共查询到20条相似文献，搜索用时 31 毫秒
1.
Robert P. Clark 《Global Change & Human Health》2001,2(2):120-132
If we think of globalization as a process that has been under way for at least ten millennia, we can see the importance of biological forces in the process. The interconnectedness of biology and globalization is best captured by the concept of coevolution. By means of coevolution, a number of global life systems have emerged that incorporate human beings, a small number of plant and animal species domesticated for food and other purposes, and a rather larger set of microbial species. These latter have entered human populations as companions of our food supply (for example, influenza and smallpox) or as a consequence of other human activities that were part of globalization, such as war, trade, and long distance migration (for example, the bubonic plague and AIDS). The coevolution paradigm helps us predict the future development of epidemics, but in the case of the AIDS pandemic, now entering its third decade, the future is still unclear. 相似文献
2.
T. B. Yanovskaya V. S. Gobarenko T. P. Yegorova 《Izvestiya Physics of the Solid Earth》2016,52(1):14-28
The P-wave travel time data from the earthquakes offshore and onshore around the Black Sea are used for the tomographic reconstruction of the three-dimensional (3D) velocity distribution in the lithosphere of the region. The preliminary refinement of the foci parameters (the coordinates and origin time) has reduced the random errors in the travel-time data. The earthquake data were supplemented by the previous deep seismic sounding (DSS) data on the profiles in Crimea and offshore off the Black Sea. The dataset included more than 4000 travel times overall. In order to eliminate the crustal effect, the travel times were reduced to a surface at a depth of 35 km corresponding to the mean Moho depth in the region. The improved crustal model was used for removing the contribution of the crust from the initial data. The new tomography method, which was recently developed by one of the authors and which relies on the assumption of smoothness of the lateral velocity variations, was applied for reconstructing the velocity structure of the upper mantle beneath the Black Sea up to a depth of 95 km. The lateral velocity variation maps at different depths and the vertical velocity distributions along the meridional and sublatitudinal cross sections across the Black Sea were constructed. High velocities were revealed in the subcrustal lithosphere, and the structural difference below two subbasins—the West Black Sea (WBS) and the East Black Sea (EBS) ones—was established. It shows that the high-velocity body below the WBS is located deeper than below the EBS and is distinguished by higher velocities. Based on these results, it is concluded that the lithosphere beneath the Black Sea has a continental origin. 相似文献
3.
A scheme of water balance differentiation of a territory is proposed. The vertical and space-time structure of water balance are considered. A procedure for regional space-time analysis of water balance was developed and tested, allowing one to evaluate its different characteristics and relationships, to simulate the series of their mean annual values in points where no observations are available, and to carry out computeraided mapping of the obtained results. Electronic maps were constructed to characterize the distribution of river runoff and its surface and subsurface components over the European Russia, the correlation and conjunction between them, the distribution of annual precipitation, and the precipitation of the warm and cold periods over the territory. Statistical relationships, reflecting different aspects of space-time variations in the major water balance elements, are given. 相似文献
4.
Aeromagnetic data were analyzed to determine the Curie point depth (CPD) by power density spectral and three-dimensional inversion methods within and surrounding Death Valley in southern California. We calculated the CPD for 0.5° regions using 2D power density spectral methods and found that the CPDs varied between 8 and 17 km. However, the 0.5° region may average areas that include shallow and deep CPDs, and because of this limitation, we used the 3D inversion method to determine if this method may provide better resolution of the CPDs. The final 3D model indicates that the depth to the bottom of the magnetic susceptible bodies varies between 5 and 23 km. Even though both methods produced roughly similar results, the 3D inversion method produced a higher lateral resolution of the CPDs. The shallowest CPDs occur within the central and southern Death Valley, Panamint Valley, Coso geothermal field and the Tecopa hot springs region. Deeper (>15 km) CPDs occur over outcropping granitic and Precambrian lithologies in the Panamint Range, Grapevine Mountains, Black Mountains and the Argus Range. The shallowest CPD occurs within the central Death Valley over a possible seismically imaged magma body and slightly deeper values occur within the Panamint Valley, southern Death Valley and Tecopa Hot Springs. The shallow CPD values suggest that partially molten material may also be found in these latter regions. The CPD computed heat flow values for the region suggest that the entire area has high heat flow values (>100 mW m?2), on the other hand, locally extremely high values (>200 mW m?2) occur within the Panamint Valley, the southern and central Death Valley and Tecopa Hot Springs region. These locally high heat flow values may be related to midcrustal magma bodies; but additional geophysical experiments are needed to determine if the magma bodies exist. 相似文献
5.
A P-spline ANOVA type model in space-time disease mapping 总被引：3，自引：3，他引：0
M. D. Ugarte T. Goicoa J. Etxeberria A. F. Militino 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(6):835-845
One of the main objectives in disease mapping is the identification of temporal trends and the production of a series of smoothed maps from which spatial patterns of mortality risks can be monitored over time. When studying rare diseases, conditional autoregressive models have been commonly used for smoothing risks. In this work, a P-spline ANOVA type model is used instead. The model is anisotropic and explicitly considers different smooth terms for space, time, and space-time interaction avoiding, in addition, model identifiability problems. The mean squared error of the log-risk predictor is derived accounting for the variability associated to the estimation of the smoothing parameters. The procedure is illustrated analyzing Spanish prostate cancer mortality data in the period 1975–2008. 相似文献
6.
An incremental Knox test for the determination of the serial interval between successive cases of an infectious disease 总被引：1，自引：0，他引：1
An estimate of the interval between successive infections is essential for surveillance, control, and modeling of infectious
diseases. This paper proposes a method for determining the serial interval when the location and time of onset of illness
are known. The theoretical underpinning of this method is the intrinsically spatial nature of disease transmission. Successive
infections tend to be closer than unrelated cases of disease and, therefore, exhibit spatial clustering. An incremental Knox
type analysis of cases is introduced. Cases occurring at a range of time intervals are examined to determine the serial interval.
The significance of clustering is determined using a permutation approach under the null hypothesis of space-time independence.
The power of this method is evaluated using an individual level, spatially explicit epidemic simulation. The time increment
Knox test is robust to multiple introductions and incomplete sampling. Finally, the increment Knox statistic is used to analyze
an outbreak of dengue fever in the city of Florida, Puerto Rico during 1991. Results indicate that the likely interval between
successive cases during this outbreak is at least 18–19 days. 相似文献
7.
本文根据历史及现今地震资料研究了陕西地区５级左右地震发生的时空规律及其相关现象，从而为陕西今后的震情判断提供依据。主要结果如下：Ｍｓ≥５地震发生的平均时间间隔为５８年，４－５级地震丛的发生间隔为１０－４０年；Ｍｓ≥５地震的活动有以９为倍数的韵律特征，并有集中在７－９月发生的现象；５级左右的地震一般都分布在渭河盒地北缘断裂或秦岭山间断裂带上；４级以上地震发生前，在震中附近一定范围内小震活跃。 相似文献
8.
IntroductionSeismicprocessisextremelycomplicatedjustashasbeenprovedbytheeallhquakepredictionpractice.Thecomplexityofseismicprocessmainlydisplaystheinhomogeneityofseismicspace-timedistribution.Therearealotoffactorscausingthecomplexity,includingthemediumofseismicsource,themechanicalprocessofseismicsource,mutualeffectofgroupseismicactivity,andsoon.Studyontheseismicactivitylawstillremainsinalowlevel,especiallyintheaspectofseismicoccurrenceprocess.Manyscholarstrytostudytheseismicactivebehavioringr… 相似文献
9.
On the assimilation of total-ozone satellite data 总被引：1，自引：0，他引：1
A two-dimensional model for advection and data assimilation of total-ozone data has been developed. The Assimilation Model KNMI (AMK) is a global model describing the transport of the column amounts of ozone, by a wind field at a single pressure level, assuming that total ozone behaves as a passive tracer. In this study, ozone column amounts measured by the TIROS Operational Vertical Sounder (TOVS) instrument on the National Oceanic and Atmospheric Administration (NOAA) polar satellites and wind fields from the Meteorological Archive and Retrieval System (MARS) archives at ECMWF have been used. By means of the AMK, the incomplete space-time distribution of the TOVS measurements is filled in and global total-ozone maps at any given time can be obtained. The choice of wind field to be used for transporting column amounts of ozone is extensively discussed. It is shown that the 200-hPa wind field is the optimal single-pressure-level wind field for advecting total ozone. Assimilated ozone fields are the basic information for research on atmospheric chemistry and dynamics, but are also important for the validation of ozone measurements. 相似文献
10.
基于地震动的时空衰减规律和传播特征,采用邻近地震监测台站地震动时程对1 km×1 km尺度的网格点进行近实时插值计算,同时结合场地效应对震区地震动参数进行修正,并以2014年2月12日新疆于田MS7.3地震为例,计算震区格网内各点的地震时程,同时以8 s为时间间隔绘制出地震动峰值等值线图并将其连续播放,得到了于田MS7.3地震峰值地震动(PGV,PGA)的空间分布.结果表明,于田县东部至民丰县北部地区受场地条件影响,震区震害在软弱地基土层及浅地下水位等因素作用下对震区地震动具有明显的放大效应,预测的地震动特征与现场宏观调查结果是一致的.在当前强震台网分布不均匀的情形下,本文方法能较好地描述震区地震动特征,较客观地反映灾区的强地面运动特征. 相似文献
11.
delta波包可由高斯波束经傅里叶逆变换得到,是高斯波束在时空域的表达.它最早出现在合成理论地震图的研究中,本文将其应用于偏移领域.通过delta波包叠加表达时间域格林函数,可将高斯波束偏移由频率域转换到时间域,再结合Rayleigh积分和激励时间成像条件,本文给出了基于delta波包叠加的深度偏移算法.该偏移算法可在时间域直接计算,但因包含褶积运算,成像时将耗费大量的计算时间.针对这一问题,本文提出了将褶积简化为乘积的近似公式.近似后的偏移算法,不仅保留了高斯波束偏移的优点,而且计算效率得到显著提升.文中通过两个数值算例验证了上述结论. 相似文献
12.
Hwa-Lung Yu Alexander Kolovos George Christakos Jiu-Chiuan Chen Steve Warmerdam Boris Dev 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(5):647-572
This paper describes the spatiotemporal epistematics knowledge synthesis and graphical user interface (SEKS–GUI) framework
and its application in medical geography problems. Based on sound theoretical reasoning, the interactive software library
of SEKS–GUI explores heterogeneous (spatially non-homogeneous and temporally non-stationary) health attribute distributions
(disease incidence, mortality, human exposure, epidemic propagation etc.); expresses the health system’s dependence structure
using (ordinary and generalized) spatiotemporal covariance models; synthesizes core knowledge bases, empirical evidence and
multi-sourced system uncertainty; and generates a meaningful picture of the real-world system using space–time dependent probability
functions and associated maps of health attributes. The implementation stages of the SEKS–GUI library are described in considerable
detail using appropriate screens. The wide applicability of SEKS–GUI is demonstrated by reviewing a selection of real-world
case studies.
An erratum to this article can be found at 相似文献
13.
Robert S. White John R. Smallwood Moritz M. Fliedner † Brian Boslaugh Jenny Maresh Juergen Fruehn ‡ 《Geophysical Prospecting》2003,51(3):215-231
We demonstrate that the use of long-offset seismic data allows wide-angle reflections and diving waves to be recorded, and that these can be used in conjunction with prestack depth migrations to constrain and to image the base of the basalt flows and the underlying structure in the Faeroe-Shetland Basin. Crustal velocity models are built first by inverting the traveltimes of the recorded reflections and diving waves using ray-tracing methods. Finer details of the velocity structure can then be refined by analysis of the amplitudes and waveforms of the arrivals. We show that prestack depth migration of selected wide-angle arrivals of known origin, such as the base-basalt reflection, using the crustal velocity model, allows us to build a composite image of the structure down to the pre-rift basement. This has the advantage that the wide-angle first-arriving energy must be primary, and not from one of the many multiples or mode-converted phases that plague near-offset seismic data. This allows us to ‘tag’ these primary arrivals with confidence and then to identify the same arrivals on higher-resolution prestack migrations that include data from all offsets. Examples are drawn from the Faeroe-Shetland Basin, with a series of regional maps of the entire area showing the basalt depths and the thickness of the basalt flows and underlying sediment down to the top of the pre-rift basement. The maps show how the basalts thin to the southeast away from their presumed source west of the present Faeroe Islands, and also show the extent to which the structure of the pre-rift basement controls the considerable variations in sediment thickness between the basement and the cap formed by the overlying basalt flows. 相似文献
14.
Following the empirical evidence of a clear correlation between rainfall events and cholera resurgence that was observed in particular during the recent outbreak in Haiti, a spatially explicit model of epidemic cholera is re-examined. Specifically, we test a multivariate Poisson rainfall generator, with parameters varying in space and time, as a driver of enhanced disease transmission. The relevance of the issue relates to the key insight that predictive mathematical models may provide into the course of an ongoing cholera epidemic aiding emergency management (say, in allocating life-saving supplies or health care staff) or in evaluating alternative management strategies. Our model consists of a set of dynamical equations (SIRB-like i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals, and including a balance of Bacterial concentrations in the water reservoir) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water. These, in turn, are driven by rainfall washout of open-air defecation sites or cesspool overflows, hydrologic transport through waterways and by mobility of susceptible and infected individuals. We perform an a posteriori analysis (from the beginning of the epidemic in October 2010 until December 2011) to test the model reliability in predicting cholera cases and in testing control measures, involving vaccination and sanitation campaigns, for the ongoing epidemic. Even though predicting reliably the timing of the epidemic resurgence proves difficult due to rainfall inter-annual variability, we find that the model can reasonably quantify the total number of reported infection cases in the selected time-span. We then run a multi-seasonal prediction of the course of the epidemic until December 2015, to investigate conditions for further resurgences and endemicity of cholera in the region with a view to policies which may bring to the eradication of the disease in Haiti. The projections, although strongly depending on still uncertain epidemiological processes, show an endemic, seasonal pattern establishing in the region, which can be better forestalled by an improvement of the sanitation system only, rather than by vaccination alone. We thus conclude that hydrologic drivers and water resources management prove central to prediction, emergency management and long-term control of epidemic cholera. 相似文献
15.
16.
Michael N. Machette 《Journal of Geodynamics》2000,29(3-5)
Maps of faults (geologically defined source zones) may portray seismic hazards in a wide range of completeness depending on which types of faults are shown. Three fault terms — active, capable, and potential — are used in a variety of ways for different reasons or applications. Nevertheless, to be useful for seismic-hazards analysis, fault maps should encompass a time interval that includes several earthquake cycles. For example, if the common recurrence in an area is 20,000–50,000 years, then maps should include faults that are 50,000–100,000 years old (two to five typical earthquake cycles), thus allowing for temporal variability in slip rate and recurrence intervals. Conversely, in more active areas such as plate boundaries, maps showing faults that are <10,000 years old should include those with at least 2 to as many as 20 paleoearthquakes. For the International Lithosphere Programs’ Task Group II-2 Project on Major Active Faults of the World our maps and database will show five age categories and four slip rate categories that allow one to select differing time spans and activity rates for seismic-hazard analysis depending on tectonic regime. The maps are accompanied by a database that describes evidence for Quaternary faulting, geomorphic expression, and paleoseismic parameters (slip rate, recurrence interval and time of most recent surface faulting). These maps and databases provide an inventory of faults that would be defined as active, capable, and potentially active for seismic-hazard assessments. 相似文献
17.
Surfzone bathymetry often is resolved poorly in time because watercraft surveys cannot be performed when waves are large, and remote sensing techniques have limited vertical accuracy. However, accurate high-frequency bathymetric information at fixed locations can be obtained from altimeters that sample nearly continuously, even during storms. A method is developed to generate temporally and spatially dense maps of evolving surfzone bathymetry by updating infrequent spatially dense watercraft surveys with the bathymetric change measured by a spatially sparse array of nearly continuously sampling altimeters. The update method is applied to observations of the evolution of shore-perpendicular rip current channels (dredged in Duck, NC, 2012) and shore-parallel sandbars (observed in Duck, NC, 1994). The updated maps are compared with maps made by temporally interpolating the watercraft surveys, and with maps made by spatially interpolating the altimeter measurements at any given time. Updated maps of the surfzone rip channels and sandbars are more accurate than maps obtained by using either only watercraft surveys or only the altimeter measurements. Hourly altimeter-updated bathymetric estimates of five rip channels show rapid migration and infill events not resolved by watercraft surveys alone. For a 2-month observational record of sandbars, altimeter-updated maps every 6 h between nearly daily surveys improve the time resolution of rapid bar-migration events. 相似文献
18.
19.
N. I. Alekseevskii D. V. Magritskii P. K. Koltermann P. A. Toropov D. I. Shkol’nyi P. A. Belyakova 《Water Resources》2016,43(1):1-14
Inundatios on the Black Sea coast of Krasnodar krai between 1945 and 2013 have been analyzed. The main genetic types of inundations on the coast have been identified. The specific features and regularities of inundation wave transformation along the rivers and over time have been studied. Seasonal and maximal runoff of Black Sea rivers has been analyzed over a long-term period. Regularities in the variations of the number of inundatios and their characteristics over the coastal area have been revealed both at the annual and long-term scales. Quantitative estimates are given to the hazard and damage to the population and economic activity due to inundations in the valleys of Black Sea rivers. 相似文献
20.
A simple method for obtaining a space-time model of the main magnetic field from the high-precision satellite survey data is described. At the first stage, the CHAMP satellite data for one-day interval are expanded into the spherical harmonics with constant coefficients. This yields a set of daily mean spherical harmonic models (DMSHM) over the survey interval of a few years. At the second stage, the coefficients of this set are used as source data for expansion into the natural orthogonal components (NOC). It is shown that the terms of the NOC series decrease rapidly, and the accuracy of the space-time model of the main geomagnetic field over the time interval under discussion is not worse than the accuracy of the models obtained by traditional methods. 相似文献