bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the standardized ileal digestible valine : lysine ratio on performance, milk composition and plasma indices of lactating sows
Authors: Xu Yetong , Zeng Zhikai , Xu Xiao , Tian Qiyu , Ma Xiaokang , Long Shenfei , Piao Meijing , Cheng Zhibin , Piao Xiangshu
Published: December 2016

To determine the effects of standardized ileal digestible (SID) valine : lysine ratio on the performance, milk composition and plasma indices of lactating sows, 32 Large White × Landrace sows (219.78 ± 7.15 kg body weight; parity 1.82 ± 0.62) were allotted to one of four dietary treatments with eight sows per treatment based on parity, back fat thickness and body weight. The sows were fed corn‐soybean meal‐based diets containing 63, 83, 103 or 123% SID valine : lysine from day 107 of gestation until day 28 of lactation. The average daily feed intake of sows and daily weight gain of piglets increased linearly (P < 0.05) while back fat loss decreased linearly (P < 0.05) as the SID valine : lysine ratio increased. All of the analyzed amino acids in sow colostrum and valine concentrations of sow and piglet plasma increased linearly (P < 0.05) with the increasing SID valine : lysine ratio. In conclusion, 88 and 113% dietary SID valine : lysine ratios were optimal to achieve minimum back fat loss and maximum piglet growth rate using a linear‐break point model which exceeds the requirement of 85% that is estimated by the National Research Council (2012).
Pharmacodynamic response profiles of anxiolytic and sedative drugs
Authors: Chen Xia , Broeyer Freerk , de Kam Marieke , Baas Joke , Cohen Adam , van Gerven Joop
Published: December 2016

Aim

Centrally‐acting acutely anxiolytic drugs, such as benzodiazepines, barbiturates and gabapentinoids, affect various central nervous system (CNS) functions, which reflects not only their anxiolytic effects but also neuropsychological side‐effects. To validate the pharmacodynamic biomarkers for GABA‐ergic anxiolytics, this study determined the pharmacodynamics of two anxiolytics and a nonanxiolytic control, and linked them to their anxiolytic and sedative effects, during an anxiety‐challenge study day.

Methods

Twenty healthy volunteers were randomized in this placebo‐controlled, double‐blind, four‐way cross‐over study with single‐dose alprazolam (1 mg), diphenhydramine (50 mg), pregabalin (200 mg) or placebo. The Neurocart was used between repeated fear‐potentiated startle assessments. Thus, the potential influence of anxiety on CNS pharmacodynamic markers could be examined.

Results

Compared to placebo, VAScalmness increased with alprazolam (2.0 mm) and pregabalin (2.5 mm) but not with diphenhydramine. Saccadic peak velocity (SPV) declined after alprazolam (−57 ° s–1) and pregabalin (−28 ° s–1), more than with diphenhydramine (−14 ° s–1); so did smooth pursuit. The average responses of SPV and smooth pursuit were significantly correlated with the drug‐induced increases in VAScalmness. The SPV‐relative responses of VASalertness, body‐sway and adaptive‐tracking also differed among alprazolam, pregabalin and diphenhydramine.

Conclusions

Compared with the antihistaminergic sedative diphenhydramine, alprazolam and pregabalin caused larger SPV reduction, which was correlated with simultaneous improvement of subjective calmness, during a study day in which anxiety was stimulated repeatedly. The different effect profiles of the three drugs are in line with their pharmacological distinctions. These findings corroborate the profiling of CNS effects to demonstrate pharmacological selectivity, and further support SPV as biomarker for anxiolysis involving GABA‐ergic neurons. The study also supports the use of prolonged mild threat to demonstrate anxiolytic effects in healthy volunteers.
Relaxin family peptides: structure–activity relationship studies
Authors: Patil Nitin A , Rosengren K Johan , Separovic Frances , Wade John D , Bathgate Ross A D , Hossain Mohammed Akhter
Published: December 2016

The human relaxin peptide family consists of seven cystine‐rich peptides, four of which are known to signal through relaxin family peptide receptors, RXFP1–4. As these peptides play a vital role physiologically and in various diseases, they are of considerable importance for drug discovery and development. Detailed structure–activity relationship (SAR) studies towards understanding the role of important residues in each of these peptides have been reported over the years and utilized for the design of antagonists and minimized agonist variants. This review summarizes the current knowledge of the SAR of human relaxin 2 (H2 relaxin), human relaxin 3 (H3 relaxin), human insulin‐like peptide 3 (INSL3) and human insulin‐like peptide 5 (INSL5).

Linked Articles

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc
Sitagliptin reduces inflammation, fibrosis and preserves diastolic function in a rat model of heart failure with preserved ejection fraction
Authors: Esposito Grazia , Cappetta Donato , Russo Rosa , Rivellino Alessia , Ciuffreda Loreta Pia , Roviezzo Fiorentina , Piegari Elena , Berrino Liberato , Rossi Francesco , De Angelis Antonella , Urbanek Konrad
Published: December 2016

Background and Purpose

Heart failure with preserved ejection fraction (HFpEF) is a systemic syndrome driven by co‐morbidities, and its pathophysiology is poorly understood. Several studies suggesting that dipeptidyl peptidase 4 (DPP4) might be involved in the pathophysiology of heart failure have prompted experimental and clinical investigations of DPP4 inhibitors in the cardiovascular system. Here we have investigated whether the DPP4 inhibitor sitagliptin affected the progression of HFpEF independently of its effects on glycaemia.

Experimental Approach

Seven‐week‐old Dahl salt‐sensitive rats were fed a high‐salt diet for 5 weeks to induce hypertension. Then the rats continued with the high‐salt diet and were treated with either sitagliptin (10 mg·kg−1) or vehicle for the following 8 weeks. Blood pressure and cardiac function were measured in vivo. Histochemical and molecular biology analyses of myocardium were used to assay cytokines, fibrotic markers, DPP4 and glucagon‐like peptide‐1 (GLP‐1)/GLP‐1 receptor.

Key Results

Treatment with sitagliptin attenuated diastolic dysfunction, reduced mortality and reduced cardiac DPP4 activity, along with increased circulating GLP‐1 and myocardial expression of GLP‐1 receptors. Myocardial levels of pro‐inflammatory cytokines (TNF‐α, IL‐6 and CCL2) were reduced. Sitagliptin treatment decreased the levels of endothelial NOS monomer, responsible for generation of ROS, while the amount of NO‐producing dimeric form increased. Markers of oxidative and nitrosative stress were decreased. Moreover, increased collagen deposition and activation of pro‐fibrotic signalling, inducing elevated myocardial stiffness, were attenuated by sitagliptin treatment.

Conclusions and Implications

Sitagliptin positively modulated active relaxation and passive diastolic compliance by decreasing inflammation‐related endothelial dysfunction and fibrosis, associated with HFpEF.

Linked Articles

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc
Effects of economics and demographics on global fisheries sustainability
Authors: Ding Qi , Wang Yali , Chen Xinjun , Chen Yong
Published: December 2016

A good understanding of social factors that lead to marine ecological change is important to developing sustainable global fisheries. We used balanced panel models and conducted cross‐national time‐series analyses (1970–2010) of 122 nations to examine how economic prosperity and population growth affected the sustainability of marine ecosystems. We used catches in economic exclusive zone (EEZ); mean trophic level of fishery landings (MTL); primary production required to sustain catches (expressed as percentage of local primary production [%PPR]); and an index of ecosystem overfishing (i.e., the loss in secondary production index [L index]) as indicators of ecological change in marine ecosystems. The EEZ catch, %PPR, and L index declined gradually after gross domestic product (GDP) per capita reached $15,000, $14,000, and $19,000, respectively, and MTL increased steadily once GDP per capita exceeded $20,000. These relationships suggest that economic growth and biodiversity conservation are compatible goals. However, increasing human populations would degrade marine ecosystems. Specifically, a doubling of human population caused an increase in the %PPR of 17.1% and in the L index of 0.0254 and a decline in the MTL of 0.176. A 1% increase in human population resulted in a 0.744% increase in EEZ catch. These results highlight the importance of considering social and economic factors in developing sustainable fisheries management policy.
Perceptual narrowing towards adult faces is a cross‐cultural phenomenon in infancy: a behavioral and near‐infrared spectroscopy study with Japanese infants
Authors: Kobayashi Megumi , Macchi Cassia Viola , Kanazawa So , Yamaguchi Masami K. , Kakigi Ryusuke
Published: December 2016

Recent data showed that, in Caucasian infants, perceptual narrowing occurs for own‐race adult faces between 3 and 9 months of age, possibly as a consequence of the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals of the same race of the caregiver. The neural correlates of this developmental process remain unexplored, and it is currently unknown whether perceptual tuning towards adult faces can be extended to other cultures. To this end, in the current study we tested the ability of 3‐ and 9‐month‐old Japanese infants to discriminate among adult and infant Asian faces in a visual familiarization task (Experiment 1), and compared 9‐month‐olds’ cerebral hemodynamic responses to adult and infant faces as measured by near‐infrared spectroscopy (NIRS) (Experiment 2). Results showed that 3‐month‐olds exhibit above‐chance discrimination of adult and infant faces, whereas 9‐month‐olds discriminate adult faces but not infant faces (Experiment 1). Moreover, adult faces, but not infant faces, induced significant increases in hemodynamic responses in the right temporal areas of 9‐month‐old infants. Overall, our data suggest that perceptual narrowing towards adult faces is a cross‐cultural phenomenon occurring between 3 and 9 months of age, and translates by 9 months of age into a right‐hemispheric specialization in the processing of adult faces.
The ‘ouR‐HOPE’ approach for ethics and communication about neonatal neurological injury
Authors: Racine Eric , Bell Emily , Farlow Barbara , Miller Steven , Payot Antoine , Rasmussen Lisa Anne , Shevell Michael I , Thomson Donna , Wintermark Pia
Published: December 2016

Predicting neurological outcomes of neonates with acute brain injury is an essential component of shared decision‐making, in order to guide the development of treatment goals and appropriate care plans. It can aid parents in imagining the child's future, and guide timely and ongoing treatment decisions, including shifting treatment goals and focusing on comfort care. However, numerous challenges have been reported with respect to evidence‐based practices for prognostication such as biases about prognosis among clinicians. Additionally, the evaluation or appreciation of living with disability can differ, including the well‐known disability paradox where patients self‐report a good quality of life in spite of severe disability. Herein, we put forward a set of five practice principles captured in the “ouR‐HOPE” approach (Reflection, Humility, Open‐mindedness, Partnership, and Engagement) and related questions to encourage clinicians to self‐assess their practice and engage with others in responding to these challenges. We hope that this proposal paves the way to greater discussion and attention to ethical aspects of communicating prognosis in the context of neonatal brain injury.
Relationship Lending and Firms’ Leverage: Empirical Evidence in Europe
Authors: Guida Roberto , Sabato Valentina
Published: December 2016

Using a novel measure of relationship lending based on the kind of information banks use to assess borrowers, we investigate the role of relationship lending in firms’ capital structure. Using a unique dataset of European manufacturing firms, we measure relationship lending based on three dimensions (closeness, soft information, exclusivity) and relate them to firms’ leverage. Overall our results support the hypothesis that supply factors matter. We find that the actual use of soft information increases leverage and only firms without soft information‐intensive relationships increase their leverage through multiple relationships. However, the effect of relationship lending on leverage varies across countries.
The effect of combined inositol hexakisphosphate and inositol supplement in streptozotocin‐induced type 2 diabetic rats
Authors: Foster Shadae R. , Omoruyi Felix O. , Bustamante Juan , Lindo Ruby L. A. , Dilworth Lowell L.
Published: December 2016

Inositol hexakisphosphate (IP6) and inositol both regulate insulin secretion, but their combined use in the management of diabetes deserves investigation. The combined effects of IP6 and inositol supplementation were investigated in streptozotocin‐induced type 2 diabetic rats. The following groups of rats were studied for 8 weeks: non‐diabetic control, non‐diabetic high‐fat diet control, diabetic untreated, diabetic rats treated with the combination of IP6 and inositol (650 mg/kg bw) and diabetic rats treated with glibenclamide (10 mg/kg bw). High‐fat diet and streptozotocin were used to induce type 2 diabetes mellitus in Sprague–Dawley rats. Body weight, blood glucose, glycated haemoglobin, insulin, serum leptin, HOMA‐insulin resistance scores, intestinal amylase activity, serum and faecal lipids and food and fluid consumption were measured. Treatment with the combination significantly reduced blood glucose (306 ± 53 mg/dl) and insulin resistance score (1.93 ± 0.45) compared with diabetic controls (522 ± 24 mg/dl and 5.1 ± 0.69 respectively). Serum leptin (2.8 ± 0.6 ng/dl) and faecal triglycerides (108 ± 8 mg/dl) were significantly increased in rats treated with the combination compared with the diabetic control (1.8 ± 0.06 ng/dl and 86 ± 4 mg/dl). Serum triglyceride (47 ± 5.1 mg/dl), total cholesterol (98 ± 3.2 mg/dl) and food intake (26 ± 0.3 g) were significantly reduced by 45%, 25% and 25%, respectively, in rats treated with the combination compared with the diabetic control. Inositol and IP6 combined supplementation may be effective in the management of type 2 diabetes mellitus and related metabolic disorders by regulating some aspects of lipid and carbohydrate metabolism.
Effects of air pollution exposure on glucose metabolism in Los Angeles minority children
Authors: Toledo‐Corral C. M. , Alderete T. L. , Habre R. , Berhane K. , Lurmann F. W. , Weigensberg M. J. , Goran M. I. , Gilliland F. D.
Published: December 2016

Objectives

Growing evidence indicates that ambient (AAP: NO2, PM2.5 and O3) and traffic‐related air pollutants (TRAP) contribute to metabolic disease risk in adults; however, few studies have examined these relationships in children.

Methods

Metabolic profiling was performed in 429 overweight and obese African‐American and Latino youth living in urban Los Angeles, California. This cross‐sectional study estimated individual residential air pollution exposure and used linear regression to examine relationships between air pollution and metabolic outcomes.

Results

AAP and TRAP exposure were associated with adverse effects on glucose metabolism independent of body fat percent. PM2.5 was associated with 25.0% higher fasting insulin (p < 0.001), 8.3% lower insulin sensitivity (p < 0.001), 14.7% higher acute insulin response to glucose (p = 0.001) and 1.7% higher fasting glucose (p < 0.001). Similar associations were observed for increased NO2 exposure. TRAP from non‐freeway roads was associated with 12.1% higher insulin (p < 0.001), 6.9% lower insulin sensitivity (p = 0.02), 10.8% higher acute insulin response to glucose (p = 0.003) and 0.7% higher fasting glucose (p = 0.047).

Conclusions

Elevated air pollution exposure was associated with a metabolic profile that is characteristic of increased risk for type 2 diabetes. These results indicate that increased prior year exposure to air pollution may adversely affect type 2 diabetes‐related pathophysiology in overweight and obese minority children.
Renegotiating Access to Shea Trees in Burkina Faso: Challenging Power Relationships Associated with Demographic Shifts and Globalized Trade
Authors: Rousseau Karen , Gautier Denis , Wardell D. Andrew
Published: December 2016

This paper uses an original integrated theoretical framework to reveal the mechanisms behind socio‐economic differentiation in the changing patterns of access to shea in western Burkina Faso, in the context of globalization of the shea nut trade and internal migrations from both the Mossi Plateau and the Sahelian zone. Based on more than 200 interviews, we unravel the complex dynamic mechanisms of changes in access to shea. We show that negotiations result in reduced access to shea for late comers as well as for people with a limited number of shea trees in their fields, since areas where shea is managed as a common‐pool resource are becoming less accessible. However, we also demonstrate that late comers are not powerless in the face of first comers’ claims to shea. Our results should help policy‐makers and project‐based activities concerning shea to focus more on issues related to access to this resource.
The Role of Agents and Brokers in the Market for Health Insurance
Authors: Karaca‐Mandic Pinar , Feldman Roger , Graven Peter
Published: December 2016

Health insurance markets in the United States are characterized by imperfect information, complex products, and substantial search frictions. Insurance agents and brokers play a significant role in helping employers navigate these problems. However, little is known about the relations between the structure of the agent/broker market and access and affordability of insurance. This article aims to fill this gap by investigating the influence of agents/brokers on health insurance offering decisions of small firms, which are particularly vulnerable to problems of financing health insurance. Using a unique membership database from the National Association of Health Underwriters together with a nationally representative survey of employers, we find that small firms in more competitive agent/broker markets are more likely to offer health insurance and at lower premiums. Moreover, premiums are less dispersed in more competitive agent/broker markets.
Associations of Trait Emotional Intelligence with Social Support, Work Engagement, and Creativity in Japanese Eldercare Nurses
Authors: Toyama Hiroyuki , Mauno Saija
Published: December 2016

Work‐related resources can be positive antecedents of employee work engagement (WE) and creativity. Although trait emotional intelligence (EI) and social support may be crucial resources in nursing, their relationships with WE and creativity remain unclear. Hence, with special focus on the role of trait EI, we examined this relationship by applying the job demands‐resources (JD‐R) model. The participants were 489 eldercare nurses in Japan (female: n = 401; male: n = 88; age = 39.5 ± 11.0 years). The results showed positive associations between EI and the other studied variables. Furthermore, moderated mediation analyses revealed that higher trait EI enhanced the positive association among the triad of social support, WE, and creativity. The findings provide additional evidence that, in nurses, trait EI may be a noteworthy personal resource for creativity in the relationship between social support and WE.
Dental caries and associated factors in twins with Down syndrome: a case report
Authors: Moreira Maurício José Santos , Schwertner Carolina , Dall'Onder Ana Paula , Klaus Natália Mincato , Parolo Clarissa Cavalcanti Fatturi , Hashizume Lina Naomi
Published: December 2016

Down syndrome (DS) is the most common genetic disorder in humans, but its incidence in monozygotic twins is extremely rare. The aim of this study was to determine the factors associated with dental caries in a pair of monozygotic twin girls with DS, where one had caries experience and the other did not. Clinical examination, salivary Streptococcus mutans (S. mutans) levels and their genotypic diversity, the biochemical composition of the dental biofilm, the frequency of sucrose consumption, and toothbrushing habits were assessed from the twin girls. Twin with caries experience showed higher levels of S. mutans in the saliva and lower concentrations of calcium, phosphate, and fluoride and higher concentrations of extracellular polysaccharides in the biofilm compared to her sister. Genotypic diversity of S. mutans was also higher in the twin with caries experience. Dental biofilm composition showed different patterns of cariogenicity between the two sisters, which may also by itself explain the difference in the dental caries between them.
Multi‐scale approach to mining significant spatial co‐location patterns
Authors: Deng Min , He Zhanjun , Liu Qiliang , Cai Jiannan , Tang Jianbo
Published: December 2016

Spatial co‐location pattern mining aims to discover a collection of Boolean spatial features, which are frequently located in close geographic proximity to each other. Existing methods for identifying spatial co‐location patterns usually require users to specify two thresholds, i.e. the prevalence threshold for measuring the prevalence of candidate co‐location patterns and distance threshold to search the spatial co‐location patterns. However, these two thresholds are difficult to determine in practice, and improper thresholds may lead to the misidentification of useful patterns and the incorrect reporting of meaningless patterns. The multi‐scale approach proposed in this study overcomes this limitation. Initially, the prevalence of candidate co‐location patterns is measured statistically by using a significance test, and a non‐parametric model is developed to construct the null distribution of features with the consideration of spatial auto‐correlation. Next, the spatial co‐location patterns are explored at multi‐scales instead of single scale (or distance threshold) discovery. The validity of the co‐location patterns is evaluated based on the concept of lifetime. Experiments on both synthetic and ecological datasets show that spatial co‐location patterns are discovered correctly and completely by using the proposed method; on the other hand, the subjectivity in discovery of spatial co‐location patterns is reduced significantly.
Warm‐reactive (immunoglobulin G) autoantibodies and laboratory testing best practices: review of the literature and survey of current practice
Authors: Ziman Alyssa , Cohn Claudia , Carey Patricia M. , Dunbar Nancy M. , Fung Mark K. , Greinacher Andreas , Stanworth Simon , Heddle Nancy M. , Delaney Meghan ,   and the Biomedical Excellence for Safer Transfusion (BEST) Collaborative
Published: December 2016

BACKGROUND

Warm‐reactive autoantibodies (WAAs) are the most common cause of autoimmune hemolytic anemia (AIHA) and can also be present without clinically significant hemolysis. WAAs complicate immunohematological testing, yet there is no commonly accepted approach to laboratory evaluation and red blood cell (RBC) selection.

STUDY DESIGN AND METHODS

We searched PubMed/Cochrane Central for articles that described testing methodology and blood selection for patients with WAAs. We developed a 31‐question survey regarding local practice for immunohematology testing and RBC selection in patients with WAAs (with or without AIHA).

RESULTS

Eighty‐six studies met the inclusion criteria and the aims of this review. Most of the literature was comprised of retrospective studies that often did not correlate laboratory results with clinical findings. Evidence‐based protocols to guide testing and RBC selection for transfusion in patients with WAAs are lacking. Individuals representing 54 laboratories completed the survey. The responses indicated that numerous methodologies are used to identify underlying alloantibodies: 75% of respondents use autoadsorption; in patients who have a recent history of transfusion, 76% of respondents use alloadsorption; 58% of respondents perform direct antiglobulin testing (DAT) each time the indirect antiglobulin test is positive; and 48% perform eluate studies at the initial identification of WAAs. Responding laboratories may use phenotyping (98%) or genotyping (80%) at some point in the work‐up. Seventy‐five percent of respondents provide phenotype‐matched or genotype‐matched RBCs for transfusion.

CONCLUSION

There is wide variability in immunohematology testing and RBC selection practices for patients who have WAAs (with or without AIHA). Future studies are needed to evaluate and compare the effectiveness of different testing algorithms and transfusion strategies.
Ciudadanía, representación política y territorio en la audiencia de Quito: entre el Pacto Solemne de 1812 y el censo poblacional de 1813
Authors: Cabrera Hanna Santiago
Published: December 2016

El artículo considera el Pacto Solemne promulgado por la Junta Superior de Gobierno de Quito, en 1812, y el censo dispuesto por Torivio Montes en 1813, como primer paso en la introducción de la Constitución de Cádiz en la audiencia de Quito, luego de la derrota del experimento juntista. Estos dos instrumentos normativos son apreciados en términos de los imaginarios de ciudadanía que forjaron y el tipo de representación política que intentaron instituir, en relación con la apelación al territorio como un elemento clave en las dinámicas institucionales de conformación de poderes locales con potenciales aspiraciones centralizadoras. Ambos instrumentos son considerados como herramientas de construcción de poderes centrales. 
La «escuela estallada»: diálogos entre dos nociones de práctica pedagógica
Authors: Saldarriaga Vélez Óscar
Published: December 2016

El Movimiento Pedagógico Colombiano que emergió en la década de 1980 lanzó una lucha por la recuperación de la Pedagogía como espacio identificador del oficio de maestro, y acuñó dos conceptos: el de saber pedagógico y el de práctica pedagógica, como instrumentos y objetos estratégicos de tal lucha. Tras cuarenta años del proceso, el primer concepto ha sido bien apropiado por los profesores, mientras que el segundo es usado sobre todo por los funcionarios del sistema  educativo. Para abordar esta paradoja, se ponen en diálogo y debate dos perspectivas de comprensión de la noción de práctica pedagógica: una de inspiración foucaultiana, desarrollada por Olga Zuluaga (Colombia), y otra de inspiración decertoniana, propuesta por Anne-Marie Chartier (Francia). Un diálogo figurado entre el autor y esta investigadora sirve como escenario para presentar los elementos convergentes y divergentes de estas dos perspectivas.
Luchas por el derecho a la salud, el caso del Sindicato Minero de Amagá y Angelópolis, Colombia 1937-1945
Authors: Gallo Óscar
Published: December 2016

En este artículo se analiza el caso del Sindicato Minero de Amagá y Angelópolis (Antioquia, Colombia). Mediante las actividades políticas de estos mineros se puede observar la legitimidad atribuida por los trabajadores al derecho a la salud. Los pliegos de peticiones y las solicitudes en el terreno de la salud registran el tránsito de la beneficencia al derecho de cada trabajador a enfermar, a ser protegido y asegurado durante la enfermedad y a restablecer su salud. Las acciones realizadas por estos mineros en el espacio político son ejemplo de las nuevas formas de canalizar las luchas por los derechos a través de las oportunidades que ofrece la legislación. Sus acciones, que no son ni aisladas ni solitarias, reflejan las actitudes del movimiento obrero de todo el país. 
Evaluación in vitro de la microfiltración de Enterococcus faecalis usando cinco técnicas de obturación / In Vitro Evaluation of Enterococcus faecalis Microleakage Using Five Obturation Techniques
Authors: Aragón Matamoros Silvia Elena , Guindos Moya Tomás Alberto , Meza González Yanina , Morales Herrera Diana , Perera Díaz María Alejandra , Rodríguez Ciódaro Adriana , Diez Ortega Hugo , Méndez De la Espriella Catalina
Published: December 2016

ABSTRACT. Background: The root canal filling technique named Hybrid-Mixed Condensation, combines the advantages of cold lateral and warm vertical condensation. The ability of avoiding microbial microleakage has not been proven. Purpose: To evaluate the differences of microbial microleakage using Enterococcus faecalis, in canals obturated with five different techniques: lateral, warm vertical, WaveOne® single cone, Guttacore®, and Hybrid-mixed condensation. Methods: 50 single-rooted human premolars extracted for orthodontic reasons were biomechanical prepared with primary file of WaveOne® system. Teeth were divided into 5 groups using different obturation techniques: single cone with WaveOne® Primary, lateral condensation using 2 % gutta-percha cones, Guttacore® 30, warm vertical condensation using down packing in a WaveOne® Primary cone and backfill with alpha gutapercha of Beefill®, and the hybrid mixed condensation modifying the lateral condensation with heat and a backfill using Beefill®. Enterococcus faecalis was inoculated in the coronal third and apices were immersed in brain heart infusion broth with phenol red incubated at 37 °C for 12 weeks. Microfiltration was determined with color change and turbidity of the medium. Specimens were observed by scanning electron microscopy. Results: Only 11 teeth (22 %) were positive for leakage. 46 % with single cone, 30 % with Guttacore®, 20 % with lateral condensation, 10 % with warm vertical condensation and no microleakage was found for Hybrid-Mixed Technique over the period of 12 weeks of study. Conclusion: Hybrid Mixed Technique showed to be the most efficient technique to get three-dimensional seal and prevent microbial contamination of canals in the endodontic therapy.
Uso de redes neuronales artificiales en predicción de morfología mandibular a través de variables craneomaxilares en una vista posteroanterior / Use of Artificial Neural Networks for Mandibular Morphology Prediction through Craniomaxillar Variables...
Authors: Niño Sandoval Tania Camila , Guevara Pérez Sonia Victoria , González Fabio Augusto , Jaque Robinson Andrés , Infante Contreras Clementina
Published: December 2016

Background: Predicting mandibular morphology is important in facial reconstruction for forensic purposes as in orthodontics and maxillofacial surgery. This process has been performed through parametric and linear methods based on Caucasian populations. Also, these analyzes are performed on lateral cephalograms, but a prediction from a posteroanterior view is not taken into account. Purpose: To predict through artificial neural networks the mandibular morphology using craniomaxillary measures in posteroanterior radiographs. Methods: 229 standardized posteroanterior radiographs from Colombian young adults of both sexes were collected. Coordinates of craniofacial skeletal landmarks were used to create mandibular and craniomaxillary measures. 17 predictor craniomaxillary input variables were selected, measuring widths, heights, and angles. Similarly, 13 mandibular measures were selected to be predicted, considering both the right and left sides. Artificial neural networks were used for the prediction process and it was evaluated by a correlation coefficient using a ridge regression between real value and the predicted value. Results: The results found in the model were significant especially for 5 variables of morphological importance in the forensic field: right mandibular ramus (Cdd-God), bigonial width (Goi-God), bicondylar width (Cdi-Cdd), and distance between the condyles to the menton (Cdd-Me and Cdi-Me). Conclusions: An important prediction capacity in 5 measures of forensic importance in patients with skeletal Class I, Class II and Class III was found in both sexes.
Learning by Doing on Computational Fluid Dynamics
Authors: Parra-Santos Teresa , Molina Jordá José M. , Luna-Sandoval Gabriel , Cacho-Perez Mariano , Pérez J. Rubén
Published: December 2016

This work involves the methodology used in the University of Valladolid for Mechanical Engineering students to learn Computational Fluid Dynamics playing an active role. Students pretend to be engineers in a consulting or design office carrying out a fluid mechanics scale down projects. Later they act as reviewers evaluating a project from a colleague. There is a deeper understanding of the topic when they need to discuss the strategies to accomplish the project, to write a technical report and finally to justify the evaluation of other works. Furthermore, they develop their critical thought, writing skills and synthesis capacity. Multimedia material from other institutions that review the concepts learned in the course can be a suitable way to improve the understanding of concepts.
Turbulence Measurements in Pipe Flow With Drag Reducing Polymer Additives
Authors: Pumisacho L. Marylin , Azevedo Luis Fernando A.
Published: December 2016

Pressure drop and instantaneous velocity fields were measured for fully developed turbulent pipe flow of water and a solution of water and long chain polymer at low concentration. Two-dimensional Particle Image Velocimetry technique — PIV, coupled with a particle tracking technique was employed to yield velocity fields with high spatial resolution. Turbulence statistics were obtained from a series of approximately 2500 instantaneous velocity fields measured for each flow configuration characterized by the turbulent Reynolds number and the polymer concentration. Tests were conducted for a turbulent Reynolds number range from Reτ≈1764 to Reτ≈3154, and for 20 wppm of Superfloc A110 polymer in water. Time-averaged, rms velocity fluctuations and turbulent shear stresses profiles were measured. Drag reductions of the order of 50% were measured. Changes in the axial and wall-normal velocity fluctuations were measured and linked to the presence of the polymer. Reynolds stresses were also shown to decrease in the buffer layer of polymer solution flows as a result of a decrease in the correlation of axial and wall normal fluctuations. A deficit of the viscous shear stress and Reynolds stresses in relation to the total stress was measured close to the wall and attributed to the polymer stresses exerted on the fluid. All the results obtained were in agreement with the available literature, which serve to validate the procedures and test section employed in the experiments.
Quantification of Numerical and Modeling Errors in Simulation of Fluid Flow Through a Fixed Particle Bed
Authors: Volk Annette , Ghia Urmila , Stoltz Christopher , Hecht John , Stamper Jason
Published: December 2016

An open-source coupled Computational Fluid Dynamics (CFD) – Discrete Element Method (DEM), CFDEM, is employed to study flow through a fixed particle bed. The simulation is repeated for a range of computational cell sizes, and the solution trend is analyzed. A grid-refinement study procedure, standard for publication of CFD simulation results, is applied to the CFDEM simulations. The results are analyzed, with emphasis on the frequency of convergence and a comparison of the expected numerical error and extrapolated-solution error, termed the ‘offset’ method.

Methods of analysis for numerical modeling parameters, as well as uniform reporting procedures, have not been established for granular-flow simulations. This has led to modeling errors and incorrect results that have hampered fluidization research. The present work shows that the standard grid-refinement study is applicable to granular-fluid flows, and produces results that are useful for common modeling choices such as drag correlation and determination of optimal computational cell size. Additional analysis procedures developed in this study, and based on the grid-refinement results, are shown to give good estimates of the resulting solution error.
Numerical Analysis on Non-Equilibrium Steam Condensing Flow in Rotating Machinery
Authors: Kim Changhyun , Park JaeHyeon , Kim DongIl , Baek Jehyun
Published: December 2016

Flow of steam, different from other gas flows, involves droplet generation in flow expansion process. This phase transition affects not only the flow fields, but also machine performance including efficiency. In addition, it is totally harmful for machine structures as blades and casing. Therefore, prevention or preparation of droplet generation in steam flows is dreadfully important in stable machine operation.

Nowadays, Computational Fluid Dynamics (CFD) is widely used in machine design and optimization process. Thus, simulation with CFD should consider this droplet generation phenomena to predict internal flows precisely. Many studies that analyze steam condensing flow in nozzles, cascades and steam turbines were carried out. Though, the flows of wet-steam which include non-equilibrium phase-transition phenomena are still difficult to predict, especially in the 3D rotating cases as steam turbines. Therefore, more studies are required to get comparable results with experiment.

In this study, non-equilibrium wet-steam model was implemented on T-Flow to simulate realistic non-equilibrium steam condensing flow. In the cases of White cascade, characteristics of wet-steam flow were studied and pressure distributions were compared with experimental results for model validation. To use implemented wet-steam model for calculating flows in rotation, especially in steam turbines, a study of steam condensing flow in single stage steam turbine was conducted. Interaction between the stator and rotor using frozen rotor or mixing plane method in steady calculations were compared in order to find the effects of used interface on flow fields and steam condensation.

As a result, condensing flows were predicted well even in the rotating cases by using non-equilibrium wet-steam model. The wet-steam parameters (nucleation, droplet size, wetness) are differed throughout the spans due to 3D effects and influenced by selection of interface as expected. In addition, droplet generation enhances entropy rise throughout the domain. The case using mixing plane seems to be overestimate the size of high wetness zone and it is recommended to use frozen rotor in multi-phase calculations. However, to apply this model in general cases, comparison with experimental data from real steam turbines should be conducted in further studies.
Application of the Reynolds Stress Model to Direct Modeling and Actuator Disk Simulations of a Small-Scale Horizontal-Axis Wind Turbine
Authors: Jackson Randall , Amano Ryoichi S.
Published: December 2016

Computational Fluid Dynamics (CFD) has become a staple in wind energy research and studies cover a broad range of topics including atmospheric wind profiles, airfoil design, wind turbine design, terrain effects, and wake dynamics. One of the most important aspects of applying CFD methods is the selection of a turbulence closure model when solving the Reynolds Averaged Navier-Stokes (RANS) equations. In this research, the Reynolds Stress Model (RSM) was applied to predict the wake turbulence and velocity profiles for a small scale, 3-bladed, horizontal-axis wind turbine (HAWT) using a commercial CFD software, Star CCM+. The wind turbine was modeled directly by discretizing the rotor and also using an actuator disc concept to simulate the rotor. Wind tunnel experiments were performed using hot-wire anemometry to measure the velocity deficit at various downstream locations. High speed images were also captured to examine qualitatively the wake and tip vortex dissipation created from an oil mist. The CFD results show the RSM turbulence closure model to be excellent in predicting the wake velocity and tip vortex structure when compared to experimental results.
Massively Parallel Curved Spectral/Finite Element Mesh Generation of Industrial CAD Geometries in Two and Three Dimensions
Authors: Ghasemi Arash , Taylor Lafayette K. , Newman James C.
Published: December 2016

A scalable paradigm is developed to generate 2D/3D high quality finite/spectral element meshes containing arbitrarily curved elements. The current methodology begins with a linear mesh that is decomposed using a graph partitioning scheme. Higher-order elements are then created from the linear mesh, where a CAD model must be queried in order for the curved faces/edges to conform to the boundaries. Subsequently, the curved elements are directly generated using analytical maps which transform the point distribution of the master element to the element in physical space. These analytic maps are derived for triangular, quadrilateral, tetrahedral, prismatic, pyramidal, and hexahedral elements. It is shown that the stretching of Chebyshev/Fekete point distributions are also preserved by these maps and hence they can be used to generate well-conditioned spectral element grids. Since these maps require a computationally intensive min-distance projection to the CAD model, a fast min-distance search algorithm is proposed. The current method is embarrassingly parallel, uses MPI, and is implemented on a commodity cluster. Degradation in performance is observed with load balancing based on maximizing the volume to surface ratio and, therefore, a new load balancing is proposed to mitigate this loss in speed-up. Results are presented for a two-dimensional cylinder, NACA0012 airfoil, 30P30N high-lift geometry, a three-dimensional sphere, a notional missile configuration and a civil aircraft geometry.
A Numerical Study of Droplet Impingement for In-Flight Ice Accretion Prediction
Authors: Zhang Hao , Wen Chihyung , Su Junwei
Published: December 2016

Droplet impingement is the basic module in both ice accretion and anti-icing numerical calculation. A three dimensional finite volume approach with the capacity of modeling the in-flight droplet impingement on a wide range of subsonic regime is therefore established in this research, using OpenFOAM®. The Eulerian model is applied to estimate the droplet flow field with the same computational grid sets as those of the air flow calculation. The roughness effect caused by ice accretion is considered in the wall function modeling. Thus, the collection efficiency could be investigated for further icing numerical simulations. This approach is validated on both cylinder and sphere benchmark cases. The results are compared with the corresponding experimental and LEWICE (LEWis ICE accretion program) simulation data.
Simulation of Forward Osmosis Flow in a Two-Dimensional Asymmetric Membrane Channel With Draw Channel Circular Baffle Implementation
Authors: Koch James R. L. , Agarwal Ramesh K.
Published: December 2016

Forward Osmosis (FO) driven asymmetric membrane filtration is a developing technology which shows promise for seawater desalination and wastewater treatment. Due to the fact that asymmetric membranes are widely used in conjunction with this technology, internal concentration polarization (ICP), a flow-entrainment effect occurring within such membranes, is a significant if not dominant source of overall osmotic pressure loss across the membrane. Accurate modeling of ICP effects is therefore very critical for accurate Computational Fluid Dynamic (CFD) modeling of asymmetric membranes. A related, dilutive effect known as external concentration polarization (ECP) also develops on both the rejection and draw sides of the membrane, further contributing to osmotic pressure loss. In order to increase the overall water flux, circular spacers can be implemented within the draw channel of FO cross-flow membrane exchange units to decrease the effects of ICP and draw ECP. The drawback of spacer inclusions is an increased pressure loss across the length of the feed channel. The system efficiency gained by the decrease in ECP must therefore be weighed against the energy cost of hydraulically making up lost channel pressure. To model the geometry of a FO cross-flow channel, the open source CFD package OpenFOAM is used. A compressible flow model with explicit boundary conditions is developed to simulate the flux transfer and ICP effects present within an asymmetric membrane when exposed to a NaCl solution. Results are validated by comparison with the numerical data generated by earlier models of asymmetric membranes implemented by other investigators using similar simulation conditions.
Self-Excited Vibration of a Flat Plate With a Hole for Water Flow
Authors: Takahashi Kosuke , Hiroki Fujio , Sato Kotaro , Nishibe Koichi
Published: December 2016

In fluid machines such as turbo-pumps and hydro-turbines, self-exited vibrations are among the most serious problems that can cause accidents. However, there have been few reports on the self-excited vibrations, which are treated as a coupled problem between the stiffness of the plate and flow disturbance. Basic studies have been performed to clarify the mechanism of the cover-plate vibration induced in the turbo machinery. In the present study, we employ a water tunnel using a test section comprising a flat plate with a hole and pressure chamber that simulates the passage of impeller of the hydraulic machines, and we discuss the characteristics of the self-excited vibration of a flat plate using a hole for water flow. The results show that the vibration occurs when the natural frequency of the plate corresponds approximately with the specific frequency when the Strouhal number St ≈ 0.5, and the frequency of flat-plate vibration depends on the flow velocity. In addition, we show that the amplitude of the vibration is related to the thickness of the plate, geometry of the hole (circle, square), and flow angle for the square hole.
Characteristics of Twin Jets in the Vicinity of a Free Surface
Authors: Rahman M. S. , Nabess E. M. , Tachie M. F.
Published: December 2016

Investigation of turbulent characteristics of twin jet near the free surface was carried out experimentally at four offset height ratios of 1, 2, 3 and 4. The experiments were conducted using square orifice nozzle pair with separation ratio of 2.6 at Reynolds number of 3890. The effect of the free surface as well as the effect of the offset height ratio on the streamwise mean velocity, streamwise turbulence intensity and Reynolds shear stress were discussed. The velocity decay and jet spread were quantified in order to characterize the effect of offset height on entrainment and mixing performance. The flow dynamics at the free surface was characterized by observing the variation of streamwise mean velocity and turbulence intensities at the free surface. Proper orthogonal decomposition was performed and the role of the energetic structures in the surface attaching twin jet was discussed both qualitatively and quantitatively.