Global arthropod beta-diversity is spatially and temporally structured by latitude.

Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework. Sampling includes 129 sampling sites whereby malaise traps are deployed to monitor temporal changes in arthropod communities. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assess between site differences in community diversity using beta-diversity and the partitioned components of species replacement and richness difference. Global total beta-diversity (dissimilarity) increases with decreasing latitude, greater spatial distance and greater temporal distance. Species replacement and richness difference patterns vary across biogeographic regions. Our findings support long-standing, general expectations of global biodiversity patterns. However, we also show that the underlying processes driving patterns may be regionally linked.

Diurnal transcriptional variation is reduced in a nitrogen-fixing diatom endosymbiont.

Many organisms have formed symbiotic relationships with nitrogen (N)-fixing bacteria to overcome N limitation. Diatoms in the family Rhopalodiaceae host unicellular, N-fixing cyanobacterial endosymbionts called spheroid bodies (SBs). Although this relationship is relatively young, SBs share many key features with older endosymbionts, including coordinated cell division and genome reduction. Unlike free-living relatives that fix N exclusively at night, SBs fix N largely during the day; however, how SB metabolism is regulated and coordinated with the host is not yet understood. We compared four SB genomes, including those from two new host species (Rhopalodia gibba and Epithemia adnata), to build a genome-wide phylogeny which provides a better understanding of SB evolutionary origins. Contrary to models of endosymbiotic genome reduction, the SB chromosome is unusually stable for an endosymbiont genome, likely due to the early loss of all mobile elements. Transcriptomic data for the R. gibba SB and host organelles addressed whether and how the allocation of transcriptional resources depends on light and nitrogen availability. Whereas allocation to the SB was high under all conditions, relative expression of chloroplast photosynthesis genes increased in the absence of nitrate, but this pattern was suppressed by nitrate addition. SB expression of catabolism genes was generally greater during daytime rather than at night, although the magnitude of diurnal changes in expression was modest compared to free-living cyanobacteria. We conclude that SB daytime catabolism likely supports N-fixation by linking the process to host photosynthetic carbon fixation.

Duplicate Gene Expression and Possible Mechanisms of Paralog Retention During Bacterial Genome Expansion.

Gene duplication contributes to the evolution of expression and the origin of new genes, but the relative importance of different patterns of duplicate gene expression and mechanisms of retention remains debated and particularly poorly understood in bacteria. Here, we investigated gene expression patterns for two lab strains of the cyanobacterium Acaryochloris marina with expanding genomes that contain about 10-fold more gene duplicates compared with most bacteria. Strikingly, we observed a generally stoichiometric pattern of greater combined duplicate transcript dosage with increased gene copy number, in contrast to the prevalence of expression reduction reported for many eukaryotes. We conclude that increased transcript dosage is likely an important mechanism of initial duplicate retention in these bacteria and may persist over long periods of evolutionary time. However, we also observed that paralog expression can diverge rapidly, including possible functional partitioning, for which different copies were respectively more highly expressed in at least one condition. Divergence may be promoted by the physical separation of most Acaryochloris duplicates on different genetic elements. In addition, expression pattern for ancestrally shared duplicates could differ between strains, emphasizing that duplicate expression fate need not be deterministic. We further observed evidence for context-dependent transcript dosage, where the aggregate expression of duplicates was either greater or lower than their single-copy homolog depending on physiological state. Finally, we illustrate how these different expression patterns of duplicated genes impact Acaryochloris biology for the innovation of a novel light-harvesting apparatus and for the regulation of recA paralogs in response to environmental change.

A programmatic update on COVID-19 vaccination in rural communities in the United States.

When public health experts think of rural barriers to vaccines, they often initially focus on access, which makes sense with a new vaccine during a pandemic. This commentary highlights that there can be more complexity to vaccine uptake in rural communities. What follows are some examples of CDC's efforts to better understand rural health and learnings to inform ongoing vaccination efforts in rural communities.

Shoulder terminal sensory articular nerve radiofrequency ablation for non-surgical refractory shoulder pain due to rotator cuff pathology and osteoarthritis: A technical note.

BACKGROUND: Given the high prevalence of chronic shoulder pain and encouraging early results of terminal sensory articular branch (TSAB) radiofrequency ablation to treat shoulder pain, research is warranted to refine the procedural technique based on updated neuroanatomical knowledge with the goal of further improving patient outcomes. OBJECTIVE: We describe an updated radiofrequency ablation protocol that accounts for varied locations of the TSABs of suprascapular, axillary, subscapular and lateral pectoral nerves within individual patients. DESIGN: Technical note. METHODS: Cadaveric studies delineating the sensory innervation of the shoulder joint were reviewed, and a more comprehensive radiofrequency ablation (RFA) protocol is proposed relative to historical descriptions. CONCLUSIONS: Based on neuroanatomical dissections of the shoulder joint, the proposed RFA protocol will provide a safe means of more complete sensory denervation and potentially improve clinical outcomes compared to historical descriptions, which must be confirmed in prospective studies.

Scaffold-Oriented Asymmetric Catalysis: Conformational Modulation of Transition State Multivalency during a Catalyst-Controlled Assembly of a Pharmaceutically Relevant Atropisomer.

A new class of superbasic, bifunctional peptidyl guanidine catalysts is presented, which enables the organocatalytic, atroposelective synthesis of axially chiral quinazolinediones. Computational modeling unveiled the conformational modulation of the catalyst by a novel phenyl urea N-cap, that preorganizes the structure into the active, folded state. A previously unanticipated noncovalent interaction involving a difluoroacetamide acting as a hybrid mono- or bidentate hydrogen bond donor emerged as a decisive control element inducing atroposelectivity. These discoveries spurred from a scaffold-oriented project inspired from a fascinating investigational BTK inhibitor featuring two stable chiral axes and relies on a mechanistic framework that was foreign to the extant lexicon of asymmetric catalysis.

Enantioselective Sulfonimidamide Acylation via a Cinchona Alkaloid-Catalyzed Desymmetrization: Scope, Data Science, and Mechanistic Investigation.

Methods to access chiral sulfur(VI) pharmacophores are of interest in medicinal and synthetic chemistry. We report the desymmetrization of unprotected sulfonimidamides via asymmetric acylation with a cinchona-phosphinate catalyst. The desired products are formed in excellent yield and enantioselectivity with no observed bis-acylation. A data-science-driven approach to substrate scope evaluation was coupled to high throughput experimentation (HTE) to facilitate statistical modeling in order to inform mechanistic studies. Reaction kinetics, catalyst structural studies, and density functional theory (DFT) transition state analysis elucidated the turnover-limiting step to be the collapse of the tetrahedral intermediate and provided key insights into the catalyst-substrate structure-activity relationships responsible for the origin of the enantioselectivity. This study offers a reliable method for accessing enantioenriched sulfonimidamides to propel their application as pharmacophores and serves as an example of the mechanistic insight that can be gleaned from integrating data science and traditional physical organic techniques.

ß-amino acids reduce ternary complex stability and alter the translation elongation mechanism.

Templated synthesis of proteins containing non-natural amino acids (nnAAs) promises to vastly expand the chemical space available to biological therapeutics and materials. Existing technologies limit the identity and number of nnAAs than can be incorporated into a given protein. Addressing these bottlenecks requires deeper understanding of the mechanism of messenger RNA (mRNA) templated protein synthesis and how this mechanism is perturbed by nnAAs. Here we examine the impact of both monomer backbone and side chain on formation and ribosome-utilization of the central protein synthesis substate: the ternary complex of native, aminoacylated transfer RNA (aa-tRNA), thermally unstable elongation factor (EF-Tu), and GTP. By performing ensemble and single-molecule fluorescence resonance energy transfer (FRET) measurements, we reveal the dramatic effect of monomer backbone on ternary complex formation and protein synthesis. Both the (R) and (S)-ß2 isomers of Phe disrupt ternary complex formation to levels below in vitro detection limits, while (R)- and (S)-ß3-Phe reduce ternary complex stability by approximately one order of magnitude. Consistent with these findings, (R)- and (S)-ß2-Phe-charged tRNAs were not utilized by the ribosome, while (R)- and (S)-ß3-Phe stereoisomers were utilized inefficiently. The reduced affinities of both species for EF-Tu ostensibly bypassed the proofreading stage of mRNA decoding. (R)-ß3-Phe but not (S)-ß3-Phe also exhibited order of magnitude defects in the rate of substrate translocation after mRNA decoding, in line with defects in peptide bond formation that have been observed for D-α-Phe. We conclude from these findings that non-natural amino acids can negatively impact the translation mechanism on multiple fronts and that the bottlenecks for improvement must include consideration of the efficiency and stability of ternary complex formation.

Draft genome of co-cultured Melainabacteria sp. 17Bon1m.

We report the 7.6 Mb draft genome sequence of Melainabacteria sp. strain 17Bon1, which was sequenced from a co-culture with the diatom Rhopalodia gibba collected from the Clark Fork River in Bonita, MT.

Overcoming NMR line broadening of nitrogen containing compounds: A simple solution.

This study presents a straightforward solution to the challenge of elucidating the structures of nitrogen containing compounds undergoing isomerization. When spectral line broadening occurs related to isomerization, be it prototropic tautomerism or bond rotations, this poses a significant obstacle to structural elucidation. By adding acids, we demonstrate a simple approach to overcome this issue and effectively sharpen NMR signals for acid stable prototropic tautomers as well as the conformational isomers containing a morpholine or piperazine ring.

The effectiveness of intradiscal corticosteroid injection for the treatment of chronic discovertebral low back pain: a systematic review.

OBJECTIVE: Determine the effectiveness of intradiscal corticosteroid injection (IDCI) for the treatment of discovertebral low back pain. DESIGN: Systematic review. POPULATION: Adults with chronic low back pain attributed to disc or vertebral end plate pain, as evidenced by positive provocation discography or Modic 1 or 2 changes on magnetic resonance imaging. INTERVENTION: Fluoroscopically guided or computed tomography-guided IDCI. COMPARISON: Sham/placebo procedure including intradiscal saline, anesthetic, discography alone, or other active treatment. OUTCOMES: Reduction in chronic low back pain reported on a visual analog scale or numeric rating scale and reduction in disability reported by a validated scale such as the Oswestry Disability Index. METHODS: Four reviewers independently assessed articles published before January 31, 2023, in Medline, Embase, CENTRAL, and CINAHL. The quality of evidence was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The risk of bias in randomized trials was evaluated with the Cochrane Risk of Bias tool (version 2). RESULTS: Of the 7806 unique records screened, 6 randomized controlled trials featuring 603 total participants ultimately met the inclusion criteria. In multiple randomized controlled trials, IDCI was found to reduce pain and disability for 1-6 months in those with Modic 1 and 2 changes but not in those selected by provocation discography. CONCLUSION: According to GRADE, there is low-quality evidence that IDCI reduces pain and disability for up to 6 months in individuals with chronic discovertebral low back pain as evidenced by Modic 1 and 2 changes but not in individuals selected by provocation discography. STUDY REGISTRATION: PROSPERO (CRD42021287421).

Hypoxemia in School-age Children Undergoing One-lung Ventilation: A Retrospective Cohort Study from the Multicenter Perioperative Outcomes Group.

BACKGROUND: Risk factors for hypoxemia in school-age children undergoing one-lung ventilation remain poorly understood. The hypothesis was that certain modifiable and nonmodifiable factors may be associated with increased risk of hypoxemia in school-age children undergoing one-lung ventilation and thoracic surgery. METHODS: The Multicenter Perioperative Outcomes Group database was queried for children 4 to 17 yr of age undergoing one-lung ventilation. Patients undergoing vascular or cardiac procedures were excluded. The original cohort was divided into two cohorts: 4 to 9 and 10 to 17 yr of age inclusive. All records were reviewed electronically for the primary outcome of hypoxemia during one-lung ventilation, which was defined as an oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or longer continuously, while severe hypoxemia was defined as Spo2 less than 90% for 5 min or longer. Potential modifiable and nonmodifiable risk factors associated with these outcomes were evaluated using separate multivariable least absolute shrinkage and selection operator regression analyses for each cohort. The covariates evaluated included age, extremes of weight, American Society of Anesthesiologists Physical Status of III or higher, duration of one-lung ventilation, preoperative Spo2 less than 98%, approach to one-lung ventilation, right operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (defined as tidal volume of 6 ml/kg or less and positive end-expiratory pressure of 4 cm H2O or greater for more than 80% of the duration of one-lung ventilation), and procedure type. RESULTS: The prevalence of hypoxemia in the 4- to 9-yr-old cohort and the 10- to 17-yr-old cohort was 24 of 228 (10.5% [95% CI, 6.5 to 14.5%]) and 76 of 1,012 (7.5% [95% CI, 5.9 to 9.1%]), respectively. The prevalence of severe hypoxemia in both cohorts was 14 of 228 (6.1% [95% CI, 3.0 to 9.3%]) and 47 of 1,012 (4.6% [95% CI, 3.3 to 5.8%]). Initial Spo2 less than 98% was associated with hypoxemia in the 4- to 9-yr-old cohort (odds ratio, 4.20 [95% CI, 1.61 to 6.29]). Initial Spo2 less than 98% (odds ratio, 2.76 [95% CI, 1.69 to 4.48]), extremes of weight (odds ratio, 2.18 [95% CI, 1.29 to 3.61]), and right-sided cases (odds ratio, 2.33 [95% CI, 1.41 to 3.92]) were associated with an increased risk of hypoxemia in the older cohort. Increasing age (1-yr increment; odds ratio, 0.88 [95% CI, 0.80 to 0.97]) was associated with a decreased risk of hypoxemia. CONCLUSIONS: An initial room air oxygen saturation of less than 98% was associated with an increased risk of hypoxemia in all children 4 to 17 yr of age. Extremes of weight, right-sided cases, and decreasing age were associated with an increased risk of hypoxemia in children 10 to 17 yr of age.

An Asymmetric Aromatic Finkelstein Reaction: A Platform for Remote Diarylmethane Desymmetrization.

A first-of-its-kind enantioselective aromatic Finkelstein reaction is disclosed for the remote desymmetrization of diarylmethanes. The reaction operates through a copper-catalyzed C-I bond-forming event, and high levels of enantioselectivity are achieved through the deployment of a tailored guanidinylated peptide ligand. Strategic use of transition-metal-mediated reactions enables the chemoselective modification of the aryl iodide products; thus, the synthesis of a diverse set of otherwise difficult-to-access diarylmethanes with excellent levels of selectivity is realized from a common intermediate. A mixed experimental/computational analysis of steric parameters and substrate conformations identifies the importance of remote conformational effects as a key to achieving high enantioselectivity in this desymmetrization reaction.

Mental health of help-seeking outpatients pre and post COVID-19: A real-world data, multicentre study.

OBJECTIVE: A great deal of research addresses the mental health implications of the COVID-19 pandemic for the general population. Little is known about the implications for mental health of help-seeking outpatients and for the effectiveness of mental health services. The present study investigated the mental health and treatment response of help-seeking outpatients before and during the COVID-19 pandemic. METHOD: Routine outcome monitoring data from 3706 clients in the United States and Northern Europe was analysed using multilevel modelling with global subjective well-being as the dependent variable. RESULTS: As opposed to before the pandemic, during the pandemic, well-being scores were significantly higher at intake and improvement throughout treatment was significantly smaller in the US sample, while both were comparable in the EU sample. CONCLUSION: Although there is also evidence of less effective treatments since the pandemic, no conclusive picture emerges that portrays the impact of the pandemic on mental health as uniform. More research is needed to elucidate the impact of the pandemic on the help-seeking population.

Data Science-Enabled Palladium-Catalyzed Enantioselective Aryl-Carbonylation of Sulfonimidamides.

New methods for the general asymmetric synthesis of sulfonimidamides are of great interest due to their applications in medicinal chemistry, agrochemical discovery, and academic research. We report a palladium-catalyzed cross-coupling method for the enantioselective aryl-carbonylation of sulfonimidamides. Using data science techniques, a virtual library of calculated bisphosphine ligand descriptors was used to guide reaction optimization by effectively sampling the catalyst chemical space. The optimized conditions identified using this approach provided the desired product in excellent yield and enantioselectivity. As the next step, a data science-driven strategy was also used to explore a diverse set of aryl and heteroaryl iodides, providing key information about the scope and limitations of the method. Furthermore, we tested a range of racemic sulfonimidamides for compatibility of this coupling partner. The developed method offers a general and efficient strategy for accessing enantioenriched sulfonimidamides, which should facilitate their application in industrial and academic settings.

Sharing FAIR monitoring program data improves discoverability and reuse.

Data resulting from environmental monitoring programs are valuable assets for natural resource managers, decision-makers, and researchers. These data are often collected to inform specific reporting needs or decisions with a specific timeframe. While program-oriented data and related publications are effective for meeting program goals, sharing well-documented data and metadata allows users to research aspects outside initial program intentions. As part of an effort to integrate data from four long-term large-scale US aquatic monitoring programs, we evaluated the original datasets against the FAIR (Findable, Accessible, Interoperable, Reusable) data principles and offer recommendations and lessons learned. Differences in data governance across these programs resulted in considerable effort to access and reuse the original datasets. Requirements, guidance, and resources available to support data publishing and documentation are inconsistent across agencies and monitoring programs, resulting in various data formats and storage locations that are not easily found, accessed, or reused. Making monitoring data FAIR will reduce barriers to data discovery and reuse. Programs are continuously striving to improve data management, data products, and metadata; however, provision of related tools, consistent guidelines and standards, and more resources to do this work is needed. Given the value of these data and the significant effort required to access and reuse them, actions and steps intended on improving data documentation and accessibility are described.

Tropical forests are approaching critical temperature thresholds.

The critical temperature beyond which photosynthetic machinery in tropical trees begins to fail averages approximately 46.7 °C (Tcrit)1. However, it remains unclear whether leaf temperatures experienced by tropical vegetation approach this threshold or soon will under climate change. Here we found that pantropical canopy temperatures independently triangulated from individual leaf thermocouples, pyrgeometers and remote sensing (ECOSTRESS) have midday peak temperatures of approximately 34 °C during dry periods, with a long high-temperature tail that can exceed 40 °C. Leaf thermocouple data from multiple sites across the tropics suggest that even within pixels of moderate temperatures, upper canopy leaves exceed Tcrit 0.01% of the time. Furthermore, upper canopy leaf warming experiments (+2, 3 and 4 °C in Brazil, Puerto Rico and Australia, respectively) increased leaf temperatures non-linearly, with peak leaf temperatures exceeding Tcrit 1.3% of the time (11% for more than 43.5 °C, and 0.3% for more than 49.9 °C). Using an empirical model incorporating these dynamics (validated with warming experiment data), we found that tropical forests can withstand up to a 3.9 ± 0.5 °C increase in air temperatures before a potential tipping point in metabolic function, but remaining uncertainty in the plasticity and range of Tcrit in tropical trees and the effect of leaf death on tree death could drastically change this prediction. The 4.0 °C estimate is within the 'worst-case scenario' (representative concentration pathway (RCP) 8.5) of climate change predictions2 for tropical forests and therefore it is still within our power to decide (for example, by not taking the RCP 6.0 or 8.5 route) the fate of these critical realms of carbon, water and biodiversity3,4.

On the Ability of the N-O Bond to Support a Stable Stereogenic Axis: Peptide-Catalyzed Atroposelective N-Oxidation.

During studies of atroposelective, peptide-catalyzed N-oxidations of pyridines, we observed lower-than-expected barriers to atropisomerization for these stereodynamic processes under the reaction conditions. Mechanistic studies indicate a hydrogen bond-assisted racemization mechanism intrinsic to both the starting materials and products. We also identified a protonation-dependent barrier to rotation that operates for the starting materials alone. Nonetheless, several substrates were amenable to atroposelective N-oxidations via kinetic resolution, yielding krel values of up to 12.6 and the isolation of one N-oxide with >99:1 er after recrystallization.

Catalytic Asymmetric Hydrogen Atom Transfer: Enantioselective Hydroamination of Alkenes.

We report a highly enantioselective radical-based hydroamination of enol esters with sulfonamides jointly catalyzed by an Ir photocatalyst, Brønsted base, and tetrapeptide thiol. This method is demonstrated for the formation of 23 protected ß-amino-alcohol products, achieving selectivities up to 97:3 er. The stereochemistry of the product is set through selective hydrogen atom transfer from the chiral thiol catalyst to a prochiral C-centered radical. Structure-selectivity relationships derived from structural variation of both the peptide catalyst and olefin substrate provide key insights into the development of an optimal catalyst. Experimental and computational mechanistic studies indicate that hydrogen-bonding, π-π stacking, and London dispersion interactions are contributing factors for substrate recognition and enantioinduction. These findings further the development of radical-based asymmetric catalysis and contribute to the understanding of the noncovalent interactions relevant to such transformations.