231 research outputs found
Ethics assessment in research proposals adopting CRISPR technology
The rapid and exponential growth of genome editing has posed many challenges for bioethics. This article briefly explains the nature of the technique and the particularly rapid development of Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) technology. The international and, specifically, European-level systems for assessing the ethical issues consequent on these developments are outlined and discussed. The challenges posed by cases in China are summarized to raise concerns about how a more shared, universally consistent appraisal of bioethical issues can be promoted
Towards the Validation of a Driving Simulator-Based Hazard Response Test for Novice Drivers
Underdeveloped hazard perception skills are associated with the higher crash risk of young novice drivers. Some driver licensing authorities use hazard perception tests (HPTs) that measure reaction times or multiple-choice responses to brief driving scenes videotaped from a vehicle traveling at legal speeds. To date, evaluations of the association between HPT scores and novice driver crash rates have been mixed. Several possible explanations for this are: high-risk novice drivers may offset good HP skills by exceeding the speed limit; current HPTs do not capture behavioral responses to hazards from candidates whose attention is engaged in the driving task; there is no established typology of driving hazards that might produce a finer-grained analysis of test results, and; current measures of HP ability may lack sensitivity. To address these potential flaws, we developed a driving simulatorbased Hazard Response Test (HRT) in which drivers respond to sixteen programmed hazard events derived from a proposed typology that combines visible or hidden, real or potential conflicts, while driving over three continuous routes. The study results indicate no statistically significant difference in crash rates between young novice and experienced drivers. However, a novel, composite measure called the Continuous Time to Collision (C-TTC) did discriminate between young novice and older experienced drivers. Additional research on the validation of this measure and further refinement of the hazard typology could contribute to the creation of a standardized, driving simulator-based HRT for use in the evaluation of novice, professional and aging drivers
Ethics Dumping Case Studies from North-South Research Collaborations
This book provides original, up-to-date case studies of âethics dumpingâ that were largely facilitated by loopholes in the ethics governance of low and middle-income countries. It is instructive even to experienced researchers since it provides a voice to vulnerable populations from the fore mentioned countries. Ensuring the ethical conduct of North-South collaborations in research is a process fraught with difficulties. The background conditions under which such collaborations take place include extreme differentials in available income and power, as well as a past history of colonialism, while differences in culture can add a new layer of complications. In this context, up-to-date case studies of unethical conduct are essential for research ethics training
Probabilistic functional tractography of the human cortex revisited
In patients with pharmaco-resistant focal epilepsies investigated with intracranial electroencephalography (iEEG), direct electrical stimulations of a cortical region induce cortico-cortical evoked potentials (CCEP) in distant cerebral cortex, which properties can be used to infer large scale brain connectivity. In 2013, we proposed a new probabilistic functional tractography methodology to study human brain connectivity. We have now been revisiting this method in the F-TRACT project (f-tract.eu) by developing a large multicenter CCEP database of several thousand stimulation runs performed in several hundred patients, and associated processing tools to create a probabilistic atlas of human cortico-cortical connections. Here, we wish to present a snapshot of the methods and data of F-TRACT using a pool of 213 epilepsy patients, all studied by stereo-encephalography with intracerebral depth electrodes. The CCEPs were processed using an automated pipeline with the following consecutive steps: detection of each stimulation run from stimulation artifacts in raw intracranial EEG (iEEG) files, bad channels detection with a machine learning approach, model-based stimulation artifact correction, robust averaging over stimulation pulses. Effective connectivity between the stimulated and recording areas is then inferred from the properties of the first CCEP component, i.e. onset and peak latency, amplitude, duration and integral of the significant part. Finally, group statistics of CCEP features are implemented for each brain parcel explored by iEEG electrodes. The localization (coordinates, white/gray matter relative positioning) of electrode contacts were obtained from imaging data (anatomical MRI or CT scans before and after electrodes implantation). The iEEG contacts were repositioned in different brain parcellations from the segmentation of patients' anatomical MRI or from templates in the MNI coordinate system. The F-TRACT database using the first pool of 213 patients provided connectivity probability values for 95% of possible intrahemispheric and 56% of interhemispheric connections and CCEP features for 78% of intrahemisheric and 14% of interhemispheric connections. In this report, we show some examples of anatomo-functional connectivity matrices, and associated directional maps. We also indicate how CCEP features, especially latencies, are related to spatial distances, and allow estimating the velocity distribution of neuronal signals at a large scale. Finally, we describe the impact on the estimated connectivity of the stimulation charge and of the contact localization according to the white or gray matter. The most relevant maps for the scientific community are available for download on f-tract. eu (David et al., 2017) and will be regularly updated during the following months with the addition of more data in the F-TRACT database. This will provide an unprecedented knowledge on the dynamical properties of large fiber tracts in human.Peer reviewe
Protection of Macaques with Diverse MHC Genotypes against a Heterologous SIV by Vaccination with a Deglycosylated Live-Attenuated SIV
HIV vaccine development has been hampered by issues such as undefined correlates of protection and extensive diversity of HIV. We addressed these issues using a previously established SIV-macaque model in which SIV mutants with deletions of multiple gp120 N-glycans function as potent live attenuated vaccines to induce near-sterile immunity against the parental pathogenic SIVmac239. In this study, we investigated the protective efficacy of these mutants against a highly pathogenic heterologous SIVsmE543-3 delivered intravenously to rhesus macaques with diverse MHC genotypes. All 11 vaccinated macaques contained the acute-phase infection with blood viral loads below the level of detection between 4 and 10 weeks postchallenge (pc), following a transient but marginal peak of viral replication at 2 weeks in only half of the challenged animals. In the chronic phase, seven vaccinees contained viral replication for over 80 weeks pc, while four did not. Neutralizing antibodies against challenge virus were not detected. Although overall levels of SIV specific T cell responses did not correlate with containment of acute and chronic viral replication, a critical role of cellular responses in the containment of viral replication was suggested. Emergence of viruses with altered fitness due to recombination between the vaccine and challenge viruses and increased gp120 glycosylation was linked to the failure to control SIV. These results demonstrate the induction of effective protective immune responses in a significant number of animals against heterologous virus by infection with deglycosylated attenuated SIV mutants in macaques with highly diverse MHC background. These findings suggest that broad HIV cross clade protection is possible, even in hosts with diverse genetic backgrounds. In summary, results of this study indicate that deglycosylated live-attenuated vaccines may provide a platform for the elucidation of correlates of protection needed for a successful HIV vaccine against diverse isolates
Interlaboratory comparison study of the Colony Forming Efficiency assay for assessing cytotoxicity of nanomaterials
Nanotechnology has gained importance in the past years as it provides opportunities for industrial growth and innovation. However, the increasing use of manufactured nanomaterials (NMs) in a number of commercial applications and consumer products raises also safety concerns and questions regarding potential unintended risks to humans and the environment. Since several years the European Commissionâs Joint Research Centre (JRC) is putting effort in the development, optimisation and harmonisation of in vitro test methods suitable for screening and hazard assessment of NMs. Work is done in collaboration with international partners, in particular the Organisation for Economic Co-operation and Development (OECD). This report presents the results from an interlaboratory comparison study of the in vitro Colony Forming Efficiency (CFE) cytotoxicity assay performed in the frame of OECD's Working Party of Manufactured Nanomaterials (WPMN). Twelve laboratories from European Commission, France, Italy, Japan, Poland, Republic of Korea, South Africa and Switzerland participated in the study coordinated by JRC. The results show that the CFE assay is a suitable and robust in vitro method to assess cytotoxicity of NMs. The assay protocol is well defined and is easily and reliably transferable to other laboratories. The results obtained show good intra and interlaboratory reproducibility of the assay for both the positive control and the tested nanomaterials.
In conclusion the CFE assay can be recommended as a building block of an in vitro testing battery for NMs toxicity assessment. It could be used as a first choice method to define dose-effect relationships for other in vitro assays.JRC.I.4-Nanobioscience
ESC Joint Working Groups on Cardiovascular Surgery and the Cellular Biology of the Heart Position Paper: Perioperative myocardial injury and infarction in patients undergoing coronary artery bypass graft surgery
International audienc
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