Tezontle from the Anáhuac Basin became Mexico’s second IUGS Heritage Stone in August 2024.This volcanic scoria of basaltic to basaltic-andesitic composition,once considered a‘providential gift’or a‘divine mat...Tezontle from the Anáhuac Basin became Mexico’s second IUGS Heritage Stone in August 2024.This volcanic scoria of basaltic to basaltic-andesitic composition,once considered a‘providential gift’or a‘divine material’,has been used for over twenty centuries in countless architectural monuments,many of which are included in UNESCO’s World Heritage List.The abundant availability of tezontle in central Mexico,combined with its exceptional physical properties of lightness,hardness,and durability,made it the preferred material for building the massive structures of the monumental Pre-Hispanic City of Teotihuacan(1st-7th centuries).展开更多
In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the r...In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the reconstruction of Pleistocene glaciers in Mexico mention the existence of rock glaciers,to date no work has been done to study their physical properties or determining their state of conservation.Since rock glaciers are the most important visible indicators of mountain permafrost(along with features such as gelifluction lobes and patterned ground)and given that the“Nevado”rock glacier is the main example of its kind in Mexico,this study analyzes its internal temperature and assesses its state of conservation.The investigation was carried out by drilling and thermal monitoring of rock profiles as well as air.The results indicate that at present,the“Nevado”seems to lack permafrost inside.Although there is evidence of surface freezing during the winter months in the upper part of the rock glacier,in the lower portion it is almost unnoticed;and in both parts the internal temperature shows a tendency towards positive values as depth increases,a situation that predominates throughout the year.In addition,according to the records of the climatological station located in the lower part of the rock glacier,although the annual rainfall regime could be favorable for the formation and feeding of interstitial or segregated ice,the air temperature conditions throughout the year prevent permanent freezing.The sum of the above determines that at present the“Nevado”could be considered as an inactive and relict-type rock glacier;the presence of vegetation on the surface of the debris that make it up corroborates its inactivity.展开更多
The objective of this work is to reveal the meanings surrounding the discourses and narratives around drinking water services.A documentary,exploratory,and interpretive work was carried out with participants from two ...The objective of this work is to reveal the meanings surrounding the discourses and narratives around drinking water services.A documentary,exploratory,and interpretive work was carried out with participants from two colonies in central Mexico,examining community participation,public functions,and economic occupations.Central and peripheral indicators were generated,although the design of the study limited the results to the sample,suggesting an expansion of the work to include other categories of analysis such as risk perception.展开更多
BACKGROUND Individuals with liver cirrhosis(LC)are likely to experience multiple infectious processes due to the immune dysfunction caused by the disease.Our hypothesis is that this group of patients is predisposed to...BACKGROUND Individuals with liver cirrhosis(LC)are likely to experience multiple infectious processes due to the immune dysfunction caused by the disease.Our hypothesis is that this group of patients is predisposed to fungal infections.To date,the incidence of spontaneous fungal peritonitis(SFP)has not been determined in Mexico;this endeavor is of great importance because many patients may be suffering from this condition without receiving targeted treatment,which may increase mortality.AIM To report the incidence of SFP in patients presenting with decompensated LC with ascites.METHODS This was a prospective,single-center,descriptive,observational and crosssectional study where patients presenting with decompensated LC with ascites were evaluated from November 2023 to May 2024 in Mexico City.Fungal cultures of ascites were performed and the samples kept in an incubator for 10 days to 14 days,and molecular tests(the API 20 C AUX test)were used for molecular characterization.RESULTS Of the 48 patients included,54.2%were women,77.1%had a comorbidity,47.9%had LC secondary to metabolic dysfunction,43.8%were classified as Child-Pugh C with a model for end-stage liver disease 3.0 median score of 22,and 10.4%were in secondary prophylaxis for spontaneous bacterial peritonitis(SBP).Only four patients had positive cultures where Candida parapsilosis and Candida albicans were isolated,with two of the four patients being positive for Rhodotorula minuta;an SBP incidence of 8.3%was thus calculated.Chronic kidney disease[P=0.012 and relative risk(RR)=15]and secondary prophylaxis for SBP(P=0.049 with RR=8.6)were statistically significant and associated with a high mortality risk(P=0.001 with RR=33).CONCLUSION The presence of infection of fungal origin in ascites in patients presenting with cirrhosis increases short-and medium-term mortality;therefore,it is recommended that fungal culture tests are performed in those patients who visit the emergency room or experience continuous admission with acute decompensation and no bacteria identified in ascites cultures,and even more so in patients with chronic kidney disease and a history of antibiotic use as prophylaxis for SBP.Further studies are needed for the identification of clinical and biochemical data that can help to define SFP so that its presence may be assessed without the need to wait for a positive fungal culture.Thus,treatment may be initiated early in the hope of having a positive impact on the prognosis in this group of patients.展开更多
Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This...Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This research focuses on producing a detailed bioclimatic map of Oaxaca,Mexico,at a spatial resolution of 30 arc-seconds,using the methodology developed by Rivas-Martínez et al.(2011).Oaxaca,characterised by its complex topography and diverse climatic conditions,provides a unique opportunity to study bioclimatic patterns in a tropical region.Using high-resolution climate data from Chelsa database,we identified and mapped different bioclimates,variants,thermotypes and ombrotypes horizons and levels of continentality within the tropical macrobioclimate.Our analysis revealed a rich diversity of bioclimatic zones,reflecting the complex interplay between Oaxaca's physical geography and its bioclimates.The results,presented in high resolution maps,highlight the spatial variability and complexity of Oaxaca's bioclimatic landscape.These findings are crucial for several applications,including biodiversity conservation,agricultural planning and climate change adaptation strategies.By providing an accurate bioclimatic classification,this study makes a significant contribution to bioclimatology and could give valuable insights into climate-vegetation relationships in tropical regions.This detailed bioclimatic map improves our understanding of the current ecological status of Oaxaca and serves as a critical tool for future environmental planning and conservation efforts.Furthermore,it could be the basis for planning in national programs that consider agriculture and forests in Mexico such as Programa Sembrando Vida(PSV).展开更多
BACKGROUND Heart transplantation is the last and best option for end-stage heart failure management.Early mortality rates have significantly decreased,enabling patients to survive longer with fewer complications,a tre...BACKGROUND Heart transplantation is the last and best option for end-stage heart failure management.Early mortality rates have significantly decreased,enabling patients to survive longer with fewer complications,a trend observed even in our setting.The primary shared challenge has centered on achieving surgical success and immediate survival.The question arises about the medium-and long-term survival of patients with heart transplant in Mexico.AIM To present the results of the medium and long-term follow-up of heart transplant patients.METHODS This was a retrospective study of a single medical unit,and we selected patients who received heart transplants from July 21,1988 to September 30,2023.Selection criteria encompassed age,sex,and primary indication for heart transplantation across all groups.Patients with incomplete information or who died within 30 postoperative days were excluded.Data of primary pathology,ischemic,extracorporeal circulation,aortic cross-clamping times,length of ventilatory support,stay in postoperative therapy,hospitalization,and functional class were analyzed.RESULTS The causes of morbidity,mortality,and percentage of survival at 1,5,and 10 years were examined.Overall,257 heart transplants were performed during the study period.Of the total cases,22 with incomplete data and 47 who died within 30 postoperative days were excluded for the middle-and long-term survival analyses.Of the remaining 188 patients,heart transplantation was performed(males:146,females:42).The average age of the participants was 44.43±14.48 years.The primary indications included ischemic cardiomyopathy(42.55%)and dilated cardiomyopathy(39.36%).The mean durations of mechanical ventilator support,intensive care stay,and hospital stay were 57.55±103.50 hours,9.96±8.59 days,and 19.49±18.23 days,respectively.One-,five-,and ten-year survival rates were 90.7%,71.3%,and 60.3%,respectively.Of the patients,94%and 6%were in functional classes I and II,respectively.Infection and neurological hemorrhagic or ischemic stroke(26%)were the main causes of mortality in the first year.Subsequently,chronic rejection manifesting as graft vasculopathy increased in frequency(30%).CONCLUSION In our setting,heart transplantation yields medium-and long-term survival and quality of life outcomes comparable to those achieved by other international centers.展开更多
The environmental impact of combustion gas emissions during the cremation process in the municipality of Tlalmanalco,State of Mexico,was investigated.A TESTO 340 combustion analyzer was used over nine days to evaluate...The environmental impact of combustion gas emissions during the cremation process in the municipality of Tlalmanalco,State of Mexico,was investigated.A TESTO 340 combustion analyzer was used over nine days to evaluate 30 cremation services.The average emission values obtained were 84.03 g/h for NO_(2),7,050.9 g/h for SO_(2),and 46,194.4 g/h for CO.Using this data,the dispersion of these pollutants was analyzed with HYSPLIT software and compared with air quality standards.Results showed that the gases dispersed effectively in the air within 1 h,ensuring no risk to the population.However,CO emissions exceeded the limit set by the NADF-017-AIRE-2017 standard for fixed sources,while NO_(2)emissions remained below the permissible limit.展开更多
Jarilla caudata Standl.(Caricaceae)is a wild herbaceous plant native to Mexico recognized for its edible fruits.It is considered to be the closest taxonomically species to Carica papaya L.(Caricaceae),whose seeds have...Jarilla caudata Standl.(Caricaceae)is a wild herbaceous plant native to Mexico recognized for its edible fruits.It is considered to be the closest taxonomically species to Carica papaya L.(Caricaceae),whose seeds have good nutritional and functional properties.This study analyzes and compares the seed chemical compositions of J.caudata and C.papaya to study the nutritional and functional potential of J.caudata seeds.The analysis of the proximate composition was based on standard methods.High-performance liquid chromatography was used to determine the free amino acid profile,gas chromatography to quantify the fatty acid content,and inductively coupled plasma–optical emission spectrometry to measure minerals.Both J.caudata and C.papaya seeds have high protein(24.03%to 26.94%)and lipid(21.32%to 25.07%)content.The mineral study indicated high potassium,calcium,iron,and zinc content.Minor functional compounds present,with similar contents in J.caudata and C.papaya seeds,were soluble sugars,phytic acid,polyphenols,and pectin.The main fatty acid in seed oil was oleic acid(C18:1),with 61.4%in J.caudata seeds and 72.6%in C.papaya seeds.Among free amino acids,leucine with 6.9/100 g free amino acids and phenylalanine with 13.6/100 g free amino acids were the most abundant in the seeds of J.caudata and C.papaya,respectively.Polyphenols of J.caudata and C.papaya seeds showed similar antioxidant activity.J.caudata seeds may represent a useful source of nutritional compounds for food and feeding,and functional compounds with antioxidant activity.展开更多
The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capaci...The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capacity of the pelagic and benthic realms of this Large Marine Ecosystem. Many are the ecological services provided by its waters (fisheries, tourism, aquaculture and fossil fuel reserves) to neighboring countries (US, Mexico and Cuba). However, the unprecedented volumes of hydrocarbons, gas and chemical dispersants (Corexit) introduced in the system, represent ecological stressors whose deleterious effects are still the subject of civil claims and scientific controversy. Presumably, the short scale effects were confined to the Gulf’s northeastern shallow waters, and the combined actions of weathering, biodegradation, and oil recovery left the system almost under pre-spill conditions. Unfortunately, surface and subsurface oil plumes were detected in the spill aftermath, and their dispersion trajectories threatened Mexico EEZ. Surface oil slicks were detected in the pristine waters of northern Yucatán, while subsurface oil plumes from the Macondo’s well blowout were dangerously advancing southwest towards key fishing grounds in the northwestern GoM. This disaster prompted the Mexican government to implement an ambitious ocean monitoring program adopting a bottom-up approach focused on building a base line for more than 42 physicochemical and biological variables for water, sediment and biota from the continental shelf-slope region of the NW GoM. Technological constraints have precluded systematic observations in the vast Mexican EEZ that could discriminate natural variability and oil seep emissions from antropic disturbances. Therefore, preliminary risk analyses relied on seasonal and historical records. Two years of field observations revealed subtle environmental changes in the studied area attributed to antropic disturbances. Waters maintained oligotrophic conditions and zooplankton and benthic infaunal biomass were also poor. Biomarkers in sediments and biota did not exceed EPA’s benchmarks, and sediment’s fingerprinting (δ13C) indicated marine carbon sources. Geomarkers revealed an active transport from the Mississippi towards the NW GoM of phyllosilicates bearing a weathered oil coating. Consequently, shelf and slope sediment toxicity begins to show an increasing trend in the region. The complexity of hydrocarbons bioaccumulation and biodegradation processes in deep waters of the GoM seems to indicate that meso-and large-scale observations may prove to be essential in understanding the capacity of the GoM to recover its ecological stability.展开更多
Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate...Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems, management and conservation plans. Forest fragmentation is defined as the breaking up of a forest unit, where the number of patches and the amount of expose edge increase while the amount of core area decreases. Forest fragmentation studies in Mexico have been limited to local or regional levels and have concen- trated only on specific forest types. This paper presents an assessment of the fragmentation of all forest types at the national level, their effective proximity to anthropogenic influences, and the development of an indica- tor of anthropogenic pressure on the forests areas. Broadleaf forests, tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation. Almost half （47%） of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences. The values for the temperate forests are 23% and 29% respectively. Anthro- pogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests （75 in a scale 0-100） than in the tem- perate forests （30）. When considering these results jointly, the tropical forests, and more specifically, the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degra- dation.展开更多
This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002.The study was based on land use and vegetation cover data sets sca...This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002.The study was based on land use and vegetation cover data sets scale 1：250,000.Two broad forest types（Temperate Forests and Tropical Forests） and five more specific forest types（Broadleaf Forests,and Coniferous Forests;Tropical Dry Deciduous Forests,Tropical Sub-evergreen Forests,and Tropical Evergreen Forests） were defined to conduct the analyses.FragStats 3.3 was used to estimate nine metrics of the spatial pattern of the forests for each forest type and date considered.The results indicate that the land cover transitions that have occurred between 1993 and 2002 have resulted in more isolated forest patches with simpler shapes in both the Temperate and Tropical Forests.The remaining Tropical Forest patches have become smaller and more numerous.In contrast,the remaining Temperate Forest patches are fewer and on average larger.Of the more specific forest types defined in this study,the Broadleaf Forests have the highest indicators of fragmentation.However these forests are usually embedded or adjacent to Coniferous Forests.Of more concern for conservation purposes are the high values of fragmentation metrics found for the Tropical Evergreen Forests and Tropical Dry Deciduous Forests,because these forest types are usually surrounded by non-forest land covers or anthropogenic land uses.展开更多
Landslides induced by prolonged rainfalls are frequent mass movements along the northeastern portion of the Sierra Madre Oriental in Mexico,causing significant damage to infrastructure.In this work,we have studied the...Landslides induced by prolonged rainfalls are frequent mass movements along the northeastern portion of the Sierra Madre Oriental in Mexico,causing significant damage to infrastructure.In this work,we have studied the connection between rainfall and landslides in the Santa Rosa Canyon,a catchment located in the northeastern Mexico.A landslide database triggered by major storms and hurricanes that have hit the region over the past 30 years was analyzed.A total of 92 rainfall events in the Santa Rosa Canyon were studied to determine the amount of precipitation needed to trigger shallow landslides.For each event the duration(D,in hours)and the cumulated rainfall event(E,in mm)were determined by using historical rainfall data from weather stations located near the study area.We have proposed an ED threshold for rainfall-induced landslides with durations 0.5<D<120 hours to address the conditions that trigger these events in the study area.On analyzing the obtained threshold,it has been established that almost 60 mm of a daily rainfall accumulation is required to trigger shallow landslides in the study area.This estimation is consistent with other calculations made for areas close to the Santa Rosa Canyon.Finally,we validated the predictive capability of the threshold with a different set of rainfall data that did not result in landslides performing a straightforward receiver operating characteristic analysis.A good approach was obtained,especially for rainfall events with daily measurements.Results could be used as input information in the design of a landslide early warning system for the northeastern Mexico,and replicated for other landslide prone areas in the region.展开更多
In this study we document the prevalence of gastrointestinal parasites （helminths and protozoans） found in fecal samples of populations of Alouatta palliata mexicana and ofA. pigra in Los Tuxtlas and in Palenque, so...In this study we document the prevalence of gastrointestinal parasites （helminths and protozoans） found in fecal samples of populations of Alouatta palliata mexicana and ofA. pigra in Los Tuxtlas and in Palenque, southeast Mexico, and its re- lation to habitat condition, sex/age and season. Nineteen parasite morphotypes were detected in the fecal samples from populations of the two howler monkeys, of which 58% were shared by both species. When considering all parasite species, populations of the two howler species were more likely to be parasitized in fragmented habitat compared to continuous habitat. Individuals of both howler monkey species that lived in fragmented habitat had a higher prevalence of Controrchis biliophilus. A. p. mexicana individuals had a higher prevalence of Trypanoxyuris minutus than A. pigra, probably the result of the larger group sizes found in the former species, and T. minutus was more likely to be found in A. palliata individuals that lived in fragmented habitat. Adult A. p. mexicana males had a higher risk of being parasitized compared to adult females, but these differences were not detected in A. pigra, Parasite species such as Entamoeba sp., Nematoda sp. 28, Nematoda sp. B and Parabronema sp. where only found during the wet season in both howler monkey species. Populations of both howler monkey species had a higher prevalence of Nematoda sp. A in the wet season and Ascaridae eggs were only detected during the wet season in A. pigra. Other parasites detected displayed no clear seasonal pattern [Current Zoology 58 （3）： 375-383, 2012].展开更多
A sedimentological, petrographic, and geochemical study of beach, dune, and river sands was carried out along the northwestern Gulf of Mexico. The main goal of this work is to show how beach and dune sands are control...A sedimentological, petrographic, and geochemical study of beach, dune, and river sands was carried out along the northwestern Gulf of Mexico. The main goal of this work is to show how beach and dune sands are controlled texturally, compositionally, and chemically by the nearby rivers for each beach location using a particle size analyser, a polarized microscope, a X-ray fluorescence and ICP mass spectrometer to obtain the following: grain-size values from one river (Carrizal River) are similar in range to their counterpart beach sands but not similar to the dune sands (Barra del Tordo). Rivers (Panuco and Carrizal) are compositionally controlling the quartz and feldspar contents of their counterpart beach and dune sands (i.e., Playa Miramar and Barra del Tordo). Rivers (Soto La Marina River) are directly influencing the composition of the beach sands (La Pesca) based upon the total quartz content, beach and dune sands. The concentration of magnetite grain fractions (Barra del Tordo beach and dune sands) is not under the influence of the nearby river (Carrizal River). In this case the compositional influence of beach and dune sands is related to sediment discharges by other fluvial systems, redistribution of the beach and dune sands along the coast and deflation/winnowing of light minerals. The Eu positive anomaly in the beach and dune sands from the three sites (i.e. Playa Miramar, Barra del Tordo, La Pesca) is linked to an increase in the P(plagioclase)/K(potash feldspar) ratio. The (La/Lu)cn highest ratio for river sands (Carrizal River) suggests quartz enrichment compared to their beach and dune sands counterparts. The (Gd/Yb)cn ratio for one river (i.e., Carrizal River) indicates that it is low in heavy rare earth elements. HREE compared to their beach and dune sands counterparts indicates less concentration of heavy minerals as potential carriers of HREE seawards.展开更多
Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adu...Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adults without UL, were included under a case-control association study. Citrate levels in 24-h urine were quantified (citraturia). The polymorphism I550V-hNaDC-1 was determined by PCR-RFLP. Statistical analysis was performed using the STATA10.2 software. Comparison of genotype and allele frequencies between subjects with and without UL showed significant differences for genotype bb (OR = 2.34, CI: 1.19-4.59, p = 0.01) and for allele b (OR = 1.62, CI: 1.15-2.28, p = 0.005), suggesting an association with the risk for UL. Comparison of genotype and allele frequencies between subjects with hypocitraturia and subjects with normocitraturia, did not show any significant difference (p > 0.05), suggesting that this polymorphism is not associated with the risk of hypocitraturia. Interestingly, the risk for UL was increased due to an additive effect of hypocitraturia with the genotype bb (OR = 6.6, CI: 2.38-18.28, p = 0.0002) or with the allele b (OR: 4.2, CI = 2.52-6.97,展开更多
AIM To compare the prevalence of chronic liver disease(CLD) risk factors in a representative sample of MexicanAmericans born in the United States(US) or Mexico, to a sample of adults in Mexico.METHODS Data for Mexican...AIM To compare the prevalence of chronic liver disease(CLD) risk factors in a representative sample of MexicanAmericans born in the United States(US) or Mexico, to a sample of adults in Mexico.METHODS Data for Mexican-Americans in the US were obtained from the 1999-2014 National Health and Nutrition Examination Survey(NHANES), which includes persons of Mexican origin living in the US(n = 4274). The NHANES sample was restricted to Mexican-American participants who were 20 years and older, born in the US or Mexico, not pregnant or breastfeeding, and with medical insurance.The data in Mexico were obtained from the 2004-2013 Health Worker Cohort Study in Cuernavaca, Mexico(n =9485). The following known risk factors for liver disease/cancer were evaluated: elevated aminotransferase levels(elevated alanine aminotransferase was defined as > 40 IU/L for males and females; elevated aspartate aminotransferase was defined as > 40 IU/L for males and females), infection with hepatitis B or hepatitis C,metabolic syndrome, high total cholesterol, diabetes,obesity, abdominal obesity, and heavy alcohol use. The main independent variables for this study classified individuals by country of residence(i.e., Mexico vs the US) and place of birth(i.e., US-born vs Mexico-born).Regression analyses were used to investigate CLD risk factors.RESULTS After adjusting for socio-demographic characteristics,Mexican-American males were more likely to be obese,diabetic, heavy/binge drinkers or have abdominal obesity than males in Mexico. The adjusted multivariate results for females also indicate that Mexican-American females were significantly more likely to be obese, diabetic, be heavy/binge drinkers or have abdominal obesity than Mexican females. The prevalence ratios and prevalence differences mirror the multivariate analysis findings for the aforementioned risk factors, showing a greater risk among US-born as compared to Mexico-born MexicanAmericans. CONCLUSION In this study, Mexican-Americans in the US had more risk factors for CLD than their counterparts in Mexico.These findings can be used to design and implement more effective health promotion policies and programs to address the specific factors that put Mexicans at higher risk of developing CLD in both countries.展开更多
In this work, an analysis of the generation, composition and management of the urban solid waste in Mexico and its relation to greenhouse gas emissions is described;as well a case study in Morelos, a state in the cent...In this work, an analysis of the generation, composition and management of the urban solid waste in Mexico and its relation to greenhouse gas emissions is described;as well a case study in Morelos, a state in the central region of the country. Data were collected from the scientific literature and existing data bases at state and national levels. In addition, the emissions of greenhouse gas were calculated for a period of 14 years, using the Intergovernmental Panel on Climate Change (IPCC) methodology. The municipal solid waste data collected from 1998 to 2012 reveal an increase in the amount of waste generated in Mexico and in Morelos (38% and 43%, respectively), which have been influenced by the urbanization process and the population increase. According to the official data, the composition of the urban solid waste in Mexico, is mostly organic matter (50%), represented by food and garden residues, as well as paper and cardboard (near to 14%). While in Morelos, the percentages of generation for these materials are 44% and 9%, respectively. The management of the urban waste mainly consists of house collection, principally in metropolitan zones and medium and small cities, representing 78.7% in Mexico and 89.2% in Morelos. The second way to eliminate the solid wastes is open burning (mostly in semi-urban and rural areas), representing 14.5% and 6.7% for Mexico and Morelos, respectively. During this period, the nationwide greenhouse gas emissions derived from solid waste management (SWM) increased by 180%, while in Morelos, an increase of 42.5% was calculated. Thus, the population increment and urbanization process were correlated with the rise in the amount of residues generated in Mexico and Morelos.展开更多
In this work is developed a proposal of environment indicators needed for the Environment Impact Assessment (EIA) process in Mexico’s Federal District (FD);through which are authorized the construction and realizatio...In this work is developed a proposal of environment indicators needed for the Environment Impact Assessment (EIA) process in Mexico’s Federal District (FD);through which are authorized the construction and realization of different work actions and activities. The methodology is based on the combination of cabinet and field work, performed in three stages. In the first, a documental review was carried out within the topic of Environment Impact (EI), the EIA and the study area, with a subsequent analysis of the environment indicators at an international, national and regional scale. In the second, the systematization of information was performed for the sixteen study cases at a local scale and the organization and analysis of a data base with the allotted information. And in the last stage, a field work was realized with participative observations in three verification sites and interview applications to the principal actors of the EIA process. These results allowed: to determine the main limitations within the EIA process (methodological, technical and operational), to propose an indicators scheme, and to formulate recommendations focused on the improvement of this Environment Public Policy instrument.展开更多
The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Dom...The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830. The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.展开更多
The objective of the present study was to evaluate the physicochemical properties, presence of water and aflatoxin M1, as well as the effect of the time of year (dry or rainy season) to value the quality and safety of...The objective of the present study was to evaluate the physicochemical properties, presence of water and aflatoxin M1, as well as the effect of the time of year (dry or rainy season) to value the quality and safety of conventional and organic raw milk samples. Samples were collected of conventional (n = 12) and organic (n = 11) raw milk from Tizayuca, Hidalgo and from Tuxpan, Veracruz, respectively. Infrared spectrophotometry and other analytical techniques were employed, approved by the International Dairy Federation for the analysis of the physicochemical properties, the cryoscopy technique for the detection of water addition, and high performance liquid chromatography for the determination of aflatoxin M1. Results showed that there are no significant differences in the components of conventional milk in the season of the year, whereas in organic milk a significant difference (P 0.05) was observed in acidity during the seasons of the year (rainy and dry), as well as a decrease in the percentage of lactose in the dry season, with a significant difference (P 0.05). The means of the cryoscopic point of the milk samples complied with the limits established in the Mexican Official Norm (–0.530, –0.560°H) for milk and no effect was found of the time of year on this variable. Of the milk samples, 50% of the conventional milk and 54.55% of organic milk were above the maximum limits permitted for aflatoxin M1, established in Mexico (0.5 μg·Kg-1).展开更多
文摘Tezontle from the Anáhuac Basin became Mexico’s second IUGS Heritage Stone in August 2024.This volcanic scoria of basaltic to basaltic-andesitic composition,once considered a‘providential gift’or a‘divine material’,has been used for over twenty centuries in countless architectural monuments,many of which are included in UNESCO’s World Heritage List.The abundant availability of tezontle in central Mexico,combined with its exceptional physical properties of lightness,hardness,and durability,made it the preferred material for building the massive structures of the monumental Pre-Hispanic City of Teotihuacan(1st-7th centuries).
文摘In contrast to glaciological studies in Mexico,periglacial studies are very recent and limited to the analysis of the general permafrost cover in the high mountains of the country.Although some of the studies on the reconstruction of Pleistocene glaciers in Mexico mention the existence of rock glaciers,to date no work has been done to study their physical properties or determining their state of conservation.Since rock glaciers are the most important visible indicators of mountain permafrost(along with features such as gelifluction lobes and patterned ground)and given that the“Nevado”rock glacier is the main example of its kind in Mexico,this study analyzes its internal temperature and assesses its state of conservation.The investigation was carried out by drilling and thermal monitoring of rock profiles as well as air.The results indicate that at present,the“Nevado”seems to lack permafrost inside.Although there is evidence of surface freezing during the winter months in the upper part of the rock glacier,in the lower portion it is almost unnoticed;and in both parts the internal temperature shows a tendency towards positive values as depth increases,a situation that predominates throughout the year.In addition,according to the records of the climatological station located in the lower part of the rock glacier,although the annual rainfall regime could be favorable for the formation and feeding of interstitial or segregated ice,the air temperature conditions throughout the year prevent permanent freezing.The sum of the above determines that at present the“Nevado”could be considered as an inactive and relict-type rock glacier;the presence of vegetation on the surface of the debris that make it up corroborates its inactivity.
文摘The objective of this work is to reveal the meanings surrounding the discourses and narratives around drinking water services.A documentary,exploratory,and interpretive work was carried out with participants from two colonies in central Mexico,examining community participation,public functions,and economic occupations.Central and peripheral indicators were generated,although the design of the study limited the results to the sample,suggesting an expansion of the work to include other categories of analysis such as risk perception.
文摘BACKGROUND Individuals with liver cirrhosis(LC)are likely to experience multiple infectious processes due to the immune dysfunction caused by the disease.Our hypothesis is that this group of patients is predisposed to fungal infections.To date,the incidence of spontaneous fungal peritonitis(SFP)has not been determined in Mexico;this endeavor is of great importance because many patients may be suffering from this condition without receiving targeted treatment,which may increase mortality.AIM To report the incidence of SFP in patients presenting with decompensated LC with ascites.METHODS This was a prospective,single-center,descriptive,observational and crosssectional study where patients presenting with decompensated LC with ascites were evaluated from November 2023 to May 2024 in Mexico City.Fungal cultures of ascites were performed and the samples kept in an incubator for 10 days to 14 days,and molecular tests(the API 20 C AUX test)were used for molecular characterization.RESULTS Of the 48 patients included,54.2%were women,77.1%had a comorbidity,47.9%had LC secondary to metabolic dysfunction,43.8%were classified as Child-Pugh C with a model for end-stage liver disease 3.0 median score of 22,and 10.4%were in secondary prophylaxis for spontaneous bacterial peritonitis(SBP).Only four patients had positive cultures where Candida parapsilosis and Candida albicans were isolated,with two of the four patients being positive for Rhodotorula minuta;an SBP incidence of 8.3%was thus calculated.Chronic kidney disease[P=0.012 and relative risk(RR)=15]and secondary prophylaxis for SBP(P=0.049 with RR=8.6)were statistically significant and associated with a high mortality risk(P=0.001 with RR=33).CONCLUSION The presence of infection of fungal origin in ascites in patients presenting with cirrhosis increases short-and medium-term mortality;therefore,it is recommended that fungal culture tests are performed in those patients who visit the emergency room or experience continuous admission with acute decompensation and no bacteria identified in ascites cultures,and even more so in patients with chronic kidney disease and a history of antibiotic use as prophylaxis for SBP.Further studies are needed for the identification of clinical and biochemical data that can help to define SFP so that its presence may be assessed without the need to wait for a positive fungal culture.Thus,treatment may be initiated early in the hope of having a positive impact on the prognosis in this group of patients.
基金support is acknowledged from Universidad Nacional Autónoma de México Project:DGAPA-PAPIIT IN105721,Project IN229325 DGAPAUNAM and Posdoc scholarship for Alejandro González-Pérez(UNAM-DGAPA Postdoctoral Program).
文摘Bioclimatic classification(WBCS),which examines the relationship between vegetation distribution and climatic variables such as precipitation and temperature,is essential for understanding the ecological dynamics.This research focuses on producing a detailed bioclimatic map of Oaxaca,Mexico,at a spatial resolution of 30 arc-seconds,using the methodology developed by Rivas-Martínez et al.(2011).Oaxaca,characterised by its complex topography and diverse climatic conditions,provides a unique opportunity to study bioclimatic patterns in a tropical region.Using high-resolution climate data from Chelsa database,we identified and mapped different bioclimates,variants,thermotypes and ombrotypes horizons and levels of continentality within the tropical macrobioclimate.Our analysis revealed a rich diversity of bioclimatic zones,reflecting the complex interplay between Oaxaca's physical geography and its bioclimates.The results,presented in high resolution maps,highlight the spatial variability and complexity of Oaxaca's bioclimatic landscape.These findings are crucial for several applications,including biodiversity conservation,agricultural planning and climate change adaptation strategies.By providing an accurate bioclimatic classification,this study makes a significant contribution to bioclimatology and could give valuable insights into climate-vegetation relationships in tropical regions.This detailed bioclimatic map improves our understanding of the current ecological status of Oaxaca and serves as a critical tool for future environmental planning and conservation efforts.Furthermore,it could be the basis for planning in national programs that consider agriculture and forests in Mexico such as Programa Sembrando Vida(PSV).
文摘BACKGROUND Heart transplantation is the last and best option for end-stage heart failure management.Early mortality rates have significantly decreased,enabling patients to survive longer with fewer complications,a trend observed even in our setting.The primary shared challenge has centered on achieving surgical success and immediate survival.The question arises about the medium-and long-term survival of patients with heart transplant in Mexico.AIM To present the results of the medium and long-term follow-up of heart transplant patients.METHODS This was a retrospective study of a single medical unit,and we selected patients who received heart transplants from July 21,1988 to September 30,2023.Selection criteria encompassed age,sex,and primary indication for heart transplantation across all groups.Patients with incomplete information or who died within 30 postoperative days were excluded.Data of primary pathology,ischemic,extracorporeal circulation,aortic cross-clamping times,length of ventilatory support,stay in postoperative therapy,hospitalization,and functional class were analyzed.RESULTS The causes of morbidity,mortality,and percentage of survival at 1,5,and 10 years were examined.Overall,257 heart transplants were performed during the study period.Of the total cases,22 with incomplete data and 47 who died within 30 postoperative days were excluded for the middle-and long-term survival analyses.Of the remaining 188 patients,heart transplantation was performed(males:146,females:42).The average age of the participants was 44.43±14.48 years.The primary indications included ischemic cardiomyopathy(42.55%)and dilated cardiomyopathy(39.36%).The mean durations of mechanical ventilator support,intensive care stay,and hospital stay were 57.55±103.50 hours,9.96±8.59 days,and 19.49±18.23 days,respectively.One-,five-,and ten-year survival rates were 90.7%,71.3%,and 60.3%,respectively.Of the patients,94%and 6%were in functional classes I and II,respectively.Infection and neurological hemorrhagic or ischemic stroke(26%)were the main causes of mortality in the first year.Subsequently,chronic rejection manifesting as graft vasculopathy increased in frequency(30%).CONCLUSION In our setting,heart transplantation yields medium-and long-term survival and quality of life outcomes comparable to those achieved by other international centers.
文摘The environmental impact of combustion gas emissions during the cremation process in the municipality of Tlalmanalco,State of Mexico,was investigated.A TESTO 340 combustion analyzer was used over nine days to evaluate 30 cremation services.The average emission values obtained were 84.03 g/h for NO_(2),7,050.9 g/h for SO_(2),and 46,194.4 g/h for CO.Using this data,the dispersion of these pollutants was analyzed with HYSPLIT software and compared with air quality standards.Results showed that the gases dispersed effectively in the air within 1 h,ensuring no risk to the population.However,CO emissions exceeded the limit set by the NADF-017-AIRE-2017 standard for fixed sources,while NO_(2)emissions remained below the permissible limit.
基金financed with an I-COOP project(ref.COOPA 20469)funded by C.S.I.C.To National Council Humanities for Science and Technology(CONAHCYT,Mexico)by the postgraduate scholarship granted to Mario Felipe Gonzalez Gonzalez(No.001073088)。
文摘Jarilla caudata Standl.(Caricaceae)is a wild herbaceous plant native to Mexico recognized for its edible fruits.It is considered to be the closest taxonomically species to Carica papaya L.(Caricaceae),whose seeds have good nutritional and functional properties.This study analyzes and compares the seed chemical compositions of J.caudata and C.papaya to study the nutritional and functional potential of J.caudata seeds.The analysis of the proximate composition was based on standard methods.High-performance liquid chromatography was used to determine the free amino acid profile,gas chromatography to quantify the fatty acid content,and inductively coupled plasma–optical emission spectrometry to measure minerals.Both J.caudata and C.papaya seeds have high protein(24.03%to 26.94%)and lipid(21.32%to 25.07%)content.The mineral study indicated high potassium,calcium,iron,and zinc content.Minor functional compounds present,with similar contents in J.caudata and C.papaya seeds,were soluble sugars,phytic acid,polyphenols,and pectin.The main fatty acid in seed oil was oleic acid(C18:1),with 61.4%in J.caudata seeds and 72.6%in C.papaya seeds.Among free amino acids,leucine with 6.9/100 g free amino acids and phenylalanine with 13.6/100 g free amino acids were the most abundant in the seeds of J.caudata and C.papaya,respectively.Polyphenols of J.caudata and C.papaya seeds showed similar antioxidant activity.J.caudata seeds may represent a useful source of nutritional compounds for food and feeding,and functional compounds with antioxidant activity.
文摘The largest accidental marine oil spill (4.9 million barrels) in the Gulf of Mexico (GoM) seabed (1600 m) caused by the sinking of the Deepwater Horizon oil rig in 2010, put to the test once again the resilient capacity of the pelagic and benthic realms of this Large Marine Ecosystem. Many are the ecological services provided by its waters (fisheries, tourism, aquaculture and fossil fuel reserves) to neighboring countries (US, Mexico and Cuba). However, the unprecedented volumes of hydrocarbons, gas and chemical dispersants (Corexit) introduced in the system, represent ecological stressors whose deleterious effects are still the subject of civil claims and scientific controversy. Presumably, the short scale effects were confined to the Gulf’s northeastern shallow waters, and the combined actions of weathering, biodegradation, and oil recovery left the system almost under pre-spill conditions. Unfortunately, surface and subsurface oil plumes were detected in the spill aftermath, and their dispersion trajectories threatened Mexico EEZ. Surface oil slicks were detected in the pristine waters of northern Yucatán, while subsurface oil plumes from the Macondo’s well blowout were dangerously advancing southwest towards key fishing grounds in the northwestern GoM. This disaster prompted the Mexican government to implement an ambitious ocean monitoring program adopting a bottom-up approach focused on building a base line for more than 42 physicochemical and biological variables for water, sediment and biota from the continental shelf-slope region of the NW GoM. Technological constraints have precluded systematic observations in the vast Mexican EEZ that could discriminate natural variability and oil seep emissions from antropic disturbances. Therefore, preliminary risk analyses relied on seasonal and historical records. Two years of field observations revealed subtle environmental changes in the studied area attributed to antropic disturbances. Waters maintained oligotrophic conditions and zooplankton and benthic infaunal biomass were also poor. Biomarkers in sediments and biota did not exceed EPA’s benchmarks, and sediment’s fingerprinting (δ13C) indicated marine carbon sources. Geomarkers revealed an active transport from the Mississippi towards the NW GoM of phyllosilicates bearing a weathered oil coating. Consequently, shelf and slope sediment toxicity begins to show an increasing trend in the region. The complexity of hydrocarbons bioaccumulation and biodegradation processes in deep waters of the GoM seems to indicate that meso-and large-scale observations may prove to be essential in understanding the capacity of the GoM to recover its ecological stability.
文摘Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation, human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems, management and conservation plans. Forest fragmentation is defined as the breaking up of a forest unit, where the number of patches and the amount of expose edge increase while the amount of core area decreases. Forest fragmentation studies in Mexico have been limited to local or regional levels and have concen- trated only on specific forest types. This paper presents an assessment of the fragmentation of all forest types at the national level, their effective proximity to anthropogenic influences, and the development of an indica- tor of anthropogenic pressure on the forests areas. Broadleaf forests, tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation. Almost half （47%） of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences. The values for the temperate forests are 23% and 29% respectively. Anthro- pogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests （75 in a scale 0-100） than in the tem- perate forests （30）. When considering these results jointly, the tropical forests, and more specifically, the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degra- dation.
文摘This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002.The study was based on land use and vegetation cover data sets scale 1：250,000.Two broad forest types（Temperate Forests and Tropical Forests） and five more specific forest types（Broadleaf Forests,and Coniferous Forests;Tropical Dry Deciduous Forests,Tropical Sub-evergreen Forests,and Tropical Evergreen Forests） were defined to conduct the analyses.FragStats 3.3 was used to estimate nine metrics of the spatial pattern of the forests for each forest type and date considered.The results indicate that the land cover transitions that have occurred between 1993 and 2002 have resulted in more isolated forest patches with simpler shapes in both the Temperate and Tropical Forests.The remaining Tropical Forest patches have become smaller and more numerous.In contrast,the remaining Temperate Forest patches are fewer and on average larger.Of the more specific forest types defined in this study,the Broadleaf Forests have the highest indicators of fragmentation.However these forests are usually embedded or adjacent to Coniferous Forests.Of more concern for conservation purposes are the high values of fragmentation metrics found for the Tropical Evergreen Forests and Tropical Dry Deciduous Forests,because these forest types are usually surrounded by non-forest land covers or anthropogenic land uses.
文摘Landslides induced by prolonged rainfalls are frequent mass movements along the northeastern portion of the Sierra Madre Oriental in Mexico,causing significant damage to infrastructure.In this work,we have studied the connection between rainfall and landslides in the Santa Rosa Canyon,a catchment located in the northeastern Mexico.A landslide database triggered by major storms and hurricanes that have hit the region over the past 30 years was analyzed.A total of 92 rainfall events in the Santa Rosa Canyon were studied to determine the amount of precipitation needed to trigger shallow landslides.For each event the duration(D,in hours)and the cumulated rainfall event(E,in mm)were determined by using historical rainfall data from weather stations located near the study area.We have proposed an ED threshold for rainfall-induced landslides with durations 0.5<D<120 hours to address the conditions that trigger these events in the study area.On analyzing the obtained threshold,it has been established that almost 60 mm of a daily rainfall accumulation is required to trigger shallow landslides in the study area.This estimation is consistent with other calculations made for areas close to the Santa Rosa Canyon.Finally,we validated the predictive capability of the threshold with a different set of rainfall data that did not result in landslides performing a straightforward receiver operating characteristic analysis.A good approach was obtained,especially for rainfall events with daily measurements.Results could be used as input information in the design of a landslide early warning system for the northeastern Mexico,and replicated for other landslide prone areas in the region.
文摘In this study we document the prevalence of gastrointestinal parasites （helminths and protozoans） found in fecal samples of populations of Alouatta palliata mexicana and ofA. pigra in Los Tuxtlas and in Palenque, southeast Mexico, and its re- lation to habitat condition, sex/age and season. Nineteen parasite morphotypes were detected in the fecal samples from populations of the two howler monkeys, of which 58% were shared by both species. When considering all parasite species, populations of the two howler species were more likely to be parasitized in fragmented habitat compared to continuous habitat. Individuals of both howler monkey species that lived in fragmented habitat had a higher prevalence of Controrchis biliophilus. A. p. mexicana individuals had a higher prevalence of Trypanoxyuris minutus than A. pigra, probably the result of the larger group sizes found in the former species, and T. minutus was more likely to be found in A. palliata individuals that lived in fragmented habitat. Adult A. p. mexicana males had a higher risk of being parasitized compared to adult females, but these differences were not detected in A. pigra, Parasite species such as Entamoeba sp., Nematoda sp. 28, Nematoda sp. B and Parabronema sp. where only found during the wet season in both howler monkey species. Populations of both howler monkey species had a higher prevalence of Nematoda sp. A in the wet season and Ascaridae eggs were only detected during the wet season in A. pigra. Other parasites detected displayed no clear seasonal pattern [Current Zoology 58 （3）： 375-383, 2012].
文摘A sedimentological, petrographic, and geochemical study of beach, dune, and river sands was carried out along the northwestern Gulf of Mexico. The main goal of this work is to show how beach and dune sands are controlled texturally, compositionally, and chemically by the nearby rivers for each beach location using a particle size analyser, a polarized microscope, a X-ray fluorescence and ICP mass spectrometer to obtain the following: grain-size values from one river (Carrizal River) are similar in range to their counterpart beach sands but not similar to the dune sands (Barra del Tordo). Rivers (Panuco and Carrizal) are compositionally controlling the quartz and feldspar contents of their counterpart beach and dune sands (i.e., Playa Miramar and Barra del Tordo). Rivers (Soto La Marina River) are directly influencing the composition of the beach sands (La Pesca) based upon the total quartz content, beach and dune sands. The concentration of magnetite grain fractions (Barra del Tordo beach and dune sands) is not under the influence of the nearby river (Carrizal River). In this case the compositional influence of beach and dune sands is related to sediment discharges by other fluvial systems, redistribution of the beach and dune sands along the coast and deflation/winnowing of light minerals. The Eu positive anomaly in the beach and dune sands from the three sites (i.e. Playa Miramar, Barra del Tordo, La Pesca) is linked to an increase in the P(plagioclase)/K(potash feldspar) ratio. The (La/Lu)cn highest ratio for river sands (Carrizal River) suggests quartz enrichment compared to their beach and dune sands counterparts. The (Gd/Yb)cn ratio for one river (i.e., Carrizal River) indicates that it is low in heavy rare earth elements. HREE compared to their beach and dune sands counterparts indicates less concentration of heavy minerals as potential carriers of HREE seawards.
文摘Urolithiasis (UL) is an endemic disease in Southeastern, Mexico. In order to evaluate the association of I550V polymorphism in the hNaDC-1 gene with risk for hypocitraturia and/or for UL;139 adults with UL and 132 adults without UL, were included under a case-control association study. Citrate levels in 24-h urine were quantified (citraturia). The polymorphism I550V-hNaDC-1 was determined by PCR-RFLP. Statistical analysis was performed using the STATA10.2 software. Comparison of genotype and allele frequencies between subjects with and without UL showed significant differences for genotype bb (OR = 2.34, CI: 1.19-4.59, p = 0.01) and for allele b (OR = 1.62, CI: 1.15-2.28, p = 0.005), suggesting an association with the risk for UL. Comparison of genotype and allele frequencies between subjects with hypocitraturia and subjects with normocitraturia, did not show any significant difference (p > 0.05), suggesting that this polymorphism is not associated with the risk of hypocitraturia. Interestingly, the risk for UL was increased due to an additive effect of hypocitraturia with the genotype bb (OR = 6.6, CI: 2.38-18.28, p = 0.0002) or with the allele b (OR: 4.2, CI = 2.52-6.97,
基金Supported by the Programa de Investigación en Migracion y Salud(PIMSA),No.2015-2106the Instituto Mexicano del Seguro Social(IMSS),No.2005/1/Ⅰ/093+2 种基金and the Consejo Nacional de Ciencia y Tecnología(CONACYT),No.26267MNo.SALUD-2011-01-161930the NIH,No.UL1TR000124 to Crespi CM,and NIH/NCI No.K07CA197179 to Flores YN
文摘AIM To compare the prevalence of chronic liver disease(CLD) risk factors in a representative sample of MexicanAmericans born in the United States(US) or Mexico, to a sample of adults in Mexico.METHODS Data for Mexican-Americans in the US were obtained from the 1999-2014 National Health and Nutrition Examination Survey(NHANES), which includes persons of Mexican origin living in the US(n = 4274). The NHANES sample was restricted to Mexican-American participants who were 20 years and older, born in the US or Mexico, not pregnant or breastfeeding, and with medical insurance.The data in Mexico were obtained from the 2004-2013 Health Worker Cohort Study in Cuernavaca, Mexico(n =9485). The following known risk factors for liver disease/cancer were evaluated: elevated aminotransferase levels(elevated alanine aminotransferase was defined as > 40 IU/L for males and females; elevated aspartate aminotransferase was defined as > 40 IU/L for males and females), infection with hepatitis B or hepatitis C,metabolic syndrome, high total cholesterol, diabetes,obesity, abdominal obesity, and heavy alcohol use. The main independent variables for this study classified individuals by country of residence(i.e., Mexico vs the US) and place of birth(i.e., US-born vs Mexico-born).Regression analyses were used to investigate CLD risk factors.RESULTS After adjusting for socio-demographic characteristics,Mexican-American males were more likely to be obese,diabetic, heavy/binge drinkers or have abdominal obesity than males in Mexico. The adjusted multivariate results for females also indicate that Mexican-American females were significantly more likely to be obese, diabetic, be heavy/binge drinkers or have abdominal obesity than Mexican females. The prevalence ratios and prevalence differences mirror the multivariate analysis findings for the aforementioned risk factors, showing a greater risk among US-born as compared to Mexico-born MexicanAmericans. CONCLUSION In this study, Mexican-Americans in the US had more risk factors for CLD than their counterparts in Mexico.These findings can be used to design and implement more effective health promotion policies and programs to address the specific factors that put Mexicans at higher risk of developing CLD in both countries.
文摘In this work, an analysis of the generation, composition and management of the urban solid waste in Mexico and its relation to greenhouse gas emissions is described;as well a case study in Morelos, a state in the central region of the country. Data were collected from the scientific literature and existing data bases at state and national levels. In addition, the emissions of greenhouse gas were calculated for a period of 14 years, using the Intergovernmental Panel on Climate Change (IPCC) methodology. The municipal solid waste data collected from 1998 to 2012 reveal an increase in the amount of waste generated in Mexico and in Morelos (38% and 43%, respectively), which have been influenced by the urbanization process and the population increase. According to the official data, the composition of the urban solid waste in Mexico, is mostly organic matter (50%), represented by food and garden residues, as well as paper and cardboard (near to 14%). While in Morelos, the percentages of generation for these materials are 44% and 9%, respectively. The management of the urban waste mainly consists of house collection, principally in metropolitan zones and medium and small cities, representing 78.7% in Mexico and 89.2% in Morelos. The second way to eliminate the solid wastes is open burning (mostly in semi-urban and rural areas), representing 14.5% and 6.7% for Mexico and Morelos, respectively. During this period, the nationwide greenhouse gas emissions derived from solid waste management (SWM) increased by 180%, while in Morelos, an increase of 42.5% was calculated. Thus, the population increment and urbanization process were correlated with the rise in the amount of residues generated in Mexico and Morelos.
文摘In this work is developed a proposal of environment indicators needed for the Environment Impact Assessment (EIA) process in Mexico’s Federal District (FD);through which are authorized the construction and realization of different work actions and activities. The methodology is based on the combination of cabinet and field work, performed in three stages. In the first, a documental review was carried out within the topic of Environment Impact (EI), the EIA and the study area, with a subsequent analysis of the environment indicators at an international, national and regional scale. In the second, the systematization of information was performed for the sixteen study cases at a local scale and the organization and analysis of a data base with the allotted information. And in the last stage, a field work was realized with participative observations in three verification sites and interview applications to the principal actors of the EIA process. These results allowed: to determine the main limitations within the EIA process (methodological, technical and operational), to propose an indicators scheme, and to formulate recommendations focused on the improvement of this Environment Public Policy instrument.
文摘The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830. The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.
文摘The objective of the present study was to evaluate the physicochemical properties, presence of water and aflatoxin M1, as well as the effect of the time of year (dry or rainy season) to value the quality and safety of conventional and organic raw milk samples. Samples were collected of conventional (n = 12) and organic (n = 11) raw milk from Tizayuca, Hidalgo and from Tuxpan, Veracruz, respectively. Infrared spectrophotometry and other analytical techniques were employed, approved by the International Dairy Federation for the analysis of the physicochemical properties, the cryoscopy technique for the detection of water addition, and high performance liquid chromatography for the determination of aflatoxin M1. Results showed that there are no significant differences in the components of conventional milk in the season of the year, whereas in organic milk a significant difference (P 0.05) was observed in acidity during the seasons of the year (rainy and dry), as well as a decrease in the percentage of lactose in the dry season, with a significant difference (P 0.05). The means of the cryoscopic point of the milk samples complied with the limits established in the Mexican Official Norm (–0.530, –0.560°H) for milk and no effect was found of the time of year on this variable. Of the milk samples, 50% of the conventional milk and 54.55% of organic milk were above the maximum limits permitted for aflatoxin M1, established in Mexico (0.5 μg·Kg-1).
