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Techniques of spatial statistics and GIS are applied to socio-economic, demographic and HIV sentinel data to characterize the geographical distribution of HIV prevalence in Zambia and to estimate current prevalence rates. Maps of the 4?years under study (i.e. 1994, 1998, 2002 and 2004) reveal a spatial variation in HIV prevalence with urban and provincial districts having higher prevalence than rural areas. However, there was an overall trend of decrease in HIV prevalence across the country. The year 2004 exhibited the most reduction, coinciding with protective sexual behavior campaigns operating in the country. Risk factors for HIV prevalence included literacy rates, unemployment, poverty and urban residency. Analysis of regression residual maps indicated high spatial autocorrelation: Moran’s I value was 0.28 (z?=?4.12 and p?<?0.000) and a highly significant Robust LM (lag; p?<?0.00000) suggestive of contagious and hierarchic spatial diffusion processes. High HIV prevalence rates among interdependent districts and locational similarity patterns suggest that HIV control programs in the country would require an integrated approach combining HIV prevention messages as well as an understanding of social and cultural interactions between interdependent districts that produce behavioral diffusion of HIV prevalence rates. 相似文献
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Marta Rutz López Francisco J. Núñez Cornú Carlos Suárez Plascencia 《Geofísica Internacional》2013,52(1):59-72
The coast in the state of Jalisco and south of Nayarit is located within a region of high seismic potential, increasing population, and tourism development. This motivated Civil Defense authorities of Jalisco and the Universidad de Guadalajara to launch in the year 2000 the assessment of the seismic risk of the region. This work focuses in the seismicity study of the area of Bahía de Banderas and northern coast of Jalisco, which is actually a seismic gap. We perform an analysis of available seismograms to characterize active crustal structures, their relationship to surface morphology, and possible extent of these structures into the bay shallow parts. The data consist of waveforms recorded during 2003 when the seismograph network spanned the region. Our method is based on the identification of seismic clusters or families using cross-correlation of waveforms, earthquake relocation and modeling of fault planes. From an initial data set of 404 located earthquakes, 96 earthquakes with ML < 3.6 are related to 17 potentially active continental structures. We present fault plane model for 11 structures. A subgroup of 7 structures is aligned parallel to the Middle America Trench, as a possible consequence of oblique subduction. The foci of the earthquakes were grouped into clusters corresponding to fault dimensions of hundred of meters, may be considered as asperities or barriers in tectonic structures with lengths between 10 and 30 km. These structures could generate shallow earthquakes with magnitudes between 5.0 and 6.0 and represent an additional seismic threat to the region. 相似文献
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Vyacheslav M. Zobin Imelda Plascencia Gabriel Reyes Carlos Navarro 《Journal of Volcanology and Geothermal Research》2009,179(1-2):157-167
The general characteristics of seismic signals produced by pyroclastic flows (generated by either the collapse of a lava dome or an eruptive column) and lahars at Volcán de Colima, México are discussed. The paper concentrates on the 2004–2006 activity associated with and following the extrusion of andesitic block-lava in October–November 2004. It is shown that the duration of the broad-band seismic records of pyroclastic flows lasts a few minutes while the duration of seismic records of lahars continues for tens of minutes or hours. The spectra of seismic records produced by pyroclastic flows are characterized by lower peak frequencies (around 3–4 Hz) than for lahars (around 6–8 Hz). This difference in the frequency content together with the difference in the duration of seismic signals allows early diagnostic of the events in real time. 相似文献
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