Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expan...Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expansion in southeastern Brazil whereas the impact of sugarcane expansion over areas of soybean plantation in previous Cerrado biome is still unknown. However, the expansion of sugarcane production in the state of S?o Paulohas been shown to cause an increase in the local abundance of rodents and result in the emergence of infectious diseases such as hantaviruses and leptospirosis in humans. In addition, with an increase in the use of agrochemicals there will be an increase in euthrophication of watercourses and soil pollution. Considering that S?o Paulo has a population of approximately 40 million people, these local impacts are relevant. Environmental law should be improved and enforced in Brazil to ensure that sugarcane production is not only economically profitable but also environmentally responsible.展开更多
In this work,we are concerned with numerical approximation of the gyroaverage operators arising in plasma physics to take into account the effects of the finite Larmor radius corrections.Several methods are proposed i...In this work,we are concerned with numerical approximation of the gyroaverage operators arising in plasma physics to take into account the effects of the finite Larmor radius corrections.Several methods are proposed in the space configuration and compared to the reference spectral method.We then investigate the influence of the different approximations considering the coupling with some guiding-center models available in the literature.展开更多
In this report,a charge preserving numerical resolution of the 1D VlasovAmp`ere equation is achieved,with a forward Semi-Lagrangian method introduced in[10].The Vlasov equation belongs to the kinetic way of simulating...In this report,a charge preserving numerical resolution of the 1D VlasovAmp`ere equation is achieved,with a forward Semi-Lagrangian method introduced in[10].The Vlasov equation belongs to the kinetic way of simulating plasmas evolution,and is coupled with the Poisson’s equation,or equivalently under charge conservation,the Amp`ere’s one,which self-consistently rules the electric field evolution.In order to ensure having proper physical solutions,it is necessary that the scheme preserves charge numerically.B-spline deposition will be used for the interpolation step.The solving of the characteristics will be made with a Runge-Kutta 2 method and with a Cauchy-Kovalevsky procedure.展开更多
We study the number of solutions N(B,F) of the diophantine equation n1n2 = n3n4,where 1 ≤ n1≤B, 1≤ n3 ≤B, n2, n4 ∈ F and F C [1, B] is a factor closed set. We study more particularly the case when F = {m = p1^...We study the number of solutions N(B,F) of the diophantine equation n1n2 = n3n4,where 1 ≤ n1≤B, 1≤ n3 ≤B, n2, n4 ∈ F and F C [1, B] is a factor closed set. We study more particularly the case when F = {m = p1^ε1…pk^εk ,εj∈ {0, 1}, 1≤ j ≤ k}, p1,… ,pk being distinct prime numbers.展开更多
In this paper,we study high order discretization methods for solving the Maxwell equations on hybrid triangle-quad meshes.We have developed high order finite edge element methods coupled with different high order time...In this paper,we study high order discretization methods for solving the Maxwell equations on hybrid triangle-quad meshes.We have developed high order finite edge element methods coupled with different high order time schemes and we compare results and efficiency for several schemes.We introduce in particular a class of simple high order low dissipation time schemes based on a modified Taylor expansion.展开更多
Objective:Nutraceutical products are widely used for their claimed therapeutic benefits.However,falsified or adulterated nutraceuticals present a major health threat to consumers.This study investigates the pharmaceut...Objective:Nutraceutical products are widely used for their claimed therapeutic benefits.However,falsified or adulterated nutraceuticals present a major health threat to consumers.This study investigates the pharmaceutical quality,safety and anti-inflammatory effects of six male enhancement nutraceuticals that claim to be 100%natural.Methods:Three batches of six male enhancement products were tested to detect the presence and levels of adulterants via high-performance liquid chromatography(HPLC).The pharmaceutical quality of the selected nutraceuticals was tested with near infrared spectroscopy(NIR)and Se De M.The cytotoxic effects of these products on HepG2 cells were determined through cell proliferation(XTT)and lactate dehydrogenase(LDH)cytotoxicity assays.Lastly,the in vitro inflammatory effects of these products were investigated using murine J774 macrophages through cytokine release analysis.Results:HPLC analysis detected the presence of sildenafil citrate,a vasodilator,and the active ingredient in Viagra and Revatio,in all batches of the products we analyzed.Amount of sildenafil citrate ranged from 0.45 mg to 51.85 mg among different batches.NIR assessment showed inter-and intra-batch heterogeneity in product composition.Results of the XTT and LDH assays showed significant cytotoxic effects of the analyzed products.XTT analysis revealed that the viability of HepG2 treated with tested products varied from 27.57%to 41.43%.Interestingly,the male enhancement products also showed anti-inflammatory effects.Conclusion:Despite their labeling as 100%natural,all products tested in this study contained levels of sildenafil citrate,which was not reported on the packaging.There was a lack of pharmaceutical uniformity among products of the same batch and across different batches.Additionally,the products we tested had cytotoxic effects.These study findings highlight the adulteration,poor quality and hazard of these nutraceuticals.Therefore,strict regulation of these products and standardization of the definition of nutraceuticals are urgently needed.Further,these falsely advertised products should be withdrawn from the market due to potential adverse effects on the health of their consumers.展开更多
基金financed by FAPESP-Biota Program(Proc.No.2006/60954-4)CNPq(Proc.No.557872/2008-1).
文摘Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expansion in southeastern Brazil whereas the impact of sugarcane expansion over areas of soybean plantation in previous Cerrado biome is still unknown. However, the expansion of sugarcane production in the state of S?o Paulohas been shown to cause an increase in the local abundance of rodents and result in the emergence of infectious diseases such as hantaviruses and leptospirosis in humans. In addition, with an increase in the use of agrochemicals there will be an increase in euthrophication of watercourses and soil pollution. Considering that S?o Paulo has a population of approximately 40 million people, these local impacts are relevant. Environmental law should be improved and enforced in Brazil to ensure that sugarcane production is not only economically profitable but also environmentally responsible.
文摘In this work,we are concerned with numerical approximation of the gyroaverage operators arising in plasma physics to take into account the effects of the finite Larmor radius corrections.Several methods are proposed in the space configuration and compared to the reference spectral method.We then investigate the influence of the different approximations considering the coupling with some guiding-center models available in the literature.
文摘In this report,a charge preserving numerical resolution of the 1D VlasovAmp`ere equation is achieved,with a forward Semi-Lagrangian method introduced in[10].The Vlasov equation belongs to the kinetic way of simulating plasmas evolution,and is coupled with the Poisson’s equation,or equivalently under charge conservation,the Amp`ere’s one,which self-consistently rules the electric field evolution.In order to ensure having proper physical solutions,it is necessary that the scheme preserves charge numerically.B-spline deposition will be used for the interpolation step.The solving of the characteristics will be made with a Runge-Kutta 2 method and with a Cauchy-Kovalevsky procedure.
文摘We study the number of solutions N(B,F) of the diophantine equation n1n2 = n3n4,where 1 ≤ n1≤B, 1≤ n3 ≤B, n2, n4 ∈ F and F C [1, B] is a factor closed set. We study more particularly the case when F = {m = p1^ε1…pk^εk ,εj∈ {0, 1}, 1≤ j ≤ k}, p1,… ,pk being distinct prime numbers.
基金This work was partially supported by the Agence Nationale de la Recherche,ANR-06-CIS6-0013.
文摘In this paper,we study high order discretization methods for solving the Maxwell equations on hybrid triangle-quad meshes.We have developed high order finite edge element methods coupled with different high order time schemes and we compare results and efficiency for several schemes.We introduce in particular a class of simple high order low dissipation time schemes based on a modified Taylor expansion.
文摘Objective:Nutraceutical products are widely used for their claimed therapeutic benefits.However,falsified or adulterated nutraceuticals present a major health threat to consumers.This study investigates the pharmaceutical quality,safety and anti-inflammatory effects of six male enhancement nutraceuticals that claim to be 100%natural.Methods:Three batches of six male enhancement products were tested to detect the presence and levels of adulterants via high-performance liquid chromatography(HPLC).The pharmaceutical quality of the selected nutraceuticals was tested with near infrared spectroscopy(NIR)and Se De M.The cytotoxic effects of these products on HepG2 cells were determined through cell proliferation(XTT)and lactate dehydrogenase(LDH)cytotoxicity assays.Lastly,the in vitro inflammatory effects of these products were investigated using murine J774 macrophages through cytokine release analysis.Results:HPLC analysis detected the presence of sildenafil citrate,a vasodilator,and the active ingredient in Viagra and Revatio,in all batches of the products we analyzed.Amount of sildenafil citrate ranged from 0.45 mg to 51.85 mg among different batches.NIR assessment showed inter-and intra-batch heterogeneity in product composition.Results of the XTT and LDH assays showed significant cytotoxic effects of the analyzed products.XTT analysis revealed that the viability of HepG2 treated with tested products varied from 27.57%to 41.43%.Interestingly,the male enhancement products also showed anti-inflammatory effects.Conclusion:Despite their labeling as 100%natural,all products tested in this study contained levels of sildenafil citrate,which was not reported on the packaging.There was a lack of pharmaceutical uniformity among products of the same batch and across different batches.Additionally,the products we tested had cytotoxic effects.These study findings highlight the adulteration,poor quality and hazard of these nutraceuticals.Therefore,strict regulation of these products and standardization of the definition of nutraceuticals are urgently needed.Further,these falsely advertised products should be withdrawn from the market due to potential adverse effects on the health of their consumers.