bluuebunny/crossref_metadata_2025 huggingface dataset:
Masked Graph Autoencoder for Self‐Supervised Transportation Mode Recognition
Authors: Zeng Ziyi , Wang Guanwen , Zhang Yifan , Guan Qingfeng , Yu Wenhao
Published: November 2024

Transportation mode recognition reveals the traveling patterns of urban residents and plays an important role in travel analysis and city planning. Research has been done to identify transportation modes using deep learning methods. However, large‐scale and far‐ranging labeled trajectory data are hard to acquire, which hinders the training and application of supervised models. In this study, we propose a self‐supervised method for trajectory transportation modes recognition. First, we construct sequence and dependency graph for trajectory points. Next, we apply mask and remask strategy to graph node features to enhance its learning ability in semantic information. Notably, in order to learn features without labeled data, we introduce graph autoencoder into the framework. This method is able to learn the sequence and dependency feature reconstruction of the travel paths. It can obtain underlying semantic information with the mask and remask strategy. We applied our model to GPS trajectory dataset from the Microsoft GeoLife Project, achieving an average accuracy of 68.26% in identifying the transportation modes among seven categories. The result indicates that the proposed method offers a solution to identifying transportation modes without abundant labeled data. This method can also help to extract space–time features at different scales from trajectory data, which could be applied to various downstream tasks.
The C2H2‐type zinc finger transcription factor ZmDi19‐7 regulates plant height and organ size by promoting cell size in maize
Authors: Dong Jinlei , Wang Zimeng , Si Weina , Xu Huan , Zhang Zhen , Cao Qiuyu , Zhang Xinyuan , Peng Hui , Mao Rongwei , Jiang Haiyang , Cheng Beijiu , Li Xiaoyu , Gu Longjiang
Published: November 2024

The drought‐induced protein 19 (Di19) gene family encodes a Cys2/His2 zinc‐finger protein implicated in responses to diverse plant stressors. To date, potential roles of these proteins as transcription factors remain largely elusive in maize. Here, we show that ZmDi19‐7 gene exerts pivotal functions in regulation of plant height and organ growth by modulating the cell size in maize. ZmDi19‐7 physically interacts with ubiquitin receptor protein ZmDAR1b, which is indispensable in ubiquitination of ZmDi19‐7 and affects its protein stability. Further genetic analysis demonstrated that ZmDAR1b act in a common pathway with ZmDi19‐7 to regulate cell size in maize. ZmDi19‐7, severing as a transcriptional factor, is significantly enriched in conserved DiBS element in the promoter region of ZmHSP22, ZmHSP18c, ZmSAUR25, ZmSAUR55, ZmSAUR7 and ZmXTH23 and orchestrates the expression of these genes involving in auxin‐mediated cell expansion and protein processing in the endoplasmic reticulum. Thus, our findings demonstrate that ZmDi19‐7 is an important newfound component of the ubiquitin‐proteasome pathway in regulation of plant height and organ size in maize. These discoveries highlight potential targets for the genetic improvement of maize in the future.
The landscape of Arabidopsis tRNA aminoacylation
Authors: Ceriotti Luis F. , Warren Jessica M. , Sanchez‐Puerta M. Virginia , Sloan Daniel B.
Published: November 2024

The function of transfer RNAs (tRNAs) depends on enzymes that cleave primary transcript ends, add a 3′ CCA tail, introduce post‐transcriptional base modifications, and charge (aminoacylate) mature tRNAs with the correct amino acid. Maintaining an available pool of the resulting aminoacylated tRNAs is essential for protein synthesis. High‐throughput sequencing techniques have recently been developed to provide a comprehensive view of aminoacylation state in a tRNA‐specific fashion. However, these methods have never been applied to plants. Here, we treated Arabidopsis thaliana RNA samples with periodate and then performed tRNA‐seq to distinguish between aminoacylated and uncharged tRNAs. This approach successfully captured every tRNA isodecoder family and detected expression of additional tRNA‐like transcripts. We found that estimated aminoacylation rates and CCA tail integrity were significantly higher on average for organellar (mitochondrial and plastid) tRNAs than for nuclear/cytosolic tRNAs. Reanalysis of previously published human cell line data showed a similar pattern. Base modifications result in nucleotide misincorporations and truncations during reverse transcription, which we quantified and used to test for relationships with aminoacylation levels. We also determined that the Arabidopsis tRNA‐like sequences (t‐elements) that are cleaved from the ends of some mitochondrial messenger RNAs have post‐transcriptionally modified bases and CCA‐tail addition. However, these t‐elements are not aminoacylated, indicating that they are only recognized by a subset of tRNA‐interacting enzymes and do not play a role in translation. Overall, this work provides a characterization of the baseline landscape of plant tRNA aminoacylation rates and demonstrates an approach for investigating environmental and genetic perturbations to plant translation machinery.
Places as refrains: A non‐constructive alternative to assemblage thinking
Authors: Merriman Peter
Published: November 2024

Over the past 20 to 30 years, relational, post‐humanist, processual, and non‐representational approaches to space and place have gained an increasing purchase within anglophone human geography, whether underpinned by academic engagements with Western philosophy, anthropology, or indigenous thinking and praxis. One approach by anglophone geographers has been to incorporate assemblage thinking into constructivist and representational accounts of the building, settling, and/or disassembling of places, but here I argue that assemblage may not be the best way to do this if we wish to foreground process and the dynamism of places. Assemblage theories place too much emphasis on the structural logics and thing‐like qualities of identifiable places, even when they aim to focus on the processual or verb‐like qualities of places. I suggest that geographers who are keen to advance processual and dynamic understandings of place can usefully (re)focus their attention on Deleuze and Guattari's writings on the ritournelle (refrain) because they articulate many of the rhythmic, repetitive, differentiated, intensive, affective, eventful, and performative qualities of placing and emplacement, while resisting any easy assimilation into constructivist and representational ‘building’ perspectives which foreground the assembly and disassembly of worlds. I outline the usefulness of Gilbert Simondon's writings on individuation and crystal growth for understanding individual‐milieu relations, before discussing Deleuze and Guattari's description of the refrain as being like a ‘glass harmonica’, which captures the reverberative, refractive, and rhythmic aspects of the concept. I then revisit a series of well‐established debates about the relationship between place and placelessness, or places and ‘non‐places’, suggesting how placelessness and non‐places can be linked to either a failed process of individuation or to uneventful expressions of a series of circulating, deterritorialising, and territorialising refrains which have differing rhythmic effects.
Bilateral diaphragmatic paralysis in a weanling donkey jack
Authors: Long Alicia E. , Underwood Claire , Wulster Kathryn , Gibson Sydney L. , Nolen‐Walston Rose
Published: November 2024

Objective

To describe the clinical presentation and diagnosis of bilateral diaphragmatic paralysis in a weanling miniature donkey jack.

Case Summary

A 5‐month‐old miniature donkey jack presented to a tertiary care facility for fever, cough, and increased respiratory rate and effort initially unresponsive to treatment with antimicrobials and anti‐inflammatories. Clinical and diagnostic evaluations found no evidence of upper respiratory obstruction or bacterial pneumonia. Serial arterial blood gas evaluations revealed hypercapnia and hypoxemia, and diagnostic imaging was consistent with bilateral diaphragmatic paralysis. The patient's nasal swab for equine influenza type A (subtype H3N8) was positive and had a mildly decreased whole blood selenium concentration. The donkey recovered after treatment with anti‐inflammatories and supportive care.

New or Unique Information Provided

This case documents the first report of diaphragmatic paralysis in a donkey, with concurrent equine influenza infection offering a possible causal factor. Bilateral diaphragmatic paralysis should be considered as a differential diagnosis for respiratory distress in donkeys, particularly when diagnostic testing or treatment trials do not support more common causes of respiratory disease in adult animals, such as infectious lower airway disease, asthma, and pulmonary fibrosis.
The establishment of reference intervals for the ClotPro thromboelastometry device in healthy dogs
Authors: Day Samantha K. , Nash Katherine J. , Midwinter Mark J. , Purcell Sarah L. , Goodwin Wendy A.
Published: November 2024

Objective

To establish reference intervals using a new point‐of‐care thromboelastometry device in dogs for the extrinsically activated test (EX‐test), intrinsically activated test (IN‐test), fibrin polymerization test (FIB‐test), ecarin test (ECA‐test), and tissue plasminogen activator test (TPA‐test) and to investigate the effects of storage time on the results.

Design

Prospective clinical study in 2022.

Setting

University teaching hospital.

Animals

Forty‐eight healthy privately or university‐owned dogs were prospectively enrolled and included on the basis of normal physical examination and normal baseline laboratory results (CBC, biochemistry profile, prothrombin time, and activated partial thromboplastin time [aPTT]).

Interventions

After a 30‐minute storage time, the EX‐test, IN‐test, FIB‐test, ECA‐test, and TPA‐test were performed on citrated blood samples. To determine the effect of storage time, 11 samples had the EX‐test, FIB‐test, and IN‐test repeated 90 and 150 minutes after sample collection.

Measurements and Main Results

Ten thromboelastometry parameters were evaluated for each test. Reference intervals were calculated using the robust method for parametric data, and the robust Box–Cox transformed or nonparametric methods were used for nonparametric data. Increasing storage time resulted in more hypocoagulable tracings. A correlation was found between the IN‐test and aPTT (r = 0.62, P < 0.0001). Other weak to moderate correlations were seen between thromboelastometry parameters and platelet count and hematocrit.

Conclusions and Clinical Importance

The development of reference intervals for the thromboelastometry device allows for the clinical use of this technology. Analyzing samples after a prolonged storage time of more than 30 minutes may result in erroneous results. Results may also be affected by an abnormal hematocrit or platelet count.
Analysis of cannabinoids in plasma from 38 cases of suspected cannabinoid intoxication in dogs
Authors: Loewen Jennifer M. , Munn‐Patterson Meara L. , McEwen Katelyn E. , Vuong Stephanie , Alcorn Jane , Chicoine Alan L.
Published: November 2024

Objective

To quantify and characterize plasma cannabinoid concentrations in cases of suspected cannabis toxicity in dogs, identify potential correlations between clinical signs and plasma concentrations, and assess the specificity of cannabis toxicity diagnosis based on clinical signs alone.

Design

Observational study.

Setting

Veterinary teaching hospital.

Animals

Thirty‐eight client‐owned animals.

Interventions

Blood was collected from dogs presenting to the emergency room for suspected cannabinoid intoxication based on history or physical examination findings. Samples were analyzed using a validated liquid chromatography–tandem mass spectrometry method for the cannabinoids Δ9‐tetrahydrocannabinol (THC), cannabidiol (CBD), and their active metabolites.

Measurements and Main Results

The most common abnormality observed was ataxia (35/38 dogs), with urinary incontinence, lethargy, and hyperesthesia also commonly noted. Cannabinoids were quantifiable in 37 of 38 plasma samples (97.4%), with THC the predominant cannabinoid (range: 1.99–2748 ng/mL). Lower concentrations of CBD (up to 115.3 ng/mL) and cannabinoid metabolites were detected. Of the clinical signs recorded, only abnormal reflexes were statistically correlated with the THC concentration at the time of sampling (P = 0.01).

Conclusions

A diagnosis of suspected cannabinoid toxicity based on case history and clinical presentation was confirmed via quantifiable plasma concentrations in nearly all cases. Although the range of plasma cannabinoid concentrations was broad, the clinical signs observed were generally similar. Other than the presence of abnormal reflexes, clinical signs were not associated with plasma THC concentrations. Subsequent confirmation of cannabinoids in plasma indicates that cannabis toxicity in dogs can be diagnosed with high specificity by veterinarians based only on history and clinical abnormalities.
The use of a nursing implementation framework to enhance the uptake of an evidence‐based intervention
Authors: Karim Kesley , Trower Sommer , Segre Lisa S.
Published: November 2024

Background

Evidence‐based practices (EBPs) are instrumental in improving patient outcomes and ensuring high‐quality nursing care, yet their implementation often encounters substantial barriers. The Iowa Implementation for Sustainability Framework and the Precision Implementation Approach© offer systematic strategies for overcoming barriers and enhancing EBP implementation and sustainability in health care settings.

Aim

This project aimed to use the Iowa Implementation for Sustainability Framework and the Precision Implementation Approach© to support the use of an evidence‐based maternal depression intervention within Iowa's Title V Maternal Health Program that serves mothers of young children living in poverty.

Methods

This practice‐based implementation was accomplished in three steps: (1) hold intervention‐focused staff meetings, (2) identify barriers to using the intervention, and (3) identify and deliver implementation strategies. Collected data included barriers identified, selected implementation strategies, and evaluation of meeting attendance and impact on confidence.

Results

Four of the monthly virtual staff meetings focused on Listening Visits (LV) use. The 7 strategies comprising our approach to supporting LV use addressed three categories of identified barriers: lack of confidence, logistical issues, and not understanding intervention procedures. In the LV‐focused meetings, representation of the 14 maternal health clinics was high, although attendance by individual staff was inconsistent. Post‐meeting polls indicated that 40% to 65% of attendees felt more confident using intervention skills.

Linking evidence to action

This practical nursing‐implementation framework facilitated EBP adoption, and our well‐structured targeted strategies effectively increased staff confidence. Nursing managers and educators should consider using this framework to enhance their organizations' capacity to implement EBPs sustainably.
Navigating the COVID-19 Health Crisis: A Content Analysis of Organizational Communication Strategies on Social Media
Authors: Wang Yuhan
Published: November 2024

The COVID-19 pandemic has posed an unprecedented threat to global health and well-being, with social media emerging as a pivotal platform for organizations to disseminate outbreak-related information swiftly, thereby shaping public risk perceptions and influencing preventive behaviours. Guided by the Crisis and Emergency Risk Communication (CERC) model, this study examines COVID-19-related content posted by organizations on Sina Weibo, focusing on the communication strategies employed and their impact on public engagement. Using content analysis and Semantic Network Analysis (SNA), a dataset of 10,996 salient Weibo posts was collected and analysed. Findings reveal that word prevalence, inter-word relationships, and the use of CERC model elements varied across different crisis stages and organization types. The analysis indicates that posts predominantly emphasized case reports, responders, governmental interventions, and positive outcomes. Furthermore, in terms of public engagement, certain content dimensions—such as requests for feedback, expressions of appreciation, and provision of detailed informational resources—were particularly effective in drawing public attention.
College Students’ Perceptions of English-medium Instruction: A Survey in a Local Chinese University
Authors: Zhang Xiaoxiao , Hu Fumao
Published: November 2024

With the internationalization and globalization of recent decades, English has increasingly become a medium of instruction at universities worldwide. This survey was conducted in a local Chinese university, and focused on college students’ needs and satisfaction regarding content, instructors, and assessment. A mixed method was employed, combining quantitative data from a questionnaire and qualitative data from interviews. The quantitative data were analyzed in SPSS 26.0, and qualitative data were analyzed in NVivo 12 plus. The findings reveal that students generally have a positive attitude towards the needs, content, instructor, and assessment satisfaction in EMI programs, which increased steadily. There is no significant difference in students’ perceptions by gender and self-proficiency, and perceptions of needs, instructor, content, and assessment satisfaction are closely correlated with the overall satisfaction. The study suggests that course design tailored students’ practical needs and advanced teaching techniques are crucial for enhancing EMI courses. Feedback was limited in students’ participation and class size. Gender differences tend to diminish in EMI university settings and English proficiency should be assessed effectively. Needs and satisfaction with content, instructor, and assessment are vital in the overall satisfaction. These insights contribute valuable recommendations for the effective implementation of EMI programs and propose avenues for further research.
Perceived Usefulness as a Mediating Variable on the Relationship Between Video Quality and Audience Emotional Engagement in Social Media
Authors: Liu Tinglei , Costa Feroz De , Yasing Megat Al Imran
Published: November 2024

Facing dual challenges of inadequate dissemination and limited acceptance, this study scrutinizes why social media struggles to promote traditional culture effectively. It identifies low-quality videos on social platforms, particularly short-form content, as the main hurdle, leading to reduced impact. Investigating the relationship between short-form video quality and audience receptivity, this study categorizes quality into media richness, impact, and interactivity dimensions. Findings confirm that higher-quality videos correlate with increased emotional engagement. Employing the Technology Acceptance Theory (TAM), perceived usefulness partially mediates the link between video quality and emotional engagement. Elevating video quality not only enhances perceived usefulness but also deepens emotional resonance, ultimately amplifying cultural impact.
Chow–Witt rings and topology of flag varieties
Authors: Hudson Thomas , Matszangosz Ákos K. , Wendt Matthias
Published: November 2024

The paper computes the Witt‐sheaf cohomology rings of partial flag varieties in type A in terms of the Pontryagin classes of the subquotient bundles. The proof is based on a Leray–Hirsch‐type theorem for Witt‐sheaf cohomology for the maximal rank cases, and a detailed study of cohomology ring presentations and annihilators of characteristic classes for the general case. The computations have consequences for the topology of real flag manifolds: we show that all torsion in the integral cohomology is 2‐torsion, which was not known in full generality previously. This allows for example to compute the Poincaré polynomials of complete flag varieties for cohomology with twisted integer coefficients. The computations also allow to describe the Chow–Witt rings of flag varieties, and we sketch an enumerative application to counting flags satisfying multiple incidence conditions to given hypersurfaces.
Load‐dependence of the activation of myosin filaments in heart muscle
Authors: Wang Yanhong , Fusi Luca , Ovejero Jesus G. , Hill Cameron , Juma Samina , Cullup Flair Paradine , Ghisleni Andrea , Park‐Holohan So‐Jin , Ma Weikang , Irving Thomas , Narayanan Theyencheri , Irving Malcolm , Brunello Elisabetta
Published: November 2024

Contraction of heart muscle requires activation of both the actin and myosin filaments. The mechanism of myosin filament activation is unknown, but the leading candidate hypothesis is direct mechano‐sensing by the filaments. Here, we tested this hypothesis by activating intact trabeculae from rat heart by electrical stimulation under different loads and measuring myosin filament activation by X‐ray diffraction. Unexpectedly, we found that the distinct structural changes in the myosin filament associated with activation had different dependences on the load. In early activation, all the structural changes indicated faster activation at higher load, as expected from the mechano‐sensing hypothesis, but, at later times, the helical order of the myosin motors characteristic of the inactivated state was lost even at very low load. We conclude that mechano‐sensing does operate in heart muscle, but it is supplemented by a previously undescribed mechanism that links myosin filament activation to actin filament activation.

image

Key points

Myosin filament activation controls the strength and speed of contraction in heart muscle.

Early activation of the myosin filament is determined by the filament load.

At later times, myosin filament activation is controlled by a load independent pathway.

This load independent pathway provides new targets and assays for drug development.
Rapid Attitude Controller Design Enabled by Flight Data
Authors: Huang Yunshen , Vu Minh , He Wenbo , Zeng Shen
Published: November 2024

In this work, we present a new approach that enables rapid learning and design of the attitude controller for quadcopters. The proposed technique leverages the dynamic structure of the system to efficiently learn an accurate linear model around the hovering position from a small batch of flight data. An linear quadratic regulator-based attitude controller is designed based on the estimation accordingly. In our approach, we may not need to conduct multiple experiments to fine-tune the controller and can accomplish such a control design with a single experiment. We further develop this approach into an onboard design framework where the attitude controller can be directly learned online and recursively fine-tunes itself with the limited onboard computation resources. The practicality and efficacy of the proposed approaches are demonstrated in both simulation and a physical quadcopter platform.
Review of progress in the taxonomy of water mites from China II (Acari: Hydrachnidia)
Authors: Jin Dao-Chao , Yi Tian-Ci , Zhang Xu , Gu Xin-Yao , Ding Zhu-Hui , Li Hai-Tao , Zheng Yu-Lin , Zhang Yu-Hao , Jia Lan , Guo Jianjun
Published: November 2024

With a brief review on taxonomic studies of Chinese water mites since 2010, this paper gives a checklist of the 381 species in 53 genera, 25 subfamilies, 23 families and 7 superfamilies, recorded from China. 25 of these (6.56%) are Palaearctic-Oriental, 85 (22.31%) Palaearctic, 271 (71.13%) Oriental in their distributions, and 290 (76.12%) are known at present only from China. The information on distribution within China is given for each species. Arrenurus (Arrenurus) bilobatus Jin & Li, 1996 is replaced with Arrenurus (Arrenurus) leishanus nomen novum, and Arrenurus (Micruracarus) bipetiolatus Jin & Wiles, 1996 with Arrenurus (Micruracarus) yibinus nomen novum.
Evolutionary mechanism of Y-branches in acoustic Lichtenberg figures just below the water surface
Authors: Lei Zhaokang , Dong Xinran , Zuo Xinyi , Wang Chenghui , Wu Yaorong , Lin Shuyu , Guo Jianzhong
Published: November 2024

The acoustic Lichtenberg figure (ALF) in an ultrasonic cleaner with a frequency of 28 kHz at different power levels was observed using high-speed photography. The nonlinear response of the cavitation structure was analyzed by the entropy spectrum in the ALF images, which showed the modulation influence of the primary acoustic field, exhibiting the fluctuations of the bubble distribution with time. Typical Y-branches predict the paths by which surrounding bubbles are attracted and converge into the structure, the branches are curved due to bubble-bubble interactions, and the curvature increases as the bubbles are approaching the main chain. The average travelling speed of bubbles along the branches is about 1.1 m/s, almost independent of power level of the ultrasonic cleaner. A theoretical model consisting of free bubbles and a straight bubble chain of finite length was developed to explore the evolutionary mechanism of branching. It was found that the bubble trajectories showed a bending tendency similar to the experimentally observed Y-branches, and the stationary straight bubble chain parallel to the main chain could evolve into a curved chain and eventually become a branch of the main chain. The theoretical predictions agree well with the experimental results, verifying the evolutionary mechanism of Y-branches in ALF.
Retrospective analysis of antimicrobial susceptibility profiles of non-
diphtheriae Corynebacterium
species from a tertiary hospital and reference laboratory, 2012–2023
Authors: Khodadadi Ryan B. , El Zein Said , Rivera (O'Connor) Christina G. , Stevens Ryan W. , Schuetz Audrey N. , Abu Saleh Omar M. , Fida Madiha
Published: November 2024

A total of 1,925
Corynebacterium
isolates were tested for antimicrobial susceptibility at the Mayo Clinic Microbiology laboratory (Rochester, Minnesota) from January 2012 to March 2023, with
C. striatum
(35.6%) and
C. amycolatum
(24.4%) identified as the predominant species. Species known to potentially carry diphtheria toxin were excluded. Common sources of isolation included skin and soft tissue (56.8%), bone and/or native joint synovial fluid (14.2%), urine (13.1%), sputum (6.1%), and blood (5.9%). For penicillin, susceptibility decreased from 47.5% (58 of 122) in 2012 to 20.6% (14 of 68) in 2023. Isolates also showed a decrease in susceptibility to erythromycin from 22.4% (26 of 116) in 2012 to 13.2% (9 of 68) in 2023. Susceptibility to trimethoprim-sulfamethoxazole averaged around 50% throughout the period. Notably, linezolid and vancomycin were universally effective
in vitro
against all species. The highest susceptibility rates among tested oral agents were to linezolid and doxycycline for non-
C
.
striatum
species. Daptomycin minimal inhibitory concentrations (MICs) of >256 µg/mL were observed for one
C. amycolatum
isolate, one
C. tuberculostearicum
isolate, and for seven
C. striatum
isolates, all from patients with prior daptomycin exposure. Daptomycin MICs of 2 µg/mL (nonsusceptible) were observed in one
C. striatum
isolate recovered from a daptomycin-naïve patient and in six
C. jeikeium
isolates, from both daptomycin-exposed and non-exposed patients. Significant variation in susceptibility profiles across different
Corynebacterium
species underscores the importance of performing antimicrobial susceptibility testing to guide effective treatment. Moreover, multidrug resistance observed in
C. striatum
poses substantial therapeutic challenges especially in patients requiring prolonged or chronic antibiotic suppression.
Small but mighty: targeted antifungal liposomes of a smaller size are superior in treating cryptococcal meningitis
Authors: Pham Tuyetnhu , Zhang Peter , Ambati Suresh , Meagher Richard B. , Lin Xiaorong
Published: November 2024

Cryptococcal meningoencephalitis (CME) is deadly. CME is responsible for 19% of deaths in AIDS patients, and its global mortality is greater than 60%. The recommended CME therapy requires amphotericin B (AmB), a fungicidal drug targeting fungal ergosterol. AmB also binds to the host’s cholesterol and is highly toxic. Liposomal AmB (AmB-LLs), relative to deoxycholate-solubilized AmB, has lower toxicity and longer tissue retention, but it requires high doses for treatment and its efficacy in treating CME remains unsatisfactory. To improve the effectiveness of AmB-LLs, we previously developed DectiSomes-targeted AmB-LLs decorated with host dectins that recognize fungal polysaccharides. DectiSomes, relative to untargeted AmB-LLs, modestly improve efficacy against systemic cryptococcosis, in contrast to the drastic improvement observed in candidiasis or aspergillosis models. We speculated that limited tissue penetration of the regular-sized DectiSomes might have contributed to the modest improvement in treating systemic cryptococcosis. Here, we discovered that DectiSomes of a smaller size (~50 nm), compared with DectiSomes of the regular size (~100 nm) or untargeted AmB-LLs of either size, had a much better capability in reducing cryptococcal burden of various organs including the brain and in prolonging the survival of mice with systemic cryptococcosis. The performance of small DectiSomes was far superior to all other groups at two different doses of AmB tested. Furthermore, no kidney toxicity was observed in any of the treatment regimens tested. Taken together, our findings indicate that small DectiSomes can be a powerful antifungal delivery platform to drastically improve therapies against the deadly CME.

IMPORTANCE

Systemic cryptococcosis is fatal even with antifungal interventions. The most effective drug against this disease is amphotericin B (AmB). However, AmB is highly toxic as it binds to fungal ergosterol and also mammalian cholesterol. Liposomal AmB was introduced to the clinic in 1990s because it showed reduced toxicity and longer retention in various organs. However, the dose of AmB required for treatment using liposomal formulation is high and the outcome is far from satisfactory. In our previous work, we generated DectiSomes, dectin-decorated liposomes loaded with AmB that more effectively deliver the drug to the pathogen and enhance antifungal efficacy. However, the improvement in treating systemic cryptococcosis, compared with candidiasis and aspergillosis, is modest. Here, we generated DectiSomes that are half their regular size to improve tissue penetration. We discovered that small DectiSomes are superior in reducing fungal burden in various organs including the brain and in prolonging animal survival.
Vibrio cholerae
CsrA controls ToxR levels by increasing the stability and translation of
toxR
mRNA
Authors: Mey Alexandra R. , Midgett Charles R. , Kull F. Jon , Payne Shelley M.
Published: November 2024

Intestinal colonization and virulence factor production in response to environmental cues is mediated through several regulatory factors in
Vibrio cholerae
, including the highly conserved RNA-binding global regulatory protein CsrA. We have shown previously that CsrA increases synthesis of the virulence-associated transcription factor ToxR in response to specific amino acids (NRES) and is required for the virulence of
V. cholerae
in the infant mouse model of cholera. In this study, we mapped the 5′ untranslated region (5′ UTR) of
toxR
and showed that CsrA can bind directly to an RNA sequence encompassing the 5′ UTR, indicating that the regulation of ToxR levels by CsrA is direct. Consistent with this observation, the 5′ UTR of
toxR
contains multiple putative CsrA binding sequences (GGA motifs), and mutating these motifs disrupted the CsrA-mediated increase in ToxR. Optimal binding of CsrA to a defined RNA oligonucleotide required the bridging of two GGA motifs within a single RNA strand. To determine the mechanism of regulation by CsrA, we assayed
toxR
transcript levels, stability, and efficiency of translation. Both the amount of
toxR
mRNA in NRES and the stability of the
toxR
transcript were increased by CsrA. Using an
in vitro
translation assay, we further showed that synthesis of ToxR was greatly enhanced in the presence of purified CsrA, suggesting a direct role for CsrA in the translation of
toxR
mRNA. We propose a model in which CsrA binding to the 5′ UTR of the
toxR
transcript promotes ribosomal access while precluding interactions with RNA-degrading enzymes.

IMPORTANCE

Vibrio cholerae
is uniquely adapted to marine environments as well as the human intestinal tract. Global regulators, such as CsrA, which help translate environmental cues into an appropriate cellular response, are critical for switching between these distinct environments. Understanding the pathways involved in relaying environmental signals is essential for understanding both the environmental persistence and the intestinal pathogenesis of this devastating human pathogen. In this study, we demonstrate that CsrA directly regulates the synthesis of ToxR, a key virulence factor of
V. cholerae
. Under conditions favoring high levels of active CsrA in the cell, such as in the presence of particular amino acids, CsrA increases ToxR protein levels by binding to the
toxR
transcript and enhancing both its stability and translation. By responding to nutrient availability, CsrA is perfectly poised to activate the virulence gene regulatory cascade at the preferred site of colonization in the human host, the nutrient-rich small intestinal mucosa.
Phenotypic and genomic characterization of ST11-K1 CR-hvKP with highly homologous
bla
KPC-2
-bearing plasmids in China
Authors: Han Yu-Ling , Wang Hua , Zhu Hong-Zhe , Lv Ying-Ying , Zhao Wen , Wang Yan-Yan , Wen Jian-Xun , Hu Zhi-De , Wang Jun-Rui , Zheng Wen-Qi
Published: November 2024

Carbapenem-resistant hypervirulent
Klebsiella pneumoniae
(CR-hvKP) strains present a significant global public health threat due to their high mortality rates. This study investigated the genomic characteristics of seven ST11-K1 CR-hvKP isolates harboring highly homologous KPC-2-encoding multidrug-resistance plasmids. The strains were isolated from a Chinese tertiary hospital between 2017 and 2020. Whole-genome sequencing and bioinformatic analysis revealed various antibiotic resistance genes (ARGs) and virulence determinants. The
bla
KPC-2
-bearing plasmids that contain multiple antibiotic-resistance genes were also identified in these strains. ISfinder and Orifinder were applied to identify insertion sequences (IS) and conjugation-related factors among these
bla
KPC-2
-bearing plasmids. The
bla
KPC-2
was highly consistent in seven
bla
KPC-2
-bearing plasmids (IS
Kpn6-bla
KPC-2
-IS
Kpn27
-IS
Yps3
-IS
26
). In addition, we found a region composed of IS
IR
, Tn
5393
, and IS
26
. It was located upstream of the
bla
CTX-M-15
gene and presented in six
bla
KPC-2
-bearing plasmids, with pCR-hvKP221-KPC-P3 as an exception. Conjugation experiments demonstrated the horizontal transfer of resistance plasmids pCR-hvKP128-KPC-P1 and pCR-hvKP132-KPC-P1 across species. Notably, pLVPK-like virulence plasmids carrying virulence gene clusters pCR-hvKP173-Vir-P1, and pCR-hvKP221-Vir-P1 were also detected. A fusional plasmid pCR-hvKP221-Vir-P2, which carries virulence gene clusters and ARGs, was also identified. Five CR-hvKP strains displayed enhanced biofilm formation and high virulence
in vivo
infection models. Phylogenetic and single nucleotide polymorphism (SNP) analyses indicated a close genetic relationship among the isolates, suggesting a subclade. These findings highlight the complex genetic profiles and potential transmission mechanisms of CR-hvKP strains.

IMPORTANCE

We reported seven CR-hvKP strains all carried a highly homologous
bla
KPC-2
integrated IncFⅡ-resistant plasmid, and two strains harbored virulence plasmids. Conjugation experiments confirmed the transferability of these plasmids, indicating a potential for resistance spread. Phylogenetic analysis clarified the relationship among the CR-hvKP isolates. This study provides insights into the phenotypic and genomic characteristics of seven ST11-K1 CR-hvKP strains. The high prevalence and potential for local outbreaks emphasize the need for effective control measures.
Transcriptional profiles of
Microcystis
reveal gene expression shifts that promote bloom persistence in
in situ
mesocosms
Authors: Krausfeldt Lauren E. , Samuel Paisley S. , Smith Robert P. , Urakawa Hidetoshi , Rosen Barry H. , Colwell Rita R. , Lopez Jose V.
Published: November 2024

Harmful algal blooms caused by cyanobacteria threaten aquatic ecosystems, the economy, and human health. Previous work has tried to identify the mechanisms that allow blooms to form, focusing on the role of nutrients. However, little is known about how introduced nutrients influence gene expression
in situ
. To address this knowledge gap, we used
in situ
mesocosms initiated with water experiencing a
Microcystis
bloom. We added pulses of nutrients that are commonly associated with anthropogenic sources to the mesocosms for 72 hours and collected samples for metatranscriptomics to examine how the physiological function of
Microcystis
and bloom status changed. The addition of nitrogen (N) as urea, but not the addition of PO
4
, resulted in conspicuous bloom persistence for at least 9 days after the final introduction of nutrients. The addition of urea initially resulted in the upregulation of photosynthesis machinery, as well as phosphate, carbon, and N transport and metabolism. Once
Microcystis
presumably became N-replete, upregulation of amino acid metabolism, microcystin biosynthesis, and other processes associated with biomass generation occurred. These capacities coincided with the upregulation of toxin-antitoxin systems, CRISPR-
cas
genes, and transposases suggesting that phage defense and genome rearrangement are critical in bloom persistence. Overall, our results show the stepwise transcriptional response of a
Microcystis
bloom to the introduction of nutrients, specifically urea, as it is sustained in a natural setting. The transcriptomic shifts observed herein may serve as markers of the longevity of blooms while providing insight into why
Microcystis
blooms over other cyanobacteria.

IMPORTANCE

Harmful algal blooms represent a threat to human health and ecosystems. Understanding why blooms persist may help us develop warning indicators of bloom persistence and create novel mitigation strategies. Using mesocosm experiments initiated with water with an active bloom, we measured the stepwise transcription changes of the toxin-producing cyanobacterium
Microcystis
in response to the addition of nutrients that are important in causing blooms. We found that nitrogen (N), but not phosphorus, promoted bloom longevity. The initial introduction of N resulted in the upregulation of genes involved in photosynthesis and N import. At later times in the bloom, upregulation of genes involved in biomass generation, phage protection, genomic rearrangement, and toxin production was observed. Our results suggest that
Microcystis
first fulfills nutritional requirements before investing energy in pathways associated with growth and protection against competitors, which allowed bloom persistence more than a week after the final addition of nutrients.
High level non-carbapenemase carbapenem resistance by overlaying mutations of
mexR
,
oprD,
and
ftsI
in
Pseudomonas aeruginosa
Authors: Yang Yan , Li Xue , Sun Lang , Wang Xiu-Kun , Zhang You-Wen , Pang Jing , Li Guo-Qing , Hu Xin-Xin , Nie Tong-Ying , Yang Xin-Yi , Liu Jian-Hua , Brandis Gerrit , You Xue-Fu , Li Cong-Ran
Published: November 2024

Carbapenem-resistant
Pseudomonas aeruginosa
(CRPA) is a global threat, but the mechanism of non-carbapenemase carbapenem resistance is still unclear. In the current study, we investigated the contributions of point mutations in
mexR
,
oprD
, and
ftsI
to carbapenem resistance in
P. aeruginosa
during
in vivo
evolution studies with consecutive clinical isolates. Real-time qPCR and Electrophoretic Mobility Shift Assay demonstrated that MexR (Gln55Pro) mutation increased MexAB efflux pump genes expression by altering MexR’s binding capacity, leading to a four- to eight-fold increase in meropenem MIC in the Pae d1 Green ∆
mexR
and PAO1∆
mexR
mutants. The OprD (Trp415*) truncation affected porin structure, and the constructed mutant Pae d1 Green
oprD
Trp415* increased meropenem MIC by 16-fold (from 0.25 to 4 µg/mL). The contribution of
ftsI
mutation to meropenem resistance was confirmed by clinical linkage analysis and was estimated to cause a two-fold increase in meropenem MIC by comparing the resistant clinical isolate with the Pae d1 Green
oprD
Trp415*∆
mexR
double mutant. The study found that the oprD Trp415* allele alone accounts for the imipenem MIC in clinical isolates, while the ∆
mexR
and
ftsI
Arg504Cys alleles do not contribute to imipenem resistance. In conclusion, we identified and explored the contributions of
mexR
,
oprD,
and
ftsI
mutations to high level non-carbapenemase carbapenem resistance in
P. aeruginosa
. These findings highlight the interplay of different mutations in causing non-carbapenemase carbapenem-resistance in
P. aeruginosa
.

IMPORTANCE

The emergence of carbapenem-resistant
Pseudomonas aeruginosa
(CRPA) poses a significant global health threat, complicating treatment options for infections caused by this pathogen. Understanding the mechanisms behind non-carbapenemase carbapenem resistance is critical for developing effective therapeutic strategies. This study provides crucial insights into how specific point mutations in key genes-
mexR
,
oprD
, and
ftsI
-contribute to carbapenem resistance, particularly the MexR (Gln55Pro) mutation’s effect on efflux pump expression and the OprD (Trp415*) truncation’s impact on porin structure. The findings elucidate the complex interplay of these mutations, highlighting their roles in conferring high-level resistance, and underscore the imperative for continued research to inform therapeutic strategies against CRPA infections.
Incidence of sudden unexplained death in childhood for children aged 1–14 years in England and Wales during 2001–2020: an observational study
Authors: Garstang Joanna Jane , Tosyali Merve , Menka Marivjena , Blair Peter S
Published: November 2024

Objective

The objective is to determine the incidence of sudden unexplained death in childhood (SUDC) for children aged 1–14 years in England and Wales during 2001–2020.

Design

Observational study using official national statistics on death registrations and child population.

Setting

England and Wales.

Patients

Children dying of SUDC, aged 1–14 years, registered as International Classification of Disease version 10 codes R95–99.

Main outcome measures

Incidence of SUDC, proportion of child mortality due to SUDC.

Results

A total of 582 children aged 1–14 years died of SUDC, 450 (77.3%) deaths were in children aged 1–4 years, 55 (9.5%) in those aged 5–9 years and 77 (13.2%) in those aged 10–14 years. The number of SUDC was relatively stable with a mean of 29 cases per year (range 21–38, SD 4.2). Overall child mortality fell from 1482 deaths in 2001 to 826 in 2020. The incidence of SUDC for children aged 1–14 years ranged between 0.002 and 0.004 per 1000. The relative proportion of child mortality due to SUDC increased from 1.96% of all child deaths in 2001 to 3.03% in 2020 (p=0.103), SUDC accounted for 5.8% of deaths of children aged 1–4 years by 2020. At all ages, SUDC was more common in male children than female children.

Conclusion

The incidence of SUDC has remained static despite overall child mortality almost halving in the last two decades. SUDC is now more widely recognised due to improved investigation, but there has been limited research into SUDC; potential causes and associated risk factors remain unknown. As the relative proportion of child deaths due to SUDC increases, child health professionals must be aware of SUDC to support bereaved families.
Successful oral phytonadione (vitamin K) challenge following an infusion-related reaction to intravenous phytonadione
Authors: Farley T Michael , Leary Daniel J , Poelker Faith R
Published: November 2024

A woman in her early 60s presented to the emergency room with worsening pain 10 days after an injury to her right abdomen. CT revealed a large subcutaneous haematoma and contained small bowel perforation. She was tachycardic and anaemic and her international normalized ratio (INR) was 2.6 on warfarin for atrial fibrillation. General surgery was consulted and percutaneous drainage of the perforation was recommended, requiring an INR of 1.5 or less. Intravenous (IV) phytonadione was administered to accelerate the lowering of INR; however, the patient developed a severe infusion-related reaction. She recovered once IV phytonadione was stopped and oral diphenhydramine was administered. However, there was still a need for warfarin reversal therapy. A 1.25 mg dose of oral phytonadione was trialled 2.5 hours later and well tolerated. An additional rechallenge of 5 mg by mouth was given without reaction (<8 hours after the initial reaction). Her INR was 1.5 the next morning.
Refractive changes in children in the Chicago area during the COVID-19 pandemic: a retrospective observational study
Authors: Kim Eugene , Stec Magdalena , Shaikh Noreen , Huang Jonathan , Ralay Ranaivo Hantamalala , Mets-Halgrimson Rebecca
Published: November 2024

Background

Remote learning during the COVID-19 pandemic caused behavioural changes such as increased screen time and decreased outdoor time. This study aimed to investigate myopia progression in children during the COVID-19 pandemic.

Methods

This was a retrospective observational study performed among 2064 patients ages 2–17 with cycloplegic refractions in the months of January 2019–March 2021 at a tertiary children’s hospital. Exclusion criteria were a medical history of relevant connective tissue diseases, myopia control treatment, pseudophakia and aphakia.

Results

The overall cohort (n=2064) had a mean spherical equivalent (SE) of 0.12±3.70 D in 2019, −0.07±3.95 D in 2020 and −0.49±3.85 D in 2021. The change in mean SE (0.42 D) from 2020 to 2021 was 2.2 times greater than the change (0.19 D) from 2019 to 2020 at baseline. In the cohort of return patients, there was a significant difference in myopic shift between years (F-ratio=14.4, p<0.00001), and a significant change from 2020 to 2021 (p=0.00008) but not from 2019 to 2020. When observing the prevalence of myopia grouped by age, 8-year-old and 17-year-old patients had the greatest increase compared with baseline. When grouped by refractive error, low myopia children (−0.5 D to −3.00 D) displayed the greatest change in mean SE 2020–2021.

Conclusions

There was a substantial increase in myopia progression for children in the Chicagoland area after the period of COVID-19 changes. The behavioural changes of home confinement and online learning during the pandemic may explain these findings.