bluuebunny/crossref_metadata_2025 huggingface dataset:
Signature Investigation of Typical Faults on Francis Turbines
Authors: Støren G K , Dahlhaug O G , Solemslie B W
Published: August 2020

Hydropower is facing new operational strategies as the increasingly competitive power market demands for higher flexibility. Consequently, turbines are forced to handle tougher operation and are prone to more frequent degradation. By implementing a real-time monitoring system, a better understanding of the behavior of components may contribute to detect faults at an earlier stage, reducing potential downtime. This paper will present the work done in the preliminary work of the author’s master thesis. The focus has been to characterize the normal behaviour of a Francis turbine through amplitude and frequency analysis. Steady-state measurements of pressure pulsations have been conducted on the Francis test-rig at the Waterpower laboratory at NTNU. Different hydraulic phenomena and respective frequencies were identified. In addition, the results revealed several unexpected frequencies and suspicious observations, and potential sources of these are discussed. Possible fault detection schemes based on peak-peak and frequency analysis are suggested. Alarm should be raised in case of mismatches in sensor relations, magnitude variations or if new harmonics or frequencies appears.
Uncertainty evaluation of efficiency measurement in laboratory conditions
Authors: Dhakal Prabin , Adhikari Manish , Thapa Biraj Singh , Kayastha Atmaram , Sapkota Prajwal , Dahal Dadi Ram
Published: August 2020

Uncertainty is a parameter associated with the result of a measurement, which characterizes the dispersion of the values that could reasonably be attributed to the measurand. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty, such as standard deviation or uncertainty band.

The identification of uncertainty of individual sensors and standardization in calibration process is under progress in Turbine Testing Lab (TTL) at Kathmandu University (KU). The lab aims to establish a Francis turbine test rig and procedures that meet the standards set by International Electrotechnical Commission (IEC). This needs a major investment on calibration systems and development of procedures to estimate the uncertainty in measurement more precisely than ever before.

This study aims to identify the sources of uncertainty and their quantification for efficiency measurement systems at laboratory condition. The study is done on the 14 kW Francis turbine project at TTL, KU. Based on different published papers regarding uncertainties, type A and type B uncertainties were evaluated separately and then combined to get combined uncertainty of each components. The uncertainty in efficiency was then calculated using the rules of uncertainty calculation.

In this paper, the standard method is illustrated to evaluate the uncertainties in sensor-based measurement system. The same method is used in investigation of uncertainty to the extent it was possible and feasible in the lab i.e. study could be mainly focused only on torque transducer. The value of efficiency at 1300 rpm is calculated to be 66.7% ± 0.35%, where ± 0.35% represents the uncertainty in efficiency for the same rpm value. The results indicate uncertainty level unforeseen close to meet the IEC standards which could be result of including only parts of uncertainties. All uncertainties should be evaluated for future research papers.
An Overview of Design and Construction practices of Himalayan Hydropower tunnels
Authors: Karki Sujan , Chhushyabaga Bimal , Khadka Shyam Sundar
Published: August 2020

Due to steep terrain and fast flowing rivers in the Himalayan region of Nepal, medium to mega size hydropower projects are constructing day-by-day. Tunnel is one of the best and short routes for water conveyance system for power production. Hundreds of kilometers of tunnels have been constructed and new tunnels are planned in this region. The availability of high head for hydropower generation, the tunnel cross sections are relatively small, up to 6 m diameter in size, and there is high rock cover above the tunnel alignment. This paper focuses on the design and construction practices of hydropower tunnel passes through weak rock mass with high rock cover of the Himalayan region of Nepal. Most of the hydropower tunnels undergo excessive deformation and support failure during the tunnel construction, which delayed the project as well as increases the cost of project. The paper first discusses the available construction practices for tunnel and underground structures. In the second part, the current practice employed during construction in the Himalayas is discussed along with the shortcomings of the methods and how it is addressed in the region.
Tunnel support design in fault zone in hydropower project in the Nepal Himalaya: a case study
Authors: Chhushyabaga Bimal , Karki Sujan , Khadka Shyam Sundar
Published: August 2020

Tunnelling through faulted rock mass is associated with long lasting displacements, stability problems, overburden squeezing, high deformations and dynamic stress conditions. With the dominance of faults in the Nepal Himalaya, determination of behaviour of the rock mass around tunnels and physical parameters for tunnel support is very challenging and demanding. Tunnel support and rock mass stability in tunnel are always dominated by fault. In this paper a hydropower tunnel in the vicinity of a fault has been used as a case study for the design and application of tunnel support. Rock mass is characterized, behaviour of the unsupported rock mass is evaluated, and support is designed. Geological Strength Index (GSI) is used to characterize the rock mass and a methodology has been used to design the support using numerical analysis The system behaviour of the rock mass and the tunnel support are analysed for the various combinations of geomechanical ground conditions. The displacement, stress, yielded elements and plastic region are studied for the influence of the fault and its stress conditions of the designed tunnel supports.
Application of Reverse Engineering method to model eroded Francis runner.
Authors: Sedai Ashish , Thapa Biraj Singh , Thapa Bhola , Kapali Aman , Qian Zhongdong , Guo Zhiwei
Published: August 2020

Damage of runners and other components of hydro turbine by sediment erosion and cavitation erosion is an inevitable problem associated with hydropower established in a region with mountainous topology. The paper attempts to investigate the suitability and sustainability of the reverse engineering method for the design of the eroded Francis runner. This manufacturing technology is in a progressive phase of development in various parts of the world, so research scholars have been constantly working on the concept to increase the speed and efficiency of the method. The case investigation was conducted on Puwa-Khola 1HPP eroded Francis runner. The paper investigates reverse engineering design methodology of the eroded runner and discusses scope and limitation in the utilization of method at Hydropower sector. Also, the paper suggests suitable 3D scanning techniques, reverse engineering tools, and optimization methods for obtaining mathematically sound models without any hydraulic profile deviation between actual and reversed engineered model.
Experimental and CFD study of influence of sediment size on efficiency of hydrocyclone for use as sediment separation device
Authors: Kapali A. , Neopane H.P. , Chitrakar S. , Kayastha A. , Shrestha O.
Published: August 2020

Hydrocyclones are separation devices used in several industrial applications for separation of particles even smaller than 5 μm. However, this paper presents the feasibility of using hydrocyclone as a sediment separation system in hydropower plants, as well as in the development of a non-recirculating type of an erosion test rig. The design of the experimental set up is a part of the erosion test rig that consists of a discrete sediment feed and separation system to conduct erosion related research. Experimental as well as numerical investigation of effect of sediment particles sizes on overall separation efficiency of hydrocyclone geometry is conducted. Hydrocyclone’s overall efficiency is depicted by measuring the particle separation and its variation with sediment particle’s size. The results indicated that under appropriate flow conditions, particles below 200 μm that are responsible for turbine wear can be separated and prevented from entering into the system. Also, it can be concluded that this system can be used to develop non-recirculating type of erosion test rig.
Method of erosion prediction hill diagram to investigate the performance of Francis turbine operated in sediment laden water
Authors: Lama Ram , Gautam Saroj , Chitrakar Sailesh , Neopane Hari Prasad , Thapa Biraj Singh
Published: August 2020

Sediment erosion problem in hydropower plants located under Himalayan regions of Nepal is inevitable. Reliance to the performance curves from model test data in terms of hydraulic efficiency cannot predict the actual performance in context of sediment laden hydropower projects in Nepal. This paper presents novel technique to predict the erosion affecting regions in various operating points in terms of sediment erosion hill diagram. A 2-D representation of erosion rate in several operational points is presented in this paper. This representation is compared with the efficiency characteristics of the same turbine that will be useful for considering the compromise between efficiency and erosion wear for erosion affected hydropower projects. A reference hydropower projects severely affected with sediment erosion is chosen for this study. Using suitable numerical modelling technique, performance of the turbine is calculated in terms of efficiency. Similarly, area averaged erosion rate in the walls of the numerical model was computed at various operating condition. It gives the idea that the turbine can be operated in variable speed operation that in one hand improves the efficiency and minimizes the erosion effects as well.
Green Hydrogen as a Future Multi-disciplinary Research at Kathmandu University
Authors: Thapa Biraj Singh , Thapa Bhola
Published: August 2020

Over 100 million tons of hydrogen are produced every year for a range of industrial purposes. The vast majority of this industrial hydrogen is produced from coal gasification or steam methane reforming, both of which need a lot of energy and generate significant carbon dioxide emissions. A much smaller proportion of hydrogen is produced from the electrolysis of water, which can be a far more sustainable and clean method if the electricity is produced from renewable sources. While the urgency of greenhouse gas emission mitigation has increased, many countries have begun to take action to decarbonize their economies. Nepal is expected to have about a 3000 MW electricity surplus by the Year 2030. It is a time to explore alternative use of electricity to make hydropower projects financially feasible. Hence it is also high time to investigate Hydropower-to-Hydrogen (H2H) technology and transfer the relevant knowledge in the region. Kathmandu University (KU) has been leading to initiate and institutionalize the new academic programs and research avenues to address the future need for this country. KU has played a role model to introduce and establish innovative and unique programs in engineering education in Nepal since it was established in 1994. Since the establishment period, KU carried the vision to establish itself as a research-based university. KU has carried the objective to design its academic programs, courses, and curricula to directly contribute to the research problem the industry or society has been facing. The intuitional realization that Green Hydrogen (GH) is the future academic and research need of this country will be the far-slightness of KU.
Structural change to the persistence of the urban heat island
Authors: Dupuis Debbie J , Trapin Luca
Published: August 2020

The term urban heat island (UHI) is used to describe the effect of urban temperatures rising several degrees above concurrent temperatures in surrounding suburban or rural areas. This is typically assessed through records of daily extreme temperatures. However, on a hot day the temperature can exceed an extreme threshold for several consecutive hours, forming a cluster of extremes. We use the statistical theory of extreme values combined with a model that allows structural breaks to show that there has been a significant upward shift in the length of clusters in New York City. No such shift is found at a Connecticut location where the usual UHI assessment indicates that the two sites are comparable. Our study is the first to highlight this danger of the UHI. Prolonged exposure to extreme temperatures has deleterious effects on both health and the environment.
Momentum-dependence in the infinitesimal Wilsonian renormalization group
Authors: Helias Moritz
Published: August 2020

Wilson’s original formulation of the renormalization group is perturbative in nature. We here present an alternative derivation of the infinitesimal momentum shell renormalization group, akin to the Wegner and Houghton scheme, that is a priori exact. We show that the momentum-dependence of vertices is key to obtain a diagrammatic framework that has the same one-loop structure as the vertex expansion of the Wetterich equation. Momentum dependence leads to a delayed functional differential equation in the cutoff parameter. Approximations are then made at two points: truncation of the vertex expansion and approximating the functional form of the momentum dependence by a momentum-scale expansion. We exemplify the method on the scalar φ
4-theory, computing analytically the Wilson–Fisher fixed point, its anomalous dimension η(d) and the critical exponent ν(d) non-perturbatively in d ∈ [3, 4] dimensions. The results are in reasonable agreement with the known values, despite the simplicity of the method.
TiO2 Synthesis Anatase Phase with The Sol-gel Process at Room Temperature
Authors: Argüelles-Lucho P , Pérez-Cuapio R , Woo-Garcia R M , García-González L , Pacio M. , López-Huerta F
Published: August 2020

Titanium oxide (TiO2) film was deposited on 304 stainless steel substrates using the spin coating technique. The synthesis of the deposited solution was with the sol-gel method at room temperature, using titanium isopropoxide as a precursor. Obtained film was thermally treated at temperatures of 500 °C, 550 °C and 600 °C. The X-ray diffraction (XRD) analysis confirmed the crystallinity of the film in the anatase phase, with the highest intensity at the plane (101). Moreover, the crystallite size increased with the rising temperature of the thermal treatment. The thickness of the deposited film was obtained with profilometry being: 1 µm for the 500 ºC film, 1.2 µm for the 550 ºC film, and 1.5 µm for the 600 ºC film. Raman spectroscopy measurements showed vibrational modes at 144, 399, 519 and 638 cm−1, characteristic of the TiO2 anatase phase. The obtained results showed that these films have a high potential for gas sensor applications due to their surface-to-volume ratio after obtaining the size of nanometric crystallite.
Smart Materials Vis-à-vis Metamaterials
Authors: Qadeer Malik Malik Abdul
Published: August 2020

Smart materials are custom-designed materials that have certain properties that can undergo significant changes as guided through external influence, such as pressure, temperature, pH, electric or magnetic fields. One of the most amazing developments in the smart materials is that of metamaterials. The origin of Meta stems from Greek meaning “beyond”. Metamaterials have rare properties not found in natural occurring materials such that their properties are based on their structure rather than material of their composition. These materials find applications in many fields like public safety, sensors, battlefield communication, ultrasonic devices, solar power equipments, and remote aerospace applications. A synthetic composite material with a structure such that it possesses properties being unusual in natural materials specially a negative refractive index-these materials scatter electromagnetic wave unlike any known material. Thus the shape of the wave emerging from the metamaterials is entirely different from a conventional wave. Besides having a myriad of applications, these materials have the remarkable ability to bend light which can make airplanes, tanks and submarines invisible resulting in the epitome of stealth capability. Metamaterials now find recognition as an enabling technology being the most exciting research area at the crossroads between photonics and nanoscience. Without any exaggeration, the present era is the century of metamaterials. This paper, inter alia, highlights the significance of metamaterials in general and its stealth capabilities for defence sector in particular.
Synthesis and Characterization of Thin TiO2 Films Using the Sol-gel dip Coating Method
Authors: Woo-Garcia R M , García-González L , Argüelles-Lucho P , Guarneros-Aguilar C , Cervantes B , Herrera-May A L , López-Huerta F
Published: August 2020

TiO2 titanium oxide is a material with many applications, due to its electronic and optical properties, the characterization of the nanostructures developed with this material is carried out in order to determine its physical, chemical, and mechanical properties. This article presents the results of TiO2 multilayered thin film deposited in Corning glass substrate with the immersion technique using the Sol-gel dip coating method. The quality of the film strongly depends on the internal forces of the polymeric chains which lead to viscosity, gravitational force, surface tension, and gravity as an efficient form of obtaining TiO2 thin film. The film was submitted to thermal treatment of 400 ºC for 2 hours. The results of the experiment show film with a thickness from 139 to 171 nm that features anatase phase, a crystalline quality that corresponds to the number of deposited layers and have a bandgap close to 3.5 eV. The results show that TiO2 thin film can be used in applications that require high permittivity or high transmittance.
The effect of forced oscillations on the kinetics of wave drift in an inhomogeneous plasma
Authors: EROFEEV V I
Published: August 2020

The kinetics is analyzed of the drift of non-potential plasma waves in spatial positions and wavevectors due to plasma’s spatial inhomogeneity. The analysis is based on highly informative kinetic scenarios of the drift of electromagnetic waves in a cold ionized plasma in the absence of a magnetic field (Erofeev 2015 Phys. Plasmas
22 092302) and the drift of long Langmuir waves in a cold magnetized plasma (Erofeev 2019 J. Plasma Phys.
85 905850104). It is shown that the traditional concept of the wave kinetic equation does not account for the effects of the forced plasma oscillations that are excited when the waves propagate in an inhomogeneous plasma. Terms are highlighted that account for these oscillations in the kinetic equations of the above-mentioned highly informative wave drift scenarios.
Test parameters optimization for constrained spray forming of aluminum alloy based on artificial neural network
Authors: Liu Yingli , Yao Changhui , Yin Jiancheng
Published: August 2020

Spray deposition with following continuous extrusion (SD-CE) forming technique is a novel technology that combines spray forming and continuous extrusion. Optimization of test parameters for spray deposition is an important part of SD-CE. In this study, Al-20Si alloy was produced by spray forming at different melt temperature and gas pressure, and obtained grain diameter of 8 group primary silicon phase. Based on the experimental results, an Artificial Neural Network (ANN) with single hidden layers composing of 10 neurons was employed to simulate optimizing of test parameters for spray deposition. The inputs of the model are melt temperature and gas pressure. The output of the model is grain diameter. Finally, the minimum relative error of grain diameter is 0.09%, the maximum relative error is 8.38%, and error majority concentrate within 3.80%, the average absolute relative error(AARE) is 1.04%, R is 0.097, the error is small. The optimal test parameters for spray deposition are melt temperature(829 °C) and gas pressure(0.2 MPa). The results indicate that the ANN model is an easy and practical method to optimize the test parameters for spray deposition of Al-20Si alloy. Thereby this model is a useful reference for optimizing the test parameters of SD-CE
Waveguide controlled long range surface plasmon-polariton refractive index sensor
Authors: Sharma Vinod K
Published: August 2020

A long range surface plasmon-polariton resonance (LRSPPR) based refractive index sensor (for biomolecular interaction study applications) with ultrahigh sensitivity and extremely narrow resonance dips with very small full width at half maximum (FWHM, w) is proposed. The theoretical analysis of the sensitivity for spectral and angular interrogations is presented. The structure consists of a MgF2 prism and a plasmonic waveguide (consisting of a metal cladded high index dielectric waveguide) separated by a low index dielectric layer. It is shown that both angular and spectral sensitivities increase nonlinearly with increase in analyte index. Angular sensitivity with FWHM = 0.009°, ranges from 340°/RIU to 505°/RIU for analyte index variation from 1.360 to 1.368 and spectral sensitivity with FWHM = 3 nm, ranges from 1.79 × 105 nm RIU−1 to 2.60 × 105 nm RIU−1 for analyte index variation from1.361 00 to 1.361 10. The sensitivities (S) and the figures of Merit of the proposed sensor are the highest obtained so far (to our knowledge).
In-hospital adverse drug reactions in older adults; prevalence, presentation and associated drugs—a systematic review and meta-analysis
Authors: Jennings Emma L M , Murphy Kevin D , Gallagher Paul , O’Mahony Denis
Published: August 2020

Background

the prevalence of adverse drug reactions (ADRs) in hospitalised older patients, their clinical presentations, causative drugs, severity, preventability and measurable outcomes are unclear, ADRs being an increasing challenge to older patient safety.

Methods

we systematically searched PubMed, Embase, EBSCO-CINAHL, the Cochrane Library, ‘rey’ literature and relevant systematic review bibliographies, published from database inception to March 2020. We included any study reporting occurrence of in-hospital ADRs as primary or secondary outcomes in hospitalised older adults (mean age ≥ 65 years). Two authors independently extracted relevant information and appraised studies for bias. Study characteristics, ADR clinical presentations, causative drugs, severity, preventability and clinical outcomes were analysed. Study estimates were pooled using random-effects meta-analytic models.

Results

from 2,399 abstracts, we undertook full-text screening in 286, identifying 27 studies (29 papers). Final analysis yielded a pooled ADR prevalence of 16% (95%CI 12–22%, I2 98%,τ2 0.8585), in a population of 20,153 hospitalised patients aged ≥65 years of whom 2,479 patients experienced ≥ one ADR. ADR ascertainment was highly heterogeneous. Almost 48.3% of all ADRs involved five presentations: fluid/electrolyte disturbances (17.3%), gastrointestinal motility/defaecation disorders (13.3%), renal disorders (8.2%), hypotension/blood pressure dysregulation disorders/shock (5.5%) and delirium (4.1%). Four drug classes accounted for 57.8% of causative medications i.e. diuretics (19.8%), anti-bacterials (14.8%), antithrombotic agents (12.2%) and analgesics (10.9%). Pooled analysis of severity was not feasible. Four studies reported the majority of ADRs as preventable (55–95%).

Conclusions

on average, 16% of hospitalised older patients experience significant ADRs, varying in severity and mostly preventable, with commonly prescribed drug classes accounting for most ADRs.
Awareness of the use of hyponatraemia-inducing medications in older adults with hyponatraemia: a study of their prevalent use and association with recurrent symptomatic or severe hyponatraemia
Authors: Jun Kwanghee , Kim Yujin , Ah Young-Mi , Lee Ju-Yeun
Published: August 2020

Background

Cautious use or avoidance of hyponatraemia-inducing medications (HIMs) is recommended in older patients with hyponatraemia.

Objective

To evaluate the use of HIMs after treatment for symptomatic or severe hyponatraemia and to investigate the impact of HIMs on the recurrence of symptomatic or severe hyponatraemia in older patients.

Design and settings

A cross-sectional and nested case–control study using data obtained from national insurance claims databases.

Methods

The rate of prescribing HIMs during the 3 months before and after the established index date was analysed in a cross-sectional analysis. Multivariable logistic regression was performed to investigate the association between HIM use and recurrence of symptomatic or severe hyponatraemia after adjusting for covariates in a case–control study.

Results

The cross-sectional study included 1,072 patients treated for symptomatic or severe hyponatraemia. The proportion of patients prescribed any HIMs after hyponatraemia treatment decreased from 76.9 to 70.1%. The prescription rates significantly decreased for thiazide diuretics (from 41.9 to 20.8%) and desmopressin (from 8.6 to 4.0%), but the proportion of patients prescribed antipsychotics increased from 9.2 to 17.1%. Of 32,717 patients diagnosed with hyponatraemia, 913 (2.8%) showed recurrent hyponatraemia. After adjusting for comorbid conditions, the use of any HIMs including proton pump inhibitors [adjusted odds ratio (aOR) 1.34, 95% confidence interval (CI) 1.15–1.57] and two or more HIMs (aOR 1.48, 95% CI 1.22–1.78) especially in combination with thiazide diuretics increased the likelihood of severe hyponatraemia recurrence.

Conclusions

Prevalent use of HIMs after treatment for symptomatic or severe hyponatraemia and multiple HIM use increase the risk of recurrent hyponatraemia in geriatric patients.
Haploinsufficiency of TANK-binding kinase 1 prepones age-associated neuroinflammatory changes without causing motor neuron degeneration in aged mice
Authors: Bruno Clara , Sieverding Kirsten , Freischmidt Axel , Satoh Takashi , Walther Paul , Mayer B , Ludolph Albert C , Akira Shizuo , Yilmazer-Hanke Deniz , Danzer Karin M , Lobsiger Christian S , Brenner David , Weishaupt Jochen H
Published: August 2020

Loss-of-function mutations in TANK-binding kinase 1 cause genetic amyotrophic lateral sclerosis and frontotemporal dementia. Consistent with incomplete penetrance in humans, haploinsufficiency of TANK-binding kinase 1 did not cause motor symptoms in mice up to 7 months of age in a previous study. Ageing is the strongest risk factor for neurodegenerative diseases. Hypothesizing that age-dependent processes together with haploinsufficiency of TANK-binding kinase 1 could create a double hit situation that may trigger neurodegeneration, we examined mice with hemizygous deletion of Tbk1 (Tbk1+/− mice) and wild-type siblings up to 22 months. Compared to 4-month old mice, aged, 22-month old mice showed glial activation, deposition of motoneuronal p62 aggregates, muscular denervation and profound transcriptomic alterations in a set of 800 immune-related genes upon ageing. However, we did not observe differences regarding these measures between aged Tbk1+/− and wild-type siblings. High age did also not precipitate TAR DNA-binding protein 43 aggregation, neurodegeneration or a neurological phenotype in Tbk1+/− mice. In young Tbk1+/− mice, however, we found the CNS immune gene expression pattern shifted towards the age-dependent immune system dysregulation observed in old mice. Conclusively, ageing is not sufficient to precipitate an amyotrophic lateral sclerosis or frontotemporal dementia phenotype or spinal or cortical neurodegeneration in a model of Tbk1 haploinsufficiency. We hypothesize that the consequences of Tbk1 haploinsufficiency may be highly context-dependent and require a specific synergistic stress stimulus to be uncovered.
Effects of Age on Prestimulus Neural Activity Predictive of Successful Memory Encoding: An fMRI Study
Authors: Liu E Song , Koen Joshua D , Rugg Michael D
Published: August 2020

Prestimulus subsequent memory effects (SMEs)—differences in neural activity preceding the onset of study items that are predictive of later memory performance—have consistently been reported in young adults. The present functional magnetic resonance imaging experiment investigated potential age-related differences in prestimulus SMEs. During study, healthy young and older participants made one of two semantic judgments on images, with the judgment signaled by a preceding cue. In test phase, participants first made an item recognition judgment and, for each item judged old, a source memory judgment. Age-invariant prestimulus SMEs were observed in left dorsomedial prefrontal cortex, left hippocampus, and right subgenual cortex. In each case, the effects reflected lower blood oxygen level dependent signal for later recognized items, regardless of source accuracy, than for unrecognized items. A similar age-invariant pattern was observed in left orbitofrontal cortex, but this effect was specific to items attracting a correct source response compared to unrecognized items. In contrast, the left angular gyrus and fusiform cortex demonstrated negative prestimulus SMEs that were exclusive to young participants. The findings indicate that age differences in prestimulus SMEs are regionally specific and suggest that prestimulus SMEs reflect multiple cognitive processes, only some of which are vulnerable to advancing age.
Imaging a Fever—Redefining the Role of 2-deoxy-2-[18F]Fluoro-D-Glucose–Positron Emission Tomography/Computed Tomography in Fever of Unknown Origin Investigations
Authors: Wright William F , Auwaerter Paul G , Dibble Elizabeth H , Rowe Steven P , Mackowiak Philip A
Published: August 2020

Growing evidence suggests that 2-deoxy-2-[18F]fluoro-D-glucose (18FDG)–positron emission tomography/computed tomography (PET/CT) is a useful imaging technique for the evaluation of fever of unknown origin (FUO). This imaging technique allows for accurate localization of foci of hypermetabolism based on 18FDG uptake in glycolytically active cells that may represent inflammation, infection, or neoplasia. The presence of abnormal uptake can help direct further investigation that may yield a final diagnosis. A lack of abnormal uptake can be reasonably reassuring that these conditions are not present, thereby avoiding unnecessary additional testing. Insurers have not routinely covered outpatient 18FDG-PET/CT for the indication of FUO in the United States. However, data published since 2007 suggest early use in FUO diagnostic evaluations improves diagnostic efficiency and reduces costs. Clinicians and insurers should consider 18FDG-PET/CT as a useful tool when preliminary studies are unrevealing.
Modelling the impact of structural directionality on connectome-based models of neural activity
Authors: Padmore Amelia , Nelson Martin R , Chuzhanova Nadia , Crofts Jonathan J
Published: August 2020

Understanding structure--function relationships in the brain remains an important challenge in neuroscience. However, whilst structural brain networks are intrinsically directed, due to the prevalence of chemical synapses in the cortex, most studies in network neuroscience represent the brain as an undirected network. Here, we explore the role that directionality plays in shaping transition dynamics of functional brain states. Using a system of Hopfield neural elements with heterogeneous structural connectivity given by different species and parcellations (cat, Caenorhabditis elegans and two macaque networks), we investigate the effect of removing directionality of connections on brain capacity, which we quantify via its ability to store attractor states. In addition to determining large numbers of fixed-point attractor sets, we deploy the recently developed basin stability technique in order to assess the global stability of such brain states, which can be considered a proxy for network state robustness. Our study indicates that not only can directed network topology have a significant effect on the information capacity of connectome-based networks, but it can also impact significantly the domains of attraction of the aforementioned brain states. In particular, we find network modularity to be a key mechanism underlying the formation of neural activity patterns, and moreover, our results suggest that neglecting network directionality has the scope to eliminate states that correlate highly with the directed modular structure of the brain. A numerical analysis of the distribution of attractor states identified a small set of prototypical direction-dependent activity patterns that potentially constitute a `skeleton' of the non-stationary dynamics typically observed in the brain. This study thereby emphasizes the substantial role network directionality can have in shaping the brain's ability to both store and process information.
‘Non per instituir altri’? Attitudes to Rule-Following in Sixteenth-Century Poetics
Authors: Hetherington Michael
Published: August 2020

Literary historians tend to associate a poetics of rule-following with seventeenth-century neoclassicism, and with the sixteenth-century Italian commentators and theorists on whom the neoclassical critics drew; but thinking about the value and limitations of rules for writing is a pervasive and philosophically distinctive feature of pre-modern poetics more generally. Drawing on texts from different national literatures, on the literary theory of classical antiquity, on reflections on rule-following in non-literary early modern disciplines, and on some of the rich thinking on rules by modern philosophers, this article attempts to identify and describe some of the distinct kinds of rule-making and rule-following that constituted the discipline and practice of poetics in the sixteenth-century. To do so it focuses on three texts: Jodocus Badius Ascensius’ edition of Horace’s Ars poetica (1503), which divides the text up into ‘regulae’; Julius Caesar Scaliger’s Poetices libri septem (1561), which probes the ways in which ancient texts might function as ‘normae’ to which literary practice might be referred; and Samuel Daniels’ Musophilus (1599), which deeply if idiosyncratically meditates on the poet’s obligations and freedoms, and voices a profound scepticism about a literary practice that conforms to rules inherited from prior writers or imposed by critics.
The Mediatization of Human Rights Memory in Chile
Authors: Simón Salazar Harry
Published: August 2020

The current pandemic-imposed reliance on media-centered forms of civic engagement underscores the need for empirical mediatization research on the relationship between media, partisan conflict, and political culture. Drawing from critical Latin American media scholarship, mediatization theory, and Cultural Historical Activity Theory (CHAT), this article proposes a framework for comparative political communication research that centers on media practices and sociocultural change. By analyzing how a 1988 political advertising campaign in dictatorial Chile instantiated a peculiar vision of democratic transition, this article provides an examination of the disjuncture between televised representations of cheerful political reconciliation and abominable human rights abuses as the initial stage in the mediatization of Chilean human rights memory (HRM).
Percutaneous closure of an iatrogenic right ventricular perforation with an angio-seal vascular closure device: a case report
Authors: Coughlan J J , Szirt Richard , Pearson Ian , Cosgrave John
Published: August 2020

Background

Iatrogenic perforation of the right ventricle (RV) is a rare but recognized complication of pericardiocentesis. Treatment strategies for RV perforation include surgical repair and percutaneous closure. In this case report, we describe the use of an angio-seal vascular closure device (Terumo Interventional Systems) to seal an iatrogenic RV perforation secondary to incorrect placement of a pericardial drain.

Case summary

A 55-year-old female presented with an anterior ST-elevation myocardial infarction. Coronary angiography demonstrated occlusion of the left anterior descending artery. The patient went on to have primary percutaneous coronary intervention and both the left anterior descending and D1 were wired. During kissing balloon inflation, the Sion Blue wire migrated distally in the D1 causing an Ellis type 3 wire tip perforation in the distal D1. Emergency pericardiocentesis was performed however the 8 French (8 Fr) pericardial drain was inadvertently inserted into the RV. It was decided to attempt percutaneous closure with an 8 Fr angio-seal in the catheter lab under echocardiographic and fluoroscopic guidance. Our patient did not demonstrate any recurrence of pericardial effusion on repeat echocardiography over 60 days post-procedure.

Discussion

Our patient did not demonstrate any recurrence of pericardial effusion on repeat echocardiography over 60 days post-procedure. We feel that the angio-seal vascular closure device represents an effective, minimally invasive treatment for this rare but potentially catastrophic complication of pericardiocentesis. In this case, the technique spared our patient a sternotomy with its associated morbidity.
Measuring Exercise Capacity and Physical Function in Adult and Older Mice
Authors: Graber Ted G , Maroto Rosario , Fry Christopher S , Brightwell Camille R , Rasmussen Blake B
Published: August 2020

The inability of older adults to maintain independence is a consequence of sarcopenia and frailty. In order to identify the molecular mechanisms responsible for decreased physical function, it will be critical to utilize a small animal model. The main purpose of this study was to develop a composite Comprehensive Functional Assessment Battery (CFAB) of well-validated tests to determine physical function and exercise capacity in 3 age groups of male C57BL/6 mice (6 months old, n = 29; 24 months old, n = 24; 28+ months old, n = 28). To measure physical function in mice, we used rotarod (overall motor function), grip meter (forelimb strength), treadmill (endurance), inverted cling (strength/endurance), voluntary wheel running (volitional exercise and activity rate), and muscle performance with in vivo contractile physiology (dorsiflexor torque). We hypothesized that CFAB would be a valid means to assess the physical function of a given mouse across the life span. In addition, we proposed that CFAB could be used to determine relationships between different parameters associated with sarcopenia. We found that there was an overall age-related significant decline (p < .05) in all measurements, and the CFAB score demonstrated that some individual mice (the upper quartile) retained the functional capacity of average mice 1 cohort younger. We conclude that the CFAB is a powerful, repeatable, and noninvasive tool to assess and compare physical function and assess complex motor task ability in mice, which will enable researchers to easily track performance at the individual mouse level.
Quantifying model structural uncertainty using airborne electromagnetic data
Authors: Minsley Burke J , Foks Nathan Leon , Bedrosian Paul A
Published: August 2020

The ability to quantify structural uncertainty in geological models that incorporate geophysical data is affected by two primary sources of uncertainty: geophysical parameter uncertainty and uncertainty in the relationship between geophysical parameters and geological properties of interest. Here, we introduce an open-source, trans-dimensional Bayesian Markov chain Monte Carlo (McMC) algorithm GeoBIPy—Geophysical Bayesian Inference in Python—for robust uncertainty analysis of time-domain or frequency-domain airborne electromagnetic (AEM) data. The McMC algorithm provides a robust assessment of geophysical parameter uncertainty using a trans-dimensional approach that lets the AEM data inform the level of model complexity necessary by allowing the number of model layers itself to be an unknown parameter. Additional components of the Bayesian algorithm allow the user to solve for parameters such as data errors or corrections to the measured instrument height above ground. Probability distributions for a user-specified number of lithologic classes are developed through posterior clustering of McMC-derived resistivity models. Estimates of geological model structural uncertainty are thus obtained through the joint probability of geophysical parameter uncertainty and the uncertainty in the definition of each class. Examples of the implementation of this algorithm are presented for both time-domain and frequency-domain AEM data acquired in Nebraska, USA.
Olivine-induced viscous anisotropy in fossil strike-slip mantle shear zones and associated strain localization in the crust
Authors: Mameri Lucan , Tommasi Andréa , Signorelli Javier , Hassani Riad
Published: August 2020

We propose that strain localization in plate interiors, such as linear belts of intraplate seismicity, may arise from spatial variations in viscous anisotropy produced by preferred orientation of olivine crystals (CPO or texture) inherited from previous deformation episodes in the lithospheric mantle. To quantify this effect, we model the deformation of a plate containing a fossil strike-slip mantle shear zone at different orientations relative to an imposed horizontal shortening, but no initial heterogeneity in the crust. The fossil shear zone is characterized by different orientation and intensity of the olivine CPO relatively to the surrounding mantle, which is isotropic in most simulations. The anisotropy in viscosity produced by the CPO, which remains fixed throughout the simulations, is described by an anisotropic (Hill) yield function parametrized based on second-order viscoplastic self-consistent (SO-VPSC) models. The results indicate that lateral variations in viscous anisotropy in the mantle affect the strain distribution in the entire lithosphere. Reactivation of the strike-slip mantle shear zone and strain localization in the crust above it occur for horizontal compression at 35–55° to the fossil shear plane, with a maximum at 45°. The magnitude of strain localization depends on (i) the contrast in viscous anisotropy and, hence, on the variations in CPO orientation and intensity in the mantle, (ii) the boundary conditions and (iii) the feedbacks between mantle and crustal deformation. For a strong olivine CPO, when the boundary conditions do not hinder shear parallel to the fossil mantle shear zone, strain rates within it are up to a factor 30 higher than in an isotropic surrounding mantle or up to a factor 200 when the surrounding mantle is anisotropic, which results in strain rates up to a factor 10 or up to a factor 100 higher in the crust right above the fossil shear zone. Frictional weakening in the crust faults increases strain localization in the entire lithospheric column. High strength contrasts between the mantle and the ductile crust result in less efficient mechanical coupling, with strong localization in the mantle and lower crust, but weak in the brittle upper crust. Decrease in the crust–mantle strength contrast enhances the coupling and produces more homogenous strain distribution with depth, as well as a time-dependent evolution of strain localization, which reaches a peak and decreases before attaining steady-state. Comparison of seismic anisotropy, regional stress and focal mechanism data in linear arrays of intraplate seismicity, like the New Madrid and South Armorican seismic zones, to our models' predictions corroborates that olivine CPO preserved in fossil lithospheric-scale shear zones may be key for the development of such structures.
10. Defending a Claim
Authors: Macgregor Lucilla , Peacey Charlotte , Ridsdale Georgina
Published: August 2020

This chapter considers the options open to a defendant faced with a claim against him. It covers the emotional responses of the defendant, as well as the defendant’s pre-action position. It discusses the way in which a defendant may fund the litigation. It details the essential steps needed to respond to a claim; the substantive responses to the action; and tactical responses to the claim.
14. Interim Applications—Common Types
Authors: Macgregor Lucilla , Peacey Charlotte , Ridsdale Georgina
Published: August 2020

This chapter considers the interim applications that a legal representative may most often come across in practice. It looks at the procedure for the specific interim application. Then it discusses the form of the evidence needed to make or oppose it. The interim applications considered here include an application to set aside default judgment; summary judgment; interim payment; an application for specific disclosure; an application for security for costs; and an application for an injunction.
Development of Entrustable Professional Activities for Advanced Inflammatory Bowel Disease Fellowship Training in the United States
Authors: Cohen Benjamin L , Gallinger Zane R , Ha Christina , Holubar Stefan D , Hou Jason K , Kinnucan Jami , Mahadevan Uma , Moss Alan C , Raffals Laura E , Regueiro Miguel , Szigethy Eva , Wolf Douglas , Dubinsky Marla C , Patel Anish , Shah Brijen J , Ehrlich Orna G , Hanauer Stephen B
Published: August 2020

Background

The level of inflammatory bowel disease (IBD) training in general gastroenterology fellowship is often insufficient to prepare trainees to deliver advanced IBD care in practice. Advanced IBD fellowships have been developed to fill this training gap, but there is no established curriculum, and significant variability exists across programs. Entrustable professional activities (EPAs) are practical and realistic objectives that define essential tasks of a specialty that physicians should master to be competent during independent practice. The American College of Gastroenterology (ACG) and Crohn’s & Colitis Foundation (Foundation) established a task force to develop and appraise EPAs for advanced IBD fellowship.

Methods

Entrustable professional activities were developed using a multistep approach in a similar manner to other specialties. Initial EPAs identified via focus groups were evaluated, critiqued, and changed using an iterative model of feedback. The final EPAs were selected after the task force conducted a 3-phase modified Delphi method consisting of 2 sequential rounds of web-based voting and an in-person consensus meeting.

Results

Ten EPAs for advanced IBD fellowship were established including detailed descriptions with the associated knowledge, skills, and attitudes for each that can serve as curricular milestones.

Conclusion

Ten EPAs describing the core work of an advanced IBD fellowship–trained physician have been established by a multisociety task force. Creating EPAs for an advanced curriculum comes with unique challenges, particularly the need to prevent duplication of prior training competencies while demonstrating the potential for unique milestones.