bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Decreasing Gas Turbine Flue Gas Temperature on The Performance of Muara Tawar Combined Cycle Power Plant
Authors: Muchlisin  , Darmawan Nastopo , Budi Setya
Published: March 2021

Muara Tawar combined cycle power plant consists of three gas turbines, three heat recovery steam generators and one steam turbine. An update of gas turbine blades in 2016 effected on decreasing gas turbine flue gas temperature by 8°C up to 20°C. This study aims to analyse the effect of decreasing gas turbine flue gas temperature on output power of steam turbine. The output power of steam turbines is simulated by using Cycle-Tempo software, based on combined cycle heat balance. Variations of decreasing gas turbine flue gas temperature are configured on three gas turbines, two gas turbines and one gas turbine. The result shows that every 2°C decrease in flue gas temperature of three gas turbines will decrease output power of steam turbines by 0.787%. Whereas if decrease in flue gas temperature of two gas turbines and one gas turbine will decrease output power of steam turbine by 0.532% and 0.267% respectively. Meanwhile, the simulation results show that the decrease in the output power of the steam turbine after update of the gas turbine blades, 72.8% is caused by a decrease in gas turbine flue gas temperature and 27.2% by other factors.
Gas Fuel Mixing to Reduce Elemental Sulfur Formations on Gas Regulating and Metering Stations in Muara Karang Steam Power Plant
Authors: Ericson F , Moulina R , Jayawardana P P
Published: March 2021

Muara Karang Steam Power Plant uses natural gas as a primary energy source. Gas supplied from three different suppliers, PHE, PGN, and NR. Each supplier has different gas quality because it sourced from different gas fields and processes. To feeds gas to the boiler in Unit 4 Muara Karang Steam Power Plant, it has gas regulating facilities to reduce the pressure of natural gas from 24 kg/cm2 to 4 kg/cm2. In 2019, Control Reducing Valve (CRV) opening climbs gradually although power output from Unit 4 is constant. Inspection of the strainer found that elemental sulfur formations occur, and a clogged strainer makes gas flow to the burner reduced. To compensate for elemental sulfur formation, a fuel mixing strategy was implemented. Before the fuel mixing strategy implemented, Unit 4 needs maintenance outage every three months with a CRV gas opening increase of 0.93%/day. After the fuel mixing strategy implemented, it needs maintenance outage every five months and CRV gas opening increase of 0.44%/day because elemental sulfur formation occurs slower. The fuel mixing strategy can save up to 11.7 billion rupiahs of outage cost.
A Study of Reducing Waste Heat Rejected By Condenser Using Thermoelectric Heat Pumps to Decrease Net Plant Heat Rate of Coal Fired Power Plant
Authors: Chandra Satriya Wibawa I G A , Yunus Qomarul Huda M , Wisyaldin M K
Published: March 2021

Paiton 1-2 subcritical coal-fired power plant applied coal switching program in order to can compete at Jawa-Bali electrical system. The calorific value of coal consumed is switched from 5200 kcal/kg to 4500 kcal/kg. As the result, it increases the net plant heat rate (NPHR) as well as the coal flow and produce more CO2 emissions. Increasing final feed water temperature can reduce NPHR because less heat needed to produce steam. One of promising method to increase feed water temperature is reusing wasted energy being rejected to environment through condenser. There is opportunity to reuse this waste heat by use of thermoelectric heat pumps (THPs). THPs convert electrical energy into thermal energy using Peltier effect. It can capture the heat released by condensation process and reused for increasing the feed water temperature, which can increase the cycle efficiency. Furthermore, it will reduce coal flow, decrease NPHR and aid the reduction of CO2 emissions. To maximize the energy recovery, a number of heat pumps can be used in series. This paper focused on finding the optimum number of heat pumps array. The expected feed water temperature rise gained from THPs arrangement is 19.81°C and potentially will contribute to 0.66% reduction on NPHR.
Repair of Cracked 150 MW High-Pressure Steam Turbine Rotor Coupling
Authors: Hapsoro A , Hanipa H , Grebinnyk K
Published: March 2021

A 150 MW high-pressure steam turbine rotor in Philippine experienced cracking in coupling area. The root cause of crack failure was investigated, and it was revealed that alignment setup design from original equipment manufacturer (OEM) contributed to the failure. The cracked coupling was restored by weld build up back to original dimension and new alignment target was recalculated and the result was counterchecked by finite element analysis (FEA) method to verify the stress level reduction.
CFD Modeling to Analyze Palm Shell Co-firing Percentage on Ketapang CFB Power Plant
Authors: Dian J , Saksono H D , Nugroho A
Published: March 2021

Biomass is one of the world’s greatest sustainable energy potentials. Utilization of biomass in the form of Co-firing coal fuel with biomass is one alternative to reduce the dependence of fossil fuels towards green power plant. This paper addresses Co-Firing modelling test results up to 50% biomass using palm kernel shell (palm kernel shell) in Ketapang Coal Fired Power Plant (CFPP) 2x10 MW. Ketapang CFPP has circulating fluidized bed (CFB) boiler. There are several advantages by using direct co-firing in CFB boiler: direct co-firing has the lowest investment cost, CFB has a wider range of biomass selection characteristics and characteristics than PC Boilers, CFB can process biomass materials with higher moisture content, etc. Result shown that the optimum percentage of palm kernel shell biomass use in the Ketapang Power Plant is 30% palm kernel shell. This is caused by the temperature value at 18 cm above the furnace bed and furnace exit gas temperature of 30% palm kernel shell which is not too much different from the temperature value at 18 cm above the bed furnace and furnace exit gas temperature of 0% palm kernel shell. This is also strengthened by the high value of the CO2 mass fraction in the 30% palm kernel shell mixture, which indicates that an ideal combustion.
Study of Economic Viability of Floating Photovoltaic Electric Power in Indonesia
Authors: Untoro A A , Gunawan T , Hidayanto B D , Perkasa F A , Wijaya A A
Published: March 2021

The government has already set target for utilisation of renewable energy to be achieved are at least 23% in 2025 and 31% in 2050. This study assesses the feasibility of the implementation utility scale Floating Solar PV in Indonesia based on technical and economic perspective. The analysis focused on the assessment of solar irradiation data, module efficiency to project electric production, followed by economic analysis on the parameter of the interest rate, debt to equity ratio, electric production, EPC Cost. In Indonesia, there is also incentives which are regulated to promote the infrastructure investment including renewable energy which are tax holiday, import tax exemption which can reduce the tariff. The investigation show that the effect the interest rate, debt to equity ratio, EPC Cost to the tariff and effect the incentive which are the tax holiday, import tax exemption to the tariff. which are evaluated for each area based on on assessment energy yield projection and dam identification to be compared to electrical generation cost (BPP Local and BPP National) where based on the simulation the electricity tariff of Floating Solar PV (4.9 – 5.8 cUSD/kWh) in each province is below the BPP
Effect of Rotational Speed on Microstructure and Optical Properties of Bismuth Ferrite Oxide (BiFeO3)
Authors: Iriani Y , Suryana R , Agustina E B
Published: March 2021

BiFeO3 films were deposited on quartz substrate using chemical solution deposition (CSD) and spin coating techniques with variations of rotational speed (1000 rpm, 2000 rpm, and 3000 rpm) and several films (4 layers and 8 layers). It characterized microstructure of films using X-Ray Diffraction (XRD), morphology, and cross-section using SEM and optical properties using UV-Vis. The results of characterization showed that an enhancement rotational speed causes the intensity of crystal field orientation to decrease, crystallite size, and crystallinity are the same. Surface morphology is getting smoother, flatter, lower porosity and the grain to be homogeneous with thinner thickness. Addition on the number of films causes higher intensity, crystallite size and crystallinity are the same. The film gets thicker, the morphology gets rough, and the boundaries between grains become clearer. Increasing the rotational speed and number of films causes the refractive index and extinction coefficient to be smaller. The light disperses measurement shows a linear relationship between photon energy and refractive index. Energy band gap generated between 2.2-2.5 eV.
Preliminary Investigation of NiO Anode for NCA/NiO Battery from Spent Catalyst Recovery
Authors: Nisa S S , Nurohmah A R , Yudha C S , Rahmawati M , Paramitha T , Widiyandari H , Dyartanti E R , Purwanto A
Published: March 2021

Spent nickel catalyst is the catalyst residue that has lost its catalytic function. Spent nickel catalyst contains Ni metal which is already high and environmentally hazardous. This problem can be solved by recovering the spent nickel catalyst as an anode and combined with lithium nickel cobalt oxide (NCA) as a cathode for lithium ion batteries. A study about it has never been conducted. The method used to treat the spent catalyst was acid leaching using 1 M citric acid and 4 M hydrochloric acid at 70-80°C for 2 hours, then continued with precipitation and thermal decomposition. Another method employed was direct sintering at 800°C for 12 hours. Material characterisation was carried out by X-Ray Diffraction (XRD), Atomic Absorption Spectrophotometry (AAS), Fourier Transform Infra-Red (FTIR), and X-Ray Fluorescence (XRF), while electrochemical performance was carried out by NEWARE Battery Analyzer and BTS software. The results of this study indicate that Ni can be recovered with hydrochloric acid as much as 15.387 gr higher than citric acid as much as 11.831 gr from 20 gr sample. The XRD pattern also indicates the presence of crystals NiO I and NiO II in the leached and sintered material. The results of acid leaching in the form of NiO I was perfectly formed, but NiO still has a little impurity. Electrochemical performance was tested with a cylindrical battery resulting in a discharge capacity of 37.210 mAh g−1.
Comparison of surface integrity, tool wear and chip morphology in CO2 cryogenic and dry milling of 304 stainless steel
Authors: Jabbaripour Behzad , Masouleh Hamid Souzani , Hadi Lavaei Salmasi M
Published: March 2021

In this study, dry and CO2 cryogenic milling conditions on 304 stainless steel is investigated. The cutting speeds of (60, 100, 140 m min−1), feed rates of (0.1, 0.13, 0.16 mm tooth−1) and axial depth of cuts of (0.5, 1, 1.5 mm) are considered in the L9 Taguchi array to design both dry and cryogenic slot milling tests. In cryogenic milling, defects in surface topography and tool wear (flank wear, built up edge and tool chipping) reduced significantly compared to dry machining conditions. Cryogenic milling improved the surface roughness from 4% to 71% compared to the corresponding dry conditions. In dry milling, more serrated chips and more discontinuities are seen in the lateral sides of the chips than cryogenic. In cryogenic compared to dry milling, the surface hardness of the workpiece decreased from at least 8% to a maximum of 12%. Also, the hardness of dry milling surface, increased from 43% to 102% compared to the bulk material. The maximum depth of hardening in cryogenic milling is 23% lower than that of dry condition. Increasing cutting parameters or dry machining will intensify the plastic deformation and compressing the microstructural grains adjacent to the machining surface, as in the deformed surface zone, the grain boundaries are indistinguishable. The maximum reduction in the thickness of the deformed layer was about 16% in the cryogenic milling compared to the corresponding dry condition. Considering XRD diagrams for dry and cryogenic milling compared to non-machined condition, no significant metallurgical phase transformation has occurred in the workpiece material.
Effects of new micro-pocketed bore surface topographies on the performance behaviours of aerodynamic journal bearing
Authors: Pattnayak M R , Pandey R K , Dutt J K
Published: March 2021

This paper presents the exploration for improving the static and dynamic performance behaviours of a self-acting rigid gas journal bearing employing some new conceived micro-depth pocketed surface topographies at the bore. The conceived micro-pockets comprise of relatively large size rectangular pocket having micro-depth at bearing bore in the converging zone followed by placing of different designs of sub-pockets at the trailing edge of the previous one in the direction of journal rotation. The form of equation achieved from Patir and Cheng’s model for the case of hydrodynamic lubrication regime and the related dynamic pressure equations have been solved using the finite volume method discretisation scheme followed by the solution of the algebraic equations using the Gauss-Seidel iterative method. The minimum film thickness, frictional force, side leakage, bearing dynamic coefficients, effective stiffness, effective damping, and critical mass parameters have been investigated with each new bore surface topography and compared with the performances of conventional aerodynamic journal bearing. Substantial improvements in both static and dynamic performances have been found with the new micro-pocketed bore surface topographies as compared to conventional one. Moreover, the established best bore design has produced significant increase (21%) in minimum film thickness, substantial reduction (12%) in coefficient of friction, and excellent improvement (170%) in the stability parameter (critical mass) as compared to the conventional case.
Embedding theorems for solvable groups
Authors: Roman’kov Vitaly
Published: March 2021

In this paper, we prove a series of results on group embeddings in groups with a small number of generators. We show that each finitely generated group

G
G

lying in a variety

M

{\mathcal M}

can be embedded in a

4
4

-generated group

H
∈

M

A

H \in {\mathcal M}{\mathcal A}

(

A

{\mathcal A}

means the variety of abelian groups). If

G
G

is a finite group, then

H
H

can also be found as a finite group. It follows, that any finitely generated (finite) solvable group

G
G

of the derived length

l
l

can be embedded in a

4
4

-generated (finite) solvable group

H
H

of length

l
+
1

l+1

. Thus, we answer the question of V. H. Mikaelian and A. Yu. Olshanskii. It is also shown that any countable group

G
∈

M

G\in {\mathcal M}

, such that the abelianization

G

a
b

G_{ab}

is a free abelian group, is embeddable in a

2
2

-generated group

H
∈

M

A

H\in {\mathcal M}{\mathcal A}

.
Existence and spectral instability of bounded spatially periodic traveling waves for scalar viscous balance laws
Authors: Álvarez Enrique , Plaza Ramón
Published: March 2021

This paper studies both existence and spectral stability properties of bounded spatially periodic traveling wave solutions to a large class of scalar viscous balance laws in one space dimension with a reaction function of monostable or Fisher-KPP type. Under suitable structural assumptions, it is shown that this class of equations underlies two families of periodic waves. The first family consists of small amplitude waves with finite fundamental period which emerge from a Hopf bifurcation around a critical value of the wave speed. The second family pertains to arbitrarily large period waves which arise from a homoclinic bifurcation and tend to a limiting traveling (homoclinic) pulse when their fundamental period tends to infinity. For both families, it is shown that the Floquet (continuous) spectrum of the linearization around the periodic waves intersects the unstable half plane of complex values with positive real part, a property known as spectral instability. For that purpose, in the case of small-amplitude waves it is proved that the spectrum of the linearized operator around the wave can be approximated by that of a constant coefficient operator around the zero solution and determined by a dispersion relation which intersects the unstable complex half plane. In the case of large period waves, we verify that the family satisfies the assumptions of the seminal result by Gardner (Spectral analysis of long wavelength periodic waves and applications, J. Reine Angew. Math. 491 (1997), 149–181) of convergence of periodic spectra in the infinite-period limit to that of the underlying homoclinic wave, which is unstable. A few examples are discussed.
Characterization of multilinear multipliers in terms of Sobolev space regularity
Authors: Grafakos Loukas , Park Bae Jun
Published: March 2021

We provide necessary and sufficient conditions for multilinear multiplier operators with symbols in

L
r

L^r

-based product-type Sobolev spaces uniformly over all annuli to be bounded from products of Hardy spaces to a Lebesgue space. We consider the case

1
>
r
≤
2

1>r\le 2

and we characterize boundedness in terms of inequalities relating the Lebesgue indices (or Hardy indices), the dimension, and the regularity and integrability indices of the Sobolev space. The case

r
>
2

r>2

cannot be handled by known techniques and remains open. Our result not only extends but also establishes the sharpness of previous results of Miyachi, Nguyen, Tomita, and the first author (see Grafakos, Miyachi, and Tomita [Canad. J. Math. 65 (2013), pp. 299-330]; Grafakos, Miyachi, Nguyen, and Tomita [J. Math. Soc. Japan 69 (2017), pp. 529-562]; Grafakos and Nguyen [Colloq. Math. 144 (2016), pp. 1-30]; and Miyachi and Tomita [Rev. Mat. Iberoamer. 29 (2013), pp. 495-530]), who only considered the case

r
=
2

r=2

.
Deception and detection: the use of technology in assessing witness credibility
Authors: Bradshaw Robert
Published: March 2021

Tribunals, like courts, have long grappled with differentiating truthful from untruthful witnesses. A number of cases before the Court of Arbitration for Sport have considered whether polygraph evidence is admissible as a means of verifying witness testimony, though tribunals have not reached any consensus. Now, authorities in several countries are trialling a new generation of ‘lie detectors’ using technologies such as eye tracking, artificial intelligence, and brain imaging. Proponents argue that these new technologies are more accurate and less subjective than existing polygraphs and that they can transform the nature of witness evidence. This article outlines the potential scope of lie-detecting technologies in arbitration and their promise to revolutionize tribunals’ evaluations of witness credibility. It considers objections to their usage, including reliability, machine bias and privacy, and the privilege against self-incrimination, and concludes that considerations of fairness and proportionality favour excluding lie-detector evidence.
Enhanced Recovery After Surgery Protocol With Ultrasound-Guided Regional Blocks in Outpatient Plastic Surgery Patients Leads to Decreased Opioid Prescriptions and Consumption
Authors: Straughan David M , Lindsey John T , McCarthy Michelle , Legendre Davey , Lindsey John T
Published: March 2021

Background

Opioids are a mainstay of pain management. To limit the use of opioids, enhanced recovery after surgery (ERAS) protocols implement multimodal approaches to treat postoperative pain.

Objectives

The aim of this paper was to be the first to assess the efficacy of an ERAS protocol for plastic surgery outpatients that includes ultrasound-guided, surgeon-led regional blocks.

Methods

A retrospective review of patients undergoing outpatient plastic surgery on an ERAS protocol was performed. These patients were compared to a well-matched group not on an ERAS protocol (pre-ERAS). Endpoints included the amounts of opioid, antinausea, and antispasmodic medication prescribed. ERAS patients were given a postoperative questionnaire to assess both pain levels (0-10) and opioid consumption. ERAS patients anticipated to have higher levels of pain received ultrasound-guided anesthetic blocks.

Results

There were 157 patients in the pre-ERAS group and 202 patients in the ERAS group. Patients in the pre-ERAS group were prescribed more opioid (332.3 vs 100.3 morphine milligram equivalents (MME)/patient; P < 0.001), antinausea (664 vs 16.3 mg of promethazine/patient; P < 0.001), and antispasmodic (401.3 vs 31.2 mg of cyclobenzaprine/patient; P < 0.001) medication. Patients on the ERAS protocol consumed an average total of 22.7 MME/patient postoperatively. Average pain scores in this group peaked at 5.32 on postoperative day 1 and then decreased significantly daily.

Conclusions

Implementation of an ERAS protocol for plastic surgery outpatients with utilization of ultrasound-guided regional anesthetic blocks is feasible and efficacious. The ability to significantly decrease prescribed opioids in this unique patient population is noteworthy.

Level of Evidence: 4
Characterization of 2 linear peptides without disulfide bridges from the venom of the spider Lycosa poonaensis (Lycosidae)
Authors: Megaly Alhussin M A , Yoshimoto Yusuke , Tsunoda Yugo , Miyashita Masahiro , Abdel-Wahab Mohammed , Nakagawa Yoshiaki , Miyagawa Hisashi
Published: March 2021

Spider venom is a complex mixture of bioactive components, in which peptides play an important role by showing neurotoxicity or cytotoxicity. Disulfide-rich peptides are major components in the venom, but linear peptides without disulfide bridges are also present and often show antimicrobial activity. In this study, we analyzed the venom of the spider Lycosa poonaensis (Lycosidae) to find novel antimicrobial peptides using mass spectrometry. The result revealed that 120 out of 401 detected components were nondisulfide-bridged peptides. From them, the sequence of 2 peptides (lyp2370 and lyp1987) were determined by MS/MS analysis. The biological activity test revealed that lyp2370 has only weak antibacterial activity. On the other hand, lyp1987, which is identical to M-lycotoxin-Ls3b from the Lycosa singoriensi venom, showed significant antibacterial activity. The weak activity of lyp2370 was found to be due to the presence of a Glu residue on the hydrophilic face of its amphipathic α-helical structure.
Persistent spectral hypergraph based machine learning (PSH-ML) for protein-ligand binding affinity prediction
Authors: Liu Xiang , Feng Huitao , Wu Jie , Xia Kelin
Published: March 2021

Molecular descriptors are essential to not only quantitative structure activity/property relationship (QSAR/QSPR) models, but also machine learning based chemical and biological data analysis. In this paper, we propose persistent spectral hypergraph (PSH) based molecular descriptors or fingerprints for the first time. Our PSH-based molecular descriptors are used in the characterization of molecular structures and interactions, and further combined with machine learning models, in particular gradient boosting tree (GBT), for protein-ligand binding affinity prediction. Different from traditional molecular descriptors, which are usually based on molecular graph models, a hypergraph-based topological representation is proposed for protein–ligand interaction characterization. Moreover, a filtration process is introduced to generate a series of nested hypergraphs in different scales. For each of these hypergraphs, its eigen spectrum information can be obtained from the corresponding (Hodge) Laplacain matrix. PSH studies the persistence and variation of the eigen spectrum of the nested hypergraphs during the filtration process. Molecular descriptors or fingerprints can be generated from persistent attributes, which are statistical or combinatorial functions of PSH, and combined with machine learning models, in particular, GBT. We test our PSH-GBT model on three most commonly used datasets, including PDBbind-2007, PDBbind-2013 and PDBbind-2016. Our results, for all these databases, are better than all existing machine learning models with traditional molecular descriptors, as far as we know.
Politics, Research Design, and the ‘Architecture’ of Criminal Careers Studies
Authors: Farrall Stephen
Published: March 2021

Criminal careers research is one of the bedrocks—if not the bedrock—of criminology. It remains a key focal point of criminological research and has embraced ideas and theories from sociology, psychology, psychiatry and urban and community studies. Despite the widening of the landscape of what might be termed ‘the criminological enterprise’ (to include victimology, prisons research, punishment, deterrence and environmental criminology), criminal careers (now differentiated into studies of onset, persistence and desistance) remains a key plank of criminology. This article critiques the research design of longitudinal studies of criminal careers, arguing that a key explanatory factor has been consistently overlooked in criminal careers research due, in part, to the research design of such studies. In focussing on the role of politically motivated changes to economic policies and the restructuring of the industrial base this produced, I empirically relate individual offending careers to politics in ways very few have done before. The article touches upon a series of suggestions for how empirical studies of criminal careers might be improved.
Impact of co-morbidity on reoperation or death within 90 days of surgery for oesophageal cancer
Authors: Cheng Z , Johar A , Gottlieb-Vedi E , Nilsson M , Lagergren J , Lagergren P
Published: March 2021

Background

The impact of preoperative co-morbidity on postoperative outcomes in patients with oesophageal cancer is uncertain. A population-based and nationwide cohort study was conducted to assess the influence of preoperative co-morbidity on the risk of reoperation or mortality within 90 days of surgery for oesophageal cancer.

Methods

This study enrolled 98 per cent of patients who had oesophageal cancer surgery between 1987 and 2015 in Sweden. Modified Poisson regression models provided risk ratios (RRs) with 95 per cent confidence intervals (c.i.) to estimate associations between co-morbidity and risk of reoperation or death within 90 days of oesophagectomy. The RRs were adjusted for age, sex, educational level, pathological tumour stage, neoadjuvant therapy, annual hospital volume, tumour histology and calendar period of surgery.

Results

Among 2576 patients, 446 (17.3 per cent) underwent reoperation or died within 90 days of oesophagectomy. Patients with a Charlson Co-morbidity Index (CCI) score of 2 or more had an increased risk of reoperation or death compared with those with a CCI score of 0 (RR 1.78, 95 per cent c.i. 1.44 to 2.20), and the risk increased on average by 27 per cent for each point increase of the CCI (RR 1.27, 1.18 to 1.37). The RR was increased in patients with pulmonary disease (RR 1.66, 1.36 to 2.04), cardiac disease (RR 1.37, 1.08 to 1.73), diabetes (RR 1.50, 1.14 to 1.99) and cerebral disease (RR 1.40, 1.06 to 1.85).

Conclusion

Co-morbidity in general, and pulmonary disease, cardiac disease, diabetes and cerebral disease in particular, increased the risk of reoperation or death within 90 days of oesophageal cancer surgery. This highlights the value of tailored patient selection, preoperative preparation and postoperative care.
Discriminatory ability of next-generation tau PET tracers for Alzheimer’s disease
Authors: Yap Steven Y , Frias Barbara , Wren Melissa C , Schöll Michael , Fox Nick C , Årstad Erik , Lashley Tammaryn , Sander Kerstin
Published: March 2021

A next generation of tau PET tracers for the imaging of Alzheimer’s disease and other dementias has recently been developed. Whilst the new compounds have now entered clinical studies, there is limited information available to assess their suitability for clinical applications. Head-to-head comparisons are urgently needed to understand differences in the radiotracer binding profiles. We characterized the binding of the tau tracers PI2620, RO948, MK6240 and JNJ067 in human post-mortem brain tissue from a cohort of 25 dementia cases and age-matched controls using quantitative phosphorimaging with tritium-labelled radiotracers in conjunction with phospho-tau specific immunohistochemistry. The four radiotracers depicted tau inclusions composed of paired helical filaments with high specificity, both in cases with Alzheimer’s disease and in primary tauopathy cases with concomitant Alzheimer’s disease pathology. In contrast, cortical binding to primary tauopathy in cases without paired helical filament tau was found to be within the range of age-matched controls. Off-target binding to monoamine oxidase B has been overcome, as demonstrated by heterologous blocking studies in basal ganglia tissue. The high variability of cortical tracer binding within the Alzheimer’s disease group followed the same pattern with each tracer, suggesting that all compounds are suited to differentiate Alzheimer’s disease from other dementias.
Proof Automation in the Theory of Finite Sets and Finite Set Relation Algebra
Authors: Cristiá Maximiliano , Katz Ricardo D , Rossi Gianfranco
Published: March 2021

$\{log\}$ (‘setlog’) is a satisfiability solver for formulas of the theory of finite sets and finite set relation algebra (FS&RA). As such, it can be used as an automated theorem prover for this theory. $\{log\}$ is able to automatically prove a number of FS&RA theorems, but not all of them. Nevertheless, we have observed that many theorems that $\{log\}$ cannot automatically prove can be divided into a few subgoals automatically dischargeable by $\{log\}$. The purpose of this work is to present a prototype interactive theorem prover (ITP), called $\{log\}$-ITP, providing evidence that a proper integration of $\{log\}$ into world-class ITP’s can deliver a great deal of proof automation concerning FS&RA. An empirical evaluation based on 210 theorems from the TPTP and Coq’s SSReflect libraries shows a noticeable reduction in the size and complexity of the proofs with respect to Coq.
Current progress in clinical, molecular, and genetic aspects of adult fibromuscular dysplasia
Authors: Persu Alexandre , Dobrowolski Piotr , Gornik Heather L , Olin Jeffrey W , Adlam David , Azizi Michel , Boutouyrie Pierre , Bruno Rosa Maria , Boulanger Marion , Demoulin Jean-Baptiste , Ganesh Santhi K , J. Guzik Tomasz , Januszewicz Magdalena , Kovacic Jason C , Kruk Mariusz , de Leeuw Peter , Loeys Bart L , Pappaccogli Marco , Perik Melanie H A M , Touzé Emmanuel , Van der Niepen Patricia , Van Twist Daan J L , Warchoł-Celińska Ewa , Prejbisz Aleksander , Januszewicz Andrzej
Published: March 2021

Fibromuscular dysplasia (FMD) is a non-atherosclerotic vascular disease that may involve medium-sized muscular arteries throughout the body. The majority of FMD patients are women. Although a variety of genetic, mechanical, and hormonal factors play a role in the pathogenesis of FMD, overall, its cause remains poorly understood. It is probable that the pathogenesis of FMD is linked to a combination of genetic and environmental factors. Extensive studies have correlated the arterial lesions of FMD to histopathological findings of arterial fibrosis, cellular hyperplasia, and distortion of the abnormal architecture of the arterial wall. More recently, the vascular phenotype of lesions associated with FMD has been expanded to include arterial aneurysms, dissections, and tortuosity. However, in the absence of a string-of-beads or focal stenosis, these lesions do not suffice to establish the diagnosis. While FMD most commonly involves renal and cerebrovascular arteries, involvement of most arteries throughout the body has been reported. Increasing evidence highlights that FMD is a systemic arterial disease and that subclinical alterations can be found in non-affected arterial segments. Recent significant progress in FMD-related research has led to improve our understanding of the disease’s clinical manifestations, natural history, epidemiology, and genetics. Ongoing work continues to focus on FMD genetics and proteomics, physiological effects of FMD on cardiovascular structure and function, and novel imaging modalities and blood-based biomarkers that can be used to identify subclinical FMD. It is also hoped that the next decade will bring the development of multi-centred and potentially international clinical trials to provide comparative effectiveness data to inform the optimal management of patients with FMD.
Stylet Probing Behavior of Two Bactericera (Hemiptera: Psylloidea: Triozidae) Species on Host and Nonhost Plants
Authors: Mustafa Tariq , Horton David R , Cooper W Rodney , Zack Richard S , Thinakaran Jenita , Karasev Alexander V , Munyaneza Joseph E
Published: March 2021

Understanding host use by psyllids (Hemiptera: Psylloidea) benefits from comparative studies of behavior on host and nonhost plant species. While most psyllid species develop on one or a few closely related plant species, some species are generalized enough to develop on species across plant families. We used electropenetography (EPG) technology to compare probing activities of an oligophagous psyllid (Bactericera cockerelli (Šulc)) and a host-specialized psyllid (Bactericera maculipennis) on two species of Solanaceae (potato, Solanum tuberosum L. and matrimony vine, Lycium barbarum L.) and two species of Convolvulaceae (field bindweed, Convolvulus arvensis L. and sweet potato, Ipomoea batatas). Bactericera cockerelli develops on all four species, albeit with longer development times on Convolvulaceae. Bactericera maculipennis develops only on Convolvulaceae. Bactericera cockerelli fed readily from phloem of all four species, but the likelihood of entering phloem and duration of time in phloem was reduced on suboptimal hosts (Convolvulaceae) relative to behavior on Solanaceae. We observed instances of cycling between bouts of phloem salivation and ingestion in assays of optimal (Solanaceae) hosts not observed on Convolvulaceae. The Convolvulaceae-specialized B. maculipennis (Crawford) failed to feed from phloem of nonhosts (Solanaceae). Both psyllid species readily ingested from xylem of all plant species, irrespective of host status. Our finding that phloem feeding by B. maculipennis did not occur on potato has implications for understanding epidemiology of phloem-limited psyllid-vectored plant pathogens. Our results also showed that EPG assays detect subtle variation in probing activities that assist in understanding host use by psyllids.
R&D Heterogeneity and the Impact of R&D Subsidies*
Authors: Galaasen Sigurd Mølster , Irarrazabal Alfonso
Published: March 2021

In this paper we study the determinants of R&D heterogeneity and the economic impact of R&D subsidies. We estimate a Schumpeterian growth model featuring firms with heterogeneous innovation efficiencies. The model fits well the R&D investment distribution, and the frequency and relative size of R&D performers. Using the model, we study the impact of a Norwegian R&D reform targeting firms with R&D spending below a certain threshold. The size-dependent subsidy increases aggregate R&D investment by 11.7%, but reduces growth and welfare. In contrast, a uniform subsidy stimulates investment, growth and welfare.
Ethnic minorities and COVID-19: examining whether excess risk is mediated through deprivation
Authors: Razieh Cameron , Zaccardi Francesco , Islam Nazrul , Gillies Clare L , V. Chudasama Yogini , Rowlands Alex , Kloecker David E , Davies Melanie J , Khunti Kamlesh , Yates Thomas
Published: March 2021

Background

People from South Asian and black minority ethnic groups are disproportionately affected by the COVID-19 pandemic. It is unknown whether deprivation mediates this excess ethnic risk.

Methods

We used UK Biobank with linked COVID-19 outcomes occurring between 16th March 2020 and 24th August 2020. A four-way decomposition mediation analysis was used to model the extent to which the excess risk of testing positive, severe disease and mortality for COVID-19 in South Asian and black individuals, relative to white individuals, would be eliminated if levels of high material deprivation were reduced within the population.

Results

We included 15 044 (53.0% women) South Asian and black and 392 786 (55.2% women) white individuals. There were 151 (1.0%) positive tests, 91 (0.6%) severe cases and 31 (0.2%) deaths due to COVID-19 in South Asian and black individuals compared with 1471 (0.4%), 895 (0.2%) and 313 (0.1%), respectively, in white individuals. Compared with white individuals, the relative risk of testing positive for COVID-19, developing severe disease and COVID-19 mortality in South Asian and black individuals were 2.73 (95% CI: 2.26, 3.19), 2.96 (2.31, 3.61) and 4.04 (2.54, 5.55), respectively. A hypothetical intervention moving the 25% most deprived in the population out of deprivation was modelled to eliminate between 40 and 50% of the excess risk of all COVID-19 outcomes in South Asian and black populations, whereas moving the 50% most deprived out of deprivation would eliminate over 80% of the excess risk of COVID-19 outcomes.

Conclusions

The excess risk of COVID-19 outcomes in South Asian and black communities could be substantially reduced with population level policies targeting material deprivation.
Ultra-conserved sequences in the genomes of highly diverse Anopheles mosquitoes, with implications for malaria vector control
Authors: O’Loughlin Samantha M , Forster Annie J , Fuchs Silke , Dottorini Tania , Nolan Tony , Crisanti Andrea , Burt Austin
Published: March 2021

DNA sequences that are exactly conserved over long evolutionary time scales have been observed in a variety of taxa. Such sequences are likely under strong functional constraint and they have been useful in the field of comparative genomics for identifying genome regions with regulatory function. A potential new application for these ultra-conserved elements (UCEs) has emerged in the development of gene drives to control mosquito populations. Many gene drives work by recognizing and inserting at a specific target sequence in the genome, often imposing a reproductive load as a consequence. They can therefore select for target sequence variants that provide resistance to the drive. Focusing on highly conserved, highly constrained sequences lowers the probability that variant, gene drive-resistant alleles can be tolerated. Here, we search for conserved sequences of 18 bp and over in an alignment of 21 Anopheles genomes, spanning an evolutionary timescale of 100 million years, and characterize the resulting sequences according to their location and function. Over 8000 UCEs were found across the alignment, with a maximum length of 164 bp. Length-corrected gene ontology analysis revealed that genes containing Anopheles UCEs were over-represented in categories with structural or nucleotide-binding functions. Known insect transcription factor binding sites were found in 48% of intergenic Anopheles UCEs. When we looked at the genome sequences of 1142 wild-caught mosquitoes, we found that 15% of the Anopheles UCEs contained no polymorphisms. Our list of Anopheles UCEs should provide a valuable starting point for the selection and testing of new targets for gene-drive modification in the mosquitoes that transmit malaria.
Policy exclusion or confusion? Perspectives on universal health coverage for migrants and refugees in South Africa
Authors: White Janine A , Rispel Laetitia C
Published: March 2021

Notwithstanding the promise of the inclusivity of universal health coverage (UHC), the integration of migrants and refugees into host countries’ health systems remains elusive and contested. In South Africa, there is insufficient scholarly attention on UHC, migrants and refugees, given the country’s strategic importance in Africa and the envisaged implementation of the National Health Insurance (NHI) system. In this paper, a social exclusion conceptual framework is used to explore whether South African legislation, health policies and perspectives or actions of health policy actors facilitate UHC for migrants and refugees or exacerbate their exclusion. We combined a review of legislation and policies since 1994, with semi-structured interviews with 18 key informants from government, academia, civil society organizations and a United Nations organization. We used thematic analysis to identify themes and sub-themes from the qualitative data.

The South African Constitution and the National Health Act facilitate UHC, while the Immigration Act and the 2019 NHI Bill make the legal status of migrants the most significant determinant of healthcare access. This legislative disjuncture is exacerbated by variations in content, interpretation and/or implementation of policies at the provincial level. Resource constraints in the public health sector contribute to the perceived dysfunctionality of the public healthcare system, which affects the financial classification, quality of care and access for all public sector patients. However, migrants and refugees bear the brunt of the reported dysfunctionality, in addition to experiences of medical xenophobia. These issues need to be addressed to ensure that South Africa’s quest for UHC expressed through the NHI system is realized.
Asset map in a Chilean Health Promoting University: ‘a strategy for revitalization’
Authors: Pérez-Wilson Patricia , Marcos-Marcos Jorge , Carrasco-Portiño Mercedes , Ruiz-Cantero María Teresa , Alvarez-Dardet Carlos
Published: March 2021

Health Promoting Universities (HPUs) are more likely to perform actions intended to change habits and increase personal empowerment, than they are to develop community actions. The objective of this research is to create an asset map to visualize collective actions in a Chilean HPU. A qualitative study, based on the ABCD model was conducted. There were 149 people, distributed into 48 semi-structured interviews and 14 focus groups, who participated in this study (students, employees, ex-students and retirees). An asset map was elaborated, identifying the contributions of residents, associations and organizations, local institutions, physical resources, economic assets and local culture and with a new category, ‘connecting assets’. These categories show the range of resources in a university. According to the participants, the questions on asset identification were a tool for reflection, and by giving their opinions and discovering or drawing attention to new resources, they gained a better understanding of the assets in the university. Several participants stated that these talks could generate a positive emotional environment, which boosted their wellbeing. There were gender- and group-based differences in how the assets were valued. Students stressed assets related to services and benefits from the institution, green areas, and collective spaces. Employees, retirees and ex-students emphasized assets related to belonging, identity and traditions. Men appreciated openness and privacy in physical spaces. Women highlighted assets related to the institution. The resulting map, displays a range of resources that can help the university develop new possibilities for comprehensive and collective actions that would revitalize the HPU strategy.
Indigenous Youth Mentorship Program: essential characteristics of a Canadian multi-site community-university partnership with Indigenous communities
Authors: Lopresti Sabrina , Willows Noreen D , Storey Kate E , McHugh Tara-Leigh F ,   IYMP National Team
Published: March 2021

The Indigenous Youth Mentorship Program (IYMP) is a peer-led health promotion program grounded in the teachings of Indigenous scholars. IYMP is delivered as a multi-sited community-university partnership (CUP) with Indigenous communities across Canada for elementary students. A local young adult health leader and high school youth mentors offer students healthy snacks, physical activity games, relationship building activities and traditional cultural teachings. IYMP aims to improve children’s health and wellbeing and empower Indigenous youth and communities. The purpose of this descriptive qualitative study was to describe the essential characteristics of this multi-sited CUP as perceived by the IYMP principal investigators (PIs). Key informant interviews were conducted with 5 IYMP PIs (2 Indigenous) and analysed using content analysis. The overarching theme was forming a community of practice (CoP), where people with a common interest share best practices as they interact regularly. Four sub-themes were shared interest for Indigenous health/wellbeing and social justice, relationships, mentorship and taking a decolonizing research approach. The IYMP CoP allowed mentorship to occur across regions. The essential characteristics that made the IYMP CUPs successful could be used to inform other multi-sited CUPs with Indigenous communities. Those with mutual interests in Indigenous health and partnership with Indigenous communities could consider forming a CoP. Within a newly formed CoP, relationships and mentorship can be developed through discussion and activities. It is imperative within the CoP to take a decolonizing approach to research and acknowledge the impact that colonial policies and practices have had on generations of Indigenous peoples.
New Dimensions for Animal Communication Networks:Space and Time
Authors: Reichert Michael S , Enriquez Maya S , Carlson Nora V
Published: March 2021

Synopsis

Communication is a social process and usually occurs in a network of signalers and receivers. While social network analysis has received enormous recent attention from animal behaviorists, there have been relatively few attempts to apply these techniques to communication networks. Communication networks have the potential to offer novel insights into social network studies, and yet are especially challenging subjects, largely because of their unique spatiotemporal characteristics. Namely, signals propagate through the environment, often dissociating from the body of the signaler, to influence receiver behavior. The speed of signal propagation and the signal’s active space will affect the congruence of communication networks and other types of social network; in extreme cases, the signal may persist and only first be detected long after the signaler has left the area. Other signals move more rapidly and over greater distances than the signaler could possibly move to reach receivers. We discuss the spatial and temporal consequences of signaling in networks and highlight the distinction between the physical location of the signaler and the spread of influence of its signals, the effects of signal modality and receiver sensitivity on communication network properties, the potential for feedbacks between network layers, and approaches to analyzing spatial and temporal change in communication networks in conjunction with other network layers.