bluuebunny/crossref_metadata_2025 huggingface dataset:
A snapshot of the Physcomitrella N-terminome reveals N-terminal methylation of organellar proteins
Authors: Hoernstein Sebastian N.W. , Schlosser Andreas , Fiedler Kathrin , van Gessel Nico , Igloi Gabor L. , Lang Daniel , Reski Ralf
Published: June 2024

Post- or co-translational N-terminal modifications of proteins influence their half-life as well as mediating protein sorting to organelles via cleavable N-terminal sequences that are recognized by the respective translocation machinery. Here, we provide an overview on the current modification state of the N-termini of over 4500 proteins from the model moss Physcomitrella (Physcomitrium patens) using a compilation of 24 N-terminomics datasets. Our data reveal distinct proteoforms and modification states and confirm predicted targeting peptide cleavage sites of 1144 proteins localized to plastids and the thylakoid lumen, to mitochondria, and to the secretory pathway. Additionally, we uncover extended N-terminal methylation of mitochondrial proteins. Moreover, we identified PpNTM1 (P. patens alpha N-terminal protein methyltransferase 1) as a candidate for protein methylation in plastids, mitochondria and the cytosol. These data can now be used to optimize computational targeting predictors, for customized protein fusions and their targeted localization in biotechnology, and offer novel insights into potential dual targeting of proteins.

Key message

Analysis of the N-terminome of Physcomitrella reveals N-terminal monomethylation of nuclear encoded, mitochondria-localized proteins.

Graphical abstract
Reevaluating the Neural Noise Hypothesis in Dyslexia: Insights from EEG and 7T MRS Biomarkers
Authors: Glica Agnieszka , Wasilewska Katarzyna , Jurkowska Julia , Żygierewicz Jarosław , Kossowski Bartosz , Jednoróg Katarzyna
Published: June 2024

The neural noise hypothesis of dyslexia posits an imbalance between excitatory and inhibitory (E/I) brain activity as an underlying mechanism of reading difficulties. This study provides the first direct test of this hypothesis using both EEG power spectrum measures in 120 Polish adolescents and young adults (60 with dyslexia, 60 controls) and glutamate (Glu) and gamma-aminobutyric acid (GABA) concentrations from magnetic resonance spectroscopy (MRS) at 7T MRI scanner in half of the sample. Our results, supported by Bayesian statistics, show no evidence of E/I balance differences between groups, challenging the hypothesis that cortical hyperexcitability underlies dyslexia. These findings suggest alternative mechanisms must be explored and highlight the need for further research into the E/I balance and its role in neurodevelopmental disorders.
Transcriptional reprogramming deploys a compartmentalized “timebomb” inCatharanthus roseusto fend off chewing herbivores
Authors: Liu Yongliang , Shi Jizhe , Patra Barunava , Singh Sanjay Kumar , Liu Xiaoyu , Li Yongqing , Wang Ying , Zhou Xuguo , Pattanaik Sitakanta , Yuan Ling
Published: June 2024

The evolutionary arms-race between plants and insects has led to key adaptive innovations that drive diversification. Alkaloids are well-documented anti-herbivory compounds in plant chemical defenses, but how these specialized metabolites are allocated to cope with both biotic and abiotic stresses concomitantly is largely unknown. To examine how plants prioritize their metabolic resources responding to herbivory and cold, we integrated dietary toxicity bioassay in insects with co-expression analysis, hierarchical clustering, promoter assay, and protein-protein interaction in plants.Catharanthus roseus,a medicinal plant known for its insecticidal property against chewing herbivores, produces two terpenoid indole alkaloid monomers, vindoline and catharanthine. Individually, they exhibited negligible toxicity againstManduca sexta,a chewing herbivore; their condensed product, anhydrovinblastine, however, was highly toxic. Such unique insecticidal mode of action demonstrates that terpenoid indole alkaloid “timebomb” can only be activated when the two spatially isolated monomeric precursors are dimerized by herbivory. Without initial selection pressure and apparent fitness costs, this adaptive chemical defense against herbivory is innovative and sustainable.

The biosynthesis of insecticidal terpenoid indole alkaloids is induced by herbivory but suppressed by cold. Here, we identified a transcription factor,Herbivore InducedVindoline-geneExpression (HIVE), that coordinates the production of terpenoid indole alkaloids in response to herbivory and cold stress. The HIVE-mediated transcriptional reprogramming allows this herbaceous perennial to allocate their metabolic resources for chemical defense at a normal temperature, when herbivory pressure is high, but switches to cold tolerance under a cooler temperature, when insect infestation is secondary.
Direct computations of viscoelastic moduli of biomolecular condensates
Authors: Cohen Samuel R. , Banerjee Priya R. , Pappu Rohit V.
Published: June 2024

In vitrofacsimiles of biomolecular condensates are formed by different types of intrinsically disordered proteins including prion-like low complexity domains (PLCDs). PLCD condensates are viscoelastic materials defined by time-dependent, sequence-specific complex shear moduli. Here, we show that viscoelastic moduli can be computed directly using a generalization of the Rouse model and information regarding intra- and inter-chain contacts that is extracted from equilibrium configurations of lattice-based Metropolis Monte Carlo (MMC) simulations. The key ingredient of the generalized Rouse model is the Zimm matrix that we compute from equilibrium MMC simulations. We compute two flavors of Zimm matrices, one referred to as the single-chain model that accounts only for intra-chain contacts, and the other referred to as a collective model, that accounts for inter-chain interactions. The single-chain model systematically overestimates the storage and loss moduli, whereas the collective model reproduces the measured moduli with greater fidelity. However, in the long time, low-frequency domain, a mixture of the two models proves to be most accurate. In line with the theory of Rouse, we find that a continuous distribution of relaxation times exists in condensates. The single crossover frequency between dominantly elastic versus dominantly viscous behaviors is influenced by the totality of the relaxation modes. Hence, our analysis suggests that viscoelastic fluid-like condensates are best described as generalized Maxwell fluids. Finally, we show that the complex shear moduli can be used to solve an inverse problem to obtain distributions of relaxation times that underlie the dynamics within condensates.
Optimized phenotype definitions boost GWAS power
Authors: Zietz Michael , Brown Kathleen LaRow , Gisladottir Undina , Tatonetti Nicholas P.
Published: June 2024

Abstract

Complex diseases are among the central challenges facing the world, and genetics underlie a large fraction of the risk. Observational data, such as electronic health records (EHR), offer numerous advantages in the study of complex disease genetics. These include their large scale, cost-effectiveness, information on many different conditions, and future scalability with the widespread adoption of EHRs. Observational data, however, are challenging for research as they reflect various factors including the healthcare process and access to care, as well as broader societal effects like systemic biases. Here, we introduce MaxGCP, a novel phenotyping method designed to purify the genetic signal in observational data. Our approach optimizes a phenotype definition to maximize its coheritability with the complex trait of interest. We validated the method in simulations and applied it to real data analyses of stroke and Alzheimer’s disease. We found that MaxGCP improves genomewide association study (GWAS) power compared to conventional, single-code phenotype definitions. MaxGCP is a powerful tool for genetic discovery in observational data, and we anticipate that it will be broadly useful for studying complex diseases using observational data.
Genetic variation in recalcitrant repetitive regions of the Drosophila melanogaster genome
Authors: Shukla Harsh , Chakraborty Mahul , Emerson J.J.
Published: June 2024

Many essential functions of organisms are encoded in highly repetitive genomic regions, including histones involved in DNA packaging, centromeres that are core components of chromosome segregation, ribosomal RNA comprising the protein translation machinery, telomeres that ensure chromosome integrity, piRNA clusters encoding host defenses against selfish elements, and virtually the entire Y chromosome. These regions, formed by highly similar tandem arrays, pose significant challenges for experimental and informatic study, impeding sequence-level descriptions essential for understanding genetic variation. Here, we report the assembly and variation analysis of such repetitive regions in Drosophila melanogaster, offering significant improvements to the existing community reference assembly. Our work successfully recovers previously elusive segments, including complete reconstructions of the histone locus and the pericentric heterochromatin of the X chromosome, spanning the Stellate locus to the distal flank of the rDNA cluster. To infer structural changes in these regions where alignments are often not practicable, we introduce landmark anchors based on unique variants that are putatively orthologous. These regions display considerable structural variation between different D. melanogaster strains, exhibiting differences in copy number and organization of homologous repeat units between haplotypes. In the histone cluster, although we observe minimal genetic exchange indicative of crossing over, the variation patterns suggest mechanisms such as unequal sister chromatid exchange. We also examine the prevalence and scale of concerted evolution in the histone and Stellate clusters and discuss the mechanisms underlying these observed patterns.
A 5-day course of rTMS before pain onset ameliorates future pain and increases sensorimotor peak alpha frequency
Authors: Chowdhury Nahian S , Taseen Khandoker , Chiang Alan , Chang Wei-Ju , Millard Samantha K , Seminowicz David A , Schabrun Siobhan M
Published: June 2024

Repetitive transcranial magnetic stimulation (rTMS) has shown promise as an intervention for pain. An unexplored research question is whether the delivery of rTMSprior to pain onsetmight protect against a future episode of prolonged pain. The present study aimed to determine i) whether 5 consecutive days of rTMS delivered prior to experimentally-induced prolonged jaw pain could reduce future pain intensity and ii) whether any effects of rTMS on pain were mediated by changes in corticomotor excitability (CME) and/or sensorimotor peak alpha frequency (PAF). On each day from Day 0-4, forty healthy individuals received a single session of active (n = 21) or sham (n = 19) rTMS over the left primary motor cortex. PAF and CME were assessed on Day 0 (before rTMS) and Day 4 (after rTMS). Prolonged pain was induced via intramuscular injection of nerve growth factor (NGF) in the right masseter muscle after the final rTMS session. From Days 5-25, participants completed twice-daily electronic dairies including pain on chewing and yawning (primary outcomes), as well as pain during other activities (e.g. talking), functional limitation in jaw function and muscle soreness (secondary outcomes). Compared to sham, individuals who received active rTMS subsequently experienced lower pain on chewing and yawning. Although active rTMS increased PAF, the effects of rTMS on pain were not mediated by changes in PAF or CME. This study is the first to show that rTMS deliveredpriorto pain onset can protect against future pain and associated functional impairment. Thus, rTMS may hold promise as a prophylactic intervention for persistent pain.
Receptor- ligand interactions in plant inmate immunity revealed by AlphaFold protein structure prediction
Authors: Wang Li , Jia Yulin , Osakina Aron , Olsen Kenneth M. , Huang Yixiao , Jia Melissa H. , Ponniah Sathish , Pedrozo Rodrigo , Nicolli Camila , Edwards Jeremy D.
Published: June 2024

One of the common mechanisms to trigger plant innate immunity is recognition of pathogen avirulence gene products directly by products of major resistance (R) genes in a gene for gene manner. In the USA, theRgenes,Pik-s, PiKh/m, andPi-ta, Pi-39(t), andPtrgenes have been effectively deployed to prevent the infections ofM. oryzaeraces, IB49, and IC17 for some time.Pi-9is only recently being deployed to provide overlapped and complimentary resistance toMagnaporthe oryzaeraces IB49, IC17 and IE1k in the USA. Pi-ta, Pi-39(t), Pi9 are major nuclear binding site-leucine rich (NLR) proteins, and Ptr is an atypical R protein with 4 armadillo repeats. AlphaFold is an artificial intelligence system that predicts a protein 3D structure from its amino acid sequence. Here we report genome sequence analyses of the effectors and avirulence (AVR) genes,AVR-PitaandAVR-Pik, andAVR-Pi9, in 3 differentialM. oryzaeraces. Using AlphaFold 2 and 3 we find strong evidence of direct interactions of products of resistance genesPi-taandPikwithM. oryzaeavirulence (AVR) genes,AVR-PitaandAVR-Pikrespectively. We also found that AVR-Pita interacts with Pi-39(t) and Ptr, and Pi9 interacts with both AVR-Pi9 and AVR-Pik. Validation of direct interactions of two pairs of R and AVR proteins supported a direct interaction mechanism of plant innate immunity. Detecting interaction of both Ptr and Pi39(t) with AVR-Pita, and Pi-9 with both AVR-Pi9 and AVR-Pik, revealed a new insight into recognition of pathogen signaling molecules by these host R genes in triggering plant innate immunity.
Host population structure and rare dispersal events drive leptospirosis transmission patterns amongRattus norvegicusin Boston, Massachusetts, US
Authors: Stone Nathan E. , Hamond Camila , Clegg Joel , McDonough Ryelan F. , Bourgeois Reanna M. , Ballard Rebecca , Thornton Natalie B. , Nuttall Marianece , Hertzel Hannah , Anderson Tammy , Whealy Ryann N. , Timm Skylar , Roberts Alexander K. , Barragán Verónica , Phipatanakul Wanda , Leibler Jessica H. , Benson Hayley , Specht Aubrey , White Ruairi , LeCount Karen , Furstenau Tara N. , Galloway Renee L. , Hill Nichola J. , Madison Joseph D. , Fofanov Viacheslav Y. , Pearson Talima , Sahl Jason W. , Busch Joseph D. , Weiner Zachary , Nally Jarlath E. , Wagner David M. , Rosenbaum Marieke H.
Published: June 2024

Leptospirosis (caused by pathogenic bacteria in the genusLeptospira) is prevalent worldwide but more common in tropical and subtropical regions. Transmission can occur following direct exposure to infected urine from reservoir hosts, such as rats, or a urine-contaminated environment, which then can serve as an infection source for additional rats and other mammals, including humans. The brown rat,Rattus norvegicus, is an important reservoir of leptospirosis in urban settings. We investigated leptospirosis among brown rats in Boston, Massachusetts and hypothesized that rat dispersal in this urban setting influences the movement, persistence, and diversity ofLeptospira. We analyzed DNA from 328 rat kidney samples collected from 17 sites in Boston over a seven-year period (2016–2022); 59 rats representing 12 of 17 sites were positive forLeptospira. We used 21 neutral microsatellite loci to genotype 311 rats and utilized the resulting data to investigate genetic connectivity among sampling sites. We generated whole genome sequences for 28Leptospiraisolates obtained from frozen and fresh tissue from some of the 59Leptospira-positive rat kidneys. When isolates were not obtained, we attemptedLeptospiragenomic DNA capture and enrichment, which yielded 14 additionalLeptospiragenomes from rats. We also generated an enrichedLeptospiragenome from a 2018 human case in Boston. We found evidence of high genetic structure and limited dispersal among rat populations that is likely influenced by major roads and/or other unknown dispersal barriers, resulting in distinct rat population groups within the city; at certain sites these groups persisted for multiple years. We identified multiple distinct phylogenetic clades ofL. interrogansamong rats, with specific clades tightly linked to distinct rat populations. This pattern suggestsL. interroganspersists in local rat populations and movement of leptospirosis in this urban rat community is driven by rat dispersal. Finally, our genomic analyses of the 2018 human leptospirosis case in Boston suggests a link to rats as the source. These findings will be useful for guiding rat control and human leptospirosis mitigation efforts in this and other urban settings.
A commensal-derived sugar protects against metabolic disease
Authors: Tan Chin Yee , Jiang Danting , Theriot Barbara S. , Rao Meghana V. , Surana Neeraj K.
Published: June 2024

Obesity is a worsening global epidemic that is regulated by the microbiota through unknown bacterial factors. We discovered a human-derived commensal bacterium,Clostridium immunis, that protects against metabolic disease by secreting a phosphocholine-modified exopolysaccharide. Genetic interruption of the phosphocholine biosynthesis locus (licABC) results in a functionally inactive exopolysaccharide, which demonstrates the critical requirement for this phosphocholine moiety. ThisC. immunisexopolysaccharide acts via group 3 innate lymphoid cells and modulating IL-22 levels, which results in a reduction in serum triglycerides, body weight, and visceral adiposity. Importantly, phosphocholine biosynthesis genes are less abundant in humans with obesity or hypertriglyceridemia, findings that suggest the role of bacterial phosphocholine is conserved across mice and humans. These results define a bacterial molecule—and its key structural motif—that regulates host metabolism. More broadly, they highlight how small molecules, such as phosphocholine, may help fine-tune microbiome– immune–metabolism interactions.
Neurologic outcomes in people with multiple sclerosis treated with immune checkpoint inhibitors for oncologic indications
Authors: Quinn Carson M. , Rajarajan Prashanth , Gill Alexander , Kopinsky Hannah , Wolf Andrew B. , De Camargo Celeste Soares , Lamb Jessica , Bacon Tamar , Murray Joseph , Probasco John C. , Galetta Kristin , Kantor Daniel , Coyle Patricia K. , Bhise Vikram , Alvarez Enrique , Conway Sarah , Bhattacharyya Shamik , Kister Ilya
Published: June 2024

Objective

To assess the prevalence of multiple sclerosis (MS) activity, as well as neurologic and non-neurologic immune-related adverse events (irAEs) in persons with MS (pwMS) treated with immune checkpoint inhibitors (ICIs) for cancer.

Background

ICIs are associated with irAEs and exacerbation of certain preexisting autoimmune diseases. PwMS are generally excluded from ICI clinical trials, so data on the safety of these drugs in pwMS is limited.

Design/Methods

Participating sites were recruited through the Medical Partnership 4 MS+ (MP4MS+) listserv. Seven large academic centers participated in the study, each conducting a systematic search of their electronic medical record system for patients with MS and ICI exposure. Demographics and data on MS and cancer history, treatments, and outcomes were abstracted from patient charts using a structured instrument.

Results

We identified 66 pwMS (median age 66 years, 73% female, 68% not on disease-modifying therapy (DMT) for MS) who were treated with ICIs for lung cancers (35%), melanoma (21%) or other oncologic indications. During post-ICI follow-up (median: 11.7 months, range 0.2-106.3 months), two pwMS (3%) had relapse or MRI activity, three (5%) had neurologic irAEs, and 21 (32%) had non-neurologic irAEs. At the last follow-up, 25 (38%) subjects had partial or complete remission of their cancer while 35 (53%) were deceased.

Conclusions

In this multi-institutional systematic retrospective study of predominantly older pwMS who were off DMTs, MS activity and neurologic irAEs following ICI treatment were rare, suggesting that preexisting MS should not preclude the use of ICIs.
Artificial Intelligence in Depression – Medication Enhancement (AID-ME): A Cluster Randomized Trial of a Deep Learning Enabled Clinical Decision Support System for Personalized Depression Treatment Selection and Management
Authors: Benrimoh David , Whitmore Kate , Richard Maud , Golden Grace , Perlman Kelly , Jalali Sara , Friesen Timothy , Barkat Youcef , Mehltretter Joseph , Fratila Robert , Armstrong Caitrin , Israel Sonia , Popescu Christina , Karp Jordan F. , Parikh Sagar V. , Golchi Shirin , Moodie Erica EM , Shen Junwei , Gifuni Anthony J. , Ferrari Manuela , Sapra Mamta , Kloiber Stefan , Pinard Georges-F. , Dunlop Boadie W. , Looper Karl , Ranganathan Mohini , Enault Martin , Beaulieu Serge , Rej Soham , Hersson-Edery Fanny , Steiner Warren , Anacleto Alexandra , Qassim Sabrina , McGuire-Snieckus Rebecca , Margolese Howard C.
Published: June 2024

Background

There has been increasing interest in the use of Artificial Intelligence (AI)-enabled clinical decision support systems (CDSS) for the personalization of major depressive disorder (MDD) treatment selection and management, but clinical studies are lacking. We tested whether a CDSS that combines an AI which predicts remission probabilities for individual antidepressants and a clinical algorithm based on treatment can improve MDD outcomes.

Methods

This was a multicenter, cluster randomized, patient-and-rater blinded and clinician-partially-blinded, active-controlled trial that recruited outpatient adults with moderate or greater severity MDD. All patients had access to a patient portal to complete questionnaires. Clinicians in the active group had access to the CDSS; clinicians in the active-control group received patient questionnaires; both groups received guideline training. Primary outcome was remission (<11 points on the Montgomery Asberg Depression Rating Scale (MADRS)) at study exit.

Results

47 clinicians were recruited at 9 sites. Of 74 eligible patients, 61 patients completed a post-baseline MADRS and were analyzed. There were no differences in baseline MADRS (p = 0.153). There were more remitters in the active (n= 12, 28.6%) than in the active-control (0%) group (p = 0.012, Fisher’s exact). Of three serious adverse events, none were caused by the CDSS. Speed of improvement was higher in the Active than the Control group (1.26 vs. 0.37, p = 0.03).

Conclusions

While limited by sample size and the lack of primary care clinicians, these results demonstrate preliminary evidence that longitudinal use of an AI-CDSS can improve outcomes in moderate and greater severity MDD.
High-field/high-frequency electron spin resonances of Fe-doped
β−Ga2O3
by terahertz generalized ellipsometry: Monoclinic symmetry effects
Authors: Richter Steffen , Knight Sean , Bulancea-Lindvall Oscar , Mu Sai , Kühne Philipp , Stokey Megan , Ruder Alexander , Rindert Viktor , Ivády Viktor , Abrikosov Igor A. , Van de Walle Chris G. , Schubert Mathias , Darakchieva Vanya
Published: June 2024

We demonstrate detection and measurement of electron paramagnetic spin resonances (EPR) of iron defects in β−Ga2O3 utilizing generalized ellipsometry at frequencies between 110 and 170 GHz. The experiments are performed on an Fe-doped single crystal in a free-beam configuration in reflection at 45∘ and magnetic fields between 3 and 7 T. In contrast with low-field, low-frequency EPR measurements, we observe all five transitions of the s=5/2 high-spin state Fe3+ simultaneously. We confirm that ferric Fe3+ is predominantly found at octahedrally coordinated Ga sites. We obtain the full set of fourth-order monoclinic zero-field splitting parameters for both octahedrally and tetrahedrally coordinated sites by employing measurements at multiple sample azimuth rotations. The capability of high-field EPR allows us to demonstrate that simplified second-order orthorhombic spin Hamiltonians are insufficient, and fourth-order terms as well as consideration of the monoclinic symmetry are needed. These findings are supported by computational approaches based on density-functional theory for second-order and on ligand-field theory for fourth-order parameters of the spin Hamiltonian. Terahertz ellipsometry is a way to measure spin resonances in a cavity-free setup. Its possibility of varying the probe frequency arbitrarily without otherwise changing the experimental setup offers unique means of truly disentangling different components of highly anisotropic spin Hamiltonians.

Published by the American Physical Society
2024
My views matter: what do service users and their families want from residential and in-patient learning disabilities services in Norfolk?
Authors: Spall John
Published: June 2024

Purpose

An important finding of the Safeguarding Adults Review into events at Cawston Park was that the views of patients and their families were systematically ignored by the hospital. The purpose of this paper is to report on a review of people’s experiences of residential and secure in-patient services in Norfolk for those with learning disabilities and autistic people. It discusses overall reported levels of satisfaction, how well people and their families felt they were listened to by services and what people valued most in services.

Design/methodology/approach

The main research tools were visits to services to talk to people and observe them receiving care, along with listening sessions outside homes and interviews with relatives.

Findings

Most people spoken to were happy with how they were listened to, but there is room for improvement. People particularly valued connections with staff based on reciprocity, long-term relationships and, for some, family-like relationships, and were unhappy when these were inconsistent or absent. People also enjoyed the opportunity to develop relationships with people outside their service, and especially with non-disabled people, something that was rare for most people. Relatives appreciated transparency of communication and openness to negotiation in home managers, especially when problems or disagreements arose.

Originality/value

The findings suggest that the severe problems with listening at Cawston Park are not more widespread across the sector in Norfolk. However, progress is needed to improve the consistency of listening across services and to develop services informed by what people value most in services around quality relationships, communication and social inclusion.
Bibliometric analysis of income inequality in Africa
Authors: Raimi Rasaq , Phiri Andrew
Published: June 2024

Purpose

The purpose of the study is to provide a bibliometric review of scientific articles published on “Income inequality in Africa” in order to understand the patterns of research on the topic and identify agendas for future research.

Design/methodology/approach

We conduct a bibliometric analysis on 459 research publications between 1993 and 2023 using the biblioshiny function of bibliometrix package of R-studio to map out and analyze the bibliometric data.

Findings

The findings from our analysis can be summarized in five points. Firstly, African researchers are underrepresented on a global scale and yet are dominant at institutional and author levels. Secondly, most dominant research has not being published in top 100 tanked economic journals. Thirdly, there is underrepresentation of females and white males in research output. Fourthly, there are weak author collaborations on the topic and currently the authors with higher collaborative partnerships tend to have more research output and higher citations. Lastly, we find that authors who include simple terms such as “Income inequality”, “Africa”, “poverty” and “economic growth” as keywords in their studies tend to have higher visibility.

Originality/value

This is first study to perform a bibliometric analysis for research on “Income inequality in Africa”.
The impact of the Tax Cuts and Jobs Act on the true interest cost of bank-qualified tax-exempt bond issues
Authors: Benson Earl D. , Marks Barry R.
Published: June 2024

Purpose

The Tax Cuts and Jobs Act of 2017 (TCJA) substantially lowered the corporate tax rate, making tax-exempt municipal bond issues less attractive investments for banks, savings and loan associations and insurance companies. To provide a benefit for small issuers the current Internal Revenue Code has a special provision that allows banks and S&Ls to deduct 80% of the borrowing costs for “bank-qualified” bonds – tax-exempt bonds from issuers who issue no more than $10 million in bonds during a year. This study examines whether the relationship between the true interest cost (TIC) on bank-qualified bonds and other tax-exempt bonds changed with the passage of the TCJA.

Design/methodology/approach

Using linear regression analysis this paper compares the TIC of bank-qualified bonds with the TIC of bonds not bank-qualified using a sample of bonds both before and after the passage of TCJA.

Findings

Prior to the passage of the TCJA, this study observes that these “bank-qualified” bond issues had a lower true interest cost than other tax-exempt bond issues; however, after passage of the TCJA, the difference in the true interest cost between “bank-qualified” bond issues and other tax-exempt bond issues dramatically decreased.

Practical implications

It appears that the benefit for small bond issuers is greatly reduced after corporate tax rates were significantly lowered. If federal lawmakers wish small issuers to have the same advantage over other tax-exempt municipal bond issuers after passage of TCJA, some changes will need to be made to the Internal Revenue Code to give small issuers an additional advantage when issuing tax-exempt debt.

Originality/value

No other empirical research to date has examined the impact of TCJA on bank-qualified bond issue interest cost.
Climate policy at the International Monetary Fund: No voice for the vulnerable?
Authors: Merling Lara , Forster Timon
Published: June 2024

The climate crisis prompted the International Monetary Fund (IMF), an international lender of last resort, to implement wholesale reforms to incorporate climate policy into its operations. At the IMF, selected countries from the Global North—historically the largest emitters of greenhouse gases—dominate decision‐making. This raises several questions. Can the Fund implement an ambitious and effective climate policy? How are climate‐vulnerable developing countries and their interests represented in everyday decision‐making at the institution? Drawing on scholarship on the political economy and legitimacy of international organizations, we focus on the formal distribution of decision‐making power within the IMF to evaluate the IMF's shift toward climate change. Our empirical analysis of the representation of 57 self‐identifying climate‐vulnerable developing countries (the V20) at the IMF and within its Executive Board shows that these countries, speaking for almost a third of the Fund's membership, command a vote share of merely 5.6%. Our assessment of the Climate Strategy adopted by the IMF amplifies equity concerns over its climate policies and further attests to the disregard of requests by developing countries. Barring meaningful governance reform to increase the voice and representation of climate‐vulnerable developing countries, the IMF's approach to addressing climate change is unlikely to translate into legitimate and effective climate policy.
Privacy decision‐making and the effects of privacy choice architecture: Experiments toward the design of behaviorally‐aware privacy regulation
Authors: Sprigman Christopher Jon , Tontrup Stephan
Published: June 2024

The current notice and choice privacy framework fails to empower individuals in effectively making their own privacy choices. In this Article we offer evidence from three novel experiments showing that at the core of this failure is a cognitive error. Notice and choice caters to a heuristic that people employ to make privacy decisions. This heuristic is meant to distinguish between a party's good or bad intent in face‐to‐face‐situations. In the online context, it distorts privacy decision‐making and leaves potential disclosers vulnerable to exploitation.

From our experimental evidence exploring the heuristic's effect, we conclude that privacy law must become more behaviorally aware. Specifically, privacy law must be redesigned to intervene in the cognitive mechanisms that keep individuals from making better privacy decisions. A behaviorally‐aware privacy regime must centralize, standardize and simplify the framework for making privacy choices.

To achieve these goals, we propose a master privacy template which requires consumers to define their privacy preferences in advance—doing so avoids presenting the consumer with a concrete counterparty, and this, in turn, prevents them from applying the intent heuristic and reduces many other biases that affect privacy decision‐making. Our data show that blocking the heuristic enables consumers to consider relevant privacy cues and be considerate of externalities their privacy decisions cause.

The master privacy template provides a much more effective platform for regulation. Through the master template the regulator can set the standard for automated communication between user clients and website interfaces, a facility which we expect to enhance enforcement and competition about privacy terms.
Numerically Optimized Ejector Geometry for Ejector Refrigeration Systems With Low-Global Warming Potential Working Fluids
Authors: Suresh Ronanki , Prakash Ranjith , Praveen Visakh , Datta Santanu Prasad
Published: June 2024

Recently, an ejector refrigeration system (ERS) has been a promising cooling strategy with waste heat utilization and minimization of power consumption by evading the compressor. However, analyzing the intricate flow structure inside the ejector and the corresponding coefficient of performance enhancement are major challenges of an ERS. The type of working fluid, design specifications, and working conditions significantly affect the ejector behavior. The environmental issues caused by the leakage of the most popular high-GWP refrigerant R134a divulge the need for low-GWP alternatives. Moreover, the effect of critical design specifications such as area ratio (AR) and nozzle exit position (NXP) for these alternatives is not explored yet. Therefore, five low-GWP alternates for R134a, namely R1234yf, R1243zf, R152a, R513a, and R440a, are tested numerically under wide-ranging operating conditions. In addition, the ejector performance for all refrigerants is examined for seven distinct ARs and five different NXPs. The effect of the refrigerant variant and NXP on the internal flow structures of the ejector is also analyzed. Besides, the study is extended to find the optimal NXP at various operating temperatures using R1234yf refrigerant. In most cases, the higher entrainment ratio (ER) is obtained with R1234yf and R1243zf, and the increase in AR has a positive effect on the ER. The impact of the NXP is higher at condenser temperature with minimal waste heat in the generator. Irrespective of the operating conditions for R1234yf, the optimum NXP is obtained as 10 mm, which is 1.67 times the constant-area mixing chamber diameter.
A Comprehensive Study on Optimizing 3D Printing Parameters for Improved Mechanical Properties of PLA and ABS Polymer
Authors: Shahan Habeeb Talha , Zainuddin Shaik , Ahmed G. M. Sayeed , Harry Richard
Published: June 2024

In recent years, due to the advent of 3D printing technology, a radical change has been noticed in the manufacturing of parts, particularly in the aerospace and automobile industries. It is hypothesized that by systematically varying the infill densities and raster angles in the 3D printing process, the mechanical properties of polymer composites can be improved significantly striking a balance between increased structural integrity, reduced material consumption and cost-efficiency. Therefore, in this work, we investigated the effect of different raster angles (0°, 45° and 90°) and infill percentages (25%–100%) on the flexural and thermo-mechanical properties of polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) composites processed with Fused Deposition Modeling (FDM) method. Results showed that the anisotropic behavior of both PLA and ABS samples is highly influenced by the raster angle, with 0° raster giving the highest flexure modulus. Additionally, the infill percentage significantly influenced the sample’s overall flexural strength. The PLA samples with a raster angle of 0° and a 50% infill showed a flexural strength of 167.72 MPa, while the ABS samples, also with a 0° raster angle but at a 75% infill, showed a flexural strength of 125.92 MPa. The results showed a significant enhancement in flexural strength and under optimized conditions. Similarly, the dynamic mechanical analysis (DMA) results showed the storage modulus and loss modulus properties of both PLA and ABS. Given the success of optimizing PLA and ABS, future research could explore integrating other materials or multi-material printing. These observations serve as a helpful starting point for creating guidelines and suggestions for improving 3D printing procedures leading to time and cost savings and expanding the potential of additive manufacturing in polymer and their fiber-reinforced composites.
Multifunctional Polyvinylidene Fluoride (PVDF)-Based Polymer, Copolymer, and Compo-Sites for Aerospace Applications: A Comprehensive Technical Review
Authors: Ahbab Nadia , Xu Tian-Bing
Published: June 2024

In this paper, we provide a comprehensive technical review on polyvinylidene fluoride (PVDF-based material processing and characterization as well as device developments for aeronautic and aerospace missions. We delve into the properties, advantages and disadvantages, and applications and device of PVDF-based materials and composites. The electromechanical properties of piezoelectric and pyroelectric PVDF materials as well as and operation principles of piezoelectric PVDF devices are discussed in detail. The summaries of PVDF-based devices for sensors, actuators, transducers, acoustic, communications, and energy harvesting and considering role of PVDF in structural health monitoring and Electro-magnetic interference (EMI) shielding which are important in aerospace and aeronautic are presented. Finally, we provide some guidelines on new material development, new functional device innovations, and effective applications for the aerospace community.
Adaptive-Stiffness Characteristics of Pneumatic Rotary Actuators for Folding Wingtips
Authors: Meyer Patrick , Sprengholz Moritz , Traub Hendrik , Hühne Christian
Published: June 2024

Folding wingtips address the challenges of high aspect ratio wings, such as airport conformity, increased wing root bending moment, and reduced aircraft maneuverability. The functionalities of free-flapping folding wingtips can be extended with multifunctional wingtip actuators that allow for active adjustment of the wingtip’s cant angle and hinge stiffness. The objective of this paper is the identification of governing factors influencing the adaptive-stiffness characteristics of pneumatic rotary actuators. The authors experimentally determine the characteristics of such a commercially available pneumatic rotary actuator and formulate analytical equations for actuator moment and stiffness as well as the wingtip’s natural frequencies. The actuator characteristics can be accurately described by an isobaric or adiabatic process, depending on the pneumatic setup. The pneumatic actuator exhibits zero stiffness in a pressure-regulated mode, whereas targeted adjustment of the actuator stiffness is possible by shutting off the mass flow into the actuator chambers. The formulated equations allow a detailed design of multifunctional wingtip actuators for application in highly efficient high aspect ratio aircraft. The findings of this study can be transferred to hydraulic rotary actuators, which would be required to achieve the necessary load-bearing capacity for application in larger transport aircraft.
Lattice Structure Design Using Machine Learning and Homogenization Approach
Authors: Mahdi Mohammed Abir , Crick Christopher , Zhao Wei
Published: June 2024

The homogenization approach is commonly used for lattice structure design by simplifying the modeling of complex geometric structures using simple solid elements in the finite element analysis. Homogenized material properties for solid elements are obtained through a Representative Volume Element (RVE). Several homogenization methods are available to determine effective material properties, including beam theory asymptotic homogenization (AH) and various others. In the current study, AH is chosen as it is widely utilized to assess lattice mechanical properties for a wide range of shapes. Although this approach is popular, it requires fine meshes when analyzing complex lattice geometries for computing material properties using finite element methods. Thus, it increases modeling complexity by including model preprocessing and generates a large order stiffness matrix, resulting in a computationally expensive analysis. Therefore, this study incorporated image processing instead of traditional mesh generation for calculating effective material properties. This methodology converts any image of a random-shaped RVE into a binary matrix to calculate its properties. In addition, this study introduced a Convolutional Neural Network (CNN) based on images of square lattice RVEs, which allows accurate and fast predictions of material properties. The developed model showed an error of 1.60% estimated on Mean Absolute Error (MAE) and 0.08% based on Mean Squared Error (MSE) in the training phase.
On the Impact of Including Gust and Flutter Constraints on the Design of Flying Wing Aircraft
Authors: Deslich Joshua , McHugh Kevin
Published: June 2024

Flying Wing Aircraft, while theoretically performant, suffer from a multitude of design challenges. These challenges include controllability and aeroelastic stability, among others. This paper introduces some early aeroelastic and control considerations into the conceptual/preliminary level design process and evaluates the impact these considerations have on the shape and weight of the design. Using the Equivalent Static Load method, gust responses from aeroelastic analyses are integrated into NASTRAN Solution 200, enabling the design of a wing structure sized with gust loads. Additionally, flutter constraints and maneuver trim conditions are implemented to determine aeroelastic stability and controllability. These NASTRAN-based optimizations are implemented as sub-optimizations in a Sequential Linear Programming algorithm, allowing for variations in the planform of the vehicle. Results indicate that the Equivalent Static Load method performs well and matches dynamic results. Optimization results indicate that the inclusion of the flutter constraint increases the weight of the vehicle, consistent with literature trends. Notably the inclusion of the gust response in addition to the flutter constraint drastically increases the weight of the vehicle as the aircraft must increase torsional stiffness via additional structural material to support the gust loads.
WrapToR Truss Joints: Path Planning for Three Dimensionally Wound Joint Structures With Manufacturing Constraints
Authors: Zhao Mengzhou , Macquart Terence , Woods Benjamin K. S.
Published: June 2024

Wrapped Tow Reinforced (WrapToR) truss structures are a unique class of truss beams fabricated from composite materials via a modified filament winding technique. While past studies have highlighted their weight advantages over traditional tubular composites, there’s growing attention towards their integration into Hierarchical Space Frames (HSFs), facilitating greater geometric flexibility for diverse applications. Central to this idea is the need for an efficient joining technology. This study introduces a concept employing a 3D version of the WrapToR winding method to generate optimal lattice joint designs. As designing winding paths for intricate joints involving varying numbers of trusses and angles is challenging, this paper presents a path planning algorithm underpinned by graph theory and manufacturing constraints. Primary considerations include tow continuity, geometric limitations, and issues arising from filament overlap and interference in 3D space. The proposed method involves identifying edges and nodes, prioritising them based on a dominance algorithm to minimise interference, and subdividing the problem into manageable sub-graphs. These are tackled using an adjusted graph theory technique, with the global solution being a combination of these sub-graphs, which can be wound in turn. To validate the methodology, specimens of 3-truss and 4-truss joints were path=planned and fabricated, underscoring the viability of the proposed approach.
Face value
Do I Know You?: A Faceblind Reporter’s Journey into the Science of Sight, Memory, and Imagination
Sadie Dingfelder
Little, Brown Spark, 2024. 304 pp.
Authors: Kemp Christopher
Published: June 2024

With candor and humor, a journalist offers an intimate portrait of faceblindness
Digitalization paving the ways for sustainable chemistry: switching on more green lights
Authors: Zuin Zeidler Vânia
Published: June 2024

The world is facing an interconnected crisis caused by a variety of factors including climate change, water scarcity, biodiversity loss, and chemical waste. One of most prominent factors is the exploitation of limited resources to convert them into chemical products based on the traditional linear approach. This has been provocatively described as
rubbish chemistry
, a “bad, old-school” system that needs to be revised globally. Representing one of the largest and most complex industrial sectors around the globe and accounting for $4 trillion USD in sales in 2019, the chemical industry generates fundamental components to produce agrochemicals, plastics, paints, adhesives, coatings, electronics, and pharmaceuticals. However, most of these chemicals are made
using oil and natural gas
, corresponding to 99% of the feedstocks for downstream organic chemical production.
Over 80% of the producing companies
assert that sustainability has become as important to them as revenue growth, and both increasingly depend on recent advancements in
digitalization
.
Guarding the walls: the multifaceted roles of Bce modules in cell envelope stress sensing and antimicrobial resistance
Authors: George Natasha L. , Bennett Ellen C. , Orlando Benjamin J.
Published: June 2024

Bacteria have developed diverse strategies for defending their cell envelopes from external threats. In Firmicutes, one widespread strategy is to use Bce modules—membrane protein complexes that unite a peptide-detoxifying ABC transporter with a stress response coordinating two-component system. These modules provide specific, front-line defense for a wide variety of antimicrobial peptides and small molecule antibiotics as well as coordinate responses for heat, acid, and oxidative stress. Because of these abilities, Bce modules play important roles in virulence and the development of antibiotic resistance in a variety of pathogens, including
Staphylococcus
,
Streptococcus
, and
Enterococcus
species. Despite their importance, Bce modules are still poorly understood, with scattered functional data in only a small number of species. In this review, we will discuss Bce module structure in light of recent cryo-electron microscopy structures of the
B. subtilis
BceABRS module and explore the common threads and variations-on-a-theme in Bce module mechanisms across species. We also highlight the many remaining questions about Bce module function. Understanding these multifunctional membrane complexes will enhance our understanding of bacterial stress sensing and may point toward new therapeutic targets for highly resistant pathogens.