bluuebunny/crossref_metadata_2025 huggingface dataset:
The competence system of Streptococcus anginosus and its use for genetic engineering
Authors: Bauer R. , Mauerer S. , Grempels A. , Spellerberg B.
Published: December 2017

Streptococcus anginosus is considered a human commensal but improvements in species identification in recent years have highlighted its role as an emerging pathogen. However, our knowledge about the pathogenicity mechanisms in this species is scarce. One reason for this is the lack of published genetic manipulation techniques in the S. anginosus group. To establish a novel mutation technique we investigated the competence system of S. anginosus and created a Cre‐recombinase‐based mutation method that allows the generation of markerless gene deletions in S. anginosus. In silico analysis of the competence system demonstrated that S. anginosus encodes homologues for the vast majority of genes that are known to be essential for the transformation of S. pneumoniae. Analysis of transformation kinetics confirmed that S. anginosus SK52 possesses an S. pneumoniae‐like competence development with a rapid increase of competence after treatment with Competence Stimulating Peptide (CSP), reaching a maximum transformation efficiency of 0.24% ± 0.08%. The combination of CSP‐induced transformation and the Cre‐lox system allows the efficient and fast creation of markerless gene deletions and will facilitate the investigation of the pathogenicity of S. anginosus on a genetic level.
Health‐care transition after Kawasaki disease in patients with coronary artery lesion
Authors: Kamiyama Hiroshi , Ayusawa Mamoru , Ogawa Shunichi , Saji Tsutomu , Hamaoka Kenji
Published: December 2017

Background

Discussion of health‐care transition (HCT) for adults with a childhood history of coronary artery lesions (CAL) after Kawasaki disease (KD) is important. A nationwide questionnaire survey was performed with support by the Japanese Society of Kawasaki Disease. The purpose of this study was to clarify the reality of HCT and loss to follow‐up in patients with CAL after KD.

Methods

The survey was emailed to 48 members of the Japanese Society of Kawasaki Disease from May to July 2014.

Results

Forty surveys were collected, giving a response rate of 83.3%. Sixty‐five percent of the respondents belonged to a university hospital. Approximately 90% of the respondents dealt with patients who needed HCT, and 55% had patients who completed HCT. Approximately 70% of the respondents considered that pediatricians should continue sharing HCT information with cardiologists. More than 95% of the respondents had a favorable or average impression of HCT care provided by cardiologists. The percentage of respondents who had loss to follow up for HCT was >40%.

Conclusion

Adult cardiologists began managing patients with CAL after KD in more than half of the institutes in this study. Pediatricians should construct a support program for better management of these patients and for cooperation with cardiologists to prevent loss to follow up.
Rotavirus infection as a frequent cause of neonatal fever
Authors: Kang Ha‐Na , Park Hyun Kyung , Lee Hyun‐Ju , Moon Jin‐Hwa , Oh Jae Won , Kim Chang‐Ryul
Published: December 2017

Background

Fever rather than diarrhea or vomiting was the most common symptom of neonatal rotavirus (RV) infection in our previous study. We investigated whether RV infection is a major cause of neonatal fever and compared the clinical characteristics of bacterial infection, viral infection and unknown causes of neonatal fever.

Method

We reviewed the electronic medical records of 48 newborns aged ≤28 days who were admitted to the Special Care Nursery of Hanyang University Guri Hospital for fever (≥38°C) from 2005 to 2009. All the newborns underwent complete blood count, urinalysis, C‐reactive protein, cultures of blood, urine, and cerebrospinal fluid as well as stool RV enzyme‐linked immunosorbent assay. Respiratory virus polymerase chain reaction for cough or rhinorrhea, and stool culture for diarrhea were also done.

Results

All the babies were term, with mean age 13 ± 8 days and peak body temperature 38.5 ± 0.5°C. The causes of neonatal fever were viral (44%), bacterial (10%) and unknown (46%). The viral infections included RV (n = 12), enterovirus (n = 6), respiratory syncytial virus (n = 2), and rhinovirus (n = 1). All the rotavirus genotypes were G4P[6]. Only three of 12 RV‐infected febrile newborns had diarrhea. The bacterial infections included three cases of urinary tract infection (Escherichia coli, n = 2; Klebsiella pneumoniae, n = 1), and two cases of sepsis complicated with meningitis (all Streptococcus agalactiae).

Conclusions

RV infection is the most common single cause of neonatal fever. It may be necessary to include stool RV tests for febrile newborns.
Big Data Analytics for Rapid, Impactful, Sustained, and Efficient (RISE) Humanitarian Operations
Authors: Swaminathan Jayashankar M.
Published: December 2017

There has been a significant increase in the scale and scope of humanitarian efforts over the last decade. Humanitarian operations need to be—rapid, impactful, sustained, and efficient (RISE). Big data offers many opportunities to enable RISE humanitarian operations. In this study, we introduce the role of big data in humanitarian settings and discuss data streams which could be utilized to develop descriptive, prescriptive, and predictive models to significantly impact the lives of people in need.
Molecular systematics and evolutionary history of catenotaeniid cestodes (Cyclophyllidea)
Authors: Haukisalmi Voitto , Ribas Alexis , Junker Kerstin , Spickett Andrea , Matthee Sonja , Henttonen Heikki , Jrijer Jamel , Halajian Ali , Anders Jason L. , Nakao Minoru
Published: December 2017

Phylogenetic relationships, evolutionary history and systematics of tapeworms of the family Catenotaeniidae were studied using nucleotide sequences of the partial 28S nuclear rDNA (ca. 1,500 bp) and mitochondrial 12S–16S DNA (ca. 820 bp) genes. The tapeworm material consists of 29 species, including type species of the genera Catenotaenia Janicki, 1904, Catenotaenioides Haukisalmi, Hardman and Henttonen, 2010, Pseudocatenotaenia Tenora, Mas‐Coma, Murai and Feliu, 1980, Skrjabinotaenia Akhumyan, 1946, Meggittina Lynsdale, 1953, and Hemicatenotaenia Tenora, 1977. The basal phylogenetic structure of the Catenotaeniidae remains unresolved, but it is shown that most of the catenotaeniids in Eurasia and Africa comprise a large clade represented by species of Catenotaenia, Catenotaenioides, Skrjabinotaenia and Meggittina, parasitizing murid, cricetid, nesomyid and sciurid rodents. The results suggest that the divergence and early radiation of this clade have occurred in murid rodents (represented by Apodemus spp. and Mus musculus in the present material) in western Eurasia, followed by colonization of Africa, most likely independently of the colonization of their murid hosts between these continents. There is very little evidence of cophylogeny between hosts and parasites, suggesting that host transfers have played a major role in the divergence of catenotaeniids. In Africa, catenotaeniids have radiated in other murid and nesomyid rodents, and later colonized Madagascar and recolonized Eurasia. The results also show that the subfamily Skrjabinotaeniinae (including Skrjabinotaenia and Meggittina) is monophyletic, but the Catenotaeniinae (including Catenotaenia, Catenotaenioides, Pseudocatenotaenia and Hemicatenotaenia) is clearly non‐monophyletic. In addition, the genera Catenotaenia and Skrjabinotaenia were both found to be non‐monophyletic. Based on the phylogenetic and morphological evidence, several taxonomical changes, mainly new combinations, are proposed. Overall, the present results suggest that the family Catenotaeniidae is in need of major systematic revision.
Creating Awareness of Sexual Abuse in Children with Special Education Needs: Depending on the Opinions of Teachers of the Mentally Handicapped
Authors: Büyükbayraktar Çağla Girgin , Er Rukiye Konuk , Kesici Şahin
Published: December 2017

The purpose of this research is to determine what students and families should do in order to prevent sexual abuse in students who need special education, depending on the opinions of teachers of mentally handicapped students. The qualitative research technique was used in this research. The study population of the research consisted of the teachers of mentally handicapped individuals working in Turkey/Konya province. The study population included 35 teachers. Semi-structure interview method was used as data collection method in collecting data in the research. According to the results, it is evident that individuals ought to be taught about their private parts, private parts in their bodies, and they ought to be made conscious about the fact that no one can touch these private parts in order to raise awareness about sexual abuse in individuals with special education needs. In order to stop sexual abuse by raising awareness in families of individuals with special education needs, it is necessary for families to acquire skills in terms of knowing their children, determining their needs and consulting an expert periodically. In order to raise awareness in the community about the sexual abuse in individuals with special education needs, the teachers express that all families should be trained, seminars should be organized on the issue and media ought to do its part to create awareness.
Effects of the Patience Training Program on Patience and Well-Being Levels of University Students
Authors: Bülbül Ayşe Eliüşük , Izgar Gökhan
Published: December 2017

In this study, the effect of patience training on patience and well-being levels of university students was examined. The sample group of the study consisted of 1.2.3. and 4th grade students with a total of 30 students from Konya Necmettin Erbakan University, Ereğli Education Faculty. For the collection of data, the Patience Scale developed by Schnitker (2010) and adapted to Turkish by Eliüşük and Arslan (2016) and the PERMA Well-being Scale developed by Kern (2015) and adapted to Turkish by Eliüşük (2016) was used. The measuring tools were applied to the experimental and control groups three times; the first before, the second one week after the and third three months after the end of the application. In the study, a patience education training consisting of 10 sessions was applied to the experimental group. No training was given to the control group. The Mann-Whitney U test and the Wilcoxon tests were used in the analysis of the data. As a result of the analyzes made at the end of the practice; significant differences where observed in individuals patience levels but no meaningful changes were seen in the well-being levels.
Afectos y conductas sexuales en adolescentes: diferencias y semejanzas en dos culturas, España y Colombia
Authors: López Félix , Carcedo Rodrigo J. , Fernández Rouco Noelia , Caballero María-Claudia
Published: December 2017

Este trabajo pretende identificar las posibles diferencias de género en

afectos y conductas sexuales de España y Colombia. La muestra total fue

de 508 participantes de centros de educación secundaria, 270 en España

y 238 en Colombia, de edades entre los 15 y 18 años y con una media de

edad de 16.4 años. Los resultados obtenidos muestran un doble patrón en

varones y mujeres, tanto en España como en Colombia, especialmente en

relación a los afectos sexuales y no tanto en las conductas sexuales.
Análisis psicométrico del test de dependencia de videojuegos (TDV) en población peruana
Authors: Salas Edwin , Merino César , Chóliz Mariano , Marco Clara
Published: December 2017

El objetivo del presente trabajo es validar en población peruana, el

Test de Dependencia de Videojuegos (TDV) (Chóliz & Marco, 2011).

Los resultados obtenidos demuestran que se trata de una herramienta

confiable y válida. Se encontró una sola estructura factorial, en lugar de

cuatro dimensiones, como plantearon los autores del TDV. Este factor

podría denominarse genéricamente: adicción a videojuegos, y podría

servir como evidencia de la existencia de este trastorno, que coincidiría

con el denominado ‘Trastorno de Juego por Internet’, que aparece en la

Sección III del DSM-5. Los resultados hallados se discuten en relación a lo

planteado por Chóliz y Marco (2011), en lo que se refiere a las diferencias

en cuanto a sexo, edad y la estructura interna del instrumento.
¿Cuál es el nivel de desarrollo esperable para un niño con síndrome de Down en sus primeros años de vida?
Authors: Rodriguez Barrera Juan Carlos , Chaves Castaño Liliana
Published: December 2017

El síndrome de Down es la causa genética más frecuente de discapacidad

vinculada con el desarrollo. La falta de valores normativos para los

niños que padecen este trastorno, dificulta una valoración temprana

y seguimiento del curso evolutivo. El objetivo del presente artículo es

describir el perfil evolutivo de estos niños durante los primeros tres

años de vida. Se realizó un estudio de cohorte de tipo prospectivo

durante 9 años, en el cual se incluyeron 156 niños menores de 37

meses. Ellos tuvieron 528 evaluaciones con la "Escala Abreviada del

Desarrollo" (EAD-1), una prueba válida y confiable estandarizada en

Colombia para valorar el nivel evolutivo en niños menores de 6 años. Se

establecieron los cocientes de desarrollo por trimestres, valores percentil,

las variaciones entre las áreas evaluadas, las curvas evolutivas estudiadas

en cada área y los períodos más críticos en los diferentes semestres. Estos

valores posibilitarán el seguimiento al curso evolutivo de estos niños, la

identificación temprana de las áreas de mayor vulnerabilidad y necesidad

de intervención, la evaluación del impacto de acciones terapéuticas o

programas de estimulación, y la orientación a los padres y agentes sociales

y de salud vinculados al desarrollo y la supervivencia del niño y la niña.
Desarrollo de la Imagen corporal, la autoestima y el autoconcepto físico al finalizar la Educación Primaria
Authors: Palomares Cuadros Juan , Cuesta Santos Jóse Manuel , Estévez Díaz Manuel , Torres Campos Beatriz
Published: December 2017

En este trabajo se analiza la relación entre la satisfacción con la imagen

corporal, la autoestima y el autoconcepto físico. Los participantes fueron

310 alumnos, de 5º y 6º de Educación Primaria, y 22 profesores en

activo, de la zona educativa Motril-Costa (España). Como técnicas

cuantitativas, se utilizaron: el Cuestionario de Siluetas Corporales,

Cuestionario de Autoconcepto Físico y la Escala de Autoestima de

Rosenberg. Como técnica cualitativa, se utilizó la entrevista semiestrucutrada.

Los resultados muestran que difiere la imagen que tienen

y que les gustaría tener. También se aprecia que los chicos tienen un

mayor nivel de autoestima. Son las chicas las que se consideran menos

hábiles para realizar actividad física y disfrutan en menor medida de estas

actividades.
Escala de Calidad de Vida Familiar: validación y análisis en población chilena
Authors: Bello Escamilla Natalia Verónica , Rivadeneira Joucelyn , Díaz Martínez Ximena , Concha-Toro Marcela , Soto Caro Ariel
Published: December 2017

El propósito de este estudio es presentar la validación de la Escala de

Calidad de Vida Familiar en población chilena y analizar las dimensiones

de este instrumento a través del mapa de área crítica. Se utilizó un estudio

transversal, correlacional y causal en 316 familias. Se aplicó la versión

española de la Escala de Calidad de Vida Familiar. Se condujo un análisis

factorial exploratorio y confirmatorio. Los resultados indicaron que el

alpha de Cronbach para la categoría de Importancia fue de 0.884 y para

Satisfacción fue de 0.891. El análisis factorial exploratorio encontró cinco

dimensiones para ambas categorías, y el análisis factorial confirmatorio

mostró cargas mayores a 0.5 para cada dimensión. Respecto a la validez

discriminante, las cargas cruzadas se movieron entre 0.64 a 0.97 para

Importancia y 0.62 a 0.98 para Satisfacción. En cuanto a la validez

convergente, cada dimensión alcanzó una varianza extraída sobre 0.5. Las

conclusiones del estudio indican que el instrumento resultó ser confiable

y válido para medir aspectos de la calidad de vida familiar en población

chilena. Posee altos niveles de consistencia interna y una adecuada validez

discriminante y convergente.
Evaluación de la imagen corporal en mujeres con cáncer de mama: una revisión sistemática
Authors: Figueroa Varela Ma. del Rocío , Valadez Sierra María de los Dolores , Rivera Heredia María Elena , Montes Delgado Roberto
Published: December 2017

La imagen corporal (IC) es la representación subjetiva de la percepción,

evaluación, valoración y vivencia del cuerpo que proporciona el sentido

de sí mismo como una totalidad. Es afectada cuando existen enfermedades

oncológicas que implican cambios corporales. En esta revisión sistemática

se identificaron instrumentos susceptibles de usarse en Latinoamérica

para evaluar la IC de mujeres con cáncer de mama, analizando 34

artículos publicados en inglés y español del periodo 2004-2014 en

bases de libre acceso. Instrumentos originados en Europa y Estados

Unidos, tales como la Escala de Imagen Corporal de Hopwood y

el módulo QLQ BR 23, desarrollado por la Organización Europea

para Investigación y Tratamiento en Cáncer (EORTC), con buenas

características psicométricas de validez y confiabilidad, se han utilizado en

población latinoamericana. Se valora cómo la IC de mujeres con cáncer

de mama afecta su sexualidad, las relaciones de pareja, su autoestima, los

estilos de afrontamiento y calidad de vida.
Evaluación psicométrica de la escala de felicidad de Lima en una muestra mexicana
Authors: Rodríguez-Hernández Gabriela , Domínguez-Zacarías Galileo , Escoto Ponce de León María del Consuelo
Published: December 2017

bajas puntuaciones en prácticamente todos los elementos que proveen

bienestar, y requiere de indicadores psicosociales que expliquen la

felicidad de los mexicanos. El objetivo de este estudio fue determinar

las propiedades psicométricas de la escala de felicidad de Lima (EFL)

en una muestra heterogénea mexicana. La EFL considera la felicidad

como un comportamiento multidimensional con una importante carga

cultural para población latina. Se realizaron análisis factorial exploratorio

y análisis factorial confirmatorio mediante el método de ecuaciones

estructurales. Los estudios se efectuaron con dos muestras heterogéneas

de 600 mexicanos cada una. Los resultados obtenidos llevaron a identificar

un modelo bifactorial donde el afecto positivo correlaciona positivamente

con la satisfacción con la vida.
Incorporación del mindfulness en el aula: un estudio piloto con estudiantes universitarios
Authors: Cuevas-Toro Ana María , Díaz-Batanero Carmen , Delgado-Rico Elena , Vélez-Toral Mercedes
Published: December 2017

El objetivo del estudio fue analizar los efectos de un programa breve

de mindfulness adaptado al contexto del aula, en relación con el nivel

de mindfulness (MAAS), evitación experiencial (AAQ-II), ansiedad

(STAI) y satisfacción vital (SWLS). La muestra estuvo conformada por

115 estudiantes universitarios. Tras la participación en el programa, los

estudiantes aumentaron significativamente los niveles de satisfacción vital

y ansiedad estado, no se encontraron diferencias en el resto de variables.

Sin embargo, el aumento de la satisfacción vital se relacionó con el

aumento del nivel de mindfulness al final del programa (coincidiendo

con el inicio de los exámenes). En conclusión, un programa breve de

mindfulness mejora la satisfacción vital, aun en un período de alto nivel

de ansiedad como es el periodo de exámenes.
The Role of Dispositional Flow’s Dimensions in the Prediction of Intention to be Physically Active in Adolescents
Authors: Franco Evelia , Coterón Javier , Gómez Valeria , Pérez-Tejero Javier
Published: December 2017

Enmarcado en la teoría del flow, este estudio pretende a) comprobar las diferencias en las dimensiones del flow disposicional yen la intención futura de realizar actividad física (IF) según el nivel de AF y b) estudiar el papel predictivo de dichas dimensiones sobre la IF. La muestra estuvo compuesta por 1076 estudiantes de educación física y se segmentó según el nivel actual de AF. Los sujetos que mostraron mayores niveles de AF presentaron valores más elevados en todas las dimensiones. Los análisis de regresión por pasos indicaron que la experiencia autotélica se asoció con IF en todos los participantes. Además, en el grupo de baja actividad el equilibrio percibido entre el reto y la habilidad emergió como predictor mientras que en el grupo de alta actividad, tanto la sensación de control como la percepción de objetivos claros resultaron significativos en la explicación de la IF. Los resultados sugieren que la implementación en clases de EF de diferentes estrategias para mejorar la disposición a experimentar el flow, puede aumentar la IF.
Conducta violenta en adolescentes escolarizados: un modelo estructural predictivo
Authors: Bonilla Castillón Claudia Elizabeth , Nuñez Fadda Silvana Mabel , Domínguez Mora Raquel , Callejas Jerónimo Juan Evaristo
Published: December 2017

El objetivo del presente estudio fue analizar la participación de los adolescentes en conductas violentas a partir de un modelo estructural, en una muestra aleatoria y estratificada de 1498 estudiantes de 5º y 6º de primaria, y de los tres niveles de secundaria de escuelas públicas de Puerto Vallarta, Jalisco, México. Se utilizaron cuestionarios de auto-informe con respuestas Likert, midiendo violencia escolar, funcionamiento familiar y actitud hacia la autoridad. Las conductas violentas correlacionan negativamente con el buen funcionamiento familiar (valores altos de unión/ apoyo). El funcionamiento familiar correlacionó negativamente con la conducta violenta de forma indirecta, a través de la actitud hacia la autoridad institucional y la transgresión de normas. Finalmente se discuten los resultados.
Resiliencia y rendimiento escolar en adolescentes de Lima y de Santiago de Chile de sectores vulnerables
Authors: Villalta Paucar Marco Antonio , Delgado Vásquez Ana Esther , Escurra Mayaute Luis Miguel , Torres Acuña William
Published: December 2017

El objetivo del estudio es proponer instrumentos de medición de la resiliencia relacionada al rendimiento escolar válida para adolescentes y jóvenes de sectores sociales vulnerables de zonas urbanas de dos países latinoamericanos. El método de investigación está basado en el análisis del comportamiento estadístico de los ítems y dimensiones de la resiliencia de la escala SV-RES en 764 adolescentes de zonas urbanas vulnerables de Lima-Perú y 1,145 de Santiago de Chile con alto y bajo rendimiento escolar de sectores sociales de alta vulnerabilidad social. Se realizó Análisis Factorial Exploratorio (AFE) y el análisis de validez convergente y discriminante. Los resultados sugieren nuevas dimensiones de la resiliencia vinculada al rendimiento académico diferenciadas para adolescentes de Lima y de Santiago de Chile.
Síntomas de Depresión en Hombres
Authors: Londoño Pérez Constanza , Peñate Castro Wenceslao , González Rodríguez Manuel
Published: December 2017

El objetivo de este estudio era identificar si existen sisntomas de depresión en hombres que no se encuentran descritos en los sistemas nosológicos disponibles. Para ello se estudia una muestra clínica, conformada por 59 hombres y 59 mujeres entre los 18 y los 65 años con diagnóstico de depresión previo, y por 59 hombres y 59 mujeres sin depresión usados como grupo control. Para evaluar Depresión se usó Cuestionario de Depresión en Hombres (CDH) y la Entrevista MINI (Mini International Neuropsychiatric Interview). Para los análisis psicométricos se usó el Modelo de Rasch desde la Teoría de Respuesta al Ítem y análisis comparativos multivariados. Se concluye que los hombres se deprimen de forma significativamente diferente de las mujeres y que parte de los síntomas identificados no son considerados en los sistemas nosológicos vigentes.
Undershoots in the Heat Transfer Coefficient and Friction-Factor Distributions in the Entrance Region of Turbulent Pipe Flows
Authors: Sparrow Eph M. , Gorman John M. , Bryant Daniel B.
Published: December 2017

Heat transfer coefficients for turbulent pipe flow are typically envisioned as axially varying from very high values at the pipe inlet to a subsequent monotonic decrease to a constant fully developed value. This distribution, although well enshrined in the literature, may not be universally true. Here, by the use of high accuracy numerical simulation, it was shown that the initially decreasing values of the coefficient may attain a local minimum before subsequently increasing to a fully developed value. This local minimum may be characterized as an undershoot. It was found that whenever a turbulent flow laminarizes when it enters a round pipe, the undershoot phenomenon occurs. The occurrence of laminarization depends on the geometry of the pipe inlet, on fluid-flow conditions in the upstream space from which fluid is drawn into the pipe inlet, on the magnitude of the turbulence intensity, and on the Reynolds number. However, the presence of the undershoot does not affect the fully developed values of the heat transfer coefficient. It was also found that the Fanning friction factor may also experience an undershoot in its axial variation. The magnitude of the heat transfer undershoot is generally greater than that of the Fanning friction factor undershoot.
Effects of Surface Roughness and Bend Geometry on Mass Transfer in an S-Shaped Back to Back Bend at Reynolds Number of 200,000
Authors: Wang D. , Ewing D. , Ching C. Y.
Published: December 2017

Experiments were performed to investigate the local development of roughness and its effect on mass transfer in an S-shaped bend at Reynolds number of 200,000. The tests were performed over four consecutive time periods using a 203-mm-diameter test section with a dissolving gypsum lining to water in a closed flow loop at a Schmidt number of 1200. The surface roughness and the mass transfer over the test periods were measured using X-ray computed tomography (CT) scans of the surface. Two regions of high mass transfer are found: along the intrados of the first and second bends. The surface roughness in these two regions, characterized by the height-to-spacing ratio, grows more rapidly than in the upstream pipe. There is an increase in the mass transfer with time, which corresponds well with the local increase in the height-to-spacing ratio of the roughness. The two regions of high mass transfer enhancement in the bend can be attributed to both a roughness effect and a flow effect due to the bend geometry. The geometry effect was determined by normalizing the local mass transfer with that in a straight pipe with equivalent surface roughness. The mass transfer enhancement due to the geometry effect was found to be relatively constant for the two high mass transfer regions, with a value of approximately 1.5.
Core-Based Evaluation of Associative Polymers as Enhanced Oil Recovery Agents in Oil-Wet Formations
Authors: Askarinezhad Reza , Hatzignatiou Dimitrios Georgios , Stavland Arne
Published: December 2017

Linear coreflood experiments are performed at 60 °C to test the effectiveness of a low molecular weight associative polymer as a displacing agent, and its ability to enhance oil recovery on chemically treated oil-wet Berea cores. Polymer injection tests revealed high mobility reductions (resistance factor (RF)) and reduced remaining oil saturations. Results obtained suggest that the incremental oil production is due to the high mobility reduction, as reported previously for water-wet porous media. The reduced remaining oil saturation is a function of the injected associative polymer treatment volume. Polymer mobility reduction is highly affected by the injected polymer velocity; this reduction is observed to be more significant at the lower velocity spectrum. Therefore, the established incremental oil production, even at reduced polymer injection rates (lower capillary numbers), could be explained by the increased mobility reduction. A correlation for the velocity-dependent mobility reduction is developed. Results are in agreement with previously reported ones in water-wet media and related to the enhanced oil recovery (EOR) nature of the injected associative polymer as opposed to the traditional mobility control of other polymer types. During injection, a column of oil-polymer emulsion is formed gradually in the separator causing operational difficulties and introducing produced fluid measurement (and core fluid saturations) uncertainties. Produced oil/water emulsion polymer volume content is used to correct overestimated oil production attributed to measurement uncertainties. Real-time resistivity measurements could also be a valuable tool for both fluids saturation monitoring and improved core fluids saturation evaluation in flooded porous media.
Modeling of Two-Phase Heat Exchangers With Zeotropic Fluid Mixtures
Authors: Gomse D. , Kochenburger T. M. , Grohmann S.
Published: December 2017

Heat exchangers are important components in many engineering applications. This paper proposes a numerical two-phase heat exchanger model with simultaneous heat transfer and pressure drop calculations. The presented model provides a modeling framework compatible with numerous different correlations for both single- and two-phase flow of pure fluids and fluid mixtures. Furthermore, it considers nonconstant fluid properties as well as longitudinal heat conduction and parasitic heat loads, which is particularly relevant in mixed refrigerant cycles for cooling of low-temperature applications. The governing equations are derived and the solution strategy is presented, followed by the model validation against analytical solutions in the corresponding limits. Finally, an exemplary heat exchanger is analyzed using both homogeneous and separated flow models, and the results are compared with experimental data from literature.
Observer Design for a Wellbore Drilling System With Downhole Measurement Feedback
Authors: Tian Dongzuo , Song Xingyong
Published: December 2017

The increasingly complex oil and gas wellbore condition and the need of drilling in more challenging downhole environments motivate rising research on the drilling control system based on real-time state feedback or measurements from the bottom of the wellbore. However, due to the complex downhole condition and cost-viability, mud pulse telemetry is normally used in this industry to transmit the downhole measurements to the surface, which can cause a large data communication delay as a result of its low bandwidth and slow mud pulse transmission. Since the major drilling control is on the surface, an observer is required to estimate the real-time states of the drilling dynamics as well as the downhole condition, based on the delayed downhole measurement. In this study, we first construct a drilling system dynamics model with coupled axial and torsional dynamics. Then, with the existence of a large output measurement delay, two chain-observer design strategies are introduced for the case of slowly varying control inputs and that of fast-varying control inputs, respectively. The effectiveness of the proposed observer design methods is shown through numerical results.
Multisource Data Fusion for Classification of Surface Cracks in Steel Pipes
Authors: Mustapha Samir , Braytee Ali , Ye Lin
Published: December 2017

This paper focuses on the development and validation of a robust framework for surface crack detection and assessment in steel pipes based on measured vibration responses collected using a network of piezoelectric (PZT) wafers. The pipe structure considered in this study contained multiple progressive cracks occurring at different locations and with various orientations (along the circumference or length). The fusion of data collected from multiple PZT wafers was investigated based on two approaches: (a) combining the raw data from all sensors before establishing a statistical model for damage classification and (b) combining the features from each sensor after applying a multiclass support vector machine recursive feature elimination (MCSVM-RFE), for dimensionality reduction, and taking the union of discriminative features among the different sources of data. A MCSVM learning algorithm was employed to train the data and generate a statistical classifier. The dataset consisted of ten classes, consisting of nine damage cases and the healthy state. The accuracy of the prediction based on the two fusion approaches resulted in a high accuracy, exceeding 95%, but the number of features needed to enrich the accuracy (95%) differed between the two approaches. Furthermore, the performance and the precision in the prediction of the classifier were evaluated when the data from only a single sensor was used compared with the combined data from all the sensors within the network. Very promising results in the classification of damage were obtained, based on the case study that included multiple damage scenarios with different lengths and orientations.
Modeling Dry Wear of Piston Rod Sealing Elements of Reciprocating Compressors Considering Gas Pressure Drop Across the Dynamic Sealing Surface
Authors: Kaufmann A. , Lindner-Silwester T. , Antretter T.
Published: December 2017

The wear of dynamic sealing elements, i.e., elements that seal against a moving counter-surface, is highly complex. In dry-running reciprocating compressors, these sealing elements, commonly referred to as packing rings, have to seal the compressed gas against the environment along the reciprocating rod. Since the packing rings' seal effect arises from the differential pressure to be sealed, it is of paramount importance to take into account the gas pressure drop across the dynamic sealing surface. This paper presents a numerical model that allows us to calculate how the wear of such a packing ring evolves with time. An analytical solution is used to verify the numerical model.
Familial risks for gallstones in the population of Sweden
Authors: Hemminki Kari , Hemminki Otto , Försti Asta , Sundquist Kristina , Sundquist Jan , Li Xinjun
Published: December 2017

Objectives

Gallstone disease (cholelithiasis) has a familial component, but detailed data on the modification of familial risk are lacking. Using nationwide hospital and population records, we aimed to determine detailed familial risks for medically diagnosed gallstone disease.

Design

Subjects were obtained from the Multigeneration Register, which contains family data on the Swedish population, and patients with gallstone disease were identified from the Hospital Discharge Register (1964–2015) and the Outpatient Register (2001–2015). Standardised incidence ratios (SIRs) were calculated as the ratio of observed to expected number of cases.

Results

Gallstone disease was diagnosed in 660 732 patients, with an overall incidence of 131 per 100 000 person-years. Familial cases accounted for 36.0% of all patients with gallstone disease. Of these, 50.9% had a parental family history (SIR 1.62), 35.1% had a sibling history (SIR 1.75) and 14.0% had a parental+sibling history (SIR 2.58). Among a total of 54 630 affected siblings, 84.4% were sibling pairs (SIR 1.55). However, the remaining 15.6% of the affected siblings constituted the high-risk group of multiple affected siblings and an SIR >10; these persons accounted for 7.7% of all familial cases. The spousal risk was only slightly increased to 1.18.

Conclusions

Overall, the results point to the underlying genetic causes for the observed familial clustering, which may involve polygenic gene–environmental interactions for most familial cases but high-risk genes in close to 10% of cases. Family histories should be taken into account in the medical setting and used for counselling of at-risk individuals.
‘Nobody is after you; it is your initiative to start work’: a qualitative study of health workforce absenteeism in rural Uganda
Authors: Tweheyo Raymond , Daker-White Gavin , Reed Catherine , Davies Linda , Kiwanuka Suzanne , Campbell Stephen
Published: December 2017

Background

Published evidence on the drivers of absenteeism among the health workforce is mainly limited to high-income countries. Uganda suffers the highest rate of health workforce absenteeism in Africa, attracting attention but lacking a definitive ameliorative strategy. This study aimed to explore the underlying reasons for absenteeism in the public and private ‘not-for-profit’ health sector in rural Uganda.

Methods

We undertook an empirical qualitative study, located within the critical realist paradigm. We used case study methodology as a sampling strategy, and principles of grounded theory for data collection and analysis. Ninety-five healthcare workers were recruited through focus groups and in-depth interviews. The NVivo V.10 software package was used for data management.

Results

Healthcare workers’ absenteeism was explained by complex interrelated influences that could be seen to be both external to, and within, an individual’s motivation. External influences dominated in the public sector, especially health system factors, such as delayed or omitted salaries, weak workforce leadership and low financial allocation for workers’ accommodation. On the other hand, low staffing—particularly in the private sector—created work overload and stress. Also, socially constructed influences existed, such as the gendered nature of child and elderly care responsibilities, social class expectations and reported feigned sickness. Individually motivated absenteeism arose from perceptions of an inadequate salary, entitlement to absence, financial pressures heightening a desire to seek supplemental income, and educational opportunities, often without study leave.

Conclusion

Health workforce managers and policy makers need to improve governance efficiencies and to seek learning opportunities across different health providers.
Pharmacological interventions for preventing post-operative atrial fibrillation in patients undergoing cardiac surgery: a network meta-analysis protocol
Authors: Wang Xiaoqin , Yao Liang , Ge Long , Li Lun , Liang Fuxiang , Zhou Qi , Chen Yaolong , Wang Yongfeng , Yang Kehu
Published: December 2017

Introduction

Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery, and randomised clinical trials (RCTs) and systematic reviews have been conducted to compare and evaluate different pharmacological interventions for preventing POAF. This study aimed to explore the effect of different pharmacological interventions for prophylaxis against POAF after cardiac surgery using network meta-analysis (NMA).

Methods and analysis

A systematic search will be performed in PubMed, EMBASE and the Cochrane Library to identify RCTs, systematic reviews, meta-analyses or NMA of different pharmacological interventions for POAF. We will evaluate the risk of bias of the included RCTs according to the Cochrane Handbook V.5.1.0, and use GRADE to assess the quality of evidence. Standard pairwise meta-analysis, trial sequential analysis and Bayesian network meta-analysis will be used to compare the efficacy of different pharmacological interventions.

Ethics and dissemination

Ethics approval and patient consent are not required as this study is a meta-analysis based on published studies. The results of this NMA and trial sequential analysis will be submitted to a peer-reviewed journal for publication.

Protocol registration number

CRD42017067492.
Neighbourhood socioeconomic status and cross-sectional associations with obesity and urinary biomarkers of diet among New York City adults: the heart follow-up study
Authors: Elfassy Tali , Yi Stella S , Llabre Maria M , Schneiderman Neil , Gellman Marc , Florez Hermes , Prado Guillermo , Zeki Al Hazzouri Adina
Published: December 2017

Objective

To determine whether neighbourhood socioeconomic status (SES) is associated with body mass index (BMI), waist circumference (WC) and biomarkers of diet (urinary sodium and potassium excretion).

Design

A cross-sectional study.

Setting

The data reported were from the 2010 Heart Follow-up Study, a population-based representative survey of 1645 adults.

Participants

Community-dwelling diverse residents of New York City nested within 128 neighbourhoods (zip codes).

Primary and secondary outcome measures

BMI (kg/m2) and WC (inches) were measured during in-home visits, and 24-hour urine sample was collected to measure biomarkers of diet: sodium (mg/day) and potassium (mg/day), with high sodium and low potassium indicative of worse diet quality.

Results

After adjusting for individual-level characteristics using multilevel linear regressions, low versus high neighbourhood SES tertile was associated with 1.83 kg/m2higher BMI (95% CI 0.41 to 3.98) and 251 mg/day lower potassium excretion (95% CI −409 to 93) among women only, with no associations among men (P values for neighbourhood SES by sex interactions <0.05).

Conclusion

Our results suggest that women may be particularly vulnerable to the effects of a socioeconomically disadvantaged neighbourhood. Future neighbourhood research should explore sex differences, as these can inform tailored interventions.

Trial registration number

NCT01889589; Results.
Prevalence of mental ill health, traumas and postmigration stress among refugees from Syria resettled in Sweden after 2011: a population-based survey
Authors: Tinghög Petter , Malm Andreas , Arwidson Charlotta , Sigvardsdotter Erika , Lundin Andreas , Saboonchi Fredrik
Published: December 2017

Objectives

To estimate the prevalence of and associations between anxiety, depression, post-traumatic stress disorder (PTSD), low subjective well-being (SWB), potential traumas and postmigration stress among refugees from Syria resettled in Sweden.

Design

A cross-sectional and population-based questionnaire study based on a known and complete sample frame. The survey included multiple measures of mental ill health and factors of particular relevance for refugees. Weighted analyses were conducted to calculate representative prevalence rates and associations. Associations were investigated through a series of logistic regression analyses. All analyses were supplemented with robust 95% CIs.

Setting

Sweden.

Participants

A random sample of 1215 individuals (response rate 30.4%) from Syria aged 18–64 years that were granted residency in Sweden on grounds of asylum between 2011 and 2013.

Main outcome measures

Anxiety, depression, PTSD and low SWB were assessed through Hopkins Symptom Checklist, Harvard Trauma Questionnaire and WHO-5 Well-being Index, using established cut-offs.

Results

A majority of the participants met the criteria for at least one of the studied types of mental ill health, and the comorbidity was high. Depression was the most the common type with 40.2% (95% CI 36.9% to 43.3%), followed by low SWB with 37.7% (95% CI 34.8% to 40.1%), anxiety with 31.8% (95% CI 29.2% to 34.7%) and PTSD with 29.9% (95% CI 27.2% to 32.6%). Refugee-related potentially traumatic events (PTEs) experienced before or during migration was common as was substantial levels of postmigration stress. Most types of refugee-related PTEs, especially being exposed to interpersonal violence, and postmigration stress were associated with increased risks for anxiety, depression, low SWB and PTSD.

Conclusions

Mental ill health, in terms of anxiety, depression, low SWB and PTSD, are highly elevated and comorbid among refugees from Syria. Increased attention from multiple societal sectors to adequately support Syrian refugees’ mental health needs, promoting recovery and reducing postmigration stress are needed.
Pneumonia diagnosis in childhood and incidence of leukaemia, lymphoma and brain cancer: a Danish nationwide cohort study
Authors: Søgaard Kirstine Kobberøe , Farkas Dóra Körmendiné , Sørensen Henrik Toft
Published: December 2017

Objectives

There is an ongoing debate on the possible association between infections in early childhood and subsequent cancer risk, but it remains unclear if a hospital admission for infection is associated with risk of childhood cancer diagnosis. We examined if a hospital-based diagnosis of pneumonia was a clinical marker of the three most common childhood cancers.

Design

Population-based cohort study.

Setting

Denmark, hospital diagnoses, 1994–2013.

Methods

Using national health registries, we compared the observed incidence of leukaemia, lymphoma and brain cancer among 83 935 children with a hospital-based pneumonia diagnosis with that expected among children in the general population. We calculated absolute cancer risks and standardised incidence ratios (SIRs) as a measure of relative risk.

Results

The cancer SIRs were substantially increased during the first 6 months of follow-up; lymphoid leukaemia: 6.2 (95% CI 3.5 to 10.3); myeloid leukaemia: 14.8 (95% CI 6.0 to 30.6); Hodgkin’s lymphoma: 60.8 (95% CI 26.2 to 120), non-Hodgkin’s lymphoma: 15.9 (95% CI 5.2 to 37.2) and brain cancer: 4.4 (95% CI 1.9 to 8.7). The 6-month absolute risks of leukaemia, lymphoma and brain cancer were all low, reaching 0.05% when combined. An increased risk persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the 5-year absolute cancer risk was 0.14%.

Conclusions

The short-term incidence of leukaemia, lymphoma and brain cancer was higher than expected and persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the absolute cancer risk was low.
Assessment of endothelialization of aneurysm wall over time in a rabbit model through CD31 scoring
Authors: Kolumam Parameswaran Praveen , Dai Daying , Ding Yong-Hong , Gunderson Tina , Kallmes David F , Kadirvel Ramanathan
Published: December 2017

Background

Intracranial aneurysms represent a significant health concern and are poorly understood despite decades of research. Our study focused on understanding temporal patterns of endothelial cell distribution in different spatial locations within the aneurysm early after creation in a rabbit model.

Methods

Elastase induced saccular aneurysms were created in rabbits and harvested on day 1 (n=3) and after 2 (n=5), 4 (n=4), 8 (n=5), and 12 (n=6) weeks. Sham operated controls (n=3) were harvested on the same day. Aneurysm and control tissue samples were subjected to en face whole mount CD31 staining for endothelial cells. Semiquantitative scoring was performed on the basis of endothelial coverage of the vessel wall (proximal, middle, and distal portions of the aneurysm dome). Mixed effects models were used to assess the effect of time and aneurysm section on endothelial coverage.

Results

Aneurysmal segments were near completely de-endothelialized at 4 and 8 weeks but had re-endothelialized by 12 weeks. Compared with controls, aneurysms at all time points showed decreased endothelialization, but the difference was only significant compared with the 4 and 8 week groups. Both time (P=0.03) and aneurysm section (P=0.07) were significantly associated with the degree of endothelialization. Proximal locations showed increased endothelialization compared with distal locations (P=0.03).

Conclusion

In experimental aneurysms of rabbits, endothelial cells regress during the first month after creation, followed by ascending re-endothelialization that stays incomplete. These findings suggest that re-population of endothelial cells comes from resident cells in the adjacent parent artery and that deranged hemodynamics may affect full reconstitution of endothelial cells long term.