bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal placement of shunt capacitor with VCPI to improve voltage profile using Mi power
Authors: Prasad Upendra , Sinha Nikhil Kumar , Rao Bathina Venkateswara , Lakshmi Naraharisetti Jaya Naga , Devarapalli Ramesh
Published: December 2020

Day to day the importance and usage of electric power is increasing, in order to reach this power demand, generation of power is being increased. But the transmission grid fails to meet the developments in generation, as construction of new transmission lines involve more time than building new generation facilities. So, updating or upgrading the existing facilities will be more beneficial than building new ones. This is achieved by providing proper reactive compensation. This main objective of the paper is placement of shunt capacitor for voltage profile improvement and reactive power compensation. The voltage stability index, called voltage collapse prediction index (VCPI), decides the shunt capacitor placement. This paper deals with placement of shunt capacitor banks to improve voltage at weakest buses. The shunt capacitor banks connected to the system to prevent the low voltages during the high loading conditions. The reactive compensation and reduction of losses and power transfer capability can be increased by placing of shunt capacitor. The proposed technique is validated with load flow analysis on IEEE 14 bus system carry out by Mi-power software. From the results obtained it is verified that the load flow analysis can be easily done with Mi-power which is a fast and robust tool with a powerful GUI to solve. Finally, the voltage profile improvement is verified with the placement of shunt capacitor.
THD analysis and design of filter combinations in 13 level cascaded H bridge with 1-phase half bridge LDN in multilevel inverter
Authors: ReddyK Rajeshwar , SathyavaniB  , Rajababu Durgam , Sanjay K
Published: December 2020

The study of total harmonic distortion is the important factor in power electronic devices for predominately calculations and it is effects the technical issues and cost functions. The 13 level Cascaded H bridge with 1-Phase half Bridge LDN networks improving for effectiveness of analysis in THD. This paper main objective is finding the harmonic analysis with different frequencies by using data sheets and MATLAB circuits learning process. The simulation results obtained using Cascaded H bridge with LDN method for producing the 13 level output related to different THD values with different frequencies changing the load parameter values. This system explains about differences between two methods and reducing the no of switches for developing same output values, but THD values are important for design of filter combinations in power electronic devices and it is changes at different frequencies with amplitude values.THDanalysed with SPWM method in multilevel inverter.
Electric vehicle technology: The transformation of conventional vehicle-based travel to an electric mobility in urban India
Authors: Irfan Md Mujahid , Deshmukh Ram , Teja M.S , Joshi Priyanka
Published: December 2020

The recent changes in the environment made the researchers to ideate new alternatives in all walks of life to reduce the effect of global warming and pollution. Transportation is one of the key factors for the day-day increase in the depletion of ozone layer. The conventional vehicles increase the air pollution by the emission of harmful gases, governments and people are now moving towards electrical mobility which is green and safe alternative. The drastic demand of electric vehicles inspired the researchers to bring new concepts into market which are user friendly and sustainable in nature. This paper deals with the comparison of various motor and battery technologies used by current automobile Electric Vehicle industry. The paper also presents the modelling and simulation of an electric car and recommends the common people to shift from conventional to electric vehicles.
Implementation of LDN to MLI and RSC-MLI configurations with a simple carrier-based modulation
Authors: Sathyavani B , Tara Kalyani S
Published: December 2020

The design of multilevel inverters (MLI) and reduced switch count (RSC) MLIs majorly depend on the requirements of desired output voltage levels, number of dc sources switching devices, and their ratings. With regard to these requirements ‘Level Doubling Network (LDN)’ configuration is introduced. LDN has the ability to double the output voltage levels of any MLI or RSC-MLI, preserving inverter modularity. However, the implementation of LDN to MLI or RSC-MLI is not unified and varies with switching operations. Thus, this work presents the implementation of LDN to popular MLI and RSC-MLI configurations and further presents a brief comparison on theswitch count, number of levels, and harmonic performance for both LDN and non-LDN cases. Further, a generalized carrier-based PWM scheme is presented to implement the LDN for any MLI and RSC-MLI configurations irrespective of voltage levels, dc-voltage ratios, and topological configuration. The performance of the inverter and the proposed modulation scheme are validated on MATLAB/Simulink environment.
Performance advancements of fuzzy controllers over conventional controllers carried out in matlab simulation environment
Authors: Shashi Kumar Reddy R , R Subrahmanyam K B V S , Venu Gopal D , Mahender K.
Published: December 2020

In this paper, we are used routine three term PID controller, fuzzy PID controller and FPI plus FPD controllers to test the performance characteristics of DC servo motor, modulus non-linear systems and square root nonlinear systems in MATLAB SIMULINK environment. We have developed analytical structures for fuzzy PID and FPI plus FPD controllers with the help of fuzzification, knowledge rule base and defuzzification methods. Simulation results are carried out and show the advancement of fuzzy controllers over conventional controllers in specificatons of rise time, delay time and settling time for DC servo motor, modulus and square root types of non-linear systems. Out of these three types of controllers, the experimental results conclude that the combination of FPI plus FPD controller gives the better results.
An Integration of dual UPQC controller for power quality compensation by extending its voltage regulation at grid side as a STATCOM
Authors: Teja M. S. , Reddy Ravula Shashi Kumar , Sudhakar AVV , Srinivas K.
Published: December 2020

This paper presents a modified controller by integrating dual unified power quality conditioners: iUPQC controller with its utilization in microgrid and power-quality utilizations. By applying this regulatory controller it extends the quality of power characteristics just like the UPQC controller it offers reactive power regulation both at load-side bus voltage and at grid-side bus voltage, which also compensates voltage swell & sag. At grid-side iUPQC controller will work as a STATCOM, by providing all the conventional UPQC applications both at the grid-side and load-side. Simulink consequences are providing to validate the latest predictability of the apparatus.

Index Terms: Dual topology: iUPQC, unified power quality conditioner (UPQC), power quality, micro grids, STATCOM-static synchronous compensator.
RETRACTED: IoT-based Flood Monitoring and Alerting System using Raspberry Pi
Authors: Subramanya Chari K , Thirupathi Maturi , Hariveena . Ch
Published: December 2020

The loss of properties and living population is getting enhanced by every year due to the dynamic alterations in weather conditions which results in heavy floods. Therefore, implementation of an intelligent analysis of flood risk is necessitated for the field of research in Disaster management. This article implements an intelligent IoT-based flood monitoring and alerting system using Raspberry Pi model, where water sensors and rain sensors are utilized to alert the authorities regarding the heaviness of rain and monitoring of water level in a lake or river. This system alerts the people in nearby villages since it utilizes IoT system for notifying the village people.
IoT based Child Safety Management using Raspberry Pi and RFID Technology
Authors: Jabirullah Mohammad , Amru M. , Raviteja D.
Published: December 2020

The protection and welfare of children is becoming more necessary to create a society that is greater and stronger. Therefore, the protection measures of kids must be strengthened to eliminate difficulties for kids. With this in mind, several tools and systems are employed to maintain the child’s safety environment. Improving intelligence agencies in this field, in this paper a system for children’s safety is proposedfor children safety purpose.We develop anIoT based child safety using raspberry. Students having a RFID based cards which used for authentication.Whenever student enters in school bus the Raspberry sends a message notification to parents and the principal.
RETRACTED: IoT-based Health Monitoring System with Medicine Remainder using Raspberry Pi
Authors: Amru M. , Mahesh Allam Venkata Naga , Ramesh Potharaju
Published: December 2020

In this busy rivalry-world, we can not persistently evaluate our elderly (mature persons) and patients, even though we love them too much. By using advancements in latest technologies, we build up this idea to save time and easy to understand. Our primary motive is to constantly monitor the health of the patient. In the execution of this proposal, we primarily have three separate modules: 1) wellbeing surveillance modules; 2) informants on ingestion of medicines; and 3) spokespersons.
Medical Image Fusion Based on Transformation Domain Approaches
Authors: Krishnamoorthi Raja , Bai Annapurna , Srinivas A.
Published: December 2020

Combining material from two or more images in a solo image is called a mixture of images and may preserve all the basic features of the first images. The key aim of the image mix is to produce an image that displays a desired scene or much higher than an image that provides a useful image to any essential characteristics. This approaches are the most essential for the detection and management of development in the fields of therapy. This article discusses the development and study of different algorithms, such as discrete transform wavelets (DWT), stationary transformation wavelets (SWT), fast and discrete transform curvelets (F-DCT) and transforming sampled dis-sub shapelets (DS-ST). Furthermore, fused picture quality has been measured with a number of efficiency indicators known as IQA.
Automatic Gas Leakage Detection using IOT
Authors: Dwibedi Rajat Kumar , Vanitha V. , Sagar R D , PhaniSai P , GanjikuntaYeshwanth
Published: December 2020

The gas detectors can be used for the detection of combustible, flammable and poisonous gases and for loss of oxygen, and also to detected a gas leak or other pollutants. It makes the area where the leak occurs an warning sound and instructs operators to leave the area. The system proposed is planned, built and sent an SMS warning system for detection of gas leakages. Infrared imaging sensors have recently been used for a number of applications in industrial plants and refineries.
Traffic Clearance System For Life Caution
Authors: Balamurugan S. , Annerose M , Bhuvaneswari P , Keerthika MS
Published: December 2020

Ambulances are utilized to save people’s lives in time. Emergency care can be administered only in the hospital if there are any complications in the traffic congestions. Because of poor facility in the ambulance, there is a possibility for patients to loss their life. Government of India has introduced a service for ambulances called 108. This 108 service is used to admit patients to the nearest hospital. It may take hours to clear the entire traffic and, in the meantime, the situation of the patient become worse. Suitable methodology is proposed for achieving the better results in safeguarding the public lives by increasing the transportation efficiency.
Fault Clearance Ultra Sensing Electronic Circuit Breaker
Authors: Ganesan M , Balamurugan S
Published: December 2020

As Electrical equipments are more sensible, it has to protect them from high current, short circuit occurance. For tripping, fuse, relays and circuit breakers are employed to safeguard the power system components and circuits as well. Due to existence of sensitive components, much attention is taken to care about the protecting system. This paper explains the protection of equipments using suitable circuit breaker. Ultra fast acting electronic circuit breaker(UFECB) is designed to act as an over current protection device. Circuit breakers like fuse or miniature breakers are preferred for breaking the circuit once short circuit is occurred. In case, when overload fault occurs, the time of tripping is slow and which depends on percentage of overload. For instant fault clearance, tripping mechanism is activated for sensitive loads[1]. Time taken for the tripping mechanism is also considered in a great manner for breaking and making the circuit at short instant.
Behaviour Of Self Compacted Concrete Produced With Steel Fiber, Glass fiber and Polypropylene Fiber Additives Subjected To High Temperature
Authors: Venkadachalam Gokulnath , DileepKumar M.
Published: December 2020

The paper introduces an examination concerning the productivity of temperature-delicate self-compacting concrete. Inspecting on self-compected solid, steel fiber, glass fiber, Poly propylene fiber to this end, addıng strands (steel fiber glassfiber, Polypropylene), using rivers and content 1.2% for blend of solid material When the shape tests were 7, 14,28 days old. They have been warmed to high temperatures. Every example were warmed to various temperatures for each solid blend (0°C,100C,200°C)Then, Tests for weight reduction and compressive quality were performed. The Observations of surface breaks were made after presentation to high temperatures Acritical loss of solidarityforallcementsafter200°C was watched, Especially for concrete containing Polypropylene fiber, glass fiber, steel fiber. The strands decreased the danger of dangerous spalling and forestalled it Based on the consequences of the investigation, the yield offine total cement can be induced.
E-Brainstorming Engenders Synergy Based on Ontology
Authors: Victor Akila , Aarthy S. L. , Sujatha R. , Srivani A.
Published: December 2020

The E-brainstorming system involves piggy bagging of ideas which results in more idea generation by the agents.Triggering of an idea for one participants happens from another participants, which will help the participants with the new idea. But with ordinary search and retrieval methods only few ideas are generated when compared with E-brainstorming method. More agents’ participation in E-brainstorming results in more ideas generation. The effect of combined participation of two or more agents is more than the sum of the effect of individual agents. The main goal of the project is to build an E-Brainstorming system where the agents represent the session participants and to build a idea evaluation system which is not domain specific. The E-brainstorming system is built so that it can be used both by the facilitator and the ordinary user who don’t have knowledge about the domain. The input idea given to the system is a sentence and the system solves the problem of input idea being a simple keyword or term.
Klann Mechanism
Authors: Manikanta Komma Siva , Vinodh Dr. , Silvister Raju Mr. John
Published: December 2020

The main objective is to design a spider mechanism by usingklann mechanism. Therefore, klann mechanism can access to places where the wheels cannot be used and it is even capable to travel any terrain and harmful places where the people can not work or travel like nuclear plants mining etc. now we are trying to obtain a klann mechanism robot which has both the motions in it like walking and climb over obstacle when it is needed by adjusting or changing the dimensions or the angles in the klann mechanism lay out. Its like we want to merge the both trajectory of walking and climbing into one trajectory so it can per from both the motions in needed.
Mathematical Modeling of alloy wheel rim shape optimization using metaheuristic method
Authors: Rahul Mattakoyya , Jaya Prakash Dr.J.
Published: December 2020

For the all automobile, wheel rim is very important part to control it. The wheel rims are only contact with both dynamic load and impact load. Dynamic load is rotation and the impact load is comes from road condition like speed breakers. Since we try alloy materials to the wheel rim. This alloy wheels are more safety and lighter than the other materials. In this paper, the alloy wheel rim is shape analyzed by the metaheuristic method using ansys workbench software. By using solidworks the 3d model of the wheel rim made. Based on the final deformation of all materials, the best material is selected.
Numerical Modelling and Experimental Analysis of Cracking Properties of Aluminium alloy
Authors: Srinivasrao G. , Jayaprakash J.
Published: December 2020

This paper describes the aluminium alloy mechanical properties during the impact loading. The full work focused on aluminium alloy AW 5005 process perforation and tensile test. The numerical analysis and experimental investigations are carried out on the aluminium alloy AW 5005. From this, the aluminium Aw 5005 ballistic properties of the structure are find out. This experiment is done by the help of conical shape projectile. The wide range strain rates are calculated by the experimental and numerical investigation. It is known as failure criteria of the aluminium alloy Aw 5005. The failure criteria is find out by the optimization method functions. The both perforation test and tension results are from the numerical and experimental investigation are tabulated for comparison.
Slope Stability in Rainfall Induced Landslided Area In Tirumala Hills By-Geotechnical Investigation
Authors: Sumanth Reddy G. , Needhidasan Dr.S.
Published: December 2020

Landslides are the sudden events which results in loss of both human and environmental life. It mainly happens due to the rainfall occurred in soil instable areas. If the rainwater passes into the pores of soil in slope areas then the soil transforms as slurry or muddy and the runoff takes place along with soil. So landslide will occurs accordingly in hill down areas. The soil samples will be collected at five successive selected locations where the slide occurred. The slope stability of the soil in landslide area can be tested and Factor of safety will be calculated. If the factor of safety will be less than 1, then the soil will be susceptible for instability. If the FOS will be greater than 1, then the soil will be stable under saturated conditions. Generally landslides are common in Tirumala hills. This paper explains about the nature of soil and properties of land erupted soil in Tirumala ghat road.
An Important Afro-Asian Biological Control Agent, Chrysoperla zastrowi sillemi (Neuroptera: Chrysopidae), Invades the New World
Authors: Mandese Zoe , Taylor Katherine L , Duelli Peter , Gallou Adrien , Henry Charles S
Published: December 2020

Climates around the world are rapidly turning warmer and often drier. Agricultural approaches must change accordingly. One important global practice is commercial use of cryptic species of the Chrysoperla carnea-group of green lacewings to control arthropod pests. Recently, one highly drought-tolerant species, originally present only in the Old World, is suspected of expanding its range to some of the driest habitats in the New World. Here we examine putative specimens of this species, Chrysoperla zastrowi (Esben-Petersen, 1928), collected in the desert southwest of the United States, the parched northwest of Mexico, and Guatemala. Using species-specific vibrational duetting-song phenotypes, subtle morphological character states, and mitochondrial DNA sequences, we confirm that C. zastrowi is now a naturalized part of the lacewing fauna of the Americas, making it the only species of the carnea-group to have a truly global range. As such, we encourage its broader commercial use for pest control on irrigated agricultural systems in the hotter, drier regions of the world to which it is best adapted and within which it now appears to be fully naturalized. We briefly consider future range expansion of both subspecies of C. zastrowi, C. z. zastrowi, and C. z. sillemi, in response to continued global warming.
Igf3 is essential for ovary differentiation in zebrafish†
Authors: Xie Yuxin , Huang Duo , Chu Lianhe , Liu Yun , Sun Xiao , Li Jianzhen , Cheng Christopher H K
Published: December 2020

Zebrafish gonadal sexual differentiation is an important but poorly understood subject. Previously, we have identified a novel insulin-like growth factor (Igf) named insulin-like growth factor 3 (Igf3) in teleosts. The importance of Igf3 in oocyte maturation and ovulation has been recently demonstrated by us in zebrafish. In this study, we have further found the essential role of Igf3 in gonadal sexual differentiation of zebrafish. A differential expression pattern of igf3 between ovary and testis during sex differentiation (higher level in ovary than in testis) was found in zebrafish. An igf3 knockout zebrafish line was established using TALENs-mediated gene knockout technique. Intriguingly, all igf3 homozygous mutants were males due to the female-to-male sex reversal occurred during sex differentiation. Further analysis showed that Igf3 did not seem to affect the formation of so-called juvenile ovary and oocyte-like germ cells. Oocyte development was arrested at primary growth stage, and the ovary was gradually sex-reversed to testis before 60 day post fertilization (dpf). Such sex reversal was likely due to decreased germ cell proliferation by suppressing PI3K/Akt pathway in early ovaries of igf3 mutants. Estrogen is considered as a master regulator in fish sex differentiation. Here, we found that igf3 expression could be upregulated by estrogen in early stages of ovarian follicles as evidenced in in vitro treatment assays and cyp19a1a mutant zebrafish, and E2 failed to rescue the defects of igf3 mutants in ovarian development, suggesting that Igf3 may serve as a downstream factor of estrogen signaling in sex differentiation. Taken together, we demonstrated that Igf3 is essential for ovary differentiation in zebrafish.
Impact Indicators for Biodiversity Conservation Research: Measuring Influence within and beyond Academia
Authors: Lavery Tyrone H , Morgain Rachel , Fitzsimons James A , Fluin Jennie , Macgregor Nicholas A , Robinson Natasha M , Scheele Ben C , Selwood Katherine E , Spindler Rebecca , Vuong Holly , West Simon , Wintle Brendan A , Lindenmayer David B
Published: December 2020

Measuring, reporting, and forecasting research impact beyond academia has become increasingly important to demonstrate and understand real-world benefits. This is arguably most important in crisis disciplines such as medicine, environmental sustainability and biodiversity conservation, where application of new knowledge is urgently needed to improve health and environmental outcomes. Increasing focus on impact has prompted the development of theoretical guidance and practical tools tailored to a range of disciplines, but commensurate development of tools for conservation is still needed. In the present article, we review available tools for evaluating research impact applicable to conservation research. From these, and via a survey of conservation professionals, we compiled and ranked a list of 96 impact indicators useful for conservation science. Our indicators apply to a logic chain of inputs, processes, outputs, outcomes, and impacts. We suggest the list can act as a clear guide to realize and measure potential impacts from conservation research within and beyond academia.
Testing the fair process heuristic in a traffic stop context: Evidence from a factorial study with video vignettes
Authors: Solomon Starr J , Chenane Joselyne L
Published: December 2020

We explored whether distributive justice mediated the observed association between procedural justice and legitimacy, as well as cooperation with police. We distributed a 2 × 2 factorial survey to a national online sample of 560 adults. Participants were randomly assigned to view one video vignette of a traffic stop varying the components of procedural justice (decision-making and treatment quality). We used structural equation modelling to test the significance of direct and indirect effects. The results indicated that distributive justice fully mediated the effect of decision-making quality on each outcome and partially mediated the effect of treatment quality on trust and cooperation with police. Theoretical and policy implications are discussed.
Outpatient Antibiotic Prescribing Patterns for Adult End-Stage Renal Disease Patients in New York State
Authors: Coritsidis George N , Yaphe Sean , Rahkman Ilay , Lubowski Teresa , Munro Carly , Lee Ti- Kuang , Stern Aaron , Bhat Premila
Published: December 2020

Background

Infections are important complications of end-stage renal disease (ESRD) with few studies having investigated oral antibiotic use. Inappropriate antibiotic prescribing can contribute to multidrug-resistant organisms and Clostridioides difficile infections seen in ESRD. This study investigates antibiotic prescribing practices in ESRD across New York State (NYS).

Methods

Retrospective case-control study from 2016 to 2017 of NYS ESRD and non-ESRD patients analyzing Medicare part B billing codes, 7 days before and 3 days after part D claims. Frequencies of each infection, each antibiotic, dosages, and the antibiotics associated with infections were assessed using χ 2 analysis. A NYS small dialysis organization comprising approximately 2200 patients was also analyzed. Outcomes measured were the frequencies of infections and of each antibiotic prescribed. Incidence measures included antibiotics per 1000 and individuals receiving antibiotics per 1000.

Results

A total of 48 100 infections were treated in 35 369 ESRD patients and 2 544 443 infections treated in 3 777 314 non-ESRD patients. ESRD patients were younger, male, and African American. ESRD and non-ESRD patients receiving antibiotics was 520.29/1000 and 296.48/1000, respectively (P < .05). The prescription incidence was 1359.95/1000 ESRD vs 673.61/1000 non-ESRD patients. In 36%, trimethoprim-sulfamethoxazole dosage was elevated by current ESRD guidelines. Top infectious categories included nonspecific symptoms, skin, and respiratory for ESRD; and respiratory, nonspecific symptoms, and genitourinary in non-ESRD.

Conclusions

This study identifies issues with appropriate antibiotic usage stressing the importance of antibiotic education to nephrologist and nonnephrologist providers. It provides support for outpatient antibiotic stewardship programs.
Impact of Implementation of the Core Elements of Outpatient Antibiotic Stewardship Within Veterans Health Administration Emergency Departments and Primary Care Clinics on Antibiotic Prescribing and Patient Outcomes
Authors: Madaras-Kelly Karl , Hostler Christopher , Townsend Mary , Potter Emily M , Spivak Emily S , Hall Sarah K , Goetz Matthew Bidwell , Nevers McKenna , Ying Jian , Haaland Benjamin , Rovelsky Suzette A , Pontefract Benjamin , Fleming-Dutra Katherine , Hicks Lauri A , Samore Matthew H
Published: December 2020

Background

The Core Elements of Outpatient Antibiotic Stewardship provide a framework to improve antibiotic use. We report the impact of core elements implementation within Veterans Health Administration sites.

Methods

In this quasiexperimental controlled study, effects of an intervention targeting antibiotic prescription for uncomplicated acute respiratory tract infections (ARIs) were assessed. Outcomes included per-visit antibiotic prescribing, treatment appropriateness, ARI revisits, hospitalization, and ARI diagnostic changes over a 3-year pre-implementation period and 1-year post-implementation period. Logistic regression adjusted for covariates (odds ratio [OR], 95% confidence interval [CI]) and a difference-in-differences analysis compared outcomes between intervention and control sites.

Results

From 2014–2019, there were 16 712 and 51 275 patient visits within 10 intervention and 40 control sites, respectively. Antibiotic prescribing rates pre- and post-implementation within intervention sites were 59.7% and 41.5%, compared to 73.5% and 67.2% within control sites, respectively (difference-in-differences, P < .001). Intervention site pre- and post-implementation OR to receive appropriate therapy increased (OR, 1.67; 95% CI, 1.31–2.14), which remained unchanged within control sites (OR,1.04; 95% CI, .91–1.19). ARI-related return visits post-implementation (–1.3% vs –2.0%; difference-in-differences P = .76) were not different, but all-cause hospitalization was lower within intervention sites (–0.5% vs –0.2%; difference-in-differences P = .02). The OR to diagnose non-specific ARI compared with non-ARI diagnoses increased post-implementation forintervention (OR, 1.27; 95% CI, 1.21 –1.34) but not control (OR, 0.97; 95% CI, .94–1.01) sites.

Conclusions

Implementation of the core elements was associated with reduced antibiotic prescribing for RIs and a reduction in hospitalizations. Diagnostic coding changes were observed.
Blood biochemical status of deep-sea sharks following longline capture in the Gulf of Mexico
Authors: Prohaska Bianca K , Talwar Brendan S , Grubbs R Dean
Published: December 2020

Prior to the Deepwater Horizon (DWH) oil spill, little research effort was focused on studying deep-sea sharks in the Gulf of Mexico (GoM). While the biology of these fishes remains virtually unknown, they are routinely captured in commercial fisheries as bycatch. In the absence of basic biological data, and with the probability of post-release survival unknown for most species, effective management plans cannot be formulated, making populations highly susceptible to overfishing. Any potential detrimental effects of the DWH oil spill, which occurred at 1500 m deep, are also unknown. Following longline capture, we characterized the physiological blood biochemical parameters related to secondary stress and compared them among seven shark species occurring on the continental shelf edge and slope in the GoM at depths ranging from 200 to 2000 m. We also investigated the relationship between blood parameters and depth as well as proximity to the oil spill site. The deep-sea sharks examined here exhibited variability in blood chemistry associated with the secondary stress response, with values falling within published records for previously studied elasmobranchs. Results suggested that there is greater relative physiological stress in shallower-dwelling sharks as well as smaller-bodied sharks. Further, the rate of core temperature warming was fastest in smaller bodied sharks, which likely contributes to greater physiological stress. The core temperatures of the larger-bodied, deeper-dwelling species were not altered as drastically as the smaller-bodied sharks after being hauled to the surface. Any chronic physiological effects of the oil spill were not detectable as there were no relevant correlations between blood chemistry metrics and proximity to the DWH oil spill site.
Age-growth relationships, temperature sensitivity and palaeoclimate-archive potential of the threatened Altiplano cactusEchinopsis atacamensis
Authors: English N B , Dettman D L , Hua Q , Mendoza J M , Muir D , Hultine K R , Williams D G
Published: December 2020

The tall (>4 m), charismatic and threatened columnar cacti, pasacana [Echinopsis atacamensis (Vaupel) Friedrich & G.D. Rowley)], grows on the Bolivian Altiplano and provides environmental and economic value to these extremely cold, arid and high-elevation (~4000 m) ecosystems. Yet very little is known about their growth rates, ages, demography and climate sensitivity. Using radiocarbon in spine dating time series, we quantitatively estimate the growth rate (5.8 and 8.3 cm yr−1) and age of these cacti (up to 430 years). These data and our field measurements yield a survivorship curve that suggests precipitation on the Altiplano is important for this species’ recruitment. Our results also reveal a relationship between night-time temperatures on the Altiplano and the variation in oxygen isotope values in spines (δ18O). The annual δ18O minimums from 58 years of in-series spine tissue from pasacana on the Altiplano provides at least decadal proxy records of temperature (r = 0.58; P < 0.0001), and evidence suggests that there are longer records connecting modern Altiplano temperatures to sea-surface temperatures (SSTs) in the Atlantic Ocean. While the role of Atlantic SSTs on the South American Summer Monsoon (SASM) and precipitation on the Bolivian Altiplano is well described, the impact of SSTs on Altiplano temperatures is disputed. Understanding the modern impact of SSTs on temperature on the Altiplano is important to both understand the impact of future climate change on pasacana cactus and to understand past climate changes on the Altiplano. This is the best quantitative evidence to date of one of the oldest known cactus in the world, although there are likely many older cacti on the Altiplano, or elsewhere, that have not yet been sampled. Together with growth, isotope and age data, this information should lead to better management and conservation outcomes for this threatened species and the Altiplano ecosystem.
One size does not fit all: inter- and intraspecific variation in the swimming performance of contrasting freshwater fish
Authors: Jones Peter E , Svendsen Jon C , Börger Luca , Champneys Toby , Consuegra Sofia , Jones Joshua A H , Garcia de Leaniz Carlos
Published: December 2020

Artificial barriers cause widespread impacts on freshwater fish. Swimming performance is often used as the key metric in assessing fishes’ responses to river barriers. However, barrier mitigation is generally based on the swimming ability of salmonids and other strong swimmers because knowledge of swimming ability for most other freshwater fish is poor. Also, fish pass designs tend to adopt a ‘one size fits all’ approach because little is known about population or individual variability in swimming performance. Here, we assessed interspecific and intraspecific differences in the sustained swimming speed (Usus) of five freshwater fish with contrasting body sizes, morphologies and swimming modes: topmouth gudgeon, European minnow, stone loach, bullhead and brown trout. Significant Usus variation was identified at three organizational levels: species, populations and individual. Interspecific differences in Usus were as large as 64 cm s−1, upstream populations of brown trout showed mean Usus 27 cm s−1 higher than downstream populations, and species exhibited high individual variation (e.g. cv = 62% in European minnow). Sustained swimming speed (Usus) increased significantly with body size in topmouth gudgeon, European minnow and brown trout, but not in the two benthic species, bullhead and stone loach. Aerobic scope had a significant positive effect on Usus in European minnow, stone loach and brown trout. Sustained swimming speed (Usus) decreased with relative pectoral fin length in European minnow and brown trout, whereas body fineness was the best predictor in stone loach and bullhead. Hence, swimming performance correlated with a diverse range of traits that are rarely considered when predicting fish passage. Our study highlights the dangers of using species’ average swimming speeds and illustrates why a ‘one size fits all’ approach often fails to mitigate for barrier effects. We call for an evidence-based approach to barrier mitigation, one that recognizes natural variability at multiple hierarchical levels.
Assessing the post-release effects of capture, handling and placement of satellite telemetry devices on narwhal(Monodon monoceros)movement behaviour
Authors: Shuert Courtney R , Marcoux Marianne , Hussey Nigel E , Watt Cortney A , Auger-Méthé Marie
Published: December 2020

Animal-borne telemetry devices have become a popular and valuable means for studying the cryptic lives of cetaceans. Evaluating the effect of capture, handling and tagging procedures remains largely unassessed across species. Here, we examine the effect of capture, handling and tagging activities on an iconic Arctic cetacean, the narwhal (Monodon monoceros), which has previously been shown to exhibit an extreme response to extended capture and handling. Using accelerometry-derived metrics of behaviour, including activity level, energy expenditure and swimming activity, we quantify the post-release responses and time to recovery of 19 individuals following capture and tagging activities considering the intrinsic covariates of sex and individual size and the extrinsic covariates of handling time and presence of a ‘bolt-on’ satellite telemetry device. From accelerometer-derived behaviour, most narwhals appeared to return to mean baseline behaviour (recovery) within 24 hours after release, which was supported by longer-term measures of diving data. None of the covariates measured, however, had an effect on the time individuals took to recover following release. Using generalized additive models to describe changes in behaviour over time, we found handling time to be a significant predictor of activity levels, energy expenditure and swimming behaviour following release. Individuals held for the longest period (>40 min) were found to display the largest effect in behaviour immediately following release with respect to swimming behaviour and activity levels. We also found some support for relationships between activity levels, energy expenditure and swimming activity and two other covariates: sex and the attachment of a bolt-on configuration satellite tags. Our results indicate that narwhals recover relatively quickly following capture, handling and tagging procedures, but we suggest that researchers should minimize handling time and further investigation is needed on how to mitigate potential effects of bolt-on satellite tags in these sensitive species.
Seasonal Abundance and Infectivity ofPhilaenus spumarius(Hemiptera: Aphrophoridae), a Vector ofXylella fastidiosain California Vineyards
Authors: Beal Dylan J , Cooper Monica , Daugherty Matthew P , Purcell Alexander H , Almeida Rodrigo P P
Published: December 2020

The meadow spittlebug, Philaenus spumarius (Linnaeus) (Hemiptera: Aphrophoridae), is a vector of the plant pathogen Xylella fastidiosa; however, its role in recent outbreaks of Pierce’s disease of grapevine (PD) in California is unclear. While the phenology and ecology of P. spumarius can help determine its contributions to PD epidemics, both remain poorly described in the North Coast vineyards of California. We assessed the phenology of P. spumarius in the region. Spittlemasses were first observed in February or March, while the emergence of adult spittlebugs did not occur until April or May depending on the year. Analysis of sweep and trap data from 2016 to 2018 revealed significant effects of survey month, vineyard site, and year on adult abundance in sweep and trap surveys. Spittlebug adults were present in the vineyards from April until December, with the greatest number of adults by sweep net in May or June, whereas adults on traps peaked between July and November. Analysis of natural infectivity in groups of field-collected spittlebug adults showed significant difference in transmission rates among months. Spittlebugs successfully transmitted Xylella fastidiosa (Wells) (Xanthomonadales: Xanthomonadaceae) to potted grapevines between July and December. The greatest risk of X. fastidiosa transmission by P. spumarius was in December (60%) followed by October (30%). However, the infectivity patterns of the meadow spittlebug did not align with the historical paradigm of California North Coast PD. We discuss alternative hypotheses in which P. spumarius could play a role in the epidemiology of this disease.
Novel risk score for predicting recurrence of atrial fibrillation after the Cryo-Maze procedure
Authors: Kakuta Takashi , Fukushima Satsuki , Minami Kimito , Saito Tetsuya , Kawamoto Naonori , Tadokoro Naoki , Ikuta Ayumi , Kobayashi Junjiro , Fujita Tomoyuki
Published: December 2020

OBJECTIVES

This study aimed to develop a novel risk score model for quantitative prediction of the rate of atrial fibrillation (AF) recurrence after the Cryo-Maze procedure in patients with persistent AF.

METHODS

We enrolled 450 consecutive patients who underwent the Cryo-Maze procedure for persistent AF concomitant with other cardiac procedures in our institute between 2001 and 2019. We randomly divided the cohort into two groups. We derived a model in a ‘development cohort’ (270 patients; 60%) and validated it in a ‘test cohort’ (180 patients; 40%) by receiver operating characteristic curve analysis.

RESULTS

The median follow-up was 5.2 (interquartile range: 2.0–9.9) years. The 1-, 5-, 10- and 15-year rates of freedom from AF recurrence in the entire cohort were 91.4%, 83.5%, 76.2% and 57.1%, respectively. Risk factors for AF recurrence examined by logistic regression analysis included F-wave voltage in V1 < 0.2 mV, preoperative AF duration >5 years and left atrial volume index >100 ml/m2. Points were assigned to each risk factor according to its odds ratio. A novel risk score model was developed using these three variables and age, with a range up to 10 points. High score (>7) predicted high rates of AF recurrence after the Cryo-Maze procedure. The area under the receiver operating characteristic curve of the novel risk model score was 0.78 (95% confidence interval: 0.65–0.91) in the test cohort.

CONCLUSIONS

Use of the Cryo-Maze procedure should be carefully considered in patients with a higher model score because of a higher risk of AF recurrence.
Evolution of P-wave indices during long-term follow-up as markers of atrial substrate progression in arrhythmogenic right ventricular cardiomyopathy
Authors: Baturova Maria A , Svensson Anneli , Aneq Meriam Åström , Svendsen Jesper H , Risum Niels , Sherina Valeriia , Bundgaard Henning , Meurling Carl , Lundin Catarina , Carlson Jonas , Platonov Pyotr G
Published: December 2020

Aims

Patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) have increased prevalence of atrial arrhythmias indicating atrial involvement in the disease. We aimed to assess the long-term evolution of P-wave indices as electrocardiographic (ECG) markers of atrial substrate during ARVC progression.

Methods and results

We included 100 patients with a definite ARVC diagnosis according to 2010 Task Force criteria [34% females, median age 41 (inter-quartile range 30–55) years]. All available sinus rhythm ECGs (n = 1504) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. P-wave duration, P-wave area, P-wave frontal axis, and prevalence of abnormal P terminal force in lead V1 (aPTF-V1) were assessed and compared at ARVC diagnosis, 10 years before and up to 15 years after diagnosis.

Prior to ARVC diagnosis, none of the P-wave indices differed significantly from the data at ARVC diagnosis. After ascertainment of ARVC diagnosis, P-wave area in lead V1 decreased from −1 to −30 µV ms at 5 years (P = 0.002). P-wave area in lead V2 decreased from 82 µV ms at ARVC diagnosis to 42 µV ms 10 years after ARVC diagnosis (P = 0.006). The prevalence of aPTF-V1 increased from 5% at ARVC diagnosis to 18% by the 15th year of follow-up (P = 0.004). P-wave duration and frontal axis did not change during disease progression.

Conclusion

Initial ARVC progression was associated with P-wave flattening in right precordial leads and in later disease stages an increased prevalence of aPTF-V1 was seen.
Exploring the cause of conduction delays in patients with repaired Tetralogy of Fallot
Authors: Verzaal Nienke J , Massé Stéphane , Downar Eugene , Nanthakumar Kumaraswamy , Delhaas Tammo , Prinzen Frits W
Published: December 2020

Aims

Cardiac dyssynchrony in patients with repaired Tetralogy of Fallot (rToF) has been attributed to right bundle branch block (RBBB), fibrosis and/or the patches that are inserted during repair surgery. We aimed to investigate the basis of abnormal activation in rToF patients by mapping the electrical activation sequence during sinus rhythm (SR) and right ventricular (RV) pacing.

Methods and Results

A total of 17 patients were studied [13 with rToF, 2 with left bundle branch block (LBBB), and 2 without RBBB or LBBB (non-BBB)] during medically indicated cardiac surgery. During SR and RV pacing, measurements were performed using 112-electrode RV endocardial balloons (rToF only) and biventricular epicardial sock arrays (four of the rToF and all non-rToF patients). During SR, functional lines of block occurred in five rToF patients, while RV pacing caused functional blocks in four rToF patients. The line of block persisted during both SR and RV pacing in only 2 out of 13 rToF patients. Compared to SR, RV pacing increased dispersion of septal activation, but not dispersion of endocardial and epicardial activation of the RV free wall. During pacing, RV and left ventricular activation dispersion in rToF patients were comparable to that of the non-rToF patients.

Conclusion

The results of the present study indicate that the delayed activation in the right ventricle of rToF patients is predominantly due to block(s) in the Purkinje system and that conduction in RV tissue is fairly normal.
Cycle length statistics during human atrial fibrillation reveal refractory properties of the underlying substrate: a combined in silico and clinical test of concept study
Authors: Unger Laura A , Azzolin Luca , Nothstein Mark , Sánchez Jorge , Luik Armin , Seemann Gunnar , Yeshwant Srinath , Oesterlein Tobias , Dössel Olaf , Schmitt Claus , Spector Peter , Loewe Axel
Published: December 2020

Aims

The treatment of atrial fibrillation beyond pulmonary vein isolation has remained an unsolved challenge. Targeting regions identified by different substrate mapping approaches for ablation resulted in ambiguous outcomes. With the effective refractory period being a fundamental prerequisite for the maintenance of fibrillatory conduction, this study aims at estimating the effective refractory period with clinically available measurements.

Methods and results

A set of 240 simulations in a spherical model of the left atrium with varying model initialization, combination of cellular refractory properties, and size of a region of lowered effective refractory period was implemented to analyse the capabilities and limitations of cycle length mapping. The minimum observed cycle length and the 25% quantile were compared to the underlying effective refractory period. The density of phase singularities was used as a measure for the complexity of the excitation pattern. Finally, we employed the method in a clinical test of concept including five patients. Areas of lowered effective refractory period could be distinguished from their surroundings in simulated scenarios with successfully induced multi-wavelet re-entry. Larger areas and higher gradients in effective refractory period as well as complex activation patterns favour the method. The 25% quantile of cycle lengths in patients with persistent atrial fibrillation was found to range from 85 to 190 ms.

Conclusion

Cycle length mapping is capable of highlighting regions of pathologic refractory properties. In combination with complementary substrate mapping approaches, the method fosters confidence to enhance the treatment of atrial fibrillation beyond pulmonary vein isolation particularly in patients with complex activation patterns.