bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural Heterogeneities Determine Response Characteristics to Second-, but Not First-Order Stimulus Features
Authors: Metzen Michael G. , Chacron Maurice J.
Published: February 2015

Neural heterogeneities are seen ubiquitously, but how they determine neural response properties remains unclear. Here we show that heterogeneities can either strongly, or not at all, influence neural responses to a given stimulus feature. Specifically, we recorded from peripheral electroreceptor neurons, which display strong heterogeneities in their resting discharge activity, in response to naturalistic stimuli consisting of a fast time-varying waveform (i.e., first-order) whose amplitude (i.e., second-order or envelope) varied slowly in the weakly electric fishApteronotus leptorhynchus. Although electroreceptors displayed relatively homogeneous responses to first-order stimulus features, further analysis revealed two subpopulations with similar sensitivities that were excited or inhibited by increases in the envelope, respectively, for stimuli whose frequency content spanned the natural range. We further found that a linear–nonlinear cascade model incorporating the known linear response characteristics to first-order features and a static nonlinearity accurately reproduced experimentally observed responses to both first- and second-order features for all stimuli tested. Importantly, this model correctly predicted that the response magnitude is independent of either the stimulus waveform's or the envelope's frequency content. Further analysis of our model led to the surprising prediction that the mean discharge activity can be used to determine whether a given neuron is excited or inhibited by increases in the envelope. This prediction was validated by our experimental data. Thus, our results provide key insight as to how neural heterogeneities can determine response characteristics to some, but not other, behaviorally relevant stimulus features.
Valproate-Induced Neurodevelopmental Deficits inXenopus laevisTadpoles
Authors: James Eric J. , Gu Jenny , Ramirez-Vizcarrondo Carolina M. , Hasan Mashfiq , Truszkowski Torrey L.S. , Tan Yuqi , Oupravanh Phouangmaly M. , Khakhalin Arseny S. , Aizenman Carlos D.
Published: February 2015

Autism spectrum disorder (ASD) is increasingly thought to result from low-level deficits in synaptic development and neural circuit formation that cascade into more complex cognitive symptoms. However, the link between synaptic dysfunction and behavior is not well understood. By comparing the effects of abnormal circuit formation and behavioral outcomes across different species, it should be possible to pinpoint the conserved fundamental processes that result in disease. Here we use a novel model for neurodevelopmental disorders in which we exposeXenopus laevistadpoles to valproic acid (VPA) during a critical time point in brain development at which neurogenesis and neural circuit formation required for sensory processing are occurring. VPA is a commonly prescribed antiepileptic drug with known teratogenic effects.In uteroexposure to VPA in humans or rodents results in a higher incidence of ASD or ASD-like behavior later in life. We find that tadpoles exposed to VPA have abnormal sensorimotor and schooling behavior that is accompanied by hyperconnected neural networks in the optic tectum, increased excitatory and inhibitory synaptic drive, elevated levels of spontaneous synaptic activity, and decreased neuronal intrinsic excitability. Consistent with these findings, VPA-treated tadpoles also have increased seizure susceptibility and decreased acoustic startle habituation. These findings indicate that the effects of VPA are remarkably conserved across vertebrate species and that changes in neural circuitry resulting from abnormal developmental pruning can cascade into higher-level behavioral deficits.
New Whole-Body Sensory-Motor Gradients Revealed Using Phase-Locked Analysis and Verified Using Multivoxel Pattern Analysis and Functional Connectivity
Authors: Zeharia Noa , Hertz Uri , Flash Tamar , Amedi Amir
Published: February 2015

Topographic organization is one of the main principles of organization in the human brain. Specifically, whole-brain topographic mapping using spectral analysis is responsible for one of the greatest advances in vision research. Thus, it is intriguing that although topography is a key feature also in the motor system, whole-body somatosensory-motor mapping using spectral analysis has not been conducted in humans outside M1/SMA. Here, using this method, we were able to map a homunculus in the globus pallidus, a key target area for deep brain stimulation, which has not been mapped noninvasively or in healthy subjects. The analysis clarifies contradictory and partial results regarding somatotopy in the caudal-cingulate zone and rostral-cingulate zone in the medial wall and in the putamen. Most of the results were confirmed at the single-subject level and were found to be compatible with results from animal studies. Using multivoxel pattern analysis, we could predict movements of individual body parts in these homunculi, thus confirming that they contain somatotopic information. Using functional connectivity, we demonstrate interhemispheric functional somatotopic connectivity of these homunculi, such that the somatotopy in one hemisphere could have been found given the connectivity pattern of the corresponding regions of interest in the other hemisphere. When inspecting the somatotopic and nonsomatotopic connectivity patterns, a similarity index indicated that the pattern of connected and nonconnected regions of interest across different homunculi is similar for different body parts and hemispheres. The results show that topographical gradients are even more widespread than previously assumed in the somatosensory-motor system. Spectral analysis can thus potentially serve as a gold standard for defining somatosensory-motor system areas for basic research and clinical applications.
The 16p11.2 Deletion Mouse Model of Autism Exhibits Altered Cortical Progenitor Proliferation and Brain Cytoarchitecture Linked to the ERK MAPK Pathway
Authors: Pucilowska Joanna , Vithayathil Joseph , Tavares Emmanuel J. , Kelly Caitlin , Karlo J. Colleen , Landreth Gary E.
Published: February 2015

Autism spectrum disorders are complex, highly heritable neurodevelopmental disorders affecting ∼1 in 100 children. Copy number variations of human chromosomal region 16p11.2 are genetically linked to 1% of autism-related disorders. This interval contains theMAPK3gene, which encodes the MAP kinase, ERK1. Mutations in upstream elements regulating the ERK pathway are genetically linked to autism and other disorders of cognition including the neuro-cardio-facial cutaneous syndromes and copy number variations. We report that a murine model of human16p11.2deletion exhibits a reduction in brain size and perturbations in cortical cytoarchitecture. We observed enhanced progenitor proliferation and premature cell cycle exit, which are a consequence of altered levels of downstream ERK effectors cyclin D1 and p27Kip1during mid-neurogenesis. The increased progenitor proliferation and cell cycle withdrawal resulted in premature depletion of progenitor pools, altering the number and frequency of neurons ultimately populating cortical lamina. Specifically, we found a reduced number of upper layer pyramidal neurons and an increase in layer VI corticothalamic projection neurons, reflecting the altered cortical progenitor proliferation dynamics in these mice. Importantly, we observed a paradoxical increase in ERK signaling in mid-neurogenesis in the16p11.2delmice, which is coincident with the development of aberrant cortical cytoarchitecture. The16p11.2delmice exhibit anxiety-like behaviors and impaired memory. Our findings provide evidence of ERK dysregulation, developmental abnormalities in neurogenesis, and behavioral impairment associated with the16p11.2chromosomal deletion.
Targeting the androgen receptor in prostate and breast cancer: several new agents in development
Authors: Proverbs-Singh Tracy , Feldman Jarett L , Morris Michael J , Autio Karen A , Traina Tiffany A
Published: February 2015

Prostate cancer (PCa) and breast cancer (BCa) share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to PCa therapy. Recently, there has been increased interest in the role of the AR in BCa development and growth, with results indicating AR co-expression with estrogen, progesterone, and human epidermal growth factor receptors, across all intrinsic subtypes of BCa. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable to both tumor types. In this review, we offer an overview of available agents which target the AR axis in both PCa and BCa and provide insights into the novel drugs in development for targeting this signaling pathway.
Impact of minimum catch size on the population viability of Strombus gigas (Mesogastropoda: Strombidae) in Quintana Roo, Mexico
Authors: Peel Joanne R. , Mandujano María Del Carmen
Published: February 2015

The queen conch Strombus gigas represents one of the most important fishery resources of the Caribbean but heavy fishing pressure has led to the depletion of stocks throughout the region, causing the inclusion of this species into CITES Appendix II and IUCN’s Red-List. In Mexico, the queen conch is managed through a minimum fishing size of 200mm shell length and a fishing quota which usually represents 50% of the adult biomass. The objectives of this study were to determine the intrinsic population growth rate of the queen conch population of Xel-Ha, Quintana Roo, Mexico, and to assess the effects of a regulated fishing impact, simulating the extraction of 50% adult biomass on the population density. We used three different minimum size criteria to demonstrate the effects of minimum catch size on the population density and discuss biological implications. Demographic data was obtained through capture-mark-recapture sampling, collecting all animals encountered during three hours, by three divers, at four different sampling sites of the Xel-Ha inlet. The conch population was sampled each month between 2005 and 2006, and bimonthly between 2006 and 2011, tagging a total of 8 292 animals. Shell length and lip thickness were determined for each individual. The average shell length for conch with formed lip in Xel-Ha was 209.39±14.18mm and the median 210mm. Half of the sampled conch with lip ranged between 200mm and 219mm shell length. Assuming that the presence of the lip is an indicator for sexual maturity, it can be concluded that many animals may form their lip at greater shell lengths than 200mm and ought to be considered immature. Estimation of relative adult abundance and densities varied greatly depending on the criteria employed for adult classification. When using a minimum fishing size of 200mm shell length, between 26.2% and up to 54.8% of the population qualified as adults, which represented a simulated fishing impact of almost one third of the population. When conch extraction was simulated using a classification criteria based on lip thickness, it had a much smaller impact on the population density. We concluded that the best management strategy for S. gigas is a minimum fishing size based on a lip thickness, since it has lower impact on the population density, and given that selective fishing pressure based on size may lead to the appearance of small adult individuals with reduced fecundity. Furthermore, based on the reproductive biology and the results of the simulated fishing, we suggest a minimum lip thickness of ≥15mm, which ensures the protection of reproductive stages, reduces the risk of overfishing, leading to non-viable density reduction.
Clave para la determinación de exuvias pupales de los quironómidos (Diptera: Chironomidae) de ríos altoandinos tropicales
Authors: Prat Narcís , González-Trujillo Juan David , Ospina-Torres Rodulfo
Published: February 2015

The Chironomidae is a cosmopolitan family of Nematoceran flies with more than 20 000 species described. However the diversity of genera and species of the family in the Andean region beyond the 2 000m.a.s.l are scarcely known. We conducted faunal surveys and biomonitoring research in different streams of Colombia, Ecuador and Peru from May 2005 to October 2011. Based on specimens collections, and a taxonomic key was developed to identify pupae and pupal exuviae of 46 genera of midges (Diptera, Chironomidae) collected from streams at high altitude areas on the Andean tropical mountains. We included illustrations and brief taxonomic descriptions for all genera, of which several ones have not yet been formally described; in this latter case we used the nomenclature of Roback & Coffman (1983). For two genera, Cricotopus and Genus 1, keys to the most common morphospecies were provided. Results showed that in this area the chironomid assemblages are dominated by the members of the subfamily Orthocladiinae (22 genera) followed by the Chironominae (13). Six genera of Tanypodinae were identified, while only three and two genera were present from subfamilies Podonominae and Diamesinae. This key may be very useful for both studies about drift in streams, and for biomonitoring purposes.
PERCEPCIÓN DE LOS NIÑOS (AS) DE 7 A 12 AÑOS ACERCA DE LAS DROGAS EN AMÉRICA LATINA
Authors: Fernandes Moll Marciana , Sánchez Charpentier Olga
Published: February 2015

Introducción. El presente artículo tiene como objetivo analizar la percepción de los niños de 7 a12 años acerca de la temática de las drogas, durante el periodo 1992-2012. uno de los problemas más reiterativos en las poblaciones infantiles es el uso del alcohol, tabaco y demás drogas ilícitas, cuya exposición inicia a edades cada vez más tempranas, motivo por el que es fundamental la participación de equipos de trabajo en conjunto con padres, educadores, psicólogos, psiquiatras, trabajadores sociales, poderes públicos, a lo que debe aunarse una estrategia global de promoción  de la salud para enfrentar el fenómeno de las drogas en la niñez.Métodos. Para desarrollar esta investigación se empleó la revisión bibliográfica integrativa. Para recolectar información se utilizó diversos artículos completos, indexados en bases de datos LILACS y SCIELO, de los que se recuperó 54 artículos, aunque solo diez se relacionan con la temática en estudio.Resultados. En ninguno de los estudios se estableció  diferencia de percepción entre los niños (as) a partir de aspectos como  sexo, edad, condiciones económicas, sociales y familiares; no obstante, se relaciona países, sí se detectó diferencias, aunque mínimas, principalmente en lo que respecta al abordaje del tema, el cual se enfoca en el consumo en sí y no en las percepciones que construyen los niños en relación con el consumoConclusión. Los niños perciben como inapropiado el consumo de drogas tanto lícitas como ilícitas, puesto que producen múltiples consecuencias que producen alteraciones en la salud y en la apariencia física, así como bajo rendimiento escolar y deterioro en las relaciones familiares y sociales.
Las necesidades de las adolescentes madres en el contexto educativo: un estudio de caso en una institución de educación pública
Authors: Martínez Esquivel Daniel , Chaves Guillén Jennifer , Guzmán Rojas María Jacinta , Martínez López Luis , Meneses Damian , Mora Martínez Rebeca , Quesada Mora Nazira , Vargas Quesada Sofía
Published: February 2015

Introducción. El embarazo en la adolescencia es un problema de salud pública que debe ser subsanado en las generaciones presentes a partir de la educación en salud. La Enfermería no debe mostrarse ajena a este proceso, sino que debe ser sensible a las necesidades tanto de las adolescentes en riesgo como de las adolescentes embarazadas, motivo por el que en  esta investigación se planteó como pregunta ¿cuáles son las necesidades surgidas en el ámbito educativo en las adolescentes embarazadas?Método. Se diseñó un estudio cualitativo, fenomenológico. Los datos fueron recolectados mediante la técnica de grupo focal en el que participaron tres adolescentes madres. El análisis se realizó desde una perspectiva interpretativa.Resultados. Los principales resultados evidenciaron necesidades personales como uniformes que se ajusten a sus cambios físicos, necesidades de infraestructura como sillas y pupitres adecuados, un espacio específico para la lactancia, tiempo para ver a su hijo o hija y adecuación de los horarios de clase.Conclusión. Se concluye que la implementación de las políticas públicas favorecerá el respeto de los derechos de las adolescentes madres en aspectos personales, académicos y de infraestructura.
Surgimiento de la Escuela de Obstetricia en el mapa social de Costa Rica: finales del siglo XIX y principios del XX
Authors: Martínez Esquivel Daniel , Meza Benavides María De los Ángeles
Published: February 2015

Introducción. El presente artículo muestra los resultados preliminares que forman parte de la investigación “Funciones sociales de la Enfermería en los diversos procesos históricos desde la construcción de la Salud Pública en la Costa Rica contemporánea”,  cuyo propósito es analizar los hechos sociales e históricos que favorecieron la profesionalización de la Enfermería, en un primer momento, con la fundación de la Escuela de Obstetricia en 1897.Materiales y método: Este artículo responde a una investigación histórica basada en tres pasos: la revisión de fuentes primarias como la Gaceta Médica y los informes de la Junta de Caridad, y fuentes secundarias; la evaluación crítica de los datos; y la interpretación y conclusiones de los hechos.Resultados: Los hechos que favorecieron la fundación de la Escuela de Obstetricia se relacionaron con la creciente tasa de mortalidad infantil, la necesidad de institucionalizar las prácticas sanitarias e higienizar a la población para construir un Estado fuerte que promoviera el desarrollo económico, así como con la lucha que emprendió la institución médica contra las prácticas populares de atención de salud.Conclusión. Se concluye que la represión de la curandería y la partería estuvo relacionada con el poder patriarcal. Además, la fundación de la Escuela de Obstetricia se relacionó a las condiciones sociales, políticas y económicas de la época basadas en la línea de desarrollo que estaba teniendo el país
Potencial teórico, social y metodológico en los trabajos finales de graduación de la maestría de Enfermería Ginecológica, Obstétrica y Perinatal
Authors: Rojas Valenciano Ligia , López Quirós Laura , Campos González Ana Ibis
Published: February 2015

Introducción. El objetivo de este artículo es presentar los resultados del proyecto de investigación No. 421-B2-A19  en cuanto al potencial teórico, social y metodológico en los trabajos finales de graduación realizados en la maestría de Enfermería Ginecológica, Obstétrica y Perinatal. El componente de investigación en un área del quehacer de la Enfermería, cuya meta es preparar a los profesionales en enfermería clínica  acerca de utilizar diligentemente la investigación. Método. Se aplicó la investigación documental como una variante de la investigación científica cuyo objetivo fundamental es el análisis de diferentes fenómenos utilizando técnicas muy precisas de la documentación existente que, directa o indirectamente, aporte la información. Se incluyó 37 trabajos de investigación aplicada, 22 sustentados en el enfoque cualitativo y 15 en el cuantitativo, desde el año 2003 al 2011. A cada trabajo se le aplicó un análisis crítico utilizando una matriz construida a partir de elementos recomendados por CASpe para valorar documentos científicos cuantitativos (Critical Appraisal Skills Programme Español). Para el análisis crítico de los trabajos finales de investigación de corte cualitativo también se construyó una matriz que incluye aspectos del CAT (Critically Appraised Topic): EBCP (Evidence-Based Clinical Practice).Resultado. Los trabajos finales de graduación no demostraron ser significativos en el cambio o mejoramiento de la práctica profesional en términos de mejorar la calidad de atención a las personas. Solo han sido relevantes para que se gradúe un grupo grande de estudiantes. Existe poca claridad –en general- de los aspectos metodológicos de los enfoques investigativos cualitativo y cuantitativo.Conclusión. La investigación en la maestría Ginecológica, Obstétrica y Perinatal no  aporta un conocimiento enfermero sustantivo, lo cual provoca poco desarrollo disciplinar. Los trabajos finales de graduación aparentan ser solo requisito de graduación, por tanto, no contribuyen al mejoramiento de las prácticas ginecológicas, obstétricas y perinatales.
Carbon-TiO2 Nanostructures: Flame Synthesis and Characterization
Authors: De Falco Gianluigi , Commodo Mario , Pedata Paola , Minutolo Patrizia , D’Anna Andrea
Published: February 2015

The synthesis of pure titania and carbon-titania nano-powders in a premixed atmospheric fuel-rich flame was studied. The variation of the flame C/O ratio allows to produce both pure titania and carbon-TiO2 nanoparticles. Raman Spectroscopy, X-ray Diffraction, Atomic Force Microscopy, Electrical Low Pressure Impactor and Scanning Electron Microscopy were used to characterize the synthesized nano-powders, in terms of crystallinity, phase content, size and morphology. Produced nano-powders with a dimension of 25-40 nm are composed by both rutile and anatase phases, with rutile being the predominant one. Reactive Oxygen Species analysis performed on the synthesized nano-powders showed that the inclusion of carbon in the nano-powders results in a reduced adverse health effect, in terms of ROS production.
Reactive Molecular Dynamics Simulations, Data Analytics and Visualization
Authors: Vashishta Priya , Kalia Rajiv K. , Nakano Aiichiro , Li Ying , Nomura Ken-ichi , Shekhar Adarsh , Shimojo Fuyuki , Shimamura Kohei , Kunaseth Manaschai
Published: February 2015

Multimillion-atom reactive molecular dynamics (RMD) and large quantum molecular dynamics (QMD) simulations are used to investigate structural and dynamical correlations under highly nonequilibrium conditions and reactive processes in nanostructured materials under extreme conditions. This paper discusses four simulations:

1.

RMD simulations of heated aluminum nanoparticles have been performed to study the fast oxidation reaction processes of the core (aluminum)-shell (alumina) nanoparticles and small complexes.

2.

Cavitation bubbles readily occur in fluids subjected to rapid changes in pressure. We have used billion-atom RMD simulations on a 163,840-processor Blue Gene/P supercomputer to investigate chemical and mechanical damages caused by shock-induced collapse of nanobubbles in water near silica surface. Collapse of an empty nanobubble generates high-speed nanojet, resulting in the formation of a pit on the surface. The gas-filled bubbles undergo partial collapse and consequently the damage on the silica surface is mitigated.

3.

Our QMD simulation reveals rapid hydrogen production from water by an Al superatom. We have found a low activation-barrier mechanism, in which a pair of Lewis acid and base sites on the Aln surface preferentially catalyzes hydrogen production.

4.

We have introduced an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large QMD simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786,432 cores for a 50.3 million-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16,661 atoms was performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles.
Instability of dilative sand
Authors: Chu J. , Wanatowski D. , Leong W. K. , Loke W. L. , He J.
Published: February 2015

A type of pre-failure instability that occurs for medium loose to dense sand under fully drained conditions is studied in this paper. It is observed experimentally that when a specimen is sheared along a drained stress path involving a decrease in the effective mean stress, it becomes unstable after the stress path crosses an instability line (IL). The IL specifies a minimum stress ratio under which instability may occur. It is not unique but changes with the void ratio of the soil and the applied effective stresses. The instability occurring under drained conditions is different from that under undrained conditions. The differences and similarities between the two types of instability are pointed out. Practical implications of the study in analysing the failure mechanisms of granular soil slopes under various drainage conditions are discussed.
Temperature and depth mediate resource competition and apparent competition between Mysis diluviana and kokanee
Authors: Schoen Erik R. , Beauchamp David A. , Buettner Anna R. , Overman Nathanael C.
Published: February 2015

In many food webs, species in similar trophic positions can interact either by competing for resources or boosting shared predators (apparent competition), but little is known about how the relative strengths of these interactions vary across environmental gradients. Introduced Mysis diluviana shrimp interact with planktivorous fishes such as kokanee salmon (lacustrine Oncorhynchus nerka) through both of these pathways, and effective management depends on understanding which interaction is more limiting under different conditions. An “environmental matching” hypothesis predicts the ecological impacts of Mysis are maximized under cool conditions near its thermal optimum. In addition, we hypothesized Mysis is more vulnerable to predation by lake trout in relatively shallow waters, and therefore Mysis enhances lake trout density and limits kokanee through apparent competition more strongly in shallower habitats. We tested whether these hypotheses could explain food web differences between two connected lake basins, one relatively shallow and the other extremely deep. The shallower basin warmed faster, thermally excluded Mysis from surface waters for 75% longer, and supported 2.5–18 times greater seasonal production of cladoceran zooplankton than the deeper basin, standardized by surface area. Mysis consumed 14–22% less zooplankton in the shallower basin, and lower ratios of total planktivore consumption to zooplankton production (C:P) indicated less potential for resource competition with kokanee, consistent with environmental matching. Lake trout diets contained more Mysis in the shallower basin and at shallower sampling sites within both basins. The catch rate of lake trout was seven times greater and the predation risk for kokanee was 4–5 times greater in the shallower basin than in the deeper basin, consistent with stronger apparent competition in shallower habitats. Understanding how the strengths of these interactions are mediated by temperature and depth would enable managers to select appropriate strategies to address the unique combinations of conditions in hundreds of affected systems.
Novel Stabilized Enzyme Breaker for Fracturing Applications
Authors: Chopade Prashant , Fontenelle Lucas , Reddy B.R. , Coria Bianca
Published: February 2015

Enzyme breakers have been widely used in water-based fracturing fluids for more than three decades. Enzyme breakers have several significant advantages compared to traditional oxidizer chemical breakers. First, enzymes specifically break long-chain polymers without causing undesirable damage to the wellbore, formation, or fracturing equipment. Second, because of the catalytic nature of the enzyme, they are not consumed, thereby requiring minimal amounts. Third, enzymes are non-toxic compared to oxidant breakers. However, enzymes operate under a narrow pH range and often become inactive at high pH values. In addition, at elevated temperatures, their activity decreases or completely diminishes as a result of denaturing. This paper discusses a new method to extend the breaker activity of a mannanase enzyme to higher pH and temperatures by the addition of lignin-based additives.

Results show that the addition of lignosulfonates stabilizes the enzyme at an elevated temperature and pH, thereby extending enzymes breaker performance beyond what was previously achievable. Another aspect of fracturing fluid breakers that is difficult to control is break time. Generally, varying the amount of breaker provides customizable break times. For example, if a faster break time is required, then a larger amount of breaker is added to the fluid. However, enzymes are highly expensive, and the use of greater amounts to achieve a faster break adds significant cost. On the other hand, if lesser amounts of enzyme are used, extended break times are achievable, but the polymer breakdown becomes incomplete, which could lead to formation or propped fracture permeability damage. In this study, it was possible to modulate the break times of guar-based fluids by varying the amount of lignosulfonate and keeping the enzyme loading constant. The higher loading of the less-expensive lignosulfonate aids in faster breaking of the fluid viscosity. Consequently, this approach is more economical as it requires less enzyme loading. Additionally, the polymer breakdown is complete despite the low amounts of the enzyme used. The effects of different structural types of sulfonated lignins on enzyme activity are also discussed.

To the best of the authors' knowledge, there are no mannanase enzyme stabilizer additives available in the oilfield industry. Introduction of these new additives will aid in improving higher temperature and pH tolerance of mannanase enzyme breakers.
Risk of diarrhoea from shallow groundwater contaminated with enteropathogens in the Kathmandu Valley, Nepal
Authors: Shrestha Sadhana , Haramoto Eiji , Malla Rabin , Nishida Kei
Published: February 2015

Shallow groundwater is the main water source among many alternatives in the Kathmandu Valley, Nepal, which has a rapidly growing population and intermittent piped water supply. Although human pathogens are detected in groundwater, its health effects are unclear. We estimated risk of diarrhoea from shallow groundwater use using quantitative microbial risk assessment. Escherichia coli, Giardia cyst and Cryptosporidium oocyst levels were analysed in dug and tube wells samples. E. coli concentrations were converted to those of enteropathogenic E. coli (EPEC). Risks from EPEC in dug wells and from Cryptosporidium and Giardia in both dug and tube wells were higher than the acceptable limit (<10−4 infections/person-year) for both drinking and bathing exposures. Risk from protozoan enteropathogens increased the total risk 10,000 times, indicating that ignoring protozoans could lead to serious risk underestimation. Bathing exposure considerably increased risk, indicating that it is an important pathway. Point-of-use (POU) water treatment decreased the risk six-fold and decreased risk overestimation. Because removal efficiency of POU water treatment has the largest impact on total risk, increasing the coverage and efficiency of POU water treatment could be a practical risk management strategy in the Kathmandu Valley and similar settings.
Evaluation of quantitative polymerase chain reaction assays targeting Mycobacterium avium, M. intracellulare, and M. avium subspecies paratuberculosis in drinking water biofilms
Authors: Chern Eunice C. , King Dawn , Haugland Richard , Pfaller Stacy
Published: February 2015

Mycobacterium avium (MA), Mycobacterium intracellulare (MI), and Mycobacterium avium subsp. paratuberculosis (MAP) are difficult to culture due to their slow growing nature. A quantitative polymerase chain reaction (qPCR) method for the rapid detection of MA, MI, and MAP can be used to provide data supporting drinking water biofilms as potential sources of human exposure. The aim of this study was to characterize two qPCR assays targeting partial 16S rRNA gene sequences of MA and MI and use these assays, along with two previously reported MAP qPCR assays (IS900 and Target 251), to investigate Mycobacterium occurrence in kitchen faucet biofilms. MA and MI qPCR assays demonstrated 100% specificity and sensitivity when evaluated against 18 non-MA complex, 76 MA, and 17 MI isolates. Both assays detected approximately 1,000 cells from a diluted cell stock inoculated on a sampling swab 100% of the time. DNA analysis by qPCR indicated that 35.3, 56.9 and 11.8% of the 51 kitchen faucet biofilm samples collected contained MA, MI, and MAP, respectively. This study introduces novel qPCR assays designed to specifically detect MA and MI in biofilm. Results support the use of qPCR as an alternative to culture for detection and enumeration of MA, MI, and MAP in microbiologically complex samples.
Monitoring of chlorination disinfection by-products and their associated health risks in drinking water of Pakistan
Authors: Abbas Sidra , Hashmi Imran , Rehman Muhammad Saif Ur , Qazi Ishtiaq A. , Awan Mohammad A. , Nasir Habib
Published: February 2015

This study reports the baseline data of chlorination disinfection by-products such as trihalomethanes (THMs) and their associated health risks in the water distribution network of Islamabad and Rawalpindi, Pakistan. THM monitoring was carried out at 30 different sampling sites across the twin cities for 6 months. The average concentration of total trihalomethanes (TTHMs) and chloroform ranged between 575 and 595 μg/L which exceeded the permissible US (80 μg/L) and EU (100 μg/L) limits. Chloroform was one of the major contributors to the TTHMs concentration (>85%). The occurrence of THMs was found in the following order: chloroform, bromodichloromethane > dibromochloromethane > bromoform. Lifetime cancer risk assessment of THMs for both males and females was carried out using prediction models via different exposure routes (ingestion, inhalation, and dermal). Total lifetime cancer risk assessment for different exposure routes (ingestion, inhalation, and skin) was carried out. The highest cancer risk expected from THMs seems to be from the inhalation route followed by ingestion and dermal contacts. The average lifetime cancer risk for males and females was found to be 0.51 × 10−3 and 1.22 × 10−3, respectively. The expected number of cancer risks per year could reach two to three cases for each city.
Davorin Jenko and Stevan st. Mokranjac. Biographical fragments. A contribution to cultural remembrance
Authors: Tomasevic Katarina
Published: February 2015

This paper contributes to the marking of the centenary of the death of two
significant composers and conductors - Davorin Jenko (1835-1914) and Stevan
St. Mokranjac (1856-1914). Although belonging to different generations, Jenko
and Mokranjac were simultaneously active in Serbian culture over the course
of almost four decades. This was a very dynamic and fruitful period, marked
by historical and political unrests and by the intense processes of searching
for Serbian national/ cultural identity. Divided into several fragments, the
article identifies the points of intersection in their biographies, examining
the delicate nature of their relationship in the context of the discourses of
nationalism. Special attention is paid to the facts from the history of the
Belgrade Singing Society and the National Theatre, but also to the
manifestations by means of which a tradition of cultural remembrance of these
two artists is maintained in Serbia in 2014.
Criteria of ‘authenticity’ in traditional Georgian musical performance
Authors: Gabisonia Tamaz
Published: February 2015

Today we often use term ?authentic? in relation to different appearances of
Georgian folk music. Along with the unambiguous meaning ?real? this term also
has other meanings: ?ethnic?, ?rural?, ?old?, ?function of usual
environment?, ?traditional-stylistic?, ?authoritative?, or ?reproductive?. In
spite of some interconnections that arise from the term ?authentic? and its
other meanings, the most relevant way to apply this popular term for
performers and audiences of ?real folklore? is traditionality. This factor is
manifested in the following contexts: a) performer (receiver and distributor
of tradition, unobtrusively and orally), b) motivation/function
(representative and spontaneous function, hereditary, utilitarian and
aesthetic-daily motivation), c) repertoire (compliance of musical and verbal
text?s sample with its social function, eluding canonized versions), d)
expression (adequate articulation, performing regulation which is not
determined by the stage, traditional instrument etc.). The problem of
authenticity is more successfully regulated in traditional Georgian church
music than in folk music. For the latter, in this regard the special
difficulty is caused by identification of modern trends that contain folk
motifs. The most popular among them is distinctive, with its stylistic
reminiscent layer from the Eastern Georgian Mountains, which we refer as
?para-folkore?. Notwithstanding the fact that Georgian folklore is not
centrally authorized, modernization of folklore samples and also those
manifestations of post-folklore that are further away from the traditional
motifs attract a wide range of listeners. Essentially, the meaning of
?authentic? in the Georgian ethno-musical context is presented as performance
of the traditional rural repertoire with traditional articulation. However,
we think that it is convenient for the criteria of traditional, usual
environment to be added to this perspective.
Performing sound of the past: Remix in electronic dance music culture
Authors: Cvijanovic Irina
Published: February 2015

The term remix, defined as an activity of taking data from pre-existing
materials to combine them into new forms according to personal taste,
relates to various elements and areas of contemporary culture. Whichever
model used, consideration of the remix depends on recognition of
pre-existing cultural codes. Therefore, as a second layer, the remix relies
on the authority of the original and it functions at the meta-level. The
audience may see a trace of history with the pre-existing object and the
meaning creates in the viewer(s), reader(s), listener(s) or, in the
contemporary world of DJs and popular electronic dance music culture - in
dancer(s). With the aim of specifying modes of creating particular ambients,
this paper will consider and examine the song Why Don?t You? remixed by
Marko Milicevic, a Serbian DJ also known as Gramophonedzie, and illuminate
how material from the past can create a constructive (musical) dialogue.
The principle of laughter in Byelorussian vocal culture as a form of reflection on images of the world
Authors: Tawlai Galina
Published: February 2015

This paper considers particular ways of organizing musical material in songs
connected with the culture of laughter, as well as the coordination and
interaction of different artistic spheres in this group of traditional
Belarus song forms. Our long standing, complex ethno-musicological research,
constant documentations of our own field work, comparison of ritual songs?
stylistics with their respective cognitive methods, together with
observations and generalizations made by the real exponents of traditional
Belarus song have given us the possibility to hear and recognize this strict,
logically-adjusted selection of forms of musical expressiveness among folk
melodies.
The appearance of concept albums in Yugoslav popular music: Kamen na kamen - long play records
Authors: Jovanovic Jelena
Published: February 2015

It is commonly understood that a concept album is ?a studio album where all
musical or lyrical ideas contribute to a single overall theme or unified
story? (Shuker 2002: 5). In this paper this term will be used to denote an
album containing extra-musical themes and not simply collections of
compositions defined only by genre or theme. In order for an album to belong
to this category, it must have taken a thematic unity realized by the common
content (thematically) of its compositions and common musical means. Although
the beginnings of such creative trends can be traced from 1940, the 1960s and
1970s brought the most influential releases of this kind, especially The
Beatles? album Sgt. Pepper?s Lonely Hearts Club Band (1967), which has had a
great impact on many authors. As far as is known, the topic of concept albums
in Yugoslavia has not yet been elaborated, so this article seems to be the
first dedicated to this subject. It seems that in Yugoslavia there had been
albums with elements of concept released before the appearance of the Kamen
na kamen group album in 1973, entitled LP-60993 (Zagreb: Jugoton). The author
of the album was Nikola Borota Radovan. After that, a double LP by the same
ensemble and songwriter appeared in 1975 entitled OOUR/AVNOJ (RTV Ljubljana),
with even more clearly expressed characteristics of concept. The aim of this
article is to show that the thematic and conceptual elements of these
editions are firmly connected to those of the concept album. These LPs were
formed within the following thematic and contextual frames: 1) Borota`s
general inclination towards folklore tradition(s) as a permanent source of
inspiration, 2) models among the greatest popular music works that influenced
his writing projects, primarily The Beatles? concept albums, and 3) social,
economic and political circumstances in Yugoslavia at the time when these
albums appeared. Even if it is not strictly a concept album in the full
sense, the album LP- 60993 might be regarded as the first album with elements
of concept published by a Yugoslav author, according to all the criteria and
analyzed results. The elements that show a clear connection to the concept
are as follows: leading subject(s)/idea(s) that demand(s) the order of
compositions, organization of musical elements and motives on macro- and
micro-levels (to produce formal and thematic unity), elements of narrative
and musical/sound symbols, including elements of musique concr?te.
Emergence of ethnochoreology internationally: The Jankovic sisters, Maud Karpeles, and Gertrude Kurath
Authors: Dunin Elsie
Published: February 2015

A fifty-year (1962-2012) period has been shown as a history of
ethnochoreology supported by living memories of members of the International
Council for Traditional Music (ICTM) Study Group on Ethnochoreology.
Recently uncovered and juxtapositioned correspondence of three predecessors
within earlier years of the International Folk Music Council (IFMC) broadens
the history. This article reveals the emergence of ethnochoreology during
the 1950s with publications of the two Jankovic sisters in Serbia with that
of Gertrude Kurath in the United States, alongside correspondence with Maud
Karpeles, the unheralded founder of the IFMC.
Drivers of the Use and Facilitators and Obstacles of the Evolution of Big Data by the Audit Profession
Authors: Alles Michael G.
Published: February 2015

SYNOPSIS

Big Data is one of the most important developments in management practice today, with McKinsey Global Institute (2011) arguing that it will fundamentally change business. Forbes (2013) states that “the market for Big Data will reach $16.1 billion in 2014, growing 6 times faster than the overall information technology (IT) market.” Given the growing significance of Big Data as a business tool, this paper considers the extent to which Big Data will be embraced by the audit profession and how that usage will evolve over time. I put forward the hypothesis that auditors cannot stray too far from the practices of their clients since their credibility with and respect of those clients are the basis of the value added that they provide. Hence, if Big Data becomes an essential business tool, then inevitably it will have the same impact on auditing, albeit, perhaps later and with a more muted reaction. Analysis also indicates that American and international auditing standards, technological advances, and market forces are some of the facilitators and obstacles that will determine the use of Big Data by auditors and that will shape how that usage will evolve over time.
The Center Cannot Hold: The AICPA and Accounting Professional Leadership 1997–2013
Authors: Sellers R. Drew , Fogarty Timothy J. , Parker Larry M.
Published: February 2015

SYNOPSIS

Trade associations should play an integral role in defining and defending the legitimacy and jurisdiction of a profession. In addition, they should provide a field upon which individuals can rise above the confines of their organizations and grow their professional leadership capacities. Evidence in the literature suggests that U.S. accounting conformed to this pattern under the auspices of the American Institute for Certified Public Accountants (AICPA). However, various recent events have transpired that reduce the confidence that this continues to be the case. Using network analysis on longitudinal data from 1997 to 2013, this paper documents an increasingly fragmented and isolated leadership structure. This finding suggests the reduced influence of the AICPA. Surprisingly, this decline has not been offset by the stronger influences of the large international firms. Implications for the profession are discussed.
Does Systematic Selection Lead to Unreliable Risk Assessments in Monetary-Unit Sampling Applications?
Authors: Hoogduin Lucas A. , Hall Thomas W. , Tsay Jeffrey J. , Pierce Bethane Jo
Published: February 2015

Monetary-unit sampling (MUS) applications using systematic selection are evaluated via the use of a statistical function that describes the distributional properties of simple random samples. Because systematic selection produces a significantly smaller set of potential samples, its distributional properties differ from those of simple random selection. Whether these distributional differences lead to unreliable MUS risk assessments is the focus of our study. Our findings indicate that risk assessments of MUS applications using systematic selection exhibit material error at a nontrivial rate. We also find that risk assessment reliability declines as sampling interval width decreases, error tainting magnitudes increase, and errors are increasingly concentrated in population members with larger recorded values. Given the availability of alternative sample selection methods, our findings suggest that auditors should avoid the use of systematic selection in MUS applications.
A Gain by Any Other Name: Accounting for a Bargain Purchase Gain
Authors: Kohlbeck Mark J. , Smith Thomas J.
Published: February 2015

Students gain insight into a unique accounting treatment in acquisition accounting by completing this case—that of a bargain purchase gain (BPG). In December 2007, the Financial Accounting Standards Board (FASB) revised accounting for business combinations when they promulgated Statement of Financial Accounting Standard No. 141R, Business Combinations. Under the revised standard, acquirers record net assets of the acquiree at their respective fair market values at the time of acquisition and recognize the excess of net assets over the consideration paid as a BPG included in income from continuing operations. This case takes place after the acquisition is negotiated and the consideration is agreed upon. Students are required to estimate fair values of acquired net assets based on the information provided, determine whether goodwill or a bargain purchase gain exists, and evaluate the impact of this transaction on the financial statements. The case also requires students to consider subjectivity within the analysis, as well as to identify potential incentives that may influence certain estimates and judgments that managers make. The case is appropriate for accounting courses where business combinations, goodwill, and fair value estimation are discussed.