bluuebunny/crossref_metadata_2025_split huggingface dataset:
A genome catalogue of mercury‐methylating bacteria and archaea from sediments of a boreal river facing human disturbances
Authors: Lawruk‐Desjardins Charlène , Storck Veronika , Ponton Dominic E. , Amyot Marc , Walsh David A. 
Published: June 2024

AbstractMethyl mercury, a toxic compound, is produced by anaerobic microbes and magnifies in aquatic food webs, affecting the health of animals and humans. The exploration of mercury methylators based on genomes is still limited, especially in the context of river ecosystems. To address this knowledge gap, we developed a genome catalogue of potential mercury‐methylating microorganisms. This was based on the presence of hgcAB from the sediments of a river affected by two run‐of‐river hydroelectric dams, logging activities and a wildfire. Through the use of genome‐resolved metagenomics, we discovered a unique and diverse group of mercury methylators. These were dominated by members of the metabolically versatile Bacteroidota and were particularly rich in microbes that ferment butyrate. By comparing the diversity and abundance of mercury methylators between sites subjected to different disturbances, we found that ongoing disturbances, such as the input of organic matter related to logging activities, were particularly conducive to the establishment of a mercury‐methylating niche. Finally, to gain a deeper understanding of the environmental factors that shape the diversity of mercury methylators, we compared the mercury‐methylating genome catalogue with the broader microbial community. The results suggest that mercury methylators respond to environmental conditions in a manner similar to the overall microbial community. Therefore, it is crucial to interpret the diversity and abundance of mercury methylators within their specific ecological context.
Fungi rather than bacteria drive early mass loss from fungal necromass regardless of particle size
Authors: Pérez‐Pazos Eduardo , Beidler Katilyn V. , Narayanan Achala , Beatty Briana H. , Maillard François , Bancos Alexandra , Heckman Katherine A. , Kennedy Peter G. 
Published: June 2024

AbstractMicrobial necromass is increasingly recognized as an important fast‐cycling component of the long‐term carbon present in soils. To better understand how fungi and bacteria individually contribute to the decomposition of fungal necromass, three particle sizes (>500, 250–500, and <250 μm) of Hyaloscypha bicolor necromass were incubated in laboratory microcosms inoculated with individual strains of two fungi and two bacteria. Decomposition was assessed after 15 and 28 days via necromass loss, microbial respiration, and changes in necromass pH, water content, and chemistry. To examine how fungal–bacterial interactions impact microbial growth on necromass, single and paired cultures of bacteria and fungi were grown in microplates containing necromass‐infused media. Microbial growth was measured after 5 days through quantitative PCR. Regardless of particle size, necromass colonized by fungi had higher mass loss and respiration than both bacteria and uninoculated controls. Fungal colonization increased necromass pH, water content, and altered chemistry, while necromass colonized by bacteria remained mostly unaltered. Bacteria grew significantly more when co‐cultured with a fungus, while fungal growth was not significantly affected by bacteria. Collectively, our results suggest that fungi act as key early decomposers of fungal necromass and that bacteria may require the presence of fungi to actively participate in necromass decomposition.
Comparative analysis of enzymatic profiles and biofilm formation in clinical and environmental Candida kefyr isolates
Authors: Nouraei Hasti , Zare Samira , Nemati Maryam , Amirzadeh Neda , Motamedi Marjan , Shabanzadeh Shafigheh , Zomorodian Kamiar , Pakshir Keyvan 
Published: June 2024

AbstractThe global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence of non‐albicans Candida species, which are often less susceptible to antifungal treatment. Candida kefyr, in particular, has been increasingly associated with infections. This study aimed to investigate the profiles of enzymatic activity and biofilm formation in both clinical and non‐clinical isolates of C. kefyr. A total of 66 C. kefyr isolates were analysed. The activities of proteinase and phospholipase were assessed using bovine serum albumin and egg yolk agar, respectively. Haemolysin, caseinolytic and esterase activities were evaluated using specific methods. Biofilm formation was investigated using crystal violet staining. The findings indicated that biofilm and proteinase activity were detected in 81.8% and 93.9% of all the isolates, respectively. Haemolysin activity was observed with the highest occurrence (95.5%) among normal microbiota isolates. Esterase activity was predominantly identified in dairy samples and was absent in hospital samples. Caseinase production was found with the highest occurrence (18.2%) in normal microbiota and hospital samples. Phospholipase activity was limited, found in only 3% of all the isolates. These findings reveal variations in enzyme activity between clinical and non‐clinical C. kefyr isolates. This sheds light on their pathogenic potential and has implications for therapeutic strategies.
Comparative resistomics analysis of multidrug‐resistant Chryseobacteria
Authors: Pham Dung Ngoc , Li Mengyan 
Published: June 2024

AbstractChryseobacteria consists of important human pathogens that can cause a myriad of nosocomial infections. We isolated four multidrug‐resistant Chryseobacterium bacteria from activated sludge collected at domestic wastewater treatment facilities in the New York Metropolitan area. Their genomes were sequenced with Nanopore technology and used for a comprehensive resistomics comparison with 211 Chryseobacterium genomes available in the public databases. A majority of Chryseobacteria harbor 3 or more antibiotic resistance genes (ARGs) with the potential to confer resistance to at least two types of commonly prescribed antimicrobials. The most abundant ARGs, including β‐lactam class A (blaCGA‐1 and blaCIA) and class B (blaCGB‐1 and blaIND) and aminoglycoside (ranA and ranB), are considered potentially intrinsic in Chryseobacteria. Notably, we reported a new resistance cluster consisting of a chloramphenicol acetyltransferase gene catB11, a tetracycline resistance gene tetX, and two mobile genetic elements (MGEs), IS91 family transposase and XerD recombinase. Both catB11 and tetX are statistically enriched in clinical isolates as compared to those with environmental origins. In addition, two other ARGs encoding aminoglycoside adenylyltransferase (aadS) and the small multidrug resistance pump (abeS), respectively, are found co‐located with MGEs encoding recombinases (e.g., RecA and XerD) or transposases, suggesting their high transmissibility among Chryseobacteria and across the Bacteroidota phylum, particularly those with high pathogenicity. High resistance to different classes of β‐lactam, as well as other commonly used antimicrobials (i.e., kanamycin, gentamicin, and chloramphenicol), was confirmed and assessed using our isolates to determine their minimum inhibitory concentrations. Collectively, though the majority of ARGs in Chryseobacteria are intrinsic, the discovery of a new resistance cluster and the co‐existence of several ARGs and MGEs corroborate interspecies and intergenera transfer, which may accelerate their dissemination in clinical environments and complicate efforts to combat bacterial infections.
Kinetics and pathways of sub‐lithic microbial community (hypolithon) development
Authors: Bosch Jason , Lebre Pedro H. , Marais Eugene , Maggs‐Kölling Gillian , Cowan Don A. 
Published: June 2024

AbstractType I hypolithons are microbial communities dominated by Cyanobacteria. They adhere to the underside of semi‐translucent rocks in desert pavements, providing them with a refuge from the harsh abiotic stresses found on the desert soil surface. Despite their crucial role in soil nutrient cycling, our understanding of their growth rates and community development pathways remains limited. This study aimed to quantify the dynamics of hypolithon formation in the pavements of the Namib Desert. We established replicate arrays of sterile rock tiles with varying light transmission in two areas of the Namib Desert, each with different annual precipitation regimes. These were sampled annually over 7 years, and the samples were analysed using eDNA extraction and 16S rRNA gene amplicon sequencing. Our findings revealed that in the zone with higher precipitation, hypolithon formation became evident in semi‐translucent rocks 3 years after the arrays were set up. This coincided with a Cyanobacterial ‘bloom’ in the adherent microbial community in the third year. In contrast, no visible hypolithon formation was observed at the array set up in the hyper‐arid zone. This study provides the first quantitative evidence of the kinetics of hypolithon development in hot desert environments, suggesting that development rates are strongly influenced by precipitation regimes.
Seed or soil: Tracing back the plant mycobiota primary sources
Authors: Laurent‐Webb Liam , Maurice Kenji , Perez‐Lamarque Benoît , Bourceret Amélia , Ducousso Marc , Selosse Marc‐André 
Published: June 2024

AbstractPlants host diverse communities of fungi (the mycobiota), playing crucial roles in their development. The assembly processes of the mycobiota, however, remain poorly understood, in particular, whether it is transmitted by parents through the seeds (vertical transmission) or recruited in the environment (horizontal transmission). Here we attempt to quantify the relative contributions of horizontal and vertical transmission in the mycobiota assembly of a desert shrub, Haloxylon salicornicum, by comparing the mycobiota of in situ bulk soil and seeds to that of (i) in situ adult individuals and (ii) in vitro‐germinated seedlings in soil collected in situ. We show that the mycobiota are partially vertically transmitted through the seeds to seedlings, whereas bulk soil has a limited contribution to the seedling's mycobiota. In adults, root and bulk soil mycobiota tend to resemble each other, suggesting a compositional turnover in plant mycobiota during plant development due to horizontal transmission. Thus, the mycobiota are transmitted both horizontally and vertically depending on the plant tissue and developmental stage. Understanding the respective contribution of these transmission pathways to the plant mycobiota is fundamental to deciphering potential coevolutionary processes between plants and fungi. Our findings particularly emphasize the importance of vertical transmission in desert ecosystems.
Evidence of a putative CO2 delivery system to the chromatophore in the photosynthetic amoeba Paulinella
Authors: Gabr Arwa , Stephens Timothy G. , Reinfelder John R. , Liau Pinky , Calatrava Victoria , Grossman Arthur R. , Bhattacharya Debashish 
Published: June 2024

AbstractThe photosynthetic amoeba, Paulinella provides a recent (ca. 120 Mya) example of primary plastid endosymbiosis. Given the extensive data demonstrating host lineage‐driven endosymbiont integration, we analysed nuclear genome and transcriptome data to investigate mechanisms that may have evolved in Paulinella micropora KR01 (hereinafter, KR01) to maintain photosynthetic function in the novel organelle, the chromatophore. The chromatophore is of α‐cyanobacterial provenance and has undergone massive gene loss due to Muller's ratchet, but still retains genes that encode the ancestral α‐carboxysome and the shell carbonic anhydrase, two critical components of the biophysical CO2 concentrating mechanism (CCM) in cyanobacteria. We identified KR01 nuclear genes potentially involved in the CCM that arose via duplication and divergence and are upregulated in response to high light and downregulated under elevated CO2. We speculate that these genes may comprise a novel CO2 delivery system (i.e., a biochemical CCM) to promote the turnover of the RuBisCO carboxylation reaction and counteract photorespiration. We posit that KR01 has an inefficient photorespiratory system that cannot fully recycle the C2 product of RuBisCO oxygenation back to the Calvin‐Benson cycle. Nonetheless, both these systems appear to be sufficient to allow Paulinella to persist in environments dominated by faster‐growing phototrophs.
Prevalence and correlates of daily‐level reasons not to drink among young adults who use alcohol
Authors: Arterberry Brooke J. , Peterson Sarah J. , Schepis Ty S. , Patrick Megan E. 
Published: June 2024

AbstractBackgroundThis study examined reasons not to drink in young adults in relation to demographics, alcohol use patterns, timing (weekend vs. weekday), and typical drinking motives.MethodsYoung adults who reported past 30‐day alcohol use and at least one nondrinking day (n = 614; mean age = 21.5 years ±0.53) completed a survey of alcohol‐related measures (e.g., typical drinking motives) and up to 14 daily surveys that included 12 reasons not to drink assessed on nondrinking days. Multilevel logistic regressions were estimated for each reason not to drink and related covariates.ResultsThe most common reasons not to drink on a given day were “wasn't interested in drinking” (83.4% of nondrinking days) and “didn't want to get drunk” (81.8% of nondrinking days), with over 96% of participants endorsing each of these at least once. On days (11.6%; by 29.5% of participants) when another drug was used instead of alcohol, 81.8% used cannabis. Sex, race/ethnicity, weekend (vs. weekday), and drinking motives were differentially linked to reasons not to drink. Reporting high‐intensity drinking (i.e., ≥10 drinking on a day) versus binge (5–9 drinks on a day) in the past 2 weeks was linked to “had a hangover recently” (odds ratio = 2.85) as a reason not to drink.ConclusionsFindings suggest that reasons not to drink reflect personal decisions and highlight ways to acknowledge situational barriers (e.g., saving money for food and essentials) that can be emphasized in brief interventions. Furthermore, reasons not to drink and alcohol motives may work in tandem within the motivational model to impact alcohol use behaviors.
Quitting intentions and behaviours among young Australian e‐cigarette users
Authors: Jongenelis Michelle I. , Gill Melissa , Lawrence Nicole , Wakefield Claire E. 
Published: June 2024

AbstractBackground and aimsWith the prevalence of e‐cigarette use among Australian youth increasing significantly in recent years, greater attention is being paid to encouraging and supporting cessation. However, research to inform such efforts is lacking. The present study sought to (i) measure desire to quit e‐cigarette use and actual quitting attempts among young Australians and (ii) explore correlates of quitting‐related cognitions and behaviours.Design, setting and participantsThis was a cross‐sectional on‐line survey conducted in Australia. The participants were 14−25‐year‐old e‐cigarette users (n = 602; 53% women).MeasurementsDesire to quit vaping and attempts to quit vaping were the primary dependent variables. The independent variables included several individual (e.g. harm perceptions, perceived appeal of vapes), social (descriptive norms) and environmental (e.g. ease of e‐cigarette access) factors.FindingsA majority of respondents (61%) expressed a desire to quit vaping, and just over half (55%) had made a quit attempt. Finding vapes easy to access was associated with both a lack of desire [odds ratio (OR) = 0.71] and attempts to quit (OR = 0.77), while self‐reported addiction to vaping (OR = 1.42 and OR = 3.11) and perceiving vaping to be associated with mental health risks (OR = 1.30 and OR = 1.40) were positively correlated with these variables. Perceiving that vaping is common among people of one’s age (OR = 0.82) and finding vapes appealing (OR = 0.55) were associated with a lack of desire to quit, while perceiving vaping to have physical health risks was positively associated with quitting desire (OR = 1.58). School‐based education on vaping was associated with reporting an attempt/s to quit (OR = 0.47).ConclusionsThis survey of young Australian e‐cigarette users suggests a high level of desire to quit using e‐cigarettes and attempts to quit. Increasing knowledge regarding the physical and mental health risks associated with e‐cigarette use may assist with promoting quitting‐related intentions. Changing social norms, reducing the accessibility of e‐cigarettes and reducing the appeal of the products also constitute potential means of increasing the desire to quit.
Shape analysis of the carpal joint in healthy and septic arthritis in newborn calves
Authors: Koçak Sedef , Özaydin İsa , Gündemir Ozan 
Published: June 2024

AbstractSeptic arthritis is common in newborn calves due to poor birth and housing hygiene. This study investigated the pathological deformities caused by arthritis in the carpal bones of calves using geometric morphometry. The changes in the carpal joint bones of newborn calves with septic arthritis were examined through shape analysis. The study included 20 healthy Simmental calves and 30 Simmental calves with septic arthritis. Dorso‐palmar x‐ray images of the carpal joint were taken, and geometric morphometry was performed on these images using 25 landmarks. The first principal components (PC1) represented 26.92% of the total variation, while PC2 represented 13.84%. One of the most significant shape changes with increasing PC1 occurred in the os carpi intermedium. The study found that it was statistically possible to discriminate between radiometric carpal joint images of Simmental calves in the control and arthritis groups using geometric morphometry. In newborn calves with septic arthritis, the trochlea radi was located more proximally. There was an enlargement of the os carpi intermedium and a tendency towards the os carpi ulnare in female calves with septic arthritis. These results indicate significant bone deformation due to septic arthritis. Geometric morphometric methods can be clinically useful, as demonstrated in this study. Researchers can statistically explore these shape analyses, opening new avenues for research in this field. This method not only enhances our understanding of morphological changes but also provides a framework for clinical investigations and discoveries in related areas.
Informational lobbying and commercial diplomacy
Authors: Thrall Calvin 
Published: June 2024

AbstractWhat determines thecontentof bilateral diplomacy? I argue that the foreign policy issues prioritized by specific embassies are influenced by their diplomats' sources of information. For evidence, I study the proliferation of American Chambers of Commerce (AmChams)—private interest groups composed of US firms that are operating in specific host states—over the 20th and early 21st centuries. AmChams became key sources of information for US embassies, particularly on issues of relevance to the private sector (such as tax, trade, and investment regulations). Using novel text data from approximately 1500 oral history interviews with former diplomats, and leveraging the institutional structure of diplomatic rotation, I show that diplomats who were exposed to active AmCham branches paid significantly greater attention to commercial issues. These results identify a new avenue through which interest groups can influence foreign policy, help explain the proliferation of probusiness international agreements over the past several decades, and contribute to the growing literature on diplomacy in the international political economy.
Race, legislative speech, and symbolic representation in Congress
Authors: Vishwanath Arjun 
Published: June 2024

AbstractWe know little about the extent to which racial minorities are symbolically represented by members of Congress. This stands in contrast to a wealth of research analyzing the extent to which minorities are substantively and descriptively represented. This article provides the most comprehensive analysis of symbolic representation to date. Using data on legislators’ speech from 105,875 newsletters and 620,838 floor speeches, I find that White legislators of both parties are more likely to symbolically represent Blacks, Hispanics, and Asians if those groups are more populous in their constituency. However, these effects only hold cross‐sectionally; using a difference‐in‐differences setup from redistricting shocks, I find that there is little within‐legislator variation in speech patterns as their constituencies change. Lastly, I show that, unlike on the symbolic dimension, legislators’ substantive representation is not influenced by group size. I conclude that White legislators are symbolically responsive to their constituents’ identities in their speech patterns.
Voted in, standing out: Public response to immigrants' political accession
Authors: Zonszein Stephanie , Grossman Guy 
Published: June 2024

AbstractHow do dominant‐group natives react to immigrants' political integration? We argue that ethnic minority immigrants winning political office makes natives feel threatened, triggering animosity. We test this dynamic across the 2010–2019 UK general elections, using hate crime police records, public opinion data, and text data from over 500,000 regional and local newspaper articles. While past work has not established a causal relationship between minorities' political power gains and dominant‐group animosity, we identify natives' hostile reactions with a regression discontinuity design that leverages close election results between immigrant‐origin ethnic minority and dominant‐group candidates. We find that minority victories increase hate crimes by 67%, exclusionary attitudes by 66%, and negative media coverage of immigrant groups by 110%. Consistent with power threat and social identity theories, these findings demonstrate a strong and widespread negative reaction—encompassing a violence‐prone fringe and the mass public—against ethnic minority immigrants' integration into majority settings.
Uncertain times: The causal effects of coups on national income
Authors: Grier Kevin , Grier Robin , Moncrieff Henry J. 
Published: June 2024

AbstractWe use doubly robust difference‐in‐differences models to estimate the causal effect of successful coups on national incomes. We find that real per capita gross domestic product (GDP) decreases by 10%–12% 5 years after a coup and the effect has not begun to diminish at that point. When we investigate the economic and political mechanisms behind this outcome, we find that our result is mostly driven by a fall in investment and in the rule of law, along with an increase in repression. Given the size of the effect, preventing coups can be seen as a significant development issue, and though the international community has taken steps to discourage coups, further consideration of anticoup policies seems well‐warranted.