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The distortion of homogeneous isotropic turbulence interacting with a porous cylinder is calculated by means of the rapid distortion theory (RDT). The porous treatment, characterised by a constant static permeability, is modelled as an impedance boundary condition accounting for the Darcy's flow within the body. The RDT algorithm is first validated through comparisons with published velocity measurements in the stagnation region of an impermeable cylinder placed downstream of a turbulence grid. Subsequently, the impact of porosity on the velocity field is investigated through the analysis of the one-dimensional spectra at different locations near the body and the velocity variance along the stagnation streamline. The porous surface affects the incoming turbulence distortion near the cylinder by reducing the blocking effect of the body and by altering the vorticity deformation caused by the mean flow. The former leads to an attenuation of the one-dimensional velocity spectrum in the low-frequency range, whereas the latter results in an amplification of the high-frequency components. This trend is found to be strongly dependent on the turbulence scale and influences the evolution of the velocity fluctuations in the stagnation region. The porous RDT is finally adapted to model the turbulence distortion in the vicinity of the leading edge of a NACA-0024 profile fitted with melamine foam. The good agreement between the calculations and the experimental results demonstrates that the present methodology can improve the understanding of the physical mechanisms involved in the aerofoil-turbulence interaction noise reduction through porosity and be instrumental in designing such passive noise-mitigation treatments.
Borderline personality disorder (BPD) is characterized by pervasive instability in moods, interpersonal relationships, self-image, and behavior. This disorder is associated with a significant rate of suicide attempts and completed suicides (4 to 10%), a major impairment in social functioning and an increased healthcare utilization cost. Treatments available include psychotherapy and pharmacotherapy. Research has shown some efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) on post-traumatic stress disorder and mood disorder which both share common biological or clinical features with BPD. It is then likely that rTMS might prove efficient on BPD symptoms.
A review of the literature on neuroimaging and neuropsychology of BPD shows a hypoactivity of the dorsolateral prefrontal cortex which may be a potential target site for rTMS.
We will conduct a pilot randomized sham-controlled trial on 30 BPD patients assessing the efficacy of a 10-day course of daily rTMS on neuropsychological tasks, BPD symptoms severity, risk taking behaviour, depression and general psychopathology.
The VAMDC Consortium intended to find a way for users to cite the datasets accessed through the infrastructure. The Research Data Alliance Data citation working group provided the researchers and data centres communities with a recommendation to identify and cite dynamic data. This recommendation perfectly matched the VAMDC needs: the proposed solution relies on a query centric view and the set-up of a Query Store. Data should be stored in a versioned time-stamped manner and accessed through queries. The Query Store we implemented for VAMDC is interlinked with Zenodo. Since Zenodo is indexed in OpenAIRE and since the latter implements Scholix, VAMDC indirectly implements Scholix via its Query Store. The paper outlines the successes and limitations of the above approach.
A better understanding of the dynamics of different particulate organic matter (OM) pools in the coastal carbon budget is a key issue for quantifying the role of the coastal ocean in the global carbon cycle. To elucidate the benthic component of this carbon cycle at the land-sea interface, we investigated the carbon isotope signatures (δ13C and ∆14C) in the sediment pore waters dissolved inorganic carbon (DIC) in addition to the sediment OM to constrain the origin of the OM mineralized in sediments. The study site is located at the outlet of the Rhône River (Mediterranean Sea), which was chosen because this river is one of the most nuclearized rivers in Europe and nuclear 14C can serve as a tracer to follow the fate of the OM discharged by the river to the coastal sea. The ∆14C results found in the pore waters DIC show a general offset between buried and mineralized OM following a preferential mineralization model of young and fresh particles. For example, we found that the sediment OM has values with a mean ∆14C=–33‰ at sampling stations near the river mouth whereas enriched ∆14C values around +523‰ and +667‰ respectively were found for the pore waters DIC. This indicates complete mineralization of a riverine fraction of OM enriched in 14C in the river conduit during in-stream photosynthesis. In shelf sediments, the ∆14C of pore waters DIC is slightly enriched (+57‰) with sediment OM reaching –570‰. A mixing model shows that particles mineralized near the river mouth are certainly of riverine phytoplanktonic origin whereas OM mineralized on the shelf is of marine origin. This work highlights the fact that pore waters provide additional information compared to sediments alone and it seems essential to work on both pools to study the carbon budget in river prodelta.
Background: Transient neurological symptoms in patients with subdural hematoma (SDH) are often attributed to secondary epilepsy despite a negative workup. We believe a significant proportion of these patients could rather suffer from cortical spreading depolarization (CSD). Methods: We performed a retrospective case-control study of patients with transient neurological symptoms post-SDH evacuation between 1996 and 2017. The clinical features of patients with negative EEG were compared to those with positive EEG (ictal or interictal abnormalities) and a clinical scoring system was created. Results: 59 patients were included, 20 (34%) with a positive EEG. Speech-related symptoms (OR 4.8, p=0.018) and prolonged episodes (OR 23.1, p=0.001) were associated with a negative EEG. Clonic movements (OR 0.014, p<0.0005), impaired awareness (OR 0.013, p<0.0005), positive symptoms (OR 0.05, p<0.0001), complete response to standard antiepileptic drugs (OR 0.06, p=0.007) and mortality (OR 0.021, p=0.003) were associated with a positive EEG. We built a clinical score based on these features, which showed a 90% sensitivity and 100% specificity. Conclusions: We believe that the differences observed between both groups were driven by the presence of CSD rather than seizure in the case group. Our proposed scoring system can help predict EEG results and may be useful to identify CSD in future trials.
In this paper, first results comparing modified Longin and ninhydrin collagen extraction methodologies are presented. The goal of this study is to investigate the bones of several species with different ages, preservation conditions, and collagen contents to determine the most suitable preparation method. Different types of samples are used such as VIRI samples, previously dated bones, and background samples. Each bone has undergone elemental analysis, infrared analysis, and 14C measurement. The results are presented and the advantages and disadvantages of each preparation method are discussed. In general, results obtained by the two methods are in accordance with the consensus value for 2σ uncertainty. For VIRI I and a mammoth bone, the ninhydrin preparation gives, respectively, 8450±70 BP and 14,870±60 BP whereas the modified Longin process gives 8365±45 BP and 14,750±100 BP in agreement with the expected values. From the experimental point of view, the modified Longin process is easier to implement than the ninhydrin protocol. From this approach, we can conclude that the modified Longin process could be preferred in most cases and particularly when the amount of bone is small and the sample is not too contaminated.
The main objective of this report is to present the dating process routinely applied to different types of samples at the Laboratoire de Mesure du Carbone 14 (LMC14). All the results and protocols refer to our procedures over the last 5 years. A description of the sorting and chemical pretreatments of the samples as well as the extraction and graphitization of CO2 are reported. Our last study concerning the degradation of the blank level according to the storage time of the targets between graphitization and accelerator mass spectrometry (AMS) measurement is also presented. This article also provides information on how to submit a valid laboratory sample. We give details relating to sampling procedures on site as well as contamination issues relative to the 14C dating methodology.
The Grotte Cosquer (southeastern France) is a Paleolithic painted cave only accessible by a deep-water dive. The cave has yielded numerous Paleolithic engravings and drawings, which were produced from wood charcoal. This article presents new radiocarbon dates obtained on samples collected in 2012 directly on 17 parietal representations and at the soil surface, and discusses the 14C results obtained since the discovery of the cave in 1992. A total of 41 samples were dated with ages ranging from 33,000 to 20,000 cal BP. They show that the cave was intermittently decorated over about 10,000 yr.
Due to the diversity of antibody (Ab)-based biochips chemistries available and the little knowledge about biochips resistance to space constraints, immobilization of Abs on the surface of the biochips dedicated to Solar System exploration is challenging. In the present paper, we have developed ten different biochip models including covalent or affinity immobilization with full-length Abs or Ab fragments. Ab immobilizations were carried out in oriented/non-oriented manner using commercial activated surfaces with N-hydroxysuccinic ester (NHS-surfaces) or homemade surfaces using three generations of dendrimers (dendrigraft of poly L-lysine (DGL) surfaces). The performances of the Ab -based surfaces were cross-compared on the following criteria: (i) analytical performances (expressed by both the surface density of immobilized Abs and the amount of antigens initially captured by the surface) and (ii) resistance of surfaces to preparation procedure (freeze-drying, storage) or spatial constraints (irradiation and temperature shifts) encountered during a space mission. The latter results have been expressed as percentage of surface binding capacity losses (or percentage of remaining active Abs). The highest amount of captured antigen was achieved with Ab surfaces having full-length Abs and DGL-surfaces that have much higher surface densities than commercial NHS-surface. After freeze-drying process, thermal shift and storage sample exposition, we found that more than 80% of surface binding sites remained active in this case. In addition, the resistance of Ab surfaces to irradiation with particles such as electron, carbon ions or protons depends not only on the chemistries (covalent/affinity linkages) and strategies (oriented/non-oriented) used to construct the biochip, but also on the type, energy and fluence of incident particles. Our results clearly indicate that full-length Ab immobilization on NHS-surfaces and DGL-surfaces should be preferred for potential use in instruments for planetary exploration.
The flow and noise created by sawtooth trailing-edge serrations has been studied experimentally at a low Reynolds number. Experiments have been performed on a flat-plate model with an elliptical leading edge and an asymmetrically bevelled trailing edge at Reynolds numbers of Rec = 1 × 105–1.3 × 105, based on chord. Wide serrations with a wavelength (λs) to amplitude (2h) ratio of λs/h = 0.6 were found to reduce the overall sound pressure level by up to 11dB. In contrast, narrower serrations with λs/h = 0.2 produce tonal noise and increase the overall noise level by up to 4dB. Intense vortices across the span of the trailing edge with narrow serrations are shown to be the source of tonal noise. Wide serrations reduce turbulent velocity fluctuations at low frequencies which explains the lower radiated noise. The narrow serrations that produce low Reynolds number tonal noise were shown previously to be effective at higher Reynolds numbers (Rec > 2 × 105), demonstrating that care is needed to fully understand the flow field over serrations for all intended operating conditions.
Several instruments based on immunoassay techniques have been proposed for life-detection experiments in the framework of planetary exploration but few experiments have been conducted so far to test the resistance of antibodies against cosmic ray particles. We present several irradiation experiments carried out on both grafted and free antibodies for different types of incident particles (protons, neutrons, electrons and 12C) at different energies (between 9 MeV and 50 MeV) and different fluences. No loss of antibodies activity was detected for the whole set of experiments except when considering protons with energy between 20 and 30 MeV (on free and grafted antibodies) and fluences much greater than expected for a typical planetary mission to Mars for instance. Our results on grafted antibodies suggest that biochip-based instruments must be carefully designed according to the expected radiation environment for a given mission. In particular, a surface density of antibodies much larger than the expected proton fluence would prevent significant loss of antibodies activity and thus assuring a successful detection.
A growing body of literature has explored the influence of physical activity on brain structure and function. While the mechanisms of this relationship remain largely speculative, recent research suggests that one of the effects of physical exercise is an increase in synaptic long-term potentiation (LTP). This has not yet been explored directly in humans due to the difficulty of measuring LTP non-invasively. However, we have previously established that LTP-like changes in visual-evoked potentials (VEPs) can be measured in humans. Here, we investigated whether physical fitness status affects the degree of visual sensory LTP. Using a self-report measure of physical activity, participants were split into two groups: a high-activity group, and a low-activity group. LTP was measured and compared between the two groups using the previously established electroencephalography-LTP paradigm, which assesses the degree to which the N1b component of the VEP elicited by a sine grating is potentiated (enhanced) following a rapid “tetanic” presentation of that grating. Both groups demonstrated increased negativity in the amplitude of the N1b component of the VEP immediately after presentation of the visual “tetanus,” indicating potentiation. However, after a 30-min rest period, the N1b for the high-activity group remained potentiated while the N1b for the low-activity group returned to baseline. This study presents the first evidence for the impact of self-reported levels of physical activity on LTP in humans, and sheds light on potential neurological mechanisms underlying the relationship between physical fitness and cognition. (JINS, 2015, 21, 831–840)
The VAMDC Consortium is a worldwide consortium which federates Atomic and Molecular databases through an e-science infrastructure and a political organisation. About 90% of the inter-connected databases handle data that are used for the interpretation of spectra and for the modeling of media of many fields of astrophysics. This paper presents how the VAMDC Consortium is organised in order to publish atomic and molecular data for astrophysics.
Quantitative assessment of mitigation measures for nitrogen (N) pollution requires adequate models, good knowledge of catchment functioning and a thorough understanding of agricultural systems and stakeholder constraints. The current paper analyses a set of results from simulations, with two models, of agricultural changes in two catchments in different contexts with different constraints. The results show that reducing N inputs and increasing grassland areas are the most efficient measures, not only because they reduce N fluxes in streams but also because they enhance N use by agriculture and the whole catchment system. Introducing catch crops, hedgerows and riparian buffers are interesting complementary measures but of limited impact when implemented alone. These results are sensitive to the way mitigation measures are translated into model inputs, and their operational implications are discussed.
According to the World Health Organization guidelines, field tests, in the context of a bid for the supply of alcohol-based hand rubs, should take into account climatic region, test period, products already in use, and type of use (hygienic or surgical) when assessing tolerance. This laborious method is often contested.
To conduct a post hoc analysis of the data of a large bid, including 5 factors, to validate the relevance of their inclusion.
For the purposes of the bid, products were compared in terms of the 4 World Health Organization tolerance criteria (appearance, intactness, moisture content, sensation) during product testing and were separated into groups on the basis of the studied factors. The post hoc analysis method included (1) comparison of the mean before-and-after difference based on the self-evaluation of the skin with the 4 World Health Organization tolerance criteria, between climatic regions, periods, products in use, test product, and the type of use; (2) generalized linear models, taking into account all studied factors.
The analysis included data for 1,925 pairs of professionals. The means of the differences observed were independently and significantly associated with the test period (P<.001), the hygienic or surgical use (P=.010 to .041, not significant for appearance), the product already in use (significant for appearance P=.021), and the test product (P<.001). The association with climatic region was found to be significant only in the nonadjusted analysis.
The type of use, the test period, and the product in use should be taken into account when designing field tests of alcohol-based hand rubs.
We present here the new line installed at the LMC14 laboratory (Saclay, France) for dissolved inorganic carbon (DIC) extraction from marine and freshwater samples. The operating system and extraction process are described. The efficiency of the line design was checked, and the background (0.42 ± 0.11 pMC) and the reproducibility on artificial samples obtained by dissolution of IAEA-C1, IAEA-C2, and commercial bicarbonate in water were evaluated. An intercomparison with an independent lab (IDES) was also carried out on a natural sample. The line processes 3 samples a day under a helium flow and is able to run samples up to 40,000 ka.
The Laboratoire des Sciences du Climat et de l'Environnement (LSCE) research program on prehistoric art conducts chronological studies of parietal representations with their associated archaeological context. This multidisciplinary approach provides chronological arguments about the creation period of parietal representations. This article presents chronological investigations carried out in several decorated caves in France (La Grande Grotte, Labastide, Lascaux, La Tête-du-Lion, Villars) and Spain (La Garma, Nerja, La Pileta, Urdiales). Several types of organic materials, collected from different areas of the caves close to the walls and in connection with parietal art, were dated to determine the periods of human presence in the cave, a presence that may have been related to artistic activities. These new radiocarbon results range from 33,000–29,000 (La Grande Grotte) to 16,000–14,000 cal BP (Urdiales).
The Artemis accelerator mass spectrometry (AMS) facility, installed in 2003 in Saclay, France, is devoted to radiocarbon measurements. Samples are submitted by scientists in the fields of Quaternary geology, environmental sciences, and archaeology. The entire preparation process, originally optimized for samples with about 1 mg of carbon, has been tested in recent years for samples with a lower carbon content. In particular, we prepared and measured carbonate and organic background and reference samples ranging in mass from 0.01 to 1 mg C. These tests helped define our protocol's practical limits and determine necessary improvements. Furthermore, our experiments demonstrated that satisfactory graphitization yields (80% and higher) and low background values can be obtained with samples down to 0.2 mg of carbon. For handling smaller samples, we developed a specific process. We tested smaller reactors (5 mL in volume) and adapted the reduction parameters (H2 pressure and temperature) accordingly. We also tested the effect of a chemical water trap on graphitization yields and 14C results. This paper presents in detail the aforementioned developments and reports the 14C results obtained for background and standard small samples prepared with the modified reactors.
The Artemis accelerator mass spectrometry (AMS) facility is dedicated to high-precision radiocarbon measurements. It routinely measures over 4500 samples a year for French laboratories. This paper is a status report, showing the measurements of standard, blank, and FIRI intercomparison samples. Since 2008, research and development programs have been established by the Artemis team. During the collaborations with other research laboratories, intercomparisons on archaeological samples were performed and are listed here to show the quality of the Artemis measurements. Three areas of specific research and development are investigated: technical development, beam optic simulations, and specific archaeological studies. The technical developments of the facility are based on the setup of a new bench for water sample preparation and routine microsample preparation and measurement. Beam optic simulations are carried out to control the quality of the measurement related to the tuning of the facility. International collaborations are always in progress. In 2012, the programs include improving the accuracy of reigns for the dynastic Egypt period and the 14C dating of ancient iron.
Legumes are crops that develop in cropping systems with relatively low inputs and are suitable to a more sustainable agriculture. Successful crop establishment, which is crucial for reliable plant production, depends on seed quality, environmental factors and genotypes. We studied pea and bean germination and seedling growth at various temperatures (5–40°C) and water potentials ( − 0.2 to − 1.5 MPa) using winter and spring pea and two common bean seeds produced in different conditions. The germination base temperature was − 1.1°C for pea seeds, and seeds of the winter genotype germinated more rapidly than those of the spring genotype. The base temperature for bean seed germination was 5.1–9.6°C, depending on the seed lot. The germination base water potential was about − 2 MPa for both species. The base temperatures for shoot elongation were higher (3–6°C) than those for germination. A review of the literature on other legumes confirmed that the differences in the responses of the legume seeds and seedlings to different temperatures were associated with their geographic origin. These results help understanding of pea and bean crop establishment, provide crop model parameter values and contribute to the search for genetic variability.