bluuebunny/crossref_metadata_2025 huggingface dataset:
On Integrated Fluid Screening and Turbomachinery Design for Optimized Industrial Heat Pumps
Authors: Karaefe Renan Emre , Post Pascal , di Mare Francesca , Venzik Valerius , Wotzka Paul , Müller Dirk , Barta Riley B.
Published: November 2022

This work presents an approach to the contextual integration of fluid selection and compressor design for the cycle design of efficient industrial heat pumps. The vapor-compression cycle of an air-water heat pump operated at 42 °C source and 82 °C target temperature is investigated as a theoretical case study. An optimization study is performed, which includes the assessment of suitable refrigerants. Besides well-known single-component refrigerants, various binary mixtures are considered. The cycle optimization aims at simultaneously providing high cycle coefficient of performance and volumetric heating capacity. Cycle operation with the mixtures R-41/Trans-2-Butene (10, 90 mol%) and CO2/R-161 (40, 60 mol%) yields the highest values of these parameters, respectively. For further evaluation, centrifugal compressors operated with each of the two promising mixtures are designed with an in-house meanline program. In addition, the compressor design for the hydrochlorofluoro-olefin refrigerant R-1234ze(Z) is considered as a reference. All designs are reviewed with respect to cycle as well as compressor design criteria and the applied methodology will assist designers in identifying key decision variables. The comprehensive design assessment suggests that CO2/R-161 provides the best overall solution for an efficient cycle with a compact compressor design.
Experimental Validation of a Rotor-Bearings System Model for Tesla Turbines Resonances Prediction
Authors: Niccolini Marmont Du Haut Champ Carlo Alberto , Silvestri Paolo , Reggio Federico
Published: November 2022

The main task of the present paper is the development and the implementation of a suitable analytical model to correctly capture rolling bearing radial stiffness, particularly nearby the critical speeds of the investigated rotor-bearings system. In this paper, such bearing non-linear stiffness model is applied to air bladeless turbines (or Tesla turbines) high speed rotors, in order to assess their global rotordynamic behavior when they are mounted on hybrid ball bearings.

In order to properly investigate all the issues related to critical speeds identification, an adequate number of tests was performed by exploiting an experimental air Tesla turbine prototype located at TPG experimental facility of the University of Genoa. The correlation between experimentally detected flexural critical speeds and their numerical predictions is markedly conditioned by the correct identification of ball bearings dynamic characteristics; in particular, bearings stiffness effect may play a significant role in terms of rotor-bearings system natural frequencies and therefore it must be accurately assessed. Indeed, Tesla turbine rotor FE model previously employed for numerical modal analysis relies on rigid bearings assumption and therefore it does not account for bearings stiffness overall contribution, which may become crucial in case of “hard mounting” of rotor-bearings systems. Subsequently, high-speed air Tesla rotor is investigated by means of an enhanced FE model for numerical modal analysis within Ansys® environment, where ball bearings are modelled as springs whose stiffness is expressed according to non-linear analytic model implemented in Matlab®.

The obtained results in terms of rotor-bearings system modal analysis exhibit an improvement in experimental-numerical results correlation by relying on such ball bearing stiffness model; moreover, beam-based FE model critical speeds predictions are coherent with experimental evidence and with respect to the previously employed FE model based on solid elements it is characterized by lower computational time and it is more easily interpretable. Thus, such experimentally validated numerical model represents a reliable and easily adaptable tool for high-speed rotating machinery critical speeds prediction in practical industrial application cases.
Thermodynamic Assessment of the Conversion of a Typical CCGT Power Plant to a Fully E-Fuel Fired Unit
Authors: Rigault Jérôme , De Paepe Ward , Laget Hannes
Published: November 2022

With the increasing need for flexibility in the electricity grid, combined with longer periods of low electricity prices due to an oversupply of renewable electricity, alternative solutions which include the production of carbon-free fuels in combination with the use of combined cycle power plants, are identified as possible solution. These so-called Power-to-Gas-to-Power solutions (P2G2P), with hydrogen and ammonia as fuel, require further research to determine their feasibility. Within this scope, the European collaborative project FLEXnCONFU aims at providing an answer towards this feasibility. The specific project idea is to recover excess grid power to produce hydrogen through proton exchange membrane (PEM) water electrolysis. Then, this hydrogen could be stored directly, or it could be fed in an ammonia synthesis process. Finally, the decarbonised fuels (ammonia and/or hydrogen) are burned in the gas turbine to produce electricity with no greenhouse gases (GHG) emission. The aim of this paper is to evaluate the impact of P2G2P system integration in a power plant. Different concepts have been applied to an existing ENGIE plant, based in Belgium, with the idea of installing all the technologies (electrolysers, compressors and storage, as well as ammonia fabrication units) on the power plant site. Simulations show that a considerable production time is needed to operate the plant several hours using these e-fuels. Moreover, hydrogen storage requires an extremely huge footprint, hence it looks more reasonable to operate ammonia synthesis to store large quantities of decarbonised fuel, given the site space constraints. Additionally, Aspen plus models have been realised to evaluate the global efficiency of the P2G2P systems as well as the specific cooling requirements of the added technologies. The global efficiency for the P2H2P (with hydrogen) system is 32%. For the P2A2P (with pure ammonia) and P2A2H2P (part of the produced ammonia is cracked to recover hydrogen, feeding the combustion chamber of the CCGT with a blend of 70% NH3 and 30% H2) systems, this global efficiency is reduced respectively to 24% and 19%. From these results, it is thus apparent that there remain still several challenges that need to be overcome to make P2G2P an efficient way to decarbonise electricity production. These main challenges are: Increase the efficiency of the transformation processes to limit the energy losses; Enhance hydrogen storage technologies to limit the footprint or develop an efficient hydrogen distribution; Reduce the cost of P2G technologies and especially of PEM electrolyzers; Progress on decarbonised fuels combustion and specifically limit NOx emission for the NH3 firing configuration.
Conceptual Study of Thermally Coupled Micro Gas Turbines and High Temperature Heat Pumps for Trigeneration
Authors: Gollasch Jens Oliver , Agelidou Eleni , Henke Martin , Stathopoulos Panagiotis
Published: November 2022

In the context of climate change low-emission technologies need to be developed to cover the high thermal energy demand of the industrial sector. Because of the ongoing transition to renewable energy sources and their limited availability, combustion-based technologies will be required to support this transition. This paper presents fundamental, application-independent conceptual studies of thermally coupled micro gas turbines (MGT) and high temperature heat pumps (HTHP). The MGT provides electrical power to drive the compressor of the heat pump, while the heat of the exhaust flow is used as a heat source. This self-sufficient system is expected to provide high thermal output at temperature levels beyond available heat pump technology. In addition, low temperatures can be achieved for cooling processes. Within the scope of this study, several process architectures with different integration of heat sources are analyzed by performing thermodynamic cycle simulations. The results demonstrate attainable temperature levels and it can be shown that heat can be provided at temperatures above 300 °C. Cooling processes can be effectively integrated in some of the investigated cycle configurations so that temperatures below −30 °C can be reached. Thermal coupling enables high utilization rates of primary energy and values over 100% are possible. The present work provides the basis for future studies, which will take the economic feasibility in comparison with competing technologies into consideration.
Optimal Management of Reversible Heat Pump/ORC Carnot Batteries
Authors: Torricelli Noemi , Branchini Lisa , De Pascale Andrea , Dumont Olivier , Lemort Vincent
Published: November 2022

In the view of reducing the global greenhouse gas emissions it becomes fundamental to exploit the renewable energy sources at their maximum potential by developing effective strategies for their flexible use. Among the available solutions to realize these strategies are the electric energy storages including the innovative Pumped Thermal Energy Storage technology (included in the Carnot battery concept). This can become very interesting in these applications where different energy flows must be handled (both electric and thermal), thanks to the possibility of adding the contribution of a waste heat source, in a thermally integrated energy storage. However, despite the several advantages, the state-of-the-art still lacks experiments and investigation of efficient control strategy for the Carnot battery when inserted into the process. As original contribution to the current literature, this paper presents the off-design model of a reversible Organic Rankine Cycle (ORC)/Heat Pump (HP) Carnot battery configuration with the aim of employing it to simulate the performance of such system and discuss its optimal management when inserted into a generic process. An existing reversible HP/ORC kW-size prototype is considered as reference and its optimal control in both HP and ORC mode under different boundary conditions is assessed.
Energy and the University: The Role of Gas Turbines at US Universities and Strategies for Enhancing Energy Literacy
Authors: Winegardner Erica , Lemay Emma , Lynch Stephen , Thole Karen A. , O’Connor Jacqueline
Published: November 2022

Ambitious international decarbonization goals and growing demand for energy are two powerful mandates that set the agenda for the gas turbine industry for the next several decades. To meet these goals and needs, educators must focus on the development of not only technical skills, but also energy literacy. Energy literacy has three components — the cognitive (awareness of energy concepts and technologies), the affective (awareness of the interaction between energy and greater societal issues), and the behavioral (agency to make energy-related decisions) — that can be significantly enhanced by not just curricular interventions, but also non-curricular activities. This paper begins by describing the energy landscape at Tier 1 Research (R1) Universities in the United States. Over 50% of R1 universities in the US use gas turbines to help meet their campus power and heating needs, and almost 60% of these universities have public facing information about campus energy production and usage, indicating an opportunity for enhancing energy literacy amongst the student body through better energy communication. Using these peer institutions as a backdrop, we focus on efforts by the Center for Gas Turbine Research, Education, and Outreach at the Pennsylvania State University as a case study to learn how to enhance energy literacy in engineers through both curricular and non-curricular interventions. The non-curricular intervention includes an energy dashboard, displayed in the student collaboration space for the Department of Mechanical Engineering, that shows real-time statistics on power and steam production, as well as gas turbine engine data from an advanced instrumentation package in one of the power stations on campus. The curricular intervention includes use of data from this dashboard in an introductory thermodynamics course, including the use of engine data in Brayton cycle analysis. In describing these efforts, we highlight the critical role that gas turbine technology and the gas turbine industry can play in enhancing the technical education and energy literacy of the future workforce.
The Pump-Turbine Selection Approach for Geomechanical Storage Facility
Authors: Patil Abhay , Hill Bunker , Wilkes Jason
Published: November 2022

The geo-mechanical hydro-storage method utilizes the natural energy storage capability of subsurface formations to store water under pressure. The pumps supply water underground and store it in-between layers of low permeability formations. The natural elasticity of the rock holds the water under pressure. The pressurized water is released through a turbine to produce electricity to send back to the grid. The proven capability to cycle hydraulic power across a broad range of geographies for long duration energy storage makes this method attractive. However, with the proposed pumped storage concept, the storage capacity and head availability requirements change as compared to conventional hydro storage facilities due to specific limitations with well-size (flow rate) and underground formation. The current study focuses on exploring different pump and turbine options for the given operating conditions and developing a way forward to qualify the pump and turbine for specific operational conditions based on cost, performance, and reliability. Pump options include centrifugal and plunger pumps, while turbine options include Pelton and Francis or Centrifugal Pump as Turbine. Three configurations are proposed based on initial cost and round-trip efficiency values. A metric Levelized Cost of Stored Energy (LCOSE) is utilized to compare the performance of different options, considering 25 years of overall life span. A sensitivity study was applied to chosen configurations and sizes for different roundtrip efficiencies and projected initial costs. Within given bounds, operational conditions, and assumptions made, the study outputs Pump-as-Turbine (PaT) as an optimal solution for the proposed conditions.
Dynamic Modelling of a Brayton PTES System
Authors: Frate Guido Francesco , Pettinari Matteo , Di Pino Incognito Emanuele , Costanzi Riccardo , Ferrari Lorenzo
Published: November 2022

The need for storage capacity is continuously increasing due to the progressive penetration of renewable energy sources in the power grids. New storage technologies for large-scale applications are emerging in this context, among which Pumped Thermal Electricity Storage (PTES) is a promising alternative. PTES is based on closed Brayton cycles: a Brayton heat pump is operated in the charging phase, using the off-peak electricity to transfer heat between two reservoirs. A Brayton heat engine is operated between the same reservoirs in the discharging phase, producing electric energy. The purpose of grid-scale storage facilities is to provide flexibility to the grid. Therefore, the proposed technologies must effectively operate in part-load conditions and quickly react when the load must be adjusted. In this study, the transient response of the Brayton PTES technology is studied, with particular emphasis on its off-design operation and control strategy. To this end, a detailed thermodynamic model of the system is developed. Particular attention is given to the sizing of the components relevant to the control. Furthermore, a control strategy suited for the power regulation of closed Brayton cycles, the Inventory Control, is investigated, and implementation is proposed. As it resulted, the system can operate in part-load with negligible performance degradation and is characterized by a rapid transient response. Therefore, Brayton PTES resulted as a promising storage technology for grid-scale applications.
Study to Adapt Industrial Gas Turbines for Significant and Viable CO2 Emissions Reduction
Authors: Burnes Daniel , Saxena Priyank , Kurz Rainer
Published: November 2022

Gas turbines have been a significant part of energy production and transportation for decades and should continue indefinitely. As the world evaluates the best approaches to achieve net-zero greenhouse gas emissions in the world by 2050, while also meeting energy demand, the industrial gas turbine will remain part of that solution with a variety of adaptations. Current (2021) global temperature rise from pre-industrial levels is at about 1.2°C and increasing at a significant rate. The Paris Agreement objective is to mitigate this rise to 1.5°C to stem climatic catastrophes and change. Adapting industrial gas turbines for lower CO2 emissions and carbon capture will be incentivized as the pricing authority on CO2 emissions will continue to increase throughout the world. Using the vast existing natural gas infrastructure, post combustion carbon capture to adapting to pure hydrogen or hydrogen / natural gas blends and other augmented solutions, will yield substantial GHG reductions could be implemented on industrial gas turbines. This paper presents the performance impact of adapting the industrial gas turbines for cost-effective carbon capture and using fuels with lower carbon content, such as hydrogen and hydrogen-natural gas blends. As a part of the discussion, the options of either transporting hydrogen to a power plant or transporting natural gas to said power plant and compressing and transporting captured CO2 back to a sequestration site, are evaluated, and supported with simulation data. Lastly, various configurations and mitigations that minimize carbon intensity are discussed and assessed through a simplified techno-economic analysis showing thresholds where industrial gas turbines remain viable in a clean energy future. Industrial gas turbines are needed for growing energy demand and to complement the growing deployment of clean and safe renewable energy sources.
An optical interface for quantum networks
Authors: Gangloff Dorian
Published: November 2022

A silicon atom embedded in diamond can be entangled with a photon
Reifying racism in medicine
Masters of Health: Racial Science and Slavery in U.S. Medical Schools
Christopher D. E. Willoughby
University of North Carolina Press, 2022. 282 pp.
Authors: Seth Suman
Published: November 2022

False beliefs about racial differences have a long history in physician training programs
Urban oasis
Authors: Popkin Gabriel
Published: November 2022

In Berlin, pioneering research into urban ecology has found surprising biodiversity in the city’s green spaces
A cleaner way to mine clean-energy mainstays
Authors: Normile Dennis
Published: November 2022

An electric field can reduce the need for polluting chemicals to extract rare earth elements
Immunological Control of HIV-1 Disease Progression by Rare Protective HLA Allele
Authors: Zhang Yu , Chikata Takayuki , Kuse Nozomi , Murakoshi Hayato , Gatanaga Hiroyuki , Oka Shinichi , Takiguchi Masafumi
Published: November 2022

HLA-B57 is a relatively rare allele around world and the strongest protective HLA allele in Caucasians and African black individuals infected with HIV-1. Previous studies suggested that the advantage of this allele in HIV-1 disease progression is due to a strong functional ability of HLA-B57-restricted Gag-specific T cells and lower fitness of mutant viruses selected by the T cells.
Enhanced Rishirilide Biosynthesis by a Rare In-Cluster Phosphopantetheinyl Transferase in Streptomyces xanthophaeus
Authors: Zhang Songya , Fan Shuai , Zhu Jing , Zhou Liying , Yan Xiaohui , Yang Zhaoyong , Si Tong , Liu Tao
Published: November 2022

Genome mining has been a vital means for natural product drug discovery in the postgenomic era. The rishirilide-type polyketides have attracted attention due to their potent bioactivity, but the poor robustness of production hosts has limited further research and development.
Status and future recommendations for recording and monitoring litter on the Arctic seafloor
Authors: Grøsvik Bjørn Einar , Buhl-Mortensen Lene , Bergmann Melanie , Booth Andy M. , Gomiero Alessio , Galgani Francois
Published: November 2022

Marine litter in the Arctic Basin is influenced by transport from Atlantic and Pacific waters. This highlights the need for harmonization of guidelines across regions. Monitoring can be used to assess temporal and spatial trends but can also be used to assess if environmental objectives are reached, for example, to evaluate the effectiveness of mitigation measures. Seafloor monitoring by trawling needs substantial resources and specific sampling strategies to be sufficiently robust to demonstrate changes over time. Observation and visual evaluation in shallow and deep waters using towed camera systems, remotely operated underwater vehicles, and submersibles are well suited for the Arctic environment. The use of imagery still needs to be adjusted through automation and image analyses, including deep learning approaches and data management, but will also serve to monitor areas with a rocky seafloor. We recommend developing a monitoring plan for seafloor litter by selecting representative sites for visual inspection that cover different depths and substrata in marine landscapes, and recording the litter collected or observed across all forms of seafloor sampling or imaging. We need better coverage and knowledge of status of seafloor litter for the whole Arctic and recommend initiatives to be taken for regions where such knowledge is lacking.
Classification and Soliton for a Generalized Fourth-Order Dispersive Nonlinear Schrödinger Equation in a Heisenberg Spin Chain
Authors: Yang Deniu
Published: November 2022

The main objective of this paper is to study bifurcations and solitons for a generalized fourth-order dispersive nonlinear Schrödinger equation in a Heisenberg spin chain via the theory of differential dynamical systems. By introducing the complex traveling wave transformation, we obtain the singular traveling wave system and the Hamiltonian function. By applying the classical analysis method, we investigate the bifurcations thoroughly and obtain the phase portraits of the bifurcations in four cases. Based on the phase portraits, we obtain a large number of analytic parametric representations for bounded solitons, including periodic wave solutions, solitary wave solutions, kink (anti-kink) wave solutions, compacton solutions, and a special class of bounded soliton solutions, corresponding to stable and unstable manifolds of the saddle point. These analytic parametric representations enhance the understanding of dynamic properties and characteristics of soliton solutions.
Characterization of Fractal Basins Using Deep Convolutional Neural Networks
Authors: Valle David , Wagemakers Alexandre , Daza Alvar , Sanjuán Miguel A. F.
Published: November 2022

Neural network models have recently demonstrated impressive prediction performance in complex systems where chaos and unpredictability appear. In spite of the research efforts carried out on predicting future trajectories or improving their accuracy compared to numerical methods, not sufficient work has been done on using deep learning techniques in which the unpredictability can be characterized of chaotic systems or give a general view of the global unpredictability of a system. In this work, we propose a novel approach based on deep learning techniques to measure the fractal dimension of the basins of attraction of the Duffing oscillator for a variety of parameters. As a consequence, we provide an algorithm capable of predicting fractal dimension measures as accurately as the box-counting algorithm, but with a computation speed about ten times faster.
Complex Dynamics of Predator–Prey Systems with Allee Effect
Authors: Zeng Yanni , Yu Pei
Published: November 2022

In this paper, we apply bifurcation theory to consider four predator–prey systems which include the Allee effect, and show that the species having a strong Allee effct may affect their predation and hence extinction risk. It is shown that the models with the Allee effect exhibit more complex dynamical behaviors compared with that without the Allee effect. In particular, two models with no Allee effect do not have Hopf bifurcation, but can have Hopf bifurcation with the Allee effect; and one model, which does not have Bogdanov–Takens bifurcation if no Allee effect is involved, can have Bogdanov–Takens bifurcation of codimension two. Especially, for one model with Holling type II functional response of the predator to the prey, the Allee effect not only completely changes the stability of the equilibrium at the origin, but also changes the supercritical Hopf bifurcation arising from an interior equilibrium to subcritical Hopf bifurcation with very limited parameter values to yield unstable limit cycles, and further increases the system’s stability.
Introduction
Authors: Frith Jordan , Read Sarah
Published: November 2022

This article is the introduction of the first of twoCommunication Design Quarterlyspecial issues focused on conceptualizations of infrastructure. This introduction explains the inspiration for these two special issues and details the growth of infrastructural research across the humanities and social sciences. This article also explains the structure of the issue and argues that the articles found across these two issues make a strong case for centering infrastructural knowledge in our work going forward.
Review of "Literacy as Conversation: Learning Networks in Urban and Rural Communities by Eli Goldblatt and David A. Jolliffe" Goldblatt, E., & Jolliffe, D. A. (2020). University Of Pittsburgh Press.
Authors: Lerma Corina
Published: November 2022

Eli Goldblatt and David A. Jolliffe's 2020
Literacy as Conversation: Learning Networks in Urban and Rural Communities
is to be interpreted as a "book of essays" and, more importantly, as vivid and lived conversations that aim to showcase nearly three decades of friendship between two colleagues concerned about meaningful community participation and literacy. This collection captures their reflections on their participation in community-based projects within the urban neighborhoods of Philadelphia and rural and semirural towns of Arkansas, but also offers an expanded and active understanding of literacy as social practice with complex relationships between sponsors, learning networks, power, and taking place in non-school environments having an access point through conversation and written symbols. Goldblatt and Jolliffe's endeavor to highlight the social connections and complexity of literacy aligns with their intent to include not just scholars in higher education, but also "everyday folk" or ordinary people including educators, government officials and policy makers, and people from all walks of life. As a scholar of color and teacher of a Hispanic-serving institution and as a community member of a predominantly Hispanic city in Texas, I was immediately intrigued and captured by the authors' commitment to highlight the stories of people who persevere and design interventions to construct hope and shape themselves and the world into a better place.
Fine-grained relational learning for few-shot knowledge graph completion
Authors: Yuan Xu , Lei Qihang , Yu Shuo , Xu Chengchuan , Chen Zhikui
Published: November 2022

Few-shot knowledge graph completion (FKGC) task aims to infer missing entities or relations by using few-shot support instances in the knowledge graph. Existing FKGC methods focus on the learning of few-shot relation representations, which are obtained by aggregating the neighbor information of each entity. However, most of these models take the entity's neighbor relations and entities as the same hierarchy and do not make fine-grained distinctions, resulting in entity embeddings with low expressiveness, which may further decrease the quality of learned few-shot relation embeddings. Moreover, many of those models directly use the concatenation of the entity embeddings as the relation representations, and neglect the valuable interaction between relations. In this paper, we propose a fine-grained relational learning framework IDEAL for few-shot knowledge graph completion task. Specifically, we first propose a unique hierarchical attention encoder to aggregate the neighbor information of each entity from two levels, i.e., the entity-relation level and the relation-entity level. Then a relation recoding validator is proposed to formulate the interaction between different relations. Instead of obtaining the few-shot relation representations by using the entity embeddings, the relation recoding validator module aggregates the neighbor relations of each entity to encode the few-shot relation, which can reduce the over-dependence on specific entities in the few-shot relation encoding phase. The relation recoding module is also extended with respect to the excellent performance of the transformer in modeling sequence information. We then introduce a transformer encoder to extract underlying and valuable sequence information between relations. Extensive experiments are conducted on two datasets, i.e., NELL and Wiki. The experimental results demonstrate that our model outperforms state-of-the-art FKGC methods. Besides, we devise the ablation study to demonstrate the effectiveness of each key component. The case study also shows the interpretability of our model intuitively.
Trust-aware location recommendation for user groups
Authors: Teoman Huseyin Alper , Karagoz Pinar
Published: November 2022

Recommender systems have become indispensable part of online environments. Product recommendations in ecommerce applications, location recommendations in location related applications, and user and post recommendations in online social networks are just a few examples in the world of online recommendations. The recommendations generated in such environments are mostly for individuals. However, increasing use of social networks and online communities lead to need for generating recommendations for a group of users for joint activities, such as eating out as a group or seeing a movie with friends. In the literature, there are studies proposing recommendation solutions for groups, but the number of such studies is very limited. In this work, we address the problem of location recommendation to a group of users, and the proposed solutions are based on Random Walk with Restart (RWR) algorithm on the social network graph. Another novel aspect of the proposed work is the use of trust factor of users in location-based social networks (LBSNs). In generating group recommendations, we follow two alternative paths. The first one aggregates the location recommendations that are generated with the Random Walk algorithm for each member in the group, taking the preferences and objectivity scores of the individuals into account. The second one is based on creating a group profile by blending preferences and venue category types, and using this group profile to run the Random Walk algorithm once. In both approaches trust factor of users is incorporated into the solutions within the social network graph. The experiments conducted on the data collected from the location based social network platform Foursquare have shown that the trust factor of users improves the performance of group recommendation system and the proposed algorithm provides recommendations to groups with high accuracy compared to the baselines.
Optimal Insurance Indemnity for the Insured with Low Risk Tolerance
Authors: Zhang Jiesong , Li Cailing
Published: November 2022

This study focuses on the optimal insurance for the insured with low risk tolerance from the perspective of rank‐dependent utility. Dissimilar to the widely employed assumption that the initial wealth of the insured can sufficiently cover any incurred premium and maximal possible loss, we assume that the policyholder may not possess sufficient initial wealth, thus exhibiting a low risk tolerance. Hence, we establish a corresponding insurance model in which the insured’s initial wealth is designed in such a manner that it only needs to cover the premium. Further, the model considers an introduced risk level that is less than the maximal possible loss. Owing to the lack of the condition of the sufficiency of initial wealth, the original optimization issue could not be converted into a canonical quantile‐optimization issue, as usual, and the quantile formulation could not be obtained directly. To overcome this challenge, we apply the calculus of variations method employing a variable upper limit that is related to the maximal risk level. Further, the explicit optimal solution bearing Yaari’s dual criterion is given, demonstrating that the optimal insurance policy with sufficient initial wealth represents a special case. Finally, numerical examples are presented to compare the indemnity with different risk levels.
Robustness Analysis of the Regional and Interregional Components of the Weighted World Air Transportation Network
Authors: Diop Issa Moussa , Diallo Cherif , Cherifi Chantal , Cherifi Hocine
Published: November 2022

The robustness of a system indicates its ability to withstand disturbances while maintaining its properties, performance, and efficiency. There are plenty of studies on the robustness of air transport networks in the literature. However, few works consider its mesoscopic organization. Building on the recently introduced component structure, we explore the impact of targeted attacks on the weighted world air transportation network on its components. Indeed, it contains five local components covering different regions (North America‐Caribbean, Europe‐Russia, East and Southeast Asia‐Oceania, Africa‐Middle East‐Southern Asia, and South America) and one global component linking these regions. We investigate targeted attacks based on influential weighted centrality measures (strength, betweenness, and PageRank). Results show that the local components gradually separate from the world air transportation network as the fraction of removed airports grows. The weighted betweenness attack removes fewer top airports to isolate the regions compared to its alternatives. Furthermore, it is still convenient to travel locally in the separate areas. In contrast, strength and PageRank attacks need to target more airports to split the network. However, they are more disruptive. Indeed, the size of the isolated local components reduces drastically, so it becomes more challenging to travel locally. Looking at the world air transportation network through its component structure reveals a new viewpoint on its resilence. It opens new perspectives to design more efficient attacks.
Effects of Bile Duct Ligation and Ghrelin Treatment on the Colonic Barrier and Microbiome of Mice
Authors: Ehlers Luise , Netz Leonard Andreas Wolfgang , Reiner Johannes , Berlin Peggy , Bannert Karen , Bastian Manuela , Zechner Dietmar , Lamprecht Georg , Jaster Robert
Published: November 2022

Introduction: Cholestatic liver disease (CLD) is associated with intestinal barrier dysfunction. The peptide hormone ghrelin may exert both hepatoprotective and barrier-strengthening effects. Here, we have evaluated these effects under the conditions of experimental cholestasis. Methods: C57BL/6J mice with bile duct ligation (BDL) or sham surgery were treated with ghrelin or solvent for 9 days. Liver injury was assessed by histological and laboratory analyses. Paracellular macromolecule permeability and transmural electrical resistance (TMER) of colonic tissues were measured using a Ussing chamber. Expression of tight junction (TJ) genes was quantified by real-time PCR. Amplicon metagenomic sequencing was employed to analyze bacterial 16S rRNA from colonic stool samples. Results: Mice with BDL exhibited weight loss and signs of severe liver injury. These changes were unaffected by ghrelin treatment. FITC-4-kDa-dextran flux was increased and TMER decreased after BDL. Treatment with ghrelin tended to reduce these effects. Furthermore, application of ghrelin was associated with higher mRNA levels of claudin-4, occludin, and ZO-1 in colonic tissues of mice with BDL. Reduced alpha-diversity of the microbiome was observed in solvent-treated mice with BDL but not in ghrelin-treated animals. Conclusion: Ghrelin treatment did not improve weight loss and liver damage but increased gene expression of colonic TJ proteins and restored the alpha-diversity of the microbiome. Since protective effects of ghrelin might be masked by the severity of the model, we suggest follow-up studies in models of milder CLD.
Relapses of Immune Thrombocytopenia after the Second and Booster Doses of BNT162b2 Vaccine
Authors: Ratajczak-Enselme Maja , Mutoni Guy-Clébert , Desmeules Jules , Favet Laurence , Ing Lorenzini Kuntheavy
Published: November 2022

We present here a 65-year-old male patient known for immune thrombocytopenic purpura (ITP) and fluctuating platelet count who experienced a severe exacerbation of thrombocytopenia following BNT162b2 COVID-19 vaccination. One month after the second dose, he presented petechiae and asthenia with isolated thrombocytopenia (platelet count: 3 × 109/L). He recovered after a 4-day course of intravenous corticosteroid treatment and intravenous immunoglobulin therapy. Eight months later, his platelet count was within the normal range, and he received a booster dose of vaccine after premedication with prednisone. Eight days later, his platelet count dropped to 29 × 109/L, but he remained asymptomatic. He received a rescue treatment with prednisone followed by rituximab over 4 weeks, allowing progressive improvement. Our case suggests a strong association between COVID-19 vaccination and the exacerbation of ITP.
Prediction of Cardiac Toxicity by Measurement of Coronary Artery Calcium Scoring Method Using Chest Computed Tomography in Early Breast Cancer Patients Treated with Trastuzumab
Authors: Yoon Chang Ik , Chang Suyon , Park Jeaneum , Kim Dooreh , Lee Young Joo , Bae Soo Youn , Park Woo-Chan
Published: November 2022

Background: In human epidermal growth factor receptor 2 (HER2)-positive early stage breast cancer, prediction of trastuzumab-related cardiac toxicity remains a challenge. The coronary calcium artery (CAC) reflects the total coronary plaque burden, which predicts the risk of atherosclerosis. We investigated the prediction of left ventricular ejection fraction (LVEF) decline in breast cancer according to CAC scores. Methods: A total of 347 patients were enrolled from Seoul St Mary’s Hospital between January 2010 and December 2019. Chest computed tomography (CT) was performed at a single tertiary center. Patients who received trastuzumab for HER2-positive early breast cancer were included in this study. Results: Of the 347 patients, 312 and 35 had CAC scores of 0 and ≥1, respectively. The CAC ≥1 group was associated with older age, body mass index, and receipt of left breast irradiation. The CAC ≥1 group was significantly associated with LVEF decline (absolute value, ≤50%) (hazard ratio [HR] 12.038, 95% confidence interval [CI] 2.845–50.937, p = 0.001), LVEF decline (absolute value, ≤55%) (HR 4.439, 95% CI: 1.787–11.028, p = 0.001), and decline in LVEF of ≥10% points compared with baseline echography (HR 5.083, 95% CI: 1.658–15.582, p = 0.004). Even after adjusting for other clinical factors, CAC ≥1 remained a significant predictor of decreased LVEF. Conclusion: Our findings suggest that the CAC score is a significant predictor of cardiac toxicity following trastuzumab treatment in HER2-positive breast cancer. Therefore, CAC measurement could reduce cardiac toxicity by distinguishing patients at high risk for trastuzumab.
Efficacy and Safety of Alirocumab in Children and Adolescents With Homozygous Familial Hypercholesterolemia: Phase 3, Multinational Open-Label Study
Authors: Bruckert Eric , Caprio Sonia , Wiegman Albert , Charng Min-Ji , Zárate-Morales Cézar A. , Baccara-Dinet Marie T. , Manvelian Garen , Ourliac Anne , Scemama Michel , Daniels Stephen R.
Published: November 2022

Background:

Despite progress in treating homozygous familial hypercholesterolemia, most patients do not achieve low-density lipoprotein cholesterol (LDL-C) targets. This study examined efficacy and safety of the PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor, alirocumab, in pediatric patients (aged 8–17 years) with inadequately controlled homozygous familial hypercholesterolemia.

Methods:

In this open-label, single-arm, multinational, Phase 3 study, patients (n=18) received alirocumab 75 mg or 150 mg (bodyweight <50 kg/≥50 kg) every 2 weeks as an adjunct to background treatment. The primary endpoint was percent change in LDL-C from baseline to Week 12. Secondary endpoints included changes in LDL-C and other lipid parameters up to 48 weeks, safety/tolerability, and alirocumab pharmacokinetics.

Results:

The mean age of patients was 12.4 years; 16/18 (89%) had mutations in the low-density lipoprotein receptor gene
(LDLR
) and 2/18 (11%) had mutations in the LDLR adapter protein 1 gene (
LDLRAP1).
At baseline, mean LDL-C (standard deviation) was 373.0 (193.5) mg/dL, which decreased by 4.1% at Week 12 (primary endpoint) and 11.4%, 13.2%, and 0.4% at Weeks 4, 24, and 48, respectively. At Week 12, 9/18 (50%) patients achieved LDL-C reductions ≥15%. Mean absolute LDL-C decreases ranged from 25 to 52 mg/dL over follow-up. A post hoc analysis demonstrated heterogeneity of responses according to genotype. There were no unexpected safety/tolerability findings. Free PCSK9 was reduced to near zero for all patients at Weeks 12 and 24.

Conclusions:

The study supports the efficacy and safety of alirocumab as a potential adjunct to treatment for some pediatric patients with homozygous familial hypercholesterolemia.

Registration:

URL:
https://www.clinicaltrials.gov
; NCT03510715.
Senecio namibensis (Asteraceae: Senecioneae), a new species from Namibia
Authors: SWANEPOEL WESSEL , BECKER ROLF , DE CAUWER VERA , VAN WYK ABRAHAM E.
Published: November 2022

Senecio namibensis is described as a new species known only from the northern part of the Namib Desert in northwestern Namibia. It is a range-restricted species near-endemic to the Kaokoveld Centre of Endemism. These dwarf shrubs grow on rocky outcrops under harsh desert conditions. Diagnostic characters for Senecio namibensis include the annual or perennial habit, succulent leaves, and radiate capitula with 3–6 yellow ray florets. A comparison of some of the more prominent morphological features to differentiate between S. namibensis and its possible nearest relatives, S. englerianus and S. flavus, is provided. All three species have superficially similar looking succulent leaves, but an obvious difference is that the capitula in S. englerianus are discoid and in S. flavus disciform or obscurely radiate. Based on IUCN Red List categories and criteria, a conservation assessment of Least Concern (LC) is recommended for the new species.
Neokamalomyces indicus gen. nov., sp. nov. (Mycosphaerellaceae)—a Septoria-like genus from India
Authors: YADAV SANJAY , VERMA SANJEET KUMAR , SINGH RAGHVENDRA , SINGH VINAY KUMAR , CHAURASIA BALMUKUND , SINGH PARAS NATH , KUMAR SHAMBHU
Published: November 2022

A new hyaline coelomycetous fungus discovered on living leaves of Ficus benghalensis (Moraceae) is described and illustrated. Morphologically, it is similar to Septoria or septoria-like genus, but based on cultural characteristics and multigene (LSU-RPB2-ITS) phylogenetic analysis this strain represents an additional lineage in Mycosphaerellaceae. Hence, a new genus and species, Neokamalomyces indicus is proposed.
Reinstatement of the independent specific status of Chrysanthemum neo-oreastrum (Asteraceae, Anthemideae)
Authors: CHI XIAO-RUI , WANG LONG
Published: November 2022

Chrysanthemum neo-oreastrum (Asteraceae, Anthemideae) has been placed in synonymy with C. hypargyreum. Based on our examination of herbarium specimens and field investigation, C. neo-oreastrum was found to be easily distinguishable from C. hypargyreum morphologically. Its independent specific status is therefore resurrected. An emended description and a distribution map are also provided for this species.
Physical Activity in South Asian Indians: A Systematic Review of Randomized Controlled Trials
Authors: Daniel Manju , Buchholz Susan , Fogg Louis
Published: November 2022

This review systematically examines the characteristics and effectiveness of randomized controlled trials with aerobic physical activity (PA) interventions tailored to South Asian Indians (SAIs). PubMed/MEDLINE, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CINAHL, and Google Scholar were searched. The search yielded 1,842 studies; 11 met the criteria. The Center for Evidence-Based Medicine’s critical appraisal tool was used to assess the quality of studies. Studies that used supervised structured PA sessions, educational material in SAI languages, motivational strategies, and positive reinforcement for goal setting, reported significant improvement in PA ( p < .05; Cohen’s d ≤ 0.3 to >0.8). Future PA studies in India featuring SAIs would benefit from clinic-based one-on-one structured aerobic PA interventions. In contrast, SAI immigrants in Western countries would benefit from community-based structured aerobic PA interventions that are offered in groups and culturally adapted.
Surveillance of ADHD Among Children in the United States: Validity and Reliability of Parent Report of Provider Diagnosis
Authors: Cree Robyn A. , Bitsko Rebecca H. , Danielson Melissa L. , Wanga Valentine , Holbrook Joseph , Flory Kate , Kubicek Lorraine F. , Evans Steven W. , Owens Julie Sarno , Cuffe Steven P.
Published: November 2022

Objective:

To evaluate the appropriateness of parent-reported diagnosis of ADHD as a surveillance tool.

Method:

We assessed agreement over time and concordance of parent-reported diagnosis against Diagnostic and Statistical Manual (DSM)-based criteria. We compared concordance of diagnosis and DSM-based criteria by child characteristics, including treatment.

Results:

Among parents who reported their child had ADHD, 95.7% reported it again 2 years later. Comparing diagnosis with DSM-based criteria, specificity and negative predictive value were high, sensitivity was moderate, and positive predictive value was low. Most children with an ADHD diagnosis who did not meet DSM-based criteria met sub-threshold criteria or took medication for ADHD. Concordance differed by child characteristics and treatment.

Conclusion:

Parent-reported diagnosed ADHD is reliable over time. Although differences in parent-reported diagnosis and DSM-based criteria were noted, these may reflect children with milder symptoms or treated ADHD. Parent-report of child ADHD ever diagnosis may be a good single-item indicator for prevalence.