bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between sleep and interoception
Authors: Bynum Louisa G. , Brindle Ryan C.
Published: September 2024

The present study aimed to characterise the relationship between sleep and interoception in two independent studies. Theoretical grounds for such a relationship include a weak relationship between subjectively‐ and objectively‐measured sleep, the covariance of sleep with pain, as well as the mass regulation of a number of visceral biological systems. In addition, such a relationship is often reflected in our language (i.e., ‘feeling’ tired). In both studies (Study 1: N = 118, 73% female, mean age 20.98 years; Study 2: N = 830, 49% female, mean age 38.04 years) sleep over the last month was self‐reported. Confidence in interoceptive accuracy, which is the precision with which a person can monitor visceral signals, was measured using the Interoceptive Accuracy Scale, while interoceptive attention, which is the dispositional tendency to attend to bodily signals, was measured using the Body Perception Questionnaire. Study 1 revealed a relationship between long sleep latency and low confidence in interoceptive accuracy (β = −0.222, p = 0.021) and poor sleep quality and less interoceptive attention (β = −0.226, p = 0.016). Study 2 replicated these results as well as made clear a more general pattern whereby poor sleep—characterised by short duration, poor quality, less efficiency, long latency, and more frequent nighttime awakenings—related to an interoceptive phenotype of less confidence in interoceptive accuracy and more interoceptive attention (all β ≥ 0.047, p ≤ 0.17). In conclusion, results from these two independent studies provide robust cross‐sectional evidence for associations between various dimensions of poor sleep and greater interoceptive attention, but less confidence in interoceptive accuracy.
Will Americans Vote for an Atheist?
Authors: CAMPBELL DAVID E. , LAYMAN GEOFFREY C. , MARSH WAYDE Z. C.
Published: September 2024

Conventional wisdom holds and previous research confirms that for a political candidate, atheism is anathema. But the United States is becoming a more secular nation. Does secularization mean that atheists are acceptable to some Americans, specifically Democrats and voters with low religiosity? Can concerns about atheists be assuaged by appealing to the superordinate identity of “patriotic American”? Drawing on four survey experiments, we find that Democrats are more supportive of an atheist, Republicans less—producing a null effect overall. Furthermore, voters’ reactions to an atheist are not driven by the office, but are shaped by both their partisanship and religiosity. Voters’ negative attitudes are partially assuaged by framing an atheist as a patriotic war hero. As the secular population grows in the United States, it seems likely that atheists will emerge as candidates for elected office. Our data suggest that, contrary to conventional wisdom, atheist candidates are potentially electable.
Weak link or strong foundation? Vulnerability of fine root networks and stems to xylem embolism
Authors: Harrison Day Beatrice L. , Brodersen Craig R. , Brodribb Timothy J.
Published: September 2024

Resolving the position of roots in the whole‐plant hierarchy of drought‐induced xylem embolism resistance is fundamental for predicting when species become isolated from soil water resources. Published research generally suggests that roots are the most vulnerable organ of the plant vascular system, although estimates vary significantly. However, our knowledge of root embolism excludes the fine roots (< 2 mm diameter) that form the bulk of total absorptive surface area of the root network for water and nutrient uptake.

We measured fine root and stem xylem vulnerability in 10 vascular plant species from the major land plant clades (five angiosperms, three conifers, a fern and lycophyte), using standardised in situ methods (Optical Methods and MicroCT).

Mean fine root embolism resistance across the network matched or exceeded stems in all study species. In six of these species (one fern, one lycophyte, three conifers and one angiosperm), fine roots were significantly more embolism resistant than stems. No clear relationship was found between root xylem conduit diameter and vulnerability.

These results provide insight into the resistance of the plant hydraulic pathway at the site of water and nutrient uptake, and challenge the long‐standing assumption that fine roots are more vulnerable than stems.
Interactions between kisspeptin and bone: Cellular mechanisms, clinical evidence, and future potential
Authors: Mills Edouard G. , Abbara Ali , Dhillo Waljit S. , Comninos Alexander N.
Published: September 2024

The neuropeptide kisspeptin and its cognate receptor have been extensively studied in reproductive physiology, with diverse and well‐established functions, including as an upstream regulator of pubertal onset, reproductive hormone secretion, and sexual behavior. Besides classical reproduction, both kisspeptin and its receptor are extensively expressed in bone‐resorbing osteoclasts and bone‐forming osteoblasts, which putatively permits direct bone effects. Accordingly, this sets the scene for recent compelling findings derived from in vitro experiments through to in vivo and clinical studies revealing prominent regulatory interactions for kisspeptin signaling in bone metabolism, as well as certain oncological aspects of bone metabolism. Herein, we comprehensively examine the experimental evidence obtained to date supporting the interaction between kisspeptin and bone. A comprehensive understanding of this emerging facet of kisspeptin biology is fundamental to exploiting the future therapeutic potential of kisspeptin‐based medicines as a novel strategy for treating bone‐related disorders.
Spiritual capital and spiritual entrepreneurship: The new spiritualities and the processes of subjectivation
Authors: Navarrete‐Saavedra Rodrigo , Gallardo‐Vergara René
Published: September 2024

This paper critically examines the constructs of spiritual capital and spiritual entrepreneurship/entrepreneur. These concepts have recently become widespread in the social sciences and the psychology of the New Age, or the new spiritualities, and they are also increasingly present in business literature, organizational management, and personal improvement in managerial terms. From a critical social psychology position, the paper will consider the usefulness of these concepts in revealing how the field of spirituality currently seems to be a favoured space of governmentality and subjectivation for neoliberalism.
Climate‐related disasters and transparency: Records and the United States Federal Emergency Management Agency
Authors: Sterett Susan M.
Published: September 2024

Objective

Many governments aim for transparency for accountability. Transparency and its processes contribute to governing climate. The transparency agenda focuses on sharing records to inform the public. In the United States, accessible records also add to decision‐making processes since records are useful to contest decisions. Few people put together the two kinds of transparency, sharing and challenging. Analyzing both is critical as calls for acting on climate‐related disasters grow.

Method

In the United States, the Federal Emergency Management Agency (FEMA) shares records. The Freedom of Information Act (FOIA) is one route to access FEMA's records. To assess transparency, I coded FEMA's 2019 FOIA log for requester and record requested. Years of damaging, notable disasters preceded 2019, but 2019 precedes pandemic disruptions.

Result

Requesters can make requests likely to be useful instrumentally, concerning assistance and insurance. Journalists and scholars request records useful to conceptualizing governing disaster to include both individual political officials and aggregate bureaucratic policy. Instrumental requests dominate, as they do for other agencies.

Conclusion

This article answers the call in recent studies of transparency, policy, and of disaster governance to track how policies embed power. Assessing record requests contributes to understanding the accountability in freedom of information.
Monolithic Chinese political culture?: A cross‐regional exploration
Authors: Harmel Robert , Li Zhaoqing , Shen Chen , Yeh Yao‐Yuan
Published: September 2024

Objective

This article explores whether authoritarian China has a monolithic political culture, or rather a set of somewhat different political cultures across a number of regions.

Method

On the basis of several criteria we deem particularly important for identifying regions within which development, communication, and socialization of political attitudes are likely to be internally common but distinguishable from those of other regions, we divide China into six such regions. We then employ a combination of eight attitudinal measures from The China Survey of 2008 which are directly relevant to discerning political culture.

Results

We find that there are indeed substantively different cultures across regions, some of which are more consistent with elite preferences than others.

Conclusion

From our initial foray into possible explanation, we conclude that politico‐historical legacy—sometimes in interaction with certain aspects of geographic, demographic, and economic characteristics—may go furthest in explaining the cross‐region cultural differences.
On certainty, Left Wittgensteinianism and conceptual change
Authors: Mollema W. J. T.
Published: September 2024

What are the limits of Left Wittgensteinianism's point‐ and need‐based account of conceptual change? Based upon Wittgenstein's account of certainty and the riverbed analogy for conceptual change in On Certainty, the question is raised whether Queloz and Cueni's redevelopment of Left Wittgensteinianism can account for the multiplicitous forms of change these concepts are subject to. I argue that Left Wittgensteinianism can only partially do so, because it overemphasises the role of criticism‐driven conceptual change, due to its focus on the reason‐based contingency of the practices of a local ‘we’. In response, it is argued that Left Wittgensteinianism should be fortified with (i) gradual changes to concepts' sociocultural constraints that concept‐users are unaware of and (ii) evolutionary and environmental changes to the biological determinants of natural constraints of conceptual cores. In the end, there are conceptual practices like holding for certain that are generally, and fully contingent, but simultaneously inevitable not only for ‘us’ but also for many other delimitations of ‘we’. Subsequently, the compatibility of this Wittgensteinian account of conceptual change with pragmatic genealogy is discussed. It is concluded that thinking about conceptual changes to practices cannot be about the possibility of criticism alone nor succeed without the inclusion thereof.
Polynomial Chaos Expansion-Based Uncertainty Model for Fast Assessment of Gas Turbine Aero-Engines Thrust Regulation: A Sparse Regression Approach
Authors: Li Shijia , Wei Zhiyuan , Zhang Shuguang , Cen Zhaohui , Tsoutsanis Elias
Published: September 2024

Manufacturing tolerance uncertainties in gas turbine aero-engines are unavoidable, which adversely influence the thrust control performance of newly produced aero-engines. However, classic sample-based uncertainty quantification approaches are usually computationally intensive. In this paper, to consider the uncertainties in the thrust control design phase in advance, a polynomial chaos expansion-based uncertainty model (PCEUM) using a sparse regression method is proposed to get the accurate probability distribution of thrust regulation performance and other concerned engine variables at a decreased computational burden. In PCEUM, interested engine parameters are initially expressed as linear combinations of several orthogonal polynomials, whose weighting coefficients are solved by a sparse-regression-based method, i.e., orthogonal matching pursuit (OMP). Meanwhile, two classic sample-based uncertainty quantification approaches, (i.e., Monte Carlo simulations (MCS), Latin hypercube sampling (LHS)) and least angle regression (LARS) are set as benchmarks. Numerical simulations on a verified large turbofan engine model at the takeoff state on a desktop computer show that PCEUM costs only 47.06 s at 200 samples to obtain converged probability distributions for interested engine parameters whose errors of mean and standard deviation are within 0.01% and 1%, respectively, compared to MCS at 100,000 samples. Meanwhile, compared to the latter three methods, PCEUM saves 94.5%, 81.2%, and 13.1% of the simulation time, accordingly. Hence, both the accuracy and speed of the proposed model are guaranteed for the uncertainty assessment of thrust regulation, which provides a promising solution for both conventional and future aero-propulsion system.
A Low Mach Preconditioned Harmonic Balance Solver for Cavity Flutter Computations
Authors: Sivel Pierre , Frey Christian , Kersken Hans-Peter , Kügeler Edmund
Published: September 2024

Labyrinth seal flutter is a critical phenomenon in turbomachinery, as it can lead to severe structural vibrations and potential component damage. Accurate prediction and mitigation of flutter are paramount to ensuring the reliability and performance of modern turbomachinery systems. This paper explores the numerical computation of a labyrinth seal flutter test case using a low Mach preconditioned harmonic balance (HB) solver and investigates how this approach can improve the accuracy and response time of flutter computations. HB solvers have gained prominence in turbomachinery computations for their ability to efficiently capture unsteady flow phenomena and significantly reduce computational time compared to time-domain analyses. In labyrinth seals, however, the flow is often characterized by low Mach numbers, and preconditioning for these conditions has been shown to significantly improve convergence and accuracy. The goal of this paper is to demonstrate how to implement low Mach preconditioning in a HB solver in the frequency domain. We employ iterative preconditioning to alleviate the stiffness associated with density-based solvers under low Mach conditions and analyze the effect of the preconditioning parameters on the convergence rate. Furthermore, we address inaccuracies linked to the classical Roe solver in low Mach scenarios by adapting it to the low Mach preconditioned governing equations. Through the combined utilization of iterative preconditioning and a preconditioned Roe solver, this study aims to improve convergence rates and the overall quality of flutter predictions. We demonstrate the method with an academic labyrinth seal test case originally presented by Corral et al. (“Higher Order Conceptual Model for Labyrinth Seal Flutter,” ASME J. Turbomach., 143(7), p. 071006). While previous investigations have primarily relied on linearized frequency domain solvers and reduce-order models, in this research a preconditioned HB solver is applied to this test case.
Novel Soft Gripper With Adjustable Performance Based on Blade Flexures
Authors: Arredondo-Soto Mauricio , Cuan-Urquizo Enrique , Gómez-Espinosa Alfonso , Roman-Flores Armando , Ahmad Rafiq
Published: September 2024

The design of soft grippers is challenging as the target objects to be handled involve a wide variety of sizes, shapes, and softness. Most grippers reported present drawbacks, e.g., complex control strategies for stiffness and force variation, inadequate adaptability to target shape variability, and complicated adaptation to manipulators, which in turn limit their implementation in applications such as harvesting. This paper presents a novel overlay soft gripper based on an assembling mechanism and passive soft structures, enabling the modification of grip size, orientation, and gripping force. This gripper can be assembled over a commercial robot-gripper taking the closing motion of this as the input to perform its closing motion. Input and output parameters are related by means of the displacement transmission mechanism which converts the closing motion of the robot-gripper into the closing motion of the overlay soft gripper. The gripping force can be modified through the change of stiffness, via adjustment of effective length using contact elements, of internal blade flexures. The displacement transmission mechanism works in two modes: as rigid-body mechanism without the contact elements and as rigid-body/flexible mechanism with the contact elements. The relationships between input and output parameters are obtained analytically for the case of rigid-body mechanism, and through finite element analysis simulations for the case of rigid-body/flexible mechanism. Relationships between input and output parameters are approximated with polynomial surfaces. Finally, physical prototypes are manufactured and assembled on their respective robot-grippers to qualitatively demonstrate their performance.
An Efficient Integral Approach for Kinematic Reliability Sensitivity Analysis of Industrial Robots
Authors: Shen Shuoshuo , Zhang Dequan , Liu Weipeng , Liu Jie , Han Xu
Published: September 2024

Assessment of the reliability and reliability sensitivity of positioning accuracy for industrial robots subject to aleatoric and epistemic uncertainties registers a challenging task. This study proposes a new optimized moment-based method for kinematic reliability analysis and its sensitivity analysis, which incorporates the sparse grid (SPGR) technique and the saddlepoint approximation (SPA) method. To start with, the positioning accuracy reliability and its sensitivity models of industrial robots are established via computational optimization techniques and kinematic criteria. The kinematic accuracy reliability and its sensitivity are then calculated. Specifically, the sparse grid technique is adopted to approach the positioning error statistical moments and moment sensitivities. On this basis, positioning accuracy reliability bounds and reliability sensitivity bounds are obtained by the saddlepoint approximation method and optimization techniques. Finally, two practical examples are implemented to demonstrate the proficiency of the currently proposed method against Monte Carlo simulation (MCS) results. The results show that the currently proposed method exhibits superior computational accuracy and efficiency in kinematic reliability and its sensitivity analyses for industrial robots.
Effect of NH3 flow rate to titanium nitride as etch hard mask in thermal atomic layer deposition
Authors: Kang Ju Eun , Hong Sang Jeen
Published: September 2024

Managing the hardness, density, and residual stress of the titanium nitride (TiN) hard mask has become increasingly significant for achieving excellent selectivity in the high aspect ratio etching process. This research investigates the enhancement of hardness, density, residual stress, and etch selectivity of a TiN film during the atomic layer deposition process using varying NH3 flow rates. Additionally, the study establishes a correlation between the improvement of hard mask properties and NH3 flow rates, taking into account the film composition, crystallinity, surface roughness, interface layers, and film thickness. The effects of NH3 could be summarized into three types. High N–N and Ti–N bonds, along with increased film hardness, are achieved by elevating the NH3 flow rate. Furthermore, this adjustment promotes the growth of crystal planes with higher lattice constants and modifies the interface layer thickness between Si and TiN, directly impacting residual stress. The TiN film exhibits increased roughness and decreased uniformity. In addition, at NH3 50 SCCM, hardness, density, and residual stress improved by 81.8%, 110%, and 87.5%, respectively. The selectivity saw a significant increase of 77.7%. This study provides an analysis of the relationship between the NH3 flow rate and TiN thin film properties, which is essential for improving TiN hard mask properties in flow type reactors.
Catalyzing Inclusive Excellence: Transformative Practices of Auburn University’s School of Kinesiology
Authors: Miller Matthew W. , Wilburn Christopher M. , Baweja Harsimran S. , Rudisill Mary E. , Russell Jared A.
Published: September 2024

The School of Kinesiology (KINE) at Auburn University (AU) has demonstrated exemplary commitment to diversity, equity, and inclusion, earning the 2024 American Kinesiology Association’s Inclusive Excellence Award. This article describes the strategic planning and actions taken by AU KINE over more than a decade to promote inclusive excellence by enhancing diversity and fostering inclusion. The article discusses how AU KINE overcame challenges, such as misconceptions about diversity initiatives, and how the unit continues to evolve, including developing an inclusive Doctor of Physical Therapy program. Throughout the process, AU KINE has aligned its diversity and inclusion mission and goals with the broader institution. The authors aim to demystify the process of creating a more diverse and inclusive kinesiology department and offer insights for other programs seeking to enhance their diversity and inclusion efforts. AU KINE’s success demonstrates the transformative power of strategic, sustained initiatives to promote inclusive excellence in kinesiology.
Decreased dust particles amplify the cloud cooling effect by regulating cloud ice formation over the Tibetan Plateau
Authors: Chen Jingchuan , Xu Jianzhong , Wu Zhijun , Meng Xiangxinyue , Yu Yan , Ginoux Paul , DeMott Paul J. , Xu Rui , Zhai Lixiang , Yan Yafei , Zhao Chuanfeng , Li Shao-Meng , Zhu Tong , Hu Min
Published: September 2024

Ice-nucleating particles (INPs) can initiate cloud ice formation, influencing cloud radiative effects (CRE) and climate. However, the knowledge of INP sources, concentrations, and their impact on CRE over the Tibetan Plateau (TP)—a highly climate-sensitive region—remains largely hypothetical. Here, we integrated data from multisource satellite observations and snowpack samples collected from five glaciers to demonstrate that dust particles constitute primary INP sources over the TP. The springtime dust influxes lead to seasonally elevated ice concentrations in mixed-phase clouds. Furthermore, the decadal reduction in dustiness from 2007 to 2019 results in decreased springtime dust INPs, thereby amplifying the cooling effect of clouds over the TP, with a 1.98 ± 0.39–watt per square meter reduction in surface net CRE corresponding to a 0.01 decrease in dust optical depth. Our findings elucidate previously unidentified pathways of climate feedback from an atmospheric INP perspective, especially highlighting the crucial role of dust in aerosol-cloud interactions.
Positronium image of the human brain in vivo
Authors: Moskal Paweł , Baran Jakub , Bass Steven , Choiński Jarosław , Chug Neha , Curceanu Catalina , Czerwiński Eryk , Dadgar Meysam , Das Manish , Dulski Kamil , Eliyan Kavya V. , Fronczewska Katarzyna , Gajos Aleksander , Kacprzak Krzysztof , Kajetanowicz Marcin , Kaplanoglu Tevfik , Kapłon Łukasz , Klimaszewski Konrad , Kobylecka Małgorzata , Korcyl Grzegorz , Kozik Tomasz , Krzemień Wojciech , Kubat Karol , Kumar Deepak , Kunikowska Jolanta , Mączewska Joanna , Migdał Wojciech , Moskal Gabriel , Mryka Wiktor , Niedźwiecki Szymon , Parzych Szymon , del Rio Elena P. , Raczyński Lech , Sharma Sushil , Shivani Shivani , Shopa Roman Y. , Silarski Michał , Skurzok Magdalena , Tayefi Faranak , Ardebili Keyvan T. , Tanty Pooja , Wiślicki Wojciech , Królicki Leszek , Stępień Ewa Ł.
Published: September 2024

Positronium is abundantly produced within the molecular voids of a patient’s body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.
Diversity of
Clostridioides difficile
PCR ribotypes isolated from freshwater sediments depends on the isolation method
Authors: Rupnik Maja , Fuks Alen , Janezic Sandra
Published: September 2024

Clostridioides difficile
is an intestinal pathogen of humans and animals. In community-associated infections, the environment is suggested to play a significant role in overall transmission routes. Although the prevalence of
C. difficile
in freshwater and soil has been widely studied, little is known about its presence in sediments. In this study, we tested 15 sediment samples collected from various freshwater sources.
C. difficile
was isolated from all sampled sites, yielding a total of 171 strains grouped into 26 ribotypes, with 001/072 and 014/020 being the most prevalent. Genome sequencing of 37 isolates from 17 PCR ribotypes confirmed the presence of highly related strains in the geographically distant and unlinked water samples. Eight divergent PCR ribotypes from clades C-II and C-III were found in six samples. In each sample, the unbound fraction (supernatant after sediment wash) and bound fraction (sonicated sediment sample) were subjected to enrichment. Sonication was only slightly better than washing in terms of sample positivity (14 positive samples with sonication and 11 with washing). However, sonication substantially increased the diversity of the PCR ribotypes obtained (23 in sonicated samples vs nine in washed samples). In conclusion, sediments are a rich source for investigating the diversity of environmental
C. difficile,
including isolates from divergent lineages. Selection of the isolation method can significantly impact the diversity of captured PCR ribotypes.

IMPORTANCE

Clostridioides difficile
, a pathogenic bacterium that can cause intestinal infections in humans and animals, thrives in the gut but also disperses widely through spores found in the environment. Clinical and environmental strains often overlap with common PCR ribotypes, which are consistently isolated worldwide. Environmental studies have mostly focused on water and soil, but sediments have been very poorly studied. In this study, we investigated the presence of
C. difficile
in various freshwater sediments and evaluated the effectiveness of two different isolation approaches on positivity rates and strain diversity.
C. difficile
was found to be highly prevalent in sediments, with an isolation rate of 100%. Sonication proved to be more effective than simple washing for capturing a greater diversity of PCR ribotypes. Overall, this study underscores the widespread presence of
C. difficile
in freshwater sediments and emphasizes the importance of continued surveillance and monitoring to understand its ecology and transmission dynamics.
Salmonella
Typhimurium infection inhibits macrophage IFNβ signaling in a TLR4-dependent manner
Authors: Shuster Michael , Lyu Zhihui , Augenstreich Jacques , Mathur Shrestha , Ganesh Akshaya , Ling Jiqiang , Briken Volker
Published: September 2024

Type I Interferons (IFNs) generally have a protective role during viral infections, but their function during bacterial infections is dependent on the bacterial species.
Legionella pneumophila
,
Shigella sonnei
and
Mycobacterium tuberculosis
can inhibit type I IFN signaling. Here we examined the role of type I IFN, specifically IFNβ, in the context of
Salmonella enterica
serovar Typhimurium (STm) macrophage infections and the capacity of STm to inhibit type I IFN signaling. We demonstrate that IFNβ has no effect on the intracellular growth of STm in infected bone marrow derived macrophages (BMDMs) derived from C57BL/6 mice. STm infection inhibits IFNβ signaling but not IFNγ signaling in a murine macrophage cell line. We show that this inhibition is independent of the type III and type VI secretion systems expressed by STm and is also independent of bacterial phagocytosis. The inhibition is Toll-like receptor 4 (TLR4)-dependent as the TLR4 ligand, lipopolysaccharide (LPS), alone is sufficient to inhibit IFNβ-mediated signaling. Cells downregulated their surface levels of IFNα/β receptor 1 (IFNAR1) in response to LPS, which may be mediating our observed inhibition. Lastly, we examined this inhibition in the context of TLR4-deficient BMDMs as well as TLR4 RNA interference and we observed a loss of inhibition with LPS stimulation as well as STm infection. In summary, we show that macrophages exposed to STm have reduced IFNβ signaling via crosstalk with TLR4 signaling, which may be mediated by reduced host cell surface IFNAR1, and that IFNβ signaling does not affect cell-autonomous host defense against STm.
Graduate teaching assistants’ beliefs and practices regarding mentoring in the context of an online introductory biology CURE: an exploratory study
Authors: Santillan Karen A. , Rediske Andrea M. , Olimpo Jeffrey T.
Published: September 2024

Course-based undergraduate research experiences (CUREs) have been identified as a promising approach to engage large numbers of students in discovery-based investigations in the biological sciences. As the prevalence of CUREs continues to increase nationwide, the role of graduate teaching assistants (TAs) in facilitating these courses has simultaneously grown. In addition to serving as instructors of CUREs, previous research suggests that educators—including TAs—must also adopt additional roles, including that of a mentor. However, few studies have explicitly examined CURE TAs’ beliefs and practices regarding mentorship. To address this need, we conducted an exploratory, concurrent mixed methods study to better understand TAs’ self-reported mentoring skills levels and their experiences acting as potential mentors in the context of an online introductory biology SEA-PHAGES CURE. Results indicate that TAs (
N
= 12) believed themselves most skilled in areas related to listening and communication, building rapport with students, and encouraging independence with respect to student research projects. Analysis of open-ended survey data further demonstrated that the overwhelming majority of TAs (
n
= 10) considered themselves to be mentors, citing a diversity of rationales reflective of both psychosocial and instrumental forms of mentoring support. Collectively, these outcomes contribute to a growing body of literature on the nature and level of involvement of TAs within CURE learning environments, particularly with respect to their posited role as mentors.
Fibroblast stromal support model for predicting human papillomavirus-associated cancer drug responses
Authors: James Claire D. , Lewis Rachel L. , Fakunmoju Alexis L. , Witt Austin J. , Youssef Aya H. , Wang Xu , Rais Nabiha M. , Prabhakar Apurva T. , Machado J. Mathew , Otoa Raymonde , Bristol Molly L.
Published: September 2024

Currently, there are no specific antiviral therapeutic approaches targeting Human papillomaviruses (HPVs), which cause around 5% of all human cancers. Specific antiviral reagents are particularly needed for HPV-related oropharyngeal cancers (HPV
+
OPCs) whose incidence is increasing and for which there are no early diagnostic tools available. We and others have demonstrated that the estrogen receptor alpha (ERα) is overexpressed in HPV
+
OPCs, compared to HPV-negative cancers in this region, and that these elevated levels are associated with an improved disease outcome. Utilizing this HPV
+
-specific overexpression profile, we previously demonstrated that estrogen attenuates the growth and cell viability of HPV
+
keratinocytes and HPV
+
cancer cells
in vitro
. Expansion of this work
in vivo
failed to replicate this sensitization. The role of stromal support from the tumor microenvironment (TME) has previously been tied to both the HPV lifecycle and
in vivo
therapeutic responses. Our investigations revealed that
in vitro
co-culture with fibroblasts attenuated HPV
+
-specific estrogen growth responses. Continuing to monopolize on the HPV
+
-specific overexpression of ERα, our co-culture models then assessed the suitability of the selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen, and showed growth attenuation in a variety of our models to one or both of these drugs
in vitro
. Utilization of these SERMs
in vivo
closely resembled the sensitization predicted by our co-culture models. Therefore, the
in vitro
fibroblast co-culture model better predicts
in vivo
responses. We propose that utilization of our co-culture
in vitro
model can accelerate cancer therapeutic drug discovery.

IMPORTANCE

Human papillomavirus-related cancers (HPV
+
cancers) remain a significant public health concern, and specific clinical approaches are desperately needed. In translating drug response data from
in vitro
to
in vivo
, the fibroblasts of the adjacent stromal support network play a key role. Our study presents the utilization of a fibroblast 2D co-culture system to better predict translational drug assessments for HPV
+
cancers. We also suggest that this co-culture system should be considered for other translational approaches. Predicting even a portion of treatment paradigms that may fail
in vivo
with a co-culture model will yield significant time, effort, resource, and cost efficiencies.
Feeling hormonal? Insights into bacterial auxin sensing and its physiological effects
Authors: van der Meij Anne
Published: September 2024

Plant–microbe communication involves a rich language of chemical signals. Among these signals are plant hormones such as auxins, which are primarily recognized for their roles in plant development. However, they also function in modulating plant–microbe interactions. Interestingly, many bacteria are capable of producing auxins too. Yet, the mechanisms by which auxins affect bacteria and the regulatory processes controlling their production are largely unknown. Rico-Jiménez and colleagues present new insights into the effects of the auxin indole-3-acetic acid on the physiology of the rhizobacterium
Serratia plymuthica
(M. Rico-Jiménez, Z. Udaondo, T. Krell, and M. A. Matilla, mSystems 9:e00165-24, 2024,
https://doi.org/10.1128/msystems.00165-24
). Their work provides a deeper mechanistic understanding of bacterial transcriptional responses to plant hormones and the impact on bacterial fitness in the context of the rhizosphere environment.
In vitro
evaluation of the automated hematology analyzer XN-31 for rapid diagnosis of equine piroplasmosis
Authors: Ochi Akihiro , Toya Yuji , Sengoku Mikako , Tsuchiya Seiichiro , Kishi Daiki , Ueno Takanori
Published: September 2024

Equine piroplasmosis (EP) is a protozoal disease affecting equids, caused by
Theileria equi
and
Babesia caballi
. EP is conventionally diagnosed using microscopic, molecular, and/or serological methods, which are time-consuming. Consequently, there is a need for faster testing methods. In this study, we evaluated the application of the Sysmex XN-31 automated hematology analyzer, originally a rapid test for detecting malaria in humans, for the diagnosis of EP. The cultured parasites were measured using the XN-31 that had been customized for horse blood samples (XN-31m). The following parameters were evaluated: limit of detection (LoD), limit of quantification (LoQ), linearity, carryover, precision, and correlation with microscopic examination. The XN-31m detected infected red blood cells (RBCs) in approximately 1 minute. The LoD and LoQ for
B. caballi
were 4.54 infected RBCs/μL and 14.10 infected RBCs/μL, while those for
T. equi
were 5.80 infected RBCs/μL and 11.44 infected RBCs/μL, respectively. Linearity showed excellent correlation (
R
2
> 0.99), and carryover never exceeded 0.5%. The coefficient of variation was under 5%. The correlation between the results obtained using XN-31m and microscopic examination was high (
R
2
> 0.98). In conclusion, the XN-31 analyzer detected
B. caballi
and
T. equi
parasites in approximately 1 minute with high sensitivity. The results indicate the potential of the XN-31 analyzer as a fast and user-friendly diagnostic method for EP.

IMPORTANCE

In this study, we demonstrated that the automated hematology analyzer, XN-31, can detect red blood cells infected with
Babesia caballi
and
Theileria equi
in about 1 minute. We evaluated the diagnostic performance of the XN-31 analyzer for equine piroplasmosis, providing evidence of its potential as a diagnostic tool for this disease.
Selection for amoxicillin-, doxycycline-, and enrofloxacin-resistant
Escherichia coli
at concentrations lower than the ECOFF in broiler-derived cecal fermentations
Authors: Swinkels Aram F. , Fischer Egil A. J. , Korving Lisa , Kusters Nina E. , Wagenaar Jaap A. , Zomer Aldert L.
Published: September 2024

Antimicrobial resistance (AMR) is an emerging worldwide problem and a health threat for humans and animals. Antimicrobial usage in human and animal medicine or in agriculture results in selection for AMR. The selective concentration of antimicrobial compounds can be lower than the minimum inhibitory concentration and differs between environments, which can be a reason for bacterial resistance. Therefore, knowledge of the minimal selective concentration (MSC), under natural conditions, is essential to understand the selective window of bacteria when exposed to residual antimicrobials. In this study, we estimated the MSCs of three antimicrobials, amoxicillin, doxycycline, and enrofloxacin in a complex microbial community by conducting fermentation assays with cecal material derived from broilers. We examined the phenotypic resistance of
Escherichia coli
, resistome, and microbiome after 6 and 30 hours of fermenting in the presence of the antimicrobials of interest. The concentrations were estimated to be 10–100 times lower than the epidemiological cut-off values in
E. coli
for the respective antimicrobials as determined by EUCAST, resulting in an MSC between 0.08 and 0.8 mg/L for amoxicillin, 0.4 and 4 mg/L for doxycycline, and 0.0125 and 0.125 mg/L for enrofloxacin. Additionally, resistome analysis provided an MSC for doxycycline between 0.4 and 4 mg/L, but amoxicillin and enrofloxacin exposure did not induce a significant difference. Our findings indicate at which concentrations there is still selection for antimicrobial-resistant bacteria. This knowledge can be used to manage the risk of the emergence of antimicrobial-resistant bacteria.

IMPORTANCE

Antimicrobial resistance possibly affects human and animal health, as well as economic prosperity in the future. The rise of antimicrobial-resistant bacteria is a consequence of using antimicrobial compounds in humans and animals selecting for antimicrobial-resistant bacteria. Concentrations reached during treatment are known to be selective for resistant bacteria. However, at which concentrations residues are still selective is important, especially for antimicrobial compounds that remain in the environment at low concentrations. The data in this paper might inform decisions regarding guidelines and regulations for the use of specific antimicrobials. In this study, we are providing these minimal selective concentrations for amoxicillin, doxycycline, and enrofloxacin in complex environments.
Microbial interactions impact stress tolerance in a model oral community
Authors: Lewin Gina R. , Evans Emma R. , Whiteley Marvin
Published: September 2024

Understanding the molecular mechanisms governing microbial interactions is crucial for unraveling the complexities of microbial communities and their ecological impacts. Here, we employed a two-species model system comprising the oral bacteria
Aggregatibacter actinomycetemcomitans
and
Streptococcus gordonii
to investigate how synergistic and antagonistic interactions between microbes impact their resilience to environmental change and invasion by other microbes. We used an
in vitro
colony biofilm model and focused on two
S
.
gordonii
-produced extracellular molecules, L-lactate and H
2
O
2
, which are known to impact fitness of this dual-species community. While the ability of
A. actinomycetemcomitans
to cross-feed on
S. gordonii
-produced L-lactate enhanced its fitness during co-culture, this function showed little impact on the ability of co-cultures to resist environmental change. In fact, the ability of
A. actinomycetemcomitans
to catabolize L-lactate may be detrimental in the presence of tetracycline, highlighting the complexity of interactions under antimicrobial stress. Furthermore, H
2
O
2
, known for its antimicrobial properties, had negative impacts on both species in our model system. However, H
2
O
2
production by
S. gordonii
enhanced
A. actinomycetemcomitans
tolerance to tetracycline, suggesting a protective role under antibiotic pressure. Finally,
S. gordonii
significantly inhibited the bacterium
Serratia marcescens
from invading
in vitro
biofilms, but this inhibition was lost during co-culture with
A. actinomycetemcomitans
and in a murine abscess model, where
S. gordonii
actually promoted
S. marcescens
invasion. These data indicate that microbial interactions can impact fitness of a bacterial community upon exposure to stresses, but these impacts are highly environment dependent.

IMPORTANCE

Microbial interactions are critical modulators of the emergence of microbial communities and their functions. However, how these interactions impact the fitness of microbes in established communities upon exposure to environmental stresses is poorly understood. Here, we utilized a two-species community consisting of
Aggregatibacter actinomycetemcomitans
and
Streptococcus gordonii
to examine the impact of synergistic and antagonistic interactions on microbial resilience to environmental fluctuations and susceptibility to microbial invasion. We focused on the
S. gordonii
-produced extracellular molecules, L-lactate and H
2
O
2
, which have been shown to mediate interactions between these two microbes. We discovered that seemingly beneficial functions, such as
A. actinomycetemcomitans
cross-feeding on
S. gordonii
-produced L-Lactate, can paradoxically exacerbate vulnerabilities, such as susceptibility to antibiotics. Moreover, our data highlight the context-dependent nature of microbial interactions, emphasizing that a seemingly potent antimicrobial, such as H
2
O
2
, can have both synergistic and antagonistic effects on a microbial community dependent on the environment.
Molecular characterization of a novel putative pathogen,
Streptococcus nakanoensis
sp. nov., isolated from sputum culture
Authors: Wajima Takeaki , Sugawara Takashi , Tanaka Emi , Uchiya Kei-ichi
Published: September 2024

Reports of novel species of α-hemolytic
Streptococcus
have increased recently. However, limited information exists regarding the pathogenicity of these species, with the exception of
Streptococcus pneumoniae
and
Streptococcus pseudopneumoniae
. In this study, a quinolone-resistant α-
Streptococcus
strain, MTG105, was isolated from the sputum of a patient with pneumonia. This strain was first identified as
S. pneumoniae
at the hospital laboratory; however, it exhibited unique genetic features upon further analysis. Digital DNA-DNA hybridization and average nucleotide identity based on BLAST values from whole-genome sequencing revealed MTG105 to be a novel species closely related to
S. pseudopneumoniae
. Although MTG105 carried two copies of the pneumolysin gene, similar to
S. pseudopneumoniae
, this isolate exhibited susceptibility to optochin under both aerobic and 5% CO
2
conditions. Notably, no biochemical features could be used to definitively identify this species. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that of
S. pneumoniae
and
S. pseudopneumoniae
, possibly suggesting its potential as a pathogenic α-
Streptococcus
. The natural transformation abilities of
Streptococcus
species facilitate their exchange of genes within the same genus, resulting in the existence of species with increasingly more diverse genome structures. Therefore, the identification of this species highlights the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance. This isolate was proposed as a novel species, designated
Streptococcus nakanoensis
sp. nov. The type strain was MTG 105
T
(= JCM 35953
T
= CCUG 76894
T
).

IMPORTANCE

The genus
Streptococcus
encompasses a wide range of bacteria with more than 60 species. Recently, there has been a notable increase in reports of novel species of α-
Streptococcus
based on genomic analysis data. However, limited information exists regarding the pathogenicity of these species. In this study, a quinolone-resistant α-hemolytic
Streptococcus
strain, MTG105, was isolated from a patient with pneumonia. Genetic analysis revealed that this species was a novel species closely related to
S. pseudopneumoniae
. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that caused by
S. pneumoniae
and
S. pseudopneumoniae
, strongly suggesting its potential as a pathogenic α-
Streptococcus
. The natural transformation abilities of
Streptococcus
species facilitate gene exchange within the same genus, leading to the emergence of species with increasingly diverse genome structures. Therefore, the identification of this species underscores the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance.