Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 2.660
Filter
Add more filters

Publication year range
1.
Nature ; 616(7957): 443-447, 2023 04.
Article in English | MEDLINE | ID: mdl-36858073

ABSTRACT

Although no known asteroid poses a threat to Earth for at least the next century, the catalogue of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation1,2. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid1-3. A test of kinetic impact technology was identified as the highest-priority space mission related to asteroid mitigation1. NASA's Double Asteroid Redirection Test (DART) mission is a full-scale test of kinetic impact technology. The mission's target asteroid was Dimorphos, the secondary member of the S-type binary near-Earth asteroid (65803) Didymos. This binary asteroid system was chosen to enable ground-based telescopes to quantify the asteroid deflection caused by the impact of the DART spacecraft4. Although past missions have utilized impactors to investigate the properties of small bodies5,6, those earlier missions were not intended to deflect their targets and did not achieve measurable deflections. Here we report the DART spacecraft's autonomous kinetic impact into Dimorphos and reconstruct the impact event, including the timeline leading to impact, the location and nature of the DART impact site, and the size and shape of Dimorphos. The successful impact of the DART spacecraft with Dimorphos and the resulting change in the orbit of Dimorphos7 demonstrates that kinetic impactor technology is a viable technique to potentially defend Earth if necessary.

2.
Nature ; 604(7907): 757-762, 2022 04.
Article in English | MEDLINE | ID: mdl-35418682

ABSTRACT

Adhesion G-protein-coupled receptors (aGPCRs) are characterized by the presence of auto-proteolysing extracellular regions that are involved in cell-cell and cell-extracellular matrix interactions1. Self cleavage within the aGPCR auto-proteolysis-inducing (GAIN) domain produces two protomers-N-terminal and C-terminal fragments-that remain non-covalently attached after receptors reach the cell surface1. Upon dissociation of the N-terminal fragment, the C-terminus of the GAIN domain acts as a tethered agonist (TA) peptide to activate the seven-transmembrane domain with a mechanism that has been poorly understood2-5. Here we provide cryo-electron microscopy snapshots of two distinct members of the aGPCR family, GPR56 (also known as ADGRG1) and latrophilin 3 (LPHN3 (also known as ADGRL3)). Low-resolution maps of the receptors in their N-terminal fragment-bound state indicate that the GAIN domain projects flexibly towards the extracellular space, keeping the encrypted TA peptide away from the seven-transmembrane domain. High-resolution structures of GPR56 and LPHN3 in their active, G-protein-coupled states, reveal that after dissociation of the extracellular region, the decrypted TA peptides engage the seven-transmembrane domain core with a notable conservation of interactions that also involve extracellular loop 2. TA binding stabilizes breaks in the middle of transmembrane helices 6 and 7 that facilitate aGPCR coupling and activation of heterotrimeric G proteins. Collectively, these results enable us to propose a general model for aGPCR activation.


Subject(s)
Receptors, G-Protein-Coupled , Signal Transduction , Cell Adhesion , Cell Membrane/metabolism , Cryoelectron Microscopy , Humans , Peptides/chemistry , Protein Binding , Receptors, G-Protein-Coupled/metabolism , Receptors, Peptide
3.
Proc Natl Acad Sci U S A ; 121(22): e2401185121, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38768340

ABSTRACT

The origin of the German cockroach, Blattella germanica, is enigmatic, in part because it is ubiquitous worldwide in human-built structures but absent from any natural habitats. The first historical records of this species are from ca. 250 years ago (ya) from central Europe (hence its name). However, recent research suggests that the center of diversity of the genus is Asian, where its closest relatives are found. To solve this paradox, we sampled genome-wide markers of 281 cockroaches from 17 countries across six continents. We confirm that B. germanica evolved from the Asian cockroach Blattella asahinai approximately 2,100 ya, probably by adapting to human settlements in India or Myanmar. Our genomic analyses reconstructed two primary global spread routes, one older, westward route to the Middle East coinciding with various Islamic dynasties (~1,200 ya), and another younger eastward route coinciding with the European colonial period (~390 ya). While Europe was not central to the early domestication and spread of the German cockroach, European advances in long-distance transportation and temperature-controlled housing were likely important for the more recent global spread, increasing chances of successful dispersal to and establishment in new regions. The global genetic structure of German cockroaches further supports our model, as it generally aligns with geopolitical boundaries, suggesting regional bridgehead populations established following the advent of international commerce.


Subject(s)
Blattellidae , Animals , Blattellidae/genetics , Phylogeny , Europe , Biological Evolution
4.
Proc Natl Acad Sci U S A ; 121(8): e2319696121, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38346181

ABSTRACT

The phylogeny and divergence timing of the Neoavian radiation remain controversial despite recent progress. We analyzed the genomes of 124 species across all Neoavian orders, using data from 25,460 loci spanning four DNA classes, including 5,756 coding sequences, 12,449 conserved nonexonic elements, 4,871 introns, and 2,384 intergenic segments. We conducted a comprehensive sensitivity analysis to account for the heterogeneity across different DNA classes, leading to an optimal tree of Neoaves with high resolution. This phylogeny features a novel Neoavian dichotomy comprising two monophyletic clades: a previously recognized Telluraves (land birds) and a newly circumscribed Aquaterraves (waterbirds and relatives). Molecular dating analyses with 20 fossil calibrations indicate that the diversification of modern birds began in the Late Cretaceous and underwent a constant and steady radiation across the KPg boundary, concurrent with the rise of angiosperms as well as other major Cenozoic animal groups including placental and multituberculate mammals. The KPg catastrophe had a limited impact on avian evolution compared to the Paleocene-Eocene Thermal Maximum, which triggered a rapid diversification of seabirds. Our findings suggest that the evolution of modern birds followed a slow process of gradualism rather than a rapid process of punctuated equilibrium, with limited interruption by the KPg catastrophe. This study places bird evolution into a new context within vertebrates, with ramifications for the evolution of the Earth's biota.


Subject(s)
Fossils , Magnoliopsida , Pregnancy , Female , Animals , Magnoliopsida/genetics , Placenta , Phylogeny , Birds/genetics , Mammals/genetics , DNA, Mitochondrial/genetics , Biological Evolution
5.
PLoS Biol ; 21(8): e3002251, 2023 08.
Article in English | MEDLINE | ID: mdl-37607211

ABSTRACT

Modern advances in DNA sequencing hold the promise of facilitating descriptions of new organisms at ever finer precision but have come with challenges as the major Codes of bionomenclature contain poorly defined requirements for species and subspecies diagnoses (henceforth, species diagnoses), which is particularly problematic for DNA-based taxonomy. We, the commissioners of the International Commission on Zoological Nomenclature, advocate a tightening of the definition of "species diagnosis" in future editions of Codes of bionomenclature, for example, through the introduction of requirements for specific information on the character states of differentiating traits in comparison with similar species. Such new provisions would enhance taxonomic standards and ensure that all diagnoses, including DNA-based ones, contain adequate taxonomic context. Our recommendations are intended to spur discussion among biologists, as broad community consensus is critical ahead of the implementation of new editions of the International Code of Zoological Nomenclature and other Codes of bionomenclature.


Subject(s)
DNA , DNA/genetics , Phenotype , Sequence Analysis, DNA
6.
Proc Natl Acad Sci U S A ; 120(43): e2307340120, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37844245

ABSTRACT

Echolocation, the detection of objects by means of sound waves, has evolved independently in diverse animals. Echolocators include not only mammals such as toothed whales and yangochiropteran and rhinolophoid bats but also Rousettus fruit bats, as well as two bird lineages, oilbirds and swiftlets. In whales and yangochiropteran and rhinolophoid bats, positive selection and molecular convergence has been documented in key hearing-related genes, such as prestin (SLC26A5), but few studies have examined these loci in other echolocators. Here, we examine patterns of selection and convergence in echolocation-related genes in echolocating birds and Rousettus bats. Fewer of these loci were under selection in Rousettus or birds compared with classically recognized echolocators, and elevated convergence (compared to outgroups) was not evident across this gene set. In certain genes, however, we detected convergent substitutions with potential functional relevance, including convergence between Rousettus and classic echolocators in prestin at a site known to affect hair cell electromotility. We also detected convergence between Yangochiroptera, Rhinolophidea, and oilbirds in TMC1, an important mechanosensory transduction channel in vertebrate hair cells, and observed an amino acid change at the same site within the pore domain. Our results suggest that although most proteins implicated in echolocation in specialized mammals may not have been recruited in birds or Rousettus fruit bats, certain hearing-related loci may have undergone convergent functional changes. Investigating adaptations in diverse echolocators will deepen our understanding of this unusual sensory modality.


Subject(s)
Chiroptera , Echolocation , Animals , Chiroptera/physiology , Phylogeny , Evolution, Molecular , Mammals/genetics , Hearing/genetics , Whales/physiology , Birds/genetics , Echolocation/physiology
7.
PLoS Genet ; 19(1): e1010551, 2023 01.
Article in English | MEDLINE | ID: mdl-36656838

ABSTRACT

Human activities have precipitated a rise in the levels of introgressive gene flow among animals. The investigation of conspecific populations at different time points may shed light on the magnitude of human-mediated introgression. We used the red junglefowl Gallus gallus, the wild ancestral form of the chicken, as our study system. As wild junglefowl and domestic chickens readily admix, conservationists fear that domestic introgression into junglefowl may compromise their wild genotype. By contrasting the whole genomes of 51 chickens with 63 junglefowl from across their natural range, we found evidence of a loss of the wild genotype across the Anthropocene. When comparing against the genomes of junglefowl from approximately a century ago using rigorous ancient-DNA protocols, we discovered that levels of domestic introgression are not equal among and within modern wild populations, with the percentage of domestic ancestry around 20-50%. We identified a number of domestication markers in which chickens are deeply differentiated from historic junglefowl regardless of breed and/or geographic provenance, with eight genes under selection. The latter are involved in pathways dealing with development, reproduction and vision. The wild genotype is an allelic reservoir that holds most of the genetic diversity of G. gallus, a species which is immensely important to human society. Our study provides fundamental genomic infrastructure to assist in efforts to prevent a further loss of the wild genotype through introgression of domestic alleles.


Subject(s)
Chickens , Genetics, Population , Genome , Animals , Chickens/genetics , Gene Flow , Genome/genetics , Genotype , Phylogeny
8.
Proc Natl Acad Sci U S A ; 120(45): e2306899120, 2023 Nov 07.
Article in English | MEDLINE | ID: mdl-37903262

ABSTRACT

Taxonomic data are a scientific common. Unlike nomenclature, which has strong governance institutions, there are currently no generally accepted governance institutions for the compilation of taxonomic data into an accepted global list. This gap results in challenges for conservation, ecological research, policymaking, international trade, and other areas of scientific and societal importance. Consensus on a global list and its management requires effective governance and standards, including agreed mechanisms for choosing among competing taxonomies and partial lists. However, governance frameworks are currently lacking, and a call for governance in 2017 generated critical responses. Any governance system to which compliance is voluntary requires a high level of legitimacy and credibility among those by and for whom it is created. Legitimacy and credibility, in turn, require adequate and credible consultation. Here, we report on the results of a global survey of taxonomists, scientists from other disciplines, and users of taxonomy designed to assess views and test ideas for a new system of taxonomic list governance. We found a surprisingly high degree of agreement on the need for a global list of accepted species and their names, and consistent views on what such a list should provide to users and how it should be governed. The survey suggests that consensus on a mechanism to create, manage, and govern a single widely accepted list of all the world's species is achievable. This finding was unexpected given past controversies about the merits of list governance.


Subject(s)
Commerce , Physicians , Humans , Internationality
9.
Proc Natl Acad Sci U S A ; 120(51): e2309034120, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38079550

ABSTRACT

There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared. We compiled more than 200 y of records for 10 major taxonomic groups in Singapore (>50,000 individual records; >3,000 species), and we estimated extinction rates using recently developed and novel statistical models that account for "dark extinctions," i.e., extinctions of undiscovered species. The estimated overall extinction rate was 37% (95% CI [31 to 42%]). Extrapolating our Singapore observations to a future business-as-usual deforestation scenario for Southeast Asia suggests that 18% (95% CI [16 to 22%]) of species will be lost regionally by 2100. Our extinction estimates for Singapore and Southeast Asia are a factor of two lower than previous estimates that also attempted to account for dark extinctions. However, we caution that particular groups such as large mammals, forest-dependent birds, orchids, and butterflies are disproportionately vulnerable.


Subject(s)
Butterflies , Animals , Singapore , Conservation of Natural Resources , Extinction, Biological , Biodiversity , Mammals
10.
Circulation ; 2024 Oct 27.
Article in English | MEDLINE | ID: mdl-39462291

ABSTRACT

BACKGROUND: The Placebo-controlled Trial of Percutaneous Coronary Intervention for the Relief of Stable Angina (ORBITA-2) provided evidence for the role of percutaneous coronary intervention (PCI) for angina relief in stable coronary artery disease (CAD). Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are often used to guide PCI, however their ability to predict placebo-controlled angina improvement is unknown. METHODS: Participants with angina, ischemia, and stable CAD were enrolled and antianginal medications were stopped. Participants reported angina episodes daily for 2 weeks using the ORBITA-app. At the research angiogram, FFR and iFR were measured. After sedation and auditory isolation, participants were randomized to PCI or placebo, before entering a 12-week blinded follow-up phase with daily angina reporting. The ability of FFR and iFR, analyzed as continuous variables, to predict the placebo-controlled effect of PCI, was tested using Bayesian proportional odds modelling. RESULTS: Invasive physiology data were available in 279 patients (140 PCI and 139 placebo). The median (IQR) age was 65 years (59.0 to 70.5) and 223 (79.9%) were male. Median FFR was 0.60 (0.46 to 0.73) and median iFR was 0.76 (0.50 to 0.86). The lower the FFR or iFR, the greater the placebo-controlled improvement with PCI across all endpoints. There was strong evidence that a patient with an FFR at the lower quartile would have a greater placebo-controlled improvement in angina symptom score with PCI than a patient at the upper quartile (FFR 0.46 vs. 0.73: OR 2.01, 95% CrI 1.79 to 2.26, Pr(Interaction)>99.9%). Similarly, there was strong evidence that a patient with an iFR at the lower quartile would have a greater placebo controlled improvement in angina symptom score with PCI than a patient with an iFR at the upper quartile (iFR 0.50 vs. 0.86: OR 2.13, 95% CrI 1.87 to 2.45, Pr(Interaction) >99.9%). The relationship between benefit and physiology was seen in both Rose angina and Rose nonangina. CONCLUSIONS: Physiological stenosis severity, as measured by FFR and iFR, predicts placebo-controlled angina relief from PCI. Invasive coronary physiology can be used to target PCI to those patients who are most likely to experience benefit.

11.
Mol Biol Evol ; 2024 Oct 24.
Article in English | MEDLINE | ID: mdl-39447047

ABSTRACT

Many highly recognisable species lack genetic data important for conservation due to neglect over their hyperabundance. This likely applies to the Sulphur-crested Cockatoo (Cacatua galerita), one of the world's most iconic parrots. The species is native to Australia, New Guinea and some surrounding Melanesian islands. Four subspecies are currently recognised based on morphology. Australian subspecies and populations are abundant, but several factors threaten those in New Guinea and Melanesia. Genetic data from natural populations are scarce - information that is vital to identifying evolutionarily significant units (ESUs) important for modern conservation planning. We used whole-genome resequencing to investigate patterns of differentiation, evolutionary affinities and demographic history across C. galerita's range to assess whether currently recognised subspecies represent ESUs. We complement this with an assessment of bioacoustic variation across the species' distribution range. Our results point to C. galerita sensu lato (s.l.) comprising two species. We restrict C. galerita sensu stricto (s.s.) to populations in Australia and the Trans-Fly ecodomain of southern New Guinea. The second species, recognised here as Cacatua triton, likely occurs over much of the rest of New Guinea. Restricting further discussion of intraspecific diversity in C. triton, we show that within C. galerita s.s. two ESUs exist, which align to Cacatua galerita galerita in eastern Australia and southern New Guinea and Cacatua galerita fitzroyi in northern and north-western Australia. We suggest that the evolution of these species and ESUs are linked to Middle and Late Pleistocene glacial cycles and their effects on sea level and preferential habitats. We argue that conservation assessments need updating, protection of preferential forest and woodland habitats are important and reintroductions require careful management to avoid possible negative hybridization effects of non-complementary lineages.

12.
Mol Biol Evol ; 41(3)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38318973

ABSTRACT

Mountains are the world's most important centers of biodiversity. The Sino-Himalayan Mountains are global biodiversity hotspot due to their extremely high species richness and endemicity. Ample research investigated the impact of the Qinghai-Tibet Plateau uplift and Quaternary glaciations in driving species diversification in plants and animals across the Sino-Himalayan Mountains. However, little is known about the role of landscape heterogeneity and other environmental features in driving diversification in this region. We utilized whole genomes and phenotypic data in combination with landscape genetic approaches to investigate population structure, demography, and genetic diversity in a forest songbird species native to the Sino-Himalayan Mountains, the red-billed leiothrix (Leiothrix lutea). We identified 5 phylogeographic clades, including 1 in the East of China, 1 in Yunnan, and 3 in Tibet, roughly consistent with differences in song and plumage coloration but incongruent with traditional subspecies boundaries. Isolation-by-resistance model best explained population differentiation within L. lutea, with extensive secondary contact after allopatric isolation leading to admixture among clades. Ecological niche modeling indicated relative stability in the extent of suitable distribution areas of the species across Quaternary glacial cycles. Our results underscore the importance of mountains in the diversification of this species, given that most of the distinct genetic clades are concentrated in a relatively small area in the Sino-Himalayan Mountain region, while a single shallow clade populates vast lower-lying areas to the east. This study highlights the crucial role of landscape heterogeneity in promoting differentiation and provides a deep genomic perspective on the mechanisms through which diversity hotspots form.


Subject(s)
Genetic Drift , Passeriformes , Animals , China , Phylogeography , Forests , Passeriformes/genetics , Phylogeny , Genetic Variation
13.
Lancet ; 403(10436): 1543-1553, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38604209

ABSTRACT

BACKGROUND: The coronary sinus reducer (CSR) is proposed to reduce angina in patients with stable coronary artery disease by improving myocardial perfusion. We aimed to measure its efficacy, compared with placebo, on myocardial ischaemia reduction and symptom improvement. METHODS: ORBITA-COSMIC was a double-blind, randomised, placebo-controlled trial conducted at six UK hospitals. Patients aged 18 years or older with angina, stable coronary artery disease, ischaemia, and no further options for treatment were eligible. All patients completed a quantitative adenosine-stress perfusion cardiac magnetic resonance scan, symptom and quality-of-life questionnaires, and a treadmill exercise test before entering a 2-week symptom assessment phase, in which patients reported their angina symptoms using a smartphone application (ORBITA-app). Patients were randomly assigned (1:1) to receive either CSR or placebo. Both participants and investigators were masked to study assignment. After the CSR implantation or placebo procedure, patients entered a 6-month blinded follow-up phase in which they reported their daily symptoms in the ORBITA-app. At 6 months, all assessments were repeated. The primary outcome was myocardial blood flow in segments designated ischaemic at enrolment during the adenosine-stress perfusion cardiac magnetic resonance scan. The primary symptom outcome was the number of daily angina episodes. Analysis was done by intention-to-treat and followed Bayesian methodology. The study is registered with ClinicalTrials.gov, NCT04892537, and completed. FINDINGS: Between May 26, 2021, and June 28, 2023, 61 patients were enrolled, of whom 51 (44 [86%] male; seven [14%] female) were randomly assigned to either the CSR group (n=25) or the placebo group (n=26). Of these, 50 patients were included in the intention-to-treat analysis (24 in the CSR group and 26 in the placebo group). 454 (57%) of 800 imaged cardiac segments were ischaemic at enrolment, with a median stress myocardial blood flow of 1·08 mL/min per g (IQR 0·77-1·41). Myocardial blood flow in ischaemic segments did not improve with CSR compared with placebo (difference 0·06 mL/min per g [95% CrI -0·09 to 0·20]; Pr(Benefit)=78·8%). The number of daily angina episodes was reduced with CSR compared with placebo (OR 1·40 [95% CrI 1·08 to 1·83]; Pr(Benefit)=99·4%). There were two CSR embolisation events in the CSR group, and no acute coronary syndrome events or deaths in either group. INTERPRETATION: ORBITA-COSMIC found no evidence that the CSR improved transmural myocardial perfusion, but the CSR did improve angina compared with placebo. These findings provide evidence for the use of CSR as a further antianginal option for patients with stable coronary artery disease. FUNDING: Medical Research Council, Imperial College Healthcare Charity, National Institute for Health and Care Research Imperial Biomedical Research Centre, St Mary's Coronary Flow Trust, British Heart Foundation.


Subject(s)
Angina, Stable , Coronary Artery Disease , Coronary Sinus , Percutaneous Coronary Intervention , Humans , Male , Female , Coronary Artery Disease/therapy , Angina, Stable/drug therapy , Coronary Sinus/diagnostic imaging , Bayes Theorem , Treatment Outcome , Percutaneous Coronary Intervention/adverse effects , Double-Blind Method , Ischemia , Adenosine
14.
Syst Biol ; 73(2): 279-289, 2024 Jul 27.
Article in English | MEDLINE | ID: mdl-38157277

ABSTRACT

Different genomic regions may reflect conflicting phylogenetic topologies primarily due to incomplete lineage sorting and/or gene flow. Genomic data are necessary to reconstruct the true species tree and explore potential causes of phylogenetic conflict. Here, we investigate the phylogenetic relationships of 4 Emberiza species (Aves: Emberizidae) and discuss the potential causes of the observed mitochondrial non-monophyly of Emberiza godlewskii (Godlewski's bunting) using phylogenomic analyses based on whole genome resequencing data from 41 birds. Analyses based on both the whole mitochondrial genome and ~39 kilobases from the non-recombining W chromosome reveal sister relationships between each the northern and southern populations of E. godlewskii with E. cioides and E. cia, respectively. In contrast, the monophyly of E. godlewskii is reflected by the phylogenetic signal of autosomal and Z chromosomal sequence data as well as demographic inference analyses, which-in combination-support the following tree topology: ([{E. godlewskii, E. cia}, E. cioides], E. jankowskii). Using D-statistics, we detected multiple gene flow events among different lineages, indicating pervasive introgressive hybridization within this clade. Introgression from an unsampled lineage that is sister to E. cioides or introgression from an unsampled mitochondrial + W chromosomal lineage of E. cioides into northern E. godlewskii may explain the phylogenetic conflict between the species tree estimated from genome-wide data versus mtDNA/W tree topologies. These results underscore the importance of using genomic data for phylogenetic reconstruction and species delimitation.


Subject(s)
Passeriformes , Phylogeny , Animals , Passeriformes/genetics , Passeriformes/classification , Maternal Inheritance/genetics , Genome, Mitochondrial/genetics , Gene Flow
16.
Clin Infect Dis ; 78(5): 1204-1213, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38227643

ABSTRACT

BACKGROUND: Infection prevention (IP) measures are designed to mitigate the transmission of pathogens in healthcare. Using large-scale viral genomic and social network analyses, we determined if IP measures used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic were adequate in protecting healthcare workers (HCWs) and patients from acquiring SARS-CoV-2. METHODS: We performed retrospective cross-sectional analyses of viral genomics from all available SARS-CoV-2 viral samples collected at UC San Diego Health and social network analysis using the electronic medical record to derive temporospatial overlap of infections among related viromes and supplemented with contact tracing data. The outcome measure was any instance of healthcare transmission, defined as cases with closely related viral genomes and epidemiological connection within the healthcare setting during the infection window. Between November 2020 through January 2022, 12 933 viral genomes were obtained from 35 666 patients and HCWs. RESULTS: Among 5112 SARS-CoV-2 viral samples sequenced from the second and third waves of SARS-CoV-2 (pre-Omicron), 291 pairs were derived from persons with a plausible healthcare overlap. Of these, 34 pairs (12%) were phylogenetically linked: 19 attributable to household and 14 to healthcare transmission. During the Omicron wave, 2106 contact pairs among 7821 sequences resulted in 120 (6%) related pairs among 32 clusters, of which 10 were consistent with healthcare transmission. Transmission was more likely to occur in shared spaces in the older hospital compared with the newer hospital (2.54 vs 0.63 transmission events per 1000 admissions, P < .001). CONCLUSIONS: IP strategies were effective at identifying and preventing healthcare SARS-CoV-2 transmission.


Subject(s)
COVID-19 , Genome, Viral , Health Personnel , SARS-CoV-2 , Humans , COVID-19/transmission , COVID-19/epidemiology , COVID-19/virology , SARS-CoV-2/genetics , Retrospective Studies , Cross-Sectional Studies , Male , Female , Adult , Middle Aged , Aged , Social Network Analysis , Contact Tracing , Genomics , Young Adult , Adolescent , Child , Aged, 80 and over , Cross Infection/transmission , Cross Infection/virology , Cross Infection/epidemiology , Child, Preschool
17.
J Am Chem Soc ; 146(11): 7723-7733, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38451833

ABSTRACT

Gallium phosphide is an established photoelectrode material for H2 or O2 evolution from water, but particle-based GaP photocatalysts for H2 evolution are very rare. To understand the reasons, we investigated the photocatalytic H2 evolution reaction (HER) of suspended n-type GaP particles with iodide, sulfite, ferricyanide, ferrous ion, and hydrosulfide as sacrificial electron donors, and using Pt, RhyCr2-yO3, and Ni2P HER cocatalysts. A record apparent quantum efficiency of 14.8% at 525 nm was achieved after removing gallium and oxide charge trapping states from the GaP surface, adding a Ni2P cocatalyst to reduce the proton reduction overpotential, lowering the Schottky-barrier at the GaP-cocatalyst interface, adjusting the polarity of the depletion layer at the GaP-liquid interface, and optimizing the electrochemical potential of the electron donor. The work not only showcases the main factors that control charge separation in suspended photocatalysts, but it also explains why most known HER photocatalysts in the literature are based on n-type and not p-type semiconductors.

18.
Ann Surg ; 280(1): 144-149, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38501233

ABSTRACT

OBJECTIVE: To quantify health utilities of the Glasgow Outcome Scale-Extended (GOSE) states after actual traumatic brain injury (TBI). BACKGROUND: Recovery after TBI is measured using the GOSE, a validated clinical trial endpoint. A recent public survey quantified the health utilities of some GOSE states after hypothetical TBI as worse than death. However, no health utilities exist for disability after actual TBI. METHODS: This national computer-adaptive survey followed Enhancing the Quality and Transparency of Health Research-Checklist for Reporting Results of Internet E-Surveys guidelines and recruited adult TBI survivors (injury >1 year prior) through their available surrogates. Using a standard gamble approach in randomized order, participants gave preferences for post-TBI categorical health states ranging from GOSE 2 to GOSE 8. We calculated median (interquartile range) health utilities for each GOSE state, from -1 (worse than death) to 1 (full health), with 0 as reference (death, GOSE 1). RESULTS: Of 515 eligible, 298 surrogates (58%) consented and completed the scenarios on TBI survivors' behalf. TBI survivors had a current median GOSE 5 (3-7). GOSE 2, GOSE 3, and GOSE 4 were rated worse than death by 89%, 64%, and 38%, respectively. The relationship was nonlinear, and intervals were unequal between states, with a bimodal distribution for GOSE 4. CONCLUSIONS: In this index study of actual post-TBI disability, poor neurological outcomes represented by GOSE 2 to GOSE 4 were perceived as worse than death by at least one in 3 survivors. Similar to previously reported public perceptions after a hypothetical TBI, these long-term perceptions may inform earlier post-TBI shared decision-making, as well as help shape value-based research and quality of care. LEVEL OF EVIDENCE: Level II-economic and value-based evaluations.


Subject(s)
Brain Injuries, Traumatic , Glasgow Outcome Scale , Humans , Brain Injuries, Traumatic/psychology , Male , Female , Adult , Middle Aged , Functional Status , Survivors/psychology , Surveys and Questionnaires , Aged
19.
Hepatology ; 77(2): 466-475, 2023 02 01.
Article in English | MEDLINE | ID: mdl-35869810

ABSTRACT

BACKGROUND: Ascites is a definitive sign of decompensated liver cirrhosis driven by portal hypertension. Although transjugular intrahepatic portosystemic shunt insertion (TIPS) is indicated for therapy of recurrent and refractory ascites, there is no evidence-based recommendation for a specific target of portal hepatic pressure gradient (PPG) decrease. METHODS: In this single-center, retrospective trial, we investigated the decrease of PPG in 341 patients undergoing TIPS insertion for therapy of refractory or recurrent ascites until 2015. During each procedure, portal and inferior vena cava pressures were invasively measured and correlated with patients' outcome and ascites progression over time, according to the prespecified Noninvasive Evaluation Program for TIPS and Follow-Up Network protocol (NCT03628807). RESULTS: Patients without ascites at 6 weeks after TIPS had significantly greater PPG reduction immediately after TIPS, compared to the patients with refractory ascites (median reduction 65% vs. 55% of pre-TIPS PPG; p = 0.001). Survival was significantly better if ascites was controlled, compared to patients with need for paracentesis 6 weeks after TIPS (median survival: 185 vs. 41 weeks; HR 2.0 [1.3-2.9]; p < 0.001). Therefore, higher PPG reduction by TIPS ( p = 0.005) and lower PPG after TIPS ( p = 0.02) correlated with resolution of severe ascites 6 weeks after TIPS. Multivariable analyses demonstrated that higher Child-Pugh score before TIPS (OR 1.3 [1.0-1.7]; p = 0.03) and lower serum sodium levels (OR 0.9 [0.9-1.0]; p = 0.004) were independently associated with ascites persistence 6 weeks after TIPS, whereas PPG reduction (OR 0.98 [0.97-1.00]; p = 0.02) was associated with resolution of ascites 6 weeks after TIPS. CONCLUSION: Extent of PPG reduction and/or lowering of target PPG immediately after TIPS placement is associated with improved ascites control in the short term and with survival in the long term. A structured follow-up visit for patients should assess persistence of ascites at 6 weeks after TIPS.


Subject(s)
Portasystemic Shunt, Transjugular Intrahepatic , Humans , Ascites/etiology , Ascites/surgery , Liver Cirrhosis/complications , Liver Cirrhosis/surgery , Retrospective Studies , Treatment Outcome
20.
J Med Virol ; 96(8): e29822, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39056238

ABSTRACT

COVID-19 vaccine became available in Tanzania during the first wave of the Omicron variant. During that time community seroprevalence of SARS-CoV-2 was already at 50%-80%. To date, it remains largely unknown whether ongoing vaccination with the primary series vaccines has any meaningful immune-boosting effects against newer Omicron subvariants. Therefore, we tested cross-neutralizing capacity of antibodies elicited by infection, vaccination, or both against SARS-CoV-2 Omicron subvariants BA.1, and the newer subvariants BQ.1.1 and XBB.1.5. that were unexperienced by this population. Participants who were either SARS-CoV-2 infected-only (n = 28), infected vaccinated (n = 22), or vaccinated-only (n = 73) were recruited from Dar-es-Salaam, Tanzania, between April and December 2022. Plasma 50% neutralization titers (NT50) against SARS-CoV-2 wild-type strain and Omicron subvariants were quantified by a lentiviral-based pseudo-virus assay. Percentage of participants with neutralizing activity against WT and BA.1 was high (>85%) but was reduced against BQ.1.1 (64%-77%) and XBB.1.5 (35%-68%) subvariants. The low median cross-neutralization titer was slightly higher in the infected vaccinated group compared to vaccine-only group against BQ.1.1 (NT50 148 vs. 85, p = 0.032) and XBB.1.5 (NT50 85 vs. 37 p = 0.022) subvariants. In contrast, vaccine-boost among the infected vaccinated did not result to increased cross-neutralization compared to infected-only participants (BQ.1.1 [NT50 of 148 vs. 100, p = 0.501] and XBB.1.5 [NT50 86 vs. 45, p = 0.474]). We report severely attenuated neutralization titers against BQ.1.1 and XBB.1.5 subvariants among vaccinated participants, which marginally improved in the infected vaccinated participants. Our findings call for further studies to evaluate effectiveness of the primary series vaccines in preventing severe infection and mortality against the newer variants.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , COVID-19 , SARS-CoV-2 , Vaccination , Humans , Tanzania/epidemiology , COVID-19/prevention & control , COVID-19/immunology , COVID-19/epidemiology , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19 Vaccines/administration & dosage , Male , Female , SARS-CoV-2/immunology , Adult , Middle Aged , Young Adult , Neutralization Tests , Adolescent
SELECTION OF CITATIONS
SEARCH DETAIL