Long-Term Effects of Serial Anodal tDCS on Motion Perception in Subjects with Occipital Stroke Measured in the Unaffected Visual Hemifield

Transcranial direct current stimulation (tDCS) is a novel neuromodulatory tool that has seen early transition to clinical trials, although the high variability of these findings necessitates further studies in clincally-relevant populations. The majority of evidence into effects of repeated tDCS is based on research in the human motor system, but it is unclear whether the long-term effects of serial tDCS are motor-specific or transferable to other brain areas. This study aimed to examine whether serial anodal tDCS over the visual cortex can exogenously induce long-term neuroplastic changes in the visual cortex. However, when the visual cortex is affected by a cortical lesion, up-regulated endogenous neuroplastic adaptation processes may alter the susceptibility to tDCS. To this end, motion perception was investigated in the unaffected hemifield of subjects with unilateral visual cortex lesions. Twelve subjects with occipital ischaemic lesions participated in a within-subject, sham-controlled, double-blind study. MRI-registered sham or anodal tDCS (1.5 mA, 20 minutes) was applied on five consecutive days over the visual cortex. Motion perception was tested before and after stimulation sessions and at 14- and 28-day follow-up. After a 16-day interval an identical study block with the other stimulation condition (anodal or sham tDCS) followed. Serial anodal tDCS over the visual cortex resulted in an improvement in motion perception, a function attributed to MT/V5. This effect was still measurable at 14- and 28-day follow-up measurements. Thus, this may represent evidence for long-term tDCS-induced plasticity and has implications for the design of studies examining the time course of tDCS effects in both the visual and motor systems

Cardiovascular magnetic resonance activity in the United Kingdom: a survey on behalf of the british society of cardiovascular magnetic resonance

<p>Background: The indications, complexity and capabilities of cardiovascular magnetic resonance (CMR) have rapidly expanded. Whether actual service provision and training have developed in parallel is unknown.</p> <p>Methods: We undertook a systematic telephone and postal survey of all public hospitals on behalf of the British Society of Cardiovascular Magnetic Resonance to identify all CMR providers within the United Kingdom.</p> <p>Results: Of the 60 CMR centres identified, 88% responded to a detailed questionnaire. Services are led by cardiologists and radiologists in equal proportion, though the majority of current trainees are cardiologists. The mean number of CMR scans performed annually per centre increased by 44% over two years. This trend was consistent across centres of different scanning volumes. The commonest indication for CMR was assessment of heart failure and cardiomyopathy (39%), followed by coronary artery disease and congenital heart disease. There was striking geographical variation in CMR availability, numbers of scans performed, and distribution of trainees. Centres without on site scanning capability refer very few patients for CMR. Just over half of centres had a formal training programme, and few performed regular audit.</p> <p>Conclusion: The number of CMR scans performed in the UK has increased dramatically in just two years. Trainees are mainly located in large volume centres and enrolled in cardiology as opposed to radiology training programmes.</p&gt

Towards virtual machine energy-aware cost prediction in clouds

Pricing mechanisms employed by different service providers significantly influence the role of cloud computing within the IT industry. With the increasing cost of electricity, Cloud providers consider power consumption as one of the major cost factors to be maintained within their infrastructures. Consequently, modelling a new pricing mechanism that allow Cloud providers to determine the potential cost of resource usage and power consumption has attracted the attention of many researchers. Furthermore, predicting the future cost of Cloud services can help the service providers to offer the suitable services to the customers that meet their requirements. This paper introduces an Energy-Aware Cost Prediction Framework to estimate the total cost of Virtual Machines (VMs) by considering the resource usage and power consumption. The VMs’ workload is firstly predicted based on an Autoregressive Integrated Moving Average (ARIMA) model. The power consumption is then predicted using regression models. The comparison between the predicted and actual results obtained in a real Cloud testbed shows that this framework is capable of predicting the workload, power consumption and total cost for different VMs with good prediction accuracy, e.g. with 0.06 absolute percentage error for the predicted total cost of the VM

First estimates of fine root production in tropical peat swamp and terra firme forests of the central Congo Basin

Tropical peatlands are carbon-dense ecosystems because they accumulate partially-decomposed plant material. A substantial fraction of this organic matter may derive from fine root production (FRP). However, few FRP estimates exist for tropical peatlands, with none from the world's largest peatland complex in the central Congo Basin. Here we report on FRP using repeat photographs of roots from in situ transparent tubes (minirhizotrons), measured to 1 m depth over three one-month periods (spanning dry to wet seasons), in a palm-dominated peat swamp forest, a hardwood-dominated peat swamp forest, and a terra firme forest. We find FRP of 2.6 ± 0.3 Mg C ha-1 yr-1, 1.9 ± 0.5 Mg C ha-1 yr-1, and 1.7 ± 0.1 Mg C ha-1 yr-1 in the three ecosystem types respectively (mean ± standard error; no significant ecosystem type differences). These estimates fall within the published FRP range worldwide. Furthermore, our hardwood peat swamp estimate is similar to the only other FRP study in tropical peatlands, also hardwood-dominated, from Micronesia. We also found that FRP decreased with depth and was the highest during the dry season. Overall, we show that minirhizotrons can be used as a low-disturbance method to estimate FRP in tropical forests and peatlands

<i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis

Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops

Intravenous sodium nitrite in acute ST-elevation myocardial infarction: a randomized controlled trial (NIAMI).

AIM: Despite prompt revascularization of acute myocardial infarction (AMI), substantial myocardial injury may occur, in part a consequence of ischaemia reperfusion injury (IRI). There has been considerable interest in therapies that may reduce IRI. In experimental models of AMI, sodium nitrite substantially reduces IRI. In this double-blind randomized placebo controlled parallel-group trial, we investigated the effects of sodium nitrite administered immediately prior to reperfusion in patients with acute ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: A total of 229 patients presenting with acute STEMI were randomized to receive either an i.v. infusion of 70 μmol sodium nitrite (n = 118) or matching placebo (n = 111) over 5 min immediately before primary percutaneous intervention (PPCI). Patients underwent cardiac magnetic resonance imaging (CMR) at 6-8 days and at 6 months and serial blood sampling was performed over 72 h for the measurement of plasma creatine kinase (CK) and Troponin I. Myocardial infarct size (extent of late gadolinium enhancement at 6-8 days by CMR-the primary endpoint) did not differ between nitrite and placebo groups after adjustment for area at risk, diabetes status, and centre (effect size -0.7% 95% CI: -2.2%, +0.7%; P = 0.34). There were no significant differences in any of the secondary endpoints, including plasma troponin I and CK area under the curve, left ventricular volumes (LV), and ejection fraction (EF) measured at 6-8 days and at 6 months and final infarct size (FIS) measured at 6 months. CONCLUSIONS: Sodium nitrite administered intravenously immediately prior to reperfusion in patients with acute STEMI does not reduce infarct size

Current knowledge on the Cuvette Centrale peatland complex and future research directions

CongoPeat Early Careers Researchers Group is a group of early career researchers who work directly or in partnership with the NERC funded CongoPeat project (NERC reference no.: NE/R016860/1; https://congopeat.net), which has provided the authors with full or partial financial and academic support.The Cuvette Centrale is the largest tropical peatland complex in the world, covering approximately 145,000 km2 across the Republic of Congo and the Democratic Republic of Congo. It stores ca. 30.6 Pg C, the equivalent of three years of global carbon dioxide emissions and is now the first trans-national Ramsar site. Despite its size and importance as a global carbon store, relatively little is known about key aspects of its ecology and history, including its formation, the scale of greenhouse gas flows, its biodiversity and its history of human activity. Here, we synthesise available knowledge on the Cuvette Centrale, identifying key areas for further research. Finally, we review the potential of mathematical models to assess future trajectories for the peatlands in terms of the potential impacts of resource extraction or climate change.Publisher PDFPeer reviewe

Changes in vegetation and soil characteristics in coastal sand dunes along a gradient of atmospheric nitrogen deposition

A field survey was conducted to detect signals of atmospheric nitrogen (N) in 11 dune systems along a nitrogen deposition gradient in the United Kingdom. In the mobile and semi-fixed dunes, above-ground biomass was positively related to N inputs. This increase was largely due to increased height and cover of Ammophila arenaria. In the long term, this increased biomass may lead to increased organic matter accumulation and consequently accelerated soil development. In the fixed dunes, above ground biomass also showed a positive relationship with N inputs as did soil C : N ratio while soil available N was negatively related to N inputs. Plant species richness was negatively related to N inputs. In the dune slacks, while soil and bulk vegetation parameters showed no relationship with N inputs, cover of Carex arenaria and Hypochaeris radicata increased. Site mean Ellenberg N numbers showed no relationship with N deposition either within habitats or across the whole dataset. Neither abundance-weighting nor inclusion of the Siebel numbers for bryophytes improved the relationship. The survey reveals that the relationships of soil and vegetation with atmospheric N deposition vary between sand dune habitats but, despite this variability, clear correlations with N inputs exist. While this survey cannot establish causality, on the basis of the relationships observed we suggest a critical load range of 10 - 20 kg N ha(-1) yr(-1) for coastal sand dunes in the UK

Tropical peatlands and their conservation are important in the context of COVID-19 and potential future (zoonotic) disease pandemics.

The COVID-19 pandemic has caused global disruption, with the emergence of this and other pandemics having been linked to habitat encroachment and/or wildlife exploitation. High impacts of COVID-19 are apparent in some countries with large tropical peatland areas, some of which are relatively poorly resourced to tackle disease pandemics. Despite this, no previous investigation has considered tropical peatlands in the context of emerging infectious diseases (EIDs). Here, we review: (i) the potential for future EIDs arising from tropical peatlands; (ii) potential threats to tropical peatland conservation and local communities from COVID-19; and (iii) potential steps to help mitigate these risks. We find that high biodiversity in tropical peat-swamp forests, including presence of many potential vertebrate and invertebrate vectors, combined, in places, with high levels of habitat disruption and wildlife harvesting represent suitable conditions for potential zoonotic EID (re-)emergence. Although impossible to predict precisely, we identify numerous potential threats to tropical peatland conservation and local communities from the COVID-19 pandemic. This includes impacts on public health, with the potential for haze pollution from peatland fires to increase COVID-19 susceptibility a noted concern; and on local economies, livelihoods and food security, where impacts will likely be greater in remote communities with limited/no medical facilities that depend heavily on external trade. Research, training, education, conservation and restoration activities are also being affected, particularly those involving physical groupings and international travel, some of which may result in increased habitat encroachment, wildlife harvesting or fire, and may therefore precipitate longer-term negative impacts, including those relating to disease pandemics. We conclude that sustainable management of tropical peatlands and their wildlife is important for mitigating impacts of the COVID-19 pandemic, and reducing the potential for future zoonotic EID emergence and severity, thus strengthening arguments for their conservation and restoration. To support this, we list seven specific recommendations relating to sustainable management of tropical peatlands in the context of COVID-19/disease pandemics, plus mitigating the current impacts of COVID-19 and reducing potential future zoonotic EID risk in these localities. Our discussion and many of the issues raised should also be relevant for non-tropical peatland areas and in relation to other (pandemic-related) sudden socio-economic shocks that may occur in future