East Venezuela盆地是一个大型的不对称前陆盆地,具有丰富油气资源。古生代以来,经历了晚三叠世—侏罗纪裂谷、白垩纪—始新世被动边缘和渐新世至今前陆盆地3个演化阶段。纵向上沉积地层可划分为前白垩系、白垩系和后白垩系3套巨层序。E...East Venezuela盆地是一个大型的不对称前陆盆地,具有丰富油气资源。古生代以来,经历了晚三叠世—侏罗纪裂谷、白垩纪—始新世被动边缘和渐新世至今前陆盆地3个演化阶段。纵向上沉积地层可划分为前白垩系、白垩系和后白垩系3套巨层序。East Venezuela盆地最主要的烃源岩是Guayuta群和Tigre组海相泥页岩和碳酸盐岩。生油岩成熟度由北往南递减。北部烃源灶油气经断层、砂体长距离阶梯式向南部斜坡边缘运移。盆地最主要圈闭类型为背斜、断块、地层和岩性圈闭。Oficina组构造、构造—地层、地层圈闭组合和Naricual组构造圈闭组合是盆地内最主要的两套成藏组合。有潜力的勘探领域包括白垩系—下中新统被动边缘沉积层序、盆地中部前渊区、南部重油带和东部海域。展开更多
Jadomycin is an antibiotic that has shown activities against bacteria, yeasts and fungi as well as cytotoxic properties to cancer cells. Because of the wide range of its inhibitory actions, jadomycin shows promise as ...Jadomycin is an antibiotic that has shown activities against bacteria, yeasts and fungi as well as cytotoxic properties to cancer cells. Because of the wide range of its inhibitory actions, jadomycin shows promise as a novel antibiotic and cancer treatment drug. Streptomyces venezuelae are aerobic bacteria that produce jadomycin and the size of bacterial population can significantly affect the yield of jadomycin. Therefore, the bacterial population must be accurately measured in order to standardize the reproducibility of jadomycin production process. In this study, a dehydrogenase activity measurement test, using triphenyl tetrazolium chloride (TTC), was used to measure the dehydrogenase activity of Streptomyces venezuelae during growth in maltose-yeast extract-malt extract (MYM) broth. The aims were to evaluate the effectiveness of the test for measuring microbial growth and to study the effects of the test conditions (incubation time, incubation temperature and medium pH) on triphenyl formazan (TF) yield. The results showed that the TF yield was highly correlated to the optical density. The highest TF yield was observed at a pH of 6 at all incubation times and temperature. Lower TF yields were obtained at higher temperature (40 and 50oC) compared to those obtained at lower temperatures (22 and 30oC). The difference between the yields obtained at 22oC and 30oC were not significant. The differences between incubation time were also not significant. The recommended test conditions are an incubation time of 1 hour at a temperature of 30oC and a pH of 6 followed by three extractions using methanol.展开更多
To investigate the efficiency and stability of Venezuela＇s oil-oriented economy, this paper applied entropy to the analysis.Based on this method, Venezuela＇s oil-centered industry, inefficient regulatory system, and...To investigate the efficiency and stability of Venezuela＇s oil-oriented economy, this paper applied entropy to the analysis.Based on this method, Venezuela＇s oil-centered industry, inefficient regulatory system, and insensitive response to external changes are recognized as an increase in the country＇s entropy. According to these facts, a dissipative structure model is constructed to analyze the efficiency and stability of the Venezuela＇s economic system. The results show that financial assistants（fund flow）, policy reform（policy flow）, and advanced technology（technology flow） can perform as negative entropy inflows（NEIFs）. These NEIFs will promote a series of influence and feedback reactions, which will contribute to recovering Venezuela＇s system efficiency and stability.展开更多
During 15 months the white shrimp (Litopenaeus schmitti) fishing zone was characterized ecologically through the obtaining, compilation and analysis of environmental and physicochemical variables, and modeled the dist...During 15 months the white shrimp (Litopenaeus schmitti) fishing zone was characterized ecologically through the obtaining, compilation and analysis of environmental and physicochemical variables, and modeled the distribution of the relative abundance (CPUE) obtained in 21 fishing sites according to the environmental structure defined by the studied variables. A two-way factorial ANOVA with interaction was used to examine the spatial (fishing sites) and temporal (months) dynamics of CPUE, and a principal component analysis (PCA) was used to discern the environmental structure of the study area. To determine if the environmental structure modeled the distribution of white shrimp, the CPUE values were superimposed on maps of the study area showing strata of the most important physicochemical variables identified by PCA. ANOVA confirmed that the CPUE differed significantly among months (F = 15.6;GL = 11;P P = 0.1979);the interaction term was also not significant (F = 0.52;GL = 10;P = 0.8561). The superimposing of the CPUE on temperature and depth strata confirmed that white shrimp showed greater preference for intermediate temperatures and depths. Petróleos de Venezuela, S.A (PDVSA) contemplates the construction of a multiuse pipeline traversing the study area, by which the current environmental structure of the study area is prone to disturbance. Given the precedent effects represented by an aqueduct construction, it seems PDVSA should anticipate measures to minimize its impact on the fisheries of the zone, particularly on the white shrimp fishery.展开更多
This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the ...This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the most recent study(2019-2020)identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting.Site Fidelity(SF)and Residence(RES)indices were calculated and Agglomerative Hierarchical Clustering(AHC)modeling was performed,with three patterns of residence obtained:resident(25%),semi-resident(17.86%)and transient(57.14%).These results were contrasted with remodeled data from a previous study(2006-2007),showing similar patterns:resident(24.44%),semi-resident(28.89%)and transient(46.67%).Importantly,two individuals were found to have been resident over the extended period.A breeding female sighted for the first time in 2004 and again in 2020(16 years)and the other from 2005 to 2020(15 years).This region is an important area for marine mammals,known to support a resident reproductive population over many years,as well seabirds,sea turtles,whale sharks and fishermen.We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.展开更多
China launched a Venezuelan remote sensing satellite,VRSS-2,into a preset orbit from the Jiuquan Satellite Launch Center at 12：13 Beijing time on October 9.The satellite was launched by a LM-2D carrier rocket which w...China launched a Venezuelan remote sensing satellite,VRSS-2,into a preset orbit from the Jiuquan Satellite Launch Center at 12：13 Beijing time on October 9.The satellite was launched by a LM-2D carrier rocket which was developed by the Shanghai Academy of Spaceflight Technology.展开更多
The U.S.bombing of Caracas,Venezuela,and kidnapping of its democratically elected president Nicolas Maduro in the early hours of January 3,of course,violated an international law regime that the U.S.Government has nev...The U.S.bombing of Caracas,Venezuela,and kidnapping of its democratically elected president Nicolas Maduro in the early hours of January 3,of course,violated an international law regime that the U.S.Government has never had much respect for.Nonetheless,the openness of the discourse surrounding the U.S.'imperial bellicosity is novel in the modem era.展开更多
In an interview with China Hoy(a Spanish-language sister publication of Beijing Review)reporter An Xinzhu,Demetrio Toledo,a professor of international relations at Brazil's Federal University of ABC,explored the b...In an interview with China Hoy(a Spanish-language sister publication of Beijing Review)reporter An Xinzhu,Demetrio Toledo,a professor of international relations at Brazil's Federal University of ABC,explored the broader implications of the recent U.S.attack on Venezuela.展开更多
On January 3,the United States launched a military operation against the sovereign nation of Venezuela.“capturing”its president,Nicolas Maduro.This event is far from a mere isolated"law enforcement operation&qu...On January 3,the United States launched a military operation against the sovereign nation of Venezuela.“capturing”its president,Nicolas Maduro.This event is far from a mere isolated"law enforcement operation";it represents a blatant challenge to the international legal system centered around the United Nations Charter and a thorough and dangerous trampling of the fundamental principles of intemmational relations.展开更多
The focus of the Hazus earthquake model has been largely U.S. centric due to a lack of standardized building-infrastructure data formats applicable elsewhere.In a combined effort between FEMA Region VIII and the Unive...The focus of the Hazus earthquake model has been largely U.S. centric due to a lack of standardized building-infrastructure data formats applicable elsewhere.In a combined effort between FEMA Region VIII and the Universidad de Los Andes, Venezuela, the present study uses the Hazus 2.1 software to simulate earthquake loss estimations for Venezuela. Population totals and demographic distributions were developed using Oak Ridge National Labs Landscan 2008 population data and the census 2011 for Venezuela. The accuracy of the model was further enhanced for Me′rida State, located in western Venezuela, by collecting, incorporating, and developing region and specific inventories including soil maps, liquefaction and landslide susceptibility studies, demographic data, and building inventory information. We used USGS Shake Maps scenarios for two potential earthquake events with peak ground accelerations proposed within Performance Based Seismic Engineering of Buildings, VISION 2000 recommendations. The region has not witnessed an earthquake with a magnitude greater than M 7 in the last120 years. Given the historical record of seismicity and the seismotectonics in the region, it becomes increasingly important to understand the potential implications from moderate to large earthquakes in Me′rida State, Venezuela.展开更多
Background Malaria remains a leading public health problem worldwide.Co-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and management.Similarities in malaria cli...Background Malaria remains a leading public health problem worldwide.Co-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and management.Similarities in malaria clinical presentation with other infections and overlapping endemicity result in underdiagnosis of co-infections and increased mortality.Thus,the aim of this study was to determine the seroprevalence of viral and bacterial pathogens among diagnosed malaria patients in malaria-endemic areas in Venezuela.Methods A cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar,Venezuela.Clinical evaluation and laboratory tests for dengue virus(DENV),chikungunya virus(CHIKV),viral hepatitis[hepatitis A virus(HAV),hepatitis B virus(HBV),and hepatitis C virus(HCV)],and leptospirosis(LEP)were performed by enzyme-linked immunosorbent assays.Previous exposure to these pathogens was defined by the presence of specific immunoglobulin(Ig)G,and co-infection or recent exposure(CoRE)was determined by the presence of specific IgM alone or IgM+IgG.Data analysis considered descriptive statistics.Parameter distribution was statistically evaluated using Kolmogorov–Smirnov test and the necessary comparison tests.Odds ratio(OR)for complications was determined according to CoRE presence with a 95%confidence interval(CI).Results A total of 161 malaria patients were studied,66%infected with Plasmodium vivax,27%with P.falciparum,and 7.5%harboured P.vivax/P.falciparum mixed infection.Previous exposure to DENV(60%)and CHIKV(25%)was frequent.CoRE was confirmed in 55 of the 161 malaria patients(34%)and were more frequent in P.falciparum(49%)than in P.vivax(29%)and mixed malaria patients(25%)(OR=2.43,95%CI:1.39–4.25,P=0.018).The most frequent CoRE was DENV(15%),followed by HAV(12%),HBV(6.2%),CHIKV(5.5%),and LEP(3.7%);HCV CoRE was absent.Complicated malaria was significantly more frequent in patients with CoRE(56%)than those without CoRE(36%;OR=2.31,95%CI:1.18–4.92,P=0.013).Conclusions We found high CoRE prevalence in malaria patients as determined by serology in the study region;cases were associated with a worse clinical outcome.Further prospective studies with samples from different infection sites and the use of molecular tools are needed to determine the clinical significance of these findings.展开更多
文摘Jadomycin is an antibiotic that has shown activities against bacteria, yeasts and fungi as well as cytotoxic properties to cancer cells. Because of the wide range of its inhibitory actions, jadomycin shows promise as a novel antibiotic and cancer treatment drug. Streptomyces venezuelae are aerobic bacteria that produce jadomycin and the size of bacterial population can significantly affect the yield of jadomycin. Therefore, the bacterial population must be accurately measured in order to standardize the reproducibility of jadomycin production process. In this study, a dehydrogenase activity measurement test, using triphenyl tetrazolium chloride (TTC), was used to measure the dehydrogenase activity of Streptomyces venezuelae during growth in maltose-yeast extract-malt extract (MYM) broth. The aims were to evaluate the effectiveness of the test for measuring microbial growth and to study the effects of the test conditions (incubation time, incubation temperature and medium pH) on triphenyl formazan (TF) yield. The results showed that the TF yield was highly correlated to the optical density. The highest TF yield was observed at a pH of 6 at all incubation times and temperature. Lower TF yields were obtained at higher temperature (40 and 50oC) compared to those obtained at lower temperatures (22 and 30oC). The difference between the yields obtained at 22oC and 30oC were not significant. The differences between incubation time were also not significant. The recommended test conditions are an incubation time of 1 hour at a temperature of 30oC and a pH of 6 followed by three extractions using methanol.
基金funded by the National Natural Science Foundation of China (Grant Nos. 71273021 and 7167030506)
文摘To investigate the efficiency and stability of Venezuela＇s oil-oriented economy, this paper applied entropy to the analysis.Based on this method, Venezuela＇s oil-centered industry, inefficient regulatory system, and insensitive response to external changes are recognized as an increase in the country＇s entropy. According to these facts, a dissipative structure model is constructed to analyze the efficiency and stability of the Venezuela＇s economic system. The results show that financial assistants（fund flow）, policy reform（policy flow）, and advanced technology（technology flow） can perform as negative entropy inflows（NEIFs）. These NEIFs will promote a series of influence and feedback reactions, which will contribute to recovering Venezuela＇s system efficiency and stability.
文摘During 15 months the white shrimp (Litopenaeus schmitti) fishing zone was characterized ecologically through the obtaining, compilation and analysis of environmental and physicochemical variables, and modeled the distribution of the relative abundance (CPUE) obtained in 21 fishing sites according to the environmental structure defined by the studied variables. A two-way factorial ANOVA with interaction was used to examine the spatial (fishing sites) and temporal (months) dynamics of CPUE, and a principal component analysis (PCA) was used to discern the environmental structure of the study area. To determine if the environmental structure modeled the distribution of white shrimp, the CPUE values were superimposed on maps of the study area showing strata of the most important physicochemical variables identified by PCA. ANOVA confirmed that the CPUE differed significantly among months (F = 15.6;GL = 11;P P = 0.1979);the interaction term was also not significant (F = 0.52;GL = 10;P = 0.8561). The superimposing of the CPUE on temperature and depth strata confirmed that white shrimp showed greater preference for intermediate temperatures and depths. Petróleos de Venezuela, S.A (PDVSA) contemplates the construction of a multiuse pipeline traversing the study area, by which the current environmental structure of the study area is prone to disturbance. Given the precedent effects represented by an aqueduct construction, it seems PDVSA should anticipate measures to minimize its impact on the fisheries of the zone, particularly on the white shrimp fishery.
基金We thank the fisherman José“Cata”,Grisel Velásquez(UNISIG-IVIC),Laboratory of Ecosystems and Global Change,Venezuelan Institute of Scientific Research,PADI Foundation(N°40470)the Cetacean Society International and the Society of Marine Mammalogy for their funding which enabled this study.
文摘This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua,Venezuela,over a multi-year period.Using photo-identification,the most recent study(2019-2020)identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting.Site Fidelity(SF)and Residence(RES)indices were calculated and Agglomerative Hierarchical Clustering(AHC)modeling was performed,with three patterns of residence obtained:resident(25%),semi-resident(17.86%)and transient(57.14%).These results were contrasted with remodeled data from a previous study(2006-2007),showing similar patterns:resident(24.44%),semi-resident(28.89%)and transient(46.67%).Importantly,two individuals were found to have been resident over the extended period.A breeding female sighted for the first time in 2004 and again in 2020(16 years)and the other from 2005 to 2020(15 years).This region is an important area for marine mammals,known to support a resident reproductive population over many years,as well seabirds,sea turtles,whale sharks and fishermen.We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.
文摘China launched a Venezuelan remote sensing satellite,VRSS-2,into a preset orbit from the Jiuquan Satellite Launch Center at 12：13 Beijing time on October 9.The satellite was launched by a LM-2D carrier rocket which was developed by the Shanghai Academy of Spaceflight Technology.
文摘The U.S.bombing of Caracas,Venezuela,and kidnapping of its democratically elected president Nicolas Maduro in the early hours of January 3,of course,violated an international law regime that the U.S.Government has never had much respect for.Nonetheless,the openness of the discourse surrounding the U.S.'imperial bellicosity is novel in the modem era.
文摘In an interview with China Hoy(a Spanish-language sister publication of Beijing Review)reporter An Xinzhu,Demetrio Toledo,a professor of international relations at Brazil's Federal University of ABC,explored the broader implications of the recent U.S.attack on Venezuela.
文摘On January 3,the United States launched a military operation against the sovereign nation of Venezuela.“capturing”its president,Nicolas Maduro.This event is far from a mere isolated"law enforcement operation";it represents a blatant challenge to the international legal system centered around the United Nations Charter and a thorough and dangerous trampling of the fundamental principles of intemmational relations.
文摘The focus of the Hazus earthquake model has been largely U.S. centric due to a lack of standardized building-infrastructure data formats applicable elsewhere.In a combined effort between FEMA Region VIII and the Universidad de Los Andes, Venezuela, the present study uses the Hazus 2.1 software to simulate earthquake loss estimations for Venezuela. Population totals and demographic distributions were developed using Oak Ridge National Labs Landscan 2008 population data and the census 2011 for Venezuela. The accuracy of the model was further enhanced for Me′rida State, located in western Venezuela, by collecting, incorporating, and developing region and specific inventories including soil maps, liquefaction and landslide susceptibility studies, demographic data, and building inventory information. We used USGS Shake Maps scenarios for two potential earthquake events with peak ground accelerations proposed within Performance Based Seismic Engineering of Buildings, VISION 2000 recommendations. The region has not witnessed an earthquake with a magnitude greater than M 7 in the last120 years. Given the historical record of seismicity and the seismotectonics in the region, it becomes increasingly important to understand the potential implications from moderate to large earthquakes in Me′rida State, Venezuela.
文摘Background Malaria remains a leading public health problem worldwide.Co-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and management.Similarities in malaria clinical presentation with other infections and overlapping endemicity result in underdiagnosis of co-infections and increased mortality.Thus,the aim of this study was to determine the seroprevalence of viral and bacterial pathogens among diagnosed malaria patients in malaria-endemic areas in Venezuela.Methods A cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar,Venezuela.Clinical evaluation and laboratory tests for dengue virus(DENV),chikungunya virus(CHIKV),viral hepatitis[hepatitis A virus(HAV),hepatitis B virus(HBV),and hepatitis C virus(HCV)],and leptospirosis(LEP)were performed by enzyme-linked immunosorbent assays.Previous exposure to these pathogens was defined by the presence of specific immunoglobulin(Ig)G,and co-infection or recent exposure(CoRE)was determined by the presence of specific IgM alone or IgM+IgG.Data analysis considered descriptive statistics.Parameter distribution was statistically evaluated using Kolmogorov–Smirnov test and the necessary comparison tests.Odds ratio(OR)for complications was determined according to CoRE presence with a 95%confidence interval(CI).Results A total of 161 malaria patients were studied,66%infected with Plasmodium vivax,27%with P.falciparum,and 7.5%harboured P.vivax/P.falciparum mixed infection.Previous exposure to DENV(60%)and CHIKV(25%)was frequent.CoRE was confirmed in 55 of the 161 malaria patients(34%)and were more frequent in P.falciparum(49%)than in P.vivax(29%)and mixed malaria patients(25%)(OR=2.43,95%CI:1.39–4.25,P=0.018).The most frequent CoRE was DENV(15%),followed by HAV(12%),HBV(6.2%),CHIKV(5.5%),and LEP(3.7%);HCV CoRE was absent.Complicated malaria was significantly more frequent in patients with CoRE(56%)than those without CoRE(36%;OR=2.31,95%CI:1.18–4.92,P=0.013).Conclusions We found high CoRE prevalence in malaria patients as determined by serology in the study region;cases were associated with a worse clinical outcome.Further prospective studies with samples from different infection sites and the use of molecular tools are needed to determine the clinical significance of these findings.
