Gene expression responses to acute and chronic heat stress in the common reef-building coral Pocillopora verrucosa

Global climate change is impacting coral reefs worldwide, with approximately 19% of reefs being permanently degraded, 15% showing symptoms of imminent collapse, and 20% at risk of becoming critically affected in the next few decades. This alarming level of reef degradation is mainly due to an increase in frequency and intensity of natural and anthropogenic disturbances. Recent evidence has called into question whether corals have the capacity to acclimatize or adapt to climate changes and some groups of corals showed inherent physiological tolerance to environmental stressors. The aim of the present study was to evaluate mRNA expression patterns underlying differences in thermal tolerance in specimen of the common reef-building coral Pocillopora verrucosa collected at different locations in Bangka Island waters (North Sulawesi, Indonesia). Part of the experimental work was carried out at the CoralEye Reef Research Outpost (Bangka Island). This includes sampling of corals at selected sites and at different depths (3 and 12 m) as well as their experimental exposure to an increased water temperature under controlled conditions for 3 and 7 days. Levels of mRNAs encoding ATP synthase (ATPs) NADH dehydrogenase (NDH) and a 70kDa Heat Shock Protein (HSP70) were evaluated by quantitative real time PCR. Transcriptional profiles evaluated under field conditions suggested an adaptation to peculiar local environmental conditions in corals collected at different sites and at the low depth. Nevertheless, high–depth collected corals showed a less pronounced site-to-site separation suggesting more homogenous environmental conditions. Exposure to an elevated temperature under controlled conditions pointed out that corals adapted to the high depth are more sensitive to the effects of thermal stress, so that reacted to thermal challenge by significantly over-expressing the selected gene products. Being continuously exposed to fluctuating environmental conditions, low-depth adapted corals are more resilient to the stress stimulus, and indeed showed unaffected or down-regulated mRNA expression profiles. Overall these results highlight that transcriptional profiles of selected genes involved in cellular stress response are modulated by natural seasonal temperature changes in P. verrucosa. Moreover, specimens living in more variable habitats (low-depth) exhibit higher basal HSP70 mRNA levels, possibly enhancing physiological tolerance to environmental stressors

A Novel Thermo-Mechanical Model to Assess the Dynamic Thermal Rating of Multi-Span Overhead Transmission Lines

The power flow limits of transmission lines are set in order to ensure a given level of security to the electric system; their improper definition can reduce system reliability, increase the curtailment of renewable energy sources or create barriers to the free trading of energy.Unlike the previous literature, the Dynamic Thermal Rating procedure here proposed takes into account not only that the temperature of conductors can vary span by span for different weather conditions, but also the mechanical interaction between spans, due to their different elongation and to the consequent rotation of insulator strings.The developed tool is able to forecast the time trend of conductor temperatures, tensions, sags and clearances at each span, or to indicate which current can be carried for a given time before a clearance or temperature constraint is violated.Several case studies compares the results of this novel method with the outcomes of the traditional "ruling span" technique, especially when using High-Temperature Low-Sag (HTLS) conductors, having non-linear behaviour with respect to temperature

Group Augmentation in Realistic Visual-Search Decisions via a Hybrid Brain-Computer Interface.

Groups have increased sensing and cognition capabilities that typically allow them to make better decisions. However, factors such as communication biases and time constraints can lead to less-than-optimal group decisions. In this study, we use a hybrid Brain-Computer Interface (hBCI) to improve the performance of groups undertaking a realistic visual-search task. Our hBCI extracts neural information from EEG signals and combines it with response times to build an estimate of the decision confidence. This is used to weigh individual responses, resulting in improved group decisions. We compare the performance of hBCI-assisted groups with the performance of non-BCI groups using standard majority voting, and non-BCI groups using weighted voting based on reported decision confidence. We also investigate the impact on group performance of a computer-mediated form of communication between members. Results across three experiments suggest that the hBCI provides significant advantages over non-BCI decision methods in all cases. We also found that our form of communication increases individual error rates by almost 50% compared to non-communicating observers, which also results in worse group performance. Communication also makes reported confidence uncorrelated with the decision correctness, thereby nullifying its value in weighing votes. In summary, best decisions are achieved by hBCI-assisted, non-communicating groups

Enhancement of group perception via a collaborative brain-computer interface

Objective: We aimed at improving group performance in a challenging visual search task via a hybrid collaborative brain-computer interface (cBCI). Methods: Ten participants individually undertook a visual search task where a display was presented for 250 ms, and they had to decide whether a target was present or not. Local temporal correlation common spatial pattern (LTCCSP) was used to extract neural features from response-and stimulus-locked EEG epochs. The resulting feature vectorswere extended by including response times and features extracted from eye movements. A classifier was trained to estimate the confidence of each group member. cBCI-assisted group decisions were then obtained using a confidence-weighted majority vote. Results: Participants were combined in groups of different sizes to assess the performance of the cBCI. Results show that LTCCSP neural features, response times, and eye movement features significantly improve the accuracy of the cBCI over what we achieved with previous systems. For most group sizes, our hybrid cBCI yields group decisions that are significantly better than majority-based group decisions. Conclusion: The visual task considered here was much harder than a task we used in previous research. However, thanks to a range of technological enhancements, our cBCI has delivered a significant improvement over group decisions made by a standard majority vote. Significance: With previous cBCIs, groups may perform better than single non-BCI users. Here, cBCI-assisted groups are more accurate than identically sized non-BCI groups. This paves the way to a variety of real-world applications of cBCIs where reducing decision errors is vital

Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

Aging evaluation of high power lithium cells subjected to micro-cycles

A typical operating condition of storage batteries requires to deliver and absorb small currents in large intervals of time, in order of minutes or hours. However, in the last years lithium batteries have been more and more considered in "power oriented" applications, in which they are required to manage large currents in short intervals of time, typically a few seconds or tens of seconds. Unfortunately, very limited information about this kind of usage is available in literature, in terms of battery performance and aging. Therefore, the paper focuses firstly on the experimental evaluation of performance of high power and super high power lithium batteries also in comparison to other power oriented storage systems adequate for use onboard hybrid vehicles, such as supercapacitors (SCs). The evaluation has been performed through experimental tests. Results have shown that these batteries are able to guarantee significant performance, even higher than data declared by manufacturer, with slight over-temperature.Then, for high power lithium batteries aging is discussed, when they are subjected to shallow-depth charge/discharge cycles. The aim is to evaluate if the battery life corresponding to such micro-cycles can reach several hundreds of thousands that are required for applications such as hybrid vehicles and hybrid stationary generation systems. Also in this case experimental tests able to prove it have been executed. They have shown a substantially unaltered capacity fade during the execution of hundreds of thousands of micro-cycles, thus confirming the vocation of these devices for power-oriented applications

Brain–Computer Interfaces for Human Augmentation

Editorial for the Special Issue Brain-Computer Interfaces for Human Augmentatio

Distributed Raman optical amplification in phase coherent transfer of optical frequencies

We describe the application of Raman Optical-fiber Amplification (ROA) for the phase coherent transfer of optical frequencies in an optical fiber link. ROA uses the transmission fiber itself as a gain medium for bi-directional coherent amplification. In a test setup we evaluated the ROA in terms of on-off gain, signal-to-noise ratio, and phase noise added to the carrier. We transferred a laser frequency in a 200 km optical fiber link with an additional 16 dB fixed attenuator (equivalent to 275 km of fiber on a single span), and evaluated both co-propagating and counter-propagating amplification pump schemes, demonstrating nonlinear effects limiting the co-propagating pump configuration. The frequency at the remote end has a fractional frequency instability of 3e-19 over 1000 s with the optical fiber link noise compensation

Dietary Management in IBS Patients

Irritable bowel syndrome (IBS) is a chronic, relapsing functional disorder of the gastrointestinal tract characterized by abdominal pain, bloating, and changes in bowel habits lacking a known structural or anatomic explanation. According to the Rome IV criteria, IBS consists of a set of altered bowel habits over a period of time and includes abdominal pain and discomfort. The pathogenesis of IBS is not completely understood, although it has been noted that various mechanisms are involved determining the onset of symptoms. The risk factors include antibiotics, enteric infection, food intolerance, altered pain perception, altered brain-gut interaction, dysbiosis, increased intestinal permeability, visceral hypersensitivity, and increased activation of the gut mucosal immune system. There has been interest regarding the possible role of food in IBS. Diet is crucial for managing IBS; it plays an important role both in the genesis and in the improvement of symptoms. The aim of the study was to summarize the evidence from the literature, which explains those causes tending to promoting IBS symptoms, such as food content short-chain carbohydrates and the presence of food allergy or food intolerance

Optimal sizing of energy communities with fair revenue sharing and exit clauses: value, role and business model of aggregators and users

Energy communities (ECs) are essential policy tools to meet the Energy Transition goals, as they can promote renewable energy sources, demand side management, demand response and citizen participation in energy matters. However, to fully unleash their potential, their design and scheduling requires a coordinated technical operation that the community itself may be ill-equipped to manage, in particular in view of the mutual technical and legal constraints ensuing from a coordinated design. Aggregators and Energy Service COmpanies (ESCOs) can perform this support role, but only provided that their goals are aligned to those of the community, not to incur in the agency problem. In this study, we propose a business model for aggregators of ECs, and its corresponding technical optimization problem, taking into account all crucial aspects: i) alleviating the risk of the agency problem, ii) fairly distributing the reward awarded to the EC, iii) estimating the fair payment for the aggregator services, and iv) defining appropriate exit clauses that rule what happens when a user leaves the EC. A detailed mathematical model is derived and discussed, employing several fair and theoretically-consistent reward distribution schemes, some of which are, to the best of our knowledge, proposed here for the first time. A case study is developed to quantify the value of the aggregator and compare the coordinated solution provided by the aggregator with non-coordinated configurations, numerically illustrating the impact of the reward distribution schemes. The results show that, in the case study, the aggregator enables reducing costs by 16% with respect to a baseline solution, and enables reaching 52.5% renewable share and about 46% self/shared consumption, whereas these same numbers are only 28-35% for the non-coordinated case. Our results suggest that the aggregator fair retribution is around 16-24% the added benefit produced with respect to the non-coordinated solution, and that stable reward distribution schemes such as Shapley/Core or Nucleolus are recommended. Moreover, the results highlight the unwanted effect that some non-cooperative ECs may have an added benefit without providing any positive effect to the power system. Our work lays the foundations for future studies on business models of aggregators for ECs and provides a methodology and preliminary results that can help policy makers and developers in tailoring national-level policies and market-offerings