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New Defensive Measures for Blacklisted Jurisdictions: What impact will Luxembourg’s recent announcement have on Cayman-domiciled funds?

On 30 March, the Luxembourg Government published a new draft law (the Draft Law) which looks set to increase the Luxembourg tax burden for transactions realised with enterprises based in jurisdictions on the EU’s list of “non-cooperative...




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Bioenergy, the Ugly Duckling of Mexico’s Energy Transition

Rosa Manzano carefully arranges pieces of wood in a big mud igloo that, seven days after it is full, will produce charcoal of high caloric content. “Our forest also produces oak, which in the past was only sold as firewood and had little value. But with forest management and the work of women who have […]

The post Bioenergy, the Ugly Duckling of Mexico’s Energy Transition appeared first on Inter Press Service.




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Football to allow five substitutes during post-virus fixture backlog

Teams face likely fixture congestion in a packed calendar as they attempt to make up for lost time when play can resume




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Many policy differences to tackle in government talks

Fianna Fáil, Fine Gael and the Green Party are meeting in the Department of Agriculture to try to resolve their significant differences on housing, public transport and the environment, writes Sandra Hurley.




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Coronavirus: China’s medical supply boom, lockdown backlog sparked surprise April exports rise

A surprise jump in Chinese exports in April will be short-lived, analysts said, with the world’s second largest economy unable to stay sheltered from the demand shock to come from the global economic downturn.A 3.5 per cent rise in shipments last month caught economists by surprise and left them scrambling for explanations as the consensus forecast was for an 11 per cent contraction.The rise was, in part, due to factories coming back online in China in March and April to fulfil orders that had…




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Philippines move for firms catering to Chinese gamblers to reopen amid lockdown faces backlash

The Philippines’ decision to allow gaming firms to resume their operations ahead of other local businesses has been met with fierce criticism, but officials insist the move is necessary as the government needs the revenue to fund its response to the Covid-19 pandemic.Philippine offshore gaming operators (Pogos) – which cater to gamblers in China, where the activity is illegal – were ordered to close in March as part of lockdowns to curb the spread of Covid-19. They employ tens of thousands of…




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Hong Kong lunchtime protesters return after coronavirus social-distancing rules are eased but police quickly disperse group in mall with pepper spray

Police dispersed lunchtime protesters with pepper spray in an upscale Hong Kong shopping centre just 12 hours after the government relaxed some coronavirus social-distancing measures and allowed people to gather in groups of eight on Friday.Shortly after dozens of anti-government demonstrators began yelling slogans and belting out their anthem, officers entered the IFC Mall in Central to cordon off their protest site, forcing the Apple store to lower its shutters.Later, police used pepper spray…





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Prince Harry and wife Meghan blacklist British tabloids

Prince Harry and his wife Meghan have written to Britain's biggest tabloids, vowing never to work with them again.




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Meghan Markle and Prince Harry residing in actor Tyler Perry's mansion: report

Oprah Winfrey has reportedly arranged for the Duke and Duchess to move into Tyler Perry's mansion




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Prince Harry and Meghan Markle's exit to get turned into a movie

Prince Harry and Meghan Markle are now going to have a film based on their life as well




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Meghan Markle, Prince Harry's biographer dishes the details about explosive tell-all book

Meghan Markle, Prince Harry gave interviews for the book to the authors before they left UK




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PIC24FXXKMXXX/KLXXX Flash Programming Specification

PIC24FXXKMXXX/KLXXX Flash Programming Specification




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KLPGA Raises Purse for 1st Tour Championship Since COVID-19 Hit

The KLPGA Tour has raised the total purse for its first major championship of the season, which resumes next week after a break of several months due to the coronavirus epidemic.The KLPGA said Thursday that it decided to raise the prize money for the KLPGA Championship from W2.3 billion to W3 billio...




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Impact of govt relief fails to trickle down to grassroots level

Islamabad : It has been rather unfortunate that despite a huge relief package of Rs50 billion for Utility Stores Corporation and a cut in POL products by almost 31 rupees in a month by the federal government, its impact has not trickled down to the grassroots level, as the general public is still...




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Loan No. 3255-NEP: Kathmandu Valley Water Supply Improvement Project - Additional Financing [KUKL//DNI/W/02/21 B]




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Loan No. 3000-NEP: Kathmandu Valley Wastewater Management Project [KUKL-WW/IS-03]




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AI is helping tackle one of the biggest unsolved problems in maths

Machine-learning algorithms are being used to tackle the Birch and Swinnerton-Dyer conjecture, one of the fiendishly difficult Millennium Prize Problems




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TikTok: How did the video-sharing app get so big so quickly?

TikTok's rise has been meteoric. With more than 3 million people a day now downloading the app, its success is down to more than just luck




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The sparkling history of tonic, from medical miracle to G&T essential

The story of how gin and tonic came together fizzes with adventure, discovery, imperial ambition, biopiracy and a generous splash of fake news




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On this day: Born May 10, 1995: Missy Franklin, American swimmer

A "star in the making" were the prophetic words of an announcer who had just witnessed 16-year-old Missy Franklin slice up the competition at swimming's 2011 world championships.




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We must act quickly to avoid a pandemic-related mental health crisis

We are already seeing the pandemic's effects on mental health, and we need to act urgently to avoid a full-blown crisis, says Sam Howells  




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Why countries should start weekly covid-19 testing for key workers

Many countries are focusing coronavirus testing on people who have covid-19 symptoms. But regularly testing all essential workers would have more of an impact




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Air France-KLM and Rolls-Royce eye job cuts

Air France-KLM and jet engine maker Rolls-Royce are considering job cuts as lockdowns take a toll on first-quarter earnings. Francis Maguire reports.




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Cleaner Air Quickly Brings Big Health Benefits, Study Finds

Title: Cleaner Air Quickly Brings Big Health Benefits, Study Finds
Category: Health News
Created: 12/6/2019 12:00:00 AM
Last Editorial Review: 12/6/2019 12:00:00 AM




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Gastric Bypass May Improve Diabetes Quickly

Title: Gastric Bypass May Improve Diabetes Quickly
Category: Health News
Created: 4/28/2011 11:01:00 AM
Last Editorial Review: 4/28/2011 12:00:00 AM




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Kelly the Robot Helps Kids Tackle Autism

Title: Kelly the Robot Helps Kids Tackle Autism
Category: Health News
Created: 5/1/2013 12:36:00 PM
Last Editorial Review: 5/2/2013 12:00:00 AM




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Few Sickle Cell Patients Receiving Beneficial Drug, Study Finds

Title: Few Sickle Cell Patients Receiving Beneficial Drug, Study Finds
Category: Health News
Created: 4/28/2015 12:00:00 AM
Last Editorial Review: 4/29/2015 12:00:00 AM




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Put Car Seat on Your Summer-Travel Checklist

Title: Put Car Seat on Your Summer-Travel Checklist
Category: Health News
Created: 4/29/2015 12:00:00 AM
Last Editorial Review: 4/30/2015 12:00:00 AM




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'Freckle' Gene Might Make You Look Older

Title: 'Freckle' Gene Might Make You Look Older
Category: Health News
Created: 4/28/2016 12:00:00 AM
Last Editorial Review: 4/29/2016 12:00:00 AM




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Do Your Knees Crackle and Pop?

Title: Do Your Knees Crackle and Pop?
Category: Health News
Created: 5/5/2017 12:00:00 AM
Last Editorial Review: 5/5/2017 12:00:00 AM




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Necklace Spots A-Fib in Just Over 30 Seconds

Title: Necklace Spots A-Fib in Just Over 30 Seconds
Category: Health News
Created: 5/6/2020 12:00:00 AM
Last Editorial Review: 5/7/2020 12:00:00 AM




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Necklace Spots A-Fib in Just Over 30 Seconds

A necklace outfitted with a high-tech pendant may be able to screen for signs of an abnormal heart rhythm condition known as atrial fibrillation.




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Got Flu? Deal Quickly With Complications

Title: Got Flu? Deal Quickly With Complications
Category: Health News
Created: 2/2/2020 12:00:00 AM
Last Editorial Review: 2/3/2020 12:00:00 AM




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Emergence of a Plasmid-Encoded Resistance-Nodulation-Division Efflux Pump Conferring Resistance to Multiple Drugs, Including Tigecycline, in Klebsiella pneumoniae

ABSTRACT

Transporters belonging to the chromosomally encoded resistance-nodulation-division (RND) superfamily mediate multidrug resistance in Gram-negative bacteria. However, the cotransfer of large gene clusters encoding RND-type pumps from the chromosome to a plasmid appears infrequent, and no plasmid-mediated RND efflux pump gene cluster has yet been found to confer resistance to tigecycline. Here, we identified a novel RND efflux pump gene cluster, designated tmexCD1-toprJ1, on plasmids from five pandrug-resistant Klebsiella pneumoniae isolates of animal origin. TMexCD1-TOprJ1 increased (by 4- to 32-fold) the MICs of tetracyclines (including tigecycline and eravacycline), quinolones, cephalosporins, and aminoglycosides for K. pneumoniae, Escherichia coli, and Salmonella. TMexCD1-TOprJ1 is closely related (64.5% to 77.8% amino acid identity) to the MexCD-OprJ efflux pump encoded on the chromosome of Pseudomonas aeruginosa. In an IncFIA plasmid, pHNAH8I, the tmexCD1-toprJ1 gene cluster lies adjacent to two genes encoding site-specific integrases, which may have been responsible for its acquisition. Expression of TMexCD1-TOprJ1 in E. coli resulted in increased tigecycline efflux and in K. pneumoniae negated the efficacy of tigecycline in an in vivo infection model. Expression of TMexCD1-TOprJ1 reduced the growth of E. coli and Salmonella but not K. pneumoniae. tmexCD1-toprJ1-positive Enterobacteriaceae isolates were rare in humans (0.08%) but more common in chicken fecal (14.3%) and retail meat (3.4%) samples. Plasmid-borne tmexCD1-toprJ1-like gene clusters were identified in sequences in GenBank from Enterobacteriaceae and Pseudomonas strains from multiple continents. The possibility of further global dissemination of the tmexCD1-toprJ1 gene cluster and its analogues in Enterobacteriaceae via plasmids may be an important consideration for public health planning.

IMPORTANCE In an era of increasing concerns about antimicrobial resistance, tigecycline is likely to have a critically important role in the treatment of carbapenem-resistant Enterobacteriaceae, the most problematic pathogens in human clinical settings—especially carbapenem-resistant K. pneumoniae. Here, we identified a new plasmid-borne RND-type tigecycline resistance determinant, TMexCD1-TOprJ1, which is widespread among K. pneumoniae isolates from food animals. tmexCD1-toprJ1 appears to have originated from the chromosome of a Pseudomonas species and may have been transferred onto plasmids by adjacent site-specific integrases. Although tmexCD1-toprJ1 still appears to be rare in human clinical isolates, considering the transferability of the tmexCD1-toprJ1 gene cluster and the broad substrate spectrum of TMexCD1-TOprJ1, further dissemination of this mobile tigecycline resistance determinant is possible. Therefore, from a "One Health" perspective, measures are urgently needed to monitor and control its further spread. The current low prevalence in human clinical isolates provides a precious time window to design and implement measures to tackle this.




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Global Trends in Proteome Remodeling of the Outer Membrane Modulate Antimicrobial Permeability in Klebsiella pneumoniae

ABSTRACT

In Gram-negative bacteria, the permeability of the outer membrane governs rates of antibiotic uptake and thus the efficacy of antimicrobial treatment. Hydrophilic drugs like β-lactam antibiotics depend on diffusion through pore-forming outer membrane proteins to reach their intracellular targets. In this study, we investigated the distribution of porin genes in more than 2,700 Klebsiella isolates and found a widespread loss of OmpK35 functionality, particularly in those strains isolated from clinical environments. Using a defined set of outer-membrane-remodeled mutants, the major porin OmpK35 was shown to be largely responsible for β-lactam permeation. Sequence similarity network analysis characterized the porin protein subfamilies and led to discovery of a new porin family member, OmpK38. Structure-based comparisons of OmpK35, OmpK36, OmpK37, OmpK38, and PhoE showed near-identical pore frameworks but defining differences in the sequence characteristics of the extracellular loops. Antibiotic sensitivity profiles of isogenic Klebsiella pneumoniae strains, each expressing a different porin as its dominant pore, revealed striking differences in the antibiotic permeability characteristics of each channel in a physiological context. Since K. pneumoniae is a nosocomial pathogen with high rates of antimicrobial resistance and concurrent mortality, these experiments elucidate the role of porins in conferring specific drug-resistant phenotypes in a global context, informing future research to combat antimicrobial resistance in K. pneumoniae.

IMPORTANCE Klebsiella pneumoniae is a pathogen of humans with high rates of mortality and a recognized global rise in incidence of carbapenem-resistant K. pneumoniae (CRKP). The outer membrane of K. pneumoniae forms a permeability barrier that modulates the ability of antibiotics to reach their intracellular target. OmpK35, OmpK36, OmpK37, OmpK38, PhoE, and OmpK26 are porins in the outer membrane of K. pneumoniae, demonstrated here to have a causative relationship to drug resistance phenotypes in a physiological context. The data highlight that currently trialed combination treatments with a carbapenem and β-lactamase inhibitors could be effective on porin-deficient K. pneumoniae. Together with structural data, the results reveal the role of outer membrane proteome remodeling in antimicrobial resistance of K. pneumoniae and point to the role of extracellular loops, not channel parameters, in drug permeation. This significant finding warrants care in the development of phage therapies for K. pneumoniae infections, given the way porin expression will be modulated to confer phage-resistant—and collateral drug-resistant—phenotypes in K. pneumoniae.




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Seismic imaging of melanges; Pieniny Klippen Belt case study

The authors present results of the first high-resolution deep seismic reflection survey in the Pieniny Klippen Belt (PKB) in Poland. This survey sheds new light on the matter of olistostromes and the mélange character of the PKB. The sedimentary mass-transport deposits represented by olistoliths and olistostromes manifest themselves by different petrophysical parameters of rocks (velocity, density and resistivity) and seismic attributes. Seismic attributes are very effective in the interpretation of the geology of complex mélanges. The authors used selected attributes: low-pass filter, energy, energy gradient, dip-steered median filter, Prewitt filter, Laplacian edge enhancing filter and square root of the energy gradient. These attributes emphasize changes of the seismic image inside mélange zones. The distinguished olistoliths are now inside imbricated thrust structures and they are tectonically rearranged. Polygenetic mélanges in the PKB originated as a result of sedimentary and tectonic processes. The PKB in the investigated area forms several north-vergent thrust sheets belonging to the Złatne and Hulina nappes. Both nappes contain large chaotic, non-reflective olistoliths as well as the smaller mainly high-reflective olistoliths. Olistoliths are arranged parallel to the flysch layering and thrusts. The results presented confirm the postulated two olistostrome belts within the PKB structure.

Thematic collection: This article is part of the Polygenetic mélanges collection available at: https://www.lyellcollection.org/cc/polygenetic-melanges




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Genomic Investigation Reveals Contaminated Detergent as the Source of an Extended-Spectrum-{beta}-Lactamase-Producing Klebsiella michiganensis Outbreak in a Neonatal Unit [Bacteriology]

Klebsiella species are problematic pathogens in neonatal units and may cause outbreaks, for which the sources of transmission may be challenging to elucidate. We describe the use of whole-genome sequencing (WGS) to investigate environmental sources of transmission during an outbreak of extended-spectrum-β-lactamase (ESBL)-producing Klebsiella michiganensis colonizing neonates. Ceftriaxone-resistant Klebsiella spp. isolated from neonates (or their mothers) and the hospital environment were included. Short-read sequencing (Illumina) and long-read sequencing (MinION; Oxford Nanopore Technologies) were used to confirm species taxonomy, to identify antimicrobial resistance genes, and to determine phylogenetic relationships using single-nucleotide polymorphism profiling. A total of 21 organisms (10 patient-derived isolates and 11 environmental isolates) were sequenced. Standard laboratory methods identified the outbreak strain as an ESBL-producing Klebsiella oxytoca, but taxonomic assignment from WGS data suggested closer identity to Klebsiella michiganensis. Strains isolated from multiple detergent-dispensing bottles were either identical or closely related by single-nucleotide polymorphism comparison. Detergent bottles contaminated by K. michiganensis had been used for washing milk expression equipment. No new cases were identified once the detergent bottles were removed. Environmental reservoirs may be an important source in outbreaks of multidrug-resistant organisms. WGS, in conjunction with traditional epidemiological investigation, can be instrumental in revealing routes of transmission and guiding infection control responses.




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Fourier Transform Infrared Spectroscopy Is a New Option for Outbreak Investigation: a Retrospective Analysis of an Extended-Spectrum-Beta-Lactamase-Producing Klebsiella pneumoniae Outbreak in a Neonatal Intensive Care Unit [Epidemiology]

The IR Biotyper is a new automated typing system based on Fourier-transform infrared (FT-IR) spectroscopy that gives results within 4 h. We aimed (i) to use the IR Biotyper to retrospectively analyze an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) in a neonatal intensive care unit and to compare results to BOX-PCR and whole-genome sequencing (WGS) results as the gold standard and (ii) to assess how the cutoff values used to define clusters affect the discriminatory power of the IR Biotyper. The sample consisted of 18 isolates from 14 patients. Specimens were analyzed in the IR Biotyper using the default analysis settings, and spectra were analyzed using OPUS 7.5 software. The software contains a feature that automatically proposes a cutoff value to define clusters; the cutoff value defines up to which distance the spectra are considered to be in the same cluster. Based on FT-IR, the outbreak represented 1 dominant clone, 1 secondary clone, and several unrelated clones. FT-IR results, using the cutoff value generated by the accompanying software after 4 replicates, were concordant with WGS for all but 1 isolate. BOX-PCR was underdiscriminatory compared to the other two methods. Using the cutoff value generated after 12 replicates, the results of FT-IR and WGS were completely concordant. The IR Biotyper can achieve the same typeability and discriminatory power as genome-based methods. However, to attain this high performance requires either previous, strain-dependent knowledge about the optimal technical parameters to be used or validation by a second method.




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NO-Releasing Nanoparticles Ameliorate Detrusor Overactivity in Transgenic Sickle Cell Mice via Restored NO/ROCK Signaling [Cellular and Molecular]

Sickle cell disease (SCD) is associated with overactive bladder (OAB). Detrusor overactivity, a component of OAB, is present in an SCD mouse, but the molecular mechanisms for this condition are not well-defined. We hypothesize that nitric oxide (NO)/ ras homolog gene family (Rho) A/Rho-associated kinase (ROCK) dysregulation is a mechanism for detrusor overactivity and that NO-releasing nanoparticles (NO-nps), a novel NO delivery system, may serve to treat this condition. Male adult SCD transgenic, combined endothelial NO synthases (eNOSs) and neuronal NOS (nNOS) gene-deficient (dNOS–/–), and wild-type (WT) mice were used. Empty nanoparticle or NO-np was injected into the bladder, followed by cystometric studies. The expression levels of phosphorylated eNOS (Ser-1177), protein kinase B (Akt) (Ser-473), nNOS (Ser-1412), and myosin phosphatase target subunit 1 (MYPT1) (Thr-696) were assessed in the bladder. SCD and dNOS–/– mice had a greater (P < 0.05) number of voiding and nonvoiding contractions compared with WT mice, and they were normalized by NO-np treatment. eNOS (Ser-1177) and AKT (Ser-473) phosphorylation were decreased (P < 0.05) in the bladder of SCD compared with WT mice and reversed by NO-np. Phosphorylated MYPT1, a marker of the RhoA/ROCK pathway, was increased (P < 0.05) in the bladder of SCD mice compared with WT and reversed by NO-np. nNOS phosphorylation on positive (Ser-1412) regulatory site was decreased (P < 0.05) in the bladder of SCD mice compared with WT and was not affected by NO-np. NO-nps did not affect any of the measured parameters in WT mice. In conclusion, dysregulation of NO and RhoA/ROCK pathways is associated with detrusor overactivity in SCD mice; NO-np reverses these molecular derangements in the bladder and decreases detrusor overactivity.

SIGNIFICANCE STATEMENT

Voiding abnormalities commonly affect patients with sickle cell disease (SCD) but are problematic to treat. Clarification of the science for this condition in an animal model of SCD may lead to improved interventions for it. Our findings suggest that novel topical delivery of a vasorelaxant agent nitric oxide into the bladder of these mice corrects overactive bladder by improving deranged bladder physiology regulatory signaling.




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The unknown planktonic foraminiferal pioneer Henry A. Buckley and his collection at The Natural History Museum, London

The Henry Buckley Collection of Planktonic Foraminifera at the Natural History Museum in London (NHMUK) consists of 1665 single-taxon slides housing 23 897 individuals from 203 sites in all the major ocean basins, as well as a vast research library of Scanning Electron Microscope (SEM) photomicrographs. Buckley picked the material from the NHMUK Ocean-Bottom Deposit Collection and also from fresh tow samples. However, his collection remains largely unused as he was discouraged by his managers in the Mineralogy Department from working on or publicizing the collection. Nevertheless, Buckley published pioneering papers on isotopic interpretation of oceanographic and climatic change and was one of the first workers to investigate foraminiferal wall structure using the SEM technique. Details of the collection and images of each slide are available via the NHMUK Data Portal (http://dx.doi.org/10.5519/0035055). The Buckley Collection and its associated Ocean-Bottom Deposit Collection have great potential for taxon-specific studies as well as geochemical work, and both collections are available on request.




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Extensive multilineage analysis in patients with mixed chimerism after allogeneic transplantation for sickle cell disease: insight into hematopoiesis and engraftment thresholds for gene therapy

Although studies of mixed chimerism following hematopoietic stem cell transplantation in patients with sickle cell disease (SCD) may provide insights into the engraftment needed to correct the disease and into immunological reconstitution, an extensive multilineage analysis is lacking. We analyzed chimerism simultaneously in peripheral erythroid and granulomonocytic precursors/progenitors, highly purified B and T lymphocytes, monocytes, granulocytes and red blood cells (RBC). Thirty-four patients with mixed chimerism and ≥12 months of follow-up were included. A selective advantage of donor RBC and their progenitors/precursors led to full chimerism in mature RBC (despite partial engraftment of other lineages), and resulted in the clinical control of the disease. Six patients with donor chimerism <50% had hemolysis (reticulocytosis) and higher HbS than their donor. Four of them had donor chimerism <30%, including a patient with AA donor (hemoglobin >10 g/dL) and three with AS donors (hemoglobin <10 g/dL). However, only one vaso-occlusive crisis occurred with 68.7% HbS. Except in the patients with the lowest chimerism, the donor engraftment was lower for T cells than for the other lineages. In a context of mixed chimerism after hematopoietic stem cell transplantation for SCD, myeloid (rather than T cell) engraftment was the key efficacy criterion. Results show that myeloid chimerism as low as 30% was sufficient to prevent a vaso-occlusive crisis in transplants from an AA donor but not constantly from an AS donor. However, the correction of hemolysis requires higher donor chimerism levels (i.e. ≥50%) in both AA and AS recipients. In the future, this group of patients may need a different therapeutic approach.




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Fitter, Better, Sooner: helping your patients in general practice recover more quickly from surgery




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An alternative COVID-19 checklist




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Comparison of Commensal and Clinical Isolates for Diversity of Plasmids in Escherichia coli and Klebsiella pneumoniae [Epidemiology and Surveillance]

In this study, the plasmid content of clinical and commensal strains was analyzed and compared. The replicon profile was similar in both populations, except for L, M, A/C, and N (detected only in clinical strains) and HI1 (only in commensal strains). Although I1 and F were the most frequent replicons, only IncI1, sequence type 12 (ST12) was associated with blaCMY-2 in both populations. In contrast, the widespread resistant IncF plasmids were not linked to a single epidemic plasmid.




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Molecular and Clinical Characterization of Multidrug-Resistant and Hypervirulent Klebsiella pneumoniae Strains from Liver Abscess in Taiwan [Epidemiology and Surveillance]

Hypervirulent Klebsiella pneumoniae strains are the major cause of liver abscesses throughout East Asia, and these strains are usually antibiotic susceptible. Recently, multidrug-resistant and hypervirulent (MDR-HV) K. pneumoniae strains have emerged due to hypervirulent strains acquiring antimicrobial resistance determinants or the transfer of a virulence plasmid into a classic MDR strain. In this study, we characterized the clinical and microbiological properties of K. pneumoniae liver abscess (KPLA) caused by MDR-HV strains in Taiwan. Patients with community onset KPLA were retrospectively identified at Taipei Veterans General Hospital during January 2013 to May 2018. Antimicrobial resistance mechanisms, capsular types, and sequence types were determined. MDR-HV strains and their parental antimicrobial-susceptible strains further underwent whole-genome sequencing (WGS) and in vivo mice lethality tests. Thirteen MDR-HV strains were identified from a total of 218 KPLA episodes. MDR-HV strains resulted in similar outcomes to antimicrobial-susceptible strains. All MDR-HV strains were traditional hypervirulent clones carrying virulence capsular types. The major resistance mechanisms were the overexpression of efflux pumps and/or the acquisition of ESBL or AmpC β-lactamase genes. WGS revealed that two hypervirulent strains had evolved to an MDR phenotype due to mutation in the ramR gene and the acquisition of an SHV-12-bearing plasmid, respectively. Both these MDR-HV strains retained high virulence compared to their parental strains. The spread of MDR-HV K. pneumoniae strains in the community raises significant public concerns, and measures should be taken to prevent the further acquisition of carbapenemase and other resistance genes among these strains in order to avoid the occurrence of untreatable KPLA.




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ISEcp1-Mediated Transposition Leads to Fosfomycin and Broad-Spectrum Cephalosporin Resistance in Klebsiella pneumoniae [Mechanisms of Resistance]

A fosfomycin-resistant and carbapenemase (OXA-48)-producing Klebsiella pneumoniae isolate was recovered, and whole-genome sequencing revealed ISEcp1-blaCTX-M-14b tandemly inserted upstream of the chromosomally encoded lysR-fosA locus. Quantitative evaluation of the expression of lysR and fosA genes showed that this insertion brought a strong hybrid promoter leading to overexpression of the fosA gene, resulting in fosfomycin resistance. This work showed the concomitant acquisition of resistance to broad-spectrum cephalosporins and fosfomycin due to a single genetic event.




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ARGONAUT II Study of the In Vitro Activity of Plazomicin against Carbapenemase-Producing Klebsiella pneumoniae [Mechanisms of Resistance]

Plazomicin was tested against 697 recently acquired carbapenem-resistant Klebsiella pneumoniae isolates from the Great Lakes region of the United States. Plazomicin MIC50 and MIC90 values were 0.25 and 1 mg/liter, respectively; 680 isolates (97.6%) were susceptible (MICs of ≤2 mg/liter), 9 (1.3%) intermediate (MICs of 4 mg/liter), and 8 (1.1%) resistant (MICs of >32 mg/liter). Resistance was associated with rmtF-, rmtB-, or armA-encoded 16S rRNA methyltransferases in all except 1 isolate.




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E. coli DNA Polymerase I and the Klenow Fragment

Escherichia coli DNA Pol I can carry out three enzymatic reactions: It possesses 5' -> 3' DNA polymerase activity and 3' -> 5' and 5' -> 3' exonuclease activity. Pol I can be cleaved by mild treatment with subtilisin into two fragments; the larger fragment is known as the Klenow fragment. The Klenow fragment retains the polymerizing activity and the 3' -> 5' exonuclease of the holo-enzyme but lacks its powerful 5' -> 3' exonuclease activity. These enzymes and their applications in molecular cloning are introduced here.




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Labeling 3' Termini of Double-Stranded DNA Using the Klenow Fragment of E. coli DNA Polymerase I

The Klenow fragment, which retains the template-dependent deoxynucleotide polymerizing activity and the 3' -> 5' exonuclease of the holo-enzyme but lacks its powerful 5' -> 3' exonuclease activity, is used to fill recessed 3' termini of dsDNA. In this protocol, fragments suitable as templates for the end-filling reaction are produced by digestion of DNA with an appropriate restriction enzyme. The Klenow enzyme is then used to catalyze the attachment of dNTPs to the recessed 3'-hydroxyl groups.