By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ej...By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 December 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.展开更多
A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Pote...A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Potential.The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy.It is shown that Exergy Analysis itself is a valuable tool in energy integration.Within the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving profitability.The present results are discussed under the optimistic hope that they may help to define new energy and environmental policies.展开更多
The study PV/diesel system is a stand-alone microgrid powered by the PV/diesel combination without production storage. The study focused on optimising PV/diesel production by monitoring data. It also referred to a com...The study PV/diesel system is a stand-alone microgrid powered by the PV/diesel combination without production storage. The study focused on optimising PV/diesel production by monitoring data. It also referred to a comparison of sensitive factors in PV/diesel production. This study implemented structural and non-structural factors of the said system. A literature search was conducted to determine the factors involved. So, factors such as system autonomy, energy quality, system stability and data monitoring were considered for the study. Thus, after a detailed presentation of the data monitoring, a comparison based on the method, Analysis of Failure Modes, their Effects and Criticalities (FMEA) was carried out. At the end of the comparison, a hierarchy of parameters in the exploitation of the energy production of autonomous microgrids was made. From its results, it emerges a good consideration of the factor “data monitoring” in the management of the system studied. The results obtained confirm the importance of data monitoring for a better optimization of energy production. A monitoring program or procedure has been developed according to the originality that the present study has identified. The study also made it possible to evaluate the performance of data monitoring for the energy production of photovoltaic systems in general and hybrid PV/diesel systems in particular.展开更多
Introduction. - X-linked adrenoleukodystrophy (ALD) is the most frequent type of leukodystrophy (1/17 000 males). The phenotypic range in male patients varies from the severe cerebral presentations in children to the ...Introduction. - X-linked adrenoleukodystrophy (ALD) is the most frequent type of leukodystrophy (1/17 000 males). The phenotypic range in male patients varies from the severe cerebral presentations in children to the milder myeloneuropathy and to isolate adrenal insufficiency. More than a half of the carrier females display clinical symptoms over the age of 40 years. Observation. - Diagnosis of ALD was raised in a 40 year-old female who presented with spastic paraparesis and sphincterian dysfunction, occurring after the delivery of her first child. There was no family history of ALD. Very long-chain fatty acids (VLCFA) were assayed in her one-year-old son in order to propose appropriate hormonal and neurological survey. His dosage was abnormal and an adrenal insufficiency was subsequently found. A brain MRI will be proposed biannually when he reaches to age of for years. The proband’s mother had an increased level of VLCFA, showing that she was a carrier. Family screening was extended to the proband’s sisters and maternal aunt who already had children, but also to her brother, who may express a mild form of the disease later on, and to her maternal uncles who might be asymptomatic carriers. A frameshift mutation was found in the ABCD1 gene and will allow accurate carrier identification and prenatal diagnosis in the family. Conclusion. - ALD diagnosis should be evoked in a woman affected by myelopathy despite the lack of family history. Such a diagnosis has severe consequences since some of the related males may carry the mutation although they do not display any symptom at time of diagnosis, and because carrier females have a risk to both have a clinical expression of the disease and give birth to an affected boy.展开更多
The effects of hydrodynamic anisotropy on the mixed-convection in a vertical porous channel heated on its plates with a thermal radiation are investigated analytically for fully developed flow regime. The porous mediu...The effects of hydrodynamic anisotropy on the mixed-convection in a vertical porous channel heated on its plates with a thermal radiation are investigated analytically for fully developed flow regime. The porous medium is anisotropic in permeability whose principal axes are oriented in a direction that is oblique to the gravity. The generalized Brinkman-extended Darcy model which allows the no-slip boundary-condition on solid wall is used in the formulation of the problem. The flow reversal, the thermal radiation influence for natural, and forced convection are considered in the limiting cases for low and high porosity media. It was found that the anisotropic permeability ratio, the orientation angle of the principal axes of permeability and the radiation parameter affected significantly the flow regime and the heat transfer.展开更多
The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined...The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microscopy performed in backscattered electron mode. The embedded particles distribution was shown to be the densest and the most uniform in laminar low flow mode and when the nozzle is at a distance of 5 mm close from the cathode. Excrescences observed on the composite surface are due to the wave-like flow of the jet on the cathode surface. The silica content of the nickel composite coatings was assessed by energy dispersive X-ray spectroscopy. The amount of particles embedded in the coating decreases with an increasing Reynolds number and as the nozzle-to-sample distance d becomes larger. A maximum rate of 4.43 wt% of silica has been successfully loaded at a distance d equal to 5 mm in the Ni-SiO2 composite coating.展开更多
The onset of thermal convection, due to heating from below in a system consisting of a fluid layer overlying a porous layer with anisotropic permeability and thermal diffusivity, is investigated analytically. The poro...The onset of thermal convection, due to heating from below in a system consisting of a fluid layer overlying a porous layer with anisotropic permeability and thermal diffusivity, is investigated analytically. The porous medium is both anisotropic in permeability whose principal axes are oriented in a direction that is oblique to the gravity vector and in thermal conductivity with principal directions coincident with the coordinate axes. The Beavers-Joseph condition is applied at the interface between the two layers. Based on parallel flow approximation theory, a linear stability analysis is conducted to study the geothermal river beds system and documented the effects of the physical parameters describing the problem. The critical Rayleigh numbers for both the fluid and porous layers corresponding, to the onset of convection arising from sudden heating and cooling at the boundaries are also predicted. The results obtained are in agreement with those found in the past for particular isotropic and anisotropic cases and for limiting cases concerning pure porous media and for pure fluid layer. It has demonstrated that the effects of anisotropic parameters are highly significant.展开更多
AIM: To find the point mutations meaningful for inactivationof liver-related putative tumor suppressor gene (LPTS) gene,a human novel liver-related putative tumor suppressor geneand telomerase inhibitor in hepatocellu...AIM: To find the point mutations meaningful for inactivationof liver-related putative tumor suppressor gene (LPTS) gene,a human novel liver-related putative tumor suppressor geneand telomerase inhibitor in hepatocellular carcinoma.METHODS: The entire coding sequence of LPTS genewas examined for mutations by single strand conformationpolymorphism (SSCP) assay and PCR products directsequencing in 56 liver cancer cell lines, 7 ovarian cancerand 7 head & neck tumor cell lines and 70 pairs of HCCtissues samples. The cDNA fragment coding for the mostfrequent mutant protein was subcloned into GST fusionexpression vector. The product was expressed in E. coliand purified by glutathione-agarose column. Telomericrepeat amplification protocol (TRAP) assays wereperformed to study the effect of point mutation totelomerase inhibitory activity.RESULTS: SSCP gels showed the abnormal shifting bandsand DNA sequencing found that there were 5 differentmutations and/or polymorphisms in 12 tumor cell lineslocated at exon2, exon5 and exon7. The main alterationswere A(778)A/G and A(880)T in exon7. The change in siteof 778 could not be found in HCC tissue samples, while themutation in position 880 was seen in 7 (10 %) cases. Themutation in the site of 880 had no effect on telomeraseinhibitory activity.CONCLUSION: Alterations identified in this study arepolymorphisms of LPTS gene. LPTS mutations occur in HCCbut are infrequent and of little effect on the telomeraseinhibitory function of the protein. Epigenetics, such asmethylation, acetylation, may play the key role in inactivationof LPTS.展开更多
The plant steroid hormones, brassinosteroids （BRs）, and their precursors, phytosterols, play major roles in plant growth, development, and stress tolerance. Here, we review the impressive progress made during recent...The plant steroid hormones, brassinosteroids （BRs）, and their precursors, phytosterols, play major roles in plant growth, development, and stress tolerance. Here, we review the impressive progress made during recent years in elucidating the components of the sterol and BR metabolic and signaling pathways, and in understanding their mecha- nism of action in both model plants and crops, such as Arabidopsis and rice. We also discuss emerging insights into the regulations of these pathways, their interactions with other hormonal pathways and multiple environmental signals, and the putative nature of sterols as signaling molecules.展开更多
Cyclin A2 is an essential regulator of the cell division cycle through the activation of kinases that participate to the regulation of S phase as well as the mitotic entry. However,whereas its degradation by the prote...Cyclin A2 is an essential regulator of the cell division cycle through the activation of kinases that participate to the regulation of S phase as well as the mitotic entry. However,whereas its degradation by the proteasome in mid mitosis was thought to be essential for mitosis to proceed,recent observations show that a small fraction of cyclin A2 persists beyond metaphase and is degraded by autophagy. Its implication in the control of cytoskeletal dynamics and cell movement has unveiled its role in the modulation of Rho A activity. Since this GTPase is involved in both cell rounding early in mitosis and later,in the formation of the cleavage furrow,this suggests that cyclin A2 is a novel actor in cytokinesis. Taken together,these data point to this cyclin as a potential mediator of cell-niche interactions whose dysregulation could be taken as a hallmark of metastasis.展开更多
文摘By analysing a long series of data (1996-2019), we show that solar cycle 23 was more marked by violent solar flares and coronal mass ejections (CMEs) compared to solar cycle 24. In particular, the halo coronal mass ejections associated with X-class flares appear to be among the most energetic events in solar activity given the size of the flares, the speed of the CMEs and the intense geomagnetic storms they produce. Out of eighty-six (86) X-class halo CMEs, thirty-seven (37) or 43% are highly geoeffective;twenty-four (24) or approximately 28% are moderately geoeffective and twenty-five (25) or 29% are not geoeffective. Over the two solar cycles (1996 to 2019), 71% of storms were geoeffective and 29% were not. For solar cycle 23, about 78% of storms were geoeffective, while for solar cycle 24, about 56% were geoeffective. For the statistical study based on speed, 85 halo CMEs associated with X-class flares were selected because the CME of 6 December 2006 has no recorded speed value. For both solar cycles, 75.29% of the halo CMEs associated with X-class flares have a speed greater than 1000 km/s. The study showed that 42.18% of halo (X) CMEs with speeds above 1000 km/s could cause intense geomagnetic disturbances. These results show the contribution (in terms of speed) of each class of halo (X) CMEs to the perturbation of the Earth’s magnetic field. Coronal mass ejections then become one of the key indicators of solar activity, especially as they affect the Earth.
文摘A hybrid heat pump(compression/absorption)with an integrated thermal photovoltaic unit is studied.The considered working fluids are organic mixtures:R245fa/DMAC and R236fa/DMAC,chosen for their low Global Warming Potential.The main objective is the optimization of energy efficiency in order to minimize the environmental impact through the implementation of a sustainable strategy.It is shown that Exergy Analysis itself is a valuable tool in energy integration.Within the imposed framework of minimizing total annual costs,entropy analysis can be instrumental in determining the optimal plant concept,optimizing energy conversion and use,and improving profitability.The present results are discussed under the optimistic hope that they may help to define new energy and environmental policies.
文摘The study PV/diesel system is a stand-alone microgrid powered by the PV/diesel combination without production storage. The study focused on optimising PV/diesel production by monitoring data. It also referred to a comparison of sensitive factors in PV/diesel production. This study implemented structural and non-structural factors of the said system. A literature search was conducted to determine the factors involved. So, factors such as system autonomy, energy quality, system stability and data monitoring were considered for the study. Thus, after a detailed presentation of the data monitoring, a comparison based on the method, Analysis of Failure Modes, their Effects and Criticalities (FMEA) was carried out. At the end of the comparison, a hierarchy of parameters in the exploitation of the energy production of autonomous microgrids was made. From its results, it emerges a good consideration of the factor “data monitoring” in the management of the system studied. The results obtained confirm the importance of data monitoring for a better optimization of energy production. A monitoring program or procedure has been developed according to the originality that the present study has identified. The study also made it possible to evaluate the performance of data monitoring for the energy production of photovoltaic systems in general and hybrid PV/diesel systems in particular.
文摘Introduction. - X-linked adrenoleukodystrophy (ALD) is the most frequent type of leukodystrophy (1/17 000 males). The phenotypic range in male patients varies from the severe cerebral presentations in children to the milder myeloneuropathy and to isolate adrenal insufficiency. More than a half of the carrier females display clinical symptoms over the age of 40 years. Observation. - Diagnosis of ALD was raised in a 40 year-old female who presented with spastic paraparesis and sphincterian dysfunction, occurring after the delivery of her first child. There was no family history of ALD. Very long-chain fatty acids (VLCFA) were assayed in her one-year-old son in order to propose appropriate hormonal and neurological survey. His dosage was abnormal and an adrenal insufficiency was subsequently found. A brain MRI will be proposed biannually when he reaches to age of for years. The proband’s mother had an increased level of VLCFA, showing that she was a carrier. Family screening was extended to the proband’s sisters and maternal aunt who already had children, but also to her brother, who may express a mild form of the disease later on, and to her maternal uncles who might be asymptomatic carriers. A frameshift mutation was found in the ABCD1 gene and will allow accurate carrier identification and prenatal diagnosis in the family. Conclusion. - ALD diagnosis should be evoked in a woman affected by myelopathy despite the lack of family history. Such a diagnosis has severe consequences since some of the related males may carry the mutation although they do not display any symptom at time of diagnosis, and because carrier females have a risk to both have a clinical expression of the disease and give birth to an affected boy.
文摘The effects of hydrodynamic anisotropy on the mixed-convection in a vertical porous channel heated on its plates with a thermal radiation are investigated analytically for fully developed flow regime. The porous medium is anisotropic in permeability whose principal axes are oriented in a direction that is oblique to the gravity. The generalized Brinkman-extended Darcy model which allows the no-slip boundary-condition on solid wall is used in the formulation of the problem. The flow reversal, the thermal radiation influence for natural, and forced convection are considered in the limiting cases for low and high porosity media. It was found that the anisotropic permeability ratio, the orientation angle of the principal axes of permeability and the radiation parameter affected significantly the flow regime and the heat transfer.
文摘The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microscopy performed in backscattered electron mode. The embedded particles distribution was shown to be the densest and the most uniform in laminar low flow mode and when the nozzle is at a distance of 5 mm close from the cathode. Excrescences observed on the composite surface are due to the wave-like flow of the jet on the cathode surface. The silica content of the nickel composite coatings was assessed by energy dispersive X-ray spectroscopy. The amount of particles embedded in the coating decreases with an increasing Reynolds number and as the nozzle-to-sample distance d becomes larger. A maximum rate of 4.43 wt% of silica has been successfully loaded at a distance d equal to 5 mm in the Ni-SiO2 composite coating.
文摘The onset of thermal convection, due to heating from below in a system consisting of a fluid layer overlying a porous layer with anisotropic permeability and thermal diffusivity, is investigated analytically. The porous medium is both anisotropic in permeability whose principal axes are oriented in a direction that is oblique to the gravity vector and in thermal conductivity with principal directions coincident with the coordinate axes. The Beavers-Joseph condition is applied at the interface between the two layers. Based on parallel flow approximation theory, a linear stability analysis is conducted to study the geothermal river beds system and documented the effects of the physical parameters describing the problem. The critical Rayleigh numbers for both the fluid and porous layers corresponding, to the onset of convection arising from sudden heating and cooling at the boundaries are also predicted. The results obtained are in agreement with those found in the past for particular isotropic and anisotropic cases and for limiting cases concerning pure porous media and for pure fluid layer. It has demonstrated that the effects of anisotropic parameters are highly significant.
基金a grant from National High Technology"863"Program of China,No.2001AA221021a grant from Special Funds for Major State Basic Research"973"of China,No.001CB510205+1 种基金a grant from the National Natural Sciences Foundation of China,No.30170524Chine-France PRA dans le domaine de la Biologie 2001.No.PRA B 01-05
文摘AIM: To find the point mutations meaningful for inactivationof liver-related putative tumor suppressor gene (LPTS) gene,a human novel liver-related putative tumor suppressor geneand telomerase inhibitor in hepatocellular carcinoma.METHODS: The entire coding sequence of LPTS genewas examined for mutations by single strand conformationpolymorphism (SSCP) assay and PCR products directsequencing in 56 liver cancer cell lines, 7 ovarian cancerand 7 head & neck tumor cell lines and 70 pairs of HCCtissues samples. The cDNA fragment coding for the mostfrequent mutant protein was subcloned into GST fusionexpression vector. The product was expressed in E. coliand purified by glutathione-agarose column. Telomericrepeat amplification protocol (TRAP) assays wereperformed to study the effect of point mutation totelomerase inhibitory activity.RESULTS: SSCP gels showed the abnormal shifting bandsand DNA sequencing found that there were 5 differentmutations and/or polymorphisms in 12 tumor cell lineslocated at exon2, exon5 and exon7. The main alterationswere A(778)A/G and A(880)T in exon7. The change in siteof 778 could not be found in HCC tissue samples, while themutation in position 880 was seen in 7 (10 %) cases. Themutation in the site of 880 had no effect on telomeraseinhibitory activity.CONCLUSION: Alterations identified in this study arepolymorphisms of LPTS gene. LPTS mutations occur in HCCbut are infrequent and of little effect on the telomeraseinhibitory function of the protein. Epigenetics, such asmethylation, acetylation, may play the key role in inactivationof LPTS.
文摘The plant steroid hormones, brassinosteroids （BRs）, and their precursors, phytosterols, play major roles in plant growth, development, and stress tolerance. Here, we review the impressive progress made during recent years in elucidating the components of the sterol and BR metabolic and signaling pathways, and in understanding their mecha- nism of action in both model plants and crops, such as Arabidopsis and rice. We also discuss emerging insights into the regulations of these pathways, their interactions with other hormonal pathways and multiple environmental signals, and the putative nature of sterols as signaling molecules.
基金Supported by Agence Nationale de la Recherche(08-BLAN-0037-02),Fondation ARC pour la Recherche sur le Cancerand Gefluc+2 种基金CNRS/Région Languedoc-Roussillon and Fondation pour la Recherche Médicale(Loukil A)the French Ministry of Education and Research and Fondation pour la Recherche Médicale(Bendris N)the Canadian Institutes of Health Research,La Ligue Contre le Cancer and the Fondation de France(Cheung CT)
文摘Cyclin A2 is an essential regulator of the cell division cycle through the activation of kinases that participate to the regulation of S phase as well as the mitotic entry. However,whereas its degradation by the proteasome in mid mitosis was thought to be essential for mitosis to proceed,recent observations show that a small fraction of cyclin A2 persists beyond metaphase and is degraded by autophagy. Its implication in the control of cytoskeletal dynamics and cell movement has unveiled its role in the modulation of Rho A activity. Since this GTPase is involved in both cell rounding early in mitosis and later,in the formation of the cleavage furrow,this suggests that cyclin A2 is a novel actor in cytokinesis. Taken together,these data point to this cyclin as a potential mediator of cell-niche interactions whose dysregulation could be taken as a hallmark of metastasis.
