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PubMed2003

Survey of black howler (Alouatta pigra) and spider (Ateles geoffroyi) monkeys in the Mayan sites of Calakmul and Yaxchilán, Mexico and Tikal, Guatemala.

Surveys of populations of spider and howler monkeys were conducted at the Mayan sites of Calakmul and Yaxchilán, Mexico and Tikal, Guatemala. The forests in which these sites are found are part of the largest landmass of tropical rain forests present in Mesoamerica, encompassing about 4 million ha. Triangulation of monkey vocalization combined with ground surveys was used to determine the presence of howler and spider monkey groups. Howler monkey mean troop size at these sites varied from 6.6+/-2.1 individuals in Yaxchilán to 7.5+/-1.9 in Calakmul to 8.7+/-2.2 in Tikal. Density estimates varied from 12.8 individuals/km(2 )in Yaxchilán to 15.2 individuals/km(2 )in Calakmul to 17.8 individuals/km(2 )in Tikal. Mean spider monkey subgroup size varied from 4.7+/-2.6 individuals in Tikal to 5.6+/-3.0 individuals in Yaxchilán to 7.7+/-3.8 individuals in Calakmul. Spider monkey density varied from 17.0 individuals/km(2 )in Yaxchilán to 17.2 individuals/km(2 )in Calakmul to 56.4 individuals/km(2 )in Tikal. All sightings of both howler and spider monkeys at the three sites were in undisturbed rain forest vegetation and spider monkeys in general were more frequently sighted at higher tree heights than howlers. We discuss the value of further acquiring data on howler and spider monkey populations existing in extensive forest tracts and on the conservation value for both primate species of the forests surrounding the Mayan ruins found in this area of Mesoamerica.

Alouatta↗
PubMed2006

Feasibility and use of school-based condom availability programs in Tijuana, Mexico.

Condom availability programs (CAPs) may increase access to condoms and contribute to increased condom use among youth. This study describes the characteristics, degree of satisfaction, and gender differences among users of a CAP implemented in two high schools in Tijuana (Baja California, Mexico). A kiosk distributing free male condoms was set up in two high schools in Tijuana. Kiosk users (N=570) were more likely to be male, young, and/or enrolled in a lower SES school. Most kiosk users were either sexually active or planning to have sex. Females were less likely to request condoms and to continue using the kiosk, but more likely to request information on other contraceptive methods. Results demonstrate the feasibility of implementing CAPs in Mexican schools and suggest that these programs can improve adolescents' condom access.

Adolescent↗
PubMed2007

A qualitative exploration of gender in the context of injection drug use in two US-Mexico border cities.

Injection drug use is of increasing concern along the U.S.-Mexico border where Tijuana and Ciudad (Cd.) Juarez are located. We conducted a qualitative study to explore the context of drug use, with a focus on gender differences. In-depth interviews were conducted with 10 male and 10 female injection drug users (IDUs) in Tijuana and 15 male and 8 female IDUs in Cd. Juarez. Topics included types of drugs used, injection settings, access to sterile needles and environmental influences. Interviews were taped, transcribed and translated. Content analysis was conducted to identify themes. Several themes emerged with respect to gender: (a) how drugs were obtained; (b) where drugs were used; (c) relationship dynamics surrounding drug use; and (d) sex in exchange for money or drugs. Men reported buying and injecting in shooting galleries and other locations, whereas women tended to buy and inject drugs with people they knew and trusted. All men reported having shared syringes in shooting galleries, often with strangers. In these two cities, venue-based interventions may be more appropriate for male IDUs, whereas personal network interventions may be more appropriate among female IDUs.

Adult↗
PubMed2005

Social support mobilization and deterioration after Mexico's 1999 flood: effects of context, gender, and time.

Samples of adults representative of Teziutlán, Puebla, and Villahermosa, Tobasco, were interviewed 6, 12, 18, and 24 months after the devastating 1999 flood and mudslides. The interview contained multiple measures of social support that had been normed for Mexico. Comparisons between sample data and population norms suggested minimal mobilization of received support and substantial deterioration of perceived support and social embeddedness. Social support was lowest in Teziutlán, which had experienced mass casualties and displacement, and among women and persons of lower educational attainment. Disparities according to gender, context, and education grew larger as time passed. The results provide compelling evidence that the international health community must be mindful of social as well as psychological functioning when disasters strike the developing world.

Adult↗
PubMed2006

Rural-urban health care provider disparities in Alaska and New Mexico.

Compared to their urban counterparts, rural residents face numerous disparities in obtaining health care, including limited access to care providers. We assessed disparities in provider availability in rural versus urban Alaska and New Mexico, with emphasis on professionals likely to provide mental health care. Using lists of licenses, we categorized physical and mental health care providers into rural versus urban and calculated rural versus urban disparity ratios. Rural residents had significantly less access to health care providers and discrepancies grew with level of required provider education and specialization. Addressing disparities via creative strategies is crucial to improving rural care delivery.

Alaska↗
PubMed2006

Heavy metal accumulation in four species of sea turtles from the Baja California peninsula, Mexico.

Heavy metals were assessed in four species of sea turtles from the Baja California Peninsula, Mexico, representing the first report of heavy metal concentrations in tissues of post-yearling sea turtles from the Eastern Pacific. Concentrations of Cd measured in C. mydas kidney (653 microg/g dry wt) were the highest ever reported for any sea turtle species. Cd accumulated preferentially in kidney and the ratios of kidney to liver Cd in Baja California turtles were among the highest reported for sea turtles globally. Zn, Ni, and Mn concentrations were also significantly higher in kidney than other tissues, while Cu and Fe were greatest in liver, and all metals were lowest in muscle. With the exception of one value (69.9 microg/g in kidney of C. caretta), Pb was low in all tissues from Baja California. In comparisons across species, kidney of C. mydas had greater Zn and Ni concentrations as compared to other species, although there was no difference in liver metal levels among the species. Positive correlations were detected in the concentrations of Cd, Cu and Ni with the straight carapace length of C. caretta.

Animals↗
PubMed2005

Prevalence of hepatitis C infection in a population of asymptomatic people in a checkup unit in Mexico city.

Hepatitis C virus (HCV) infection has an estimated prevalence of 3% around the world. Unfortunately, many persons with HCV infection are asymptomatic. The aim of this study was to determine the prevalence of hepatitis C Virus infection in asymptomatic persons. This study was carried out in a population-based cross-sectional study in the Checkup Unit of University Hospital in Mexico City. Patients with two or more HCV risk factors were studied. Serum specimens from all patients were screened for HCV RNA by qualitative polymerase chain reaction (PCR). HCV RNA-positive serum was also screened by quantitative PCR and for HCV genotype. Three hundred asymptomatic people were included, 194 men and 106 women, with a mean age of 46.8+/-11.9. Six (2%) of the 300 people were positive and viremic. The most common risk factors in positive patients were manicures or pedicures with a nonpersonal instrument and more than three sexual partners. We concluded that hepatitis C is frequent in asymptomatic people, and those people are often viremic. In addition, this study suggests that the spectrum of liver disease in asymptomatic and newly diagnosed HCV-positive persons is broad.

Adult↗
PubMed2006

Geochemistry of leachates from the El Fraile sulfide tailings piles in Taxco, Guerrero, southern Mexico.

Leachates from the El Fraile tailings impoundment (Taxco, Mexico) were monitored every 2 months from October 2001 to August 2002 to assess the geochemical characteristics. These leachates are of interest because they are sometimes used as alternative sources of domestic water. Alternatively, they drain into the Cacalotenango creek and may represent a major source of metal contamination of surface water and sediments. Most El Fraile leachates show characteristics of Ca-SO(4), (Ca+Mg)-SO(4), Mg-SO(4 )and Ca-(SO(4)+HCO(3)) water types and are near-neutral (pH=6.3-7.7). Some acid leachates are generated by the interaction of meteoric water with tailings during rainfall events (pH=2.4-2.5). These contain variable levels of SO(4) (2-) (280-29,500 mg l(-1)) and As (<0.01-12.0 mg l(-1)) as well as Fe (0.025-2,352 mg l(-1)), Mn (0.1-732 mg l(-1)), Zn (<0.025-1465 mg l(-1)) and Pb (<0.01-0.351 mg l(-1)). Most samples show the highest metal enrichment during the dry seasons. Leachates used as domestic water typically exceed the Mexican Drinking Water Guidelines for sulfate, hardness, Fe, Mn, Pb and As, while acidic leachates exceed the Mexican Guidelines for Industrial Discharge Waters for pH, Cu, Cd and As. Speciation shows that in near-neutral solutions, metals exist mainly as free ions, sulfates and bicarbonates, while in acidic leachates they are present as sulfates and free ions. Arsenic appears as As((V)) in all samples. Thermodynamic and mineralogical evidence indicates that precipitation of Fe oxides and oxyhydroxides, clay minerals and jarosite as well as sorption by these minerals are the main processes controlling leachate chemistry. These processes occur mainly after neutralization by interaction with bedrock and equilibration with atmospheric oxygen.

Geological Phenomena↗
PubMed2005

Air emissions assessment from offshore oil activities in Sonda de Campeche, Mexico.

Air emission data from offshore oil platforms, gas and oil processing installations and contribution of marine activities at the Sonda de Campeche, located at the Gulf of Mexico, were compiled and integrated to facilitate the study of long range transport of pollutants into the region. From this important region, roughly 76% of the total Mexican oil and gas production is obtained. It was estimated that the total air emissions of all contaminants are approximately 821,000 tons per year. Hydrocarbons are the largest pollutant emissions with 277,590 tons per year, generated during flaring activities, and SOx in second place with 185,907 tons per year. Marine and aviation activities contribute with less than 2% of total emissions. Mass of pollutants emitted per barrel of petroleum produced calculated in this work, are in the range reported by similar oil companies.

Air Pollutants↗
PubMed2005

Assessment of MODIS-EVI, MODIS-NDVI and VEGETATION-NDVI composite data using agricultural measurements: an example at corn fields in western Mexico.

Although several types of satellite data provide temporal information of the land use at no cost, digital satellite data applications for agricultural studies are limited compared to applications for forest management. This study assessed the suitability of vegetation indices derived from the TERRA-Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and SPOT-VEGETATION (VGT) sensor for identifying corn growth in western Mexico. Overall, the Normalized Difference Vegetation Index (NDVI) composites from the VGT sensor based on bi-directional compositing method produced vegetation information most closely resembling actual crop conditions. The NDVI composites from the MODIS sensor exhibited saturated signals starting 30 days after planting, but corresponded to green leaf senescence in April. The temporal NDVI composites from the VGT sensor based on the maximum value method had a maximum plateau for 80 days, which masked the important crop transformation from vegetative stage to reproductive stage. The Enhanced Vegetation Index (EVI) composites from the MODIS sensor reached a maximum plateau 40 days earlier than the occurrence of maximum leaf area index (LAI) and maximum intercepted fraction of photosynthetic active radiation (fPAR) derived from in-situ measurements. The results of this study showed that the 250-m resolution MODIS data did not provide more accurate vegetation information for corn growth description than the 500-m and 1000-m resolution MODIS data.

Crops, Agricultural↗
PubMed2006

Assesment of trace elements and organic pollutants from a marine oil complex into the coral reef system of Cayo Arcas, Mexico.

Possible contaminants produced by the Petroleos Mexicanos (PEMEX) marine oil complex in the vicinity of the Cayo Arcas (Mexico) coral reef ecosystem were evaluated by analyzing sediments and sea water for hydrocarbons and metal elements. We found that the concentrations of aliphatic hydrocarbons in the sea water were generally low, with the highest values detected near the oil station; the concentration of polycyclic aromatic hydrocarbons (PAHs) was generally below the detection limit. The hydrocarbons found in the sediments seem to have a pyrogenic origin, and were probably produced by marine traffic in the study area. The total PAH concentration did not exceed the NOAA criteria, although levels of some individual PAHs did. The only metal detected in the sea water at high concentrations was nickel. The Ni/V ratio in the sediments indicates the contribution of crude oil to the system. The high content of Ni and Zn was attributed to the ballast waters from the oil tankers that load at the station's monobuoys. The presence of fine sediments that commonly originate from terrestrial ecosystems supported this assumption.

Animals↗
PubMed2006

Telemetric system for hydrology and water quality monitoring in watersheds of northern New Mexico, USA.

This study utilized telemetric systems to sample microbes and pathogens in forest, burned forest, rangeland, and urban watersheds to assess surface water quality in northern New Mexico. Four sites included remote mountainous watersheds, prairie rangelands, and a small urban area. The telemetric system was linked to dataloggers with automated event monitoring equipment to monitor discharge, turbidity, electrical conductivity, water temperature, and rainfall during base flow and storm events. Site data stored in dataloggers was uploaded to one of three types of telemetry: 1) radio in rangeland and urban settings; 2) a conventional phone/modem system with a modem positioned at the urban/forest interface; and 3) a satellite system used in a remote mountainous burned forest watershed. The major variables affecting selection of each system were site access, distance, technology, and cost. The systems were compared based on operation and cost. Utilization of telecommunications systems in this varied geographic area facilitated the gathering of hydrologic and water quality data on a timely basis.

Environmental Monitoring↗
PubMed2006

Eutrophication and sedimentation patterns in complete exploitation of water resources scenarios: an example from Northwestern semi-arid Mexico.

Water requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the demand during--not only--scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates extremely between rises and downward during one single year. Besides of water management implications, changes on physical, chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 +/- 0.70 and 0.14 +/- 0.12 mg P l(-1)), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms, including nutrient release from the sediment-water interface as the main nutrient pathway when shallowness, at the same time as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids (mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m(-2) year(-1) with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 +/- 0.40 cm year(-1)) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation (9,895 tons km(-2) year(-1)) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures.

Chlorophyll↗
PubMed2005

Musculoskeletal pain among women of menopausal age in Puebla, Mexico.

Worldwide, complaints of musculoskeletal pain are more frequent than complaints of hot flashes amongst women of menopausal age. The purpose of this study was to examine musculoskeletal pain among women of menopausal age in the city of Puebla, Mexico. An opportunity sample was recruited from public parks and markets, with representation from all social classes (n=755). Mean age was 50.1 years, and the majority were employed as saleswomen in small businesses. Symptom frequencies were collected by open-ended interviews and with a structured symptom list that queried symptom experience during the two weeks prior to interview. In response to open-ended questions, "dolores de huesos" (bone pain) was volunteered by 47% of respondents as a symptom associated with menopause, second only to hot flashes (53%). From the structured symptom list, 55.8% and 55.6% reported back pain and joint stiffness during the two weeks prior to interview. Women with back pain and joint stiffness were less likely to report being active during their leisure time (p<.01). The results of backwards stepwise logistic regressions indicate that women with back pain were more likely to be older, with less education, a higher BMI, and ate less meat. Women with joint pain were more likely to be post-menopausal, with less education, more children, a higher BMI, and were likely to drink milk and coffee more than once/week but less than once/day. While menopause is not necessarily a risk factor for musculoskeletal pain, it is important to recognize the pervasiveness of this complaint among women of menopausal age.

Adult↗
PubMed2006

Mycotoxins in Mexico: epidemiology, management, and control strategies.

Mycotoxin-producing molds species are extremely common. Many of them provoke serious diseases in humans and animals. These toxins occur, with varying severity, in agricultural products. Since Mexico is a big crops producer, the importance of the presence of these toxins is high. Currently, the Mexican regulation establishes limits only for aflatoxins in cereals and cereal products. No limits are set for other mycotoxins. Epidemiological data although limited, has shown that an important number of samples contain mycotoxin limits above those established abroad. Several strategies for reducing contamination have been conducted in the country such as development of hybrid corn, control of insect population, use of natural products, and modification of nixtamalization and extraction procedures. Although significant research on this field has been conducted, there is still a great need for information to determine the incidence of mycotoxins in Mexican products.

Aflatoxins↗
PubMed2005

Atactorhynchus duranguensis n. sp. (Acanthocephala: Atactorhynchinae) from Cyprinodon meeki (Pisces: Cyprinodontidae) near Durango, Mexico.

Atactorhynchus duranguensis n. sp. (Acanthocephala: Atactorhynchinae) is described from the intestine of Cyprinodon meeki Miller, an endemic freshwater fish from a far-inland locality of Mexico. Diagnostic features include: body small, stout, ventrally curved; small cylindrical proboscis armed with 16 alternating vertical rows of four or five hooks; anterior two or three hooks conspicuous, stout and larger than other hooks, and have large, rod-shaped roots with a markedly and abruptly enlarged base; three posterior hooks of each row are smaller and rootless; single-walled proboscis receptacle; lemnisci equal in length, elongate and robust; and cement gland syncytial, larger than testis. The new species is smaller than A. verecundus Chandler, 1935, the only previously described species in the genus. The shape of the proboscis of the new species is strikingly different from that of A. verecundus, which is widest at the apex. Likewise, the greatest width of the trunk of the new species is in about the middle, differing from that of A. verecundus where the trunk is widest posteriorly. The new species also can be distinguished from A. verecundus because of its much smaller hook lengths and slightly smaller proboscis. In addition, the proportion of large apical proboscis hooks in relation to the small basal hooks is different: the basal hooks of A. verecundus are about half the size of the anterior hooks and but only about a quarter of the size in A. duranguensis. Unlike A. verecundus, the base of the roots are markedly and abruptly enlarged in the new species. Finally, the eggs of the new species are smaller (23-27 x 8-10 microm) than those of A. verecundus (27-30 x 12-13 microm).

Acanthocephala↗
PubMed2005

Gorgoderina festoni n. sp. (Digenea: Gorgoderidae) in Anurans (Amphibia) from Mexico.

Gorgoderina festoni n. sp. is described from the urinary bladder of Gastrophryne usta, Leptodactylus labialis, L. melanonotus and Bufo marinus from localities at low altitude in the states of Veracruz, Oaxaca, Guerrero and Colima, Mexico. This species differs from most other species of the genus by a combination of the following characters: lobed vitelline masses, body size 3.45-4.26 (mean 3.75) mm and sucker-ratio 1:1.3-1.52 (mean 1:1.44). The new species shares these three features with G. bilobata Rankin, 1937, G. schistorchis Steelman, 1938, G. tenua Rankin, 1937, G. vitelliloba (Olsson, 1876) and G. cryptorchis Travassos, 1924, but it differs from the first four in having gonads with entire margins. G. festoni most closely resembles G. cryptorchis, but differs from this species in body width at the level of the ventral sucker and in the absence of oesophageal glands. The autapomorphy that distinguishes G. festoni from all other members of the genus is the presence of a tegumental extension (festoon) on the external margin of the ventral sucker.

Animals↗
PubMed2005

Economic contribution of draught animals to Mazahua smallholder Campesino farming systems in the highlands of Central Mexico.

The economic contribution of draught animals to smallholder Mazahua campesino systems in two mountain villages of San Felipe del Progreso, in the central highlands of Mexico, was assessed. Campesinos rely on draught animals for cultivation tasks, as pack animals, and as transport for agricultural and domestic activities. The villages were San Pablo Tlalchichilpa (SPT) and La Concepción Mayorazgo (LCM). Twelve households that possessed draught animals were monitored from July 1999 to June 2000, nine in SPT and three in LCM, in terms of animal inventories and income from their draught animals, in cash and opportunity values. Equines in SPT have substituted bulls, and are recognized for their multipurpose contribution, while in LCM bulls are still used for ploughing the land. Overall total mean gross income was US dollar 490.78 per farm per year, plus US dollar 56 as opportunity value of the fertilizer value of manure for both villages. Deducting estimated costs, owning draught animals leaves a mean net margin of US dollar 412.50/year in SPT and of US dollar 285.64/year in LCM. There is a significant correlation (p < 0.05) between ownership of draught animals and incomes, with a regression coefficient of US dollar 279.16 per year per draught animal. Besides positive economic returns, having work animals alleviates drudgery for the campesino families.

Agriculture↗