bluuebunny/crossref_metadata_2025 huggingface dataset:
Adipose-derived Mesenchymal Stem Cells and Arthroscopic Surgery
Authors: Moorman Claude T , Owusu-Akyaw Kwadwo A , Godin Jonathan , Pecchia Stefano , Oldweiler Alexander
Published: July 2017

Mesenchymal stem cells (MSCs) are multipotent cells with potential reparative properties for connective tissues, such as articular cartilage. The Lipogems adipose graft harvest system is a relatively novel technique for harvesting adipose-derived MSCs and may be utilized in conjunction with various orthopaedic sports medicine procedures.

Owusu-Akyaw KA, Godin J, Pecchia S, Oldweiler A, Moorman CT. Adipose-derived Mesenchymal Stem Cells and Arthroscopic Surgery. The Duke Orthop J 2017;7(1):34-38.
Novel Use of a Trabecular Metal Augment in a Severe Acetabular Defect
Authors: Bolognesi Michael P , Jennings Jason M , Scott Daniel J
Published: July 2017

Many total hip arthroplasties are complicated by severe acetabular bone loss, limiting reconstruction options. This case report details the use of a 54-mm trabecular metal straight buttress and press-fit jumbo cup to reconstruct an especially large superior and medial defect (Paprosky type IIIB). Specifically, the large defect was reconstructed by placing the augment superior-medially in the acetabular defect instead of simply superiorly and attached to the iliac wing as it is more commonly employed. To our knowledge, there has been no reported use of a similar augment to fill such a defect in this way. This technique represents a promising potential option for reconstruction of especially large superior and medial acetabular defects

Scott DJ, Jennings JM, Bolognesi MP. Novel Use of a Trabecular Metal Augment in a Severe Acetabular Defect. The Duke Orthop J 2017;7(1):39-42.
Ultrasound-guided Cubital Tunnel Injection: Description of Technique and Accuracy in a Cadaver Model
Authors: Richard Marc J , Leversedge Fraser J , Ruch David S , Nickel Brian T , Cotterell Ilvy , Crosmer Megan
Published: July 2017

Introduction:

Ulnar nerve (UN) and cubital tunnel morphology is influenced by elbow positioning, potentially compromising injection accuracy and placing the nerve at risk during cubital tunnel injection.

Materials and methods:

Based on previous anatomical studies of the cubital tunnel, a proof of concept injection model was developed. Eighteen above-elbow cadaver specimens were positioned in 45° elbow flexion and in neutral forearm rotation. The ultrasound transducer was oriented in the transverse plane, in-line with the medial epicondyle and olecranon tip, facilitating visualization of the UN and cubital tunnel. A 25-gauge needle oriented parallel to the ulna was inserted percutaneously at the midpoint between olecranon and epicondyle. The needle was advanced under ultrasound guidance to replicate injection and was secured. Open dissection confirmed its location.

Results:

18/18 needle tips were within the cubital tunnel and no needles penetrated the UN.

Discussion:

Ultrasound-guided cubital tunnel injection, with the elbow in 45° flexion and with neutral forearm rotation was a safe and reliable technique in this cadaveric model. Future clinical studies may evaluate the efficacy of both diagnostic and therapeutic cubital tunnel injection.

Nickel BT, Richard MJ, Cotterell I, Crosmer M, Ruch DS, Leversedge FJ. Ultrasound-guided Cubital Tunnel Injection: Description of Technique and Accuracy in a Cadaver Model. The Duke Orthop J 2017;7(1):43-45.
Screening for Functional Cognition in Postacute Care and the Improving Medicare Post-Acute Care Transformation (IMPACT) Act of 2014
Authors: Giles Gordon Muir , Edwards Dorothy Farrar , Morrison M. Tracy , Baum Carolyn , Wolf Timothy J.
Published: July 2017

Occupational therapists have a long history of assessing functional cognition, defined as the ability to use and integrate thinking and performance skills to accomplish complex everyday activities. In response to passage of the Improving Medicare Post-Acute Care Transformation (IMPACT) Act of 2014 (Pub. L. 113–185), the American Occupational Therapy Association has been advocating that the Centers for Medicare and Medicaid Services consider functional cognition for inclusion in routine patient assessment in postacute care settings, with important implications for occupational therapy. These efforts have the potential to increase referrals to occupational therapy, emphasize the importance of addressing functional cognition in occupational therapy practice, and support the value of occupational therapy in achieving optimal postacute care outcomes.
The Impact of Non-uniform Sampling on Stratospheric Ozone Trends Derived from Occultation Instruments
Authors: Damadeo Robert P. , Zawodny Joseph M. , Remsberg Ellis E. , Walker Kaley A.
Published: July 2017

Abstract. This paper applies a recently developed technique for deriving long-term trends in ozone from sparsely sampled data sets to multiple occultation instruments simultaneously without the need for homogenization. The technique can compensate for the non-uniform temporal, spatial, and diurnal sampling of the different instruments and can also be used to account for biases and drifts between instruments. These problems have been noted in recent international assessments as being a primary source of uncertainty that clouds the significance of derived trends. Results show potential recovery trends of ~ 2–3 %/decade in the upper stratosphere at mid-latitudes, which are similar to other studies, and also how sampling biases present in these data sets can create differences in derived "recovery" trends of up to ~ 1 %/decade if not properly accounted for. Limitations inherent to all techniques (e.g., relative instrument drifts) and their impacts (e.g., trend differences up to ~ 2 %/decade) are also described and a potential path forward towards resolution is presented.
Gas enclosure in polar firn follows universal law
Authors: Schaller Christoph Florian , Freitag Johannes , Eisen Olaf
Published: July 2017

Abstract. In order to interpret the paleoclimatic record stored in the air enclosed in polar ice cores, it is crucial to understand the fundamental lock-in process. Within the porous firn, bubbles are sealed continuously until the respective horizontal layer reaches a critical porosity. Present-day firn models use a postulated temperature dependence of this value as the only parameter to adjust to the surrounding conditions of individual sites. However, no direct measurements of the firn microstructure could confirm these assumptions. Here we show that the critical porosity is a universal constant by providing a statistically solid data set of μm-resolution 3D X-ray computer tomographic measurements for ice cores representing different extremes of the temperature and accumulation ranges. We demonstrate why indirect measurements yield misleading data and substantiate our observations by applying percolation theory as a theoretical framework for bubble trapping. Incorporation of our results does significantly influence the dating of trace gas records, changing gas age–ice age differences by up to more than 1000 years. This will help resolve inconsistencies, such as differences between East Antarctic δ15N records (as a proxy for firn height) and model results. We expect our findings to be the basis for improved firn air and densification models, leading to lower dating uncertainties. The reduced coupling of proxies and surrounding conditions may allow for more sophisticated reinterpretations of trace gas records in terms of paleoclimatic changes and will foster the development of new proxies, such as the air content as a marker of local insolation.
The role of organizational culture in policy mobilities – the case of South Korean climate change adaptation policies
Authors: Schäfer Susann
Published: July 2017

Abstract. The conceptualization of policies as mobile and mutable knowledge is the key feature of the recent debate on policy mobilities. Policy mobility studies have focused on the movement and translation of policies as well as on the impact of mobile policies on policy-making processes and governed spaces. Given that policy mobilities have mainly been examined in comparable institutional contexts, the current debate has neglected the role of organizational culture in the translation of policies. Organizational culture is understood as a set of shared assumptions that guide what happens in organizations by defining appropriate practices of policy making. The case study, South Korean adaptation policy, illustrates that organizational culture has a significant impact on the translation of mobile adaptation policy. Besides the claim to consider organizational culture more prominently in the field of policy mobility studies, this paper illustrates the translation process of adaptation policy in the South Korean political system. The practices in South Korean political institutions dealing with climate change adaptation are highly characterized by the avoidance of risks. The propensity to avoid risks leads policy makers to focus on technical solutions to climate change adaptation and to neglect the participation of civil society.
Testimony, Memory and Solidarity across National Borders: Paul Ricoeur and Transnational Feminism
Authors: Purcell Elizabeth
Published: July 2017

In many ways, globalization created the problem of representation for feminist solidarity across the borders of the nation state. This problem is one of presenting a cohesive identity for representation in the transnational public sphere. This paper proposes a solution to this problem of a cohesive identity for women’s representation by drawing on the work of Paul Ricœur. What these women seem to have in common are shared political aims, but they have no basis for those aims. This paper provides a basis for these aims by turning to Ricœur’s work on collective memory from Memory, History, Forgetting. The paper concludes that it is the shared testimony through narrative hospitality, which can provide a foundation for a social bond for those with common political aims. More specifically, this common knowledge provides a justification for the representation of women and their allies in the transnational public sphere.
Miguel de Unamuno: La feminización de la masculinidad moderna
Authors: Díaz Freire José Javier
Published: July 2017

Miguel de Unamuno y Ortega discreparon durante el primer tercio del siglo XX sobre el proceso de modernización que se estaba produciendo en España. Ambos lo interpretaron en términos de género. Pero mientras Ortega vinculaba la crisis de la modernidad con un déficit de masculinidad, Unamuno entendía que la deshumanización del mundo moderno se debía a una conformación inadecuada de la feminidad y de la masculinidad de la época, que cabía corregir feminizando la modernidad. Para ello emprendió una intensa labor de crítica de las relaciones de género en su obra dramática y novelesca que era también una propuesta de construcción de una modernidad alternativa.
El imperio interno: Discursos sobre masculinidad e imperio en los imaginarios nacionales español y catalán del siglo XX
Authors: Miguélez-Carballeira Helena
Published: July 2017

Este artículo parte de la idea de que la imaginación post-imperial española después de 1898 englobaba también la temática de los separatismos periféricos, así como la idea de que el proceso de desintegración nacional representaba la fase última del declive imperial español. El artículo analiza la presencia de este imaginario imperial interno en España invertebrada (1922) de Ortega y Gasset, así como sus reverberaciones en los ensayos de Ernesto Giménez Caballero y de Jaume Vicens Vives sobre las relaciones entre Castilla y Cataluña, que interactuaban de modo explícito con España invertebrada. Además, el artículo analiza el juego de poder competitivo que subyace a los imaginarios de la nación español y catalán a lo largo del siglo XX, donde la evocación simbólica del imperio ha funcionado como una anhelada marca de poder masculino, presente en las diferentes propuestas de solución política al conflicto nacional interno.
El escritor Nicomedes-Pastor Díaz en el entramado político-financiero de mediados del siglo XIX
Authors: Fernández-Sanguino Fernández Julio
Published: July 2017

Nicomedes-Pastor Díaz Corbelle (Viveiro, 1811 - Madrid, 1863) ha pasado a la posteridad como notable escritor y político liberal-conservador de mediados del siglo XIX; sin embargo, su sensible papel en algunos momentos de la política española no ha sido suficientemente indagado, al igual que su destacada participación en el lobby político-financiero que se formó en la Década Moderada no se suele tener en cuenta en sus biografías. Esta última cuestión es el objetivo principal del presente estudio, centrado en una etapa histórica en la que, además de las regresiones en las libertades ciudadanas, se generarían actuaciones promovidas por grupos en el poder tendentes a enriquecimientos indebidos, todo ello en un contexto económico en el que se producirían irregularidades y crisis similares a las habidas recientemente en nuestro país.
Los intelectuales españoles ante los acontecimientos de Marruecos en 1911. (Un episodio en la crítica o inclinación de España hacia Francia)
Authors: García de Juan Miguel Ángel
Published: July 2017

Las acciones y manifestaciones de fuerza militares en Marruecos en 1911 por parte de Francia, España y Alemania estuvieron a punto de provocar un conflicto armado internacional. Cada país de los citados acusó al otro de haber ido a Fez, Larache Alcazarquivir o Agadir con el pretexto de socorrer a sus protegidos. Los intelectuales españoles tomaron partido mayoritariamente contra la primera en sus colaboraciones periodísticas, fuente principal del presente trabajo. La aportación de éste radica en recordar lo sucedido en aquel crucial 1911, pues la historiografía española ha pasado, en gran parte, con demasiada rapidez sobre ello. Con todo, su primordial fin es reflejar, a partir de la prensa, un episodio más de las discrepancias entre Francia y España, ahora con ocasión de las intervenciones en el norte de África, al cual se ha prestado muy poca o ninguna atención. Por otro lado, cabe poner de relieve que la falta de criterio común en las opiniones de los intelectuales provocó en ciertos casos alguna agria discusión.
A la nación por la clase. La campaña electoral socialista de noviembre de 1933
Authors: Martí Bataller Aurelio
Published: July 2017

El artículo analiza la campaña electoral realizada por el Partido Socialista Obrero Español para las elecciones de noviembre del 1933. A partir de la importancia que la nueva historia sociocultural y política atribuye a los discursos en la conformación de las identidades y la acción colectiva, el artículo intenta poner de manifiesto la capital importancia que tuvo el uso de la narrativa nacional por parte del socialismo. Con ello, se trata de llamar la atención sobre una vía central en la (re)construcción y difusión social de la identidad nacional española, como los procesos de politización y el rol que el socialismo pudo jugar a tal efecto.
Water Transfer by Tangential Line Method - A Suggestion to Solve All Kinds of Water Related Problems in the World
Authors: Mohan T. Bharathi
Published: July 2017

I would like to extend my idea in this article to over come the first and foremost need of lives which till now exists in the planet earth and no authenticated news of availability in any other planet -WATER and its Conservation.From the water rich sources, we can transfer the water from one place to another without using electricity. This is possible by fixing the pipe lines parallel to the tangential line of the Earth Circle.
Examining the Relationship between Teachers’ Individual Innovativeness and Professionalism
Authors: Parlar Hanifi , Cansoy Ramazan
Published: July 2017

The aim of this study was to examine the relationship between teachers’ individual innovativeness and their teacher professionalism. The participants were 567 teachers working in elementary, middle and high schools located across Istanbul. The data were gathered through the "Individual Innovativeness Scale" and the "Teacher Professionalism Scale". In data analysis, arithmetic means and Pearson Product-Moment Correlation Analysis were used. The results of the study showed that the teachers’ characteristics of individual innovativeness fell into the group of early majority. The teachers’ innovativeness was found to be at the highest level in the dimension of openness to experience. There was a weak positive relationship between the individual innovativeness characteristics of openness to experience and opinion-leading, and teacher professionalism, which was significant.
Reviewer Acknowledgements for Journal of Sustainable Development, Vol. 10, No. 4
Authors: Sun Sherry
Published: July 2017

Reviewer Acknowledgements for Journal of Sustainable Development, Vol. 10, No. 4, 2017
STUDY ON MONGOLIAN FOREST STAND DYNAMICS USING MATHEMATICAL MODELING
Authors: M Khulan , Junchang Liu
Published: July 2017

A Global warming, climate change and negative human activities are expected to directly and negatively influence Mongolia’s forest resource area and quality [21]. In 2015, Mongolian forested area was 12,188.2 thousand hectare and in compared with the forested area in 2010, it has decreased by 864.5 thousand hectare. The important causes of deforestation and forest degradation are fire, improper commercial logging, illegal collection of wood for construction and fuel wood, overgrazing, mining activity, and damage by pests and diseases. Mongolian forest stand is not only decreasing in quantity, but also forest age class has been changing into maturity forest classification in recent years. The maturity forest resource has counted for 74 percent of total forest resource is in National Forest Inventory, 2016. There are few study for Mongolian forest stand dynamics and this work is first research that used stochastic process to predict forest stand dynamics in Mongolian case. This paper considered the main factors such as Climate factors and Socio-Economic factors in predicting forest stand dynamics. The factors are chosen based on real situation of forest resource’s changes in Mongolia. The study has estimated coefficients of relationship between forest resource and main factors, as well as main factors and their explanatory variables, using suitable regression model for all estimation. Moreover, Markov chain process has been used to extracted future dynamic of forest stand by age class structure based on imbalanced age structure of total forest resource today. The result of this paper shows that the most important factors that influenced the future forest stand changes are forest fire, commercial logging and afforestation. The estimated model results shows the forest fire will be decreased (9%), commercial logging will be increased (25%) and reforestation will be increased (30%) by 2030. Specially, this paper presented that forest resource will be decreased by 13 percent in future 15 years. Additionally, this decrease is consist of forest age structure changes which is young aged forest would be increased by 27%, middle aged forest would be decreased by 15%, maturing forest would be decreased by 39% and maturity forest would be decreased by 16% in 2030.
ADDITIONS TO THE VASCULAR FLORA OF MONGOLIA - III
Authors: M Urgamal , B Oyuntsetseg , V Gundegmaa , T Munkh-Erdene , Kh Solongo
Published: July 2017

The paper presents the updates on the new species; new regional and new location records since the treatment for “Conspectus of the vascular plants of Mongolia” (Urgamal et al. 2014) listed as new for the Mongolian floristic novelties and reported as well. This article includes the data on new species records for 33 species (2 subspecies and 1 varietes) included 20 genera and 14 families to the vascular flora of Mongolia. One genus (Matthiola) has been added as new to the flora of Mongolia. An annotated checklist of vascular plant species and phytogeography for Mongolia is given. The most made additions of the number of species of following families and genera: Ranunculaceae (12 species), Rosaceae (6 species), Brassicaceae (3 species) families and Potentilla (6 species), Ranunculus (4 species), and Aquilegia (3 species). The most made additions to the following phyto-geographical regions of Mongolia are: Mongolian Altai (11 species), Khentei (10 species) and Khangai (4 species) regions. The includes to new records for 10 species are as “sub-endemic“and one species as “very rare” to the vascular flora of Mongolia.
STEAM GASIFICATION OF SOME MONGOLIAN COALS
Authors: B Tungalagtamir , E Enkhtsetseg , Lumen Chao , M Narantsetseg , B Avid , B Ulziibat
Published: July 2017

The gasification tests for the Alagtolgoi and Ailbayan coal deposits were conducted in the temperature up to 850°C using bench scale reactor in order to evaluate product gas composition. Prior to the gasification experiments, the raw coal was pyrolysed in a stainless steel reactor under N2 atmosphere at a temperature of 500°C for 1 h. General behavior of the coal conversion was quite similar for both coals. The gasification tests show that an increase in temperature enhances the formation of hydrogen, carbon dioxide and carbon monoxide. The highest yield of hydrogen and carbon dioxide concentrations of the Ailbayan coal are achieved at temperature of 850°C, which were 2.859 mmol⋅g-1⋅min-1 and 1.054 mmol⋅g-1⋅min-1 respectively. However maximum rate of hydrogen for Alagtolgoi subbituminous coal reached around 800°C. Overall results show that the maximum gasification rate is reached earlier for subbituminous coal than for bituminous coal, but product gas evolution was higher for the investigated bituminous coal.
Measurement of snow cover depth using 100 × 100 meters sampling plot and Structure from Motion method in Adventdalen, Svalbard
Authors: Stuchlík Radim , Russnák Jan , Plojhar Tomáš , Stachoň Zdeněk
Published: July 2017

We tried to verify the concept of Structure from Motion method for measuring the volume of snow cover in a grid of 100×100 m located in Adventdalen, Central Svalbard. As referencing method we utilized 121 depth measurements in one hectare area. Using avalanche probe a snow depth was measured in mentioned 121 nodes of the grid. We detected maximum snow depth of 2.05 m but snowless parts as well. From gathered depths’ data we geostatistically (ordinary kriging) interpolated snow surface model which we used to determine reference volume of snow at research plot (5 569 m3). As a result, we were able to calculate important metrics and analyze topography and spatial distribution of snow cover at the plot. For taking photos for Structure from Motion method, bare pole in hands with a camera mounted was used. We constructed orthomosaic of research plot.
Structural and functional adaptations of epilithic lichens of Umbilicaria genus in the White Sea coastal conditions
Authors: Sonina Anzhella V. , A.Tsunskaya Anna
Published: July 2017

Anatomical and physiological characteristics (width of anatomical layers and the amount of photosynthetic pigments) of two epilithic lichen species Umbilicaria torrefacta (Lightf.) Schrader and U. deusta (L.) have been studied. The study took place on the supralittoral zone on the coast of the White Sea in two points: Kolezhma village and Keret village in 2014 and 2015. Ecological plasticity of mycobiont which contacts the environment and gives a niche to the photobiont have been revealed, based on the analysis of variance in the study of anatomical structures of two different types of habitats and between different samples of the same species. Coastal conditions provide favorable levels of humidity and light for the U. torrefacta and U. deusta species. This allows symbiotic organism to maintain a symbiotrophic balance due to the plasticity of the fungal symbiont which contacts the abiotic environment. At the same time these adaptation mechanisms do not include functional changes, such as photosynthetic apparatus of the autotrophic symbiont, conditions for which are set by the fungal organism. U. deusta and U. torrefacta species only show structural adaptations - the adaptations that follow the path of anatomical structure changes and the relative stability of the physiological parameters. The study shows that anatomical structure of thalli varies more significantly between the two species than within samples of the same species.
Intralandscape differentiation of the local flora in the central part of the Gydansky Peninsula (West Siberian Arctic)
Authors: Khitun Olga V.
Published: July 2017

The paper aims to describe Russian approaches to inventory of vascular plants diversity in the Russian Arctic. In the study, the local flora method is used. It provides comparable data for spatial comparisons between different locations. The method includes the study of species distributions within a landscape, therefore the concept of “partial flora” was elaborated. A complex estimate “activeness” allows to assess a species role within the landscape. These theoretical concepts are applied at the local flora of a hardly accessible central part of the Gydansky Peninsula. The local flora numbers 191 vascular plant species. Altogether, 18 habitat types were distinguished with partial floras numbering from 15 to 75 species. The highest alfa-diversity was recorded on steep slopes, many rare species occurred there as well. These habitats occupied less than 10% of the area but provided almost 75% of local flora. Although the morphology of relief was better developed at this locality compare to the others at the Gydansky Peninsula, the intralandscape structure of flora is continuous, showing a low beta-diversity and high similarity of species composition between different habitats. It is explained by a high proportion of “active” species, which occur in many different habitat types. Along the zonal gradient within the Gydansky Peninsula, a decrease of species richness at local flora level was found but no change at partial floras level.
Vieillissement de la génération X au Québec : vers un report de la retraite ?
Authors: Fleury Charles , Paré Pierre-Olivier
Published: July 2017

Cet article examine le bien-fondé des arguments voulant que les nouvelles générations québécoises travaillent moins que les générations précédentes et qu’elles soient plus enclines à prolonger leur vie professionnelle. Il s’appuie sur l’exploitation des données historiques de diverses enquêtes quantitatives réalisées depuis la fin des années 1970. Prenant le cas de la génération X pour témoin, il analyse, dans un premier temps, dans quelle mesure les membres de cette génération cumulent moins d’années d’activité professionnelle que les membres des générations précédentes au même âge et s’interroge sur les raisons de ce phénomène. Il se questionne ensuite sur la place qu’occupe le travail dans la vie quotidienne des membres de la génération X et discute des difficultés de conciliation travail-famille tout au long de la vie. Il s’interroge enfin sur les conséquences que les différents changements observés auront sur les aspirations des membres de la génération X à l’égard du travail et de la retraite.
Facteurs associés au recours à l’avortement à Lomé (Togo) : analyse d’une séquence d’étapes menant à l’avortement
Authors: N’Bouke Afiwa , Calvès Anne-Emmanuèle , Lardoux Solène
Published: July 2017

Cette étude examine les facteurs associés au recours à l’avortement à Lomé, la capitale et principale ville du Togo, en modélisant l’avortement comme une séquence d’étapes débutant par l’exposition au risque de grossesse jusqu’au recours à l’avortement, en passant par l’absence de pratique contraceptive et le fait qu’une grossesse qui survient soit déclarée comme étant « non désirée ». L’Enquête sur la planification familiale et l’avortement provoqué (EPAP) réalisée en 2002 auprès de 4 755 femmes âgées de 15-49 ans à Lomé fournit des caractéristiques au moment des grossesses et sert de base aux analyses. Les résultats révèlent que la religion, le statut matrimonial, l’âge, le niveau d’instruction et la parité sont associés aux quatre étapes de la séquence. Ainsi, plusieurs grossesses non désirées surviennent aux âges jeunes. Toutefois, c’est principalement le caractère « hors union » de la grossesse qui fait qu’elle est considérée comme étant « non désirée » et qu’elle est interrompue. Bien qu’étant moins à risque de grossesse, les femmes qui ont au moins deux enfants en vie sont plus susceptibles que les nullipares d’utiliser une contraception, moderne ou non, de déclarer une grossesse comme non désirée et d’avorter. À la lumière de ces résultats, une campagne de prévention efficace auprès des groupes à risque d’avorter devra également prendre en compte leur risque aux étapes antérieures à l’avortement.
Inference with Large Clustered Datasets
Authors: MacKinnon James G.
Published: July 2017

Inference using large datasets is not nearly as straightforward as conventional econometric theory suggests when the disturbances are clustered, even with very small intra-cluster correlations. The information contained in such a dataset grows much more slowly with the sample size than it would if the observations were independent. Moreover, inferences become increasingly unreliable as the dataset gets larger. These assertions are based on an extensive series of estimations undertaken using a large dataset taken from the U.S. Current Population Survey.
Efficacité et efficience statique et dynamique dans la régulation des télécommunications
Authors: MAKOSSO Béthuel
Published: July 2017

Cet article se propose de faire un réexamen des facteurs d’inefficacité de la régulation des télécommunications en mettant en avant le rôle de l’opportunisme qui lui est associé et les coûts de transaction qu’elle génère pour les firmes. En effet, bien que la présence d’organes de régulation dans cet environnement soit justifiée par le souci pour les pouvoirs publics de corriger les défaillances de tels marchés, l’évolution rapide de la technologie des télécommunications rend inadaptés les éléments caractéristiques de la régulation dans ce secteur (les objectifs, les outils et le processus décisionnel). Sujette à l’opportunisme et génératrice des coûts de transaction, la régulation des télécommunications, si elle permet d’assurer l’efficience statique au sens où la concurrence qu’elle favorise peut aider à réduire le pouvoir de marché des firmes, et donc à l’accroissement du surplus des consommateurs, elle est cependant loin d’intégrer les aspects inhérents à la dynamique propre du secteur des télécommunications, ceux qui conduiraient à l’efficience dynamique. D’où la nécessité de concevoir un système de régulation optimal intégrant les modèles dynamiques qui puissent concilier efficience statique et efficience dynamique.
Nowcasting commodity prices using social media
Authors: Kim Jaewoo , Cha Meeyoung , Lee Jong Gun
Published: July 2017

Gathering up-to-date information on food prices is critical in developing regions, as it allows policymakers and development practitioners to rely on accurate data on food security. This study explores the feasibility of utilizing social media as a new data source for predicting food security landscape in developing countries. Through a case study of Indonesia, we developed a nowcast model that monitors mentions of food prices on Twitter and forecasts daily price fluctuations of four major food commodities: beef, chicken, onion, and chilli. A longitudinal test over 15 months of data demonstrates that not only that the proposed model accurately predicts food prices, but it is also resilient to data scarcity. The high accuracy of the nowcast model is attributed to the observed trend that the volume of tweets mentioning food prices tends to increase on days when food prices change sharply. We discuss factors that affect the veracity of price quotations such as social network-wide sensitivity and user influence.
Use of multivariate control charts to assess the status of reef fish assemblages in the Northwestern Hawaiian Islands
Authors: Fukunaga Atsuko , Kosaki Randall K.
Published: July 2017

A distance-based multivariate control chart is a useful tool for ecological monitoring to detect changes in biological community resulting from natural or anthropogenic disturbances at permanent monitoring sites. It is based on a matrix of any distances or dissimilarities among observations obtained from species composition and abundance data, and bootstrapping techniques are used to set upper confidence bounds that trigger an alarm for further investigations. We extended the use of multivariate control charts to stratified random sampling and analyzed reef fish monitoring data collected annually on shallow (≤30 m) reefs across the Northwestern Hawaiian Islands (NWHI), part of the Papahānaumokuākea Marine National Monument. Fish assemblages in the NWHI were mostly stable, with exceptions in the south region (Nihoa, Mokumanamana and French Frigate Shoals) in 2012 and 2015 where changes in the assemblage structure exceeded the upper confidence bounds of multivariate control charts. However, these were due to changes in relative abundances of native species, and potentially related to the small numbers of survey sites and relatively low coral covers at the sites, particularly in 2015. The present study showed that multivariate control charts can be used to evaluate the status of biological communities in a very large protected area. Future monitoring of fish assemblages in the Papahānaumokuākea Marine National Monument should be accompanied by specific habitat or environmental variables that are related to potential threats to its shallow-water ecosystems. This should allow for more detailed investigations into potential causes and mechanisms of changes in fish assemblages when a multivariate control chart triggers an alarm.
Procalcitonin, C-Reactive Protein, and Fibrinogen Levels in Cases With Mechanic Bowel Obstruction and Their Changing in Relation With the Duration of Obstruction: An Experimental Study
Authors: Guzel Hakan , Kahramanca Sahin , Kaya Oskay , Ozgehan Gulay , Yilmazer Demet , Ucar Fatma , Bilgin Caglar
Published: July 2017

The need and timing of surgical intervention in patients with adhesive bowel obstruction is a dilemma. We aimed to investigate the role of 3 acute-phase reactants—namely, procalcitonin (PCT), fibrinogen, and C-reactive protein (CRP)—in this clinical condition. We chose a rat model whose mechanical bowel obstruction was created with cecum ligation. There were 2 study groups and 1 control group. Each group contained 10 subjects. The study groups had 3-hour and 6-hour obstruction samples. Blood PCT, fibrinogen, and CRP levels were measured before and after the surgical procedure. These parameters were compared between the groups, and they were also evaluated with the degree of histopathologic changes occurring in terminal ileal tissue samples. Compared with the control group, PCT measurements showed a mild decrease in the early phase of obstruction but a significant elevation in the late phase (P = 0.977 and P = 0.001). Unlike PCT, fibrinogen levels increased at first but decreased later (P = 0.978 and P = 0.326). We observed an increase in CRP levels parallel to the prolonged duration of obstruction (P = 0.987 and P = 0.134). With regard to mucosal injury, PCT levels increased at first, and then decreased (P = 0.003). On the other hand, fibrinogen and CRP levels decreased at first, and then increased (P = 0.139 and P = 0.102). The acute-phase reactants PCT, fibrinogen, and CRP, associated with the duration of obstruction, may help to determine the time of surgical intervention in patients with adhesive mechanical bowel obstruction.
A statistical survey of heat input parameters into the cusp thermosphere
Authors: Skjæveland Åsmund Steen , Carlson Herbert C. , Moen Jøran Idar
Published: July 2017

Based on three winters of observational data, we present those ionosphere parameters deemed most critical to realistic space weather ionosphere and thermosphere representation and prediction, in regions impacted by variability in the cusp. The CHAMP spacecraft revealed large variability in cusp thermosphere densities, measuring frequent satellite drag enhancements, up to doublings. The community recognizes a clear need for more realistic representation of plasma flows and electron densities near the cusp. Existing average value models produce order of magnitude errors in these parameters, resulting in large underestimations of predicted drag. We fill this knowledge gap with statistics‐based specification of these key parameters over their range of observed values. The European Incoherent Scatter Svalbard Radar tracks plasma flow Vi, electron density Ne, and electron, ion temperatures Te, Ti, with consecutive 2–3 min windshield wipe scans of 1000 × 500 km areas. This allows mapping the maximum Ti of a large area within or near the cusp with high temporal resolution. In magnetic field‐aligned mode the radar can measure high‐resolution profiles of these plasma parameters. By deriving statistics for Ne and Ti, we enable derivation of thermosphere heating deposition under background and frictional drag‐dominated magnetic reconnection conditions. We separate our Ne and Ti profiles into quiescent and enhanced states, which are not closely correlated due to the spatial structure of the reconnection foot point. Use of our data‐based parameter inputs can make order of magnitude corrections to input data driving thermosphere models, enabling removal of previous twofold drag errors.
Flash propagation and inferred charge structure relative to radar‐observed ice alignment signatures in a small Florida mesoscale convective system
Authors: Biggerstaff Michael I. , Zounes Zackery , Addison Alford A. , Carrie Gordon D. , Pilkey John T. , Uman Martin A. , Jordan Douglas M.
Published: July 2017

A series of vertical cross sections taken through a small mesoscale convective system observed over Florida by the dual‐polarimetric SMART radar were combined with VHF radiation source locations from a lightning mapping array (LMA) to examine the lightning channel propagation paths relative to the radar‐observed ice alignment signatures associated with regions of negative specific differential phase (KDP). Additionally, charge layers inferred from analysis of LMA sources were related to the ice alignment signature. It was found that intracloud flashes initiated near the upper zero‐KDP boundary surrounding the negative KDP region. The zero‐KDP boundary also delineated the propagation path of the lightning channel with the negative leaders following the upper boundary and positive leaders following the lower boundary. Very few LMA sources were found in the negative KDP region. We conclude that rapid dual‐polarimetric radar observations can diagnose strong electric fields and may help identify surrounding regions of charge.
Susceptibility of contrail ice crystal numbers to aircraft soot particle emissions
Authors: Kärcher B. , Voigt C.
Published: July 2017

We develop an idealized, physically based model describing combined effects of ice nucleation and sublimation on ice crystal number during persistent contrail formation. Our study represents the first effort to predict ice numbers at the point where contrails transition into contrail cirrus—several minutes past formation—by connecting them to aircraft soot particle emissions and atmospheric supersaturation with respect to ice. Results averaged over an observed exponential distribution of ice supersaturation (mean value 15%) indicate that large reductions in soot particle numbers are needed to lower contrail ice crystal numbers significantly for soot emission indices around 1015 (kg fuel)−1, because reductions in nucleated ice number are partially compensated by sublimation losses. Variations in soot particle (−50%) and water vapor (+10%) emission indices at threefold lower soot emissions resulting from biofuel blending cause ice crystal numbers to change by −35% and <5%, respectively. The efficiency of reduction depends on ice supersaturation and the size distribution of nucleated ice crystals in jet exhaust plumes and on atmospheric ice supersaturation, making the latter another key factor in contrail mitigation. We expect our study to have important repercussions for planning airborne measurements targeting contrail formation, designing parameterization schemes for use in large‐scale models, reducing uncertainties in predicting contrail cirrus, and mitigating the climate impact of aviation.
Multi‐TID detection and characterization in a dense Global Navigation Satellite System receiver network
Authors: Yang Heng , Monte‐Moreno Enrique , Hernández‐Pajares Manuel
Published: July 2017

The medium‐scale traveling ionospheric disturbances (MSTIDs) constitute the most frequent ionospheric wave signatures. We propose a method for detecting the number of simultaneous MSTIDs from a time series of high‐pass‐filtered Vertical Total Electron Content (VTEC) maps and their parameters. The method is tested on the VTEC map corresponding to a simulated realistic scenario and on actual data from dual‐frequency Global Positioning System (GPS) measurements gathered by +1200 GPS receivers of the GPS Earth Observation Network (GEONET) in Japan. The contribution consists of the detection of the number of independent MSTIDs from a nonuniform sampling of the ionospheric pierce points. The problem is set as a sparse decomposition on elements of a dictionary of atoms that span a linear space of possible MSTIDs. These atoms consist of plane waves characterized by a wavelength, direction, and phase on a surface defined, the part of the ionosphere sounded by the GEONET (i.e., 25°N to 50°N of latitude and 125°E to 155°E of longitude). The technique is related to the atomic decomposition and least absolute shrinkage and selection operator. The geophysical contribution of this paper is showing (a) the detection of several simultaneous MSTIDs of different characteristics, with a continuous change in the velocity; (b) detection of circular MSTID waves compatible by time and center with a specific earthquake; (c) simultaneous superposition of two distinct MSTIDs, with almost the same azimuth; and (d) the presence at nighttime of MSTIDs with velocities in the range 400–600 m/s.
Long‐term variations of exospheric temperature inferred from foF1 observations: A comparison to ISR Ti trend estimates
Authors: Perrone L. , Mikhailov A. V.
Published: July 2017

June noontime monthly median foF1 ionosonde observations at Sodankylä (auroral zone), Juliusruh, and Rome (middle latitudes) were used to retrieve exospheric temperature, Tex long‐term variations over the (1958–2015) period. After removing solar activity effects the residual linear trends were found to be small (0.05–0.6)% per decade and statistically insignificant at middle latitudes. Therefore, the revealed Tex long‐term variations are mainly due to long‐term variations of solar activity, i.e., they have a natural (not anthropogenic) origin. Large trends in ion temperature, Ti inferred from incoherent scatter radar (ISR) observations which the researchers identify with trends in neutral temperature, Tn may be related to the incoherent scatter method routinely based on a fixed model of ion composition (O+/Ne ratio and mean ion mass, correspondingly) under varying geophysical conditions. Mean ion mass number manifests a negative trend at 175 km which should correspond to a negative trend in Ti contrary the results obtained below 200 km with ISRs. Therefore, routine ISR observations based on a fixed model of ion composition may be not appropriate for long‐term trend analyses.
Application of a global magnetospheric‐ionospheric current model for dayside and terminator Pi2 pulsations
Authors: Imajo S. , Yoshikawa A. , Uozumi T. , Ohtani Shin. , Nakamizo A. , Chi P. J.
Published: July 2017

Pi2 magnetic oscillations on the dayside are considered to be produced by the ionospheric current that is driven by Pi2‐associated electric fields from the high‐latitude region, but this idea has not been quantitatively tested. The present study numerically tested the magnetospheric‐ionospheric current system for Pi2 consisting of field‐aligned currents (FACs) localized in the nightside auroral region, the perpendicular magnetospheric current flowing in the azimuthal direction, and horizontal ionospheric currents driven by the FACs. We calculated the spatial distribution of the ground magnetic field produced by these currents using the Biot‐Savart law in a stationary state. The calculated magnetic field reproduced the observational features reported by previous studies: (1) the sense of the H component does not change a wide range of local time sectors at low latitudes, (2) the amplitude of the H component on the dayside is enhanced at the equator, (3) the D component reverses its phase near the dawn and dusk terminators, (4) the meridian of the D component phase reversal near the dusk terminator is shifted more sunward than that near the dawn terminator, and (5) the amplitude of the D component in the morning is larger than that in the early evening. We also derived the global distributions of observed equivalent currents for two Pi2 events. The spatial patterns of dayside equivalent currents were similar to the spatial pattern of numerically derived equivalent currents. The results indicate that the oscillation of the magnetospheric‐ionospheric current system is a plausible explanation of Pi2s on the dayside and near the terminator.
Effect of pore and confining pressure on the supercritical CO2 permeability of sandstone: Implications for the effective pressure law
Authors: Choi C. S. , Cheon D. S. , Song J. J.
Published: July 2017

The liquid permeability of rock with distilled water or brine is different from that obtained using gas by variation in the confining pressure Pc and pore pressure Pp. In this study, as part of the research on CO2 geological storage, the permeability of sandstone was measured using supercritical CO2, and the effect of Pc and Pp on this permeability was analyzed. For applying the effective pressure law to the analysis, an effective pressure coefficient for permeability was derived experimentally. In order to utilize supercritical CO2, a non‐Darcy flow test with a high flow rate was conducted, and the permeability was estimated through the Forchheimer equation. We contoured iso‐permeability lines with confining and pore pressure conditions that have identical permeability, and the effective pressure coefficient, χ, was derived from the gradient of the lines following the definition of the effective pressure law. It was identified that the coefficient could be different depending on the pressure conditions. To clarify the variation of the coefficient, we derived the coefficient of χ(Pc, Pp) as a function of pore and confining pressure. The coefficient increased nonlinearly as the difference between Pc and Pp decreased, with a maximum of 1.36 being observed. The correlation between the effective pressure and the permeability were examined by applying empirical models. It was determined that the power law model was appropriate to estimate the change in supercritical CO2 permeability. Especially, it was deduced that the effective pressure with the derived coefficient would be more valid than the Terzaghi effective pressure.