bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Throughput in SCTP via Dynamic Optimization of Retransmission Bounds
Authors: McClellan Stan , Peng Wuxu , Gonzalez Ed
Published: December 2015

The Stream Control Transmission Proto-col (SCTP) is a relatively new transport protocol. Ithas several underlying mechanisms that are similar tothe Transmission Control Protocol (TCP), as well asseveral improvements that are important in certainclasses of applications. The timeout scheme of SCTP,however, is almost identical to that used in TCP.With the dynamics of today’s Internet, that timeoutscheme may be too passive. This paper presents an al-gorithm which dynamically adjusts the overall contextof the retransmission timeout process without chang-ing the fundamental retransmission mechanisms. Thisapproach manages the impact of fast retransmissionsand timeouts to significantly improve the throughputof SCTP applications. The algorithm has been im-plemented and tested in real network environments.Experimental results show that the algorithm avoidsspurious retransmissions and provides better through-put by intelligently managing RTO boundaries andallowing conventional timeout schemes to participatemore actively in the retransmission process.
Students’ Preferences on the Use of Mother Tongue in English as a Foreign Language Classrooms: Is it the Time to Re-examine English-only Policies?
Authors: Debreli Emre , Oyman Nadire
Published: December 2015

In literature on bilingual teaching, different perspecttives exist for and against the use of first language (L1) in English as a Foreign Language (EFL) classrooms. There is a continuing matter of debate on whether L1 contributes to or precludes the learning of a second language (L2). Numerous studies have been conducted on this topic, but no clear consensus exists on whether L1 should be banned or its inclusion in EFL classrooms should be allowed. A significant body of literature has explored this phenomenon from teachers’ perspectives, and an adequate number of studies have explored the phenomenon from the students’ perspectives. However, few studies have identified the reasons for which students need such an inclusion. More importantly, no studies seem to have considered demographic variables that may directly influence students’ perceptions of the use of L1 in their (L2) classrooms, that is; educational background and their language proficiency level. This study primarily investigated whether students’ educational background and their L2 proficiency influenced their perceptions of the use of Turkish in their L2 classrooms as well as their perceptions and needs for the use of L1 in their classrooms. The study was conducted on a sample of 303 Turkish learners of EFL at English Preparatory School of European University of Lefke in Northern Cyprus. Data were collected using a questionnaire. Analysis of the data indicated that EFL students had high positive perceptions toward the inclusion of L1 in their L2 classes and that their perceptions were affected by their demographic characteristics. Students with lower level of L2 proficiency were also found to have more positive perceptions toward the use of L1. Furthermore, the particular issues where students needed L1 were also identified. Implications for language teachers and policy makers are discussed.
Methodical Approaches to the Study of Human Chromosomal Q-Heterochromatin Variability
Authors: Ibraimov A. I.
Published: December 2015

In spite of the fact that chromosomal Q-heterochromatin regions (Q-HRs) in the genome have been opened almost half a century ago, we still know extremely few of their possible roles in the human life activity. One of the reasons of such state is the lack of methodical approaches mostly suitable to the nature and features for chromosomal Q-HRs. In the present work the existing methodical approaches of the human chromosomal Q-HRs has been analyzed, beginning from empirical observations up to the analytical approaches, aimed to detect regularities of Q-HRs distribution and possible effects at population level, in norm and pathology. It is appeared, that all depends on how we consider the nature of chromosomal Q-HRs, namely, whether they are structurally uniform formations in genome or their possible effects depend on features of Q-HRs localization on this or that chromosome in the human karyotype.
Mesenchymal Stem Cells and Cardiomyocytes Interplay to Prevent Myocardial Hypertrophy
Authors: Cai Benzhi , Tan Xueying , Zhang Yong , Li Xingda , Wang Xinyue , Zhu Jiuxin , Wang Yang , Yang Fan , Wang Baoqiu , Liu Yanju , Xu Chaoqian , Pan Zhenwei , Wang Ning , Yang Baofeng , Lu Yanjie
Published: December 2015

Bone marrow-derived mesenchymal stem cells (BMSCs) have emerged as a promising therapeutic strategy for cardiovascular disease. However, there is no evidence so far that BMSCs can heal pathological myocardial hypertrophy. In this study, BMSCs were indirectly cocultured with neonatal rat ventricular cardiomyocytes (NRVCs) in vitro or intramyocardially transplanted into hypertrophic hearts in vivo. The results showed that isoproterenol (ISO)-induced typical hypertrophic characteristics of cardiomyocytes were prevented by BMSCs in the coculture model in vitro and after BMSC transplantation in vivo. Furthermore, activation of the Ca2+/calcineurin/nuclear factor of activated T cells cytoplasmic 3 (NFATc3) hypertrophic pathway in NRVCs was abrogated in the presence of BMSCs both in vitro and in vivo. Interestingly, inhibition of vascular endothelial growth factor (VEGF) release from BMSCs, but not basic fibroblast growth factor and insulin-like growth factor 1, abolished the protective effects of BMSCs on cardiomyocyte hypertrophy. Consistently, VEGF administration attenuated ISO-induced enlargement of cellular size; the upregulation of atrial natriuretic peptide, brain natriuretic peptide, and β-myosin heavy chain expression; and the activation of Ca2+/calcineurin/NFATc3 hypertrophic pathways, and these pathways can be abrogated by blocking VEGFR-1 in cardiomyocytes, indicating that VEGF receptor 1 is involved in the antihypertrophic role of VEGF. We further found that the ample VEGF secretion contributing to the antihypertrophic effects of BMSCs originates from the crosstalk of BMSCs and cardiac cells but not BMSCs or cardiomyocytes alone. Interplay of mesenchymal stem cells with cardiomyocytes produced synergistic effects on VEGF release. In summary, crosstalk between mesenchymal stem cells and cardiomyocytes contributes to the inhibition of myocardial hypertrophy via inhibiting Ca2+/calcineurin/NFATc3 hypertrophic pathways in cardiac cells. These results provide the first evidence for the treatment of myocardial hypertrophy using BMSCs.

Significance

This study found that mesenchymal stem cells may crosstalk with cardiomyocytes, which causes a synergistic vascular endothelial growth factor (VEGF) release from both kinds of cells and then inhibits pathological cardiac remodeling following hypertrophic stimulation in cardiomyocytes in vitro and in vivo. Blockage of VEGF release from bone marrow-derived mesenchymal stem cells (BMSCs) abolishes the antihypertrophic actions of BMSCs in vitro and in vivo. On the contrary, VEGF administration attenuates hypertrophic signaling of calcineurin/ nuclear factor of activated T cell cytoplasmic 3 signal pathways. This study provides the first evidence for the treatment of myocardial hypertrophy using BMSCs.
Economic Growth and Financial Instability: The Ideas of Hayek and Keynes
Authors: Orlik Noemi Levy
Published: December 2015

Complex monetary systems in capitalist economies, whose financial markets can cause financial instabilities and economic downturns is an accepted argument by both John M. Keynes and Friedrich A. Hayek, disagreeing in terms of the factors generating financial instability, the mechanism in which financial variables affect the real sector, and more importantly how to generate economic growth.In this paper we discuss Hayek and the Austrian monetary school innovative ideas in terms of money in capitalist economies (i.e., liquidity provisions and credit devaluations) from where the monetarism and later the New Classical framework developed; and revise Keynes and Post Keynesian views that recognized the full effects of money in productions arguing that debts precede money, which is non neutral, thereby can expand economic activity but also unfold financial instability.We concentrate in the dissenting views over financial instability and argue that the main way to overcome economic activity is through expansive fiscal policies, opposing wages cuts, along financial market regulation.
Contenidos y procesos en pedagogía social: deconstrucción de la última etapa de producción
Authors: Rabadán Rubio José Antonio , Hernández Pérez Encarnación
Published: December 2015

A la hora de abordar los contenidos y procesos de la Pedagogía Social es claro indicar que no estamos ante un asunto baladí ni sencillo, ya que es un saber en permanente construcción. En la mayoría de los casos, la praxis va muy por delante de la reflexión teórica e incluso, la acción, debería tener un peso más relevante que la propia teoría. A pesar de las dificultades planteadas, nuestro objetivo en este artículo es el de analizar la producción científica realizada por los profesionales orientados al ámbito de la Pedagogía Social
en nuestro país, por medio de sus órganos de expresión más relevantes, Revista Interuniversitaria de Pedagogía Social y Seminario Interuniversitario de Pedagogía Social. Para ello, revisaremos investigaciones, contenidos y procesos de la disciplina planteando así un breve  recorrido de la última etapa en la producción científica de esta disciplina. Con ello, pretendemos proporcionar un conocimiento objetivo y científico sobre el desarrollo de esta ciencia pedagógica, su realidad actual y sus nuevos retos ante las dinámicas sociales imperantes.
Música, movimiento y danza: un enfoque integrador para la formación inicial del profesorado
Authors: Sánchez Ariño Silvia , Cañabate Ortiz Dolors , Calbó Angrill Montserrat , Viscarro Tomás Isabel
Published: December 2015

La consideración del cuerpo y del movimiento como medios de expresión y comprensión musical tendría que formar parte de una educación musical activa y vivencial. El estudio que se ha llevado a término describe cómo se integra y desarrolla el trabajo del movimiento y la danza en las sesiones de educación musical de 19 escuelas a partir de las observaciones e intervenciones de estudiantes de Magisterio Musical en prácticas. Las conclusiones del estudio apuntan a que, si bien hay una cierta integración del movimiento y la danza en la educación musical, es necesario mejorar aspectos como el del trabajo de la improvisación y la composición corporal, ambos instrumentos imprescindibles para el  desarrollo de las capacidades creativas y comunicativas del alumnado.
Hermenéutica de la educación y nuevas fronteras entre las diferencias
Authors: González Pérez Teresa , Gramigna Anita
Published: December 2015

Pretendemos trazar a lo largo de este trabajo las líneas de la epistemología del pensamiento narrativo, una vez aclarado que el pensamiento científico se sirve de representaciones unidas por las narraciones. Nuestro intento surge de la exigencia por clarificar qué es lo que está implícito, cuáles las premisas de nuestra mirada, de nuestra investigación, porque el resultado de nuestro proceder tiene mucho que ver con aquello que está implícito, con las premisas. Estudiar las representaciones de la técnica y de la ciencia nos pueden ayudar a comprender la estructura de los razonamientos y procedimientos que han llevado a grandes descubrimientos y que también han abierto nuestro futuro a riesgos inquietantes, sobre todo cuando parece minar el equilibrio que rige las relaciones dinámicas de la vida sobre el planeta. La experiencia humana y, por tanto, las prácticas relacionadas con la formación,  revisten un carácter esencialmente interpretativo que nos incita, en la investigación pedagógica, como en la práctica educativa, a un esfuerzo de comprensión, antes que a la explicación de los fenómenos. Partimos de una hermenéutica deconstructiva que vence tanto el determinismo de las reconstrucciones a posteriori, como el nihilismo de la secularización. Pensamos en una narración que interpreta al otro como parte de sí mismo, semilla fecunda de una relacionalidad que representa el principio ontológico de la hermenéutica educativa. El proceso constructivo de los pensamientos, sentimientos,
acciones, símbolos, estética, juicios morales, junto con otros, nos involucran y nos transforman en la aventura del conocimiento. El concepto de diferencia se asume como fundamentación educativa. Sin embargo, sin diferencia no puede existir la relación y, en consecuencia, tampoco la educación.
L’ambivalence de la transmission des normes du genre par les mères lesbiennes : de la critique des stéréotypes à leur reproduction « pour le bien de l’enfant »
Authors: Frémont Camille
Published: December 2015

Ce travail s’appuie sur des récits de mères lesbiennes recueillis dans le cadre d’un travail de recherche en sociologie, mené en France, sur la transmission du genre dans les familles lesboparentales. Ce travail visait à répondre à la question suivante : quelles représentations ont les mères lesbiennes ont-elles des normes du genre et de la socialisation de genre de leurs enfants ?

D’un point de vue individuel, les enquêtées démontrent une réelle remise en question des normes du genre. Elles manifestent un détachement de la pensée hétéronormative par une critique des stéréotypes de genre, une dénonciation du sexisme et une certaine « déshétérosexualisation » dans la manière de parler de soi et dans leur apparence. Le fonctionnement des couples au quotidien montre une plus grande égalité que dans le modèle hétérosexuel traditionnel de l’organisation domestique et des rôles parentaux.

Elles développent des discours présentant leur mode de vie sous un jour positif et dans lesquels elles affirment de manière argumentée la non-nécessité de la différence des sexes au niveau du couple parental. Ces arguments se retrouvent dans les récits de conception qu’elles construisent pour leurs enfants, afin que ceux-ci se structurent à partir d’une vision valorisante de leur famille. Les récits de conception proposent une définition de la famille dans laquelle procréation et conjugalité sont dissociées. En revanche, leur sentiment de légitimité semble rester vulnérable face à l’homophobie latente, non explicitement hostile, dont elles citent, en les minimisant, les nombreuses conséquences au quotidien.

Aussi, bien que prédisposées à transmettre des modèles d’identification éloignés des stéréotypes de genre, les mères lesbiennes interrogées sont attentives à promouvoir auprès de leurs enfants les signes d’une socialisation de genre normative, afin de les protéger de la désapprobation sociale à laquelle elles ont le sentiment de les exposer par leur modèle familial atypique. Elles leur apprennent à maîtriser les arguments qui leur permettront de se présenter de manière lisible et acceptable socialement.
Analyse du fonctionnement psychique d’enfants grandissant avec un couple de femmes
Authors: Moget Émilie , Heenen-Wolff Susann
Published: December 2015

De nombreuses recherches ont été menées ces 35 dernières années auprès des familles homoparentales. Majoritairement de type quantitatif, ces études nous informent peu sur le fonctionnement dynamique et singulier de ces familles. Au travers d’une étude exploratoire et longitudinale, nous analysons le vécu particulier de familles homoparentales (deux femmes) qui ont eu recours à la procréation assistée avec don de sperme anonyme. Nous explorons dans notre recherche les sujets suivants : le rôle des mères auprès de l’enfant, la place du donneur anonyme dans le roman familial, le rapport de l’enfant à ses origines, le développement de l’identité sexuelle de l’enfant, l’intégration de ces familles dans une société hétéronormative. Grâce à nos rencontres régulières avec les enfants et les parents nous pouvons mettre en lumière les spécificités de leur fonctionnement familial. L’originalité de notre recherche se situe dans l’exploration du vécu intrapsychique et intersubjectif de ces enfants. Nous tentons de comprendre comment les enfants dont les parents sont de même sexe se construisent psychiquement. L’utilisation d’outils projectifs thématiques (Patte Noire, CAT, Dessin de famille) nous fournit des informations précieuses quant à leur développement psychosexuel. Ce matériel est à la source d’une double sollicitation, à la fois perceptive et projective, ce qui nous permet de relever des indices sur la manière dont l’enfant perçoit ses relations, se les représente et les symbolise. La description de cas cliniques illustrera nos propos.
Transparentalité : vécus sensibles de parents et d’enfants (France, Québec)
Authors: Fortier Corinne
Published: December 2015

La transparentalité représente une épreuve sociale et intime autant pour les personnes concernées que pour leurs conjoints et leurs enfants. Il existe peu de recherches sur ce sujet sensible, et encore moins de témoignages d’enfants. Dans cette étude qui croise anthropologie et psychologie, j’ai voulu rendre compte de la manière la plus juste de la parole des personnes rencontrées, en faisant état de leurs sentiments, de leur parcours, de leurs difficultés, de leurs doutes et de leurs victoires, sans jugement de valeur. Dans le cadre limité de cet article, je présente le cas de femmes trans, soit des personnes nées hommes et devenues femmes, qui étaient déjà mariées ou en couple avec une compagne avant leur transition et qui ont eu des enfants dans le cadre de cette union. Leurs récits de vie attestent de leur manière d’ajuster leur transition en femme à leur rôle parental, même si elles doivent faire face à beaucoup d’incompréhension, sinon d’exclusion. J’examine aussi comment les enfants réagissent au changement d’identité sexuée de leur parent, réaction qui peut évoluer au cours du temps, et qui est intrinsèquement liée à la façon dont la nouvelle leur est annoncée, à leur âge, à l’attitude de leur mère et de leur famille proche, ainsi qu’au regard social porté sur la transparentalité.
High-level simulation of concurrency operations in microthreaded many-core architectures
Authors: Uddin Irfan
Published: December 2015

Computer architects are always interested in analyzing the complex interactions amongst the dynamically allocated resources. Generally a detailed simulator with a cycle-accurate simulation of the execution time is used. However, the cycleaccurate simulator can execute at the rate of 100K instructions per second, divided over the number of simulated cores. This means that the evaluation of a complex application with complex concurrency interactions on contemporary multi-core machine can be very slow. To perform efficient design space exploration we present a co-simulation environment, where the detailed execution of concurrency instructions in the pipeline of microthreaded cores and the interactions amongst the hardware components are abstracted. We present the evaluation of the high-level simulation framework against the cycle-accurate simulation framework. The results show that high-level simulator is faster and less complicated than cycle-accurate simulator and has reasonable accuracy.
An evaluation of community pharmacy-based services for type 2 diabetes in an Indonesian setting: patient survey
Authors: Wibowo Yosi , Parsons Richard , Sunderland Bruce , Hughes Jeffery
Published: December 2015

Background.Diabetes is an emerging chronic disease in developing countries. Its management in developing countries is mainly hospital/clinic based. The increasing diabetes burden in developing countries provides opportunities for community pharmacists to deliver a range of services. Since the management of diabetes requires the patient’s own involvement, it is important to gain their views in order to develop pharmacy-based diabetes services. Studies on diabetes patients’ views have been limited to developed countries.

Objectives.To investigate, within a developing country setting (Indonesia), current use of pharmacy services by type 2 diabetes patients, and to evaluate their views regarding community pharmacists’ roles, and the characteristics that influence their views.

Methods.A questionnaire survey was conducted within 10 purposefully selected community pharmacies in Surabaya, Indonesia. Each pharmacy recruited approximately 20 patients seeking antidiabetic medications. Usage of pharmacy services was identified using binary responses (‘yes’/‘no’) and views on pharmacists’ roles were rated using Likert scales; an open-ended question was used to identify patient perceived priority roles. Logistic regression models were used to determine characteristics associated with patients’ views.

Results.A total of 196 pharmacy patients with type 2 diabetes responded (58.3% response rate). Most patients used community pharmacies for dispensing (100%) and education on how to use medications (79.6%). There were mixed views towards pharmacists providing services beyond dispensing. The highest priorities identified were from the ‘patient education’ domain: education on medications (i.e., directions for use (64.5%), storage (26.6%), common/important adverse effects (25.5%)); and the ‘monitoring’ domain: monitoring medication compliance (37.3%). Patients with higher incomes or who were working were less supportive of these expanded services, whereas patients who previously used a service, those with risk factors for complications or having poor/unknown glycaemic control were more supportive.

Conclusions.Community pharmacies in Surabaya, Indonesia in this study were mainly utilised for dispensing. However, many type 2 diabetes patients using these pharmacies report limited monitoring of blood glucose levels and poor glycaemic control, which indicates an opportunity for greater pharmacist involvement. Yet for this to occur, patients’ limited expectations of pharmacists roles will need to be broadened. Characteristics influencing these views should inform the development of pharmacy-based diabetes services in the environment of the burgeoning burden of diabetes.
Flood induced phenotypic plasticity in amphibious genusElatine(Elatinaceae)
Authors: Molnár V. Attila , Tóth János Pál , Sramkó Gábor , Horváth Orsolya , Popiela Agnieszka , Mesterházy Attila , Lukács Balázs András
Published: December 2015

Vegetative characters are widely used in the taxonomy of the amphibious genusElatineL. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nineElatinespecies (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda,E. orthospermaandE. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors.
Low oxygen alters mitochondrial function and response to oxidative stress in human neural progenitor cells
Authors: Lages Yury M. , Nascimento Juliana M. , Lemos Gabriela A. , Galina Antonio , Castilho Leda R. , Rehen Stevens K.
Published: December 2015

Oxygen concentration should be carefully regulated in all living tissues, beginning at the early embryonic stages. Unbalances in oxygen regulation can lead to cell death and disease. However, to date, few studies have investigated the consequences of variations in oxygen levels for fetal-like cells. Therefore, in the present work, human neural progenitor cells (NPCs) derived from pluripotent stem cells grown in 3% oxygen (v/v) were compared with NPCs cultured in 21% (v/v) oxygen. Low oxygen concentrations altered the mitochondrial content and oxidative functions of the cells, which led to improved ATP production, while reducing generation of reactive oxygen species (ROS). NPCs cultured in both conditions showed no differences in proliferation and glucose metabolism. Furthermore, antioxidant enzymatic activity was not altered in NPCs cultured in 3% oxygen under normal conditions, however, when exposed to external agents known to induce oxidative stress, greater susceptibility to DNA damage was observed. Our findings indicate that the management of oxygen levels should be considered forin vitromodels of neuronal development and drug screening.
On the embryonic cell division beyond the contractile ring mechanism: experimental and computational investigation of effects of vitelline confinement, temperature and egg size
Authors: Gladilin Evgeny , Eils Roland , Peshkin Leonid
Published: December 2015

Embryonic cell division is a mechanical process which is predominantly driven by contraction of the cleavage furrow and response of the remaining cellular matter. While most previous studies focused on contractile ring mechanisms of cytokinesis, effects of environmental factors such as pericellular vitelline membrane and temperature on the mechanics of dividing cells were rarely studied. Here, we apply a model-based analysis to the time-lapse imaging data of two species (Saccoglossus kowalevskiiandXenopus laevis) with relatively large eggs, with the goal of revealing the effects of temperature and vitelline envelope on the mechanics of the first embryonic cell division. We constructed a numerical model of cytokinesis to estimate the effects of vitelline confinement on cellular deformation and to predict deformation of cellular contours. We used the deviations of our computational predictions from experimentally observed cell elongation to adjust variable parameters of the contractile ring model and to quantify the contribution of other factors (constitutive cell properties, spindle polarization) that may influence the mechanics and shape of dividing cells. We find that temperature affects the size and rate of dilatation of the vitelline membrane surrounding fertilized eggs and show that in native (not artificially devitellinized) egg cells the effects of temperature and vitelline envelope on mechanics of cell division are tightly interlinked. In particular, our results support the view that vitelline membrane fulfills an important role of micromechanical environment around the early embryo the absence or improper function of which under moderately elevated temperature impairs normal development. Furthermore, our findings suggest the existence of scale-dependent mechanisms that contribute to cytokinesis in species with different egg size, and challenge the view of mechanics of embryonic cell division as a scale-independent phenomenon.
Efficiently detecting outlying behavior in video-game players
Authors: Kim Young Bin , Kang Shin Jin , Lee Sang Hyeok , Jung Jang Young , Kam Hyeong Ryeol , Lee Jung , Kim Young Sun , Lee Joonsoo , Kim Chang Hun
Published: December 2015

In this paper, we propose a method for automatically detecting the times during which game players exhibit specific behavior, such as when players commonly show excitement, concentration, immersion, and surprise. The proposed method detects such outlying behavior based on the game players’ characteristics. These characteristics are captured non-invasively in a general game environment. In this paper, cameras were used to analyze observed data such as facial expressions and player movements. Moreover, multimodal data from the game players (i.e., data regarding adjustments to the volume and the use of the keyboard and mouse) was used to analyze high-dimensional game-player data. A support vector machine was used to efficiently detect outlying behaviors. We verified the effectiveness of the proposed method using games from several genres. The recall rate of the outlying behavior pre-identified by industry experts was approximately 70%. The proposed method can also be used for feedback analysis of various interactive content provided in PC environments.
Establishing the role of honest broker: bridging the gap between protecting personal health data and clinical research efficiency
Authors: Choi Hyo Joung , Lee Min Joung , Choi Chang-Min , Lee JaeHo , Shin Soo-Yong , Lyu Yungman , Park Yu Rang , Yoo Soyoung
Published: December 2015

Background.The objective of this study is to propose the four conditions for the roles of honest brokers through a review of literature published by ten institutions that are successfully utilizing honest brokers. Furthermore, the study aims to examine whether the Asan Medical Center’s (AMC) honest brokers satisfy the four conditions, and examine the need to enhance their roles.

Methods.We analyzed the roles, tasks, and types of honest brokers at 10 organizations by reviewing the literature. We also established a Task Force (TF) in our institution for setting the roles and processes of the honest broker system and the honest brokers. The findings of the literature search were compared with the existing systems at AMC—which introduced the honest broker system for the first time in Korea.

Results.Only one organization employed an honest broker for validating anonymized clinical data and monitoring the anonymity verifications of the honest broker system. Six organizations complied with HIPAA privacy regulations, while four organizations did not disclose compliance. By comparing functions with those of the AMC, the following four main characteristics of honest brokers were determined: (1) de-identification of clinical data; (2) independence; (3) checking that the data are used only for purposes approved by the IRB; and (4) provision of de-identified data to researchers. These roles were then compared with those of honest brokers at the AMC.

Discussion.First, guidelines that regulate the definitions, purposes, roles, and requirements for honest brokers are needed, since there are no currently existing regulations. Second, Korean clinical research institutions and national regulatory departments need to reach a consensus on a Korean version of Limited Data Sets (LDS), since there are no lists that describe the use of personal identification information. Lastly, satisfaction surveys on honest brokers by researchers are necessary to improve the quality of honest brokers.
Assessing the ability of Pleiades stereo imagery to determine height changes in earthquakes: A case study for the El Mayor‐Cucapah epicentral area
Authors: Zhou Yu , Parsons Barry , Elliott John R , Barisin Ivana , Walker Richard T
Published: December 2015

High‐resolution surface topography is valuable for studying coseismic fault zone deformation and fault geometry. It enables us to measure three‐dimensional surface displacements in earthquakes, as shown in recent studies that used light detection and ranging (lidar) to determine coseismic motion. However, the applicability of lidar is limited by its relatively high cost and low availability. In this study, we use the 2010 El Mayor‐Cucapah earthquake to demonstrate the capability of Pleiades stereo imagery to measure coseismic vertical ground displacement. We acquired post‐earthquake Pleiades tristereo imagery from backward, near‐nadir, and forward orientations for a 45 km × 7 km portion of the epicentral area. One meter resolution digital elevation models (DEMs) were produced with the four different combinations of incidence angles and compared to the post‐earthquake lidar DEM. Elevations from tristereo have slightly (∼15%) smaller uncertainties than bistereo as the tristereo DEM incorporates more observations. Elevation differences between the Pleiades and post‐earthquake lidar DEMs show that the vertical accuracy of the Pleiades DEMs is ∼0.3 m. By differencing the Pleiades DEM and the pre‐earthquake, 5 m resolution lidar DEM, we mapped meter and submeter offsets along the faults obtaining results comparable to a previous study that differenced the two lidar DEMs. This is the first case study of assessing very high resolution (VHR) satellite stereo imagery to determine submeter vertical ground displacement in an earthquake. By extension, we expect it to be possible to measure submeter vertical offsets occurring in earthquakes using pre‐earthquake and post‐earthquake VHR stereo imagery.
Rain effects on the hurricane observations over the ocean by C‐band Synthetic Aperture Radar
Authors: Zhang Guosheng , Li Xiaofeng , Perrie William , Zhang Biao , Wang Lei
Published: December 2015

A composite radar scattering model composed of the atmosphere radiative transfer model, and the ocean surface Bragg wave theory is developed to analyze the impact of hurricane rain on the normalized radar‐backscatter cross section (NRCS) measured in the VV and cross‐polarized C‐band Synthetic Aperture Radar (SAR) channels. The model results are validated against SAR and SFMR measured wind speeds and rain rates for two hurricane cases. The contribution of rain to the NRCS is backscatter from two parts: the atmosphere column and the ocean surface. In the atmosphere, microwave attenuation and the rain‐induced volume backscattering are simulated by the model. We find that the impact of raindrops in the atmosphere is almost negligible for the VV polarization, but important for the cross polarization. On the ocean surface, comparisons between our model and other existing models without rain lead to the conclusion that the VV polarization NRCS can be simulated reasonably well without considering the non‐Bragg scattering mechanisms. Similar to the wave breaking mechanism, the microwave diffraction on the craters, crowns, and stalks, produced by rain drops, is also negligible for VV polarization. However, the non‐Bragg scattering is important for the cross‐polarized NRCS simulations. Finally, we performed simulations to understand the VV‐polarized NRCS behavior under different wind speeds at various rain rates.
Wave dynamics of a Pacific Atoll with high frictional effects
Authors: Rogers Justin S. , Monismith Stephen G. , Koweek David A. , Dunbar Robert B.
Published: December 2015

We report field measurements of waves and currents made from September 2011 to July 2014 on Palmyra Atoll in the central Pacific that were used in conjunction with the SWAN wave model to characterize the wave dynamics operant on the atoll. Our results indicate that wave energy is primarily from the north during the northern hemisphere winter and from the south in the northern hemisphere summer. Refraction of waves along the reef terraces due to variations in bathymetry leads to focusing of waves in specific locations. Bottom friction, modeled with a modified bottom roughness formulation, is the significant source of wave energy dissipation on the atoll, a result that is consistent with available observations of wave damping on Palmyra. Indeed modeled wave dissipation rates from bottom friction are on average larger than dissipation rates due to breaking and are an order of magnitude larger than what has been observed on other, less geometrically complex reefs, a result which should be corroborated with future in situ measurements. The SWAN wave model with a modified bottom friction formulation better predicts bulk wave energy properties than the existing formulation at our measurement stations. The near bed squared velocity, a proxy for bottom stress, shows strong spatial variability across the atoll and exerts control over geomorphic structure and benthic community composition.
Parameterization of intrawave ripple‐averaged sediment pickup above steep ripples
Authors: Amoudry L. O. , Souza A. J. , Thorne P. D. , Liu P. L.‐F.
Published: December 2015

Near‐bed sediment pickup is critical for predictions of intrawave suspension and in turn net sediment transport in coastal models. In the present study, numerical results from a two‐dimensional Reynolds‐averaged Navier‐Stokes model are used to assess the functional relationship of intrawave ripple‐averaged sediment pickup above steep ripples. The numerical model provides intrawave time histories of ripple‐averaged near‐bed velocities and turbulence, which are qualitatively interrogated to determine pickup functional relationships. Several specific sediment pickup formulations are implemented within the numerical model: expressions relating pickup to near‐bed velocity or near‐bed turbulent kinetic energy via the bed shear stress; and expressions relating pickup to near‐bed shear production of turbulent kinetic energy. These are then tested via model‐data comparisons of near‐bed suspended sediment concentration. The results show that the traditional functions relating sediment pickup to near‐bed velocity cannot lead to reasonable intrawave suspension predictions above vortex ripples under a ripple‐averaged framework. Instead, relating sediment pickup to near‐bed turbulence quantities, such as turbulent kinetic energy or shear production of turbulent kinetic energy, significantly improves the numerical predictions for these conditions.
Mobile mud dynamics in the East China Sea elucidated using 210Pb, 137Cs, 7Be, and 234Th as tracers
Authors: Wang Jinlong , Du Jinzhou , Baskaran Mark , Zhang Jing
Published: December 2015

“Mobile mud” (MM), which has fine grain size distribution (>90% clay + silt, and <5% sand) and high porosity (≥0.50), plays an important role in the biogeochemical cycles in the estuarine areas and the inshore shelf. A suite of MM samples from the coastal area of the East China Sea (ECS) was collected in spring and summer of 2011 to observe their spatial and temporal distribution, grain size, and radionuclides concentrations. The MM thickness ranged from 0.5 to 11 cm (average: 2.2 cm (May) and 3.9 cm (August)). The thick mud layer is mainly distributed along the coast, with an area of 2.2 × 104 km2 in May and 1.5 × 104 km2 in August, with corresponding masses of 8.8 × 108 and 7.8 × 108 t, respectively. The estimated masses of MM are considerably larger than the annual sediment discharge mass of the Changjiang River. The distribution of 137Cs inventories in MM indicates that 137Cs can be effectively utilized as a transport tracer of MM in the river‐dominated estuaries and coastal areas. The higher inventories of 7Be in MM in the river mouth in spring are attributed to higher depositional flux and higher sediment discharge. The ratio of the MM inventory of 234Thex/production in the overlying water column of >2.5 in south inshore indicates that the sediment focusing resulted in the increased mass flux. The residence time of MM is estimated as 3–6 years both by mass balance of MM and 210Pbex in MM.
Enhanced warming of the Northwest Atlantic Ocean under climate change
Authors: Saba Vincent S. , Griffies Stephen M. , Anderson Whit G. , Winton Michael , Alexander Michael A. , Delworth Thomas L. , Hare Jonathan A. , Harrison Matthew J. , Rosati Anthony , Vecchi Gabriel A. , Zhang Rong
Published: December 2015

The Intergovernmental Panel on Climate Change (IPCC) fifth assessment of projected global and regional ocean temperature change is based on global climate models that have coarse (∼100 km) ocean and atmosphere resolutions. In the Northwest Atlantic, the ensemble of global climate models has a warm bias in sea surface temperature due to a misrepresentation of the Gulf Stream position; thus, existing climate change projections are based on unrealistic regional ocean circulation. Here we compare simulations and an atmospheric CO2 doubling response from four global climate models of varying ocean and atmosphere resolution. We find that the highest resolution climate model (∼10 km ocean, ∼50 km atmosphere) resolves Northwest Atlantic circulation and water mass distribution most accurately. The CO2 doubling response from this model shows that upper‐ocean (0–300 m) temperature in the Northwest Atlantic Shelf warms at a rate nearly twice as fast as the coarser models and nearly three times faster than the global average. This enhanced warming is accompanied by an increase in salinity due to a change in water mass distribution that is related to a retreat of the Labrador Current and a northerly shift of the Gulf Stream. Both observations and the climate model demonstrate a robust relationship between a weakening Atlantic Meridional Overturning Circulation (AMOC) and an increase in the proportion of Warm‐Temperate Slope Water entering the Northwest Atlantic Shelf. Therefore, prior climate change projections for the Northwest Atlantic may be far too conservative. These results point to the need to improve simulations of basin and regional‐scale ocean circulation.
Dry season streamflow persistence in seasonal climates
Authors: Dralle David N. , Karst Nathaniel J. , Thompson Sally E.
Published: December 2015

Seasonally dry ecosystems exhibit periods of high water availability followed by extended intervals during which rainfall is negligible and streamflows decline. Eventually, such declining flows will fall below the minimum values required to support ecosystem functions or services. The time at which dry season flows drop below these minimum values (Q*), relative to the start of the dry season, is termed the “persistence time” (
). The persistence time determines how long seasonal streams can support various human or ecological functions during the dry season. In this study, we extended recent work in the stochastic hydrology of seasonally dry climates to develop an analytical model for the probability distribution function (PDF) of the persistence time. The proposed model accurately captures the mean of the persistence time distribution, but underestimates its variance. We demonstrate that this underestimation arises in part due to correlation between the parameters used to describe the dry season recession, but that this correlation can be removed by rescaling the flow variables. The mean persistence time predictions form one example of the broader class of streamflow statistics known as crossing properties, which could feasibly be combined with simple ecological models to form a basis for rapid risk assessment under different climate or management scenarios.
Identifying long‐term empirical relationships between storm characteristics and episodic groundwater recharge
Authors: Tashie Arik M. , Mirus Benjamin B. , Pavelsky Tamlin M.
Published: December 2015

Shallow aquifers are an important source of water resources and provide base flow to streams; yet actual rates of groundwater recharge are difficult to estimate. While climate change is predicted to increase the frequency and magnitude of extreme precipitation events, the resulting impact on groundwater recharge remains poorly understood. We quantify empirical relations between precipitation characteristics and episodic groundwater recharge for a wide variety of geographic and land use types across North Carolina. We extract storm duration, magnitude, average rate, and hourly weighted intensity from long‐term precipitation records over periods of 12–35 years at 10 locations. Using time series of water table fluctuations from nearby monitoring wells, we estimate relative recharge to precipitation ratios (RPR) to identify statistical trends. Increased RPR correlates with increased storm duration, whereas RPR decreases with increasing magnitude, average rate, and intensity of precipitation. Agricultural and urban areas exhibit the greatest decrease in RPR due to increasing storm magnitude, average rate, and intensity, while naturally vegetated areas exhibit a larger increase in RPR with increased storm duration. Though RPR is generally higher during the winter than the summer, this seasonal effect is magnified in the Appalachian and Piedmont regions. These statistical trends provide valuable insights into the likely consequences of climate and land use change for water resources in subtropical climates. If, as predicted, growing seasons lengthen and the intensity of storms increases with a warming climate, decreased recharge in Appalachia, the Piedmont, and rapidly growing urban areas of the American Southeast could further limit groundwater availability.
A generalized complementary relationship between actual and potential evaporation defined by a reference surface temperature
Authors: Aminzadeh Milad , Roderick Michael L. , Or Dani
Published: December 2015

The definition of potential evaporation remains widely debated despite its centrality for hydrologic and climatic models. We employed an analytical pore‐scale representation of evaporation from terrestrial surfaces to define potential evaporation using a hypothetical steady state reference temperature that is common to both air and evaporating surface. The feedback between drying land surfaces and overlaying air properties, central in the Bouchet (1963) complementary relationship, is implicitly incorporated in the hypothetical steady state where the sensible heat flux vanishes and the available energy is consumed by evaporation. Evaporation rates predicted based on the steady state reference temperature hypothesis were in good agreement with class A pan evaporation measurements suggesting that evaporation from pans occurs with negligible sensible heat flux. The model facilitates a new generalization of the asymmetric complementary relationship with the asymmetry parameter b analytically predicted for a wide range of meteorological conditions with initial tests yielding good agreement between measured and predicted actual evaporation.
Computational Biology and Bioinformatics: Applications in Operations Research
Authors: Goulet Dave , Holder Allen
Published: December 2015

The innate optimal qualities exhibited by nature have fostered a host of applications for operations research in the biological sciences. The ongoing advance of the use of mathematical modeling and computing within the biological ethos has made dovetailing scientific pursuit with operations research a natural combination. Herein we present several biological problems in which either operations research has played a role or in which operations research is well poised to make an impact. The biological questions are selected to demonstrate the diverse scale over which biology drapes. Each problem begins with a terse biological introduction to establish the scientific setting, and the citations are selected to promote continued study.
Global adaptive finite‐time stabilization of a class of switched nonlinear systems with parametric uncertainty
Authors: Cai Mingjie , Xiang Zhengrong
Published: December 2015

This paper investigates the global adaptive finite‐time stabilization of a class of switched nonlinear systems, whose subsystems are all in p (p≤1) normal form with unknown control coefficients and parametric uncertainties. The restrictions on the power orders and the nonlinear perturbations are relaxed. By using the parameter separation technique, the uncertain parameters are separated from nonlinear functions. A systematic design procedure for a common state feedback controller and a switching adaptive law is presented by employing the backstepping methodology. It is proved that the closed‐loop system is finite‐time stable under arbitrary switching by utilizing the common Lyapunov function. Finally, with the application to finite‐time control of chemical reactor systems, the effectiveness of the proposed method is demonstrated. Copyright © 2015 John Wiley & Sons, Ltd.