Dear Editor,Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the Flaviviridae family,which causes dengue—a disease affecting over 400 million people annually worldwide.DENV is transmitted ...Dear Editor,Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the Flaviviridae family,which causes dengue—a disease affecting over 400 million people annually worldwide.DENV is transmitted through the bite of mosquitoes from the Aedes genus,primarily Aedes aegypti,and has a wide distribution in tropical and subtropical areas(de Souza et al.,2022).展开更多
BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in M...BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in Mexico.METHODS LT waitlist registrations and LT rates in Mexico from 2014 to 2023 were assessed.LT listings per million persons(pmp)were calculated.Observed-to-expected listings were calculated by controlling listings pmp and mortality rate per 10000.LT and waitlist mortality was calculated as 90-day rate,overall rate and rate per 100 person-years.We compared access to waitlist,transplantation and mortality between patients living in Mexican States with higher LT activity and those living in other States.RESULTS There were 2600 new waitlist registrations;1572 registrations(60.4%)living in Mexico City and State,Jalisco and Nuevo Leon.There were 1755 LT;92.5%of them performed in States with higher LT activity,and 1101(62.7%vs 37.3%;P<0.001)done in patients living in those States.Listings pmp in the Mexican States with high LT activity were 3.8,1.5 vs 1.2,0.6(P<0.001);observed-to-expected listings were 1.3,0.4 vs 0.4,0.2(P<0.001);LT pmp were 2.7,0.9 vs 0.7,0.5(P<0.001).After controlling for other variables,patients living in high LT activity States had a HR 1.14(95%CI:1.03-1.26;P=0.009)to be a case of transplantation after listing.CONCLUSION Geographic disparities substantially affect LT access in Mexico.The population living near Transplant Centers has a 3.2-fold higher access to the waiting list and a 3.8-fold higher likelihood of LT.Current referral system,and resource allocation need urgent revision to remove the barriers associated with geographic disparity.展开更多
On the morning of October 15,people from different countries will queue up at the entrance of Centro Banamex,the international convention and exhibition center in Mexico.There are local dealers present,Brazilian build...On the morning of October 15,people from different countries will queue up at the entrance of Centro Banamex,the international convention and exhibition center in Mexico.There are local dealers present,Brazilian builders identifiable by their yellow-green,fluorescent vests,Canadian buyers carrying computer bags,and a group of Chinese individuals with aluminum alloy suitcases labeled“Foshan Ceramics”,“Yongkang Hardware”,and“Anji Bamboo Floor”.展开更多
Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of ...Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of the lowest LT rates in Latin America.Multiple challenges remain,including inequitable access to care,limited organ donation,and structural inefficiencies in allocation systems.To review the current status of LT in Mexico,describe historical trends,highlight significant barriers to progress,and discuss potential opportunities for program expansion.We conducted a narrative review incorporating data from the National Transplant Center(Centro Nacional de Trasplantes in Spanish),relevant peer-reviewed literature,and global benchmarks.The analysis focused on trends in liver transplant volume,donor types,etiology shifts,institutional disparities,and the impact of the coronavirus disease 2019(COVID-19)pandemic.LT activity in Mexico increased from 25 transplants in 1999 to 297 in 2023.However,over 68%of transplants are concentrated in Mexico City,and only eight centers perform more than ten LTs per year.Deceased donors account for most grafts,while living donor transplants remain rare and mostly limited to private institutions.The national waiting list functions primarily as a registry rather than a priority-based allocation system.The COVID-19 pandemic further disrupted transplant programs,particularly in the public sector.Innovative approaches such as donation after circulatory death,hepatitis C virus-positive donor utilization,and advanced perfusion technologies are currently unavailable or underutilized in Mexico.Mexico's LT system faces geographic,regulatory,and resource-related limitations.To improve outcomes and ensure equitable access,strategic reforms focused on donor expansion,centralized allocation,perfusion technologies,and standardization of care are urgently needed.展开更多
Genomic medicine has evolved significantly,merging centuries of scientific progress with modern molecular biology and clinical care.It utilizes knowledge of the human genome to enhance disease prevention,diagnosis,tre...Genomic medicine has evolved significantly,merging centuries of scientific progress with modern molecular biology and clinical care.It utilizes knowledge of the human genome to enhance disease prevention,diagnosis,treatment,and potential reversal.Genomic medicine in hepatology is particularly promising due to the crucial role of the liver in several metabolic processes and its association with diseases such as metabolic dysfunction-associated steatotic liver disease,type 2 diabetes mellitus,liver cirrhosis,and cardiovascular conditions.The mid-20th century witnessed a paradigm shift in medicine,marked by the emergence of molecular biology,which enabled a deeper understanding of gene expression and regulation.This connection between basic science and clinical practice has enhanced our knowledge of the role of gene-environment interactions in the onset and progression of liver diseases.In Latin America,including Mexico,with its genetically diverse and admixed populations,genomic medicine provides a foundation for personalized and culturally relevant health strategies.This review highlights the need for genomic medicine,examining its historical evolution,integration into hepatology in Mexico,and its potential applications in the prevention of chronic diseases.It emphasizes the importance of training in genomic literacy and interdisciplinary education in medical training,particularly in the field of hepatology,with a focus on genomic medicine expertise.展开更多
The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic v...The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic vulnerability and resilience in the country.This paper provides a comprehensive review of the damage on the built environment,emergency response,recovery and reconstruction efforts,regulatory evolution,and institu-tional reforms that followed these events.Key topics include the performance of self-built housing and essential infrastructure,the challenges of decentralized building codes and their uneven development and enforcement,the role of civil society,private sector and media in disaster response,and the implementation of the National Reconstruction Program.Advances in seismic code development-particularly the updated Complementary Technical Norms(CTNs)of Mexico City-and the creation of a dedicated standard for the evaluation and rehabilitation of existing buildings are also discussed.The proposed Construction Law for Mexico City,which aims to assign legal responsibility to stakeholders and formalize the regulatory framework,may serve as a legislative model for other regions.The paper concludes by highlighting the importance of coordination,tech-nical rigor,equity and inclusion in recovery and reconstruction,and public engagement in advancing seismic resilience across diverse urban,semi-urban and rural contexts.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
This paper compares monthly and seasonal rain rates derived from the Version 5 （V5） and Version 6 （V6） TRMM Precipitation Radar （TPR, TSDIS reference 2A25）, TRMM Microwave Imager （TMI, 2A12）, TRMM Combined Ins...This paper compares monthly and seasonal rain rates derived from the Version 5 （V5） and Version 6 （V6） TRMM Precipitation Radar （TPR, TSDIS reference 2A25）, TRMM Microwave Imager （TMI, 2A12）, TRMM Combined Instrument （TCI, 2B31）, TRMM calibrated IR rain estimates （3B42） and TRMM merged gauge and satellite analysis （3B43） algorithms over New Mexico （NM） with rain gauge analyses provided by the New Mexico water districts （WD）. The average rain rates over the NM region for 1998- 2002 are 0.91 mm d^-1 for WD and 0.75, 1.38, 1.49, 1.27, and 1.07 mm d^-1 for V5 3B43, 3B42, TMI, PR and TCA; and 0.74, 1.38, 0.87 and 0.97 mm d^-1 for V6 3B43, TMI, TPR and TCA, respectively. Comparison of V5 3B43 with WD rain rates and the daily TRMM mission index （TPR and TMI） suggests that the low bias of V5 3B43 for the wet months （summer to early fall） may be due to the non-inclusion of some rain events in the operational gauge analyses that. are used in the production of V5 3B43. Correlation analyses show that the WD rain rates vary in phase, with higher correlation between neighboring WDs. High temporal correlations （〉0.8） exist between WD and the combined algorithms （3B42, 3B43 and TCA for both V5 and V6） while satellite instrument algorithms （PR, TMI and TCI） are correlated best among themselves at the monthly scale. Paired t-tests of the monthly time series show that V5 3B42 and TMI are statistically different from the WD rain rates while no significant difference exists between WD and the other products. The agreements between the TRMM satellite and WD gauge estimates are best for the spring and fall and worst for winter and summer. The reduction in V6 TMI （-7.4%） and TPR （-31%） rain rates （compared to V5） results in better agreement between WD estimates and TMI in winter and TPR during summer.展开更多
Hepatitis B virus(HBV)genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics,progression,severity of disease and antiviral response.Herein,we provide an u...Hepatitis B virus(HBV)genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics,progression,severity of disease and antiviral response.Herein,we provide an updated overview of the endemicity of HBV genotypes H and G in Mexico.HBV genotype H is predominant among the Mexican population,but not in Central America.Its geographic distribution is related to a typical endemicity among the Mexicans which is characterized by a low hepatitis B surface antigen seroprevalence,apparently due to a rapid resolution of the infection,low viral loads and a high prevalence of occult B infection.During chronic infections,genotype H is detected in mixtures with other HBV genotypes and associated with other co-morbidities,such as obesity,alcoholism and co-infection with hepatitis C virus or human immunodeficiency virus.Hepatocellular carcinoma prevalence is low.Thus,antiviral therapy may differ significantly from the standard guidelines established worldwide.The high prevalence of HBV genotype G in the Americas,especially among the Mexican population,raises new questions regarding its geographic origin that will require further investigation.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
Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide.Identifying the driving factors and understanding the contribution of each fa...Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide.Identifying the driving factors and understanding the contribution of each factor are essential for the management of forest fire occurrence.The objective of this study is to identify variables that are spatially related to the occurrence and incidence of the forest fire in the State of Durango,Mexico.For this purpose,data from forest fire records for a five-year period were analyzed.The spatial correlations between forest fire occurrence and intensity of land use,susceptibility of vegetation,temperature,precipitation and slope were tested by Geographically Weighted Regression(GWR) method,under an Ordinary Least Square estimator.Results show that the spatial pattern of the forest fire in the study area is closely correlated with the intensity of land use,and land use change is one of the main explanatory variables.In addition,vegetation type and precipitation are also the main driving factors.The fitting model indicates obvious link between the variables.Forest fire was found to be the consequence of a particular combination of the environmental factors,and when these factors coexist with human activities,there is high probability of forest fire occurrence.Mandatory regulation of human activities is a key strategy for forest fire prevention.展开更多
Re-vegetation plays a fundamental role for erosion control and plant recovery in lands affected by gully erosion. Bioengineered practices facilitate the gullies rehabilitation. Objectives of the research were: 1) Iden...Re-vegetation plays a fundamental role for erosion control and plant recovery in lands affected by gully erosion. Bioengineered practices facilitate the gullies rehabilitation. Objectives of the research were: 1) Identify taxonomically the pioneer vegetation on each gully section; 2) Characterize vegetation distribution preferences and 3) Assess structural/functional traits to recognize erosion control key species. Bioengineering was applied in a watershed belonging to Sierra Madre del Sur, at Oaxaca, Mexico, on eight gullies, with local support and minimal investment. "La Mixteca" is a poor ecological and socio-economic region, comparable to other regions of the world. The Initial Floristic Composition(IFC) inventory is the baseline of the successional process. The transect method was used to determine the colonization of species. Cover abundance of registered species was estimated using the semi-quantitative scale of Braun-Blanquet. This procedure was repeated in five different positions(floor, hillslopes and tops), in the cross section of the gully. Throughcorrespondence analysis and clustering, the distribution of species was analyzed. Adequate responses were obtained in soil retention(quantity) and plant cover(existence and diversity); as measurable indicators of the bioengeneering works efficiency. Occupation of soil by native species from the Tropical Deciduous Forest was favored using live barriers. We detected species guilds with spatial distribution preferences in the gullies cross section. Plant cover characterization includes: native colonizer species, herbaceous, shrubby and trees of the forest community bordering the gully area, with cover abundance and structural/functional traits, useful to protect degraded areas. This spatial occupation process of plants responds to a secondary succession in gullies, where the proposed IFC model is correctly represented through bioengineering. Natural establishment of plants was successful by traits of species such as extensive root system and sexual/vegetative reproduction.展开更多
In October 1999, rainfall induced landslides devastated different communities of the Sierra Norte, Puebla, causing more than 250 victims and economic losses greater than $ 450 million. The town of Zacapoaxtla was one ...In October 1999, rainfall induced landslides devastated different communities of the Sierra Norte, Puebla, causing more than 250 victims and economic losses greater than $ 450 million. The town of Zacapoaxtla was one of the sectors most affected by slope instability due to the existing geological features and geomorphic characters determined by material properties, landforms and processes. Extensive areas formed by pyroclastic piedmonts developed on the Quaternary volcanic ignimbrite deposits highly dissected by marginal gully erosion combined with an extreme rainfall event played a significant role as an ideal scenario for the occurrence of landsliding. Distribution of landslides triggered by rainfall within the main sector of the Zacapoaxtla municipality was analyzed by using IKONOS images in terms of exploring the likely relationship between mass movement incidence and levels of vegetation density. The later was undertaken by means of producing an NDVI and applying a fragmentation algorithm. Finally, a map of potential areas of mass movements risk was produced based on the combination of a socio-economic vulnerability index, geologic and geomorphological maps and the spatial landslide distribution.展开更多
Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temper...Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo, Mexico some oak trees were heavily infested by honeydew-producing insects （family Margarodidae, tribe Xylococcini, genus Strigmacoccus） and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honey- dew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such re- sources. Four hummingbird species consumed this resource （Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens）. Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the dally times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively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
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
The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission...The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission for the Knowledge and Use of Biodiversity(CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost(erosion) or gained(accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time;coastline change rates having duplicated between the earliest(1970/81–2005) and the two more recent(2005–2010, and 2010–2015) analysed time periods, with erosion rates for each corresponding period of –3 m/yr,–7.5 m/yr, and –7.3 m/yr,and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.展开更多
文摘Dear Editor,Dengue virus(DENV)is a positive-sense single-stranded RNA virus belonging to the Flaviviridae family,which causes dengue—a disease affecting over 400 million people annually worldwide.DENV is transmitted through the bite of mosquitoes from the Aedes genus,primarily Aedes aegypti,and has a wide distribution in tropical and subtropical areas(de Souza et al.,2022).
文摘BACKGROUND Liver disease is a major cause of mortality in Mexico.Liver transplantation(LT)remains severely limited,and there are no reports on equity of access.AIM To analyze geographical disparities in LT access in Mexico.METHODS LT waitlist registrations and LT rates in Mexico from 2014 to 2023 were assessed.LT listings per million persons(pmp)were calculated.Observed-to-expected listings were calculated by controlling listings pmp and mortality rate per 10000.LT and waitlist mortality was calculated as 90-day rate,overall rate and rate per 100 person-years.We compared access to waitlist,transplantation and mortality between patients living in Mexican States with higher LT activity and those living in other States.RESULTS There were 2600 new waitlist registrations;1572 registrations(60.4%)living in Mexico City and State,Jalisco and Nuevo Leon.There were 1755 LT;92.5%of them performed in States with higher LT activity,and 1101(62.7%vs 37.3%;P<0.001)done in patients living in those States.Listings pmp in the Mexican States with high LT activity were 3.8,1.5 vs 1.2,0.6(P<0.001);observed-to-expected listings were 1.3,0.4 vs 0.4,0.2(P<0.001);LT pmp were 2.7,0.9 vs 0.7,0.5(P<0.001).After controlling for other variables,patients living in high LT activity States had a HR 1.14(95%CI:1.03-1.26;P=0.009)to be a case of transplantation after listing.CONCLUSION Geographic disparities substantially affect LT access in Mexico.The population living near Transplant Centers has a 3.2-fold higher access to the waiting list and a 3.8-fold higher likelihood of LT.Current referral system,and resource allocation need urgent revision to remove the barriers associated with geographic disparity.
文摘On the morning of October 15,people from different countries will queue up at the entrance of Centro Banamex,the international convention and exhibition center in Mexico.There are local dealers present,Brazilian builders identifiable by their yellow-green,fluorescent vests,Canadian buyers carrying computer bags,and a group of Chinese individuals with aluminum alloy suitcases labeled“Foshan Ceramics”,“Yongkang Hardware”,and“Anji Bamboo Floor”.
文摘Liver transplantation(LT)is the only curative treatment for end-stage liver disease.Although Mexico has made important strides in surgical capacity and institutional development,the country continues to report one of the lowest LT rates in Latin America.Multiple challenges remain,including inequitable access to care,limited organ donation,and structural inefficiencies in allocation systems.To review the current status of LT in Mexico,describe historical trends,highlight significant barriers to progress,and discuss potential opportunities for program expansion.We conducted a narrative review incorporating data from the National Transplant Center(Centro Nacional de Trasplantes in Spanish),relevant peer-reviewed literature,and global benchmarks.The analysis focused on trends in liver transplant volume,donor types,etiology shifts,institutional disparities,and the impact of the coronavirus disease 2019(COVID-19)pandemic.LT activity in Mexico increased from 25 transplants in 1999 to 297 in 2023.However,over 68%of transplants are concentrated in Mexico City,and only eight centers perform more than ten LTs per year.Deceased donors account for most grafts,while living donor transplants remain rare and mostly limited to private institutions.The national waiting list functions primarily as a registry rather than a priority-based allocation system.The COVID-19 pandemic further disrupted transplant programs,particularly in the public sector.Innovative approaches such as donation after circulatory death,hepatitis C virus-positive donor utilization,and advanced perfusion technologies are currently unavailable or underutilized in Mexico.Mexico's LT system faces geographic,regulatory,and resource-related limitations.To improve outcomes and ensure equitable access,strategic reforms focused on donor expansion,centralized allocation,perfusion technologies,and standardization of care are urgently needed.
文摘Genomic medicine has evolved significantly,merging centuries of scientific progress with modern molecular biology and clinical care.It utilizes knowledge of the human genome to enhance disease prevention,diagnosis,treatment,and potential reversal.Genomic medicine in hepatology is particularly promising due to the crucial role of the liver in several metabolic processes and its association with diseases such as metabolic dysfunction-associated steatotic liver disease,type 2 diabetes mellitus,liver cirrhosis,and cardiovascular conditions.The mid-20th century witnessed a paradigm shift in medicine,marked by the emergence of molecular biology,which enabled a deeper understanding of gene expression and regulation.This connection between basic science and clinical practice has enhanced our knowledge of the role of gene-environment interactions in the onset and progression of liver diseases.In Latin America,including Mexico,with its genetically diverse and admixed populations,genomic medicine provides a foundation for personalized and culturally relevant health strategies.This review highlights the need for genomic medicine,examining its historical evolution,integration into hepatology in Mexico,and its potential applications in the prevention of chronic diseases.It emphasizes the importance of training in genomic literacy and interdisciplinary education in medical training,particularly in the field of hepatology,with a focus on genomic medicine expertise.
文摘The September 2017 earthquakes in Mexico,which struck within a twelve-day span and affected regions with vastly different seismic,socioeconomic,and urban characteristics,revealed the multifactorial nature of seismic vulnerability and resilience in the country.This paper provides a comprehensive review of the damage on the built environment,emergency response,recovery and reconstruction efforts,regulatory evolution,and institu-tional reforms that followed these events.Key topics include the performance of self-built housing and essential infrastructure,the challenges of decentralized building codes and their uneven development and enforcement,the role of civil society,private sector and media in disaster response,and the implementation of the National Reconstruction Program.Advances in seismic code development-particularly the updated Complementary Technical Norms(CTNs)of Mexico City-and the creation of a dedicated standard for the evaluation and rehabilitation of existing buildings are also discussed.The proposed Construction Law for Mexico City,which aims to assign legal responsibility to stakeholders and formalize the regulatory framework,may serve as a legislative model for other regions.The paper concludes by highlighting the importance of coordination,tech-nical rigor,equity and inclusion in recovery and reconstruction,and public engagement in advancing seismic resilience across diverse urban,semi-urban and rural contexts.
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This paper compares monthly and seasonal rain rates derived from the Version 5 （V5） and Version 6 （V6） TRMM Precipitation Radar （TPR, TSDIS reference 2A25）, TRMM Microwave Imager （TMI, 2A12）, TRMM Combined Instrument （TCI, 2B31）, TRMM calibrated IR rain estimates （3B42） and TRMM merged gauge and satellite analysis （3B43） algorithms over New Mexico （NM） with rain gauge analyses provided by the New Mexico water districts （WD）. The average rain rates over the NM region for 1998- 2002 are 0.91 mm d^-1 for WD and 0.75, 1.38, 1.49, 1.27, and 1.07 mm d^-1 for V5 3B43, 3B42, TMI, PR and TCA; and 0.74, 1.38, 0.87 and 0.97 mm d^-1 for V6 3B43, TMI, TPR and TCA, respectively. Comparison of V5 3B43 with WD rain rates and the daily TRMM mission index （TPR and TMI） suggests that the low bias of V5 3B43 for the wet months （summer to early fall） may be due to the non-inclusion of some rain events in the operational gauge analyses that. are used in the production of V5 3B43. Correlation analyses show that the WD rain rates vary in phase, with higher correlation between neighboring WDs. High temporal correlations （〉0.8） exist between WD and the combined algorithms （3B42, 3B43 and TCA for both V5 and V6） while satellite instrument algorithms （PR, TMI and TCI） are correlated best among themselves at the monthly scale. Paired t-tests of the monthly time series show that V5 3B42 and TMI are statistically different from the WD rain rates while no significant difference exists between WD and the other products. The agreements between the TRMM satellite and WD gauge estimates are best for the spring and fall and worst for winter and summer. The reduction in V6 TMI （-7.4%） and TPR （-31%） rain rates （compared to V5） results in better agreement between WD estimates and TMI in winter and TPR during summer.
基金Supported by National Council of Science and Technology(CONACYT-FONDO SECTORIALMexico)+7 种基金Grant No.Salud-2010-1-139085to Roman SJalisco State Council of Science and Technology(COECYTJAL-Universidad de GuadalajaraGuadalajaraJaliscoMexico)Grant No.2009-1-06-2009-431to Panduro A
文摘Hepatitis B virus(HBV)genotypes have distinct genetic and geographic diversity and may be associated with specific clinical characteristics,progression,severity of disease and antiviral response.Herein,we provide an updated overview of the endemicity of HBV genotypes H and G in Mexico.HBV genotype H is predominant among the Mexican population,but not in Central America.Its geographic distribution is related to a typical endemicity among the Mexicans which is characterized by a low hepatitis B surface antigen seroprevalence,apparently due to a rapid resolution of the infection,low viral loads and a high prevalence of occult B infection.During chronic infections,genotype H is detected in mixtures with other HBV genotypes and associated with other co-morbidities,such as obesity,alcoholism and co-infection with hepatitis C virus or human immunodeficiency virus.Hepatocellular carcinoma prevalence is low.Thus,antiviral therapy may differ significantly from the standard guidelines established worldwide.The high prevalence of HBV genotype G in the Americas,especially among the Mexican population,raises new questions regarding its geographic origin that will require further investigation.
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.
基金Under the auspices of Mexican National Council for Science and Technology (No 2008-01-87972)
文摘Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide.Identifying the driving factors and understanding the contribution of each factor are essential for the management of forest fire occurrence.The objective of this study is to identify variables that are spatially related to the occurrence and incidence of the forest fire in the State of Durango,Mexico.For this purpose,data from forest fire records for a five-year period were analyzed.The spatial correlations between forest fire occurrence and intensity of land use,susceptibility of vegetation,temperature,precipitation and slope were tested by Geographically Weighted Regression(GWR) method,under an Ordinary Least Square estimator.Results show that the spatial pattern of the forest fire in the study area is closely correlated with the intensity of land use,and land use change is one of the main explanatory variables.In addition,vegetation type and precipitation are also the main driving factors.The fitting model indicates obvious link between the variables.Forest fire was found to be the consequence of a particular combination of the environmental factors,and when these factors coexist with human activities,there is high probability of forest fire occurrence.Mandatory regulation of human activities is a key strategy for forest fire prevention.
基金World Wildlife Fund (WWF) for providing financial support for the conduction of the research through Oaxaca Community Foundationthe National Council for Science and Technology supported the first author through grant for two years
文摘Re-vegetation plays a fundamental role for erosion control and plant recovery in lands affected by gully erosion. Bioengineered practices facilitate the gullies rehabilitation. Objectives of the research were: 1) Identify taxonomically the pioneer vegetation on each gully section; 2) Characterize vegetation distribution preferences and 3) Assess structural/functional traits to recognize erosion control key species. Bioengineering was applied in a watershed belonging to Sierra Madre del Sur, at Oaxaca, Mexico, on eight gullies, with local support and minimal investment. "La Mixteca" is a poor ecological and socio-economic region, comparable to other regions of the world. The Initial Floristic Composition(IFC) inventory is the baseline of the successional process. The transect method was used to determine the colonization of species. Cover abundance of registered species was estimated using the semi-quantitative scale of Braun-Blanquet. This procedure was repeated in five different positions(floor, hillslopes and tops), in the cross section of the gully. Throughcorrespondence analysis and clustering, the distribution of species was analyzed. Adequate responses were obtained in soil retention(quantity) and plant cover(existence and diversity); as measurable indicators of the bioengeneering works efficiency. Occupation of soil by native species from the Tropical Deciduous Forest was favored using live barriers. We detected species guilds with spatial distribution preferences in the gullies cross section. Plant cover characterization includes: native colonizer species, herbaceous, shrubby and trees of the forest community bordering the gully area, with cover abundance and structural/functional traits, useful to protect degraded areas. This spatial occupation process of plants responds to a secondary succession in gullies, where the proposed IFC model is correctly represented through bioengineering. Natural establishment of plants was successful by traits of species such as extensive root system and sexual/vegetative reproduction.
文摘In October 1999, rainfall induced landslides devastated different communities of the Sierra Norte, Puebla, causing more than 250 victims and economic losses greater than $ 450 million. The town of Zacapoaxtla was one of the sectors most affected by slope instability due to the existing geological features and geomorphic characters determined by material properties, landforms and processes. Extensive areas formed by pyroclastic piedmonts developed on the Quaternary volcanic ignimbrite deposits highly dissected by marginal gully erosion combined with an extreme rainfall event played a significant role as an ideal scenario for the occurrence of landsliding. Distribution of landslides triggered by rainfall within the main sector of the Zacapoaxtla municipality was analyzed by using IKONOS images in terms of exploring the likely relationship between mass movement incidence and levels of vegetation density. The later was undertaken by means of producing an NDVI and applying a fragmentation algorithm. Finally, a map of potential areas of mass movements risk was produced based on the combination of a socio-economic vulnerability index, geologic and geomorphological maps and the spatial landslide distribution.
文摘Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo, Mexico some oak trees were heavily infested by honeydew-producing insects （family Margarodidae, tribe Xylococcini, genus Strigmacoccus） and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honey- dew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such re- sources. Four hummingbird species consumed this resource （Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens）. Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the dally times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively
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.
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The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission for the Knowledge and Use of Biodiversity(CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost(erosion) or gained(accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time;coastline change rates having duplicated between the earliest(1970/81–2005) and the two more recent(2005–2010, and 2010–2015) analysed time periods, with erosion rates for each corresponding period of –3 m/yr,–7.5 m/yr, and –7.3 m/yr,and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.
