The development and implementation of sustainable and environmentally friendly agricultural practices are indispensable as alternatives to pesticide use and to keep populations of soil-borne plant pathogens at levels ...The development and implementation of sustainable and environmentally friendly agricultural practices are indispensable as alternatives to pesticide use and to keep populations of soil-borne plant pathogens at levels that do not affect crop productivity.The present research evaluates the incidence of soil-borne phytopathogens on the pineapple variety MD-2,which was subjected to different treatments:Incorporation of Crotalaria juncea into the soil(organic amendment),application of dolomitic lime to soil(inorganic amendment),and the use of plastic mulch covering the soil.During the crop cycle(15 months),the following variables were evaluated:plant height(cm),fruit weight(kg·plant^(−1)),crop yield(ton·ha^(−1)),the bud root disease incidence caused by Phytophthora nicotianae,number of soil phytoparasitic nematodes and colony-forming-units(CFUs)of soil fungi and oomycetes.The results indicate that Crotalaria juncea treatment reduced the pathogen population(nematode and oomycetes)at levels that did not affect crop development,so that yield increased(18–20%).The incorporation of C.juncea into the soil as an organic amendment favors the populations of fungi disease suppressors(Trichoderma-Aspergillus).The phytoparasitic nematodes(Meloidogyne sp.,Pratylenchus sp.,and Mesocriconema sp.)and oomycetes(Phytophthora spp.,and Pythium spp.)showed a reduction of their population levels by effects of organic amendment(C.juncea).The plastic mulch was also effective,probably due to the maintenance of optimal condition to crop growth and weed control.However,the dolomitic lime application had the poorest effect under the conditions of the study area on the variables analyzed.The described observations are characteristics of a system-based approach for the potential management of soil-borne pathogens of pineapple MD-2 in Veracruz,México.展开更多
Breast cancer is the most common type of malignant tumor among women and their second leading cause of cancer-related deaths.The most common method for screening and diagnosis is mammography.Nonetheless,two main probl...Breast cancer is the most common type of malignant tumor among women and their second leading cause of cancer-related deaths.The most common method for screening and diagnosis is mammography.Nonetheless,two main problems have been identified.First,the dose of radiation received during the test prevents the method from the use on women who are 〈 40 years old.Second,there can be mammogram failure owing to the lack of tumor contrast with the fibrous tissue.Therefore,there is a need for screening methods that will help to identify high-risk cases.We developed a biological marker test that can help to identify them.Increased levels of sialic acid （SA） in saliva are known to correlated with breast cancer.In this study,we evaluated the feasibility of Raman spectroscopy as a method for quantification of SA in saliva,using citrate-reduced silver nanoparticles （cit-Ag-NPs） as a surface-enhanced Raman spectroscopy （SERS） substrate.Quantification of SA was accomplished by measuring its intensity in saliva and comparing it with a calibration curve of SA standards.The mean SA concentration in saliva was found to be significantly higher among 100 breast cancer patients （18.3 ＆#177; 9.4 mg＆#183;dL-1;mean ＆#177; SD） than among 106 healthy controls （3.5 ＆#177; 1.0 mg＆#183;dL-1）.The SERS test showed sensitivity of 94% and specificity 98% for detection of patients with breast cancer,assuming that SA concentration 〉 7 mg＆#183;dL-1 is a cutoff for positive test results.Our findings prove the usefulness of this SERS technique as a simple,convenient,and highly sensitive method of quantitative analysis of SA in saliva.The simplicity of this nanotechnological test may help to substantially reduce the mortality among patients with breast cancer by providing women with a simple,noninvasive screening test that can be applied regardless of age or density of breast tissue.展开更多
Mentum deformities in chironomids have been commonly used as indicators of metal contamination in freshwater ecosystems.Incidence of these deformities suggests sublethal effects and can provide early signals of enviro...Mentum deformities in chironomids have been commonly used as indicators of metal contamination in freshwater ecosystems.Incidence of these deformities suggests sublethal effects and can provide early signals of environmental deterioration.While anthropogenic metal pollution is known to lead to an increase in deformities in chironomids,natural background deformity incidence information is key to their effective use as biomonitoring tools.Here we explore the incidence of deformities from 5000 Tanytarsus(Diptera,Chironomidae)menta in relation to water physicochemical,and sediment metal(Al,As,Cu,Fe,Mn,Pb,Zn)concentration data from numerous sites in the naturally metal-rich Sonora River(NW Mexico)obtained over a two-year period.Higher metal concentrations were found in the upper basin.Higher salinity,total suspended solids and conductivity were found in the lower basin.Only As and Cu were occasionally found above published threshold effect levels(TEL).The proportion of deformities(%D)was low(2.1%)and a generalized linear model only explained 25.36%of%D variability among samples;this model included several physicochemical parameters.The only metal significantly related to deformities was Cu.Despite significant spatial and temporal variability in all metal concentrations and other physicochemical parameters in the basin,we were unable to explain a strong relationship between metal concentration and deformity incidence.Our results,based on consistent%D quantification from 5000 samples from a single taxon,suggest that natural variation in metal concentrations,even when statistically significant,is not associated with notable variations in the incidence of deformities.展开更多
This research was designed to analyze the possible associations of Arg389 Gly ADRB1 and Trp64 Arg ADRB3polymorphisms in children with obesity.A cross-sectional study included 1,046 school-age Mexican participants（6-1...This research was designed to analyze the possible associations of Arg389 Gly ADRB1 and Trp64 Arg ADRB3polymorphisms in children with obesity.A cross-sectional study included 1,046 school-age Mexican participants（6-12 years old） from the cities of San Luis Potosi and Leon.Children were classified as non-obese or obese according to their body mass index（BMI） percentile;obese children had a BMI≥95th percentile for sex and age.Biochemical data were collected.Polymorphisms were detected using TaqMan qPCR assay.A logistic regression analysis was used to calculate the risk of obesity based on genotypes.Differences were found between groups where obese children had a significant increase in systolic and diastolic blood pressure,fasting plasma glucose,insulin,HOMAIR,LDL-cholesterol,triglycerides,and lower HDL-cholesterol compared with the normal weight group（P 〈 0.05）.The distribution of allele frequency in the population was Arg = 87.4 and Gly = 12.6（Hardy Weinberg equilibrium x^2= 3.16,P = 0.07）;Trp = 81.5 and Arg= 18.5（Hardy Weinberg equilibrium x^2 = 2.2,P = 0.14） for ADRB1 and ADRB3,respectively.Even though no different frequencies of Arg389 Gly polymoiphism between groups were found（P = 0.08）,children carriers of one Gly389,ADRB1 allele had a risk for obesity of OR = 1.40（95%CI,1.03-1.90,P =0.03） after adjustment for age and gender.No other association was found for Trp64 Arg ADRB3 polymorphism.Only the Arg389 Gly ADRB1 polymorphism was associated with risk for obesity in Mexican children.展开更多
文摘The development and implementation of sustainable and environmentally friendly agricultural practices are indispensable as alternatives to pesticide use and to keep populations of soil-borne plant pathogens at levels that do not affect crop productivity.The present research evaluates the incidence of soil-borne phytopathogens on the pineapple variety MD-2,which was subjected to different treatments:Incorporation of Crotalaria juncea into the soil(organic amendment),application of dolomitic lime to soil(inorganic amendment),and the use of plastic mulch covering the soil.During the crop cycle(15 months),the following variables were evaluated:plant height(cm),fruit weight(kg·plant^(−1)),crop yield(ton·ha^(−1)),the bud root disease incidence caused by Phytophthora nicotianae,number of soil phytoparasitic nematodes and colony-forming-units(CFUs)of soil fungi and oomycetes.The results indicate that Crotalaria juncea treatment reduced the pathogen population(nematode and oomycetes)at levels that did not affect crop development,so that yield increased(18–20%).The incorporation of C.juncea into the soil as an organic amendment favors the populations of fungi disease suppressors(Trichoderma-Aspergillus).The phytoparasitic nematodes(Meloidogyne sp.,Pratylenchus sp.,and Mesocriconema sp.)and oomycetes(Phytophthora spp.,and Pythium spp.)showed a reduction of their population levels by effects of organic amendment(C.juncea).The plastic mulch was also effective,probably due to the maintenance of optimal condition to crop growth and weed control.However,the dolomitic lime application had the poorest effect under the conditions of the study area on the variables analyzed.The described observations are characteristics of a system-based approach for the potential management of soil-borne pathogens of pineapple MD-2 in Veracruz,México.
文摘Breast cancer is the most common type of malignant tumor among women and their second leading cause of cancer-related deaths.The most common method for screening and diagnosis is mammography.Nonetheless,two main problems have been identified.First,the dose of radiation received during the test prevents the method from the use on women who are 〈 40 years old.Second,there can be mammogram failure owing to the lack of tumor contrast with the fibrous tissue.Therefore,there is a need for screening methods that will help to identify high-risk cases.We developed a biological marker test that can help to identify them.Increased levels of sialic acid （SA） in saliva are known to correlated with breast cancer.In this study,we evaluated the feasibility of Raman spectroscopy as a method for quantification of SA in saliva,using citrate-reduced silver nanoparticles （cit-Ag-NPs） as a surface-enhanced Raman spectroscopy （SERS） substrate.Quantification of SA was accomplished by measuring its intensity in saliva and comparing it with a calibration curve of SA standards.The mean SA concentration in saliva was found to be significantly higher among 100 breast cancer patients （18.3 ＆#177; 9.4 mg＆#183;dL-1;mean ＆#177; SD） than among 106 healthy controls （3.5 ＆#177; 1.0 mg＆#183;dL-1）.The SERS test showed sensitivity of 94% and specificity 98% for detection of patients with breast cancer,assuming that SA concentration 〉 7 mg＆#183;dL-1 is a cutoff for positive test results.Our findings prove the usefulness of this SERS technique as a simple,convenient,and highly sensitive method of quantitative analysis of SA in saliva.The simplicity of this nanotechnological test may help to substantially reduce the mortality among patients with breast cancer by providing women with a simple,noninvasive screening test that can be applied regardless of age or density of breast tissue.
基金This project was carried out with support from CONACYT to OCBG(Author)via Graduate(MS)Scholarship No:903227Support was also provided by project 84460256 to the Instituto Mexicano de Tecnología del Agua and project PRODEP project DSA/103.5/15/3073 to NMS(Author).
文摘Mentum deformities in chironomids have been commonly used as indicators of metal contamination in freshwater ecosystems.Incidence of these deformities suggests sublethal effects and can provide early signals of environmental deterioration.While anthropogenic metal pollution is known to lead to an increase in deformities in chironomids,natural background deformity incidence information is key to their effective use as biomonitoring tools.Here we explore the incidence of deformities from 5000 Tanytarsus(Diptera,Chironomidae)menta in relation to water physicochemical,and sediment metal(Al,As,Cu,Fe,Mn,Pb,Zn)concentration data from numerous sites in the naturally metal-rich Sonora River(NW Mexico)obtained over a two-year period.Higher metal concentrations were found in the upper basin.Higher salinity,total suspended solids and conductivity were found in the lower basin.Only As and Cu were occasionally found above published threshold effect levels(TEL).The proportion of deformities(%D)was low(2.1%)and a generalized linear model only explained 25.36%of%D variability among samples;this model included several physicochemical parameters.The only metal significantly related to deformities was Cu.Despite significant spatial and temporal variability in all metal concentrations and other physicochemical parameters in the basin,we were unable to explain a strong relationship between metal concentration and deformity incidence.Our results,based on consistent%D quantification from 5000 samples from a single taxon,suggest that natural variation in metal concentrations,even when statistically significant,is not associated with notable variations in the incidence of deformities.
基金supports by Consejo Nacional de Ciencia y Tecnologia(CONACYT) No.Approval 2002020201
文摘This research was designed to analyze the possible associations of Arg389 Gly ADRB1 and Trp64 Arg ADRB3polymorphisms in children with obesity.A cross-sectional study included 1,046 school-age Mexican participants（6-12 years old） from the cities of San Luis Potosi and Leon.Children were classified as non-obese or obese according to their body mass index（BMI） percentile;obese children had a BMI≥95th percentile for sex and age.Biochemical data were collected.Polymorphisms were detected using TaqMan qPCR assay.A logistic regression analysis was used to calculate the risk of obesity based on genotypes.Differences were found between groups where obese children had a significant increase in systolic and diastolic blood pressure,fasting plasma glucose,insulin,HOMAIR,LDL-cholesterol,triglycerides,and lower HDL-cholesterol compared with the normal weight group（P 〈 0.05）.The distribution of allele frequency in the population was Arg = 87.4 and Gly = 12.6（Hardy Weinberg equilibrium x^2= 3.16,P = 0.07）;Trp = 81.5 and Arg= 18.5（Hardy Weinberg equilibrium x^2 = 2.2,P = 0.14） for ADRB1 and ADRB3,respectively.Even though no different frequencies of Arg389 Gly polymoiphism between groups were found（P = 0.08）,children carriers of one Gly389,ADRB1 allele had a risk for obesity of OR = 1.40（95%CI,1.03-1.90,P =0.03） after adjustment for age and gender.No other association was found for Trp64 Arg ADRB3 polymorphism.Only the Arg389 Gly ADRB1 polymorphism was associated with risk for obesity in Mexican children.
