Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.442
Filter
1.
Science ; 385(6708): 517-521, 2024 Aug 02.
Article in English | MEDLINE | ID: mdl-39088605

ABSTRACT

Tropical glaciers have retreated over recent decades, but whether the magnitude of this retreat exceeds the bounds of Holocene fluctuations is unclear. We measured cosmogenic beryllium-10 and carbon-14 concentrations in recently exposed bedrock at the margin of four glaciers spanning the tropical Andes to reconstruct their past extents relative to today. Nuclide concentrations are near zero in almost all samples, suggesting that these locations were never exposed during the Holocene. Our data imply that many glaciers in the tropics are probably now smaller than they have been in at least 11,700 years, making the tropics the first large region where this milestone has been documented.

2.
Proc Natl Acad Sci U S A ; 121(33): e2400862121, 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39106311

ABSTRACT

Secreted signaling peptides are central regulators of growth, development, and stress responses, but specific steps in the evolution of these peptides and their receptors are not well understood. Also, the molecular mechanisms of peptide-receptor binding are only known for a few examples, primarily owing to the limited availability of protein structural determination capabilities to few laboratories worldwide. Plants have evolved a multitude of secreted signaling peptides and corresponding transmembrane receptors. Stress-responsive SERINE RICH ENDOGENOUS PEPTIDES (SCOOPs) were recently identified. Bioactive SCOOPs are proteolytically processed by subtilases and are perceived by the leucine-rich repeat receptor kinase MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2 (MIK2) in the model plant Arabidopsis thaliana. How SCOOPs and MIK2 have (co)evolved, and how SCOOPs bind to MIK2 are unknown. Using in silico analysis of 350 plant genomes and subsequent functional testing, we revealed the conservation of MIK2 as SCOOP receptor within the plant order Brassicales. We then leveraged AI-based structural modeling and comparative genomics to identify two conserved putative SCOOP-MIK2 binding pockets across Brassicales MIK2 homologues predicted to interact with the "SxS" motif of otherwise sequence-divergent SCOOPs. Mutagenesis of both predicted binding pockets compromised SCOOP binding to MIK2, SCOOP-induced complex formation between MIK2 and its coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1, and SCOOP-induced reactive oxygen species production, thus, confirming our in silico predictions. Collectively, in addition to revealing the elusive SCOOP-MIK2 binding mechanism, our analytic pipeline combining phylogenomics, AI-based structural predictions, and experimental biochemical and physiological validation provides a blueprint for the elucidation of peptide ligand-receptor perception mechanisms.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Ligands , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/genetics , Peptides/metabolism , Peptides/chemistry , Evolution, Molecular , Models, Molecular , Signal Transduction , Phosphotransferases
3.
Nat Ecol Evol ; 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39103674

ABSTRACT

Global change is associated with variable shifts in the annual production of aboveground plant biomass, suggesting localized sensitivities with unclear causal origins. Combining remotely sensed normalized difference vegetation index data since the 1980s with contemporary field data from 84 grasslands on 6 continents, we show a widening divergence in site-level biomass ranging from +51% to -34% globally. Biomass generally increased in warmer, wetter and species-rich sites with longer growing seasons and declined in species-poor arid areas. Phenological changes were widespread, revealing substantive transitions in grassland seasonal cycling. Grazing, nitrogen deposition and plant invasion were prevalent in some regions but did not predict overall trends. Grasslands are undergoing sizable changes in production, with implications for food security, biodiversity and carbon storage especially in arid regions where declines are accelerating.

4.
Ann Thorac Surg ; 2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39004198

ABSTRACT

BACKGROUND: We evaluated the individual contributions of rigid-plate fixation (RPF) and an enhanced recovery protocol (ERP) on postoperative pain, opioid use, and other outcomes after median sternotomy as they were sequentially adopted into practice. METHODS: This single-center, retrospective, case-cohort study compared outcomes between median sternotomy patients (all comers) who underwent operation before implementation of RPF or ERP ("controls"), patients closed with RPF before ERP implementation ("RPF-only"), and patients managed with RPF and ERP during early "RPF+ERP-2020" and late "RPF+ERP-2022" implementation. RESULTS: The analysis included 608 median sternotomy patients (mean age, 65.7 ± 10.8 years; 29.6% women). Of those, 59.2% were isolated coronary artery bypass grafting, 7.7% were isolated valve procedures, and the rest were mixed/concomitant procedures. Median in-hospital, postoperative opioid administration was 172.5 morphine milligram equivalents (MMEs) in the control cohort vs 0 MMEs for RPF+ERP-2022 (P < .0001), despite similar or slightly reduced patient-reported pain scores. The proportion of patients discharged directly to home was 66.2% for controls, 79.6% for RPF-only (P = .010), and 93.5% for RPF+ERP-2022 (P < .0001). Median opioids prescribed at discharge were 600 MMEs for controls and 0 for RPF+ERP-2020 and RPF+ERP-2022 (P < .0001). At discharge, 86.7% of RPF-only patients received prescription opioids vs 5% in RPF+ERP-2020 and 4.3% RPF+ERP-2022 (P < .0001). These outcomes occurred without increased readmissions. CONCLUSIONS: Systematic implementation of RPF and ERP was associated with a significant and clinically meaningful decrease in opioid use in this large, real-world patient population.

5.
New Phytol ; 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39073209

ABSTRACT

Mycorrhizal associations are key mutualisms that shape the structure of forest communities and multiple ecosystem functions. However, we lack a framework for predicting the varying dominance of distinct mycorrhizal associations in an integrated proxy of multifunctionality across ecosystems. Here, we used the datasets containing diversity of mycorrhizal associations and 18 ecosystem processes related to supporting, provisioning, and regulating services to examine how the dominance of ectomycorrhiza (EcM) associations affects ecosystem multifunctionality in subtropical mountain forests in Southwest China. Meanwhile, we synthesized the prevalence of EcM-dominant effects on ecosystem functioning in forest biomes. Our results demonstrated that elevation significantly modified the distributions of EcM trees and fungal dominance, which in turn influenced multiple functions simultaneously. Multifunctionality increased with increasing proportion of EcM associations, supporting the ectomycorrhizal-dominance hypothesis. Meanwhile, we observed that the impacts of EcM dominance on individual ecosystem functions exhibited different relationships among forest biomes. Our findings highlight the importance of ectomycorrhizal dominance in regulating multifunctionality in subtropical forests. However, this ectomycorrhizal feedback in shaping ecosystem functions cannot necessarily be generalized across forests. Therefore, we argue that the predictions for ecosystem multifunctionality in response to the shifts of mycorrhizal composition could vary across space and time.

6.
ACS Catal ; 14(14): 11034-11043, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39050902

ABSTRACT

Engineering sesquiterpene synthases to form predefined alternative products is a major challenge due to their diversity in cyclization mechanisms and our limited understanding of how amino acid changes affect the steering of these mechanisms. Here, we use a combination of atomistic simulation and site-directed mutagenesis to engineer a selina-4(15),7(11)-diene synthase (SdS) such that its final reactive carbocation is quenched by trapped active site water, resulting in the formation of a complex hydroxylated sesquiterpene (selin-7(11)-en-4-ol). Initially, the SdS G305E variant produced 20% selin-7(11)-en-4-ol. As suggested by modeling of the enzyme-carbocation complex, selin-7(11)-en-4-ol production could be further improved by varying the pH, resulting in selin-7(11)-en-4-ol becoming the major product (48%) at pH 6.0. We incorporated the SdS G305E variant along with genes from the mevalonate pathway into bacterial BL21(DE3) cells and demonstrated the production of selin-7(11)-en-4-ol at a scale of 10 mg/L in batch fermentation. These results highlight opportunities for the simulation-guided engineering of terpene synthases to produce predefined complex hydroxylated sesquiterpenes.

7.
Cogn Behav Neurol ; 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39069962

ABSTRACT

BACKGROUND: While the cognitive hallmark of typical Alzheimer's disease (AD) is impaired memory consolidation, increasing evidence suggests that the frontal lobes and associated executive functions are also impacted. OBJECTIVE: We examined two neurobehavioral executive function tasks and associations with cortical thickness in patients diagnosed with mild cognitive impairment (MCI), suspected AD dementia, and a healthy control group. METHODS: First, we compared group performances on a go/no-go (GNG) task and on Luria's Fist-Edge-Palm (FEP) motor sequencing task. We then examined correlations between neurobehavioral task performance and the thickness of frontal cortical regions, AD signature regions, broader unbiased brain regions, and white matter hyperintensities (WMH). RESULTS: Participants with MCI performed worse than healthy controls, but better than participants with suspected AD dementia on both tasks. Both GNG and FEP (to a slightly greater extent) tasks showed diffuse associations with most AD signature regions and multiple additional regions within the temporal, parietal, and occipital cortices. Similarly, both tasks showed significant associations with all other cognitive tasks examined. Of the frontal regions examined, only the middle frontal gyrus and pars opercularis were associated with performance on these tasks. Interactions between the precuneus and transtemporal gyri were most predictive of GNG task performance, while the interaction between superior temporal and lingual gyri was most predictive of FEP task performance. CONCLUSION: This study replicates difficulties with both GNG and FEP tasks in participants with MCI and AD dementia. Both tasks showed widespread associations with the cortical thickness of various brain structures rather than localizing to frontal regions, consistent with the diffuse nature of AD.

8.
Chem Sci ; 15(29): 11572-11583, 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-39055018

ABSTRACT

The Diels-Alder reaction is one of the most effective methods for the synthesis of substituted cyclohexenes. The development of protein catalysts for this reaction remains a major priority, affording new sustainable routes to high value target molecules. Whilst a small number of natural enzymes have been shown capable of catalysing [4 + 2] cycloadditions, there is a need for significant mechanistic understanding of how these prospective Diels-Alderases promote catalysis to underpin their development as biocatalysts for use in synthesis. Here we present a molecular description of the complete reaction cycle of the bona fide natural Diels-Alderase AbyU, which catalyses formation of the spirotetronate skeleton of the antibiotic abyssomicin C. This description is derived from X-ray crystallographic studies of AbyU in complex with a non-transformable synthetic substrate analogue, together with transient kinetic analyses of the AbyU catalysed reaction and computational reaction simulations. These studies reveal the mechanistic intricacies of this enzyme system and establish a foundation for the informed reengineering of AbyU and related biocatalysts.

9.
Eur J Cancer ; 209: 114239, 2024 Jul 21.
Article in English | MEDLINE | ID: mdl-39059184

ABSTRACT

BACKGROUND: The monarchE and NATALEE trials demonstrated the benefit of CDK4/6 inhibitor (CDK4/6i) therapy in adjuvant breast cancer (BC) treatment. Patient selection, based on clinical characteristics, delineated those at high (monarchE) and high/intermediate recurrence risk (NATALEE). This study employed a historical patient cohort to describe the proportion and prognosis of patients eligible for adjuvant CDK4/6i trials. METHODS: Between 2009 and 2011, 3529 patients were enrolled in the adjuvant PreFace clinical trial (NCT01908556). Eligibility criteria included postmenopausal patients with hormone receptor-positive (HRpos) BC for whom a five-year upfront therapy with letrozole was indicated. Patients were categorized into prognostic groups according to monarchE and NATALEE inclusion criteria, and their invasive disease-free survival (iDFS) and overall survival (OS) were assessed. RESULTS: Among 2891 HRpos patients, 384 (13.3 %) met the primary monarchE inclusion criteria. The majority (n = 261) qualified due to having ≥ 4 positive lymph nodes. For NATALEE, 915 out of 2886 patients (31.7 %) met the eligibility criteria, with 126 patients (13.7 %) being node-negative. Patients from monarchE with ≥ 4 positive lymph nodes and NATALEE with stage III BC exhibited the poorest prognosis (3-year iDFS rate 0.87). Patients ineligible for the trials demonstrated prognoses similar to the most favorable patient groups within the eligibility criteria. CONCLUSION: Patient populations eligible for monarchE and NATALEE trials differed. Nearly a third of the postmenopausal HRpos population, previously under upfront letrozole treatment, met the NATALEE prognostic eligibility criteria. As certain eligible groups had a prognosis similar to non-eligible patients, it might be interesting to explore additional patient groups for CDK4/6i therapy.

10.
Cogn Emot ; : 1-29, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39007902

ABSTRACT

Temporal context models (TCMs) have been influential in understanding episodic memory and its neural underpinnings. Recently, TCMs have been extended to explain emotional memory effects, one of the most clinically important findings in the field of memory research. This review covers recent advances in hypotheses for the neural representation of spatiotemporal context through the lens of TCMs, including their ability to explain the influence of emotion on episodic and temporal memory. In recent years, simplifying assumptions of "classical" TCMs - with exponential trace decay and the mechanism by which temporal context is recovered - have become increasingly clear. The review also outlines how recent advances could be incorporated into a future TCM, beyond classical assumptions, to integrate emotional modulation.

11.
J Thromb Haemost ; 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39019440

ABSTRACT

BACKGROUND: The X-linked bleeding disorder Hemophilia B, caused by mutation(s) in the coagulation factor IX (FIX) gene, leads to partial or total loss of its function requiring lifelong FIX replacement therapy. Although new recombinant FIX (rIX) therapeutics like albumin-fusion proteins (rIX-FP) enable longer plasma half-life and thus less frequent administration, the complexity of intravenous (IV) injection remains. OBJECTIVES: The study aims to characterize rIX-FP variants with anticipated enhanced specific activity, which would leverage rIX-FP's superior pharmacokinetic (PK) profile with beneficial characteristics for subcutaneous (SC) administration. METHODS: Two rIX-FP variants, R338L ("Padua-variant") and R338L/E410K, were characterized in vitro. PK profiles of FIX antigen and activity levels were evaluated in FIX-deficient mice after IV and SC administration of these variants (dosing based on antigen levels). The efficacy of the most promising variant was tested after IV and SC administration (dosing based on activity) in a tail-clip bleeding model. A marketed wildtype (WT) rIX-FP product served as the comparator. RESULTS: Both rIX-FP variants showed a 4- to 5-fold increase in specific activity in vitro compared to rIX(WT)-FP, whilst FXIa-mediated activation was the fastest for rIX(WT)-FP and rIX(R338L)-FP. Compared to rIX(WT)-FP and rIX(R338L/E410K)-FP, rIX(R338L)-FP exhibited higher FIX activity exposure after IV and SC administration, and demonstrated comparable efficacy towards rIX(WT)-FP in reducing bleeding time and blood loss in FIX-deficient mice requiring ∼4 times lower protein amount. CONCLUSIONS: rIX(R338L)-FP was shown to be a promising candidate for SC administration, exhibiting increased specific activity combined with higher activity-based exposure, and indicating efficacy at lower protein dose.

12.
Sensors (Basel) ; 24(13)2024 Jun 29.
Article in English | MEDLINE | ID: mdl-39001004

ABSTRACT

The survival and growth of young plants hinge on various factors, such as seed quality and environmental conditions. Assessing seedling potential/vigor for a robust crop yield is crucial but often resource-intensive. This study explores cost-effective imaging techniques for rapid evaluation of seedling vigor, offering a practical solution to a common problem in agricultural research. In the first phase, nine lettuce (Lactuca sativa) cultivars were sown in trays and monitored using chlorophyll fluorescence imaging thrice weekly for two weeks. The second phase involved integrating embedded computers equipped with cameras for phenotyping. These systems captured and analyzed images four times daily, covering the entire growth cycle from seeding to harvest for four specific cultivars. All resulting data were promptly uploaded to the cloud, allowing for remote access and providing real-time information on plant performance. Results consistently showed the 'Muir' cultivar to have a larger canopy size and better germination, though 'Sparx' and 'Crispino' surpassed it in final dry weight. A non-linear model accurately predicted lettuce plant weight using seedling canopy size in the first study. The second study improved prediction accuracy with a sigmoidal growth curve from multiple harvests (R2 = 0.88, RMSE = 0.27, p < 0.001). Utilizing embedded computers in controlled environments offers efficient plant monitoring, provided there is a uniform canopy structure and minimal plant overlap.


Subject(s)
Germination , Lactuca , Seedlings , Lactuca/growth & development , Lactuca/physiology , Germination/physiology , Seedlings/growth & development , Seedlings/physiology , Chlorophyll/analysis , Chlorophyll/metabolism , Seeds/growth & development , Seeds/physiology
13.
Sensors (Basel) ; 24(13)2024 Jun 29.
Article in English | MEDLINE | ID: mdl-39001005

ABSTRACT

Salinity stress is a common challenge in plant growth, impacting seed quality, germination, and general plant health. Sodium chloride (NaCl) ions disrupt membranes, causing ion leakage and reducing seed viability. Gibberellic acid (GA3) treatments have been found to promote germination and mitigate salinity stress on germination and plant growth. 'Bauer' and 'Muir' lettuce (Lactuca sativa) seeds were soaked in distilled water (control), 100 mM NaCl, 100 mM NaCl + 50 mg/L GA3, and 100 mM NaCl + 150 mg/L GA3 in Petri dishes and kept in a dark growth chamber at 25 °C for 24 h. After germination, seedlings were monitored using embedded cameras, capturing red, green, and blue (RGB) images from seeding to final harvest. Despite consistent germination rates, 'Bauer' seeds treated with NaCl showed reduced germination. Surprisingly, the 'Muir' cultivar's final dry weight differed across treatments, with the NaCl and high GA3 concentration combination yielding the poorest results (p < 0.05). This study highlights the efficacy of GA3 applications in improving germination rates. However, at elevated concentrations, it induced excessive hypocotyl elongation and pale seedlings, posing challenges for two-dimensional imaging. Nonetheless, a sigmoidal regression model using projected canopy size accurately predicted dry weight across growth stages and cultivars, emphasizing its reliability despite treatment variations (R2 = 0.96, RMSE = 0.11, p < 0.001).


Subject(s)
Germination , Gibberellins , Lactuca , Seedlings , Seeds , Gibberellins/pharmacology , Lactuca/growth & development , Lactuca/drug effects , Seedlings/drug effects , Seedlings/growth & development , Germination/drug effects , Germination/physiology , Seeds/drug effects , Seeds/growth & development , Salt Stress/drug effects , Sodium Chloride/pharmacology
14.
Sensors (Basel) ; 24(13)2024 Jun 29.
Article in English | MEDLINE | ID: mdl-39001015

ABSTRACT

The decline in seed quality over time due to natural aging or mishandling requires assessing seed vigor for resilience in adverse conditions. Accelerated aging (AA) methods simulate seed deterioration by subjecting seeds to high temperatures and humidity. Saturated salt accelerated aging (SSAA) is an AA method adopted for small seeds like lettuce (Lactuca sativa). In this study, we subjected seeds of two lettuce cultivars ('Muir' and 'Bauer') to SSAA by sealing them in a box containing 40 g/100 mL of a sodium chloride (NaCl) solution in a dark growth chamber at 41 °C for 24, 48, and 72 h with a control. We monitored their vigor using embedded computer cameras, tracking the projected canopy size (PCS) daily from sowing to harvest. The cultivar 'Muir' exhibited consistent PCS values across the treatments, while 'Bauer' showed PCS variations, with notable declines after prolonged aging. The germination rates dropped significantly after 48 and 72 h of SSAA. A nonlinear regression model revealed a strong relationship between PCS and shoot dry weight across harvests and cultivars (R2 = 0.93, RMSE = 0.15, p < 0.001). The research found that the projected canopy size and shoot dry weight increased over time with significant differences in treatments for the cultivar 'Bauer' but not for 'Muir,' with the canopy size being a strong predictor of dry weight and no significant impact from the SSAA treatments. This study highlights cultivar-specific responses to aging and demonstrates the efficacy of our imaging tool in predicting lettuce dry weight despite treatment variations. Understanding how aging affects different lettuce varieties is crucial for seed management and crop sustainability.


Subject(s)
Germination , Lactuca , Seedlings , Seeds , Lactuca/growth & development , Lactuca/physiology , Germination/physiology , Seeds/growth & development , Seeds/physiology , Seedlings/growth & development , Seedlings/physiology
15.
Nat Catal ; 7(5): 499-509, 2024.
Article in English | MEDLINE | ID: mdl-38828429

ABSTRACT

Epistasis, the non-additive effect of mutations, can provide combinatorial improvements to enzyme activity that substantially exceed the gains from individual mutations. Yet the molecular mechanisms of epistasis remain elusive, undermining our ability to predict pathogen evolution and engineer biocatalysts. Here we reveal how directed evolution of a ß-lactamase yielded highly epistatic activity enhancements. Evolution selected four mutations that increase antibiotic resistance 40-fold, despite their marginal individual effects (≤2-fold). Synergistic improvements coincided with the introduction of super-stochiometric burst kinetics, indicating that epistasis is rooted in the enzyme's conformational dynamics. Our analysis reveals that epistasis stemmed from distinct effects of each mutation on the catalytic cycle. The initial mutation increased protein flexibility and accelerated substrate binding, which is rate-limiting in the wild-type enzyme. Subsequent mutations predominantly boosted the chemical steps by fine-tuning substrate interactions. Our work identifies an overlooked cause for epistasis: changing the rate-limiting step can result in substantial synergy that boosts enzyme activity.

16.
J Surg Oncol ; 130(2): 284-292, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38828742

ABSTRACT

BACKGROUND: Neoadjuvant chemotherapy (NAC) use for pancreatic ductal adenocarcinoma (PDAC) has increased, but some patients never get resection following NAC. METHODS: Data from January 2012 to December 2019 for all clinically resectable patients across two health networks were utilized, as well as data from the ACS NCDB registry. Univariate testing, multivariable logistic regression, and survival analyses were employed to evaluate failure to resection after neo-adjuvant chemotherapy. RESULTS: Of the 10 007 registry patients eligible for resection, the resected group was younger (64.6 vs. 69.5 years; p < 0.001) and had a slightly lower mean comorbidity index (0.41 vs. 0.45; p < 0.001) than the nonsurgical group. The nonsurgical group was composed of a higher percentage of Black and Hispanic patients (17.5 vs. 13.1%; p < 0.001). After adjusting for age and comorbidities, the factors associated with decreased probability of resection after NAC were evaluation at a community hospital (OR 2.4), Black or Hispanic race (OR 1.6), areas of increased high school drop-out rates (OR 1.4), and lack of private health insurance (OR 1.3). The median overall survival for nonsurgery was markedly worse than the surgical cohort (10.6 vs. 26.6 months; p < 0.001). The most frequent reasons for a lack of definitive resection were operative upstaging to unresectable (39.6%), patient preference (14.5%), progression on NAC (13.2%), deconditioning or comorbidity severity (12.5%), and nonreferral to a surgeon (8.8%). CONCLUSIONS: Racial, economic, and educational disparities have a considerable influence on the successful completion of a neoadjuvant approach for resectable PDAC. A comprehensive closed or highly collaborative/communicative multidisciplinary neoadjuvant program is optimal for treatment success and completion.


Subject(s)
Neoadjuvant Therapy , Pancreatectomy , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/surgery , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/therapy , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/mortality , Male , Female , Aged , Middle Aged , Carcinoma, Pancreatic Ductal/therapy , Carcinoma, Pancreatic Ductal/surgery , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/mortality , Carcinoma, Pancreatic Ductal/drug therapy , Chemotherapy, Adjuvant , Adenocarcinoma/pathology , Adenocarcinoma/therapy , Adenocarcinoma/surgery , Adenocarcinoma/mortality , Adenocarcinoma/drug therapy , Survival Rate , Registries , Follow-Up Studies , Prognosis , United States
17.
Ecol Evol ; 14(6): e11599, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38882534

ABSTRACT

Duckweeds, including the common duckweed Lemna minor, are increasingly used to test eco-evolutionary theories. Yet, despite its popularity and near-global distribution, the understanding of its population structure (and genetic variation therein) is still limited. It is essential that this is resolved, because of the impact genetic diversity has on experimental responses and scientific understanding. Through whole-genome sequencing, we assessed the genetic diversity and population genomic structure of 23 natural Lemna spp. populations from their natural range in Switzerland. We used two distinct analytical approaches, a reference-free kmer approach and the classical reference-based one. Two genetic clusters were identified across the described species distribution of L. minor, surprisingly corresponding to species-level divisions. The first cluster contained the targeted L. minor individuals and the second contained individuals from a cryptic species: Lemna japonica. Within the L. minor cluster, we identified a well-defined population structure with little intra-population genetic diversity (i.e., within ponds) but high inter-population diversity (i.e., between ponds). In L. japonica, the population structure was significantly weaker and genetic variation between a subset of populations was as low as within populations. This study revealed that L. japonica is more widespread than previously thought. Our findings signify that thorough genotype-to-phenotype analyses are needed in duckweed experimental ecology and evolution.

18.
Article in English | MEDLINE | ID: mdl-38865172

ABSTRACT

Two bacteria, UG2_1T and UG2_2, were isolated from the gill tissues of the mangrove fiddler crab Cranuca inversa collected on the east coast of the Red Sea (Thuwal, Saudi Arabia). The cells are Gram-negative, rod-shaped, orange-pigmented, motile by gliding with no flagella, strictly aerobic, and grow at 20-37 °C (optimum, 28-35 °C), at pH 5.0-9.0 (optimum, pH 6.0-7.0), and with 1-11 % (w/v) NaCl (optimum, 2-4 %). They were positive for oxidase and catalase activity. Phylogenetic analysis based on 16S rRNA gene sequences indicated that isolates UG2_1T and UG2_2 belong to the genus Mangrovimonas, showing the highest similarity to Mangrovimonas spongiae HN-E26T (99.4 %). Phylogenomic analysis based on the whole genomes, independently using 49 and 120 concatenated genes, showed that strains UG2_1T and UG2_2 formed a monophyletic lineage in a different cluster from other type strain species within the genus Mangrovimonas. The genome sizes were 3.08 and 3.07 Mbp for UG2_1T and UG2_2, respectively, with a G+C content of 33.8 mol% for both strains. Values of average nucleotide identity and digital DNA-DNA hybridization between the strains and closely related species were 91.0 and 43.5 %, respectively. Chemotaxonomic analysis indicated that both strains had iso-C15 : 0 and iso-C15 : 1 G as dominant fatty acids, and the primary respiratory quinone was identified as MK-6. The major polar lipids comprised phosphatidylethanolamine, one unidentified glycolipid, one unidentified phospholipid, two unidentified aminolipids, and four unidentified lipids. Based on phylogenetic, phylogenomic, genome relatedness, phenotypic, and chemotaxonomical data, the two isolates represent a novel species within the genus Mangrovimonas, with the proposed name Mangrovimonas cancribranchiae sp. nov., and the type strain UG2_1T (=KCTC 102158T=DSM 117025T).


Subject(s)
Bacterial Typing Techniques , Base Composition , Brachyura , DNA, Bacterial , Fatty Acids , Gills , Nucleic Acid Hybridization , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , RNA, Ribosomal, 16S/genetics , Fatty Acids/analysis , DNA, Bacterial/genetics , Indian Ocean , Animals , Gills/microbiology , Brachyura/microbiology , Saudi Arabia , Wetlands , Vitamin K 2/analogs & derivatives , Vitamin K 2/analysis , Phospholipids/analysis
20.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38771243

ABSTRACT

Variability in brain structure is associated with the capacity for behavioral change. However, a causal link between specific brain areas and behavioral change (such as motor learning) has not been demonstrated. We hypothesized that greater gray matter volume of a primary motor cortex (M1) area active during a hand motor learning task is positively correlated with subsequent learning of the task, and that the disruption of this area blocks learning of the task. Healthy participants underwent structural MRI before learning a skilled hand motor task. Next, participants performed this learning task during fMRI to determine M1 areas functionally active during this task. This functional ROI was anatomically constrained with M1 boundaries to create a group-level "Active-M1" ROI used to measure gray matter volume in each participant. Greater gray matter volume in the left hemisphere Active-M1 ROI was related to greater motor learning in the corresponding right hand. When M1 hand area was disrupted with repetitive transcranial stimulation (rTMS), learning of the motor task was blocked, confirming its causal link to motor learning. Our combined imaging and rTMS approach revealed greater cortical volume in a task-relevant M1 area is causally related to learning of a hand motor task in healthy humans.


Subject(s)
Gray Matter , Hand , Learning , Magnetic Resonance Imaging , Motor Cortex , Transcranial Magnetic Stimulation , Humans , Motor Cortex/physiology , Motor Cortex/diagnostic imaging , Male , Female , Hand/physiology , Learning/physiology , Adult , Young Adult , Gray Matter/physiology , Gray Matter/diagnostic imaging , Motor Skills/physiology , Brain Mapping , Functional Laterality/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...