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Observing Asthma Awareness Month, EPA Honors Leading Community Asthma Care Programs in Colorado and Texas

WASHINGTON (April 30, 2020) — Tomorrow, in celebration of Asthma Awareness Month, the Environmental Protection Agency (EPA) will honor two outstanding asthma care programs, the Children’s Hospital Colorado Breathing Institute in Aurora, Colorado and the Univers




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EPA Honors University of Texas Health Science Center at Tyler for Outstanding Community Asthma Care Program

DALLAS – (May 1, 2020) In celebration of Asthma Awareness Month, the U.S.




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EPA Approves New York and New Jersey Clean Air Plans

NEW YORK - In conjunction with Air Quality Awareness Week, the U.S. Environmental Protection Agency (EPA) Region 2 recently approved several updates to New York and New Jersey’s clean air plans.




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Reinvent, smartly: A Gates Foundation-led rethink of New York public schools has promise and risks

A state full of parents who, having been suddenly forced to help homeschool youngsters, have by the millions grown more appreciative of the work of professional teachers in actual classrooms, had reason to worry when they heard how Gov. Cuomo trotted out plans for a Gates Foundation reinvention of public education statewide.




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A life-or-death moment for cities: New York and other metropolises must protect themselves from pandemics or our future will be far less urban

COVID-19 has killed at least 19,000 New Yorkers and dealt a body blow with lasting consequences to the city. Two paths lie ahead. If pandemics become common, then not only New York City but all of America’s service-based economy faces a bleak future. If this terrible plague is a unique event, then things will eventually get almost back to normal. To save both the nation’s biggest and most productive metropolis and tens of millions of service jobs across the county, we must invest enormously to prevent future pandemics.




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Georgia AG to probe local authorities’ response to Ahmaud Arbery killing

The Georgia attorney general has promised his office will investigate the handling of the death of Ahmaud Arbery, the black 25-year-old man shot to death by two white men who escaped charges for more than two months.




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Georgia AG to probe local authorities’ response to Ahmaud Arbery killing

The Georgia attorney general has promised his office will investigate the handling of the death of Ahmaud Arbery, the black 25-year-old man shot to death by two white men who escaped charges for more than two months.




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Purdue promotes Norbert Elliott to track and field and cross country coach

Norbert Elliott, who served as associate track and field and cross country coach, succeeds Lonnie Greene as head coach.

      




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Purdue basketball recruiting target Brandon Newman going extra mile for improvement

Brandon Newman's stock rose considerably in the past six months. The 2019 guard from Valparaiso will play at Montverde (Florida) Academy as a senior.

      




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Where locals land on new basketball prospect rankings for 2019 and 2020

A look at where locals land on new national lists

       




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Raw video: Protestors gather at West 62nd Street and Michigan Road on Saturday

About 50 people gathered Saturday afternoon at West 62nd Street and Michigan Road to protest the fatal police shooting of Dreasjon "Sean" Reed.

       




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Raw video shows officer using pepper balls while making an arrest during a protest

Indianapolis police arrested a man on Saturday near the location of the fatal police shooting of Dreasjon "Sean" Reed days earlier.

       




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Protests continue at 62nd Street and Michigan Road following death of Dreasjon Reed

Protests continued near 62nd Street and Michigan Road in Indianapolis on May 9, 2020, following the May 6 police shooting death of Dreasjon Reed.

       




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Demonstrators describe arrest and pepper ball deployment during protest

Demonstrators describe an arrest and pepper ball use by IMPD during a protest over the death of Dreasjon Reed near 62nd Street and Michigan Road.

       




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Police use pepper balls while arresting man during protest of fatal police shooting

Indianapolis police arrested a man on Saturday near the location of the fatal police shooting of Dreasjon "Sean" Reed days earlier.

       




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Protests continue at 62nd Street and Michigan Road following death of Dreasjon Reed

Protests continued near 62nd Street and Michigan Road in Indianapolis on May 9, 2020, following the May 6 police shooting death of Dreasjon Reed.

       




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C Is Now the Most Popular Programming Language, Claims TIOBE

Charlotte Web writes: Since 2001 the TIOBE Index has been ranking top results for the search query +"<language> programming" on the top 25 search engines. "This month, C moved up past Java and entered the number one position," reports JAXenter. "There's a new number one. (Or, should we say an old number one?)" "Java and C were already very close in April, but this month C surpasses Java again," explains Paul Jansen CEO TIOBE Software. He also points out that the last time C was number one was back in 2015, suggesting that today embedded software languages like C and C++ "are gaining popularity because these are used in software for medical devices." "On another note, it is also worth mentioning that Rust is really getting close to the top 20 now (from #27 to #21 within one month)." "Perl, on the other hand, might be on its way off of the charts," argues JAXenter, "if it continues its downward trend. This month it saw a rate of change of -0.51%. It is currently number 18 on the list, but in May 2019 it was number 13." Python also passed C++ to take the #3 spot, while C# overtook Visual Basic for the #5 spot. ("Classic Visual Basic" also lost the #16 spot to PL/SQL). Even PHP rose a notch, pushing past SQL to take the #8 spot, and Scratch also moved up one, overtaking Objective C for the #19 position.

Read more of this story at Slashdot.




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Demonstrations at Co-op facilities affecting Sask. producers: APAS

The Agricultural Producers Association of Saskatchewan (APAS) is the latest organization to weigh in on the Co-op Refinery labour dispute, saying demonstrations at Co-op facilities could negatively affect farmer’s seeding.





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Ontario provincial parks will reopen but for day-use only

Ontario's provincial parks and conservation areas will reopen this week but campgrounds and beaches will continue to be off-limits for now.




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Pro14 season resumption planned for late August

Plans are being considered to resume a curtailed Pro14 season on 22 August following the coronavirus crisis.




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Demonstrations in Thailand? No Problem, Travelers Say.

Filed under: ,

Shutterstock
The political protests currently taking place in parts of Bangkok don't seem to be affecting travel to and within Thailand. And that should be no surprise. Despite events -- a coup, floods and protests that closed an airport among them -- that have rocked the country in recent years, travelers remain unfazed about visiting Thailand.

Quartz reports:

Not only are tourists still coming, but they've been arriving in increasing numbers in recent years, according to government data.

The story adds:

Continue reading Demonstrations in Thailand? No Problem, Travelers Say.

Demonstrations in Thailand? No Problem, Travelers Say. originally appeared on Gadling on Mon, 02 Dec 2013 11:26:00 EST. Please see our terms for use of feeds.

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Another Boeing 787 Dreamliner Has a Battery Problem

Filed under: , , ,

Getty Images
Japan Airlines grounded a Boeing 787 Dreamliner aircraft today "after detecting smoke or gases that may have come from faults with the main battery," according to the BBC.

Last year, all 787s were grounded for three months, CBS reports, after a "fire in a lithium ion battery aboard a Japan Airlines 787 parked at Boston's Logan International Airport. That was followed nine days later by another battery incident that forced an emergency landing in Japan by an All Nippon Airways 787.

Continue reading Another Boeing 787 Dreamliner Has a Battery Problem

Another Boeing 787 Dreamliner Has a Battery Problem originally appeared on Gadling on Tue, 14 Jan 2014 14:57:00 EST. Please see our terms for use of feeds.

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News24.com | Covid-19: Big profits for the cigarette 'black market' in KZN

The ban on cigarette and alcohol sales during the lockdown has created an underground market of rampant deals all over Pietermaritzburg.




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Protesters want Alberta to reopen economy more quickly

Dozens of protesters descended on the legislature Saturday afternoon, calling for a quicker reopening of the Alberta economy.




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Okotoks, Alta. families provided food donations through Dawgs' Food Drive

Residents in Okotoks, Alta. were about to help support those less fortunate in their community by donating non-perishable food items in a drive hosted by a local baseball club.





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Provinces begin to address backlog of surgeries in wake of COVID-19

Hospitals in British Columbia and Ontario are beginning to address major backlogs in surgeries after the COVID-19 pandemic forced thousands of cancellations that could take well over a year to address.




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Professor Who Mocked Barron Trump During Senate Hearings Gets Censorship Position at Facebook

The following article, Professor Who Mocked Barron Trump During Senate Hearings Gets Censorship Position at Facebook, was first published on 100PercentFedUp.com.

Facebook just announced a 20 person board of oversight that will assist with content moderation. One of the people selected for the board, a professor at Stanford Law School, was announced as a member of the board and is raising eyebrows because of her snarky comment about Barron Trump during Senate Impeachment Hearings. Pamela Karlan, […]

Continue reading: Professor Who Mocked Barron Trump During Senate Hearings Gets Censorship Position at Facebook ...




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Rep. Ilhan Omar Asks For Contributions To Her Campaign To Help MN Food Bank…Food Bank Director Says Omar Has Nothing To Do With Project: “I have no idea where this money is going”

The following article, Rep. Ilhan Omar Asks For Contributions To Her Campaign To Help MN Food Bank…Food Bank Director Says Omar Has Nothing To Do With Project: “I have no idea where this money is going”, was first published on 100PercentFedUp.com.

Ilhan Omar is a lot of things. First, and foremost, she’s deceitful. David Steinberg of PJ Media was one of the first investigative journalists to break the story about the anti-Semitic, freshman lawmaker’s marriage to her immigrant brother while she was still married to her first husband, who she has since divorced after having an […]

Continue reading: Rep. Ilhan Omar Asks For Contributions To Her Campaign To Help MN Food Bank…Food Bank Director Says Omar Has Nothing To Do With Project: “I have no idea where this money is going” ...




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Protesters demand end to Manitoba's COVID-19 lockdown measures

A crowd descended on the Manitoba Legislature Building Saturday afternoon, demanding an end to the COVID-19 quarantine.




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Nigeria’s Priorities for Progress: Imperatives for Stability and Inclusive Growth

Research Event

24 July 2014 - 2:30pm to 3:30pm

Chatham House, London

Event participants

Dr Doyin Okupe, Senior Special Assistant on Public Affairs to the President of Nigeria 

Nigeria’s prospects, with its rise to international prominence as Africa’s largest economy, are tempered by the many development and security challenges the country faces. While essential reforms in the power and agriculture sectors are underway, such efforts are balanced against the Boko Haram insurgency in the northeast, significant concerns around youth unemployment, and an increasingly contentious political environment in the run-up to the February 2015 elections. 

Dr Doyin Okupe, Senior Special Assistant to President Goodluck Jonathan, will discuss what steps the presidency is taking to address the country’s most urgent challenges, and how the political environment can be managed to overcome tensions that may impede progress.

Department/project

Christopher Vandome

Research Fellow, Africa Programme
+44 (0) 20 7314 3669




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Social Network Creation: Pros and Cons




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PostAffiliatePro - Start Your Own Affiliate Program (Huge Discount)




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Get Your Automated Software solution| Custom Programming service.




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Dewbola Web Directory - Fast Approval




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Recommend a Best | Highest Affiliate Program that really pay?!!!




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Nepal protests new Indian road through disputed territory

Nepal protested India's inauguration of a new road to China that passes through territory claimed by Kathmandu on Saturday, with police arresting dozens demonstrating close to India's embassy. Indian defence minister Rajnath Singh on Friday inaugurated via video link the 80-kilometre (50 miles) long road from Ghatiabagarh in northern Uttarakhand state to the Lipu Lekh pass high in the Himalaya. The pass is claimed by Nepal based on an 1816 treaty that defines its western border with India.





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‘Not a Bonafide Counterintelligence Investigation’: Barr Slams Comey’s Handling of Flynn Probe

Attorney General Bill Barr explained that the FBI did not conduct “a bonafide counterintelligence investigation” in the case that led former Trump national security adviser Michael Flynn to plead guilty to federal investigators in 2017.Barr, speaking in an exclusive interview with CBS News after the Justice Department dropped its case against Flynn on Thursday, said that his review of the case found Bureau investigators laid “a perjury trap” for Flynn in a January 2017 White House interview.“They didn’t warn him, the way that would usually be required by the Department, they bypassed the Justice Department, they bypassed the protocols at the White House, and so forth,” Barr stated. “These were things that persuaded me that there was not a legitimate counterintelligence investigation.”Former FBI director James Comey admitted in a December 2018 interview that he “sent” the agents to interview Flynn, adding that it was “something I probably wouldn’t have done or maybe gotten away with in a more organized administration.”In its Thursday court filing, the Justice Department explained that it was “not persuaded” that Flynn’s interview, which led to his guilty plea for lying to FBI agents Peter Strzok and Joe Pientka, had proper predication and was materially relevant.Comey tweeted his disappointment, following the decision, saying "the DOJ has lost its way."> The DOJ has lost its way. But, career people: please stay because America needs you. The country is hungry for honest, competent leadership.> > -- James Comey (@Comey) May 7, 2020Barr pointed to recently-released information that showed the FBI moved to close its surveillance of Flynn after finding “no derogatory information” about the retired general’s contacts with Russians, only for Strzok to keep the case open, leading to the eventual interview.“They were closing the investigation, in December [2016], they started that process and on January 4, they were closing it. When they heard about the phone call, which the FBI had the transcripts to — there was no question as to what was discussed, the FBI knew exactly what was discussed — and General Flynn, being the former director of the DIA, said to them, ‘you listen to everything, you know what was said,’” Barr explained.“So there’s no mystery about the call, but they initially tried some theories of how could open another investigation, which didn’t fly, and then they found out that they had not technically closed the earlier investigation, and they kept it open for the expressed purpose of trying to catch — lay a perjury trap — for General Flynn,” he added. A different filing released last week showed handwritten notes from an FBI official that questioned if the goal of Flynn’s White House interview was “to get him to lie, so we can prosecute him or get him fired.”Barr also did not comment on whether those that sought to entrap Flynn would face criminal charges, pointing to U.S. Attorney John Durham’s probe into the origins of the Trump-Russia investigation and saying his team was “in the middle” of “looking at the whole pattern of conduct.”“I’m going to wait until all the evidence is [in], and I get their recommendations as to what they found and how serious it is. But, if we were to find wrongdoing, in the sense of any criminal act, obviously we would follow through on that,” Barr said. “But again, just because something may even stink to high heaven, and appear to everyone to be bad, we still have to apply the right standard and be convinced that there is a violation of a criminal statute and that we can prove it beyond a reasonable doubt. The same standard applies to everybody.”





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Structures of the MHC-I molecule BF2*1501 disclose the preferred presentation of an H5N1 virus-derived epitope [Protein Structure and Folding]

Lethal infections by strains of the highly-pathogenic avian influenza virus (HPAIV) H5N1 pose serious threats to both the poultry industry and public health worldwide. A lack of confirmed HPAIV epitopes recognized by cytotoxic T lymphocytes (CTLs) has hindered the utilization of CD8+ T-cell–mediated immunity and has precluded the development of effectively diversified epitope-based vaccination approaches. In particular, an HPAIV H5N1 CTL-recognized epitope based on the peptide MHC-I–β2m (pMHC-I) complex has not yet been designed. Here, screening a collection of selected peptides of several HPAIV strains against a specific pathogen-free pMHC-I (pBF2*1501), we identified a highly-conserved HPAIV H5N1 CTL epitope, named HPAIV–PA123–130. We determined the structure of the BF2*1501–PA123–130 complex at 2.1 Å resolution to elucidate the molecular mechanisms of a preferential presentation of the highly-conserved PA123–130 epitope in the chicken B15 lineage. Conformational characteristics of the PA123–130 epitope with a protruding Tyr-7 residue indicated that this epitope has great potential to be recognized by specific TCRs. Moreover, significantly increased numbers of CD8+ T cells specific for the HPAIV–PA123–130 epitope in peptide-immunized chickens indicated that a repertoire of CD8+ T cells can specifically respond to this epitope. We anticipate that the identification and structural characterization of the PA123–130 epitope reported here could enable further studies of CTL immunity against HPAIV H5N1. Such studies may aid in the development of vaccine development strategies using well-conserved internal viral antigens in chickens.




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Structural insight into the recognition of pathogen-derived phosphoglycolipids by C-type lectin receptor DCAR [Protein Structure and Folding]

The C-type lectin receptors (CLRs) form a family of pattern recognition receptors that recognize numerous pathogens, such as bacteria and fungi, and trigger innate immune responses. The extracellular carbohydrate-recognition domain (CRD) of CLRs forms a globular structure that can coordinate a Ca2+ ion, allowing receptor interactions with sugar-containing ligands. Although well-conserved, the CRD fold can also display differences that directly affect the specificity of the receptors for their ligands. Here, we report crystal structures at 1.8–2.3 Å resolutions of the CRD of murine dendritic cell-immunoactivating receptor (DCAR, or Clec4b1), the CLR that binds phosphoglycolipids such as acylated phosphatidyl-myo-inositol mannosides (AcPIMs) of mycobacteria. Using mutagenesis analysis, we identified critical residues, Ala136 and Gln198, on the surface surrounding the ligand-binding site of DCAR, as well as an atypical Ca2+-binding motif (Glu-Pro-Ser/EPS168–170). By chemically synthesizing a water-soluble ligand analog, inositol-monophosphate dimannose (IPM2), we confirmed the direct interaction of DCAR with the polar moiety of AcPIMs by biolayer interferometry and co-crystallization approaches. We also observed a hydrophobic groove extending from the ligand-binding site that is in a suitable position to interact with the lipid portion of whole AcPIMs. These results suggest that the hydroxyl group-binding ability and hydrophobic groove of DCAR mediate its specific binding to pathogen-derived phosphoglycolipids such as mycobacterial AcPIMs.




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Polarization of protease-activated receptor 2 (PAR-2) signaling is altered during airway epithelial remodeling and deciliation [Immunology]

Protease-activated receptor 2 (PAR-2) is activated by secreted proteases from immune cells or fungi. PAR-2 is normally expressed basolaterally in differentiated nasal ciliated cells. We hypothesized that epithelial remodeling during diseases characterized by cilial loss and squamous metaplasia may alter PAR-2 polarization. Here, using a fluorescent arrestin assay, we confirmed that the common fungal airway pathogen Aspergillus fumigatus activates heterologously-expressed PAR-2. Endogenous PAR-2 activation in submerged airway RPMI 2650 or NCI–H520 squamous cells increased intracellular calcium levels and granulocyte macrophage–colony-stimulating factor, tumor necrosis factor α, and interleukin (IL)-6 secretion. RPMI 2650 cells cultured at an air–liquid interface (ALI) responded to apically or basolaterally applied PAR-2 agonists. However, well-differentiated primary nasal epithelial ALIs responded only to basolateral PAR-2 stimulation, indicated by calcium elevation, increased cilia beat frequency, and increased fluid and cytokine secretion. We exposed primary cells to disease-related modifiers that alter epithelial morphology, including IL-13, cigarette smoke condensate, and retinoic acid deficiency, at concentrations and times that altered epithelial morphology without causing breakdown of the epithelial barrier to model early disease states. These altered primary cultures responded to both apical and basolateral PAR-2 stimulation. Imaging nasal polyps and control middle turbinate explants, we found that nasal polyps, but not turbinates, exhibit apical calcium responses to PAR-2 stimulation. However, isolated ciliated cells from both polyps and turbinates maintained basolateral PAR-2 polarization, suggesting that the calcium responses originated from nonciliated cells. Altered PAR-2 polarization in disease-remodeled epithelia may enhance apical responses and increase sensitivity to inhaled proteases.




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Cell-specific expression of the transcriptional regulator RHAMM provides a timing mechanism that controls appropriate wound re-epithelialization [Glycobiology and Extracellular Matrices]

Prevention of aberrant cutaneous wound repair and appropriate regeneration of an intact and functional integument require the coordinated timing of fibroblast and keratinocyte migration. Here, we identified a mechanism whereby opposing cell-specific motogenic functions of a multifunctional intracellular and extracellular protein, the receptor for hyaluronan-mediated motility (RHAMM), coordinates fibroblast and keratinocyte migration speed and ensures appropriate timing of excisional wound closure. We found that, unlike in WT mice, in Rhamm-null mice, keratinocyte migration initiates prematurely in the excisional wounds, resulting in wounds that have re-surfaced before the formation of normal granulation tissue, leading to a defective epidermal architecture. We also noted aberrant keratinocyte and fibroblast migration in the Rhamm-null mice, indicating that RHAMM suppresses keratinocyte motility but increases fibroblast motility. This cell context–dependent effect resulted from cell-specific regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) activation and expression of a RHAMM target gene encoding matrix metalloprotease 9 (MMP-9). In fibroblasts, RHAMM promoted ERK1/2 activation and MMP-9 expression, whereas in keratinocytes, RHAMM suppressed these activities. In keratinocytes, loss of RHAMM function or expression promoted epidermal growth factor receptor–regulated MMP-9 expression via ERK1/2, which resulted in cleavage of the ectodomain of the RHAMM partner protein CD44 and thereby increased keratinocyte motility. These results identify RHAMM as a key factor that integrates the timing of wound repair by controlling cell migration.




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An enzyme-based protocol for cell-free synthesis of nature-identical capsular oligosaccharides from Actinobacillus pleuropneumoniae serotype 1 [Enzymology]

Actinobacillus pleuropneumoniae (App) is the etiological agent of acute porcine pneumonia and responsible for severe economic losses worldwide. The capsule polymer of App serotype 1 (App1) consists of [4)-GlcNAc-β(1,6)-Gal-α-1-(PO4-] repeating units that are O-acetylated at O-6 of the GlcNAc. It is a major virulence factor and was used in previous studies in the successful generation of an experimental glycoconjugate vaccine. However, the application of glycoconjugate vaccines in the animal health sector is limited, presumably because of the high costs associated with harvesting the polymer from pathogen culture. Consequently, here we exploited the capsule polymerase Cps1B of App1 as an in vitro synthesis tool and an alternative for capsule polymer provision. Cps1B consists of two catalytic domains, as well as a domain rich in tetratricopeptide repeats (TPRs). We compared the elongation mechanism of Cps1B with that of a ΔTPR truncation (Cps1B-ΔTPR). Interestingly, the product profiles displayed by Cps1B suggested processive elongation of the nascent polymer, whereas Cps1B-ΔTPR appeared to work in a more distributive manner. The dispersity of the synthesized products could be reduced by generating single-action transferases and immobilizing them on individual columns, separating the two catalytic activities. Furthermore, we identified the O-acetyltransferase Cps1D of App1 and used it to modify the polymers produced by Cps1B. Two-dimensional NMR analyses of the products revealed O-acetylation levels identical to those of polymer harvested from App1 culture supernatants. In conclusion, we have established a protocol for the pathogen-free in vitro synthesis of tailored, nature-identical App1 capsule polymers.




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Glycation-mediated inter-protein cross-linking is promoted by chaperone-client complexes of {alpha}-crystallin: Implications for lens aging and presbyopia [Glycobiology and Extracellular Matrices]

Lens proteins become increasingly cross-linked through nondisulfide linkages during aging and cataract formation. One mechanism that has been implicated in this cross-linking is glycation through formation of advanced glycation end products (AGEs). Here, we found an age-associated increase in stiffness in human lenses that was directly correlated with levels of protein–cross-linking AGEs. α-Crystallin in the lens binds to other proteins and prevents their denaturation and aggregation through its chaperone-like activity. Using a FRET-based assay, we examined the stability of the αA-crystallin–γD-crystallin complex for up to 12 days and observed that this complex is stable in PBS and upon incubation with human lens–epithelial cell lysate or lens homogenate. Addition of 2 mm ATP to the lysate or homogenate did not decrease the stability of the complex. We also generated complexes of human αA-crystallin or αB-crystallin with alcohol dehydrogenase or citrate synthase by applying thermal stress. Upon glycation under physiological conditions, the chaperone–client complexes underwent greater extents of cross-linking than did uncomplexed protein mixtures. LC-MS/MS analyses revealed that the levels of cross-linking AGEs were significantly higher in the glycated chaperone–client complexes than in glycated but uncomplexed protein mixtures. Mouse lenses subjected to thermal stress followed by glycation lost resilience more extensively than lenses subjected to thermal stress or glycation alone, and this loss was accompanied by higher protein cross-linking and higher cross-linking AGE levels. These results uncover a protein cross-linking mechanism in the lens and suggest that AGE-mediated cross-linking of α-crystallin–client complexes could contribute to lens aging and presbyopia.




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Processivity of dextransucrases synthesizing very-high-molar-mass dextran is mediated by sugar-binding pockets in domain V [Glycobiology and Extracellular Matrices]

The dextransucrase DSR-OK from the Gram-positive bacterium Oenococcus kitaharae DSM17330 produces a dextran of the highest molar mass reported to date (∼109 g/mol). In this study, we selected a recombinant form, DSR-OKΔ1, to identify molecular determinants involved in the sugar polymerization mechanism and that confer its ability to produce a very-high-molar-mass polymer. In domain V of DSR-OK, we identified seven putative sugar-binding pockets characteristic of glycoside hydrolase 70 (GH70) glucansucrases that are known to be involved in glucan binding. We investigated their role in polymer synthesis through several approaches, including monitoring of dextran synthesis, affinity assays, sugar binding pocket deletions, site-directed mutagenesis, and construction of chimeric enzymes. Substitution of only two stacking aromatic residues in two consecutive sugar-binding pockets (variant DSR-OKΔ1-Y1162A-F1228A) induced quasi-complete loss of very-high-molar-mass dextran synthesis, resulting in production of only 10–13 kg/mol polymers. Moreover, the double mutation completely switched the semiprocessive mode of DSR-OKΔ1 toward a distributive one, highlighting the strong influence of these pockets on enzyme processivity. Finally, the position of each pocket relative to the active site also appeared to be important for polymer elongation. We propose that sugar-binding pockets spatially closer to the catalytic domain play a major role in the control of processivity. A deep structural characterization, if possible with large-molar-mass sugar ligands, would allow confirming this hypothesis.




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Structural basis of substrate recognition and catalysis by fucosyltransferase 8 [Protein Structure and Folding]

Fucosylation of the innermost GlcNAc of N-glycans by fucosyltransferase 8 (FUT8) is an important step in the maturation of complex and hybrid N-glycans. This simple modification can dramatically affect the activities and half-lives of glycoproteins, effects that are relevant to understanding the invasiveness of some cancers, development of mAb therapeutics, and the etiology of a congenital glycosylation disorder. The acceptor substrate preferences of FUT8 are well-characterized and provide a framework for understanding N-glycan maturation in the Golgi; however, the structural basis of these substrate preferences and the mechanism through which catalysis is achieved remain unknown. Here we describe several structures of mouse and human FUT8 in the apo state and in complex with GDP, a mimic of the donor substrate, and with a glycopeptide acceptor substrate at 1.80–2.50 Å resolution. These structures provide insights into a unique conformational change associated with donor substrate binding, common strategies employed by fucosyltransferases to coordinate GDP, features that define acceptor substrate preferences, and a likely mechanism for enzyme catalysis. Together with molecular dynamics simulations, the structures also revealed how FUT8 dimerization plays an important role in defining the acceptor substrate-binding site. Collectively, this information significantly builds on our understanding of the core fucosylation process.




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ADAM10 and ADAM17 proteases mediate proinflammatory cytokine-induced and constitutive cleavage of endomucin from the endothelial surface [Membrane Biology]

Contact between inflammatory cells and endothelial cells (ECs) is a crucial step in vascular inflammation. Recently, we demonstrated that the cell-surface level of endomucin (EMCN), a heavily O-glycosylated single-transmembrane sialomucin, interferes with the interactions between inflammatory cells and ECs. We have also shown that, in response to an inflammatory stimulus, EMCN is cleared from the cell surface by an unknown mechanism. In this study, using adenovirus-mediated overexpression of a tagged EMCN in human umbilical vein ECs, we found that treatment with tumor necrosis factor α (TNF-α) or the strong oxidant pervanadate leads to loss of cell-surface EMCN and increases the levels of the C-terminal fragment of EMCN 3- to 4-fold. Furthermore, treatment with the broad-spectrum matrix metalloproteinase inhibitor batimastat (BB94) or inhibition of ADAM metallopeptidase domain 10 (ADAM10) and ADAM17 with two small-molecule inhibitors, GW280264X and GI254023X, or with siRNA significantly reduced basal and TNFα-induced cell-surface EMCN cleavage. Release of the C-terminal fragment of EMCN by TNF-α treatment was blocked by chemical inhibition of ADAM10 alone or in combination with ADAM17. These results indicate that cell-surface EMCN undergoes constitutive cleavage and that TNF-α treatment dramatically increases this cleavage, which is mediated predominantly by ADAM10 and ADAM17. As endothelial cell-surface EMCN attenuates leukocyte–EC interactions during inflammation, we propose that EMCN is a potential therapeutic target to manage vascular inflammation.




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Re: Prognosis of unrecognised myocardial infarction determined by electrocardiography or cardiac magnetic resonance imaging: systematic review and meta-analysis




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A real opportunity to improve neurology services in England