Sunday, 27 September 2020

Microplastics found in lungs

Does it cause cancer?


 https://cebp.aacrjournals.org/content/7/5/419



Abstract

We report the results of studies undertaken to determine whether inhaled plant (i.e., cellulosic; e.g., cotton) and plastic (e.g., polyester) fibers are present in human lungs and, if so, whether inhaled fibers are also present in human lung cancers. Specimens of lung cancer of different histological types and adjacent nonneoplastic lung tissue were obtained from patients undergoing a lung resection for removal of a tumor. With the protection of a laminar flow hood and safeguards to prevent contamination by extraneous fibers, fresh, nonfixed, and nonstained samples of lung tissue were compressed between two glass microscope slides. Specimens in these dual slide chambers were examined with a microscope configured to permit viewing with white light, fluorescent light, polarizing light, and phase-contrast illumination. Near-term fetal bovine lungs and nonlung human tumors were used as controls. In contrast to the observations of these control tissues, morphologically heterogeneous fibers were seen repetitively in freshly excised human lung tissue using polarized light. Inhaled fibers were present in 83% of nonneoplastic lung specimens (n = 67/81) and in 97% of malignant lung specimens (n = 32/33). Thus, of the 114 human lung specimens examined, fibers were observed in 99 (87%). Examination of histopathology slides of lung tissue with polarized light confirmed the presence of inhaled cellulosic and plastic fibers. Of 160 surgical histopathology lung tissue slides, 17 were selected for critical examination; of these, fibers were identified in 13 slides. The inhalation of mineral (e.g., asbestos) fibers has been described by many investigators; we believe, however, that this is the first report of inhaled nonmineral (e.g., plant and plastic) fibers. These bioresistant and biopersistent cellulosic and plastic fibers are candidate agents contributing to the risk of lung cancer.

Saturday, 26 September 2020

Cortical spreading depression of Leao




What does “aura” mean?

The term aura describes any neurological disturbance that appears shortly before or during the development of migraine headaches. Migraine with aura is a common type of migraine. The aura usually lasts less than 1 hour, and almost invariably fades away without long-lasting effects. The most common aura involves the vision, with hallucination/illusion of bright flashing lights and partial blindness.

Aura figure 1

This shows the brain’s level of electrical activity. Reading from left to right, we can see the spreading of CSD of electrical activity (detectable as a reduction of the recorded signals to a straight line) and the subsequent return to normal electrical activity over a 9 minute period (Modified from Leão AAP, Journal of Neurophysiology, 1944, with permission from the American Physiological Society).

The first description of migraine aura is attributed to the German abbess Hildegard of Bingen, a truly remarkable woman who lived in Rhineland in the 12th Century. At the age of 32, she began to receive ‘holy visions’, but some neurologists attribute her descriptions to the classic symptoms of migraine with aura (See front cover). By 1941, the characteristic symptoms of the visual aura had been well described, and it was known to result from a disturbance of the visual cortex rather than from a malfunction of the eye retina. However, that year, Karl Spencer Lashley, an eminent psychologist working at Harvard who suffered from migraines published an article that later turned out to be extremely important. Through a careful analysis of the sketches of his visual illusions, and especially by following their development, with time he was able to propose that the visual aura probably results from a wave of intense excitation of the visual cortex (producing the visual illusion of scintillations or bright flashes) followed by complete inhibition of activity (resulting in temporary and partial blindness). These disturbances move at a rate of about 3 millimetres per minute across this cortical region in the brain.
What is cortical spreading depression?

The scientific term cortical spreading depression (CSD) describes a local disturbance of the brain function that is characterised by a transient and local suppression (depression) of the spontaneous electrical activity in thecortex (cortical) that moves slowly across this brain region (spreading). Aristides A.P. Leão, a Brazilian studying for a PhD at Harvard University was the first to describe this phenomenon in 1944 (Figure 1). He made this discovery while studying epilepsy. One year later, a better characterisation of CSD, especially of its progression, allowed Leão and his colleague R.S. Morison to propose, for the first time, that the malfunction of cortical nerve cells suspected to cause the aura might well be CSD. Indeed, both the suspected nervous malfunction and CSD shared surprisingly many common properties.Aura figure 2

Spreading suppression of cortical activation during migraine aura. A – in the top left corner is a drawing showing the progression of the aura symptoms, as described by the patient. B is the origin of this brain anomaly as seen by functional MRI (fMRI). (Modified from Hadjikhani and collaborators, Proceedings of the National Academy of Sciences of the United States of America, April 2001, with permission of the authors and the National Academy of Sciences of the USA).
The working brain

Under normal conditions, brain cells use a complex biochemical mechanism to maintain very different levels of several ions on each side of their cellular membrane. For example, the level of potassium is much higher within the cells than outside, whereas it is the reverse for sodium and calcium. This capability, called brain ion homeostasis, is vital to the brain’s electrical activity (Figure 2). It is now well established that a temporary failure of this cellular ion homeostasis occurs during CSD, with potassium suddenly leaking out of the cells, whereas sodium and calcium enter the intracellular space. Hence, the initial malfunction leading to the spreading, local suppression of electrical activity is actually a migrating local failure of brain ion homeostasis.
The progress of science

The link between migraine aura and CSD was confirmed in the early 1980’s, with the development of clinical methods for the imaging of cerebral blood flow in patients. These new methods allowed a team of researchers in Copenhagen to demonstrate that a unique pattern of changes in local cerebral blood flow was associated with an attack of migraine with aura. In particular, they were able to observe that, at the beginning of such an attack, cerebral blood flow decreased in the posterior part of the brain (which is concerned with visual perception), with the low flow regions subsequently spreading into the more frontal brain regions at the rate of 2 to 3 millimetres per minute. This was precisely the rate of CSD propagation that was measured in animal models, and reduced blood flow was already known to be associated with experimental CSD. The recent, spectacular advances in magnetic resonance imaging (MRI) of brain function have provided a definitive confirmation of these findings.
The value of knowledge

CSD is now attracting increasing interest from neuroscientists in both academia and the pharmaceutical industry. Firstly, 50 years after its discovery, it was finally agreed that this phenomenon plays a key role in the genesis of migraine attacks, possibly even when it is not preceded by an aura (migraine without aura is the common type). Indeed, it is currently suspected that CSD, depending on where it occurs in the cortex, may not always be associated with a perceived aura. Secondly, as CSD appears as the initial trigger of migraine attacks, the discovery of drugs capable of suppressing this nervous disturbance would potentially lead to the development of medicines to prevent the initiation of migraine (prophylactic treatment), in contrast to most current anti-migraine drugs that only treat the subsequent headache.
The Remaining Challenges

At present, the most important task is the discovery of drugs that can suppress CSD. These will have to be well tolerated (without side effects) if they are to be used to prevent migraine, because migraineurs will have to take them repeatedly over a long period, just as epileptic patients take drugs to prevent their seizures.

Improving our understanding of how CSD can lead to headache is another research strategy that will certainly help with the discovery of new anti-migraine drugs. So far, we know that this involves a complex cascade of events that ultimately leads to the activation of pain-sensitive fibres in the brain, but the overall picture is far from complete.

Most studies on CSD are carried out in models and tissue preparations where CSD is elicited experimentally using strong external stimuli such as the application of potassium chloride or electrical stimulation of parts of the brain. But, in the brains of people with migraine, the aura occurs without such strong external stimuli. Therefore, a key question is: what predisposes the brain of migraineurs to spontaneous CSD? It is likely that several anomalies of the complex machinery associated with the brain cell membrane can promote the occurance of CSD, and this certainly includes several types of genetic anomalies. The discovery of these altered genes will dramatically improve our understanding of the genesis of migraine attacks. This scientific knowledge may allow us to tailor the treatment of migraine to the specific genetic predisposition of a given group of patients.The possibility for such a gene-directed therapy of migraine is certainly a worthwhile long-term objective.
Acknowledgements

The authors are grateful to Louise Shepherd from the Library of the Institute of Neurology (London) for providing them with ‘historic’ scientific literature.
Authors

Tiho P. Obrenovitch is Reader in Neuroscience at the Bradford School of Pharmacy. Jens P. Dreier is a Neurologist at the Charité University Medicine in Berlin, Germany. Both are actively engaged in research focused on cortical spreading depression.
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Bari Weiss resignation letter

 https://www.bariweiss.com/resignation-letter


Dear A.G.,

It is with sadness that I write to tell you that I am resigning from The New York Times. 

I joined the paper with gratitude and optimism three years ago. I was hired with the goal of bringing in voices that would not otherwise appear in your pages: first-time writers, centrists, conservatives and others who would not naturally think of The Times as their home. The reason for this effort was clear: The paper’s failure to anticipate the outcome of the 2016 election meant that it didn’t have a firm grasp of the country it covers. Dean Baquet and others have admitted as much on various occasions. The priority in Opinion was to help redress that critical shortcoming.

I was honored to be part of that effort, led by James Bennet. I am proud of my work as a writer and as an editor. Among those I helped bring to our pages: the Venezuelan dissident Wuilly Arteaga; the Iranian chess champion Dorsa Derakhshani; and the Hong Kong Christian democrat Derek Lam. Also: Ayaan Hirsi Ali, Masih Alinejad, Zaina Arafat, Elna Baker, Rachael Denhollander, Matti Friedman, Nick Gillespie, Heather Heying, Randall Kennedy, Julius Krein, Monica Lewinsky, Glenn Loury, Jesse Singal, Ali Soufan, Chloe Valdary, Thomas Chatterton Williams, Wesley Yang, and many others.

But the lessons that ought to have followed the election—lessons about the importance of understanding other Americans, the necessity of resisting tribalism, and the centrality of the free exchange of ideas to a democratic society—have not been learned. Instead, a new consensus has emerged in the press, but perhaps especially at this paper: that truth isn’t a process of collective discovery, but an orthodoxy already known to an enlightened few whose job is to inform everyone else.

Twitter is not on the masthead of The New York Times. But Twitter has become its ultimate editor. As the ethics and mores of that platform have become those of the paper, the paper itself has increasingly become a kind of performance space. Stories are chosen and told in a way to satisfy the narrowest of audiences, rather than to allow a curious public to read about the world and then draw their own conclusions. I was always taught that journalists were charged with writing the first rough draft of history. Now, history itself is one more ephemeral thing molded to fit the needs of a predetermined narrative.

My own forays into Wrongthink have made me the subject of constant bullying by colleagues who disagree with my views. They have called me a Nazi and a racist; I have learned to brush off comments about how I’m “writing about the Jews again.” Several colleagues perceived to be friendly with me were badgered by coworkers. My work and my character are openly demeaned on company-wide Slack channels where masthead editors regularly weigh in. There, some coworkers insist I need to be rooted out if this company is to be a truly “inclusive” one, while others post ax emojis next to my name. Still other New York Times employees publicly smear me as a liar and a bigot on Twitter with no fear that harassing me will be met with appropriate action. They never are.

There are terms for all of this: unlawful discrimination, hostile work environment, and constructive discharge. I’m no legal expert. But I know that this is wrong. 

I do not understand how you have allowed this kind of behavior to go on inside your company in full view of the paper’s entire staff and the public. And I certainly can’t square how you and other Times leaders have stood by while simultaneously praising me in private for my courage. Showing up for work as a centrist at an American newspaper should not require bravery.

Part of me wishes I could say that my experience was unique. But the truth is that intellectual curiosity—let alone risk-taking—is now a liability at The Times. Why edit something challenging to our readers, or write something bold only to go through the numbing process of making it ideologically kosher, when we can assure ourselves of job security (and clicks) by publishing our 4000th op-ed arguing that Donald Trump is a unique danger to the country and the world? And so self-censorship has become the norm.

What rules that remain at The Times are applied with extreme selectivity. If a person’s ideology is in keeping with the new orthodoxy, they and their work remain unscrutinized. Everyone else lives in fear of the digital thunderdome. Online venom is excused so long as it is directed at the proper targets. 

Op-eds that would have easily been published just two years ago would now get an editor or a writer in serious trouble, if not fired. If a piece is perceived as likely to inspire backlash internally or on social media, the editor or writer avoids pitching it. If she feels strongly enough to suggest it, she is quickly steered to safer ground. And if, every now and then, she succeeds in getting a piece published that does not explicitly promote progressive causes, it happens only after every line is carefully massaged, negotiated and caveated.

It took the paper two days and two jobs to say that the Tom Cotton op-ed “fell short of our standards.” We attached an editor’s note on a travel story about Jaffa shortly after it was published because it “failed to touch on important aspects of Jaffa’s makeup and its history.” But there is still none appended to Cheryl Strayed’s fawning interview with the writer Alice Walker, a proud anti-Semite who believes in lizard Illuminati. 

The paper of record is, more and more, the record of those living in a distant galaxy, one whose concerns are profoundly removed from the lives of most people. This is a galaxy in which, to choose just a few recent examples, the Soviet space program is lauded for its “diversity”; the doxxing of teenagers in the name of justice is condoned; and the worst caste systems in human history includes the United States alongside Nazi Germany.

Even now, I am confident that most people at The Times do not hold these views. Yet they are cowed by those who do. Why? Perhaps because they believe the ultimate goal is righteous. Perhaps because they believe that they will be granted protection if they nod along as the coin of our realm—language—is degraded in service to an ever-shifting laundry list of right causes. Perhaps because there are millions of unemployed people in this country and they feel lucky to have a job in a contracting industry. 

Or perhaps it is because they know that, nowadays, standing up for principle at the paper does not win plaudits. It puts a target on your back. Too wise to post on Slack, they write to me privately about the “new McCarthyism” that has taken root at the paper of record.

All this bodes ill, especially for independent-minded young writers and editors paying close attention to what they’ll have to do to advance in their careers. Rule One: Speak your mind at your own peril. Rule Two: Never risk commissioning a story that goes against the narrative. Rule Three: Never believe an editor or publisher who urges you to go against the grain. Eventually, the publisher will cave to the mob, the editor will get fired or reassigned, and you’ll be hung out to dry.

For these young writers and editors, there is one consolation. As places like The Times and other once-great journalistic institutions betray their standards and lose sight of their principles, Americans still hunger for news that is accurate, opinions that are vital, and debate that is sincere. I hear from these people every day. “An independent press is not a liberal ideal or a progressive ideal or a democratic ideal. It’s an American ideal,” you said a few years ago. I couldn’t agree more. America is a great country that deserves a great newspaper. 

None of this means that some of the most talented journalists in the world don’t still labor for this newspaper. They do, which is what makes the illiberal environment especially heartbreaking. I will be, as ever, a dedicated reader of their work. But I can no longer do the work that you brought me here to do—the work that Adolph Ochs described in that famous 1896 statement: “to make of the columns of The New York Times a forum for the consideration of all questions of public importance, and to that end to invite intelligent discussion from all shades of opinion.”

Ochs’s idea is one of the best I’ve encountered. And I’ve always comforted myself with the notion that the best ideas win out. But ideas cannot win on their own. They need a voice. They need a hearing. Above all, they must be backed by people willing to live by them. 

Sincerely,

Bari

Sunday, 20 September 2020

Make recyled plastic valuable


What is a circular economy?

A circular economy is restorative and regenerative by design. This means that materials constantly flow around a ‘closed-loop’ system, rather than being used once and then discarded. As a result, the value of materials, including plastics, is not lost by being thrown away.



What Unilever says about plastics



https://www.unilever.com/sustainable-living/reducing-environmental-impact/waste-and-packaging/rethinking-plastic-packaging/


Not perfect, but... 


By 2025, they will:


  • Halve the amount of virgin plastic we use in our packaging and an absolute reduction of more than 100,000 tonnes in plastic use
  • Help collect and process more plastic packaging than we sell
  • Ensure that 100% of our plastic packaging is designed to be fully reusable, recyclable or compostable
  • Increase the use of post-consumer recycled plastic material in our packaging to at least 25%.

This includes targets to reduce the weight of our packaging by one-third by the end of 2020 and halve the waste associated with the disposal of our products by the end of 2020. Since 2010, our waste impact per consumer use has reduced by 32%.


Sunlight dishwash bottle. We’re helping to create a circular economy for plastic packaging in many countries, particularly those where the infrastructure for collection and processing isn’t yet widespread or co-ordinated.

How our plastic commitments are driving change – an overview

1. Reduce our virgin plastic packaging by 50% by 2025, with one-third coming from an absolute plastic reduction

For example, our Seventh Generation brand is eliminating virgin petroleum (new plastic made from oil) and virgin fibre (virgin wood pulp) from its packs by using 100% post-consumer recycled (PCR) materials. Hellmann’s has switched to 100% PCR plastic bottles and jars in the US and Canada, cutting our virgin plastic use each year by 13,000 tonnes and 1,000 tonnes respectively. And our Dove brand launched several long-term initiatives in 2019, which will cut more than 20,500 tonnes of virgin plastic from its portfolio each year.

2. Help collect and process more plastic packaging than we sell by 2025

We'll help collect and process around 600,000 tonnes of material annually by 2025. We're making direct investments and partnerships in waste collection and processing, building capacity by buying recycled plastics, and through participating in extended producer responsibility schemes in which we directly pay for the collection of our packaging. For example, our Unilever Indonesia Foundation has already helped communities in 18 cities to develop systems where they can collect and sell inorganic waste. Since 2012, the waste banks have collected a total of 17,893 tonnes of packaging waste, worth 23.44 billion IDR.

3. Ensure that 100% of our plastic packaging is designed to be fully reusable, recyclable or compostable

This is a key part of embedding circular thinking – and we're making progress. In Chile, for example, we have moved from using a non-recyclable folding carton across three detergent brands – Omo, Drive and Rinso – to a 100% polyethylene (HDPE) bag which is recyclable, saving 1,634 tonnes a year. And in South Africa, all bottles of our Sunlight dishwashing liquid are recyclable, but in 2019 the 750 ml and 400 ml packs became the first to be made using 100% recycled plastic.

4. Increase the use of post-consumer recycled plastic content in our packaging to at least 25%

In 2019, we estimate that we used around 35,000 tonnes of post-consumer recycled (PCR) plastic in our packaging, such as high-density polyethylene (HDPE) and polyethylene terephthalate (PET) in our plastic bottles. We expect our use of PCR materials to accelerate rapidly over the next few years as the design processes begin to deliver at scale.

We've taken some big steps forward. For example, in 2019, Dove switched to new 100% recycled plastic bottles – where technically feasible – in North America and Europe. Our Bango sweet soy sauce brand in Indonesia began to switch to 100% recyclable polyethylene terephthalate (PET) bottles. This builds on our work in 2018, when we launched our REN Clean Skincare packaging with 100% recycled PET (rPET) bottles, working with TerraCycle, a US recycling company, to create the bottles from 80% recycled plastic bottles and 20% reclaimed ocean plastic.