typical region. Furthermore, a hydrological model HEC-HMS was used to calculate streamflow and to evaluate the impact of rainfall interpolation methods on the results of the hydrological model. Results show that the PCRR method performed better than the other methods tested in the study and can effectively eliminate the interpolation anomalies caused by terrain differences between observation points and surrounding areas. Simulated streamflow showed different characteristics based on the mean, maximum, minimum, and peak flows. The results simulated by PCRR exhibited the lowest streamflow error and highest correlation with measured values at the daily time scale. The application of the PCRR method is found to be promising because it considers multicollinearity among variables.
Multiple factors influence population sex ratios in the Mojave Desert moss Syntrichia caninervis
Authors: Ekwealor Jenna T. B. , Payton Adam C. , Paasch Amber E. , Fisher Kirsten M. , McDaniel Stuart F.
Published: May 2017

PREMISE OF RESEARCH:

Natural populations of many mosses appear highly female‐biased based on the presence of reproductive structures. This bias could be caused by increased male mortality, lower male growth rate, or a higher threshold for achieving sexual maturity in males. Here we test these hypotheses using samples from two populations of the Mojave Desert moss Syntrichia caninervis.

METHODS:

We used double‐digest restriction‐site associated DNA (RAD) sequencing to identify candidate sex‐associated loci in a panel of sex‐expressing plants. Next, we used putative sex‐associated markers to identify the sex of individuals without sex structures.

KEY RESULTS:

We found a 17:1 patch‐level phenotypic female to male sex ratio in the higher elevation site (Wrightwood) and no sex expression at the low elevation site (Phelan). In contrast, on the basis of genetic data, we found a 2:1 female bias at the Wrightwood site and only females at the Phelan site. The relative area occupied by male and female genets was indistinguishable, but males were less genetically diverse.

CONCLUSIONS:

Our data suggest that both male‐biased mortality and sexual dimorphism in thresholds for sex expression could explain genetic and phenotypic sex ratio biases and that phenotypic sex expression alone over‐estimates the extent of actual sex ratio bias present in these two populations of S. caninervis.
Comparative Mapping and Targeted‐Capture Sequencing of the Gametocidal Loci in Aegilops sharonensis
Authors: Grewal Surbhi , Gardiner Laura‐Jayne , Ndreca Barbora , Knight Emilie , Moore Graham , King Ian P. , King Julie
Published: May 2017

Gametocidal (Gc) chromosomes or elements in species such as Aegilops sharonensis Eig are preferentially transmitted to the next generation through both the male and female gametes when introduced into wheat (Triticum aestivum L.). Furthermore, any genes, such as genes that control agronomically important traits, showing complete linkage with Gc elements, are also transmitted preferentially to the next generation without the need for selection. The mechanism for the preferential transmission of the Gc elements appears to occur by the induction of extensive chromosome damage in any gametes that lack the Gc chromosome in question. Previous studies on the mechanism of the Gc action in Ae. sharonensis indicates that at least two linked elements are involved. The first, the breaker element, induces chromosome breakage in gametes, which have lost the Gc elements while the second, the inhibitor element, prevents the chromosome breakage action of the breaker element in gametes which carry the Gc elements. In this study, we have used comparative genomic studies to map 54 single nucleotide polymorphism (SNP) markers in an Ae. sharonensis 4SshL introgression segment in wheat and have also identified 18 candidate genes in Ae. sharonensis for the breaker element through targeted sequencing of this 4SshL introgression segment. This valuable genomic resource will aide in further mapping the Gc locus that could be exploited in wheat breeding to produce new, superior varieties of wheat.
A New Spectral Feature on the Trailing Hemisphere of Europa at 3.78 μm
Authors: Trumbo Samantha K. , Brown Michael E. , Fischer Patrick D. , Hand Kevin P.
Published: May 2017

We present hemispherically resolved spectra of the surface of Europa from ∼3.1–4.13

, which we obtained using the near-infrared spectrometer NIRSPEC on the Keck II telescope. These include the first high-quality L-band spectra of the surface to extend beyond 4

. In our data, we identify a previously unseen spectral feature at 3.78

on the trailing hemisphere. The longitudinal distribution of the feature is consistent with that of a radiolytic product created by electron or Iogenic ion bombardment. This feature is coincident with an absorption feature of SO2 frost seen in both laboratory spectra and spectra of Io. However, the corresponding, typically stronger 4.07

feature of SO2 frost is absent from our data. This result is contrary to the suggested detection of SO2 at 4.05

in Galileo NIMS data of the trailing hemisphere, which was severely affected by radiation noise. We use simple spectral modeling to argue that the 3.78

feature is not easily explained by the presence of SO2 frost on the surface. We explore alternative explanations and discuss other potential candidate species.
Travailler la mémoire d’une révolte au xvii e siècle : le chanoine Moreau et le soulèvement bas-breton de 1490
Authors: Hamon Philippe
Published: May 2017

Au début du xvii e  siècle, le chanoine quimpérois Jean Moreau compose le récit d’une révolte survenue en basse Bretagne en 1490. Sa démarche érudite s’appuie sur des sources textuelles et orales. Il nous donne accès aux modalités de l’invention de traditions qui rejouent d’ailleurs ultérieurement. Mais ce récit, à la croisée des chemins mémoriels, a une fonction avant tout idéologique et non ethnographique. Moreau y dénonce les effets toujours désastreux d’une irruption collective des ruraux dans le cours de l’histoire. Sa prise de position exprime une vraie haine sociale et caricature les formes rurales de politisation pour leur dénier toute légitimité.
Une parole incontrôlée ? De la rhétorique de l’opposition aux mots de la rébellion des États de Bohême (1618-1620)
Authors: Richard Nicolas
Published: May 2017

Rarement analysé par les historiens des révoltes, parce qu’il ne fut ni spontané, ni populaire, ni appuyé sur une pensée politique originale, le soulèvement des états de Bohême (1618-1620) présente une qualité rare pour l’historien : sa banalité. Les nobles révoltés étaient en effet des gens rompus aux débats, houleux mais codifiés, de la diète du royaume. La défenestration, reprenait un rituel certes traditionnel dans le royaume, mais peu compréhensible dans une Europe sensible aux questions de la souveraineté. En revanche le discours ad extra (ménageant la majesté royale) et ad intra (le prophétisme protestant) était soigneusement contrôlé – peut-être trop, d’où un effet démobilisateur.
Non à la Glorieuse Révolution ! Les jacobites : entre défense de l’ordre établi et révolte
Authors: Rameix Solange
Published: May 2017

Dès l’arrivée en Angleterre de Guillaume d’Orange en 1688, la Glorieuse Révolution a été l’objet de multiples interprétations, souvent contradictoires puisque raconter l’événement c’est lui donner un sens, le légitimer ou, au contraire, le condamner. Immédiatement, les jacobites, partisans du roi déchu Jacques II, ont dénoncé la Glorieuse Révolution en utilisant une rhétorique biblique de défense du droit divin. Mais, dans les sources orangistes, ces défenseurs de l’ordre établi deviennent à leur tour des révoltés désobéissant à leur souverain légitime, Guillaume III. Les jacobites s’en offusquent peu et certains, des whigs jacobites, n’hésitent pas à se présenter eux-mêmes comme des révolutionnaires, porteurs des valeurs de 1688, même si, selon eux, Guillaume III a trahi leurs idéaux.
Orgon l’enthousiaste. Une critique du fanatisme ?
Authors: Dandrey Patrick
Published: May 2017

On propose d’interpréter la critique du fanatisme lisible en filigrane de la dévotion aveugle d’Orgon dans Tartuffe à la lumière des théories anglaises contemporaines sur la maladie ou la passion d’enthusiasm frappant les prophètes « inspirés » des sectes surgies ou réfugiées en terre britannique dans la 2e moitié du xvIIe siècle. Et d’éclairer les répréhensions de Cléante envers la fureur dévote d’Orgon à la lumière de la doctrine de la tolérance élaborée en réponse à ces épidémies d’enthousiasme. On tâche de tirer du parallèle avec ces thèses, portées notamment par Locke et Shaftesbury, des clartés sur l’anatomie du fanatisme et son éradication par le rire tels que la comédie de Molière les pratique.
Comprendre le vote pour le Brexit : de l’utilité d’une analyse territoriale
Authors: Bailoni Mark
Published: May 2017

Le vote pour le leave au référendum sur l’appartenance du Royaume-Uni à l’Union européenne (UE) est souvent décrit comme l’expression d’une révolte de classes populaires qui se sentent déclassées et délaissées par les forces politiques traditionnelles, une réaction anti-immigration dans un contexte de crise migratoire dans une Europe de la libre circulation, le rejet d’une UE trop technocratique et trop coûteuse pour le budget britannique, et l’affirmation d’un Royaume-Uni qui se perçoit encore comme une puissance de classe mondiale. Certes, ces éléments sont les motivations premières des électeurs du leave . Toutefois, pour comprendre les fondements et les origines de ce vote, il apparaît nécessaire de le contextualiser dans une approche territoriale, à une échelle nationale mais aussi à un niveau local, et dans les évolutions électorales récentes du pays et de quelques territoires locaux significatifs. En effet, le vote leave est certes l’expression d’un euroscepticisme britannique ancien et ancré, mais aussi la conséquence de certains ressentiments identitaires, d’une colère sociale et de certaines problématiques locales. L’analyse locale du vote est ainsi essentielle pour en comprendre les fondements, comme le montrent les exemples de ces espaces conflictuels à l’ouest de Londres, de Clacton ou de Boston.
Peut-on penser les finalités européennes sans la Russie ?
Authors: Thomann Pierre-Emmanuel
Published: May 2017

L’Union européenne se rapproche d’une puissance civile dans les relations internationales et cultive son propre modèle distinct de diplomatie et de gestion civilo-militaire. L’absence de réflexion géopolitique au sein de l’UE a pourtant pour conséquence une aggravation de ses relations avec la Russie dont les objectifs s’accordent mal à ceux de l’UE, et de sa propre sécurité dans le contexte d’un couple franco-allemand en panne après le Brexit.
À quoi croient nos élites ?
Authors: Koenig Gaspard
Published: May 2017

Les convictions intellectuelles et politiques partagées par l’élite sont déterminantes dans la structuration économique et sociale d’un pays. Force est de constater que l’élite française, longtemps attachée au libéralisme hérité de la Révolution, a développé depuis l’après-guerre une foi dans l’État qui explique le caractère planiste de la politique publique jusqu’à aujourd’hui. Il est temps de rompre avec cette pensée trop homogène et trop dirigiste.
Les grands serviteurs de l’État, une espèce en voie de disparition ?
Authors: Kessler David
Published: May 2017

La haute fonction publique française a longtemps été vue comme une élite dont les responsables étaient ceux qu’on appelait « les grands serviteurs de l’État ». Ils ont largement contribué à l’évolution de la France contemporaine. Le combat d’aujourd’hui, dirigé contre les élites, ne les épargne pas. S’ils en sont largement victimes, leurs postures ont pu aussi donner prise à la critique et à cette évolution. Si elle veut retrouver sa place et son prestige, c’est aussi à une réforme profonde de son recrutement et de son rôle que la haute fonction publique doit s’atteler.
De la nécessité de la sélection et de ses modalités
Authors: Bigorgne Laurent
Published: May 2017

En matière de sélection des élites, le modèle des conventions d’éducation prioritaire de Sciences Po n’a pas vraiment essaimé en France. Aujourd’hui, la matrice de formation de nos élites fait face à deux risques, se refermer sur elle-même socialement, d’une part, et intellectuellement si elle ne parvient pas à se réformer davantage, d’autre part. C’est du moins ce qui ressort d’une comparaison internationale systématique de nos performances en matière d’équité, mais aussi de nos performances dans la mondialisation. Faut-il donner raison au French-bashing ambiant quand il prétend que « les élites françaises n’ont pas été entraînées à réussir dans le monde mais dans le centre de Paris » ?
Migrations et relations interethniques dans la ville
Authors: Garnier Julie
Published: May 2017

« Autochtones et immigrés en quartier populaire. D’Aligre à l’Îlot Châlon » est le second ouvrage d’une série d’études conduites dans trois quartiers parisiens à la fin des années 1980, avec le soutien de la mission de la recherche urbaine du ministère de l’Urbanisme et du Logement. Publié en 1987 par Véronique De Rudder, en collaboration avec Michelle Guillon, l’ouvrage aborde la question des relations interethniques dans la ville en partant du postulat que toutes les situations résidentielles urbaines sont des situations de « cohabitation pluriethnique ». Cette situation de cohabitation, « loin de former un système dichotomique, est construite par des relations « entre des groupes multiples, fluctuants, difficiles à définir avec précision, traversés de multiples clivages » (J. Mantovani et O. Saint-Raymond (1984) cité par De Rudder, 1990, p. 70).
D’Abdelmalek Sayad à aujourd’hui : revisiter les « âges » de l’émigration algérienne
Authors: Lacroix Thomas , Lemoux Julie
Published: May 2017

Au début des années 1970, la sociologie d’Abdelmalek Sayad rompt avec les études précédentes portant sur les migrations internationales. Ses travaux offrent un regard plus humanisant sur l’immigré algérien dans un contexte marqué par les divers bouleversements liés au processus de décolonisation. Sa pensée renouvelle la vision d’un phénomène qui a survécu aux aléas des relations franco-algériennes, notamment en matière de politique migratoire. Cet article propose de revisiter une des contributions fondamentales de Sayad, aussi bien pour mettre en lumière les éléments de continuité que les recompositions (profils des émigrés, motifs et conditions de départ, destinations) qui structurent le champ migratoire algérien depuis les années 1990 et 2000. À partir d’une approche en termes de « générations d’émigrés », il s’agit d’analyser la « nouveauté » qui caractérise depuis les années 2000 le paysage migratoire algérien comme le produit des mutations contemporaines, tant du côté du pays d’origine que des pays d’immigration. Cet article se propose d’évaluer la pertinence, mais aussi les limites que peut avoir l’approche de Sayad aujourd’hui.
Le Master Migrations internationales, espaces et sociétés à Poitiers
Authors: Lessault David , Miranda Adelina , Lassailly-Jacob Véronique
Published: May 2017

Ce texte propose une synthèse des communications sur l’enseignement des migrations proposées au colloque des 30 ans de l’UMR Migrinter par Véronique Lassailly-Jacob sur les origines et l’histoire du Master à Poitiers (France), Pierre Kamdem sur la création d’un Master professionnel sur les relations « Migrations et développement » à Dschang (Cameroun) et Papa Sakho sur le développement du Master « Migrations Internationales, Développement et Relations Interculturelles » (MIRI) de Dakar (Sénégal). Ces trois interventions, complétées par les réflexions de David Lessault, responsable du Master « Migrations internationales, espaces et sociétés » (Poitiers) de 2013 à 2016 et Adelina Miranda, actuelle co-responsable avec Christophe Imbert, structurent le propos. Les auteurs soulignent les fondements théoriques et les grandes évolutions pédagogiques du Master migrations internationales de Poitiers et soulèvent finalement le défi et les difficultés actuelles de son internationalisation, notamment par le biais de coopérations universitaires avec des partenaires africains.
Analytical study on lateral torsional buckling of partially encased beams under ISO834 fire exposure
Authors: Ramos-Gavilán Ana Belén , Piloto Paulo , Mesquita Luís
Published: May 2017

European standard EN1994-1-2:2005 provides tabulated values and simplified calculation models for assessing fire resistance of composite beams, but does not consider the design checks against lateral torsional buckling under fire. This research presents an analytical method to calculate the buckling resistance moment of laterally unrestrained partially encased beams in fire conditions. The proposal applies a reduction factor for lateral torsional buckling in fire design condition to the moment resistance of the homogenised section at time t, determined by EN1994-1-2:2005. Two finite element models capable to simulate the thermal and mechanical behaviour of partially encased beams are also presented, including the validation against fire tests conducted by Piloto et al. Based on these models, a numerical analysis of partially encased beams with the same geometry and material properties as used in experimental tests is presented, evaluating different load levels when exposed to standard fire ISO834:1999. The numerical results of fire resistance according to standard EN1363- 1:2012 and the numerical ultimate time, when beams suffer instability, are used to validate the proposal, using experimental and analytical heating result according to EN1994-1-2:2005.
Paediatric gastrointestinal volvulus: Twisting our heads around unusual diagnoses
Authors: Hanekom Heleen , Pillay Tanyia , Harrison Derek , Minnis Talietha
Published: May 2017

No abstract available.
Weak Factorizations of the Hardy Space H1(ℝn) in Terms of Multilinear Riesz Transforms
Authors: Li Ji , Wick Brett D.
Published: May 2017

This paper provides a constructive proof of the weak factorization of the classical Hardy space H1(ℝn) in terms of multilinear Riesz transforms. As a direct application, we obtain a new proof of the characterization of BMO(ℝn) (the dual of H1(ℝn)) via commutators of the multilinear Riesz transforms.
Clouds over the summertime Sahara: an evaluation of Met Office retrievals from Meteosat Second Generation using airborne remote sensing
Authors: Kealy John C. , Marenco Franco , Marsham John H. , Garcia-Carreras Luis , Francis Pete N. , Cooke Michael C. , Hocking James
Published: May 2017

Abstract. Novel methods of cloud detection are applied to airborne remote sensing observations from the unique Fennec aircraft dataset, to evaluate the Met Office-derived products on cloud properties over the Sahara based on the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on-board the Meteosat Second Generation (MSG) satellite. Two cloud mask configurations are considered, as well as the retrievals of cloud-top height (CTH), and these products are compared to airborne cloud remote sensing products acquired during the Fennec campaign in June 2011 and June 2012. Most detected clouds (67 % of the total) have a horizontal extent that is smaller than a SEVIRI pixel (3 km  ×  3 km). We show that, when partially cloud-contaminated pixels are included, a match between the SEVIRI and aircraft datasets is found in 80 ± 8 % of the pixels. Moreover, under clear skies the datasets are shown to agree for more than 90 % of the pixels. The mean cloud field, derived from the satellite cloud mask acquired during the Fennec flights, shows that areas of high surface albedo and orography are preferred sites for Saharan cloud cover, consistent with published theories. Cloud-top height retrievals however show large discrepancies over the region, which are ascribed to limiting factors such as the cloud horizontal extent, the derived effective cloud amount, and the absorption by mineral dust. The results of the CTH analysis presented here may also have further-reaching implications for the techniques employed by other satellite applications facilities across the world.
Carbon monoxide column retrieval for clear-sky and cloudy atmospheres: a full-mission data set from SCIAMACHY 2.3  µm reflectance measurements
Authors: Borsdorff Tobias , aan de Brugh Joost , Hu Haili , Nédélec Philippe , Aben Ilse , Landgraf Jochen
Published: May 2017

Abstract. We discuss the retrieval of carbon monoxide (CO) vertical column densities from clear-sky and cloud contaminated 2311–2338 nm reflectance spectra measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) from January 2003 until the end of the mission in April 2012. These data were processed with the Shortwave Infrared CO Retrieval algorithm (SICOR) that we developed for the operational data processing of the Tropospheric Monitoring Instrument (TROPOMI) that will be launched on ESA's Sentinel-5 Precursor (S5P) mission. This study complements previous work that was limited to clear-sky observations over land. Over the oceans, CO is estimated from cloudy-sky measurements only, which is an important addition to the SCIAMACHY clear-sky CO data set as shown by NDACC and TCCON measurements at coastal sites. For Ny-Ålesund, Lauder, Mauna Loa and Reunion, a validation of SCIAMACHY clear-sky retrievals is not meaningful because of the high retrieval noise and the few collocations at these sites. The situation improves significantly when considering cloudy-sky observations, where we find a low mean bias b = ±6. 0 ppb and a strong correlation between the validation and the SCIAMACHY results with a mean Pearson correlation coefficient r = 0. 7. Also for land observations, cloudy-sky CO retrievals present an interesting complement to the clear-sky data set. For example, at the cities Tehran and Beijing the agreement of SCIAMACHY clear-sky CO observations with MOZAIC/IAGOS airborne measurements is poor with a mean bias of b = 171. 2 ppb and 57.9 ppb because of local CO pollution, which cannot be captured by SCIAMACHY. For cloudy-sky retrievals, the validation improves significantly. Here the retrieved column is mainly sensitive to CO above the cloud and so not affected by the strong local surface emissions. Adjusting the MOZAIC/IAGOS measurements to the vertical sensitivity of the retrieval, the mean bias adds up to b = 52. 3 ppb and 5.0 ppb for Tehran and Beijing. At the less urbanised region around the airport Windhoek, local CO pollution is less prominent and so MOZAIC/IAGOS measurements agree well with SCIAMACHY clear-sky retrievals with a mean bias of b = 15. 5 ppb, but can be even further improved for cloudy SCIAMACHY observations with a mean bias of b = 0. 2 ppb. Overall the cloudy-sky CO retrievals from SCIAMACHY short-wave infrared measurements present a major extension of the clear-sky-only data set, which more than triples the amount of data and adds unique observations over the oceans. Moreover, the study represents the first application of the S5P algorithm for operational CO data processing on cloudy observations prior to the launch of the S5P mission.
Minimum variance projection for direct measurements of power-law spectra in the wavenumber domain
Authors: Narita Yasuhito , Nishimura Yoshihiro , Hada Tohru
Published: May 2017

Abstract. Minimum variance projection is widely used in geophysical and space plasma measurements to identify the wave propagation direction and the wavenumber of the wave fields. The advantage of the minimum variance projection is its ability to estimate the energy spectra directly in the wavenumber domain using only a limited number of spatial samplings. While the minimum variance projection is constructed for discrete signals in the data, we find that the minimum variance projection can reasonably reproduce the spectral slope of the power-law spectrum if the data represent continuous power-law signals. The spectral slope study using the minimum variance projection is tested against synthetic random data with a power-law spectrum. The method is applicable even for a small number of spatial samplings. Conversely, the spatial aliasing causes a flattening of the spectrum.
Latest Permian carbonate-carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation
Authors: Schobben Martin , van de Velde Sebastiaan , Suchocka Jana , Leda Lucyna , Korn Dieter , Struck Ulrich , Ullmann Clemens Vinzenz , Hairapetian Vachik , Ghaderi Abbas , Korte Christoph , Newton Robert J. , Poulton Simon W. , Wignall Paul B.
Published: May 2017

Abstract. Bulk-carbonate carbon isotope measurements are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian–Triassic boundary in marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub)seafloor microbial communities and their control on calcite nucleation as well as on ambient porewater dissolved inorganic carbon-δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization, and linked carbon isotope alteration, can be controlled by organic matter supply and subsequent microbial remineralization. Low marine sulfate and a major biotic decline among late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation, causing varying degrees of carbon isotope overprint. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to one out of 10 samples, is sufficient to induce the observed signal of carbon isotope variability. These findings put constraints on the application of Permian–Triassic carbon isotope chemostratigraphy based on whole-rock samples, which appears less refined than classical biozonation dating schemes. On the other hand, this signal of increased carbon isotope variability concurrent with the largest mass extinction of the Phanerozoic may inform about local carbon cycling mediated by spatially heterogeneous (sub)-seafloor microbial communities under suppressed bioturbation.
Riverbank filtration for the treatment of highly turbid Colombian rivers
Authors: Gutiérrez Juan Pablo , van Halem Doris , Rietveld Luuk
Published: May 2017

Abstract. The poor quality of many Colombian surface waters forces us to seek alternative, sustainable treatment solutions with the ability to manage peak pollution events and to guarantee the uninterrupted provision of safe drinking water to the population. This review assesses the potential of using riverbank filtration (RBF) for the highly turbid and contaminated waters in Colombia, emphasizing water quality improvement and the influence of clogging by suspended solids. The suspended sediments may be favorable for the improvement of the water quality, but they may also reduce the production yield capacity. The cake layer must be balanced by scouring in order for an RBF system to be sustainable. The infiltration rate must remain high enough throughout the river–aquifer interface to provide the water quantity needed, and the residence time of the contaminants must be sufficient to ensure adequate water quality. In general, RBF seems to be a technology appropriate for use in highly turbid and contaminated surface rivers in Colombia, where improvements are expected due to the removal of turbidity, pathogens and to a lesser extent inorganics, organic matter and micro-pollutants. RBF has the potential to mitigate shock loads, thus leading to the prevention of shutdowns of surface water treatment plants. In addition, RBF, as an alternative pretreatment step, may provide an important reduction in chemical consumption, considerably simplifying the operation of the existing treatment processes. However, clogging and self-cleansing issues must be studied deeper in the context of these highly turbid waters to evaluate the potential loss of abstraction capacity yield as well as the development of different redox zones for efficient contaminant removal.
Advancing land surface model development with satellite-based Earth observations
Authors: Orth Rene , Dutra Emanuel , Trigo Isabel F. , Balsamo Gianpaolo
Published: May 2017

Abstract. The land surface forms an essential part of the climate system. It interacts with the atmosphere through the exchange of water and energy and hence influences weather and climate, as well as their predictability. Correspondingly, the land surface model (LSM) is an essential part of any weather forecasting system. LSMs rely on partly poorly constrained parameters, due to sparse land surface observations. With the use of newly available land surface temperature observations, we show in this study that novel satellite-derived datasets help improve LSM configuration, and hence can contribute to improved weather predictability. We use the Hydrology Tiled ECMWF Scheme of Surface Exchanges over Land (HTESSEL) and validate it comprehensively against an array of Earth observation reference datasets, including the new land surface temperature product. This reveals satisfactory model performance in terms of hydrology but poor performance in terms of land surface temperature. This is due to inconsistencies of process representations in the model as identified from an analysis of perturbed parameter simulations. We show that HTESSEL can be more robustly calibrated with multiple instead of single reference datasets as this mitigates the impact of the structural inconsistencies. Finally, performing coupled global weather forecasts, we find that a more robust calibration of HTESSEL also contributes to improved weather forecast skills. In summary, new satellite-based Earth observations are shown to enhance the multi-dataset calibration of LSMs, thereby improving the representation of insufficiently captured processes, advancing weather predictability, and understanding of climate system feedbacks.
Numerical modeling of the 2013 meteorite entry in Lake Chebarkul, Russia
Authors: Kozelkov Andrey , Kurkin Andrey , Pelinovsky Efim , Kurulin Vadim , Tyatyushkina Elena
Published: May 2017

Abstract. The results of the numerical simulation of possible hydrodynamic perturbations in Lake Chebarkul (Russia) as a consequence of the meteorite fall of 2013 (15 February) are presented. The numerical modeling is based on the Navier–Stokes equations for a two-phase fluid. The results of the simulation of a meteorite entering the water at an angle of 20° are given. Numerical experiments are carried out both when the lake is covered with ice and when it is not. The estimation of size of the destructed ice cover is made. It is shown that the size of the observed ice hole at the place of the meteorite fall is in good agreement with the theoretical predictions, as well as with other estimates. The heights of tsunami waves generated by a small meteorite entering the lake are small enough (a few centimeters) according to the estimations. However, the danger of a tsunami of meteorite or asteroid origin should not be underestimated.
The Brazilian Spring: Reconsidering Risk Assessment in Business and the Global Political Economy
Authors: Gouvea Raul , Kapelianis Dimitri , Montoya Manuel
Published: May 2017

In June of 2013, Brazil saw a massive outbreak of public protests and demonstrations. The government‟s apathy in responding to demands for greater transparency and enhanced levels of public services, as well as increasing levels of corruption and opacity, lead to these public uprisings. This paper argued that emerging economies with a growing middle class, particularly those that do not pay heed to this emerging class and their needs, are bound to face “spring-type” events. Utilizing a case study “quadruple helix” framework, this paper conducted an institutional analysis of the Brazilian “Spring” movement. This analysis yielded a considerable set of descriptions that can enhance the way that “spring-type” events influence business, policy, and economic behavior. More specifically, this research contributed an institutional approach to scholarship on risk analysis and geo-political unrest, establishing new trajectories for future scholarship that places risk analysis in the context of international management and world political economy.
Weakness in HK Currency Board System and Trading Opportunities in Betting A De-Peg of the Hong Kong Dollar
Authors: Li Kun
Published: May 2017

Hong Kong (HK) adopted the Linked Exchange Rate (LER) system in 1983, and it has been operating successfully for more than three decades. However, the maintenance costs for the LER system have grown exorbitantly and could outpace the costs of an exit, especially under the combined influence of a slow-down of the Chinese economy and a possible interest rate hike in the U.S. The HK government currently holds much more foreign reserves than it did preceding the 1997 Asian Financial Crisis. The HK government is also facing political unrest and growing anger of low income residents towards wealth inequality. This opposition could eventually force the HK government to abandon the Currency Board System. At present, the cost of exiting the LER ­system is small thanks to a strong HKD sustained by large capital inflows from mainland China. However, the time frame for such a low-cost exit is short.In our view, the HK government is likely to maintain the current system, even at high social and economic costs, in the expectation that changing external factors, such as the rebound of the Chinese economy, will relieve the de-pegging pressure. In this report, we explore several approaches to gauge the timing and risks of a de-pegging of the HKD and the collapse of the Chinese housing bubble. At the same time, we analyze the potential impact of a de-pegging on HK’s local companies and the most vulnerable parts of the system.