Sunday, June 09, 2024

UK

 

‘A dangerous waste’: CND condemns Starmer’s commitment to nuclear weapons and militarism


“It’s time for a change of policy. The old one has failed – we need to look to the future with a vision to work for peace internationally, improve people’s lives & make us genuinely secure, not an impoverished nuclear target.”
Kate Hudson, CND

By the Campaign For Nuclear Disarmament

CND condemns Keir Starmer and Labour’s commitment to a “triple lock” on Britain’s nuclear weapons, as well as the decision to keep the Tory government’s pledge to spend 2.5% of our GDP on Britain’s military.

Speaking in the north-west of England today, Starmer maintains that Britain will build four new nuclear-armed Dreadnought submarines to replace the current Vanguard fleet, will keep one vessel permanently at-sea and able to launch a nuclear attack, and commits Labour to upgrading the fleet throughout its lifetime. CND estimates the lifetime cost of the Dreadnought programme will be at least £205 billion.

Starmer added that Labour in power will maintain Rishi Sunak’s promise to spend 2.5% of GDP “as soon as resources allow.” During the last budget, the Conservatives said this pledge would be met by 2030 – amounting to £87 billion per year.

CND General Secretary Kate Hudson said:

“After 14 years of Tory misrule, the Labour party has the opportunity to present a bold new security vision to the electorate. However, this policy just mirrors that of the existing government – more war, more military spending and more nuclear weapons. Patently obviously this approach is not bringing peace and prosperity in its wake. On the contrary. Billions are being wasted that should be rebuilding our decaying public services and improving people’s lives. It’s time for a change of policy. The old one has failed – we need to look to the future with a vision to work for peace internationally, improve people’s lives and make us genuinely secure, not an impoverished nuclear target.”

CND Chair Tom Unterrainer said:

“Keir Starmer is trying to make this election about security but has given no justification for how nuclear weapons ensure this. The risk of nuclear war has risen exponentially in the last two years but he offers no real account for how this has developed. For a man who claims to care about international law, there is no mention how expanding and modernising Britain’s nuclear arsenal goes against these norms. We need a bold vision for what real security means: one that puts climate, food security, and people at its heart, not more militarism and conflict.”




‘Change’ means ditching the two-party consensus on nukes

‘As the election goes on, let’s continue to oppose the rush to war and argue for proper investment in people and our public services’

Ben Hayes

Labour Outlook’s Ben Hayes writes on Starmer’s latest election commitment to nuclear weapons.

It has become a regular fixture of general election coverage for journalists to ask in lurid tones whether party leaders would be willing to use Britain’s nuclear weapons arsenal, consigning potentially millions of people to a painful death, and many more to life-changing injuries. That was the context when, yesterday, as the parties hit their campaigning stride, Keir Starmer said he would be prepared to push the nuclear button and outlined his “triple-lock commitment” to maintaining Britain’s nuclear weapons system. Despite a campaign slogan of “change”, this puts Labour frontbench policy broadly in line with the Tory Party on the issue of military spending and nuclear weapons.

The announcement recommits him to a pledge in the Daily Mail some weeks ago, accompanied by a promise not only to complete the new Dreadnought class submarines at Barrow, but maintain a continuous-at-sea nuclear weapons operation, and to deliver upgrades in the future – despite an on-paper pledge to achieve nuclear disarmament.

It can be seen as part of a wider view – expressed in the I newspaper – that a Labour government would seek to increase military spending to 2.5% of GDP. This would carry our military spending not only above NATO’s demand of 2% of GDP but above the 2.3% figure the Conservative government has already committed for the current year. The announcement by Rishi Sunak that UK defence spending will reach 2.5% of GDP by 2025 is evidence of an arms race between the two main parties.

It comes as the doomsday clock – monitored and examined by the Bulletin of Atomic Scientists – is set at 90 seconds to midnight, the closest we have ever stood towards catastrophe since the bulletin was created by Einstein and Oppenheimer in the 1940s. The bulletin itself has attributed this to the continuing war in Ukraine, the continuation of the global climate breakdown, and the potential for the ongoing attacks on Gaza to transform into a broader regional conflict as we have already seen through the Israeli attacks on Yemen and Iran.

Britain, whilst spending less than a tenth of the US budget – the world’s largest – already has the largest military budget in Europe at around £52bn per year and remains close to Russian spending levels before the Ukraine conflict, despite Russia’s huge nuclear arsenal. The Dreadnought submarine programme to deliver British nuclear weapons is estimated by the Ministry of Defence to cost £31bn but the programme has already spent 20% of a further £10bn allocated as contingency. The Campaign for Nuclear Disarmament estimates its lifetime cost at over £200billion.

The nuclear weapons programme is one of numerous major projects to enhance British war-fighting capabilities. Other commitments include fixing the troubled Elizabeth-class aircraft carriers and other navy ships, addressing the delays in developing the Ajax fighting vehicle and other army transport, and servicing the AUKUS Treaty submarine alliance with Australia. The National Audit Office has said the Ministry of Defence’s 2023 Equipment Plan is ‘unaffordable’, hence the need to drive a spending arms race by the main political parties.

The prioritisation of weapons spending is having a dramatic effect on both the current living conditions and the potential futures of young people across Britain and Europe more broadly. While the two largest-spending government departments, health and education, are formally declared as ‘protected’ from spending cuts, the reality is that both are suffering. Other departments providing vital public services, particularly local government and housing, face major cuts in the coming years.

Research from Unison shows that councils in Britain and the devolved nations face a collective funding shortfall of £3.56 billion for the coming financial year with many effectively becoming bankrupt. This funding shortfall has seen many essential public services cut to the bone, such as in Nottingham, where the council is threatening “the closure of our libraries, community centres, and the loss of 500 jobs directly” over the next six months.

There is a similar picture in education. We’ve seen the increase in the number of Free School Meal (FSM) eligible students soar to over 2 million eligible students across Britain in early 2024. We know that at least £12.2bn is needed to restore school spending power just to 2010 levels nationally. This chronic lack of funding has clearly had an impact on schools this year with children in more than 100 schools not being able to start school on time in September because ceilings were falling in and posing a risk to their lives.

The spending war over the defence budget stands in stark contrast. The British government has always, and even now continues, to drum up funds for war and militarisation with reports that Ministry of Defence spending topped £25bn for the first time in the last financial year. All this, while public sector trade unionists in Unison, the RCN, the BMA, the NEU or PCS are repeatedly told there is no money for a much deserved and earned increase in pay or investment in their services.

It’s vital that socialists and progressives inside and outside the Labour party and across the movement reject the prioritisation of warfare over public services, and urgently take up the cause of peace. Join the demonstrations, such as for a ceasefire in Gaza and an arms embargo of Israel; strengthen organisations such as the Campaign for Nuclear Disarmament and Stop the War Coalition by affiliating your union or party branches or organisations; and support motions calling for our movement to stand against increased military spending. As the election goes on, let’s continue to oppose the rush to war and argue for proper investment in people and our public services.


  • Ben Hayes is a regular contributor to Labour Outlook

 UK

Junior doctors take strike action ahead of General Election


By the BMA media team

Junior doctors in England have announced new strike dates ahead of the General Election as Rishi Sunak continues to refuse to meet junior doctors’ demands for a roadmap to restore pay lost over the last 15 years.  

After 3 months of talks between junior doctors in England and the Government, the Prime Minister has still made no credible offer to junior doctors.   

After the general election was called last week the BMA gave the Government a final opportunity to make an offer and avoid strikes. This opportunity has not been taken up. 

As a result, the BMA’s junior doctors committee has decided to announce further strike dates which will take place in the run up to the General Election. This will involve a full walkout by junior doctors beginning at 7am 27th June 2024 and ending 7am 2nd July. 

BMA junior doctors committee co-chairs Dr Robert Laurenson and Dr Vivek Trivedi said:  

“We made clear to the Government that we would strike unless discussions ended in a credible pay offer. For more than 18 months we have been asking Rishi Sunak to put forward proposals to restore the pay junior doctors have lost over the past 15 years – equal to more than a quarter in real terms.  

“When we entered mediation with Government this month we did so under the impression that we had a functioning government that would soon be making an offer. Clearly no offer is now forthcoming. Junior doctors are fed up and out of patience. 

“Even at this late stage Mr Sunak has the opportunity to show that he cares about the NHS and its workers. It is finally time for him to make a concrete commitment to restore doctors’ pay. If during this campaign he makes such a public commitment that is acceptable to the BMA’s junior doctors committee, then no strikes need go ahead.”


  • This article was originally published by the BMA on 29 May, 2024.
  • The British Medical Association (BMA) is a professional association and trade union representing and negotiating on behalf of all doctors in the UK. You can follow the BMA on FacebookTwitter and Instagram.

 

A massive triumph for the Left in Mexico


By David Raby

On Sunday 2 June Mexico held general elections, for President, both Houses of Congress, eight State Governorships plus the Head of Government (Metro Mayor) of Mexico City, and hundreds of local positions.

The result was a stunning victory for the left: Claudia Sheinbaum, candidate of the governing Morena (Movement of National Regeneration) Party, won with 60% against 29% for her main right-wing opponent, Xóchitl Gálvez; Morena and its two allied parties won six of the eight governorships and the all-important Metro Mayor position; and while detailed results remain to be confirmed, Morena and its allies won between 84 and 88 out of 128 Senate seats and between 370 and 380 out of 500 seats in the Lower House of Congress.

The significance of the Senate and House figures is that in order to enact Constitutional amendments it is necessary to have a two-thirds majority in both Houses of Congress, and this is key for AMLO’s (and Claudia’s) plans to reform the extremely corrupt judicial system, among other things. The figures are in the range of the two-thirds majorities.

Opinion polls had in fact been predicting this for months, but few dared to believe it. Incessant and vitriolic hostile propaganda from the right created a tense atmosphere although it failed completely to win over Mexican voters, in fact it had a boomerang effect and provoked more people to support Claudia and Morena.

The real target of right-wing propaganda (most of it patently false) was international opinion, above all Western governments, politicians and business interests. Millions of social media memes like #NarcoPresidente were followed up by a cascade of negative media articles in the NY Times, Washington Post, Financial Times and other mainstream outlets.

What AMLO (outgoing President Andrés Manuel López Obrador) and Morena had achieved over the past five and a half years of his six-year term has no parallel in Latin America. Honesty and modesty in government, a serious attack on corruption which he denounced as the root of Mexico’s problems, creation for the first time of a true welfare state, protection of Mexican sovereignty while maintaining cordial relations with the US: all of this was accompanied by constant communication and dialogue with the people.

Also he achieved economic growth and financial stability, financing programmes by reinforcing tax collection without raising tax rates and without borrowing. His bold progressive foreign policy favouring Latin American unity, saving Evo Morales’ life in 2019 and actively condemning the blockade of Cuba, leaves no doubt as to where he stands.

Despite his enormous popularity AMLO always insisted that he would not seek re-election, and this had the effect of forcing Morena to organise more effectively as a mass party and to address the question of the succession. Claudia Sheinbaum emerged during the past year through a process of internal party debate and consultation; she had been a comrade of AMLO in popular and political struggles for some 25 years, with an impeccable leftist record as well as scientific training in environmental sciences, and a firm identification with socialist feminism. She had an excellent record as Metro Mayor of the capital for five years.

The rise of the extreme right in recent years in Latin America (indeed the world) inevitably aroused doubt and fear about Mexico’s prospects. But having followed the process closely I was confident that AMLO and his “4T” (Fourth Transformation) process had immunised Mexico against the far right. After arriving on May 28 for this latest visit, my optimism was confirmed.

Small and medium business owners typically favoured the conservative PAN (National Action Party, a key actor in the opposition coalition), but not always: a restaurant owner wanted welfare policies for the good of all to continue. Also a self-employed beautician was absolutely committed to AMLO, Claudia and the Transformation.

On Sunday long queues formed at polling stations across the country, and people I interviewed in a working-class neighbourhood of the capital were almost unanimously in favour of Claudia and the Transformation. It was clear the the turnout would be high, confirming the virtual certainty of a decisive victory for Morena and its allies.

Voters queue for the polls in Mexico on June 2nd, 2024. Photo credit: David Raby.

When the polls closed Xóchitl and her team immediately claimed to have won, an absurd claim since the count had barely begun and exit polls suggested a two-to-one majority for Claudia. The worrying element of this was that Xóchitl hinted they would contest the results in the courts.

But by 11pm the official “quick count” confirmed a big lead for Claudia and Morena, and around midnight Xóchitl did a U-turn and admitted defeat. Messages of congratulations were already pouring in to Claudia Sheinbaum from Heads of State and progressive leaders around the world, and a huge enthusiastic victory celebration took place in the central Zócalo.

Victory also for Clara Brugada, a progressive community leader who had previously been Mayor of the huge working-class Iztapalapa borough, was very positive: she won with about 51 to 40% over a notorious corrupt opponent, Santiago Taboada. Women’s rights, above all for indigenous, working and peasant women, are high on Claudia’s list of priorities.

Claudia had no hesitation in reaffirming her identification with AMLO’s principles and legacy, and when media critics suggest she is just his puppet, she dismisses them with scorn. Of course she wants to continue his programme “For the good of all, but first, the poor”; she believes like him in the primacy of the public good over private profit and in Mexican sovereignty. But she is her own person with her own goals, and on Sunday night in her victory speech, her self-confidence was clearer than ever.

Mexico’s triumph brings hope to Latin America and the world, and needs to be celebrated as an example for the demoralised left in the UK and Europe.


  • David L Raby is a retired Professor of Latin American Studies (Toronto and Liverpool), Coordinator of the Mexico Solidarity Forum and author of “Democracy and Revolution: Latin America and Socialism Today” (London, 2006: Pluto).
  • You can follow David Raby on Twitter/X and find out more about the campaign of the Mexico Solidarity Forum here.

 

Shape and depth of ocean floor profoundly influence how carbon is stored there


New study finds seafloor topography accounts for up to 50% of the changes in depth at which carbon has been sequestered



UNIVERSITY OF CALIFORNIA - LOS ANGELES




Key takeaways

  • The movement of carbon between the atmosphere, oceans and continents — or carbon cycle — regulates Earth’s climate, with the ocean playing a major role in carbon sequestration.
  • A new study finds that the shape and depth of the ocean floor explain up to 50% of the changes in depth at which carbon has been sequestered there over the past 80 million years.
  • While these changes have been previously attributed to other causes, the new finding could inform ongoing efforts to combat climate change through marine carbon sequestration.

    The movement of carbon between the atmosphere, oceans and continents — the carbon cycle — is a fundamental process that regulates Earth’s climate. Some factors, like volcanic eruptions or human activity, emit carbon dioxide into the atmosphere. Others, such as forests and oceans, absorb that CO2. In a well-regulated system, the right amount of CO2 is emitted and absorbed to maintain a healthy climate. Carbon sequestration is one tactic in the current battle against climate change.

    new study finds that the shape and depth of the ocean floor explain up to 50% of the changes in depth at which carbon has been sequestered in the ocean over the past 80 million years. Previously, these changes have been attributed to other causes. Scientists have long known that the ocean, the largest absorber of carbon on Earth, directly controls the amount of atmospheric carbon dioxide. But, until now, exactly how changes in seafloor topography over Earth’s history affect the ocean’s ability to sequester carbon was not well understood.

    “We were able to show, for the first time, that the shape and depth of the ocean floor play major roles in the long-term carbon cycle,” said Matthew Bogumil, the paper’s lead author and a UCLA doctoral student of earth, planetary and space sciences.

    The long-term carbon cycle has a lot of moving parts, all functioning on different time scales. One of those parts is seafloor bathymetry — the mean depth and shape of the ocean floor. This is, in turn, controlled by the relative positions of the continent and the oceans, sea level, as well as the flow within Earth’s mantle. Carbon cycle models calibrated with paleoclimate datasets form the basis for scientists’ understanding of the global marine carbon cycle and how it responds to natural perturbations

    “Typically, carbon cycle models over Earth’s history consider seafloor bathymetry as either a fixed or a secondary factor,” said Tushar Mittal, the paper’s co-author and a professor of geosciences at Pennsylvania State University.

    The new research, published in Proceedings of the National Academy of Sciences, reconstructed bathymetry over the last 80 million years and plugged the data into a computer model that measures marine carbon sequestration. The results showed that ocean alkalinity, calcite saturation state and the carbonate compensation depth depended strongly on changes to shallow parts of the ocean floor (about 600 meters or less) and on how deeper marine regions (greater than 1,000 meters) are distributed. These three measures are critical to understanding how carbon is stored in the ocean floor.

    The researchers also found that for the current geologic era, the Cenozoic, bathymetry alone accounted for 33%–50% of the observed variation in carbon sequestration and concluded that by ignoring bathymetric changes, researchers mistakenly attribute changes in carbon sequestration to other, less certain factors, such as atmospheric CO2, water column temperature, and silicates and carbonates washed into the ocean by rivers.

    “Understanding important processes in the long-term carbon cycle can better inform scientists working on marine-based carbon dioxide removal technologies to combat climate change today,” Bogumil said. “By studying what nature has done in the past, we can learn more about the possible outcomes and practicality of marine sequestration to mitigate climate change.”

    This new understanding that the shape and depth of ocean floors is perhaps the greatest influencer of carbon sequestration can also aid the search for habitable planets in our universe.

    “When looking at faraway planets, we currently have a limited set of tools to give us a hint about their potential for habitability,” said co-author Carolina Lithgow-Bertelloni, a UCLA professor and department chair of earth, planetary and space sciences. “Now that we understand the important role bathymetry plays in the carbon cycle, we can directly connect the planet’s interior evolution to its surface environment when making inferences from JWST observations and understanding planetary habitability in general.”

    The breakthrough represents only the beginning of the researchers’ work.

    “Now that we know how important bathymetry is in general, we plan to use new simulations and models to better understand how differently shaped ocean floors will specifically affect the carbon cycle and how this has changed over Earth’s history, especially the early Earth, when most of the land was underwater,” Bogumil said.

     

    Crisis intervention program leverages socialmedia to reduce suicide risk


    Study by OHSU, Lines for Lifeocuments innovative intervention for youth through Safe Social Spaces program



    Peer-Reviewed Publication

    OREGON HEALTH & SCIENCE UNIVERSITY





    An Oregon-based program that monitors social media use may have helped deter more than 150 youth suicide attempts in the five years it’s operated, reports a new study published online today in the journal Psychiatric Services.

    Staff with Lines for Life, a nonprofit that operates mental health crisis support services, and researchers at Oregon Health & Science University collaborated to closely document interventions by the Safe Social Spaces program, launched in 2019 by Lines for Life.

    The study’s senior author said it’s an example of meeting people where they are.

    “Community engagement is critical,” said Alan Teo, M.D., M.S., associate professor of psychiatry in the OHSU School of Medicine. “Health care systems often wait for patients to come to the clinic or hospital, but if you just wait for patients to come to you, there are a lot of people in need who will be missed.”

    Whatever its role in driving the mental health crisis affecting young people, the new study suggests, social media can be used as a unique tool in detecting concerning messages for those paying attention.

    In this case, trained staff with the Safe Social Spaces intervention program contacted more than 3,000 young people who openly shared their experience with emotional problems on social media. The program estimates that, through supportive dialogue, 163 instances of self-harm, which can include suicide attempts, have been avoided so far.

    Teo acknowledged the irony of using social media to achieve a positive mental health outcome.

    “Experiences on social media can be stressful, but what I love about this program is that it illustrates a way to use forums online for a good purpose,” Teo said. “It’s obviously not as black and white as saying social media is evil or screen time is all bad. We know that youth are spending time there and, as with all technologies, the important thing is in how you use it.”

    In addition to Teo, co-authors on the study included Laura Levy, a graduating M.D.-M.P.H. student in the OHSU School of Medicine and the OHSU-Portland State University School of Public Health, and Angela Nielsen of Lines for Life.

    Teo serves as a staff psychiatrist in the VA Portland Health Care System and his research is supported by the Veterans Health Administration Office of Research and Development, Health Systems Research.

    Fish out of water: How killifish embryos adapted their development



    UNIVERSITY OF BASEL
    killifish embryos 

    IMAGE: 

    KILLIFISH EMBRYOS UNDER A FLUORESCENCE MICROSCOPE. LEFT WITH A DEVELOPED AXIS, RIGHT WITHOUT FORMATION OF THE AXIS. THE CELLS REMAIN DISPERSED.

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    CREDIT: BIOZENTRUM, UNIVERSITY OF BASEL





    The annual killifish lives in regions with extreme drought. A research group at the University of Basel now reports in “Science” that the early embryogenesis of killifish diverges from that of other species. Unlike other fish, their body structure is not predetermined from the outset. This could enable the species to survive dry periods unscathed.

    The turquoise killifish inhabits areas characterized by extreme conditions. The species, native to Africa, can survive prolonged periods of drought due to its unique life cycle. During humid periods, they lay their fertilized eggs in the mud. When the waters dry out, the adult fish die, while the embryos remain dormant in the dry mud by entering diapause. Once the rain falls, the embryo’s development continues.

    In contrast to other animals, the early embryos of killifish completely disperse into individual cells, which later aggregate to form the body axes and the embryo proper. The killifish species Nothobranchius furzeri has thus adapted its embryogenesis and life cycle to its environmental conditions.

    Dorsal-ventral body axis
    Prof. Alex Schier's team at the Biozentrum, University of Basel, and researchers from Harvard University and the University of Washington in Seattle have discovered that killifish early embryogenesis differs from other fish species also at the molecular level. “Normally, the dorsal-ventral body axis, i.e. the back and the belly of the fish embryo, is already determined by the mother,” says Schier. “We have discovered that embryonic cells of killifish are not maternally pre-patterned, but self-organize to form the body axis.” In their recent publication in “Science”, the researchers describe how the dorsal-ventral axis is formed in killifish.

    The so-called Huluwa factor plays a decisive role in early embryonic development in fish. It is passed on from the mother to the embryo and dictates the dorsal-ventral body axis. This is crucial for morphogenesis as well as the correct formation and positioning of organs.

    “Previously, it was assumed that Huluwa is indispensable for axis formation,” explains Schier. “We have now been able to show that this factor is inactive in killifish. The embryonic cells find the right place on their own, they completely self-organize after dissociation.” In contrast to other fish, the determination of the dorsal-ventral axis in killifish occurs at a later stage and is regulated by embryonic factors. “The embryo emerges almost magically,” says Schier. “How exactly this happens still remains unclear.”

    Well adapted to extreme environmental conditions
    “Among fish, annual killifish have an atypical embryonic development that challenges the current concepts of axis formation,” says Schier. The absence of maternal pre-patterning in killifish embryos may offer a survival advantage, preventing the accumulation of damaged cells during dry seasons or the loss of body structure information. “Our study shows that evolution finds alternative developmental routes under selective pressures imposed by extreme environments,” concludes Schier.

     

    Silkworms help grow better organ-like tissues in labs


    A new ultrathin silk membrane for organ-on-a-chip platforms helps cells communicate and grow into functional tissues used for research



    DUKE UNIVERSITY

    Membrane Cross Section 

    IMAGE: 

    SCANNING ELECTRON MICROGRAPHS SHOW THE DETAILED FIBERS OF THE SF MEMBRANES

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    CREDIT: XINGRUI MOU & SAMIRA MUSAH, DUKE UNIVERSITY




    DURHAM, N.C. -- Biomedical engineers at Duke University have developed a silk-based, ultrathin membrane that can be used in organ-on-a-chip models to better mimic the natural environment of cells and tissues within the body. When used in a kidney organ-on-a-chip platform, the membrane helped tissues grow to recreate the functionality of both healthy and diseased kidneys.

    By allowing the cells to grow closer together, this new membrane helps researchers to better control the growth and function of the key cells and tissues of any organ, enabling them to more accurately model a wide range of diseases and test therapeutics.

    The research appears June 4 in the journal Science Advances.

    Often no larger than a USB flash drive, organ-on-a-chip (OOC) systems have revolutionized how researchers study the underlying biology of the human body, whether it’s creating dynamic models of tissue structures, studying organ functions or modeling diseases. These platforms are designed to stimulate cell growth and differentiation in a way that best mimics the organ of interest. Researchers can even populate these tools with human stem cells to generate patient-specific organ models for pre-clinical studies.

    But as the technology has evolved, problems in the chip’s design have also emerged –– most notably with the materials used to create the membranes that form the support structure for the specialized cells to grow on. These membranes are typically composed of polymers that don’t degrade, creating a permanent barrier between cells and tissues. While the extracellular membranes in human organs are often less than one micron thick, these polymer membranes are anywhere from 30 to 50 microns, hindering communication between cells and limiting cell growth.

    “We want to handle the tissues in these chips just like a pathologist would handle biopsy samples or even living tissues from a patient, but this wasn’t possible with the standard polymer membranes because the extra thickness prevented the cells from forming structures that more closely resemble tissues in the human body,” said Samira Musah, an assistant professor of biomedical engineering and medicine at Duke. “We thought, ‘Wouldn’t it be nice if we could get a protein-based material that mimics the structure of these natural membranes and is thin enough for us to slice and study?’”

    This question led Musah and George (Xingrui) Mou, a PhD student in Musah’s lab and first author on the paper, to silk fibroin, a protein created by silkworms that can be electronically spun into a membrane. When examined under a microscope, silk fibroin looks like spaghetti or a Jackson Pollock painting. Made out of long, intertwining fibers, the porous material better mimics the structure of the extracellular matrix found in human organs, and it has previously been used to create scaffolds for purposes like wound healing.

    “The silk fibroin allowed us to bring the membrane thickness down from 50 microns to five or fewer, which gets us an order of magnitude closer to what you’d see in a living organism,” explained Mao.

    To test this new membrane, Musah and Mao applied the material to their kidney chip models. Made out of a clear plastic and roughly the size of a quarter, this OOC platform is meant to resemble a cross section of a human kidney––specifically the glomerular capillary wall, a key structure in the organ made from clusters of blood vessels that is responsible for filtering blood.

    Once the membrane was in place, the team added human induced pluripotent stem cell derivatives into the chip. They observed that these cells were able to send signals across the ultrathin membrane, which helped the cells differentiate into glomerular cells, podocytes and vascular endothelial cells. The platform also triggered the development of endothelial fenestrations in the growing tissue, which are holes that allow for the passage of fluid between the cellular layers.

    By the end of the test, these different kidney cell types had assembled into a glomerular capillary wall and could efficiently filter molecules by size.

    “The new microfluidic chip system's ability to simulate in vivo-like tissue-tissue interfaces and induce the formation of specialized cells, such as fenestrated endothelium and mature glomerular podocytes from stem cells, holds significant potential for advancing our understanding of human organ development, disease progression, and therapeutic development,” said Musah.

    As they continue to optimize their model, Musah and colleagues are hoping to use this technology to better understand the mechanisms behind kidney disease. Despite affecting more than 15 percent of American adults, researchers lack effective models for the disease. Patients are also often not diagnosed until the kidneys have been substantially damaged, and they are often required to undergo dialysis or receive a kidney transplant.

    “Using this platform to develop kidney disease models could help us discover new biomarkers of the disease,” said Mao. “This could also be used to help us screen for drug candidates for several kidney disease models. The possibilities are very exciting.”

    “This technology has implications for all organ-on-a-chip models,” said Musah. “Our tissues are made up of membranes and interfaces, so you can imagine using this membrane to improve models of other organs, like the brain, liver, and lungs, or other disease states. That’s where the power of our platform really lies.”

    This work was supported by a Whitehead Scholarship in Biomedical Research, Chair’s Research Award from the Department of Medicine at Duke University, MEDx Pilot Grant on Biomechanics in Injury or Injury Repair, Burroughs Wellcome Fund PDEP Career Transition Ad Hoc Award, Duke Incubation Fund from the Duke Innovation & Entrepreneurship Initiative, Genetech Research Award, a George M. O’Brien Kidney Center Pilot Grant (P30 DK081943), an NIH Director’s New Innovator Grant (DP2DK138544).

    CITATION: “An Ultrathin Membrane Mediates Tissue-Specific Morphogenesis and Barrier Function in a Human Kidney Chip,” Xingrui Mou, Jessica Shah, Yasmin Roye, Carolyn Du, Samira Musah. Science Advances. June 4, 2024. DOI: https://doi.org/10.1126/sciadv.adn2689

     

    Scientists ‘read’ the messages in chemical clues left by coral reef inhabitants



    AMERICAN CHEMICAL SOCIETY
    Scientists ‘read’ the messages in chemical clues left by coral reef inhabitants 

    IMAGE: 

    A NEW WAY TO COLLECT COMPOUNDS FROM SEAWATER HELPED RESEARCHERS IDENTIFY THREE METABOLITES RELATED TO CORAL REEFS’ INHABITANTS AND POTENTIAL DISEASE STATE.

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    CREDIT: AMY APPRILL




    What species live in this coral reef, and are they healthy? Chemical clues emitted by marine organisms might hold that information. But in underwater environments, invisible compounds create a complex “soup” that is hard for scientists to decipher. Now, researchers in ACS’ Journal of Proteome Research have demonstrated a way to extract and identify these indicator compounds in seawater. They found metabolites previously undetected on reefs, including three that may represent different reef organisms.

    Plants and animals living in coral reefs release various substances, from complex macromolecules to individual amino acids, into the surrounding water. To determine which ones could identify the ecosystems’ inhabitants and be used to measure a coral reef’s health, scientists need to prepare water samples for analysis by concentrating the compounds and separating them from the salty broth. They primarily concentrate and collect these dissolved compounds from seawater on sticky membranes. However, this method misses many important nitrogen-, oxygen- and sulfur-containing compounds produced by marine organisms. These metabolites don’t attach well to the membrane materials and are present at extremely low levels in seawater. To overcome these challenges, Brianna Garcia, Amy Apprill, Elizabeth Kujawinski and colleagues at Woods Hole Oceanographic Institution tested a technique that modified the dissolved metabolites before they were extracted from seawater into a form that’s compatible with membrane materials allowing them to be concentrated and analyzed.

    First, the researchers collected and filtered water samples from five coral reefs around the U.S. Virgin Islands. They then used a series of reactions to attach a benzoyl functional group to dissolved amine- and alcohol-containing metabolites. Next, the team extracted the modified metabolites from the samples and assessed their composition and concentrations with liquid chromatography-mass spectrometry. From applying this new technique, the researchers identified 23 metabolites that hadn’t been identified near coral reefs by previous studies, including amino acids, amines, pyrimidine nucleosides and organosulfonic acids, which are involved in photosynthesis and organismal growth. When the researchers analyzed their data, they found that:

    • The presence of diseased coral, macroalgae and crustose coralline algae had the greatest influence on the metabolite compositions.
    • Some compounds, such as the organosulfonic acid called DHPS, were consistently at high levels in all locations, which suggests the presence of coral and associated organisms.
    • Three metabolites (homoserine betaine, tryptophan and γ-aminobutryic acid) had significantly different levels among the five reefs, and the researchers attribute those differences to variations in marine environments and organisms.

    The researchers say this study successfully demonstrates how to collect previously overlooked, ecologically relevant compounds in coral reef ecosystems that could be used to monitor them for effects from climate change, natural disturbances and disease activity.

    The authors acknowledge funding from the National Science Foundation and the National Oceanic & Atmospheric Administration’s Oceanic and Atmospheric Research Cooperative Institutes.

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