There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be alt...There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index (BMI). A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling (TUNEL) assay, we observed an increased rate of sDerm DNA damage in obese men (odds ratio (95% confidence interval): 2.5 (1.2-5.1)).展开更多
As a proposed detector,the giant radio array for neutrino detection(GRAND)is primarily designed to discover and study the origin of ultra-high-energy cosmic rays,with ultra-high-energy neutrinos presenting the main me...As a proposed detector,the giant radio array for neutrino detection(GRAND)is primarily designed to discover and study the origin of ultra-high-energy cosmic rays,with ultra-high-energy neutrinos presenting the main method for detecting ultra-high-energy cosmic rays and their sources.The main principle is to detect radio emissions generated by ultra-high-energy neutrinos interacting with the atmosphere as they travel.GRAND is the largest neutrino detection array to be built in China.GRANDProto35,as the first stage of the GRAND experiment,is a coincidence array composed of radio antennas and a scintillation detector,the latter of which,as a traditional detector,is used to perform cross-validation with radio detection,thus verifying the radio detection efficiency and enabling study of the background exclusion method.This study focused on the implementation of the optimization simulation and experimental testing of the performance of the prototype scintillation detector used in GRANDProto35.A package based on GEANT4 was used to simulate the details of the scintillation detector,including the optical properties of its materials,the height of the light guide box,and position inhomogeneity.The surface of the scintillator and the reflective materials used in the detector was optimized,and the influence of light guide heights and position inhomogeneity on the energy and time resolutions of the detector was studied.According to the simulation study,the number of scintillator photoelectrons increased when changing from the polished surface to the ground surface,with the appropriate design height for the light guide box being 50 cm and the appropriate design area for the scintillator being 0.5 m^(2).The performance of the detector was tested in detail through a coincidence experiment,and the test results showed that the number of photoelectrons collected in the detector was$84 with a time resolution of~1 ns,indicating good performance.The simulation results were consistent with those obtained from the tests,which also verified the reliability of the simulation software.These studies provided a full understanding of the performance of the scintillation detector and guidance for the subsequent operation and analysis of the GRANDProto35 experimental array.展开更多
Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been ...Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been chosen as one of unbumed hydrocarbon present in exhaust gas engine during the cold start of vehicles.The comparison between the different discharge geometries has been possible using the specific input energy(SIE)as relevant parameter for pollutant removal process control considering the differences in the electrical characteristics and the differences of gas flow.The best naphthalene degradation is obtained in the wire-to cylinder(WTC)corona discharge and the stem-to-cylinder DBD with an energy costβrespectively of 10 and 20 J L^-1.The main by-products issues of the naphthalene oxidation are CO2 and CO reaching 45%in Multi-Pin-to-Plan corona discharge.We detected polyaromatic hydrocarbons in the gas phase(few ppm)and in the solid phase deposited in the reactors.The introduction of water in the discharges promotes the naphthalene degradation by OH-atom,which has better oxidising power than O-atom in dry air.展开更多
Neutrino detection in the 100 PeV energy region is the ultimate means of studying the origin of ultra-highenergy cosmic rays,in which the large radio detection array giant radio array for neutrino detection(GRAND)proj...Neutrino detection in the 100 PeV energy region is the ultimate means of studying the origin of ultra-highenergy cosmic rays,in which the large radio detection array giant radio array for neutrino detection(GRAND)project aims to use to decipher this century-old problem.The GRANDProto35 compact array is a microform of 35 radio prototype detectors for the GRAND experiment,which verifies the reliability of GRAND performance through operation,and data analysis of the prototype detectors.As radio detectors are a novel development in recent years,and their indexes need to be verified by traditional detectors,the GRAND Cooperation Group designed and constructed the GRANDProto35 coincidence array composed of radio detectors and scintillation detectors.This study simulated the changes in detection efficiency,effective area,and event rate of cosmic rays with zenith angle based on this coincidence array.The study found that the 1017 eV energy region is sensitive to GRANDProto35 detection.When the energy exceeded 1017 eV,the array detection efficiency could reach more than 95%and the effective area was up to*29106 m2.A simulation study on cosmic ray events with large zenith angles showed that the event rate detected by the array decreased significantly with increasing zenith angle,and the event rate of cosmic rays was approximately 0.1 per day for a zenith angle of 75.This serves as the background pollution rate for neutrino observation caused by largeangle cosmic-ray events,providing an important reference for further experiments.The study results will be verified after the joint operation of the coincidence array.展开更多
We elaborate an error budget for the long-term accuracy of IGS(International Global Navigation Satellite System Service) polar motion estimates, concluding that it is probably about 25-30 μas(1-sigma)overall, alt...We elaborate an error budget for the long-term accuracy of IGS(International Global Navigation Satellite System Service) polar motion estimates, concluding that it is probably about 25-30 μas(1-sigma)overall, although it is not possible to quantify possible contributions(mainly annual) that might transfer directly from aliases of subdaily rotational tide errors. The leading sources are biases arising from the need to align daily, observed terrestrial frames, within which the pole coordinates are expressed and which are continuously deforming, to the secular, linear international reference frame. Such biases are largest over spans longer than about a year. Thanks to the very large number of IGS tracking stations, the formal covariance errors are much smaller,around 5 to 10 μas. Large networks also permit the systematic frame-related errors to be more effectively minimized but not eliminated. A number of periodic errors probably also influence polar motion results, mainly at annual, GPS(Global Positioning System) draconitic, and fortnightly periods, but their impact on the overall error budget is unlikely to be significant except possibly for annual tidal aliases. Nevertheless, caution should be exercised in interpreting geophysical excitations near any of the suspect periods.展开更多
The second(O2)observational campaign of gravitational waves(GWs)organized by the LIGO/Virgo Collaborations has led to several breakthroughs such as the detection of GW signals from merger systems involving black holes...The second(O2)observational campaign of gravitational waves(GWs)organized by the LIGO/Virgo Collaborations has led to several breakthroughs such as the detection of GW signals from merger systems involving black holes or neutrons stars.During O2,14 GW alerts were sent to the astronomical community with sky regions mostly covering over hundreds of square degrees.Among them,six were finally confirmed as real astrophysical events.Since 2013,a new set of ground-based robotic telescopes called Ground-based Wide Angle Camera system(GWAC)project and its pathfinder mini-GWAC has been developed to contribute to the various challenges of multi-messenger and time domain astronomy.The GWAC system is built up in the framework of the ground-segment system of the SVOM mission that will be devoted to the study of the multi-wavelength transient sky in the next decade.During O2,only the mini-GWAC telescope network was fully operational.Due to the wide field of view and fast automatic follow-up capabilities of the mini-GWAC telescopes,they were adept to efficiently cover the sky localization areas of GW event candidates.In this paper,we present the mini-GWAC pipeline we have set up to respond to GW alerts and we report our optical follow-up observations of eight GW alerts detected during the O2 run.Our observations provided the largest coverage of the GW localization areas with a short latency made by any optical facility.We found tens of optical transient candidates in our images,but none of those could be securely associated with any confirmed black hole-black hole merger event.Based on this first experience and the near future technical improvements of our network system,we will be more competitive in detecting the optical counterparts from some GW events that will be identified during the upcoming O3 run,especially those emerging from binary neutron star mergers.展开更多
We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with po...We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with polynomials of degrees 1 to 9. A significant ~60-yr oscillation is accounted for as soon as degree 4 is reached. This oscillation is even better modeled as a broken line, more precisely a series of ~30-yr long linear segments, with slope breaks (singularities) in ~1904, ~1940, and ~1974 (±3 yr), and a possible recent occurrence at the turn of the 20th century. Oceanic indices PDO (Pacific Decadal Oscillation) and AMO (Atlantic Multidecadal Oscillation) have undergone major changes (respectively of sign and slope) roughly at the same times as the temperature slope breaks. This can be interpreted with a system of oceanic non-linear coupled oscillators with abrupt mode shifts. Thus, the Earth’s climate may have entered a new mode (a new ~30-yr episode) near the turn of the 20th century: no further temperature increase, a dominantly negative PDO index and a decreasing AMO index might be expected for the next decade or two.展开更多
In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active ...In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance (EAS) exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action (MOA) of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool (together with the epidemiological approach) for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.展开更多
Family-based tests of association between a genetic marker and a disease constitute a common design to dissect the genetic architecture of complex traits. The FBAT software is one of the most popular tools to perform ...Family-based tests of association between a genetic marker and a disease constitute a common design to dissect the genetic architecture of complex traits. The FBAT software is one of the most popular tools to perform such studies. However, researchers are also often interested in the genetic contribution to a more specific manifestation of the phenotype (e.g. severe vs. non-severe form) known as a secondary outcome. Here, what we demonstrate is the limited power of the classical formulation of the FBAT statistic to detect the effect of genetic variants that influence a secondary outcome, in particular when these variants also impact on the onset of the disease, the primary outcome. We prove that this loss of power is driven by an implicit hypothesis, and we propose a derivation of the original FBAT statistic, free from this implicit hypothesis. Finally, we demonstrate analytically that our new statistic is robust and more powerful than FBAT for the detection of association between a genetic variant and a secondary outcome.展开更多
A patient treated with a vitamin K antagonist (VKA) since the implantation of two mechanical heart valves developed acute anemia after the extraction of a tooth. This case report and data in the literature indicate a ...A patient treated with a vitamin K antagonist (VKA) since the implantation of two mechanical heart valves developed acute anemia after the extraction of a tooth. This case report and data in the literature indicate a need for specific measures before, during, and after oral surgery in patients taking anticoagulant therapy: 1) the bleeding risk should be evaluated before the procedure. The INR should be measured routinely, 2) the procedure should be scheduled early in the week to allow an evaluation at the fibrinolysis peak, i.e., 48 to 72 hours after surgery, which is the time of greatest risk of delayed bleeding, 3) the surgical procedure should be appropriate for the elevated bleeding risk, 4) postoperative monitoring is of the most importance, as bleeding is usually delayed in patients on VKA therapy, 5) when poor treatment adherence is expected, day-hospital admission is useful to ensure that the postoperative protocol is implemented properly and to detect early bleeding. The treatment of post-extraction acute anemia includes local hemostasis protocol with the revision of the socket followed by red-blood-cell pack transfusion. A daily fluindione dosage control, and a normal hemoglobin level will allow the patient to leave the hospital.展开更多
In order to study social inequalities, indices can be used to summarize the multiple dimensions of the socioeconomic status. As a part of the Equit’Area Project, a public health program focused on social and environm...In order to study social inequalities, indices can be used to summarize the multiple dimensions of the socioeconomic status. As a part of the Equit’Area Project, a public health program focused on social and environmental health inequalities;a statistical procedure to create (neighborhood) socioeconomic indices was developed. This procedure uses successive principal components analyses to select variables and create the index. In order to simplify the application of the procedure for non-specialists, the R package SesIndexCreatoR was created. It allows the creation of the index with all the possible options of the procedure, the classification of the resulting index in categories using several classical methods, the visualization of the results, and the generation of automatic reports.展开更多
Background and objective: Generating and characterizing primate models of epileptic seizures are important for understanding pathophysiology of diseases and establishing preclinical efficacy of novel therapies like De...Background and objective: Generating and characterizing primate models of epileptic seizures are important for understanding pathophysiology of diseases and establishing preclinical efficacy of novel therapies like Deep Brain Stimulation. A focal motor epilepsy model is described here. Method: Seizures were obtained after intracortical penicillin injection into the motor strip through a cannula in two awake monkeys and electrocorticograms were recorded by epidural screws. Seizures were analyzed and compared for number, average duration of each seizure and total duration of ictal activity. Pharmaco-resistance for antiepileptic drug was tested by administration of Diazepam during seizures. Results: A motor status with seizures mimicking those seen in Kojevnikov’s syndrome was easily generated several minutes after penicillin injection and lasted 24 h on an average. The model thus characterized appears stable and consistent. There is no significant variation between experiments in individual primate as well as between two specimens. Diazepam though reduced the total duration of seizures, failed to abolish behavioural seizures. Conclusion: This model represents a good alternative model for preclinical research aiming at testing novel therapies because seizures are obtained on demand, last up to 24 h after a single penicillin injection, are stable and resistant to Diazepam.展开更多
Sunlight represents the energy source for photosynthesis and plant growth. When growing in the field, plant photosynthesis has to manage strong fluctuations in light intensities. Regulation based on the thio- redoxin ...Sunlight represents the energy source for photosynthesis and plant growth. When growing in the field, plant photosynthesis has to manage strong fluctuations in light intensities. Regulation based on the thio- redoxin (Trx) system is believed to ensure light-responsive control of photosynthetic reactions in the chlo- roplast. However, direct evidence for a role of this system in regulating dynamic acclimation of photosyn- thesis in fluctuating conditions is largely lacking. In this report we show that the ferredoxin-dependent Trxs ml and m2 as well as the NADPH-dependent NTRC are both indispensable for photosynthetic acclimation in fluctuating light intensities. Arabidopsis mutants with combined deficiency in Trxs ml and m2 show wild- type growth and photosynthesis under constant light condition, while photosynthetic parameters are strongly modified in rapidly alternating high and low light. Two independent trxmlm2 mutants show lower photosynthetic efficiency in high light, but surprisingly significantly higher photosynthetic efficiency in low light. Our data suggest that a main target of Trx ml and m2 is the NADP-malate dehydrogenase involved in export of excess reductive power from the chloroplast. The decreased photosynthetic efficiency in the high-light peaks may thus be explained by a reduced capacity of the trxm lm2 mutants in the rapid light acti-vation of this enzyme. In the ntrc mutant, dynamic responses of non-photochemical quenching of excita- tion energy and plastoquinone reduction state both were strongly attenuated in fluctuating light intensities, leading to a massive decrease in PSII quantum efficiency and a specific decrease in plant growth under these conditions. This is likely due to the decreased ability of the ntrc mutant to control the stromal NADP(H) redox poise. Taken together, our results indicate that NTRC is indispensable in ensuring the full range of dynamic responses of photosynthesis to optimize photosynthesis and maintain growth in fluctu- ating light, while Trxs ml and m2 are indispensable for full activation of photosynthesis in the high-light pe- riods but negatively affect photosynthetic efficiency in the low-light periods of fluctuating light.展开更多
While the isotopic variations of barium were reported for the first time fourty years ago, the number of studies on barium isotopes significantly increased only after 2010. Barium isotope anomalies in meteorites have ...While the isotopic variations of barium were reported for the first time fourty years ago, the number of studies on barium isotopes significantly increased only after 2010. Barium isotope anomalies in meteorites have been successfully used to provide constraints about the origin of presolar Si C grains. In carbonaceous chondrites Ba isotope anomalies are indicative of the heterogeneity of the early solar system, possibly resulting from of a later injection of material after the cooling of solar system. Barium isotope fractionation in the same carbonaceous chondrites suggests that a strong magnetic field was present in the innermost part of the early solar system. Barium mass-dependent isotope fractionation has also been detected throughout Earth surface materials. While igneous rocks show limited Ba isotopic variations, relatively large isotopic variations are observed amongst and within soils, rivers, and biological materials. Indeed, plants seem to fractionate Ba isotopes during Ba uptake from soil solutions.Therefore, Ba isotope signatures have the potential to provide clues on the biological cycling of Ba at the Earth surface. In seawater, Ba isotopic variations have been mapped out, and are mainly related to barite precipitation, which is in turn related to organic matter remineralization in the water column.This makes Ba isotopes a potentially powerful tool to reconstruct past ocean productivity, although constraints are still lacking regarding the inputs of dissolved Ba to the oceans by rivers or hydrothermalism.展开更多
MicroRNAs (miRNAs) are evolu- tionarily conserved small non-coding RNA sequences, approximately 22 nucleotides in length, that act as negative regulators of target genes via binding to the 3'-untranslated region of...MicroRNAs (miRNAs) are evolu- tionarily conserved small non-coding RNA sequences, approximately 22 nucleotides in length, that act as negative regulators of target genes via binding to the 3'-untranslated region of mRNAs,展开更多
We present results of the synthesis of cobalt nanorods using the polyol process and the mechanism of magnetization reversal. We show that the nucleation step is significantly dependent on the nature of the ruthenium c...We present results of the synthesis of cobalt nanorods using the polyol process and the mechanism of magnetization reversal. We show that the nucleation step is significantly dependent on the nature of the ruthenium chloride used as the nucleating agent. This allows varying the diameter and aspect ratio of the cobalt nanorods independently. Co nanorods with aspect ratio, mean diameter, and mean length in the ranges ARm =3-16, Din= 7-25 nm, and Lm=30-300 nm, respectively, were produced using this method. X-ray diffraction and electron microscopy showed that a strong discrepancy between the structural coherence and morphological aspect ratio can exist because of stacking faults. The coercivity of assemblies of different nanorods was systematically measured, and the highest values were obtained for the smallest diameter and the largest structural coherence length. Micromagnetic simulations were performed to account for the dependence of the coercive field on the diameter. An important observation is that simple coherent magnetization rotation models do not apply to these magnetic nano-objects. Even for very small diameters (Dm = 5-10 nm) well below the theoretical coherent diameter Dcoh(CO)= 24 nm, we observed inhomogeneous reversal modes dominated by nucleation at the rod edges or at structural defects such as stacking faults. We conclude that, in order to produce high-coercivity materials based on nanowires, moderate aspect ratios of 5-10 are sufficient for providing a structural coherence similar to the morphological aspect ratio. Thus, the first priority should be to avoid the formation of stacking faults within the Co nanowires.展开更多
The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which ...The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which is involved in the elongation of the very long chain fatty acids,in muscle fibre formation.In humans and dogs,HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscleweakness.Throughanalysis of HACD1-deficient Labradors,Hacd1-knockout mice,and Hacd1-deficient myoblasts,we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration.We further demonstrate that in normal differentiating myoblasts,expression of the catalytically active HACD1 isoform,which is encoded by a muscle-enriched splice variant,yields decreased lysophosphatidylcholine content,a potent inhibitor of myoblast fusion,and increased concentrations of≥C18 and monounsaturated fatty acids of phospholipids.These lipid modifications correlate with a reduction in plasma membrane rigidity.In conclusion,we propose that fusion impairment constitutes a novel,non-exclusive pathological mechanism operating in congenital myopathies and reveal that HACD1 is a key regulator of a lipid-dependent muscle fibre growth mechanism.展开更多
文摘There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index (BMI). A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling (TUNEL) assay, we observed an increased rate of sDerm DNA damage in obese men (odds ratio (95% confidence interval): 2.5 (1.2-5.1)).
基金supported by the National Natural Science Foundation of China(Nos.11705103,12005120).
文摘As a proposed detector,the giant radio array for neutrino detection(GRAND)is primarily designed to discover and study the origin of ultra-high-energy cosmic rays,with ultra-high-energy neutrinos presenting the main method for detecting ultra-high-energy cosmic rays and their sources.The main principle is to detect radio emissions generated by ultra-high-energy neutrinos interacting with the atmosphere as they travel.GRAND is the largest neutrino detection array to be built in China.GRANDProto35,as the first stage of the GRAND experiment,is a coincidence array composed of radio antennas and a scintillation detector,the latter of which,as a traditional detector,is used to perform cross-validation with radio detection,thus verifying the radio detection efficiency and enabling study of the background exclusion method.This study focused on the implementation of the optimization simulation and experimental testing of the performance of the prototype scintillation detector used in GRANDProto35.A package based on GEANT4 was used to simulate the details of the scintillation detector,including the optical properties of its materials,the height of the light guide box,and position inhomogeneity.The surface of the scintillator and the reflective materials used in the detector was optimized,and the influence of light guide heights and position inhomogeneity on the energy and time resolutions of the detector was studied.According to the simulation study,the number of scintillator photoelectrons increased when changing from the polished surface to the ground surface,with the appropriate design height for the light guide box being 50 cm and the appropriate design area for the scintillator being 0.5 m^(2).The performance of the detector was tested in detail through a coincidence experiment,and the test results showed that the number of photoelectrons collected in the detector was$84 with a time resolution of~1 ns,indicating good performance.The simulation results were consistent with those obtained from the tests,which also verified the reliability of the simulation software.These studies provided a full understanding of the performance of the scintillation detector and guidance for the subsequent operation and analysis of the GRANDProto35 experimental array.
基金supported in part by a Peugeot SociétéAnonyme contract
文摘Gaseous naphthalene has been removed by air plasma generated by pulsed corona discharges at 100°C(LSPM)and dielectric barrier discharges(DBD)up to 250℃(LPGP)in different reactors geometries.Naphthalene has been chosen as one of unbumed hydrocarbon present in exhaust gas engine during the cold start of vehicles.The comparison between the different discharge geometries has been possible using the specific input energy(SIE)as relevant parameter for pollutant removal process control considering the differences in the electrical characteristics and the differences of gas flow.The best naphthalene degradation is obtained in the wire-to cylinder(WTC)corona discharge and the stem-to-cylinder DBD with an energy costβrespectively of 10 and 20 J L^-1.The main by-products issues of the naphthalene oxidation are CO2 and CO reaching 45%in Multi-Pin-to-Plan corona discharge.We detected polyaromatic hydrocarbons in the gas phase(few ppm)and in the solid phase deposited in the reactors.The introduction of water in the discharges promotes the naphthalene degradation by OH-atom,which has better oxidising power than O-atom in dry air.
基金This work was supported by the National Natural Science Foundation of China(Nos.11705103 and 12005120).
文摘Neutrino detection in the 100 PeV energy region is the ultimate means of studying the origin of ultra-highenergy cosmic rays,in which the large radio detection array giant radio array for neutrino detection(GRAND)project aims to use to decipher this century-old problem.The GRANDProto35 compact array is a microform of 35 radio prototype detectors for the GRAND experiment,which verifies the reliability of GRAND performance through operation,and data analysis of the prototype detectors.As radio detectors are a novel development in recent years,and their indexes need to be verified by traditional detectors,the GRAND Cooperation Group designed and constructed the GRANDProto35 coincidence array composed of radio detectors and scintillation detectors.This study simulated the changes in detection efficiency,effective area,and event rate of cosmic rays with zenith angle based on this coincidence array.The study found that the 1017 eV energy region is sensitive to GRANDProto35 detection.When the energy exceeded 1017 eV,the array detection efficiency could reach more than 95%and the effective area was up to*29106 m2.A simulation study on cosmic ray events with large zenith angles showed that the event rate detected by the array decreased significantly with increasing zenith angle,and the event rate of cosmic rays was approximately 0.1 per day for a zenith angle of 75.This serves as the background pollution rate for neutrino observation caused by largeangle cosmic-ray events,providing an important reference for further experiments.The study results will be verified after the joint operation of the coincidence array.
文摘We elaborate an error budget for the long-term accuracy of IGS(International Global Navigation Satellite System Service) polar motion estimates, concluding that it is probably about 25-30 μas(1-sigma)overall, although it is not possible to quantify possible contributions(mainly annual) that might transfer directly from aliases of subdaily rotational tide errors. The leading sources are biases arising from the need to align daily, observed terrestrial frames, within which the pole coordinates are expressed and which are continuously deforming, to the secular, linear international reference frame. Such biases are largest over spans longer than about a year. Thanks to the very large number of IGS tracking stations, the formal covariance errors are much smaller,around 5 to 10 μas. Large networks also permit the systematic frame-related errors to be more effectively minimized but not eliminated. A number of periodic errors probably also influence polar motion results, mainly at annual, GPS(Global Positioning System) draconitic, and fortnightly periods, but their impact on the overall error budget is unlikely to be significant except possibly for annual tidal aliases. Nevertheless, caution should be exercised in interpreting geophysical excitations near any of the suspect periods.
基金supported by the National Natural Science Foundation of China(Grant Nos.11533003,11673006,U1331202,U1931133 and U1938201)the Guangxi Science Foundation(2016GXNSFFA380006,AD17129006and 2018GXNSFGA281007)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB23040000)the Strategic Pioneer Program on Space Science,Chinese Academy of Sciences(XDA15052600)financial support from the Chinese Academy of Sciences PIFI post-doctoral fellowship program(program C)financial support of the Univ Earth S Labex program at Sorbonne Paris Cité(ANR-10-LABX-0023 and ANR-11-IDEX-0005-02)
文摘The second(O2)observational campaign of gravitational waves(GWs)organized by the LIGO/Virgo Collaborations has led to several breakthroughs such as the detection of GW signals from merger systems involving black holes or neutrons stars.During O2,14 GW alerts were sent to the astronomical community with sky regions mostly covering over hundreds of square degrees.Among them,six were finally confirmed as real astrophysical events.Since 2013,a new set of ground-based robotic telescopes called Ground-based Wide Angle Camera system(GWAC)project and its pathfinder mini-GWAC has been developed to contribute to the various challenges of multi-messenger and time domain astronomy.The GWAC system is built up in the framework of the ground-segment system of the SVOM mission that will be devoted to the study of the multi-wavelength transient sky in the next decade.During O2,only the mini-GWAC telescope network was fully operational.Due to the wide field of view and fast automatic follow-up capabilities of the mini-GWAC telescopes,they were adept to efficiently cover the sky localization areas of GW event candidates.In this paper,we present the mini-GWAC pipeline we have set up to respond to GW alerts and we report our optical follow-up observations of eight GW alerts detected during the O2 run.Our observations provided the largest coverage of the GW localization areas with a short latency made by any optical facility.We found tens of optical transient candidates in our images,but none of those could be securely associated with any confirmed black hole-black hole merger event.Based on this first experience and the near future technical improvements of our network system,we will be more competitive in detecting the optical counterparts from some GW events that will be identified during the upcoming O3 run,especially those emerging from binary neutron star mergers.
基金financial support from IPGP as part of the IEPT RAS-IPGP cooperation.IPGP Contribution NS 3391.
文摘We investigate global temperature data produced by the Climate Research Unit at the University of East Anglia (CRU) and the Berkeley Earth Surface Temperature consortium (BEST). We first fit the 1850-2010 data with polynomials of degrees 1 to 9. A significant ~60-yr oscillation is accounted for as soon as degree 4 is reached. This oscillation is even better modeled as a broken line, more precisely a series of ~30-yr long linear segments, with slope breaks (singularities) in ~1904, ~1940, and ~1974 (±3 yr), and a possible recent occurrence at the turn of the 20th century. Oceanic indices PDO (Pacific Decadal Oscillation) and AMO (Atlantic Multidecadal Oscillation) have undergone major changes (respectively of sign and slope) roughly at the same times as the temperature slope breaks. This can be interpreted with a system of oceanic non-linear coupled oscillators with abrupt mode shifts. Thus, the Earth’s climate may have entered a new mode (a new ~30-yr episode) near the turn of the 20th century: no further temperature increase, a dominantly negative PDO index and a decreasing AMO index might be expected for the next decade or two.
文摘In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance (EAS) exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action (MOA) of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool (together with the epidemiological approach) for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.
基金supported by the Programme Blanc de l’Agence National de la Recherche.
文摘Family-based tests of association between a genetic marker and a disease constitute a common design to dissect the genetic architecture of complex traits. The FBAT software is one of the most popular tools to perform such studies. However, researchers are also often interested in the genetic contribution to a more specific manifestation of the phenotype (e.g. severe vs. non-severe form) known as a secondary outcome. Here, what we demonstrate is the limited power of the classical formulation of the FBAT statistic to detect the effect of genetic variants that influence a secondary outcome, in particular when these variants also impact on the onset of the disease, the primary outcome. We prove that this loss of power is driven by an implicit hypothesis, and we propose a derivation of the original FBAT statistic, free from this implicit hypothesis. Finally, we demonstrate analytically that our new statistic is robust and more powerful than FBAT for the detection of association between a genetic variant and a secondary outcome.
文摘A patient treated with a vitamin K antagonist (VKA) since the implantation of two mechanical heart valves developed acute anemia after the extraction of a tooth. This case report and data in the literature indicate a need for specific measures before, during, and after oral surgery in patients taking anticoagulant therapy: 1) the bleeding risk should be evaluated before the procedure. The INR should be measured routinely, 2) the procedure should be scheduled early in the week to allow an evaluation at the fibrinolysis peak, i.e., 48 to 72 hours after surgery, which is the time of greatest risk of delayed bleeding, 3) the surgical procedure should be appropriate for the elevated bleeding risk, 4) postoperative monitoring is of the most importance, as bleeding is usually delayed in patients on VKA therapy, 5) when poor treatment adherence is expected, day-hospital admission is useful to ensure that the postoperative protocol is implemented properly and to detect early bleeding. The treatment of post-extraction acute anemia includes local hemostasis protocol with the revision of the socket followed by red-blood-cell pack transfusion. A daily fluindione dosage control, and a normal hemoglobin level will allow the patient to leave the hospital.
文摘In order to study social inequalities, indices can be used to summarize the multiple dimensions of the socioeconomic status. As a part of the Equit’Area Project, a public health program focused on social and environmental health inequalities;a statistical procedure to create (neighborhood) socioeconomic indices was developed. This procedure uses successive principal components analyses to select variables and create the index. In order to simplify the application of the procedure for non-specialists, the R package SesIndexCreatoR was created. It allows the creation of the index with all the possible options of the procedure, the classification of the resulting index in categories using several classical methods, the visualization of the results, and the generation of automatic reports.
基金supported by“Fondation de l’avenir”and Medtronic Europe.
文摘Background and objective: Generating and characterizing primate models of epileptic seizures are important for understanding pathophysiology of diseases and establishing preclinical efficacy of novel therapies like Deep Brain Stimulation. A focal motor epilepsy model is described here. Method: Seizures were obtained after intracortical penicillin injection into the motor strip through a cannula in two awake monkeys and electrocorticograms were recorded by epidural screws. Seizures were analyzed and compared for number, average duration of each seizure and total duration of ictal activity. Pharmaco-resistance for antiepileptic drug was tested by administration of Diazepam during seizures. Results: A motor status with seizures mimicking those seen in Kojevnikov’s syndrome was easily generated several minutes after penicillin injection and lasted 24 h on an average. The model thus characterized appears stable and consistent. There is no significant variation between experiments in individual primate as well as between two specimens. Diazepam though reduced the total duration of seizures, failed to abolish behavioural seizures. Conclusion: This model represents a good alternative model for preclinical research aiming at testing novel therapies because seizures are obtained on demand, last up to 24 h after a single penicillin injection, are stable and resistant to Diazepam.
文摘Sunlight represents the energy source for photosynthesis and plant growth. When growing in the field, plant photosynthesis has to manage strong fluctuations in light intensities. Regulation based on the thio- redoxin (Trx) system is believed to ensure light-responsive control of photosynthetic reactions in the chlo- roplast. However, direct evidence for a role of this system in regulating dynamic acclimation of photosyn- thesis in fluctuating conditions is largely lacking. In this report we show that the ferredoxin-dependent Trxs ml and m2 as well as the NADPH-dependent NTRC are both indispensable for photosynthetic acclimation in fluctuating light intensities. Arabidopsis mutants with combined deficiency in Trxs ml and m2 show wild- type growth and photosynthesis under constant light condition, while photosynthetic parameters are strongly modified in rapidly alternating high and low light. Two independent trxmlm2 mutants show lower photosynthetic efficiency in high light, but surprisingly significantly higher photosynthetic efficiency in low light. Our data suggest that a main target of Trx ml and m2 is the NADP-malate dehydrogenase involved in export of excess reductive power from the chloroplast. The decreased photosynthetic efficiency in the high-light peaks may thus be explained by a reduced capacity of the trxm lm2 mutants in the rapid light acti-vation of this enzyme. In the ntrc mutant, dynamic responses of non-photochemical quenching of excita- tion energy and plastoquinone reduction state both were strongly attenuated in fluctuating light intensities, leading to a massive decrease in PSII quantum efficiency and a specific decrease in plant growth under these conditions. This is likely due to the decreased ability of the ntrc mutant to control the stromal NADP(H) redox poise. Taken together, our results indicate that NTRC is indispensable in ensuring the full range of dynamic responses of photosynthesis to optimize photosynthesis and maintain growth in fluctu- ating light, while Trxs ml and m2 are indispensable for full activation of photosynthesis in the high-light pe- riods but negatively affect photosynthetic efficiency in the low-light periods of fluctuating light.
基金funding from the European Research Council under the H2020 framework program/ERC grant agreement (No.637503) (Pristine)the financial support of the Univ Earth S Labex program at Sorbonne Paris Cité (ANR-10LABX-0023 and ANR-11-IDEX-0005-02)+3 种基金the ANR through a chaire d’excellence Sorbonne Paris Citésupported by IPGP multidisciplinary program PARIby Region lle-de-France SESAME (No. 12015908)funded by the French Ministry for Higher Education and Research.This is IPGP contribution 3913
文摘While the isotopic variations of barium were reported for the first time fourty years ago, the number of studies on barium isotopes significantly increased only after 2010. Barium isotope anomalies in meteorites have been successfully used to provide constraints about the origin of presolar Si C grains. In carbonaceous chondrites Ba isotope anomalies are indicative of the heterogeneity of the early solar system, possibly resulting from of a later injection of material after the cooling of solar system. Barium isotope fractionation in the same carbonaceous chondrites suggests that a strong magnetic field was present in the innermost part of the early solar system. Barium mass-dependent isotope fractionation has also been detected throughout Earth surface materials. While igneous rocks show limited Ba isotopic variations, relatively large isotopic variations are observed amongst and within soils, rivers, and biological materials. Indeed, plants seem to fractionate Ba isotopes during Ba uptake from soil solutions.Therefore, Ba isotope signatures have the potential to provide clues on the biological cycling of Ba at the Earth surface. In seawater, Ba isotopic variations have been mapped out, and are mainly related to barite precipitation, which is in turn related to organic matter remineralization in the water column.This makes Ba isotopes a potentially powerful tool to reconstruct past ocean productivity, although constraints are still lacking regarding the inputs of dissolved Ba to the oceans by rivers or hydrothermalism.
文摘MicroRNAs (miRNAs) are evolu- tionarily conserved small non-coding RNA sequences, approximately 22 nucleotides in length, that act as negative regulators of target genes via binding to the 3'-untranslated region of mRNAs,
文摘We present results of the synthesis of cobalt nanorods using the polyol process and the mechanism of magnetization reversal. We show that the nucleation step is significantly dependent on the nature of the ruthenium chloride used as the nucleating agent. This allows varying the diameter and aspect ratio of the cobalt nanorods independently. Co nanorods with aspect ratio, mean diameter, and mean length in the ranges ARm =3-16, Din= 7-25 nm, and Lm=30-300 nm, respectively, were produced using this method. X-ray diffraction and electron microscopy showed that a strong discrepancy between the structural coherence and morphological aspect ratio can exist because of stacking faults. The coercivity of assemblies of different nanorods was systematically measured, and the highest values were obtained for the smallest diameter and the largest structural coherence length. Micromagnetic simulations were performed to account for the dependence of the coercive field on the diameter. An important observation is that simple coherent magnetization rotation models do not apply to these magnetic nano-objects. Even for very small diameters (Dm = 5-10 nm) well below the theoretical coherent diameter Dcoh(CO)= 24 nm, we observed inhomogeneous reversal modes dominated by nucleation at the rod edges or at structural defects such as stacking faults. We conclude that, in order to produce high-coercivity materials based on nanowires, moderate aspect ratios of 5-10 are sufficient for providing a structural coherence similar to the morphological aspect ratio. Thus, the first priority should be to avoid the formation of stacking faults within the Co nanowires.
基金This work was supported by the Agence Nationale de la Recherche(ANR-12-JSV1-0005)the Association Franc¸aise contre les Myopathies(14577,15882,and 16143)+4 种基金the CNM Project(www.labradorcnm.com)the Alliance program(22866ZM)the Myotubular Trust and Grants-in-Aid for Scientific Research(B)to A.K.from Japan Society for the Promotion of Science(23370057)J.B.was supported by the French Ministry of Research and Technologies and the Universite´Paris 6(Paris)V.G.,A.P.,and A.R.were supported by the ANR,N.B-G.and I.B.were supported by the AFM,and G.W.was supported by the BBSRC CASE and the Myotubular Trust.
文摘The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which is involved in the elongation of the very long chain fatty acids,in muscle fibre formation.In humans and dogs,HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscleweakness.Throughanalysis of HACD1-deficient Labradors,Hacd1-knockout mice,and Hacd1-deficient myoblasts,we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration.We further demonstrate that in normal differentiating myoblasts,expression of the catalytically active HACD1 isoform,which is encoded by a muscle-enriched splice variant,yields decreased lysophosphatidylcholine content,a potent inhibitor of myoblast fusion,and increased concentrations of≥C18 and monounsaturated fatty acids of phospholipids.These lipid modifications correlate with a reduction in plasma membrane rigidity.In conclusion,we propose that fusion impairment constitutes a novel,non-exclusive pathological mechanism operating in congenital myopathies and reveal that HACD1 is a key regulator of a lipid-dependent muscle fibre growth mechanism.