Science & Technology

The Science Dispatches (08/07/18): Signs positive on new HIV vaccine. How spiders use electric fields to ‘fly’

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The Scisco science dispatches for the first week in July 2018, including promising signs for a revolutionary new HIV vaccine and how ‘ballooning’ spiders use electromagnetic fields to ‘fly’ to new horizons.

Researchers cautiously pleased with results of HIV vaccine trial

Trials of a new HIV vaccine have led to cautious optimism amongst researchers after the results were published in The Lancet this week. The study followed the progress of 393 subjects selected from 12 HIV clinics across the world including East and South Africa, India and the US.

The test subjects, HIV negative and aged between 18 and 50, were divided into eight groups, the subjects in seven of these groups received the new vaccine whilst subjects in the eighth group received a placebo.  All the subjects who received the vaccine began to show signs of an immune response to the virus.

It’s currently estimated that 37 million people worldwide are living with HIV or AIDS, with two million of the affected being children. In addition to this, the United Nation’s UNAIDS initiative estimates there are a further 1.8 million new cases each year.

Whilst HIV treatments are steadily improving and the life expectancy and life quality of sufferers have also improved over the past three decades, the virus has proved extremely difficult for scientists to deal with effectively. This is because HIV has a multitude of different strains and the virus itself mutates to avoid attack from the immune system. Treatments exist that can prevent the spread of HIV, but they must be taken every day, unlike a vaccine which can be taken just once.

Previous attempts at creating HIV vaccines have concentrated on one particular strain or another, all of which are found in different geographical locations. This new vaccine is different. It is what is known as a ‘mosaic’ vaccine as it is made up of different parts of different strains of the virus. Researchers hope that this approach could help protect against multiple strains across the World.

A companion study involving 72 rhesus monkeys was carried out in conjunction with the human trial.  The aim of this side-study was to assess if the vaccine that showed the most promise in the human trials could increase resistance against the simian-human immunodeficiency virus, a disease similar to HIV that affects monkeys. The researchers found the mosaic vaccine to be effective in 67% of cases.

A second trial will now begin involving 2,600 women in sub-Saharan Africa.

Despite these positive results, the medical community and the researchers involved in both studies urge caution. As Dr Dan H Barouch, a principal investigator on the study and a professor at Harvard Medical School told CNN “I would say that we are pleased with these data so far, but we have to interpret the data cautiously,” He continued “We have to acknowledge that developing an HIV vaccine is an unprecedented challenge, and we will not know for sure whether this vaccine will protect humans.”

New research reveals how spiders ‘fly’

 

Arachnophobes may want to grab an umbrella after reading the findings of Dr Erica Morley a biophysicist at Bristol Unversity, and her team. They investigated the phenomena of ‘ballooning’ used by species of spiders to travel great distances and found, in a remarkable turn, that the arachnids may be using the Earth’s natural electric fields and nets of gossamer to reach great heights.

The phenomenon of ‘ballooning’ amongst spiders has been observed for some time, most famously by Charles Darwin during his voyage on the Beagle.  Darwin was delighted when hundreds of tiny spiders descended on to the deck of the Beagle in 1832, speculating that these tiny creatures must have travelled distances of at least 60 miles to reach the ship.

In more recent times scientists have recorded spiders travelling distances of hundreds of miles and reaching altitudes of up to two miles.

Biologists have remained divided on just how spiders achieve such feats, some speculate that ballooning is achieved by the wind catching threads created at the abdomen of the spider. Others believe the mechanism behind the phenomenon is more complicated with spiders utilising these strands tendency to become electrostatically charged, thus allowing spiders to ride electromagnetic fields.

To test this latter hypothesis, Morley and her team introduced spiders captured in a local field to a polycarbonate box, which acted as a Faraday cage isolating them from external electric fields. This allowed Morley to control the atmosphere within the box recreating the kinds of electric fields in nature, but with the added advantage that she could end such fields quite abruptly.

Morley found that when the electric field has active, the spiders took flight from a small cardboard ramp created in the centre of their makeshift habitat. When the field was switched off, however, the spiders made very few attempts to become airborne.

Ingeniously, Morley found that the spiders’ flight could be manipulated by altering the electric field, this included changing the altitude that they were able to reach. When they take off, you can switch off the electric field and watch them drop, then switch it on and see them rise again,” she said.

What was also clear from the study, was wind is likely not a factor in Spiders’ ballooning ability as there was simply not enough air flow with the habitat available for them to become aloft.

Electron microscope scan of the hair on spiders’ legs which also allow them to detect changes in air pressure

In research conducted alongside this study, Morley and Daniel Robert, a sensory biologist also based at the Unversity of Bristol, used laser light to observe how spiders may sense electromagnetic fields. They found that trichobothria, the tiny hairs on spiders’ legs reacted to exposure to laser light, indicating that this may be how they detect the presence of electromagnetic fields.

Well as the song says, he does whatever a spider can. Legendary Spider-man co-creator Steve Ditko, who passed away in June this year depicts Spidey catching some air, unlike the methods used by his namesakes (Marvel comics)

Ballooning likely confers important evolutionary advantages to the spider. In addition to allowing them to escape predators or even seek out areas with more resources. The main advantage comes from the fact that spiders are cannibalistic and hatch in huge numbers. Obviously, it is then an evolutionary advantage for offspring to be spread as widely as possible reducing the chance of siblings devouring each other.

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About

Robert is a member of the Association of British Science Writers, qualified in Physics, Mathematics and Contemporary science. As well as contributing articles on topics as diverse as quantum physics, cosmology, medical science and the environment at Scisco media, he also writes the Null Hypothesis blog which examines pseudoscience and poor science reporting in the news media.

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