Merida City Research Articles

Family migration and physical growth in Merida, Yucatan, Mexico

Merida city in Yucatan, Mexico, has received rural-to-urban migration for decades, with most immigrants settling in the city's southern neighborhoods. Exposure of immigrants to new environmental and sociocultural conditions can generate biological responses, including changes in physical growth pattern at early age. We performed a study to identify and measure the effects of family migration into south Merida on growth in 4- to 6-year-old children, measuring weight, height, sitting height, and calculated arm muscle and fat areas of 445 children: 228 natives (116 females) and 217 immigrants (118 females) and collecting family social and demographic data. Statistical analysis focused on determining differences in growth, socioeconomic, and biological variables by migratory condition and generating multiple regression models for each growth measurement. No univariate statistical differences (P > 0.05, Student's t-test) were observed in growth between studied children. Multiple regression analyses showed age, sex, mother's height, birth order, birth weight, family income, zone of residence, diet, and febrile episodes had an effect on growth. Neither the migration variable used above nor any other definition of migrant had a significant effect on growth. The lack of differences in growth between immigrant and native children is probably due to similarity in socioeconomic conditions of their families.

A Survey of Dog Populations in Urban and Rural Areas of Yucatan, Mexico

ABSTRACTA survey in a major Mexican city (Merida) and three rural communities was conducted to generate information regarding the size and structure of the owned-dog populations and people's opinions about the dogs and how they took care of them. Household characteristics and dog population size, health and reproductive issues were compared between the two kinds of communities: urban and rural. A telephone survey was conducted in Merida city whereas personal interviews were used in the rural communities. Local veterinarians were also interviewed to evaluate their influence on the dog populations in Merida city. The ratio of people to dogs was 3.4:1 in the city, and 1.7:1 to 4.6:1 in the different rural communities. In general it was more common to find a dog-owning household in the city of Merida (72.8%) than in the rural areas (63.6%, 65.5% and 71.1%), and in the city more households had adequate fences to restrain dogs. Larger families were more likely to own a dog than small families. Households of medium socio-economic status had a significantly higher probability of owning a dog than households of low or high socio-economic status. Of the dogs in the city, 90.1% were vaccinated against rabies compared with 62.3% of the dogs in the rural communities. Most animals were intact; the frequency of neutering/spaying was 3.1% in Merida and 1.8% in the rural communities. Few private veterinary practitioners were involved in the control of dog overpopulation. It is concluded that dogs are popular pets both in urban and rural Yucatan. People's opinions about dogs and the level of supervision varied with socio-economic status, and people in the city provided better food, shelter and preventive medicine. The veterinary practitioners did little to promote the control of dog breeding or to reduce the relinquishing of unwanted dogs in the city. Better client education and the promotion of sterilization of pets at low cost would improve the situation.

Detección de metales pesados y dicloro difenil tricloro etano (DDT) en músculos y órganos de bovinos en Yucatán

The purpose of this research was to determine copper (Cu), lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), dichlorodiphenyl-trichloroethane (DDT), and DDT metabolites, in the muscles and organs of cattle slaughtered in Merida, Yucatan, Mexico, during 13 months. Pectoral muscle, kidney and liver were sampled in the Faculty of Veterinary Medicine and Animal Husbandry Processing Plant (RVet) (n=255), and in Merida City Municipal Slaughter House (RMun) (n=225), from April 2001 to April 2002. Samples were analyzed using an atomic absorption spectrophotometer provided with hollow cathode lamps and an air-acetylene burner to determine Cu, Pb, and Cd, or by means of the use of cold vapor for Hg, or finally using a hydride generator for As. DDT and DDT metabolites were determined using a gas chromatographer with an electron capture detector. Results were analyzed calculating the general means and dispersion parameters as well as using the least square method to detect the effects of sample type, abattoir and season of the year, as well as all interactions. Cu content in 79 % of all the samples was higher than the limit recommended by Mexican Official Norms (MON's). The quantity was highest in liver samples. Cu levels were higher (P<0.05) in RVet during December to April. A great variability was found in Pb and most of the samples had a quantity higher that the one permitted by the MON's. Cd levels were lower than those allowed by the MON's. No Hg, As, DDT or DDT metabolites were found.

Comparación de la atención del parto normal en los sistemas hospitalario y tradicional

Objective. To compare vaginal delivery hospital and traditional care systems to identify resources and practices, as well as maternal and neonatal complications related to each system. Material and Methods. Between 1989 and 1990, a cross-sectional study was conducted in three hospitals of Merida City and four municipalities of the state of Yucatan. The study sample consisted of 205 women who had a normal vaginal delivery. Delivery procedures were observed and a questionnaire to identify complications was applied 15 days after childbirth. Data analysis consisted in comparison of proportions with the chi-squared test. Results. Maternal and neonatal complications were identified in both systems; however, maternal complications were more frequent in hospital care, whereas neonatal complications were more frequent in traditional delivery care. The total number of complications was similar in the two systems. Conclusions. No difference was found in the quality of care between the hospital and the traditional systems. Observed complications may be attributable to resources and practices of each system. Additional studies should be conducted to evaluate the advantages and disadvantages of each system, as well as to improve the quality of maternal and child care. The English version of this paper is available at: http://www.insp.mx/salud/index.html

New Species of Ramalina from Venezuela

Eight new species of Ramalina are described from Venezuela: R. andina V. Marcano & A. Morales, R. chiguarensis V. Marcano & A. Morales, R. crispata A. Morales & V. Marcano, R. lopezii A. Morales & V. Marcano, R. microphylla A. Morales & V. Marcano, R. santanensis A. Morales & V. Marcano, R. tenuissima V. Marcano & A. Morales, and R. tovarensis V. Marcano & A. Morales. The genus Ramalina Ach. is represented in Venezuela by over 30 described species. Ramalina spp. are present in most vegetation types, including lowland, highlands (tepuy), heathlands and woodlands, rain forests, and alpine moorlands (paramos), and occur on rocks, peaty soil, wood, or bark. During a taxonomic revision of Venezuelan members of Ramalina we encountered several undescribed species, eight of which are described below. They are very distinctive species and have been collected only recently in poorly known areas, such as the Peninsula de Paraguana in the State of Falc6n, and in the Andes, both of which possess a high diversity of lichens. MATERIALS AND METHODS The species described below are based on material collected by Antonio Morales, Lopez-Figueiras, and Vicente Marcano in Venezuela in the states of Falc6n, Merida, Taichira, and Trujillo. The specimens cited in this paper are deposited in MERF and VEN. Chemical data were obtained by thin-layer chromatography (TLC) by means of standard methods (White & James 1985) and by isolation with petroleum ether, benzene, and acetone of chemical compounds for comparison from Ramalina usnea (L.) Howe, R. pusiola Muill. Arg., and Cladonia cryptochlorophaea Asah. The substances isolated were usnic, salazinic, stictic, protocetraric, divaricatic, and cryptochlorophaeic acids. These compounds were identified by comparison of their physical and spectroscopical (IR) properties with reports in the chemical literature (Culberson 1969; Culberson et al. 1977). In the case of the mixture sekicaic and homosekicaic acids the compounds were identified by discrimination of the 1HNMR and 13C-NMR signals. The employed instruments were: Jeol GSX 270 FT-NMR and VARIAN FT-80-A (Morales & Marcano 1992). Freezing microtome sections ofthalli and apothecia were mounted in lactophenol/cotton blue and examined by light microscopy (LM). THE SPECIES RAMALINA ANDINA V. Marcano & A. Morales sp. nov. (FIG. 1-2) Thallus corticolus, pendulus; laciniae subnitidae, complanatae vel canaliculatae; pseudocyphelliis ellipsoideis instructis; soralia lateralia vel laminalia; pycnidia non visa; apothecia non visa; acidum salazinicum continens. TYPus: VENEZUELA. EDO. MERIDA. La Carbonera, etween La Azulita and Merida City, 2,200 m, 1 March 1975, Lopez-Figueiras & Keogh 9185 (MERF, holotypus). Thallus corticolous, pendulous, to 12.5 cm long, tufted from holdfast, densely branched, branching mainly dichotomous, with small cilia in apices; laciniae ochre-colored, subshiny, flat to canaliculate, more or less filamentous, 0.6-0.8 mm broad; pseudocyphellae lateral or laminal, ellipsoid, raised on small tubercles, few sorediate; cortical tissue paraplectenchymatous, 6-8 jim thick, of thick-walled hyphae, becoming disrupted by pseudocyphellae, peripheral chondroid tissue sometimes forming continuous upper and lower layers, 34-40 /zm thick, medulla dense. Pycnidia not seen. Photobiont protococcoid, cells subglobose to globose, 5.5-9.1 gcm diam. Apothecia not seen. Chemistry (TLC). Salazinic acid. Distribution and habitat. -Ramalina andina is known from subalpine altitudes (2,200-2,500 m) on the mountains of eastern and central Merida state but may have been overlooked elsewhere. It is found in very moist rain forests, growing on trees and shrubs. Ramalina andina is anatomically and chemically similar to R. pacifica Asah. (Stevens 1987). Both species are characterized by cortical tissue disrupted by pseudocyphellae, and salazinic acid as a chemical 0007-2745/94/26-33$0.95/0 This content downloaded from 157.55.39.221 on Sun, 06 Nov 2016 04:59:28 UTC All use subject to http://about.jstor.org/terms 1994] MARCANO & MORALES: RAMALINA SPP. NOV. FROM VENEZUELA 27

Lead in roadside soils of Merida City, Venezuela

The lead content of soil along the roadside in Mérida City was investigated. Where motor vehicle traffic volume was < 5000 motor vehicles per day, almost no lead accumulation was observed in the surface soil (0–2 cm), but where the motor vehicle traffic volume was > 10000 motor vehicles per day, levels of lead increased by a factor of up to ∼ 18. The soil lead content decreased with distance from the edge of the roadside and with depth of sampling.