The exchange of oxygen (O2) and carbon dioxide (CO2) within an incubator has a significant impact on embryonic development (ED) and hatching processes. This study examines the influence of non-ventilation (NV) conditi...The exchange of oxygen (O2) and carbon dioxide (CO2) within an incubator has a significant impact on embryonic development (ED) and hatching processes. This study examines the influence of non-ventilation (NV) conditions during the first ten days of incubation at high altitudes on Leghorn hens hatching eggs. Five hundred four hatching eggs were equally divided into three treatment groups and placed in twelve incubators (R = 4). The first group was subjected to standard ventilated conditions (V) during the setting phase. The ventilation inlet holes of the remaining incubators in the NV treatments were closed with either micropore (M) or polypropylene (P) tape, referred to as NVM and NVP groups, respectively. These two different airtight settings were intended to allow for a gradual rise in CO2 naturally generated by the embryos. Results indicate that carbon dioxide concentration gradually increased during the first half of incubation, reaching 1.42% in the NVM group and 1.20% in the NVP group, while the V condition group remained at 0.15%. From 10 days of incubation onwards, normal V conditions were restored in all incubators. The highest hatchability of fertile eggs (HFE) was shown by the NVP group (55.7%), followed by the V (52.6%) and NVM (38.6%) groups. The NVP group showed a greater yolk-free body mass (YFBM) from 10 days of incubation until the hatch basket transfer. NV conditions during the first 10 days of incubation at high altitude produced higher YFBM with gradually decreasing yolk sac mass. In comparison to the NVM and V conditions, the particular NVP condition showed a beneficial impact on the quality of hatched chicks. Sustaining NVP condition (1.2% of CO2) throughout the first half of incubation at high altitude generated the optimal environment in the incubator ensuring the best hatchability results. This study highlights how important it is for hatchery managers to recognize the influence of low O2 and high levels of CO2 on the development trajectories of Leghorn embryos during early incubation at high altitudes.展开更多
Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting ...Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of interest.In this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate ions.The study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of ettringite.The amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate removal.The XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon dioxide.The final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/L.Finally,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.展开更多
Melatonin is a pleiotropic molecule that,after a short-term sleep deprivation,promotes the proliferation of neural stem cells in the adult hippocampus.However,this effect has not been observed in long-term sleep depri...Melatonin is a pleiotropic molecule that,after a short-term sleep deprivation,promotes the proliferation of neural stem cells in the adult hippocampus.However,this effect has not been observed in long-term sleep deprivation.The precise mechanism exerted by melatonin on the modulation of neural stem cells is not entirely elucidated,but evidence indicates that epigenetic regulators may be involved in this process.In this study,we investigated the effect of melatonin treatment during a 96-hour sleep deprivation and analyzed the expression of epigenetic modulators predicted by computational text mining and keyword clusterization.Our results showed that the administration of melatonin under sleep-deprived conditions increased the MECP2 expression and reduced the SIRT1 expression in the dentate gyrus.We observed that let-7 b,mir-132,and mir-124 were highly expressed in the dentate gyrus after melatonin administration,but they were not modified by sleep deprivation.In addition,we found more Sox2^+/5-bromo-2’-deoxyuridine(BrdU)^+cells in the subgranular zone of the sleep-deprived group treated with melatonin than in the untreated group.These findings may support the notion that melatonin modifies the expression of epigenetic mediators that,in turn,regulate the proliferation of neural progenitor cells in the adult dentate gyrus under long-term sleep-deprived conditions.All procedures performed in this study were approved by the Animal Ethics Committee of the University of Guadalajara,Mexico(approval No.CI-16610)on January 2,2016.展开更多
The aim of this study is to apply the methodology for assessment of environmental impact of the heritage town with health tourism interest that is assessed. Health tourism is based on the appropriate employment of nat...The aim of this study is to apply the methodology for assessment of environmental impact of the heritage town with health tourism interest that is assessed. Health tourism is based on the appropriate employment of natural resources, landscapes and the natural and cultural heritage of a place. In order to carry out the study, a set of both theoretical and empirical methods were used to analyze the case of Ba?os de Agua Santa. The theoretical methods include the analysis and synthesis employed throughout the research process, as well as in the bibliographic study and the evaluation of the information obtained. In addition, the inductive-deductive method was employed to analyze, process, and treat the information and data that were used frequently in this work. As for the empirical methods, the researchers employed participatory techniques with community stakeholders, in order to gather information through interviews. Also, researchers conducted direct observation of community activities. The automated method software is used which requires a baseline study of the environment assessment in Tungurahua, Ecuador, to be prepared. In addition, the analysis of the social perception on tourism of the local people from the course work of students at the UIDE shall be applied. The conclusions of the case studies undertaken allow for strategic proposals and recommendations to be prepared so that they can be incorporated into the management plans for health tourism in the town with natural heritage value.展开更多
The aim of the present study was to evaluate the effect of feeding four levels of tuna oil on performance and fatty acid (FA) profiles of broiler chicken meat. 240 Ross broiler chickens were randomly assigned to 20 pe...The aim of the present study was to evaluate the effect of feeding four levels of tuna oil on performance and fatty acid (FA) profiles of broiler chicken meat. 240 Ross broiler chickens were randomly assigned to 20 pens and divided into four treatments: 0%, 0.75%, 1%, and 1.25% of tuna oil. At 49 days, breast and legs-thighs muscles were processed for FA analysis. Concentrations of FA in legs and thighs meat were significantly higher when compared with breast meat. In both types of meats (breast and legs-thighs), the inclusion of 1.0% or 1.25% of tuna oil in the diet significantly increased (P < 0.05) the concentration of n-3 FA (especially docosahexaenoic and eicosapentaenoic acids). Fat in broiler breast contained a proportion of 29% saturated FA (SFA): 36% monosaturated FA (MFA): 35% polyunsaturated FA (PUFA);while legs and thighs meat had a proportion of 28% SFA: 38% MFA: 33% PUFA. The addition of tuna oil in the broiler diet significantly reduced the deposition of SFA, MFA, and PUFA in breast meat, while in legs and thighs these reductions were less noticeable. The significant reduction in the concentration of n-6 PUFA and the increment of n-3 PUFA were more evident in breast than in legs and thighs, and with the addition of 1% and 1.25% of tuna oil. The results of the present study suggest a difference in FA deposition attributable to supplementation with tuna oil. The addition of tuna oil could be recommendable to increase n-3 PUFA in both broiler chicken breast and legs-thighs meats, providing a healthier and functional chicken meat to consumer.展开更多
Guadalajara city is the capital of the Mexican federal state of Jalisco. It is located close to the Pacific coast and is subjected to a large seismic risk. We present a seismic response study for some sites along the ...Guadalajara city is the capital of the Mexican federal state of Jalisco. It is located close to the Pacific coast and is subjected to a large seismic risk. We present a seismic response study for some sites along the city. We calculated response spectra of shear-waves by using seismic records of actual earthquakes registered on rock and near the source as Green functions and propagated them trough a flat and horizontal layered media using a linear equivalent method to compare them with the response spectra calculated according to the Federal Commission of Electricity (CFE) seismic design buildings Manual (MOC-2008, 2008) which is widely used as reference on construction projects in Mexico. Our results show that MOC-2008 manual underestimates the spectral amplitudes and frequency band for the response spectra.展开更多
The objective of this study was to isolate entomopathogenic fungus from fleas (Ctenocephalides canis Curtis) collected from Cannis familiaris specimens. From 60 collected fleas, two dead insects presented white myceli...The objective of this study was to isolate entomopathogenic fungus from fleas (Ctenocephalides canis Curtis) collected from Cannis familiaris specimens. From 60 collected fleas, two dead insects presented white mycelia growth on the body surface, changing to a creamy color as time passed;the insects presented a mummified aspect, typical characteristic caused by entomopathogenic fungus. This fungus was identified as Beauveria bassiana (Balsamo-Crivelli) Vuillemin by their mycelia characteristics, macro- and micro-morphology. Up to our knowledge, this is the first report of entomopathogenic fungus isolated from adult C. canis fleas.展开更多
Genomic prediction(GP)has become a valuable tool for predicting the performance of selection candidates for the next breeding cycle.A vast majority of statistical linear models on which GP is based rely on the assumpt...Genomic prediction(GP)has become a valuable tool for predicting the performance of selection candidates for the next breeding cycle.A vast majority of statistical linear models on which GP is based rely on the assumption of normality of the residuals and therefore on the response variable itself.In this study,we propose to use Bayesian regularized quantile regression(BRQR)in the context of GP;the model has been successfully used in other research areas.We evaluated the prediction ability of the proposed model and compared it with the Bayesian ridge regression(BRR;equivalent to genomic best linear unbiased predictor,GBLUP).In addition,BLUP can be used with pedigree information obtained from the coefficient of coancestry(ABLUP).We have found that the prediction ability of BRQR is comparable to that of BRR and,in some cases,better;it also has the potential to efficiently deal with outliers.A program written in the R statistical package is available as Supplementary material.展开更多
The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of ...The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.展开更多
Six weeks BALB/c mice were fed with an atherogenic diet for 24 weeks and purified water ad libitum.An experimental group was given betanidin,orally,during the last 40 days of the experiment at a dose of 9.6 mg per mou...Six weeks BALB/c mice were fed with an atherogenic diet for 24 weeks and purified water ad libitum.An experimental group was given betanidin,orally,during the last 40 days of the experiment at a dose of 9.6 mg per mouse per day.Negative controls were fed with standard rodent chow only.Glycemia was measured at the end of the experiment,after overnight fasting.The group treated with betanidin presented a highly significant reduction of 50.94%compared to positive controls.We conclude that betanidin reduces glycemia in BALB/c mice by an unidentified mechanism.展开更多
For the whole world the source of income,employment,and economic growth has been strongly disrupted by tourism.Today,the context of its membership in the Asia Pacific Economic Cooperation(APEC)plays a fundamental role...For the whole world the source of income,employment,and economic growth has been strongly disrupted by tourism.Today,the context of its membership in the Asia Pacific Economic Cooperation(APEC)plays a fundamental role in achieving a great development;this dissertation analyzes tourism in this block as an economic activity that interacts with the environment,causing not only positive effects such as improving competitiveness,increasing population labor system and an economic increase in the countries that touch it;but also negative consequences,such as tourism overcrowding and poor resource management that can destroy the tourist base on which the sector depends.The theoretical basis of the research rests on the analysis of the proposals for sustainable tourism competitiveness with which this economic block counts,in order to analyze the empirical results of the application of environment and sustainable development indicators with respect to tourism,as well as the perception,on that subject,of national and international by actors and organisms within APEC.展开更多
The study evaluated the effect of time and fatty acid (FA) composition in eggs of laying hens supplemented with tuna oil (TO). Two hundred White Leghorn hens 30-week were divided into 5 treatments with 4 replicates of...The study evaluated the effect of time and fatty acid (FA) composition in eggs of laying hens supplemented with tuna oil (TO). Two hundred White Leghorn hens 30-week were divided into 5 treatments with 4 replicates of 10 birds each. Treatments were assigned randomly and consisted of 0%, 0.75%, 1.50%, 2.25% and 3% TO in commercial sorghum-soybean meal diets, in which the soybean oil was partially replaced. The experiment was conducted for 90 days. At days 28, 56 and 84 of the experiment, 10 eggs per replicate were collected for chemical analysis. Feed intake, egg production rate, egg weight, and feed conversion were not influenced by dietary treatment. FA content was significantly altered (P < 0.05) by TO, showing a progressive increase in egg n-3 FA (especially docosahexaenoic [DHA] and eicosapentaenoic [EPA] acids) when TO was added. Levels of EPA and DHA were higher (P < 0.05) in the egg lipids of TO fed hens than those in the control group. This was correlated (P < 0.05) with the concentration of TO in the diet. However, no significant differences were observed either in egg weight or percent of egg lay between groups. There was a high correlation (P < 0.05) between TO inclusion level in the diet and the incorporation of EPA (r = 0.96) or DHA (r = 0.92) into the egg yolk and an overall decrease in n-6 FA. There was a high correlation (P < 0.05) between TO inclusion level and the incorporation of linoleic acid (LA, r = -0.95) or arachidonic acid (AA, r = -0.96) into the egg yolk. The highest incorporation (P < 0.05) of total n-3 FA content in eggs was obtained with 3% TO/kg. This increase was proportional to TO inclusion levels in the diets (r = 0.95). The results indicate that the n-3 FA content in eggs can be increased by dietary supplementation with TO, and that TO can serve as a reasonable alternative feed ingredient in layer diets to produce a healthier choice of egg.展开更多
This research reports on potentiality in the solar chimney as an exhaust ventilation device through a hypothetical statement that convenient weather conditions exist on sub-humid warm climate to enhance the performanc...This research reports on potentiality in the solar chimney as an exhaust ventilation device through a hypothetical statement that convenient weather conditions exist on sub-humid warm climate to enhance the performance ofa SC (solar chimney), in order to increase ventilation to dissipate metabolic heat from inhabitants of airtight buildings. The methodology used in this research integrates the use of simplified mathematical models that predict in a semi-empirical way a potential volume flow through estimation of kinetic power generation, by natural circulation and stack effect in a typical covered-plate air solar collector. The study was carried out during the warm month of April, an important warm season for Colima, where the prevailing wind is about 6.8 m/s, the average temperature of maximums and minimums oscillates between 15.4℃and 34.4 ℃ with average relative humidity of 65% according to national weather service. A scale model of the SC was installed on environmental chambers. The results showed that this device is capable of generating ventilation conditions around light breeze parameters near between 0.6 m/s and 1.5 m/s width, a better performance at day in 45% approximately than the night values, making ventilation rates up 0.24 ACH (air changes per hour) as average air change rate.展开更多
文摘The exchange of oxygen (O2) and carbon dioxide (CO2) within an incubator has a significant impact on embryonic development (ED) and hatching processes. This study examines the influence of non-ventilation (NV) conditions during the first ten days of incubation at high altitudes on Leghorn hens hatching eggs. Five hundred four hatching eggs were equally divided into three treatment groups and placed in twelve incubators (R = 4). The first group was subjected to standard ventilated conditions (V) during the setting phase. The ventilation inlet holes of the remaining incubators in the NV treatments were closed with either micropore (M) or polypropylene (P) tape, referred to as NVM and NVP groups, respectively. These two different airtight settings were intended to allow for a gradual rise in CO2 naturally generated by the embryos. Results indicate that carbon dioxide concentration gradually increased during the first half of incubation, reaching 1.42% in the NVM group and 1.20% in the NVP group, while the V condition group remained at 0.15%. From 10 days of incubation onwards, normal V conditions were restored in all incubators. The highest hatchability of fertile eggs (HFE) was shown by the NVP group (55.7%), followed by the V (52.6%) and NVM (38.6%) groups. The NVP group showed a greater yolk-free body mass (YFBM) from 10 days of incubation until the hatch basket transfer. NV conditions during the first 10 days of incubation at high altitude produced higher YFBM with gradually decreasing yolk sac mass. In comparison to the NVM and V conditions, the particular NVP condition showed a beneficial impact on the quality of hatched chicks. Sustaining NVP condition (1.2% of CO2) throughout the first half of incubation at high altitude generated the optimal environment in the incubator ensuring the best hatchability results. This study highlights how important it is for hatchery managers to recognize the influence of low O2 and high levels of CO2 on the development trajectories of Leghorn embryos during early incubation at high altitudes.
文摘Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of interest.In this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate ions.The study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of ettringite.The amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate removal.The XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon dioxide.The final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/L.Finally,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.
基金supported by grants from Universidad de Guadalajara(PROSNI 2016,2017-8)to REGCpartially by grants from Consejo Nacional de Ciencia y Tecnologia(CONACyT No.PN 2016-01-465 and INFR-280414)+1 种基金PRODEP(213544)to OGPthe CONACyT Fellowship grant(374823)to AHG
文摘Melatonin is a pleiotropic molecule that,after a short-term sleep deprivation,promotes the proliferation of neural stem cells in the adult hippocampus.However,this effect has not been observed in long-term sleep deprivation.The precise mechanism exerted by melatonin on the modulation of neural stem cells is not entirely elucidated,but evidence indicates that epigenetic regulators may be involved in this process.In this study,we investigated the effect of melatonin treatment during a 96-hour sleep deprivation and analyzed the expression of epigenetic modulators predicted by computational text mining and keyword clusterization.Our results showed that the administration of melatonin under sleep-deprived conditions increased the MECP2 expression and reduced the SIRT1 expression in the dentate gyrus.We observed that let-7 b,mir-132,and mir-124 were highly expressed in the dentate gyrus after melatonin administration,but they were not modified by sleep deprivation.In addition,we found more Sox2^+/5-bromo-2’-deoxyuridine(BrdU)^+cells in the subgranular zone of the sleep-deprived group treated with melatonin than in the untreated group.These findings may support the notion that melatonin modifies the expression of epigenetic mediators that,in turn,regulate the proliferation of neural progenitor cells in the adult dentate gyrus under long-term sleep-deprived conditions.All procedures performed in this study were approved by the Animal Ethics Committee of the University of Guadalajara,Mexico(approval No.CI-16610)on January 2,2016.
文摘The aim of this study is to apply the methodology for assessment of environmental impact of the heritage town with health tourism interest that is assessed. Health tourism is based on the appropriate employment of natural resources, landscapes and the natural and cultural heritage of a place. In order to carry out the study, a set of both theoretical and empirical methods were used to analyze the case of Ba?os de Agua Santa. The theoretical methods include the analysis and synthesis employed throughout the research process, as well as in the bibliographic study and the evaluation of the information obtained. In addition, the inductive-deductive method was employed to analyze, process, and treat the information and data that were used frequently in this work. As for the empirical methods, the researchers employed participatory techniques with community stakeholders, in order to gather information through interviews. Also, researchers conducted direct observation of community activities. The automated method software is used which requires a baseline study of the environment assessment in Tungurahua, Ecuador, to be prepared. In addition, the analysis of the social perception on tourism of the local people from the course work of students at the UIDE shall be applied. The conclusions of the case studies undertaken allow for strategic proposals and recommendations to be prepared so that they can be incorporated into the management plans for health tourism in the town with natural heritage value.
文摘The aim of the present study was to evaluate the effect of feeding four levels of tuna oil on performance and fatty acid (FA) profiles of broiler chicken meat. 240 Ross broiler chickens were randomly assigned to 20 pens and divided into four treatments: 0%, 0.75%, 1%, and 1.25% of tuna oil. At 49 days, breast and legs-thighs muscles were processed for FA analysis. Concentrations of FA in legs and thighs meat were significantly higher when compared with breast meat. In both types of meats (breast and legs-thighs), the inclusion of 1.0% or 1.25% of tuna oil in the diet significantly increased (P < 0.05) the concentration of n-3 FA (especially docosahexaenoic and eicosapentaenoic acids). Fat in broiler breast contained a proportion of 29% saturated FA (SFA): 36% monosaturated FA (MFA): 35% polyunsaturated FA (PUFA);while legs and thighs meat had a proportion of 28% SFA: 38% MFA: 33% PUFA. The addition of tuna oil in the broiler diet significantly reduced the deposition of SFA, MFA, and PUFA in breast meat, while in legs and thighs these reductions were less noticeable. The significant reduction in the concentration of n-6 PUFA and the increment of n-3 PUFA were more evident in breast than in legs and thighs, and with the addition of 1% and 1.25% of tuna oil. The results of the present study suggest a difference in FA deposition attributable to supplementation with tuna oil. The addition of tuna oil could be recommendable to increase n-3 PUFA in both broiler chicken breast and legs-thighs meats, providing a healthier and functional chicken meat to consumer.
文摘Guadalajara city is the capital of the Mexican federal state of Jalisco. It is located close to the Pacific coast and is subjected to a large seismic risk. We present a seismic response study for some sites along the city. We calculated response spectra of shear-waves by using seismic records of actual earthquakes registered on rock and near the source as Green functions and propagated them trough a flat and horizontal layered media using a linear equivalent method to compare them with the response spectra calculated according to the Federal Commission of Electricity (CFE) seismic design buildings Manual (MOC-2008, 2008) which is widely used as reference on construction projects in Mexico. Our results show that MOC-2008 manual underestimates the spectral amplitudes and frequency band for the response spectra.
文摘The objective of this study was to isolate entomopathogenic fungus from fleas (Ctenocephalides canis Curtis) collected from Cannis familiaris specimens. From 60 collected fleas, two dead insects presented white mycelia growth on the body surface, changing to a creamy color as time passed;the insects presented a mummified aspect, typical characteristic caused by entomopathogenic fungus. This fungus was identified as Beauveria bassiana (Balsamo-Crivelli) Vuillemin by their mycelia characteristics, macro- and micro-morphology. Up to our knowledge, this is the first report of entomopathogenic fungus isolated from adult C. canis fleas.
基金The maize and wheat data set used in this study comes from the Drought Tolerance Maize for Africa Project and from CIMMYT's Global Wheat Program.We are thankful to everyone who generated the data used in this article.
文摘Genomic prediction(GP)has become a valuable tool for predicting the performance of selection candidates for the next breeding cycle.A vast majority of statistical linear models on which GP is based rely on the assumption of normality of the residuals and therefore on the response variable itself.In this study,we propose to use Bayesian regularized quantile regression(BRQR)in the context of GP;the model has been successfully used in other research areas.We evaluated the prediction ability of the proposed model and compared it with the Bayesian ridge regression(BRR;equivalent to genomic best linear unbiased predictor,GBLUP).In addition,BLUP can be used with pedigree information obtained from the coefficient of coancestry(ABLUP).We have found that the prediction ability of BRQR is comparable to that of BRR and,in some cases,better;it also has the potential to efficiently deal with outliers.A program written in the R statistical package is available as Supplementary material.
文摘The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg·L-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.
文摘Six weeks BALB/c mice were fed with an atherogenic diet for 24 weeks and purified water ad libitum.An experimental group was given betanidin,orally,during the last 40 days of the experiment at a dose of 9.6 mg per mouse per day.Negative controls were fed with standard rodent chow only.Glycemia was measured at the end of the experiment,after overnight fasting.The group treated with betanidin presented a highly significant reduction of 50.94%compared to positive controls.We conclude that betanidin reduces glycemia in BALB/c mice by an unidentified mechanism.
文摘For the whole world the source of income,employment,and economic growth has been strongly disrupted by tourism.Today,the context of its membership in the Asia Pacific Economic Cooperation(APEC)plays a fundamental role in achieving a great development;this dissertation analyzes tourism in this block as an economic activity that interacts with the environment,causing not only positive effects such as improving competitiveness,increasing population labor system and an economic increase in the countries that touch it;but also negative consequences,such as tourism overcrowding and poor resource management that can destroy the tourist base on which the sector depends.The theoretical basis of the research rests on the analysis of the proposals for sustainable tourism competitiveness with which this economic block counts,in order to analyze the empirical results of the application of environment and sustainable development indicators with respect to tourism,as well as the perception,on that subject,of national and international by actors and organisms within APEC.
文摘The study evaluated the effect of time and fatty acid (FA) composition in eggs of laying hens supplemented with tuna oil (TO). Two hundred White Leghorn hens 30-week were divided into 5 treatments with 4 replicates of 10 birds each. Treatments were assigned randomly and consisted of 0%, 0.75%, 1.50%, 2.25% and 3% TO in commercial sorghum-soybean meal diets, in which the soybean oil was partially replaced. The experiment was conducted for 90 days. At days 28, 56 and 84 of the experiment, 10 eggs per replicate were collected for chemical analysis. Feed intake, egg production rate, egg weight, and feed conversion were not influenced by dietary treatment. FA content was significantly altered (P < 0.05) by TO, showing a progressive increase in egg n-3 FA (especially docosahexaenoic [DHA] and eicosapentaenoic [EPA] acids) when TO was added. Levels of EPA and DHA were higher (P < 0.05) in the egg lipids of TO fed hens than those in the control group. This was correlated (P < 0.05) with the concentration of TO in the diet. However, no significant differences were observed either in egg weight or percent of egg lay between groups. There was a high correlation (P < 0.05) between TO inclusion level in the diet and the incorporation of EPA (r = 0.96) or DHA (r = 0.92) into the egg yolk and an overall decrease in n-6 FA. There was a high correlation (P < 0.05) between TO inclusion level and the incorporation of linoleic acid (LA, r = -0.95) or arachidonic acid (AA, r = -0.96) into the egg yolk. The highest incorporation (P < 0.05) of total n-3 FA content in eggs was obtained with 3% TO/kg. This increase was proportional to TO inclusion levels in the diets (r = 0.95). The results indicate that the n-3 FA content in eggs can be increased by dietary supplementation with TO, and that TO can serve as a reasonable alternative feed ingredient in layer diets to produce a healthier choice of egg.
文摘This research reports on potentiality in the solar chimney as an exhaust ventilation device through a hypothetical statement that convenient weather conditions exist on sub-humid warm climate to enhance the performance ofa SC (solar chimney), in order to increase ventilation to dissipate metabolic heat from inhabitants of airtight buildings. The methodology used in this research integrates the use of simplified mathematical models that predict in a semi-empirical way a potential volume flow through estimation of kinetic power generation, by natural circulation and stack effect in a typical covered-plate air solar collector. The study was carried out during the warm month of April, an important warm season for Colima, where the prevailing wind is about 6.8 m/s, the average temperature of maximums and minimums oscillates between 15.4℃and 34.4 ℃ with average relative humidity of 65% according to national weather service. A scale model of the SC was installed on environmental chambers. The results showed that this device is capable of generating ventilation conditions around light breeze parameters near between 0.6 m/s and 1.5 m/s width, a better performance at day in 45% approximately than the night values, making ventilation rates up 0.24 ACH (air changes per hour) as average air change rate.