bluuebunny/crossref_metadata_2025 huggingface dataset:
Postactivation Potentiation of Horizontal Jump Performance Across Multiple Sets of a Contrast Protocol
Authors: Seitz Laurent B. , Mina Minas A. , Haff G. Gregory
Published: February 2016

Seitz, LB, Mina, MA, and Haff, GG. Postactivation potentiation of horizontal jump performance across multiple sets of a contrast protocol. J Strength Cond Res 30(10): 2733–2740, 2016—This study determined whether a postactivation potentiation (PAP) effect could be elicited across multiple sets of a contrast PAP protocol. Fourteen rugby league players performed a contrast PAP protocol comprising 4 sets of 2 paused box squats accommodated with bands alternated with 2 standing broad jumps. The rest period between the squats and the jumps and between the sets was 90 seconds. A control protocol with standing broad jumps only was performed on a separate session. A standing broad jump was performed ∼2 minutes before each protocol and served as a baseline measurement. Standing broad jump distance was significantly greater (4.0 ± 3.4% to 5.7 ± 4.7%) than baseline during the 4 sets of the contrast PAP protocol with the changes being medium in the first, second, and fourth sets (effect size [ES]: 0.58, 0.67, and 0.69, respectively) and large for the third set (ES: 0.81). Conversely, no PAP effect was observed in the control protocol. Additionally, the stronger players displayed a larger PAP effect during each of the 4 sets of the contrast PAP protocol (Cohen's d: 0.28–1.68) and a larger mean effect across these 4 sets (Cohen's d: 1.29). Horizontal jump performance is potentiated after only 90 seconds of rest after an accommodating exercise, and this PAP effect can be elicited across 4 sets. Additionally, the PAP response is largely mediated by the individual's strength level. These results are of great importance for coaches seeking to incorporate PAP complexes involving horizontal jumps in their training programs.
The Present and Future of Crowdfunding
Authors: Assenova Valentina , Best Jason , Cagney Mike , Ellenoff Douglas , Karas Kate , Moon Jay , Neiss Sherwood , Suber Ron , Sorenson Olav
Published: February 2016

A group of experts discuss their thoughts about the current state of crowdfunding, its future, important emerging trends in the field, and the opportunities and challenges facing investors and entrepreneurs in the space. Across the board, these experts highlight the importance of crowdfunding as a means for mobilizing resources. They also maintain that crowdfunding has already emerged as an important force in global finance, one which appears here to stay, but one where we have only begun to see the ways in which it will transform the financial sector.
What Problems Does Crowdfunding Solve?
Authors: Younkin Peter , Kashkooli Keyvan
Published: February 2016

The expansion of crowdfunding raises two related questions: what type of platform suits each project and how should existing platforms expand? The answer lies in analyzing the field of crowdfunding as a solution to four specific problems: gatekeeping, coordination, inexperience, and patronage. Using an inductive analysis of the largest U.S. sites, this article identifies the range of problems crowdfunding addresses and their performance to date. Crowdfunding succeeds in raising money within and across networks, but efforts to use crowdfunding to educate or to generate recurring revenue are less successful.
Semántica del desnudo cristiano
Authors: Osorio Arango John Jairo
Published: February 2016

Ayudado por las Sagradas Escrituras –fuente primordial–, la Tradición, la
literatura apócrifa, la patrística, la hagiografía, la mística y la leyenda, y otras
herramientas de la historiografía: la biografía de los artistas y lo que las mismas obras de arte revelan, este trabajo busca componer una gramática que sepa leer sin equívocos, confusiones u ofuscasiones el delicado tema de la desnudez en el pensamiento y enfáticamente en la plástica cristiana, sin prescindir del Magisterio de la Iglesia para que esta hermenéutica no se juzgue como mera especulación, y buscando conclusiones no arbitrarias, amañadas o subjetivas. Se trata de un esfuerzo por estructurar la gramática con que el pensamiento cristiano ha visto la representación de la desnudez a lo largo de su bimilenaria tradición y que abre muchísimas y generosas posibilidades de composición y contemplación artística, útiles tanto para la espiritualidad como para la celebración del misterio de Cristo encarnado.
Del corpus theologicum de Xavier Zubiri a una pastoral de la Providencia en Latinoamérica
Authors: Cardona Gómez Adalberto
Published: February 2016

A partir de los tres niveles de la experiencia de Dios en que, según Xavier Zubiri, se concretiza la Providencia divina: a) experiencia universal de religación, propia de todo ser humano; b) experiencia específicamente religiosa (gracia), en las que la iniciativa procede de Dios que se va revelando en el espacio y en el tiempo, a nivel individual, social e histórico; y c) experiencia de la encarnación, constituida por la experiencia de la deiformidad, expresión esencial del cristianismo que se hace realidad en la persona de Cristo, en quien Dios asume forma humana y el hombre se deiformiza, este artículo se acerca a la Providencia por la vía de la encarnación, que le indica al hombre que la experiencia de Dios no lo aleja del mundo sino que lo obliga a él, constatación desde la que se propone
para Latinoamérica una pastoral que integra responsablemente la idea de la Providencia de Dios.
La hermenéutica de Eranos: una exploración de la simbólica del sentido
Authors: Bravo José Luis Luna
Published: February 2016

El presente artículo analiza la estructura de la hermenéutica eranosiana de los símbolos, centrado en las reflexiones de Durand y Campbell, quienes retoman las tesis fundamentales de los padres espirituales de Eranos: Jung y Otto. Además cobran especial valor los estudios que Andrés Ortiz-Osés ha dedicado a Eranos. La tesis propuesta es que la hermenéutica eranosiana se basa en el carácter mediador-redundante del símbolo, de modo que es a través de la fuerza repetitiva de los simbolizantes como se precisa el sentido del simbolizado, siempre inagotable, constituyendo una simbólica redundancia coimplicante. Tras una breve reseña de la historia de Eranos, la tesis planteada se desarrolla en cuatro momentos: 1) descripción del carácter trilateral de la experiencia simbólica; 2) descripción de los tipos de signos: el símbolo como un signo lejano; 3) el carácter “infinitamente abierto” del símbolo: la redundancia como apertura; y 4) la hermenéutica eranosiana como complexio oppositorum.
Inference and Analysis of Population Structure Using Genetic Data and Network Theory
Authors: Greenbaum Gili , Templeton Alan R , Bar-David Shirli
Published: February 2016

Clustering individuals to subpopulations based on genetic data has become commonplace in many genetic studies. Inference about population structure is most often done by applying model-based approaches, aided by visualization using distance-based approaches such as multidimensional scaling. While existing distance-based approaches suffer from a lack of statistical rigor, model-based approaches entail assumptions of prior conditions such as that the subpopulations are at Hardy-Weinberg equilibria. Here we present a distance-based approach for inference about population structure using genetic data by defining population structure using network theory terminology and methods. A network is constructed from a pairwise genetic-similarity matrix of all sampled individuals. The community partition, a partition of a network to dense subgraphs, is equated with population structure, a partition of the population to genetically related groups. Community-detection algorithms are used to partition the network into communities, interpreted as a partition of the population to subpopulations. The statistical significance of the structure can be estimated by using permutation tests to evaluate the significance of the partition’s modularity, a network theory measure indicating the quality of community partitions. To further characterize population structure, a new measure of the strength of association (SA) for an individual to its assigned community is presented. The strength of association distribution (SAD) of the communities is analyzed to provide additional population structure characteristics, such as the relative amount of gene flow experienced by the different subpopulations and identification of hybrid individuals. Human genetic data and simulations are used to demonstrate the applicability of the analyses. The approach presented here provides a novel, computationally efficient model-free method for inference about population structure that does not entail assumption of prior conditions. The method is implemented in the software NetStruct (available at https://giligreenbaum.wordpress.com/software/).
A General Approximation for the Dynamics of Quantitative Traits
Authors: Bod'ová Katarína , Tkačik Gašper , Barton Nicholas H
Published: February 2016

Selection, mutation, and random drift affect the dynamics of allele frequencies and consequently of quantitative traits. While the macroscopic dynamics of quantitative traits can be measured, the underlying allele frequencies are typically unobserved. Can we understand how the macroscopic observables evolve without following these microscopic processes? This problem has been studied previously by analogy with statistical mechanics: the allele frequency distribution at each time point is approximated by the stationary form, which maximizes entropy. We explore the limitations of this method when mutation is small (4Nμ < 1) so that populations are typically close to fixation, and we extend the theory in this regime to account for changes in mutation strength. We consider a single diallelic locus either under directional selection or with overdominance and then generalize to multiple unlinked biallelic loci with unequal effects. We find that the maximum-entropy approximation is remarkably accurate, even when mutation and selection change rapidly.
CASO 18-2015:Meningitis por Haemophilus parainfluenzae con sordera secundaria
Authors: Pastor Quesada Aurora , Brenes Pimentel Adriàn , Sedó Mejía Giovanni
Published: February 2016

Paciente masculino de 88 años con antecedentes de hipertensión arterial e hipotiroidismo con cuadro de meningoencefalitis y bacteremia por Haemophilus parainfluenzae en quien se documenta hipoacusia bilateral como secuela.Se analiza la frecuencia de H. parainfluenzae como germen causante de meningitis e hipoacusia secundaria.
CASO 22-2015:Masculino 54 años con ascitis maligna refractaria: uso del catéter venoso central
Authors: Medina Méndez Andrea
Published: February 2016

Paciente masculino de 54 años vecino de Pérez Zeledón con antecedente de etilismo y tabaquismo y portador de una Hepatitis B y un cistoadenoma de la vía biliar. Asocio una ascitis maligno que requería una paracentesis cada 3-4 días por lo que se le coloco un catéter venoso central fenestrado para el drenaje domiciliar de su ascitis con lo que logro mejorar su calidad de vida.
TEMA 15-2015: Beneficios de la colostomía en la calidad de vida del paciente con lesión medular crónica y ventajas de su realización por vía laparoscópica
Authors: Leitón Chaves Andres , Hu Liang Huxian , Ramírez Valverde Jose Miguel
Published: February 2016

Las investigaciones recientes sugieren que el manejo de los problemas intestinales es una fuente importante de preocupación para los pacientes con lesión medular y puede alterar significativamente la calidad de vida. Los síntomas gastrointestinales más comunes hallados fueron estreñimiento e incontinencia fecal, reportado por 46% y 41%, respectivamente. Distensión abdominal se reportó en un 22% y el dolor gastrointestinal (dolor abdominal, rectal o anal) fue reportado por 33% de los pacientes. No es sorprendente que los síntomas gastrointestinales estén asociados con depresión, ansiedad, y deficiencias significativas en la calidad de vida en una parte significativa de las personas con lesión de médula espinal. Dada la gravedad de estos síntomas, varios autores han argumentado que las opciones quirúrgicas invasivas, incluyendo derivaciones intestinales (colostomía o ileostomía) o la creación de un Enema Anterógrado Continente de Malone (MACE), pueden proporcionar resultados superiores para determinados pacientes con disfunción intestinal neurogénica severa después de la lesión médular. Las ventajas de la colostomía laparoscópica resaltan, particularmente, la posibilidad de evitar una laparotomía amplia con todos sus riesgos. Algunos autores reportan menor formación de adherencias después de la laparoscopia lo que reduce riesgo de obstrucción y facilita la reconstrucción del tránsito en las colostomías temporales. La ventaja indiscutible es el acceso miniinvasivo a los pacientes.
THE EFFECT OF UV-A SUPPLEMENTAL LIGHTING ON ANTIOXIDANT PROPERTIES OF OCIMUM BASILICUM L. MICROGREENS IN GREENHOUSE
Authors: VAŠTAKAITĖ Viktorija , VIRŠILĖ Akvilė , BRAZAITYTĖ, Aušra , SAMUOLIENĖ Giedrė , JANKAUSKIENĖ Julė , SIRTAUTAS Ramūnas , DUCHOVSKIS Pavelas
Published: February 2016

The effects of supplemental UV-A LED lighting on growth and antioxidant properties of two varieties of basil (Ocimum basilicum L.) microgreens were determined. Purple-leaf ‘Dark Opal’ and green-leaf ‘Sweet Genovese’ basils were grown in greenhouse (14 days, 22/18 ± 2 °C day/night temperature, 40 ± 5 % a relative air humidity) during winter season. The main lighting system (HPS lamps and natural daylight) was supplemented with ~13.0 μmol m-2 s-1 flux of UV-A 390 nm, and a total PPFD was ~125 μmol m-2 s-1 (16 h photoperiod) for 1 or 7 days before harvest, or entire growth period – 14 days. The results revealed that the influence of UV-A on growth and antioxidant properties depended on basil variety and duration of irradiation. Generally, UV-A irradiation for 7 days significantly (P ≤ 0.05) inhibited growth and hypocotyl elongation of green-leaf basils, and for 14 days of both basil varieties. No significant differences on leaf chlorophyll index were determined. However, leaf flavonol index significantly increased in green-leaf basils after 7 and 14 days UV-A irradiation. The total phenols ant anthocyanin contents significantly decreased after 1 day UV-A irradiation in purple-leaf basils, and the continuous decrease following UV-A irradiation for 7 or 14 days was determined. In addition, UV-A irradiation had negative effects on ABTS radical activity in purple-leaf basils; however, the significantly higher ABTS radical scavenging activity after UV-A irradiation for 1 or 7 days in green-leaf basils were determined. UV-A influenced higher ascorbic acid synthesis in purple-leaf basils after 7 days irradiation, or after 14 days irradiation in both basil varieties. In summary, the supplemental UV-A LED lighting allows to protect basil microgreens from hypocotyl elongation, and enhances antioxidant properties in green-leaf basils. Purple-leaf basils showed to be more sensitive to UV-A irradiation, and less positive effects on antioxidant properties were determined.
GRAFICBOMB: SOFTWARE PARA CÁLCULOS HIDRÁULICOS E CUSTOS DE BOMBEAMENTO
Authors: Loureiro Gláucio Ferreira , Carvalho Jacinto De Assunção
Published: February 2016

GRAFICBOMB: SOFTWARE PARA CÁLCULOS HIDRÁULICOS E CUSTOS DE BOMBEAMENTO1  GLÁUCIO FERREIRA LOUREIRO 2 E JACINTO DE ASSUNÇÃO CARVALHO3 1 Parte da dissertação de mestrado do primeiro autor; 2 Prof. Substituto do Departamento de Ciência da Computação e Doutorando do Programa de Pós Graduação em Recursos Hídricos em Sistemas Agrícolas da UFLA, (Campus Universitário, Caixa Postal 3037 CEP 37200-000 Lavras-MG), email: glaucio_ufla@yahoo.com.br; 3 Professor Associado do Departamento de Engenharia da UFLA, (Campus Universitário, Caixa Postal 3037 CEP 37200-000 Lavras-MG), email: jacintoc@deg.ufla.br;        1 RESUMO A determinação do custo de bombeamento é de extrema importância, tendo em vista que o mesmo representa uma parcela significativa dos custos totais de irrigação. Contudo a determinação deste custo, às vezes, se torna trabalhosa devido à necessidade de escolha do sistema tarifário mais vantajoso através do cálculo do ponto de operação e a adequação deste ponto ao ponto de projeto. Em função disso, se desenvolveu um software por meio da IDE Visual Studio 2010© e em linguagem VB.NET para geração das curvas da bomba e do sistema e cálculo do ponto de operação, além da adequação do ponto de projeto visando obter o custo de bombeamento de acordo com a tarifação escolhida pelo projetista. O software apresenta uma interface amigável, bem como fornece resultados confiáveis, podendo se tornar uma importante ferramenta no auxílio à tomada de decisão de projetos hidráulicos. Palavras-chave: Hidráulica, ponto de operação, tarifação de energia  LOUREIRO, G.F; CARVALHO, J.A. GRAFICBOMB: SOFTWARE FOR HYDRAULIC AND PUMPING COST   CALCULATIONS    2 ABSTRACT Determining cost of pumping is of utmost importance, as it represents a significant portion of the total cost of irrigation. However, cost determination, sometimes becomes laborious because of the need to choose the most advantageous   tariff system through the calculation of the operating point and adequacy of this point to the project point. So, a software was developed through the IDE Visual Studio 2010©  and VB.Net language for generation of the  pump and system  curves and calculation of the operating point to suit the project point,  aiming at  the cost of pumping  according to the tariff of energy chosen by the projectionist.   The software provided reliable results with a friendly interface, and it may become an important tool to support   the decision-making process concerning hydraulic projects. Keywords: hydraulics, operating point, energy tariff
Numerical modelling of submarine landslides with sensitive clay layers
Authors: Dey R. , Hawlader B. C. , Phillips R. , Soga K.
Published: February 2016

A large-deformation finite-element (FE) modelling technique is presented to model submarine landslides. A strain softening model for undrained shear strength of marine clay is incorporated in the FE modelling. The development of large plastic shear strain concentrated zones (shear bands) and their propagation with displacement of soil mass are simulated. FE simulations show that the existence of a weak layer might result in the initiation and propagation of shear bands leading to large-scale progressive landslides. Such progressive development of failure planes cannot be simulated using the limit equilibrium method of slope stability analysis. Depending upon the geometry and soil properties, a number of failure patterns are identified which are comparable with morphologic features seen in field observations. Based on this type of FE analysis and compared with seabed morphology, the developed failure planes could be identified where the shear strengths are expected to be lower because of pre-shearing than the shear strengths of the soil outside these zones, which could then be implemented in the modelling of seabed for offshore development projects in the areas where failure occurred in the past.
Absorption of volatile organic compounds by different wool types
Authors: Mansour Elie , Curling Simon , Stéphan Antoine , Ormondroyd Graham
Published: February 2016

This paper summarises the quantitative analysis of the absorption of volatile organic compounds (VOCs), namely gaseous formaldehyde, toluene, limonene and dodecane, by different wool types. VOCs are of increasing concern due to their role as accumulating indoor air contaminants, and this paper demonstrates the potential of wool as a sustainable and natural solution to this problem. Building on previous data, different wool types were tested by way of two different methods to assess their absorption ability with regard to these VOCs. For formaldehyde analysis, the samples were subjected to cycles of exposure to excess formaldehyde gas while the weight gain was measured. For the other VOCs, a modified microchamber was used to flow the gases through the samples, followed by trapping and quantification of the non-absorbed VOCs using Tenax TA tubes. The data presented indicate that wool is able to absorb a range of VOCs in differing amounts. The data also show that the amount and the type of VOCs absorbed by wool were dependent on the sheep breed and the processing of the wool.
The MX beamlines BL14.1-3 at BESSY II
Authors: Gerlach Martin , Mueller Uwe , Weiss Manfred S.
Published: February 2016

The Macromolecular Crystallography (MX) group at the Helmholtz-Zentrum Berlin (HZB) is operating three state-of-the-art synchrotron beamlines for MX at BESSY II in Berlin (Heinemann et al., 2003; Mueller et al., 2012, 2015). The radiation source for all three beamlines BL14.1-3 is a superconducting 7T-wavelength shifter. Currently, the three beam lines are the most productive stations for MX in Germany, with about 250 PDB depositions per year and over 1500 PDB depositions in total (Status 10/2015). BL14.1 and BL14.2 are energy tuneable in the range 5.5-15.5 keV, while beam line BL14.3 is a fixed-energy side station operated at 13.8 keV. The HZB-MX beamlines are in regular user operation providing close to 200 beam days per year and about 600 user shifts to approximately 100 research groups across Europe. Additional user facilities include office space adjacent to the beam lines, a sample preparation laboratory, a biology laboratory (safety level 1) and high-end computing resources.
The choice of treatment for macular edema following retinal vein occlusion
Authors: Moshetova Larisa Konstantinovna , Tsikhonchuk Tat'yana Vyacheslavovna , Turkina Kseniya Ivanovna , Ignat'ev Sergey Aleksandrovich
Published: February 2016

A clinical efficacy assessment was performed for the therapy of post-occlusive cystoid macular edema using intravitreal anti-VEGF-ranibizumab injections at short and remote terms from the disease onset. It has been shown that ranibizumab intravitreal injections in retinal vein occlusion allow to increase visual acuity and to reduce retinal edema, and thus rehabilitate patients in maximally short terms. Intravitreal injections of vascular endothelial growth factor inhibitors at short terms from the disease onset allow achieving stabilization of the pathological process with preservation or improvement of visual functions, while reducing the number of repeated intravitreal injections.
A case of cosmetic rehabilitation after eyeball destruction (case report)
Authors: Pysin Alexey Yurievich , Kulikov Alexey Nikolaevich , Sosnovskiy Sergey Viktorovich , Shamrey Denis Vladislavovich
Published: February 2016

This case report describes a successful cosmetic rehabilitation of a patient after very severe open globe injury (received by an oscillating saw). At primary surgical procedure (PSP), an eyeball destruction was diagnosed, and therefore, PSP has been completed with evisceration. To optimal cosmetic rehabilitation of patient, silicone oil-filled (silicon oil viscosity - 1300 cSt) mobile stump was created. No postoperative infectious complications were observed. Successful cosmetic rehabilitation (aesthetic factor was 82.6 %) was achieved after the selection of individual thin-walled ocular prosthesis. Evisceration followed by creation of silicon-filled stump at PSP provides successful cosmetic rehabilitation indices after eyeball destruction.
Two aspects of one problem (results of questionnaire analysis in glaucoma patients)
Authors: Podyninogina Valentina Vladimirovna , Bagaev Vladimir Ivanovich , Chuprov Alexandr Dmitrievich
Published: February 2016

The purpose of the study was to investigate the compliance of ophthalmologists and glaucoma patients using questionnaires for patients. Materials and methods: Questionnaires were applied to 72 glaucoma patients. The age range was between 47 and 76 years. All the patients were asked to answer anonymously a number of questions about their disease and treatment. Results and discussion: Problems of interaction and mutual understanding of ophthalmologists and glaucoma patients were revealed. On the one hand, ophthalmologists do not clearly and precisely explain to patients the importance of monitoring and treatment for glaucoma being a chronic disease. On the other hand, patients demonstrate carelessness regarding their health. Conclusion: Our goal was to help glaucoma patients to completely realize their problems, to incline them for treatment and to persuade them that they can cope with their problems only by cooperation of ophthalmologists and patients.
Maintained Stemness of Human Periodontal Ligament Stem Cells Isolated After Prolonged Storage of Extracted Teeth
Authors: Kim Kihyun , Yi TacGhee , Yun Jeong‐Ho
Published: February 2016

Background: Human periodontal ligament stem cells (hPDLSCs) are readily accessible and represent a promising source of mesenchymal stem cells (MSCs) for therapies. For expected clinical applications of stem cell therapies, prolonged maintenance of stemness of hPDLSCs after storage is crucial. Likewise, optimization of cell quality and standardization of manufacturing protocols require evaluation of hPDLSC characteristics after storage. The aim of this study is to evaluate maintenance of stemness of hPDLSCs isolated after prolonged storage of the periodontal ligament (PDL), by studying: 1) growth and proliferation; 2) immunophenotypes; and 3) differentiation capabilities of hPDLSCs.

Methods: After extraction of premolars (N = 10), hPDLSCs were isolated immediately (n = 5) or after 1 week of tooth storage in growth medium (n = 5). Both groups were evaluated for: 1) colony formation; 2) proliferation; and 3) immunophenotypes. Osteogenic, adipogenic, and chondrogenic differentiation capabilities of hPDLSCs were evaluated at different times and by real‐time polymerase chain reaction (PCR).

Results: Storing PDLs attached to teeth did not affect stemness of hPDLSCs. Colony formation and proliferation properties of hPDLSCs from PDLs harvested immediately after extraction or after storage for 1 week were comparable, and there were no significant differences in immunophenotypic markers between the two groups. Osteogenic, adipogenic, and chondrogenic differentiation capabilities of hPDLSCs were unaltered after PDL storage. Real‐time PCR analyses indicated that the expression of: 1) osteogenic (runt‐related transcription factor 2, alkaline phosphatase, and osteocalcin); 2) adipogenic (peroxisome proliferator‐activated receptor‐γ and lipoprotein lipase); and 3) chondrogenic (aggrecan, collagen Type 2, and collagen Type 10) differentiation markers were similar for both groups.

Conclusion: Within the limitations of the study, hPDLSCs stored for 1 week maintain the important characteristics of MSCs.
Enseñanza de la Historia y enfoque narrativo
Authors: Cuesta Virginia
Published: February 2016

Siguiendo a Jerome Bruner (2003), podemos sostener que nuestro modo de pensar el mundo es narrativo, desde muy temprana edad frecuentamos relatos y también los producimos, estos nos brindan una serie de conocimientos para orientarnos en nuestra sociedad. Asumir esta mirada narrativa, transitada hace décadas pero nunca totalmente instalada en la enseñanza de la Historia, nos permite generar prácticas de aprendizaje significativas que interpelen a los estudiantes además de articular con discursos, literarios, cinematográficos, televisivos, de amplia circulación y potencia. De este modo, el presente artículo tiene como fin, revisitar y dar a conocer mi investigación y propuesta de trabajo para la enseñanza de la historia en el nivel secundario desde un enfoque narrativo.
Increasing Benzodiazepine Prescriptions and Overdose Mortality in the United States, 1996–2013
Authors: Bachhuber Marcus A. , Hennessy Sean , Cunningham Chinazo O. , Starrels Joanna L.
Published: February 2016

Objectives. To describe trends in benzodiazepine prescriptions and overdose mortality involving benzodiazepines among US adults.

Methods. We examined data from the Medical Expenditure Panel Survey and multiple-cause-of-death data from the Centers for Disease Control and Prevention.

Results. Between 1996 and 2013, the percentage of adults filling a benzodiazepine prescription increased from 4.1% (95% confidence interval [CI] = 3.8%, 4.5%) to 5.6% (95% CI = 5.2%, 6.1%), with an annual percent change of 2.5% (95% CI = 2.1%, 3.0%). The quantity of benzodiazepines filled increased from 1.1 (95% CI = 0.9, 1.2) to 3.6 (95% CI = 3.0, 4.2) kilogram lorazepam equivalents per 100 000 adults (annual percent change = 9.0%; 95% CI = 7.6%, 10.3%). The overdose death rate increased from 0.58 (95% CI = 0.55, 0.62) to 3.07 (95% CI = 2.99, 3.14) per 100 000 adults, with a plateau seen after 2010.

Conclusions. Benzodiazepine prescriptions and overdose mortality have increased considerably. Fatal overdoses involving benzodiazepines have plateaued overall; however, no evidence of decreases was found in any group. Interventions to reduce the use of benzodiazepines or improve their safety are needed.
Comments: Macondo 5 Years Later
Authors: Donnelly John
Published: February 2016

Editor's column

The Macondo explosion and oil spill occurred 5 years ago this month, freezing activity in the US Gulf of Mexico and putting the industry in a negative spotlight for weeks. But, in addition to drawn-out legal consequences, the accident spawned new technology, improved safety practices, and better operations awareness. Some of the improvements are still a work in progress.

On 20 April 2010, a blowout and explosion on the Deepwater Horizon rig on the Macondo prospect in the deepwater US Gulf of Mexico killed 11 crewmen. On 22 April, the rig sank, leaving the well gushing and causing the largest oil spill in US waters. The spill continued until 15 July when it was finally capped, and relief wells permanently sealed the well.

Five years later, the impact of the disaster is clearer. Despite fears from some in the oil and gas industry, the accident and resulting regulation did not greatly harm US offshore oil output. The government temporarily stopped drilling in the US Gulf but operators were able to obtain new drilling permits within a year. Now, several large new oil projects are on the horizon, including ones by Shell, ExxonMobil, Hess, and Chevron. The new projects, with a potential to produce close to 1 million B/D, promise to return the Gulf into a major source of US production, although the greatest threat now is not regulation stemming from the oil spill but from the recent steep drop in oil prices. In 2001, the Gulf of Mexico accounted for a fourth of US oil output, but production has dropped since then because of well decline and the drop in permits issued after Macondo. With the recent dramatic rise in onshore unconventional output in the US, the Gulf now accounts for only about 10% of US oil production.

But Macondo did hurt the industry’s reputation—the oil spill dominated news headlines for weeks. The recent concern about the safety of hydraulic fracturing operations and crude oil transport by pipeline or railcar stem in part from the fallout of the Macondo disaster. All of this plays into the industry’s “license to operate” in communities around the globe. Any dramatic, high news impact industry incident— upstream or downstream—heightens public awareness about industry operations and their potential impact.

The industry has, in fact, improved operations since Macondo: new technologies have been developed to prevent and arrest blowouts and spills, and the industry has improved engagement with the public. The Macondo incident has also transformed risk management in offshore operations, although there is still work to be done, according to DNV GL. The consultancy maintains that there are still lessons to be learned from Macondo; for one thing, companies are tempted to skirt long-term management of risk for shorter-term decisions about profitability. The worry is that sharply lower oil prices will lead to cost cutting and neglecting safety ideas, which will make the industry even more vulnerable when the next Macondo comes around. JPT
Dual-Drillpipe Method Shows Success in PMCD Wells With Cuttings Return
Authors: Aleksandersen Jostein , Vestavik Ola M.
Published: February 2016

Technology Update

The Reelwell Drilling Method (RDM) is a new technology developed to solve certain drilling problems and improve the operation margin for various applications.

The technology uses a specially designed dual drillpipe (DDP), shown in Fig. 1, that has two flow channels, one for the flow of drilling fluid into the well down to the bit and the other for the return flow of fluid from the bottom of the well back to the surface.

Developed in Norway, the RDM has been field tested at various locations in the past several years. The technology has features for pressurized mud cap drilling (PMCD), managed pressure drilling (MPD), and extended reach drilling (ERD). The RDM enables

PMCD with cuttings return

MPD with a constant well pressure profile

ERD with reduced torque and drag, no equivalent circulating density (ECD) in the wellbore, and no cuttings in the hole

The DDP is available in 6?-in. steel and 5?-in. to 7½-in. aluminum pipe diameters. With a pressure rating of 5,000 psi, the DDP contains a concentric inner pipe with a stab-in connector and is handled in the same way as a conventional drillpipe.

The RDM can be adapted to a standard drilling rig, with the following tools and arrangements:

A top drive adapter—a swivel directing the fluid return through a second standpipe and mud hose

An inner pipe valve—a bottomhole assembly (BHA) tool for the isolation of the drillstring during connections

A flow control unit—a skid with a control valve system for flow and pressure control

A rotary control device—a standard tool at the blowout preventer for MPD The RDM uses standard BHA components and drill bits, and the tools operate on reduced flow rates.
Evolution of Multistage-Fracture Completions in a North Sea Environment
Authors: Carpenter Chris
Published: February 2016

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 170641, “The Evolution, Optimization, and Experience of Multistage- Fracturing Completions in a North Sea Environment,” by T.R. Koløy, K. Brække, T. Sørheim, and P. Lønning, Trican, prepared for the 2014 SPE Annual Technical Conference and Exhibition, Amsterdam, 27–29 October. The paper has not been peer reviewed.

This paper reviews two newly developed novel completion systems that significantly reduce time spent performing multistage stimulation in environments where cost and consequence of failure are high. Both coiled-tubing and wireline-manipulated sliding-sleeve/valve systems and balldrop-actuated systems have been developed and deployed, depending on the various completion and stimulation challenges faced. Since their first installation in 2009, these systems have been proven and refined in multiple wells for two major operators.

Background

For many of the fields requiring stimulation in the North Sea, cemented plug-and- perforation (plug-and-perf) completions have been used historically. It is a flexible solution in terms of the various types of stimulation designs that can be accommodated. However, because of the large number of perforating runs required, the bridge-plug setting, the retrieving or milling involved, and the clean out runs required, it is also a very time-consuming option. The turnaround times per stage have been widely documented and often range from 3 to 7 days.

Prototype Development, Testing, and Qualification. Sliding sleeves have been used for flow-control purposes in oil and gas wells for decades. Although sliding sleeves are simple in design, many users have questioned their reliability, and they did not see much use for fracturing operations until the mid-2000s, when ball-drop-actuated sliding sleeves entered the market. The preferred method for stimulating a reservoir with a cemented liner—stage by stage—has been with plug-and-perf methods. Plug-and-perf provides a proven method of initial stimulation, compartment for compartment, but provides no solution for efficient production management over the life of the well.
Development of a Stranded Tight Gas Field in the North Sea With Hydraulic Fracturing
Authors: Carpenter Chris
Published: February 2016

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 170852, “Development of a Stranded Tight Gas Field in the UK Southern North Sea With Hydraulic Fracturing Within a Subsea Horizontal Well: A Case Study,” by Marc Langford, SPE, Douglas Westera, SPE, and Brian Holland, SPE, Centrica Energy, and Bogdan Bocaneala, SPE, and Mark Norris, SPE, Schlumberger, prepared for the 2014 SPE Annual Technical Conference and Exhibition, Amsterdam, 27–29 October. The paper has not been peer reviewed.

There are more than 100 accumulations in the southern North Sea that are flagged as stranded fields. One of these stranded tight gas fields, the Kew field, has been developed successfully with the use of a subsea well, horizontal drilling, and hydraulic fracturing. Because this was a subsea development well, all the hydraulic-fracturing operations had to be performed with the rig in place. The utmost efficiency of the operations was paramount; otherwise, the economics of the project would be affected negatively.

Well Overview

The Kew field is a gas field, with small volumes of associated condensate, located in Blocks 49/4a, 49/5a, 49/5b, and 49/4c of the UK continental shelf. It lies 120 km east of the English coast and 5 km west of the UK/Netherlands median line. The field location is pictured in Fig. 1. (For further geological and geophysical details of the Kew field, please see the complete paper.)

The planned Kew 49/04c-7Y subhorizontal development well was drilled along the crest of the Kew structure and is a sidetrack of the existing (suspended) Kew appraisal well 49/4c-7z.

The planned sidetrack 49/04c-7Y was initially intended to target the Lower Carboniferous units. To maximize reservoir contact, the well was initially planned to be completed with four to five hydraulic fractures, with a minimum of one per target unit. Because of the proximity to the gas/water contact, the decision was made to complete the well with a cased-and-cemented liner and plug-and-perforation technique for placement and isolation of the hydraulic fractures. Previous experiences with openhole uncemented multistage systems have positively affected the efficiency of hydraulic-fracturing execution in the North Sea. Also, previous experience of spalling and out-of-gauge hole was another driver toward a cemented system.
Cluster Liquefied Natural Gas: A New Paradigm for Small- and Medium-Scale LNG Business
Authors: Carpenter Chris
Published: February 2016

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 171510, “Cluster Liquefied Natural Gas: New Paradigm for Small and Medium Liquefied-Natural-Gas Business,” by JungHan Lee, LNG Solutions, prepared for the 2014 SPE Asia Pacific Oil and Gas Conference and Exhibition, Adelaide, Australia, 14–16 October. The paper has not been peer reviewed.

Small- and medium-scale liquefied natural gas (LNG) is different from conventional LNG in trading distances, target markets, and application areas. Small- and medium-scale LNG may better coordinate needs between regional gas producers and consumers. Cluster LNG is a new concept of LNG technology suitable for emerging market environments. High performance of cluster LNG originates from higher liquefaction temperature and the adoption of efficient refrigerants for the temperature ranges. The inherent high performance of cluster LNG enables low capital expenditure (CAPEX) and low operational expenditure (OPEX).

Background

Small-scale LNG has so far constituted only a minor portion of global LNG production. However, there are many necessities of regional energy infrastructures and technologies that are different from those of traditional LNG. In Southeast Asian countries, natural gas and LNG sometimes compete with diesel oil rather than large-scale pipeline gas or large-scale LNG. At the same time, there are many small scattered gas sources remaining to be monetized for domestic markets in the region. Nevertheless, these domestic gas fields have not been developed properly so far because of small units of production and, as a result, high cost per unit. In this regard, new technologies suitable for small- and medium-scale LNG development may be necessary.

LNG for global exports and LNG intended for regional demands may need different approaches. Typical large-scale LNG aims to export at a radius up to 10 000 km; on the other hand, small- and medium-scale LNG may need only a 500- to 2 000-km radius.
Purification of Natural Gas by Use of Carbon-Molecular-Sieve Membranes
Authors: Carpenter Chris
Published: February 2016

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 172085, “Purification of Natural Gases by Use of Carbon-Molecular-Sieve Membranes,” by Subrata Mondal and Kean Wang, The Petroleum Institute, Abu Dhabi, prepared for the 2014 SPE Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 10–13 November. The paper has not been peer reviewed.

Carbon-molecular-sieve membranes (CMSMs) are a promising candidate for natural-gas purification because of their excellent stability, permeation selectivity, and permeability. In this project, two CMSM samples were synthesized at different pyrolytic conditions and examined for separation of N2/CH4 gas pairs. Analysis revealed that both surface diffusion and molecular sieving play important roles in gas-permeation mechanisms, which results in abnormal behaviors in the selectivities of different gas molecules.

Introduction

Because of its abundance in natural reservoirs and relatively clean-burning nature, natural gas (NG) (CH4>70%) is becoming increasingly important to the global energy supply. Raw NG contains such impurities as carbon dioxide (CO2), hydrogen sulfide (H2S), H2O, and N2, which can result in health hazards, corrosion of equipment, and lower heating value. The concentration of these impurities varies considerably in NGs produced at different locations but should be reduced to certain levels before shipment.

Currently, large-scale NG- processing plants employ such technologies as adsorption (e.g., dehydration), absorption (e.g., amine wash for the removal of H2S and CO2), and cryogenic distillation (e.g., N2 removal). Although these technologies are mature and effective, they are expensive, energy-intensive, and environmentally unfriendly. For example, an N2- removal unit (NRU) generally operates at temperatures lower than –150°C, while the amine-wash unit requires constant maintenance and solvent replenishing.

Membrane technology offers great advantages for NG processing. It is compact, easy to install or scale up, and requires minimal space, energy input, labor, and maintenance resources. These attributes make it particularly attractive for offshore and remote gas fields. Currently, membrane modules for CO2 removal are commercially available and are the dominant technology in offshore applications even as they become more important in onshore applications. However, improvements are needed to compete with the current technologies in large-scale, inland NG-processing plants.
Design Methods for Subsea Equipment for Extreme and Survival Load Conditions
Authors: Carpenter Chris
Published: February 2016

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 25352, “Design Method and Load- and Resistance-Factor Design for High-Pressure/High-Temperature Subsea Equipment for Extreme and Survival Load Conditions,” by Parth D. Pathak and Samuel L. Taylor, OneSubsea, prepared for the 2014 Offshore Technology Conference, Houston, 5–8 May. The paper has not been peer reviewed.

This paper posits a design method for subsea equipment governed by American Petroleum Institute (API) Specification (spec.) 17 (and particularly 17D). Fatigue-life estimation is also addressed for these conditions. An analysis of a subsea-tree component is reviewed, evaluating its combined load capacity for normal, extreme, and survival conditions. Additionally, the fatigue life-cycle estimation for this component is included.

Introduction

The API spec. 17D and spec. 6A provisions have been the governing terms for subsea trees and wellheads, providing the design guidelines for normal operating conditions up to 15,000 psi. The recently published API Technical Report (TR) 1PER15K-1 and TR 17TR8, the latter still under development, address the design methodology for normal operating high-pressure/ high-temperature (HP/HT) conditions. But these specifications and technical reports do not provide design guidelines for extreme and survival operating conditions. This paper tries to address design methods for subsea equipment that falls under API spec. 17, with focus on subsea trees and wellheads for such conditions.

API Recommended Practice (RP) 17G, which is intended for design of completion and workover risers, addresses these extreme and survival load operating conditions. It provides the equipment’s normal, extreme, and survival operating capacities on the basis of safety factors applied to the ultimate capacity. It also provides allowables based on yield strength with condition factors for extreme and survival conditions. This paper provides a methodology whereby the design factors for the extreme and survival load conditions from API RP 17G are adapted so that they can be applied to API spec. 17D equipment. Because testing the API spec. 17D equipment to its ultimate capacity is not easily feasible, an elastic/plastic analysis method based on American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII, Division 2 or Division 3 (ASME Division 2 or 3) is suggested to determine the ultimate capacity of the equipment.