A study published today by Dr Beth Mortimer and colleagues at the Department of Zoology and University Carlos III of Madrid reveals that orb weaving spiders can compare 3D vibrational inputs into their 8 legs from the web to locate prey.
Watch a spider catch its prey:
Dr Mortimer found that as vibrations spread from prey through a spider’s orb web, the information on prey location becomes available by comparing 3D motion across the spiders’ eight legs.
Using computer models of orb webs, the researchers investigated whether web vibration contains information on the location of a vibration source for spiders that directly and remotely monitor web vibration.
They found that comparisons of 3D vibration magnitude across eight legs (direct monitoring) allowed them to determine vibration source distance and direction, which was not possible with a remote monitoring strategy.
The researchers concluded that specific web features which are under the control of spiders that promote the transfer of localisation information.
Read the full paper: ‘Decoding the locational information in the orb web vibrations of Araneus diadematus and Zygiella x-notata’ in Journal of the Royal Society Interface
Until September BBC Gardeners’ World magazine is running a monthly feature ‘Grow Yourself Healthy’. The May issue focuses on how gardens and gardening can improve sleep, and featured Julie Darbyshire, researcher for the University of Oxford Critical Care Research Group (Nuffield Department of Clinical Neurosciences), alongside other sleep researchers and experts, discussing the benefits of gardening ahead of the RHS flagship flower show in Chelsea.
If you’re not tired, you’re not going to fall asleep. It is perhaps obvious when you think about it, but many of us don’t. We all know we should have 30 minutes of exercise every day but with today’s hectic lifestyle many of us struggle to find the time. Thankfully, for the gym-phobic amongst us with memories of wet and cold cross-country days across the muddy school playing field, exercise needn’t be always about running, or going to the gym. Ever tried digging over a flower bed or veg plot? Gardening can be a great way to achieve an all-body workout. It can also be a low-impact path to being a little bit more active. Some gentle pottering in the garden (beneficial in itself) can lead to other tasks, which leads to more physical exertion, which can only ever be a good thing... But physical exercise is not the only way that gardening can help you sleep at night.
Sleep is hugely influenced by your natural circadian rhythm. Every cell in the human body has a clock that’s controlled by the suprachiasmatic nucleus (SCN) in the brain. The SCN is linked directly to the eyes. Light then, is a key driver to circadian control. Research has demonstrated if you put people into dark places with no external clues to the time of day, their circadian rhythms will become abnormal very quickly. The body needs appropriate exposure to daylight to regulate the body’s responses to help ‘reset’ this clock and keep you “on time”. Many of us spend the majority of the day inside. Light levels in an office, even close to a window, will be far below those of bright natural daylight which is around 20,000 lux. The spectrum of light inside is also quite different. Natural daylight is quite ‘blue’ (5000-6500K) and the body expects a change to more orange/red tones as the day fades to night. This is one of the reasons why ‘screen time’ in the evening isn’t good when you are supposed to be preparing for sleep. The light entering the eyes is too blue for the time of day. Spending the majority of the day inside where light levels are both low (lux levels around 150 are not uncommon) and often in the ‘warmer’ spectrum range (<3000K) is biologically confusing. Getting outside, getting a bit out of breath, and even being a bit chilly, are the best ways to regulate your body clock.
The Critical Care Research Group at the University of Oxford has been exploring how the hospital environment influences the patients’ experiences of their admission. As part of a research project (SILENCE) that was funded by the National Institute of Health Research (Research for Patient Benefit, ref: PB-PG-0613-31034), the group has been studying sleep patterns in patients admitted to the intensive care unit (ICU). The results of the SILENCE sleep study have been published in the Journal of the Intensive Care Society. Julie Darbyshire, lead researcher on the project, was also interviewed about the study for a critical care focused podcast series.
The research team used several different ways to electronically measure sleep and also asked patients and their nurses who were looking after them overnight to complete a questionnaire. All methods of sleep measurement confirmed that sleep was poor. Most patients were able to sleep for at least some of the time but the average total sleep overnight was just over two hours. This is a long way short of the seven to eight hours sleep that is recommended for most adults. The team also found that the average time a patient in the ICU can expect to be asleep before awakening is just one minute. This can leave patients exhausted by the end of the night and many feel that they haven’t slept at all.
Professor Duncan Young, senior clinical lead for the Critical Care Research Group and honorary NHS consultant in anaesthetics and intensive care medicine, said: ‘Patients clearly struggle to sleep well when in intensive care. Sleep deprivation likely leads to confusion, and confusion is thought to complicate the healing process and slow recovery. The real challenge is knowing what to do to improve things for patients.’
Julie says: ‘Patients may be offered earplugs and eye masks to help them sleep, but not everyone likes wearing them. Improving the environment has to be the better approach. This should include reducing sound levels, making sure that patients have access to plenty of natural light during the day, and turning lights off overnight.'
Julie also suggests that having access to the outside is likely to benefit patients recovering from their critical illness. Early hospital environment work by Robert Ulrich in the 1980s showed that patients who could see trees outside went home sooner and experienced lower levels of pain than those patients who could only see a wall. More recent studies suggest that access to a garden during a hospital stay can lower stress levels in both patients and their families. Recognising this, Horatio’s Garden is a charity that creates and builds accessible gardens for NHS spinal injury units and a number of hospitals around the UK have gardens where they can take their ICU patients during the day.
The team in Oxford has been able to show how different sleep in the ICU is when compared to normal healthy adult sleep patterns. As well as being awake for much of the night, patients in the ICU experience almost no rapid eye movement (REM) sleep, or deeper, restful sleep. This means that even when patients do sleep in the intensive care unit, their sleep is poor quality. Healthy sleep would include about 20% of REM sleep and about 20% of deep sleep. Good quality sleep is vital for preservation of the immune function, recovery, and can help prevent delirium which is a common problem for patients in the intensive care unit. Persistent poor sleep may also lead to longer-term cognitive and mental health problems. It has recently been reported that patients struggling to cope mentally after their critical illness can also experience worsening physical health .
Gardening is, in and of itself, a positive, forward-looking activity. After all, no-one plants carrot seeds without expecting to eat carrots in the future! The Kings Fund report on Gardens and Health (2016) highlights some of the mental health benefits to just being in a natural environment, GPs in Scotland are working with the Royal Society for the Protection of Birds to offer ‘nature prescriptions’ in Shetland, and the Royal Horticultural Society (RHS) has teamed up with GPs across the UK as part of a new ‘social prescribing’ scheme. The University of Oxford Gardens, Libraries and Museums (GLAM) project for well-being is looking at this in more detail. Researchers from the Centre for Evidence Based Medicine (Nuffield Department of Primary Care Health Sciences) are working with GLAM to promote knowledge exchange, raise awareness, and to add to the evidence base to support wider implementation of social prescribing.
This year’s Chelsea Flower Show has a strong focus on the health benefits of interacting with nature. Many of the show gardens feature gardening for resilience, recovery, and wellbeing. So if you’re struggling to sleep at night, go outside during the day, plant some seeds, prune something, dig the borders, enjoy the fresh air and the sunshine, and reap the rewards of a good night’s sleep.
For Mental Health Awareness Week 2019, we are exploring how the University of Oxford has been researching the potential of online psychological treatments to support better mental health care.
The effects of the internet revolution over the past decade alone has been astounding. From the palm of our hand, the top of our desks and in our pockets, we have drastically altered the way we conduct our everyday lives and enhanced our capabilities.
The scale of internet use alone is evidence enough of its effects. According to the Office for National Statistics, 90% of adults in the UK reported being regular internet users and virtually all adults aged 16 to 34 reported being recent internet users (99% in 2018 compared to 44% of adults aged over 75).
Internet driven technologies have enhanced most aspects of our everyday existence, but what’s the potential for harnessing this capability for better health and care? We are seeing both national and local policies that are emphasising the need for embracing a spectrum of internet driven technologies to support professionals and patients alike.
But what about mental health? This Mental Health Awareness Week, the scale of the mental health challenge is serving as an urgent reminder as to why we should be embracing innovation in tackling it.
One in four of us at some point will face a mental health problem each year. 300,000 people leave the work place each year because of mental health issues and it accounts for 15.4 million sick days.
It presents one of the most burning social and economic issues facing the world today.
Some of the most common disorders seen by mental health professionals are Social Anxiety Disorder (SAD) and Post Traumatic Stress Disorder (PTSD). SAD normally starts in childhood or adolescence and is one of the most persistent disorders when not treated. PTSD is a common problem that can occur after a traumatic event and can lead to chronic disability and high healthcare costs if left untreated.
Both of these conditions normally respond well to psychological interventions such as cognitive behavioural therapies (CBT). Specific CBT interventions for these problems were developed by researchers at the University of Oxford at the Oxford Centre for Anxiety Disorders and Trauma (OxCADAT). These treatments are now widely used within the NHS and beyond, and are recommended by the National Institute for Health and Care Excellence (NICE).
While CBT can effectively treat these two common conditions, like any medical intervention, it comes with its own unique set of challenges. Common across mental health services, patients can face difficulties in accessing treatment given the high demand and limited number of therapists.
In the light of these problems and the scale of internet use, one potential solution that is receiving attention here at the University of Oxford is the use of internet-based versions of effective psychological therapies that have traditionally been delivered face-to-face.
OxCADAT have been investigating therapist-guided, internet-based forms of their previously developed CBT programmes for SAD and PTSD and assessing their effectiveness and potential.
The early research has shown some promising results.
The clinical outcomes of these early studies have suggested that internet-delivered CBT may be just as effective as face-to-face therapy sessions. Crucially, good outcomes have been achieved with a drastically reduced workload for the therapists compared to face-to-face clinical settings: 20% for SAD and 25% for PTSD treatment.
As well as being less resource intensive, the early results have indicated that patients may find online-delivered therapies just as acceptable as traditional face-to-face therapies. The early pilots have shown that patients reported greater control over their treatment and greater convenience when undertaking therapy online. In patients suffering with common mental health disorders, this has the potential to attract a greater number of people seeking treatment.
Therapy for common mental health disorders going online has the potential to transform and improve the mental health treatment offering. There could be reduced waiting lists, greater successful turnover of patients, more patients being able to access treatment even if they cannot attend face-to-face therapy and a reduction in the societal and economic burden of mental health problems.
What the key focus is now here at Oxford is examining these treatments further and building the evidence base. Oxford has been a world leader in the development of face-to-face psychological therapies, which are now mainstream throughout the NHS. It is hoped that online CBT can reach the same level of success.
Furthermore, there is also ongoing research adapting internet therapies for global use. Online solutions to these conditions could make a big difference to the global mental health crisis, if we can find effective methods to transport and adapt these programmes for use around the world.
Although these are early days, the results are indeed encouraging. If further research is just as promising, Oxford would be building on its proud legacy in leading some of the greatest evolutions in mental health treatment.
In a series of videos launching The Mathematical Observer, a new YouTube channel showcasing the research performed in the Oxford Mathematics Observatory, Oxford Mathematician Michael Gomez (in collaboration with Derek Moulton and Dominic Vella) investigates the science behind the jumping popper toy.
Snap-through buckling is a type of instability in which an elastic object rapidly jumps from one state to another. Such instabilities are familiar from everyday life: you have probably been soaked by an umbrella flipping upwards in high winds, while snap-through is harnessed to generate fast motions in applications ranging from soft robotics to artificial heart valves. In biology, snap-through has long been exploited to convert energy stored slowly into explosive movements: both the leaf of the Venus flytrap and the beak of the hummingbird snap-through to catch prey unawares.
Despite the ubiquity of snap-through in nature and engineering, how fast snap-through occurs (i.e. its dynamics) is generally not well understood, with many instances reported of delay phenomena in which snap-through occurs extremely slowly. A striking example is a children’s ‘jumping popper’ toy, which resembles a rubber spherical cap that can be turned inside-out. The inside-out shape remains stable while the cap is held at its edges, but leaving the popper on a surface causes it to snap back to its natural shape and leap upwards. The snap back is not immediate: a time delay is observed during which the popper moves very slowly before rapidly accelerating.
The delay can be several tens of seconds in duration — much slower than the millisecond or so that would be expected for an elastic instability. Playing around further reveals other unusual features: holding the popper toy for longer before placing it down generally causes a slower snap-back, and the amount of delay is highly unpredictable, varying greatly with each attempt.
By Shamit Shrivastava and Robin Cleveland
Ultrasound has long been an important tool for medical imaging. Recently, medical researchers have demonstrated that focused ultrasound waves can also improve the delivery of therapeutic agents such as drugs and genetic material. The waves form bubbles that make cell membranes - as well as synthetic membranes enclosing drug-carrying vesicles - more permeable. However, the bubble-membrane interaction is not well understood.
Soft lipid shells, insoluble in water, are a key component of the barrier that surrounds cells. They are also used as drug nanocarriers: nanometer size particles of fat or lipid molecules that carry the drug to be delivered locally at the diseased organ or location, and which can be injected inside the body.?
The lipid shell can be “popped” by soundwaves, which can be focused to a spot around the size of a grain of rice, resulting in a highly localized opening of barriers potentially overcoming major challenges in drug delivery.
However, the understanding of such interactions is very limited which is a major hurdle in biomedical applications of ultrasound. Lipid shells can melt from a gel to a fluid-like material depending on environmental conditions.
By observing the nanoscopic changes in lipid shells in real time as they are exposed to soundwaves, our research has shown that lipid shells are easiest to pop when they’re close to melting.? We also show that after rupture, a cavity forms and the lipids at the interface experience “evaporative cooling” - the same process by which sweat cools our body - which can locally freeze the lipids, or even water, at the interface.? This research advances the fundamental understanding of the interaction of sound waves and lipid shells with applications in drug delivery.
We performed ultrasound experiments on an aqueous solution containing a variety of lipid membranes, which are similar to cellular membranes. We tagged the membranes with fluorescent markers whose light emission provided information about the molecular ordering within the membranes. We then fired ultrasound pulses into the solution and watched for bubbles. The bubbles began to form at lower acoustic energy when the membranes were transitioning from a gel state to a more liquid-like state. The bubbles also lasted longer during this phase transition. ?
We explained these observed effects with a model that — unlike previous models — account for heat flow between the membranes and the surrounding fluid.
Future work may be able to use this model of membrane thermodynamics to optimize drug-carrying vehicles with membranes that go through a phase transition at the desired moment during an ultrasound procedure.
Read the full study - 'Thermodynamic state of the interface during acoustic cavitation in lipid suspensions' - in Physical Review Materials
Find out more about Dr Shamit Shrivastava
Find out more about Robin O. Cleveland?
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