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Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The continental shelf north of Central Venezuela is partially or completely structurally controlled by major right lateral strike slip active faults (e.g. San Sebastián fault), comprising three physiographic provinces, from west to east: The Golfo Triste Platform, the Choroní Basin and the La Guaira Platform. The two mentioned platforms are of erosional type while the Choroní basin is a deep depression, which is incised by submarine canyons. These canyons seem to be related to turbidity currents with greater flows during the Pleistocene wetter periods. Following several authors, these submarine canyons are partially or completely structurally controlled by major structures present in the north-central coastal range of Venezuela. Five major regional unconformities and/or seismostratigraphic limits have been identified. We propose to correlate the most recent to MIS 2 (Last Glacial Maximum ~ 20 ka) lowstand. The chronological significance of the deepest detected major uncomformity (strong erosion) is tentatively attributed to MIS 6 (~130 ka) lowstand. Based on the present-day position of the later one, we propose an estimation of ~1.2 mm.y-1 of the mean subsidence rate in the La Guaira Shelf, considering that the obtained value may locally represent a minor vertical component of the dominantly horizontal displacement along the San Sebastián Fault. The San Sebastián fault shows a linear deformation in the eastern profiles. In contrast to the west, we observe in some profiles an intense deformation zone. [ABSTRACT FROM AUTHOR]

This study analyses the effect of the modifiable areal unit problem (MAUP) comparing mortality data of a specific rare disease (Huntington) in three levels of spatial aggregation in Spain. The objective is to compare mortality indicators and cartographic visualisations in order to soundly advise on the optimal aggregation level according to population, covered area, and number of cases. We designed an adjacency ratio to observe the effect of neighbourhood relationships among three geographic units: province; district (comarca); municipality. For each level of aggregation, we performed epidemiological indicators of mortality as well as local indicators of spatial association. Maps were plotted with user-defined intervals to compare visual and statistical differences. MAUP-related effects are particularly noticeable in relatively infrequent events such as rare diseases. We found that district displayed the highest indicator for stability in the adjacency ratio and showed optimal characteristics for spatial resolution and the amount of information revealed through plotting. This helps in the choice of the working scale that can be used with other diseases or the levels of aggregation as a first step for more advanced epidemiological analyses. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A produção primária em pastagens naturais no Rio Grande do Sul (RS) está diretamente relacionada às condições edafoclimáticas e de manejo a que esta pastagem está sendo submetida. O objetivo deste trabalho foi c aracteriza r e analisar possíveis relações não aparentes, através da meta-análise, utilizando dados de produção de forragem oriundos de nove experimentos, realizados entre 2000 e 2012, em pastagens natura is no RS. A base de dados foi composta por 208 observações, procedentes de experimentos realizados em três diferentes regiões fisiográficas do RS. As variáveis utilizadas foram massa de forragem (MF), oferta de forragem real (OFR) e taxa de acúmulo diária (TAD). Os dados foram transformados vetorialmente pela amplitude e submetidos às análises multivariadas de agrupamento, ordenação e aleatorização utilizando a distância Euclidiana como medida de semelhança. A análise de agrupamento formou três grupos de unidades amostrais. A MF e OFR foram as variáveis de maior correlação (r= 0,85, para ambas) com o eixo I da o rdenação d as unidade s am ostrais, o qual expl icou a ma ior variação dos re sultados (49,59%). As MF foram diferentes entre os três grupos (3469, 1743 e 1403 kg ha-1 respectivamente para os grupos 1, 2 e 3). A TAD dos grupos 1 e 3 foi semelhante (12,4 kg ha1dia--1.) (P= 0,49) e maior em relação ao grupo 2. A OFR dos grupos 2 e 3 foi semelhante (13,4 kg MS por 100 kg PV) e menor em relação ao grupo 1 (30,8 kg MS por 100 kg PV). A análise evidenciou para os grupos formados distintas MF e TAD podem resultar em semelhantes OFR. Primary production in natural pastures in Rio Grande do Sul (RS) is directly related to environmental conditions and management of the pasture that is being submitted. The aim of this study was to characterize and analyze possible relationships not apparent, through meta-analysis, using data from forage production from nine experiments, conducted between 2000 and 2012 in rangelands in RS. The database consisted of 208 observations, originating f rom experiments per formed on three di ff erent physiographic regio ns of the state. The variables used were herbage mass (MF), forage allowance (OFR) and forage accumulate rate (TAD). The data were processed by vectorial amplitude and subjected to multivariate analysis of clusters, randomization and ordination using the Euclidean distance as similarity measure. The MF and OFR variables were similar and higher correlation (r = 0.85) with axis I of the ordination of sample units, which explained most of the variation in results (49.59%). MF were different among the three groups (3469, 1743 and 1403 kg ha--1. respectively for groups 1, 2 and 3). TAD of groups 1 and 3 was similar (12.4 kg ha-1.day- 1) (P= 0.49) and higher than in group 2. OFR in groups 2 and 3 was similar (13.4 kg DM per 100 kg LW) and lower than in group 1 (30.8 kg DM per 100 kg LW). The analysis revealed distinct groups formed for the MF and TAD may result in similar OFR. [ABSTRACT FROM AUTHOR]

El artículo habla de Tzintzuntzan en el estado de Michoacán, México. Hay cuatro unidades fisiográficas que integran el estado con el resto del país. Éstas cuatro incluyen el Eje Volcánico Transversal, la Sierra Madre del Sur, la Altiplanicie Mexicana y la Depresión del Rió Balsas. Estudios arqueológicos, etnográficos e históricos han descubierto una diversidad importante en esta región del país. Dentro del área, hay siete sitios arqueológicos abiertos al público, uno que es Tzintzuntzan, el centro del reino tarasco.