bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal large-eddy simulation methods to model highly anisothermal and turbulent flows
Authors: David M. , Toutant A. , Bataille F.
Published: February 2023

Thermal large-eddy simulations (T-LES) of highly anisothermal and turbulent channel flows are assessed using direct numerical simulations (DNS). The investigated conditions are representative of solar receivers used in concentrated solar power towers. Four thermal operating conditions are considered. They aim to study several locations in the solar receiver. They are distinguished by different temperature profiles and thus different wall heat fluxes. The mean friction Reynolds number is close to 800 for all the simulations. The Navier–Stokes equations are solved under the low-Mach-number approximation. The nonlinear terms corresponding to the velocity–velocity and the velocity–temperature correlations are modeled. Functional, structural, and mixed models are investigated. An extension of the anisotropic minimum dissipation (AMD) model to compressible case and two-layer mixed models are proposed and assessed. Fourth-order and second-order centered schemes are tested for the discretization of the momentum convection term. First, a global assessment of 16T-LES approaches on mean quantities and correlations for three different meshes is performed in reference conditions. Then, three of the T-LES are selected for more detailed analyses. The mesh effect and the influence of the thermal conditions on the model accuracy are investigated. These detailed studies consist of the comparison of the relative error of the T-LES on mean quantities and correlations and the visualization of the normalized profiles as functions of the wall-normal distance. The results highlight the good agreement of two-layer mixed models consisting of the combination of the Bardina and the AMD models with the DNS for the three tested meshes.
Promoting the personal importation of therapeutic goods: recent legislative amendments to advertising regulations may impact consumer access and understanding
Authors: Rudge Christopher , Ghinea Narcyz
Published: February 2023

Objective The personal importation scheme is a legislative mechanism that allows health consumers to import unapproved medicines under certain conditions. This article analyses the legal and policy basis for the scheme and considers how reforms to advertising laws for therapeutic goods may restrict communications about it. The article represents the first published analysis of the personal importation scheme’s interaction with the communications of health professionals and buyer’s clubs. It considers how these communications may be affected by legal amendments, particularly where unapproved medicines may be accessed through the scheme. Methods An examination of Australian therapeutic goods law concerning the personal importation scheme was conducted, including both the historical law and recent regulatory reforms. Illustrative tables were prepared to identify scheme-related advertising that may contravene therapeutic goods law. Risk estimates were allocated to several new legal rules to indicate whether health professionals or buyer’s clubs would contravene these laws when promoting the scheme to health consumers for unapproved medicines. Results Representations made directly to the public by health practitioners or on buyer’s clubs websites about accessing unapproved therapeutic goods through the personal importation scheme are likely to contravene one or more advertising laws. Conclusions The Therapeutic Goods Administration has very strong powers to initiate compliance or enforcement action for advertising breaches in Australia for many promotional practices. Arguably, in the age of the internet and in the context of emerging expensive medicines, these powers should not be used to restrict health practitioners or buyer’s clubs from sharing information about the lawful personal importation scheme to health consumers in need. Nevertheless, the study finds that health practitioners who promote or refer to the availability of unapproved medicines through the personal importation scheme outside of a consultation are likely to contravene the law and may be subject to disciplinary or enforcement action.
Seven urgent actions to prevent the extinction of the critically endangered Leadbeater’s possum (Gymnobelideus leadbeateri)
Authors: Harley Dan
Published: February 2023

The conservation status of Leadbeater’s possum (Gymnobelideus leadbeateri) was upgraded to ‘Critically Endangered’ in 2015 following major impacts on populations and habitat arising from the ‘Black Saturday’ bushfires of 2009. This conservation listing was subsequently reviewed and retained in 2019. Despite this recognition of significant extinction risk, major gaps exist in the conservation strategy being applied, including the absence of a current recovery plan or meaningful recovery targets. The cumulative impacts and legacies on forest condition and hollow-bearing tree abundance from logging and bushfire pose the most significant threats to the species, and several studies indicate that the current reserve system is inadequate to protect viable populations. Seven high-level actions are recommended that should be implemented with urgency to prevent the extinction of this iconic, flagship species amidst increasing threats from climate change. Most significantly, this includes the rapid phase-out of logging within the species’ range as the highest priority action. Other urgent measures include re-formation of a recovery team to coordinate action implementation, provision of nest boxes and chainsaw hollows to increase den site availability, intensive population management and habitat restoration for the lowland population that now contains fewer than 40 individuals, and translocations to expand the area of occupancy in response to increasing risks from bushfire and climate change.
Combining acoustic localisation and high-resolution land cover classification to study predator vocalisation behaviour
Authors: Bru Elisabeth , Smith Bethany R. , Butkiewicz Hannah , Fontaine Amy C. , Dassow Angela , Owens Jessica L. , Root-Gutteridge Holly , Schindler Loretta , Kershenbaum Arik
Published: February 2023

Context The ecology of cryptic animals is difficult to study without invasive tagging approaches or labour-intensive field surveys. Acoustic localisation provides an effective way to locate vocalising animals using acoustic recorders. Combining this with land cover classification gives new insight into wild animal behaviour using non-invasive tools. Aims This study aims to demonstrate how acoustic localisation – combined with high-resolution land cover classification – permits the study of the ecology of vocalising animals in the wild. We illustrate this technique by investigating the effect of land cover and distances to anthropogenic features on coyote and wolf vocal behaviour. Methods We collected recordings over 13 days in Wisconsin, USA, and triangulated vocalising animals’ locations using acoustic localisation. We then mapped these locations onto land cover using a high-resolution land cover map we produced for the area. Key results Neither coyotes nor wolves vocalised more in one habitat type over another. Coyotes vocalised significantly closer to all human features than expected by chance, whereas wolves vocalised significantly further away. When vocalising closer to human features, coyotes selected forests but wolves showed no habitat preference. Conclusions This novel combination of two sophisticated, autonomous sensing-driven tools permits us to examine animal land use and behavioural ecology using passive sensors, with the aim of drawing ecologically important conclusions. Implications We envisage that this method can be used at larger scales to aid monitoring of vocally active animals across landscapes. Firstly, it permits us to characterise habitat use while vocalising, which is an essential behaviour for many species. Furthermore, if combined with additional knowledge of how a species’ habitat selection while vocalising relates to its general habitat use, this method could permit the derivation of future conclusions on prevailing landscape use. In summary, this study demonstrates the potential of integrating acoustic localisation with land cover classification in ecological research.
Applying a versatile, comprehensive, attribute-based waterhole classification scheme to ecosystem-based management challenges
Authors: Glanville K. , Perry J. , Ryan T. , Ronan M. , Zivec P.
Published: February 2023

Context Understanding habitat suitability for feral animals across a landscape is important for conservation planning because the spatial and temporal availability of water provides critical limits to native biodiversity and the processes that threaten it. Previous attempts to support management actions on feral pig populations through predictions of population abundance, distribution and seasonal resource constraints have been confounded by a lack of knowledge, classification and mapping of waterholes – which are critical to their survival. Aims In this paper, we aimed to apply a waterhole classification scheme for feral pig management to address gaps in our understanding of water and food availability through space and time, at scales relevant to feral animal movement and resource use. Methods We utilise an attribute-based waterhole classification scheme for ecosystem-based management by defining a waterhole typology of feral pig habitat suitability and applying it spatially. Key results Five attributes (water permanence, predictability of inundation, oceanic influence, dominant vegetation and shading) reflect many of the critical requirements for feral pig habitat in northern Australia. The attributes directly relate to the environmental constraints that exert population and behavioural pressure on feral pigs. These attributes were applied spatially in a specific hierarchy to group waterholes into 21 types. Conclusions A waterhole typology that characterises within the context of their suitability for feral pig populations is foundational for systematic adaptive management and monitoring programs that aim to reduce the impact of threatening processes on freshwater ecosystems. Implications Refining the mapping of important feral pig habitat variables (water and food) will greatly improve modelling approaches that aim to support data-driven management approaches, such as connectivity analysis and estimating population dynamics to inform culling programs. Here we demonstrate a significant increase in overlap with known feral pig distributions using a much smaller mapped effective management area when compared with previous best available spatial products.
Habitat structure facilitates coexistence of native and invasive mesopredators in an Australian tropical savanna
Authors: Trewella Gavin J. , Cremona Teigan , Nevard Harry , Murphy Brett P.
Published: February 2023

Context The introduction of the cat (Felis catus) to Australia has been a key driver of the decline and extinction of the continent’s endemic mammals. Currently, there is no clear long-term solution to controlling feral populations of cats at a landscape scale. As such, understanding how environmental conditions and habitat attributes can mediate the coexistence between introduced predators and native mammals can improve management outcomes for threatened species. Aim We sought to compare the differences in habitat use by feral cats and a remnant population of the endangered northern quoll (Dasyurus hallucatus) to understand what environmental variables allow these two mesopredators to coexist in tropical savanna of Cape York Peninsula, Queensland. Methods We deployed grids of motion-activated cameras three times per year over a 3-year period, across Eucalyptus tetrodonta-dominated plateaux known to be inhabited by feral cats and northern quolls. We modelled the spatial variation in the frequencies of detection of feral cats and northern quolls (referred to as ‘habitat use’), as a function of biotic and abiotic environmental variables by using a generalised linear model for consistent variables and a generalised linear mixed-effect model for fluctuating variables. Key results Habitat use by feral cats was most frequent in areas with high fire frequencies and low tree basal area, whereas habitat use by northern quolls was most frequent in areas of high basal area of E. tetrodonta (a commonly used den tree species), topographic ruggedness, and long-unburnt savanna. Conclusions Frequent fires in tropical savanna promote habitat use by feral cats and can result in a reduction of critical habitat for northern quolls. Implications We postulate that remnant populations of northern quolls on Cape York Peninsula occur in less frequently burnt refugia, primarily on top of plateaux that support high-biomass tropical savanna dominated by E. tetrodonta. Our findings highlighted that threatened mammals can persist alongside introduced predators in tropical savanna but are dependent on the maintenance of structurally complex habitat.
A convergent subcortical signature to explain the common efficacy of subthalamic and pallidal deep brain stimulation
Authors: Steiner Leon A , Milosevic Luka
Published: February 2023

This scientific commentary refers to ‘Globus pallidus internus deep brain stimulation evokes resonant neural activity in Parkinson’s disease’, by Johnson et al. (https://doi.org/10.1093/braincomms/fcad025).
Infection-Induced Immunity Is Associated With Protection Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Decreased Infectivity
Authors: Frutos Aaron M , Kuan Guillermina , Lopez Roger , Ojeda Sergio , Shotwell Abigail , Sanchez Nery , Saborio Saira , Plazaola Miguel , Barilla Carlos , Kenah Eben , Balmaseda Angel , Gordon Aubree
Published: February 2023

Background

The impact of infection-induced immunity on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission has not been well established. Here we estimate the effects of prior infection induced immunity in adults and children on SARS-CoV-2 transmission in households.

Methods

We conducted a household cohort study from March 2020-November 2022 in Managua, Nicaragua; following a housheold SARS-CoV-2 infection, household members are closely monitored for infection. We estimate the association of time period, age, symptoms, and prior infection with secondary attack risk.

Results

Overall, transmission occurred in 70.2% of households, 40.9% of household contacts were infected, and the secondary attack risk ranged from 8.1% to 13.9% depending on the time period. Symptomatic infected individuals were more infectious (rate ratio [RR] 21.2, 95% confidence interval [CI]: 7.4–60.7) and participants with a prior infection were half as likely to be infected compared to naïve individuals (RR 0.52, 95% CI:.38–.70). In models stratified by age, prior infection was associated with decreased infectivity in adults and adolescents (secondary attack risk [SAR] 12.3, 95% CI: 10.3, 14.8 vs 17.5, 95% CI: 14.8, 20.7). However, although young children were less likely to transmit, neither prior infection nor symptom presentation was associated with infectivity. During the Omicron era, infection-induced immunity remained protective against infection.

Conclusions

Infection-induced immunity is associated with decreased infectivity for adults and adolescents. Although young children are less infectious, prior infection and asymptomatic presentation did not reduce their infectivity as was seen in adults. As SARS-CoV-2 transitions to endemicity, children may become more important in transmission dynamics.
Adherence to Antimicrobial Prophylaxis Guidelines for Elective Surgeries Across 825 US Hospitals, 2019–2020
Authors: Cabral Stephanie M , Harris Anthony D , Cosgrove Sara E , Magder Laurence S , Tamma Pranita D , Goodman Katherine E
Published: February 2023

Background

There are limited US data assessing adherence to surgical antimicrobial prophylaxis guidelines, particularly across a large, nationwide sample. Moreover, commonly prescribed inappropriate antimicrobial prophylaxis regimens remain unknown, hindering improvement initiatives.

Methods

We conducted a retrospective cohort study of adults who underwent elective craniotomy, hip replacement, knee replacement, spinal procedure, or hernia repair in 2019–2020 at hospitals in the PINC AI (Premier) Healthcare Database. We evaluated adherence of prophylaxis regimens, with respect to antimicrobial agents endorsed in the American Society of Health-System Pharmacist guidelines, accounting for patient antibiotic allergy and methicillin-resistant Staphylococcus aureus colonization status. We used multivariable logistic regression with random effects by hospital to evaluate associations between patient, procedural, and hospital characteristics and guideline adherence.

Results

Across 825 hospitals and 521 091 inpatient elective surgeries, 308 760 (59%) were adherent to prophylaxis guidelines. In adjusted analysis, adherence varied significantly by US Census division (adjusted OR [aOR] range: .61–1.61) and was significantly lower in 2020 compared with 2019 (aOR: .92; 95% CI: .91–.94; P < .001). The most common reason for nonadherence was unnecessary vancomycin use. In a post hoc analysis, controlling for patient age, comorbidities, other nephrotoxic agent use, and patient and procedure characteristics, patients receiving cefazolin plus vancomycin had 19% higher odds of acute kidney injury (AKI) compared with patients receiving cefazolin alone (aOR: 1.19; 95% CI: 1.11–1.27; P < .001).

Conclusions

Adherence to antimicrobial prophylaxis guidelines remains suboptimal, largely driven by unnecessary vancomycin use, which may increase the risk of AKI. Adherence decreased in the first year of the COVID-19 pandemic.
The genetic structure within a single tree is determined by the behavior of the stem cells in the meristem
Authors: Iwasa Yoh , Tomimoto Sou , Satake Akiko
Published: February 2023

Genomic sequencing revealed that somatic mutations cause a genetic differentiation of the cells in a single tree. We studied a mathematical model for stem cell proliferation in the shoot apical meristem (SAM). We evaluated the phylogenetic distance between cells sampled from different portions of a shoot, indicating their genetic difference due to mutations accumulated during shoot elongation. The plant tissue has cell walls that suppress the exchange of location between cells. This leads to the genetic differentiation of cells according to the angle around the shoot and a larger genetic variance among cells in the body. The assumptions are as follows: stem cells in the SAM normally undergo asymmetric cell division, producing successor stem cells and differentiated cells. Occasionally, a stem cell fails to leave its successor stem cell and the vacancy is filled by the duplication of one of the nearest neighbor stem cells. A mathematical analysis revealed the following: the genetic diversity of cells sampled at the same position along the shoot increases with the distance from the base of the shoot. Stem cells hold a larger variation if they are replaced only by the nearest neighbors. The coalescent length between two cells increases not only with the difference in the position along the shoot but also in the angle around the shoot axis. The dynamics of stem cells at the SAM determine the genetic pattern of the entire shoot.
The authoritarian narrator: China's power projection and its reception in the Gulf
Authors: Gurol Julia
Published: February 2023

This article argues that transregional communication mechanisms and the diffusion of narratives are important co-drivers towards autocratization. Offering a look beyond the ‘material’ in the study of global authoritarianism, it makes two conceptual arguments. It shows show transregional authoritarian practices are often discursively reinforced. Moreover, it demonstrates how narratives and their transregional diffusion are a form of authoritarian image management and a tool for fostering authoritarian stability. Departing from the basic assumption of authoritarian diffusion, the article is guided by two questions: which narratives of supremacy are used by the Chinese government in the context of the pandemic? And how are these narratives received, reproduced and contested in the Gulf? Based on a qualitative analysis of more than 3,000 media outlets (March–May 2020) from China and the Gulf region, the article shows how China strategically promotes authoritarian narratives regarding its international role, by telling stories of supremacy and heroism and by narratively conjuring a new world order. Moreover, it shows how the Chinese narratives are diffused to Iran, Saudi-Arabia, the United Arab Emirates and Qatar and depicts the different patterns of reception, reproduction and contestation.
The Iraq War 20 years on: towards a new regional architecture
Authors: Fawcett Louise
Published: February 2023

The consequences of the Iraq War of 2003 continue to reverberate throughout the Middle East and wider world in multiple, if still underacknowledged, ways. Though subsequent regional developments have taken centre stage—notably those surrounding the Arab Uprisings and the subsequent civil wars and interventions in Libya, Syria and Yemen—the effects of the Iraq War remain powerfully present. A watershed event, it has generated major and irreversible changes at the international and regional level. It has empowered certain states and actors, and weakened others— notably Iraq itself—but its impact on both the regional and wider global security landscape cannot be underestimated. Arguing that the events surrounding the Iraq War and its outcome constituted a ‘critical juncture’, or major inflexion point in regional order, this article examines three interdependent features of the changing regional architecture. The first relates to the region's international alignments; the second to its balance of power; and the third to the changing institutional environment, which challenges and redefines the very boundaries of the Middle East.
A qualitative improvement program for minimally invasive mitral surgery: technical advancements ameliorate outcome and operative times
Authors: Gollmann-Tepeköylü Can , Nägele Felix , Höfer Daniel , Holfeld Johannes , Hirsch Jakob , Oezpeker Cenk Ulvi , Ruttmann-Ulmer Elfriede , Kilo Juliane , Hangler Herbert , Müller Ludwig , Grimm Michael , Bonaros Nikolaos
Published: February 2023

OBJECTIVES

Minimally invasive mitral valve surgery (MIMVS) has evolved over the last 2 decades. The aim of the study was to identify the impact of era and technical improvements on perioperative outcome after MIMVS.

METHODS

A tota of 1000 patients (mean age: 60.8 ± 12.7 years, 60.3% male) underwent video-assisted or totally endoscopic MIMVS between 2001 and 2020 in a single institution. Three technical modalities were introduced during the observed period: (i) 3D visualization, (ii) use of premeasured artificial chordae (PTFE loops) and (iii) preoperative CT scans. Comparisons were made before and after the introduction of technical improvements.

RESULTS

A total of 741 patients underwent isolated mitral valve (MV) procedure, whereas 259 received concomitant procedures. These consisted of tricuspid valve repair (208), left atrium ablation (145) and persistent foramen ovale or atrial septum defect (ASD) closure (172). The aetiology was degenerative in 738 (73.8%) patients and functional in 101 patients (10.1%). A total of 900 patients received MV repair (90%), and 100 patients (10%) underwent MV replacement. Perioperative survival was 99.1%, and periprocedural success 93.5% with a periprocedural safety of 96.3%. Improvement in periprocedural safety attributed to the lower rates of postoperative low output (P = 0.025) and less reoperations for bleeding (P < 0.001). 3D visualization improved cross-clamp (P = 0.001) but not cardiopulmonary bypass times. The use of loops and preoperative CT scan both had no impact on periprocedural success or safety but improved cardiopulmonary bypass and cross-clamp times (both P < 0.001).

CONCLUSIONS

Increased surgical experience improves safety in MIMVS. Technical improvements are related to increased operative success and decreased operative times in patients undergoing MIMVS.
Current trends in managing TMJ ankylosis in children—summing it up with a case report
Authors: Prabhu Namdeo , Issrani Rakhi , Ganji Kiran Kumar
Published: February 2023

Temporomandibular joint (TMJ) ankylosis involves fusion of the mandibular condyle to the base of the skull. The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and a high incidence of recurrence. The experience of managing one such case is reported in light of a review of the literature on this condition. This report describes a case of a 7-year-old girl with inability to open her mouth, diagnosed with unilateral right bony TMJ ankylosis. Key management principles included adequate removal of the ankylotic mass, gap arthroplasty with interpositional temporalis myofascial grafting and post-operative physiotherapy. The patient maintains a satisfactory maximal incisal opening till the present day. A detailed history, clinical and functional examination, radiographic examination facilitating correct diagnosis followed by immediate surgical intervention, and physiotherapy might be beneficial to restore physical, psychological and emotional health of the child patient with TMJ ankylosis.
About the loss of a primordial atmosphere of super-Earths by planetesimal impacts
Authors: Lozovsky Michael , Prialnik Dina , Podolak Morris
Published: February 2023

We consider planets composed of water ice and rock, located far from a central star. In an earlier study, computing the growth of planets by continuous accretion, we found that a large fraction of the ice evaporates upon accretion, creating a water vapor atmosphere. Here, we consider accretion as a discrete series of planetesimal impacts (of the order of 108), at the same time-dependent accretion rate, and investigate the fate of the vapor, as a result of its interaction with the accreting planetesimals. We find that a large fraction of the vapor escapes. The remaining fraction may form an outer layer of ice after the termination of accretion and cooling of the surface. The escaped water mass may significantly alter the ice-to-rock ratio of the planet. We investigate the effect of different choices of parameters such as the ice-to-rock ratio, the planetesimal size distribution, and the impact velocities. We find that the planetesimal size distribution has a negligible effect and explain why. By contrast, the ice-to-rock ratio and impact velocities affect the fraction of retained water masses considerably.
Effectiveness and Safety of Bictegravir/Emtricitabine/Tenofovir Alafenamide in Patients With HIV-1 Infection and Ongoing Substance Use Disorder: The BASE Study
Authors: Havens Joshua P , Bares Sara H , Lyden Elizabeth , Podany Anthony T , Scarsi Kimberly K , Fadul Nada , Swindells Susan
Published: February 2023

Background

People with human immunodeficiency virus (HIV) and substance use disorder (PWH/SUD) are at higher risk of nonadherence to antiretroviral therapy. Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) exhibits high rates of efficacy with a favorable adverse event profile. The BASE study (NCT03998176) is a phase 4, single-arm study evaluating the effectiveness and safety of B/F/TAF among PWH/SUD.

Methods

Viremic (HIV RNA >1000 copies/mL) PWH/SUD initiated B/F/TAF once daily for 48 weeks (W). The primary endpoint was proportion of participants with HIV RNA <50 copies/mL at W24. Secondary endpoints were proportion of participants with HIV-1 RNA <50 copies/mL at W48, safety, B/F/TAF adherence (dried blood spot [DBS] concentrations of emtricitabine triphosphate and tenofovir diphosphate [TFV-DP]), substance use (NIDA-ASSIST), and quality of life (SF-12).

Results

Forty-three participants were enrolled; 95% reported methamphetamine use. Median age was 38 (range, 21–62) years; 21% were female, 81% White, 14% Black, and 16% Hispanic. Thirty-two (74%) and 21 (49%) participants had HIV RNA <50 copies/mL (intention-to-treat) at W24 and W48, respectively. Seven participants (16%) experienced confirmed virologic failure through W48; 1 developed emergent drug resistance (M184V). Fifteen participants (35%) experienced grade ≥3 adverse events. Five participants (12%) reported suicidal ideation; none resulted in discontinuation. Median DBS concentrations were representative of 5–6 doses/week (TFV-DP, 1603 fmol/punches). NIDA-ASSIST scores declined from baseline to W48 with methamphetamine use decreasing most (−7.9 points; −29%), and SF-12 physical/mental scores increased 1.2 and 7.6 points, respectively.

Conclusions

B/F/TAF among a high-risk population of PWH/SUD resulted in an initial 72% viral suppression rate at W24 before dropping to 49% at W48 as retention declined. One participant developed emergent drug resistance (M184V).
High cyclic electron transfer via the PGR5 pathway in the absence of photosynthetic control
Authors: Degen Gustaf E , Jackson Philip J , Proctor Matthew S , Zoulias Nicholas , Casson Stuart A , Johnson Matthew P
Published: February 2023

The light reactions of photosynthesis couple electron and proton transfers across the thylakoid membrane, generating NADPH, and proton motive force (pmf) that powers the endergonic synthesis of ATP by ATP synthase. ATP and NADPH are required for CO2 fixation into carbohydrates by the Calvin–Benson–Bassham cycle. The dominant ΔpH component of the pmf also plays a photoprotective role in regulating photosystem II light harvesting efficiency through nonphotochemical quenching (NPQ) and photosynthetic control via electron transfer from cytochrome b6f (cytb6f) to photosystem I. ΔpH can be adjusted by increasing the proton influx into the thylakoid lumen via upregulation of cyclic electron transfer (CET) or decreasing proton efflux via downregulation of ATP synthase conductivity (gH+). The interplay and relative contributions of these two elements of ΔpH control to photoprotection are not well understood. Here, we showed that an Arabidopsis (Arabidopsis thaliana) ATP synthase mutant hunger for oxygen in photosynthetic transfer reaction 2 (hope2) with 40% higher proton efflux has supercharged CET. Double crosses of hope2 with the CET-deficient proton gradient regulation 5 and ndh-like photosynthetic complex I lines revealed that PROTON GRADIENT REGULATION 5 (PGR5)-dependent CET is the major pathway contributing to higher proton influx. PGR5-dependent CET allowed hope2 to maintain wild-type levels of ΔpH, CO2 fixation and NPQ, however photosynthetic control remained absent and PSI was prone to photoinhibition. Therefore, high CET in the absence of ATP synthase regulation is insufficient for PSI photoprotection.
Differential Susceptibility of Two Citrullus amarus Pollenizer Watermelons to Five Species of Pythium and Globisporangium
Authors: Keinath Anthony P. , Colburn G. Curtis , Yang Xiao
Published: February 2023

Pollenizer watermelon (Citrullus amarus) must be planted alongside triploid watermelon cultivars to provide a source of pollen. Early season death of pollenizer watermelon cultivars SP-6 and SP-7 was observed in a research field in Charleston County, SC, in April 2022, 3 to 4 weeks after transplanting. Disease incidence was 15 and 12% for the two cultivars, respectively. Two species of Pythium (P. myriotylum and P. aphanidermatum) and three species of Globisporangium (G. ultimum, G. irregulare, and G. spinosum) were recovered from 13 of 17 plants cultured and identified based on the sequences of the cytochrome c oxidase subunit I gene. Pythium spp. were recovered from both cultivars, while Globisporangium spp. were recovered only from ‘SP-7’. In pathogenicity tests, ‘SP-7’ had lower area under the disease progress curve (AUDPC) values than ‘SP-6’ with one isolate each of four species and lower AUDPC values than seedless watermelon ‘Estrella’ with one isolate each of two species. Mean AUDPC values did not differ between ‘Estrella’ and ‘SP-6’ with any isolate. AUDPC values were greater with G. ultimum on all three cultivars than with one isolate of G. spinosum and both isolates of P. myriotylum and P. aphanidermatum. Susceptibility of the new cultivar SP-7 to Pythium and Globisporangium spp. differs from susceptibility of ‘SP-6’. These results will help growers choose which pollenizer cultivar to plant.
Defining Fungicide Resistance Mechanisms in the Corynespora cassiicola Population from Mississippi Soybean
Authors: Wang Xiaopeng , Aboughanem-Sabanadzovic Nina , Sabanadzovic Sead , Tomaso-Peterson Maria , Wilkerson Tessie H. , Allen Tom W.
Published: February 2023

Target spot, caused by Corynespora cassiicola, is a common lower canopy soybean disease in the southern United States. Recently, target spot has resurged in importance especially following the identification of resistance to the quinone outside inhibitor (QoI) fungicides. As a result, a survey of C. cassiicola from soybean throughout Mississippi began in 2018. A total of 819 C. cassiicola monoconidial isolates were obtained from 228 fields in 75 counties. The molecular mechanism of QoI resistance was determined, which resulted from an amino acid substitution from glycine (G) to alanine (A) at position 143 using a PCR-RFLP method and comparing nucleotide sequences of the cytochrome b gene. Five previously defined geographic regions were used to present the distribution of the G143A substitution and included the Capital, Coast, Delta, Hills, and Pines. The Capital had the greatest proportion of G143A-containing isolates (95.0%), followed by the Coast (92.9%), Delta (89.8%), Pines (78.8%), and Hills (69.4%). In all, 85.8% of the C. cassiicola isolates carried the G143A substitution. In addition, the effective fungicide concentration (EC50) of randomly selected C. cassiicola isolates to azoxystrobin was used to characterize isolates as resistant (n = 14) (based on the presence of the G143A substitution and EC50 values >52 μg/ml) or sensitive (n = 11) (based on the absence of the G143A substitution and EC50 values <46 μg/ml). The EC50 values varied among isolates (P < 0.0001), with QoI-sensitive isolates exhibiting lower EC50 values than QoI-resistant isolates. The current study revealed that a reduction in sensitivity to QoI fungicides has likely resulted based on the percentage of C. cassiicola isolates containing the G143A substitution identified in Mississippi.
Abscisic Acid Is Involved in the Resistance Response of Arabidopsis thaliana Against Meloidogyne paranaensis
Authors: Yop Geovana de Souza , Gair Luiz Henrique Voigt , da Silva Victoria Stern , Machado Andressa Cristina Zamboni , Santiago Débora Cristina , Tomaz Juarez Pires
Published: February 2023

Abscisic acid (ABA) is a classical hormone involved in the plant defense against abiotic stresses, especially drought. However, its role in the defense response against biotic stresses is controversial: it can induce resistance to some pathogens but can also increase the susceptibility to other pathogens. Information regarding the effect of ABA on the relationship between plants and sedentary phytonematodes, such as Meloidogyne paranaensis, is scarce. In this study, we found that ABA changed the susceptibility level of Arabidopsis thaliana against M. paranaensis. The population of M. paranaensis was reduced by 58.3% with the exogenous application of ABA 24 h before the nematode inoculation, which demonstrated that ABA plays an important role in the preinfectional defense of A. thaliana against M. paranaensis. The increase in the nematode population density in the ABA biosynthesis mutant, aba2-1, corroborated the results observed with the exogenous application of ABA. The phytohormone did not show nematicide or nematostatic effects on M. paranaensis juveniles in in vitro tests, indicating that the response is linked to intrinsic plant factors, which was corroborated by the decrease in the number of nematodes in the abi4-1 mutant. This reduction indicates that the gene expression regulation by transcript factors is possibly related to regulatory cascades mediated by ABA in the response of A. thaliana against M. paranaensis.
Resistance and Tolerance Screening of Spring Wheat Cultivars to Cereal Cyst Nematode (Heterodera avenae) in Southeastern Idaho
Authors: Ensafi Pooria , Smiley Richard W. , Moll Margaret T. , Rashed Arash , Jackson Chad A. , Marshall Juliet M.
Published: February 2023

Increased populations of Heterodera avenae in southeastern Idaho are associated with increased planting of susceptible cereal cultivars and lack of crop rotation. Identifying high-yield, resistant spring wheat cultivars with tolerance requires testing new genotypes and susceptibility assessments of marketed cultivars. We conducted two experiments to determine whether cultivars with putative resistance could maintain acceptable yield in the presence of H. avenae. We also evaluated the tolerance response in relation to previously tested cultivars. Seven spring wheat cultivars were planted in two irrigated commercial fields that were naturally infested with high populations of H. avenae. Measures of resistance, tolerance, and grain yield were assessed in aldicarb-treated versus nontreated plots. In aldicarb-treated plots in both years, grain yield of the susceptible cultivars Snow Crest, WestBred 936, WB9411, Patwin-515, and WB9668 was significantly increased. The expected yield increase with aldicarb was limited for the moderately susceptible Expresso due to water stress. ‘WB-Rockland’, carrying the Cre5 resistance gene, maintained its standard yield, while none of the other cultivars in the experiment showed resistance or tolerance. Our results indicated that aldicarb improves wheat grain yield in irrigated crop production systems, and although removed from the market, it is effective and has utility for research. The results also support the hypothesis that high yield susceptible cultivars can mask the effect of H. avenae on grain yield when managed appropriately.
A Quantitative PCR Method to Detect the Tomato Corky Root Rot Pathogens, Pseudopyrenochaeta lycopersici and P. terrestris
Authors: Testen Anna L. , Shaw R. Scott , Rotondo Francesca , Moodispaw Margaret R. , Miller Sally A.
Published: February 2023

Corky root rot is an important disease in tomato production systems and is caused by Pseudopyrenochaeta terrestris and P. lycopersici (formerly Pyrenochaeta lycopersici Types 1 and 2, respectively). The corky root rot pathogens are slow growing and difficult to isolate and quantify in soil and plant tissue. A multiplex hydrolysis probe-based qPCR assay was designed to allow for simultaneous detection and quantification of P. lycopersici and P. terrestris with a competitive internal control to indicate if qPCR inhibitors are present. Single species and multiplex assays for Pseudopyrenochaeta spp. detected DNA levels above 0.013 pg of DNA per reaction. These highly specific assays had no nontarget amplification of other fungal and oomycete pathogens or rhizosphere-associated fungi of tomatoes that were tested. This assay can be used to quantify Pseudopyrenochaeta populations in roots and soils in tomato production systems to better determine the impacts of disease management strategies on Pseudopyrenochaeta spp. and provides a tool to study the biology of Pseudopyrenochaeta spp.
Genome Resource of Streptomyces atratus PY-1, a Broad-Spectrum Antimicrobial Strain in Particular Antagonistic Against Plasmopara viticola
Authors: Pei Xue , Liu Xiaozhou , Zang Chaoqun , Yu Shuyi , Xie Jinhui , Lin Ying , Liang Bingbing , Wu Xuehong , Liang Chunhao
Published: February 2023

Streptomyces atratus PY-1 exhibited promising antimicrobial properties; in particular, it is highly inhibitory to Plasmopara viticola, which causes downy mildew of grape. It is very necessary to carry out systematic and in-depth research on the PY-1 strain for the improvement, application, and promotion of biocontrol agents. The PY-1 genome was fully sequenced and assembled. We present the draft genome sequence of PY-1, with a size of 9, 254, and 781 bp. Preliminary analysis on the PY-1 genome sequence shows that at least 35 gene clusters are involved in the biosynthesis of polyketides, terpenes, and nonribosomally synthesized peptides.
Identification and Molecular Mapping of the Gene YrFL in Wheat Cultivar Flanders with Durable Resistance to Stripe Rust
Authors: Wu Caijuan , Ma Kangjie , Chen Wenbin , Li Jianhao , Liu Mingjie , Cheng Peng , Wang Baotong , Li Qiang
Published: February 2023

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most severe diseases of wheat (Triticum aestivum L.) worldwide. Identification and characterization of resistance genes is advantageous to cultivating wheat varieties with durable resistance, which is the most economic and effective strategy to control stripe rust. Flanders, a common wheat cultivar released in France in 1986, confers effective resistance to stripe rust both at the seedling and adult plant stages. To elucidate the genetic basis of resistance in Flanders, F1, F2, and F2:3 generations derived from the cross Mingxian169 × Flanders were evaluated with the most prevalent Chinese Pst race CYR33 at the seedling stage. Inheritance analysis showed that the stripe rust resistance of Flanders was controlled by a single dominant gene, temporarily designated as YrFL. Bulked segregant analysis (BSA) combined with a wheat 660K single-nucleotide polymorphism (SNP) array indicated that polymorphic SNP markers were mainly located in the 0 to 150 Mb on wheat chromosome 5A. One hundred and eleven kompetitive allele-specific PCR (KASP) and 39 simple sequence repeat (SSR) markers on chromosome 5A were used to locate the YrFL. Linkage analysis mapped YrFL with 19 KASP and three SSR markers on wheat chromosome 5AS, and the genetic distances of the closest flanking markers AX108925494 and Xbarc56 to YrFL were 0.6 and 2.0 cM, respectively. Chromosome location, resistance characterization, and molecular marker positions indicated that YrFL is likely a novel stripe rust resistance gene on wheat chromosome 5AS and could be pyramided with other resistance genes to improve resistance in wheat breeding programs.
Insights into the Aggressiveness of the Emerging North American Population 3 (NA3) of Fusarium graminearum
Authors: Laraba Imane , Ward Todd J. , Cuperlovic-Culf Miroslava , Azimi Hilda , Xi Pengcheng , McCormick Susan P. , Hay William T. , Hao Guixia , Vaughan Martha M.
Published: February 2023

In the United States and Canada, Fusarium graminearum (Fg) is the predominant etiological agent of Fusarium head blight (FHB), an economically devastating fungal disease of wheat and other small grains. Besides yield losses, FHB leads to grain contamination with trichothecene mycotoxins that are harmful to plant, human, and livestock health. Three genetic North American populations of Fg, differing in their predominant trichothecene chemotype (i.e., NA1/15ADON, NA2/3ADON, and NA3/NX-2), have been identified. To improve our understanding of the newly discovered population NA3 and how population-level diversity influences FHB outcomes, we inoculated heads of the moderately resistant wheat cultivar Alsen with 15 representative strains from each population and evaluated disease progression, mycotoxin accumulation, and mycotoxin production per unit Fg biomass. Additionally, we evaluated population-specific differences in induced host defense responses. The NA3 population was significantly less aggressive than the NA1 and NA2 populations but posed a similar mycotoxigenic potential. Multiomics analyses revealed patterns in mycotoxin production per unit Fg biomass, expression of Fg aggressiveness-associated genes, and host defense responses that did not always correlate with the NA3-specific severity difference. Our comparative disease assay of NA3/NX-2 and admixed NA1/NX-2 strains indicated that the reduced NA3 aggressiveness is not due solely to the NX-2 chemotype. Notably, the NA1 and NA2 populations did not show a significant advantage over NA3 in perithecia production, a fitness-related trait. Together, our data highlight that the disease outcomes were not due to mycotoxin production or host defense alone, indicating that other virulence factors and/or host defense mechanisms are likely involved.
Evaluating Options to Increase the Efficacy of Biocontrol Agents for the Management of Pantoea spp. Under Field Conditions
Authors: Koirala Santosh , Myers Brendon , Shin Gi Yoon , Gitaitis Ron , Kvitko Brian H. , Dutta Bhabesh
Published: February 2023

Center rot of onion is caused by a complex of plant pathogenic Pantoea species, which can lead to significant yield losses in the field and during storage. Conventional growers use foliar protectants such as a mixture of copper bactericides and an ethylene-bis-dithiocarbamate (EBDC) fungicide to manage the disease; however, organic growers have limited management options besides copper-protectants. Biocontrol agents (BCAs) provide an alternative; however, their efficacy could be compromised due in part to their inability to colonize the foliage. We hypothesized that pretreatment with peroxide (OxiDate 2.0: a.i., hydrogen peroxide and peroxyacetic acid) enhances the colonizing ability of the subsequently applied BCAs, leading to effective center rot management. Field trials were conducted in 2020 and 2021 to assess the efficacy of peroxide, BCAs (Serenade ASO: Bacillus subtilis and BlightBan: Pseudomonas fluorescens), and an insecticide program (tank mix of spinosad and neem oil) to manage center rot. We observed no significant difference in foliar area under the disease progress curve (AUDPC) between the peroxide pretreated P. fluorescens plots and only P. fluorescens-treated plots in 2020 and 2021. Peroxide pretreatment before B. subtilis application significantly reduced the foliar AUDPC as compared with the stand-alone B. subtilis treatment in 2020; however, no such difference was observed in 2021. Similarly, peroxide pretreatment before either of the BCAs did not seem to reduce the incidence of bulb rot as compared with the stand-alone BCA treatment in any of the trials (2020 and 2021). Additionally, our foliar microbiome study showed comparatively higher P. fluorescens retention on peroxide pretreated onion foliage; however, at the end of the growing season, P. fluorescens was drastically reduced and was virtually nonexistent (<0.002% of the total reads). Overall, the pretreatment with peroxide had a limited effect in improving the foliar colonizing ability of BCAs and consequently a limited effect in managing center rot.
Walnut Witches’-Broom Disease Threatens Butternut Restoration Efforts in Indiana
Authors: Fearer Carrie J. , Conrad Anna O.
Published: February 2023

Due to the devastating effects of butternut canker disease, efforts to protect the endangered butternut (Juglans cinerea) tree through resistance breeding have been a primary focus of forest restoration efforts. Walnut witches’-broom (WWB) disease poses a serious threat to these restoration efforts. This study sought to confirm the presence of the WWB disease phytoplasma, ‘Candidatus Phytoplasma pruni’, in butternut research plantings in Indiana using molecular methods and Sanger sequencing and to identify butternut families affected by the disease. We also sought to better understand the incidence of the WWB phytoplasma in asymptomatic trees and asymptomatic branches of symptomatic trees to better direct management decisions. Sanger sequencing confirmed the presence of the WWB phytoplasma in the butternut restoration plantings, the first confirmation in Indiana based on sequencing to our knowledge, in both symptomatic and some asymptomatic trees. In addition, the WWB phytoplasma was detected in asymptomatic branches of symptomatic trees, indicating that phytoplasma infection is not necessarily localized to symptomatic tissues in a tree. Trees with positive molecular confirmation of the WWB phytoplasma consisted of 23 different butternut families and one family of Japanese walnut (J. ailantifolia), which is considered to be one of the most susceptible species to WWB disease. Based on these findings, future studies should prioritize identifying the hybridity and pedigrees of families and their susceptibility to WWB disease to aid in butternut restoration efforts.