Re-wiring the brain: Increased functional connectivity within primary somatosensory cortex following synchronous co-activation

AbstractThe primary somatosensory cortex shows precise topographical organisation, but can be quickly modified by alterations to sensory inputs. Temporally correlated sensory inputs to the digits can result in the merging of digit representations on the cortical surface. Underlying mechanisms driving these changes are unclear but the strengthening of intra-cortical synaptic connections via Hebbian mechanisms has been suggested. We use fMRI measures of temporal coherence to infer alterations in the relative strength of neuronal connections between digit regions 2 and 4 following 3hours of synchronous and asynchronous co-activation. Following synchronous co-activation we find a 20% increase in temporal coherence of the fMRI signal (p=0.0004). No significant change is seen following asynchronous co-activation suggesting that temporal coincidence between the two digit inputs during co-activation is driving this coherence change. In line with previous work we also find a trend towards reduced separation of the digit representations following synchronous co-activation and significantly increased separation for the asynchronous case. Increased coherence is significantly correlated with reduced digit separation for the synchronous case. This study shows that passive synchronous stimulation to the digits strengthens the underlying cortical connections between the digit regions in only a few hours, and that this mechanism may be related to topographical re-organisation

Why is Water so Efficient at Suppressing the Effects of Explosions?

When most experienced explosives engineers first observe an explosion suppressed by bags of water, they are convinced that there has been a misfire. Depending on the amount of water and the way it is contained, the overpressure can be reduced by a factor of ten, sometimes more than twenty. The number of fragments from shell cases can be one hundred times less. Their velocities can be seven times. Slugs from focal point charges are stopped. Safety distances around magazines can be cut. The number of people evacuated from a bomb disposal site can be reduced. In June 1999, engineers from 33 Regiment (Explosive Ordnance Disposal) saved an entire village in Kosovo from the detonation of a 2,000-pound NATO bomb by using water bags

Routine versus As-Needed Bevacizumab with 12-Weekly Assessment Intervals for Neovascular Age-Related Macular Degeneration 92-Week Results of the GMAN Trial

PurposeTo evaluate the efficacy and safety of intravitreal bevacizumab (Avastin; Genentech, South San Francisco, CA) in patients with neovascular age-related macular degeneration (nAMD) using 2 different treatment regimens in which patients were assessed clinically at up to 12-week intervals.DesignRandomized, controlled, noninferiority trial.ParticipantsA total of 331 patients with nAMD.MethodsPatients were treated with 1.25 mg intravitreal bevacizumab and followed up to 92 weeks. They were randomized into 2 arms. All patients received 3 loading doses 4 weeks apart and thereafter were assessed every 12 weeks until the end of the study. One arm received a routine treatment at each 12-week assessment, and the other arm was treated at these assessments on an as-needed basis. After the loading doses, patients in either arm who showed signs of disease activity had an additional assessment after 6 weeks and at that visit had top-up treatments on an as-needed basis.Main Outcome MeasuresMean best-corrected visual acuity (BCVA) at 92 weeks.ResultsAt 92 weeks, patients who had treatments every 12 weeks had superior BCVA to those treated on an as-needed basis every 12 weeks (P = 0.008), with the regular treatment arm gaining a mean BCVA of 5.5 letters and the as-needed treatment arm gaining 0.6 letters. The regular treatment arm of the study showed significantly improved outcomes with respect to 5-, 10-, and 15-letter changes in BCVA from baseline compared with the as-needed treatment arm, as well as superior reading speed. In patients who completed the study, up to but not including week 92, the mean number of treatments was 10.8 for the regular treatment arm and 9.1 for the as-needed treatment arm.ConclusionsA treatment regimen with regular bevacizumab injections every 12 weeks after loading doses supplemented with as-needed top-up treatments produced a stable improvement in BCVA from baseline. The improvement in BCVA was broadly similar to that obtained in other studies using anti-vascular endothelial growth factor drugs with more frequent assessments and treatments

The Longevity of Behaviour Change: A Case Study of the London 2012 Olympic and Paralympic Games

Travel behaviour change is traditionally regarded as being difficult to achieve, with strategies and initiatives often generating only slow and incremental shifts in behaviour amongst the population. There is an emerging discussion in the literature that more radical approaches to travel behaviour change are needed, to contribute to achieving challenging decarbonisation targets. If a step change is required then one potential source of learning is the study of disruptions to systems of mobility provision, which may provide valuable insights into how more radical travel behaviour change is achieved and, potentially, sustained. This thesis provides an innovative approach to examining major-event disruption, in this case arising from the London 2012 Olympic and Paralympic Games, to understand the potential for change from such large, disruptive events. A four-wave longitudinal panel survey was applied to establish the extent, and longevity, of change in response to the Games. The research uses the Transtheoretical Model (TTM) to critically examine travel behaviour. The results show that change was extensive during the Games (54% made at least one change); however change was not often sustained afterwards. Reducing, relocating and re-timing were the most common changes. The key elements of the TTM were not well suited to studying change in such a context, however less commonly used constructs of the model contributed to the identification of four clusters within the sample that provided valuable insight into the behaviour observed. This research makes a valuable contribution to the growing literature around the potential for learning, and opportunities for change, when there is an imperative to do so. Whilst the longevity of changes to travel were limited, the research provided greater understanding of the adaptability and planning involved in response to major-event disruption, and what this means for future travel planning. The clusters generated helped to show the psychological constructs important for supporting different types of change, which can contribute to approaching and understanding travel behaviour change in broader contexts, when there is an imperative to change