Tag: 26/2/21

Social Cues Impacts on Human Decision-making in Emergencies

Man at the wheel of a car. Photo by why kei on Unsplash.

A study showed that, when participants in a simulated crash of an autonomous vehicle were told that others had chosen to crash into a wall to save pedestrians, their own willingness to do so went up by two-thirds.

As autonomous vehicles become more commonplace, and the need to program them for safety emerges, a better understanding of how humans react in such situations is needed. Study author Jonathan Gratch, the principal investigator for this project, and a computer scientist at the USC Institute for Creative Technologies, said that current models for humans in life-or-death situations, humans think differently to how they do in reality. There are no moral absolutes, rather ” it is more nuanced”.

Seeking to understand how humans make decisions in life-or-death situations and how to apply them to the programming of autonomous vehicles and robots, researchers presented a modified trolley problem to participants using a modified ‘trolley problem’.

The trolley problem is a classic hypothetical scenario psychologists use to investigate human decision-making. Essentially, it involves the decision to divert a tram to hit one person or to leave it on its track and hit five, and it has a number of variations. In one medical variation of the trolley problem, one person could be killed and their organs harvested to save five terminally ill patients — a choice that is overwhelmingly rejected.  

In three of four simulations presented to them, the participants had to choose whether to tell their autonomous vehicle to hit a wall, risking harm to themselves, or hit five pedestrians. The higher the likelihood of injury to pedestrians, the more likely the participants were to choose hitting the wall and risking self harm. The authors showed that in so doing, people balance the risk of injury to self against the potential of injury to others as a guideline.

In the fourth scenario, a social element was added, where participants were told that their peers had chosen to save the pedestrians. In this case, the proportion of participants electing to save the pedestrian went up from 30% to 50%.

However, Gratch there is a reverse as well: “Technically there are two forces at work. When people realize their peers don’t care, this pulls people down to selfishness. When they realize they care, this pulls them up.”

The researchers showed that using the trolley problem as a basis for decision-making is insufficient, as it fails to capture the complexity of human decision-making. The researchers also concluded that transparency in the programming of autonomous machines was important for the public, as well as human operators assuming control in the event of an emergency.

Source: News-Medical.Net

Journal information: de Melo, C. M., et al. (2021) Risk of Injury in Moral Dilemmas With Autonomous Vehicles. Frontiers in Robotics and AI. doi.org/10.3389/frobt.2020.572529.

SA Medical Aid Schemes May Not Have to Pay for Public’s Vaccines

Medical aid scheme executives have pointed out that the latest budget means that medical aid schemes may no longer need to contribute for the vaccination of the South African population without medical insurance. 

South Africa’s medical insurance schemes had been in discussions on funding at least part of the government’s vaccine rollout for uninsured members of the public.

The R9 billion allocated in the budget may be enough to cover the vaccine costs of the entire country, said executives from the two leading medical aid schemes.

About 7 million people are covered by medical aid schemes, about a quarter of the country’s population. Discovery Health, Medscheme and Momentum together administer some 80% of private sector medical aid plans.

“I think the government is looking at this and saying this is our role,” said Damian McHugh, executive head of sales and marketing at Momentum Health Solutions. He agreed with the idea that the budget figure implied that schemes may not have to help cover vaccinations for non-members, although it did not remove the discussion of subsidies.

McHugh went on to explain that the costs would depend on which vaccines were procured, and schemes would still have to contribute in case booster shots or new vaccination rounds became necessary.

However, given record additions to their reserves last year due to medical services not being taken or postponed, along with not having to contribute to the vaccination of non-members, medical aid schemes stand to reap even greater benefits.

Source: Reuters

Siemens COVID Antigen Test Kit Receives German Approval

Siemens Healthineers announced on Wednesday that their antigen self-test kit, which uses samples from a nasal swab, has received limited special approval from the Federal Office for Drugs and Medical Devices (BfArM) for self-use by laypeople in Germany. The regular conformity assessment procedure for the standardised ‘CE‘ mark was also initiated for personal use by laypeople.

“With the provision of the COVID-19 antigen rapid test for possible use by laypeople in Germany, we are breaking new ground and are thus continuing to fulfill our social responsibility to support a return to normal social life,” said Bernd Ohnesorge, Head of Europe, Middle East, and Africa Regions, Siemens Healthineers

The practicability of the kit was confirmed by a study in which 50 participants without medical training personally carried out the test by following the instructions for use. The test already has a CE mark for use by specialist groups for taking samples in the nose.

“The CLINITEST COVID-19 Antigen Self-Test offers users a high degree of flexibility in performing the test with very good quality results,” said Christoph Pedain, Head of Point of Care Diagnostics at Siemens Healthineers.

Siemens’ COVID-19 Antigen Self-Test takes 15 minutes to give a result, using samples taken from both nostrils using a swab. The swab is then washed out in a reagent, which detaches a specific protein from the surface of the virus. The resulting liquid is dripped into a recess in the test cassette.

The test liquid migrates into the field of view of the cassette within 15 minutes, becoming visible as a line. The position and number of lines indicate as to whether there is a positive or negative test result, or whether there was a problem, necessitating a repeat of the test.

In the instructions, the tester is shown the steps to achieve a test result, including instructions on how to proceed according to the test result. A negative test result does not exempt the user from any local COVID regulations. Currently, the test kit is also available in the UK.

Source: Siemens

Discovering Antibodies That Are Safe And Effective Against Zika

The Zika outbreak of 2015 and 2016 left lasting consequences for children who were in the womb when their mothers were infected with the virus, and now researchers are investigating a safe vaccine that will not negatively interact with certain other viruses.

Zika is a flavivirus, a family which includes dengue, West Nile, and yellow fever virus. In order to protect against these and other pathogens, “we have the ability to make a huge diversity of antibodies, and if we get infected or vaccinated, those antibodies recognise the pathogen,” explained first author Shannon Esswein, a graduate student at the California Institute of Technology.

However, when getting sick with a virus a second time, the body’s own immune response can worsen the situation. Known as antibody-dependent enhancement (ADE), this is when the antibodies stick to the outside of the virus but not neutralising its ability to lock onto cells. This can inadvertently help the virus to infect more cells by letting it enter cells the antibodies are sticking to. A recent study sought to investigate whether this could happen with monoclonal antibody treatments for COVID.

In order to prevent ADE when creating a vaccine, knowing how antibodies adhere to a specific virus is crucial for scientists. In the case flaviviruses, this is especially important as antibodies that protect against one flavivirus may also stick to, but not protect against other flaviviruses, raising the risk of ADE. Antibodies generated in response to a Zika virus vaccine could trigger ADE, if that person is exposed to other flaviviruses such as dengue.

To understand this, the researchers looked at a portion of the flavivirus called the envelope domain III protein, which has been shown to be an important target for protective antibodies fighting flavivirus infections. They studied how those antibodies changed over time as they matured and became better able to adhere to the Zika virus. They also looked at how the antibodies cross-reacted with other flaviviruses, including the four dengue virus types. Their results showed that the Zika antibodies also tightly stick to and defend against dengue type 1, but only weakly stick to West Nile and dengue types 2 and 4. “The weak cross-reactivity of these antibodies doesn’t seem to defend against those flaviviruses, but also doesn’t induce ADE,” Esswein said. These results suggest that the envelope domain III could be a useful basis for a safe vaccine. They also described structures demonstrating how two antibodies recognise Zika and West Nile envelope domain III.

The study results demonstrate how the body mounts “a potent immune response to Zika virus,” said Esswein. Insights gained on the antibodies involved in this immune response will aid the development of new vaccines.

Source: Medical Xpress

Journal information: Shannon R. Esswein et al. Structural basis for Zika envelope domain III recognition by a germline version of a recurrent neutralizing antibody, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.1919269117

Global COVID Recovery Needs to Address Oxygen Shortages

At the virtual launch of Global Citizen’s Recover Better Together Campaign, access to vaccines and medical resources was highlighted as a key area to address.

“Covid-19 has threatened the lives and livelihoods of everyone on the planet. To respond, we must take several urgent actions. The only way that we will be able to recover better, together is by defeating the virus everywhere through universal access of vaccines, diagnostics, and therapeutics,” said World Health Organization Director-General Dr Tedros Adhanom Ghebreyesus.

To this end, the Recover Better Together Campaign, an initiative organised by the Global Citizen, the European Commission and the WHO, aims to create momentum for global COVID pandemic recovery, with a return to the implementation of global goals.

“To fight the pandemic, we need to pool resources, capabilities, knowledge and intellectual property. That is why we continue to call on world leaders to support the COVAX facility to ensure rapid and equitable access to Covid-19 vaccines for all countries. Another important step is to enable the transfer of medical technology for the duration of the pandemic,” said President Cyril Ramaphosa.

One of key medical resource is oxygen, which is in short supply in many low- and middle-income countries, which have to provide enough for up to half a million COVID patients. WHO data shows that 1.1 million cylinders are needed daily in developing countries, with Africa seeing the biggest surge in demand. Hospitals in Nigeria have reported running out of oxygen, leading to preventable deaths.

According to the WHO, public hospitals across 41 African countries have fewer than 2000 working ventilators. In comparison, the United States has more than 170 000 ventilators. The South African private sector has about 4000 ventilators, and around 2000 in the public sector. The WHO said the launch of the Covid Tools Accelerator Therapeutics pillar, co-led by Unitaid and Wellcome, has improved access to oxygen. On 25 February the Covid-19 Oxygen Emergency Taskforce was also launched by the WHO.

Unitaid Executive Director Dr Philippe Duneton said the Taskforce now needs an additional $90 million US for delivery of oxygen in up to 20 countries including Malawi, Nigeria and Afghanistan.

“This is a global emergency that needs a truly global response, both from international organisations and donors. Many of the countries seeing this demand struggled before the pandemic to meet their daily oxygen needs,” said Duneton. “Now it’s more vital than ever that we come together to build on the work that has already been done, with a firm commitment to helping the worst-affected countries as quickly as possible.”

Source: Health-e News

Researchers Study Enzyme Processes for New Drugs

Traditional discovery has produced drugs that effectively target proteins directly involved with disease, but options are starting to run out and researchers are looking to more complex and obscure interactions for drug targets.

So far, drug discovery has used the ‘small molecule’ approach, where a specific protein is targetted in a cancer cell to shut it down and bring down the cancer cell as a whole. Up until this point, traditional drugs have only been able to target proteins that are involved in the disease that also have activities that are amenable to the small molecule approach, leaving a vast number of proteins unaddressed. Many of these other proteins may be involved in disease processes behind the scenes.

“It’s starting to get to the point where we’ve kind of taken traditional drug discovery as far as we can, and we really need something new,” explained University of Nevada, Las Vegas biochemist Gary Kleiger.

“Cancer cells are clever,” Kleiger said. “They can evolve very, very quickly. So, a drug might be working at first—targeting an enzyme and telling that enzyme, ‘stop doing your activity,’ which can stop the cancer cells from growing. Those cancer cells appear to lie dormant, but all the while there are still little things that happen that eventually enable those cancer cells to bypass that drug.” Therefore, in order to stay ahead of cancer’s capacity to evolve drug resistance, it is necessary to target many additional disease-causing proteins, and thus, limiting the landscape of druggable proteins is a serious disadvantage.

The new approach by investigated by Kleiger and collaborators uses a family of human enzymes called ubiquitin ligases found in human cells. Of about 20 000 known proteins in the human body, some 5-10% are enzymes.

Kleiger’s team uses cutting edge cryo electron microscopes that can image the ubiquitin ligases when they’re at work. To test their hypotheses, Kleiger and collaborators measure the activity of ‘mutated’ enzymes that should now be defective in their activities.

Kleiger compared the process to how a 50 000 year old society might view a bicycle. They could identify its purpose and general properties, but could test the importance of a certain gear; if it was bent, the bicycle would no longer function. “We can do that at the molecular level with the enzymes,” he said.

Source: Medical Xpress

Journal information: Daniel Horn-Ghetko et al, Ubiquitin ligation to F-box protein targets by SCF–RBR E3–E3 super-assembly, Nature (2021). DOI: 10.1038/s41586-021-03197-9