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1.
A 17-year period during which interaction occurred between the Chumash and Spanish colonizers is the focus of the study. Significant variation in subsistence and interactive patterns during this period is identified. The baptismal rite that marked the transition from native villager to mission Indian is interpreted in relation to the environmental and subsistence realities faced by both the Chumash and Spanish.  相似文献   

2.
At least 150 plant species were used for food, medicine, material culture, and religious practices by the Chumash Indians of southern California. A great deal of traditional Chumash plant knowledge survived into the present century, despite massive deculturation. The most significant source of information on Chumash ethnobotany is the extensive, unpublished field notes of John P. Harrington, based on interviews conducted from 1912 into the 1950s. Several hundred voucher specimens collected by some of Harrington’s consultants have also been preserved, along with the original notes, at the Smithsonian Institution. Data are presented here on knowledge and uses of plants in this important California Indian culture, as reconstructed from the Harrington material. Changes in plant knowledge resulting from Euro-American contact are also discussed.  相似文献   

3.
San Luis de Apalachee, one of a chain of Roman Catholic missions established in Spanish Florida (modern states of Georgia and Florida) in the sixteenth and seventeenth centuries, was the principal center of missionization of native populations in the Florida panhandle. Paleoethnobotanical remains yield evidence of production of various kinds of crops at the site, typical of nearly all mission period sites in the area. Stable isotope (carbon and nitrogen) analysis and dental caries evidence suggest that maize was not as important in the diet at San Luis as in other contemporary settings in the region. Ethnohistorical research indicates a heavier reliance on meat consumption compared to other mission settings. This study examines dental microwear of occlusal surfaces of maxillary molars from San Luis and five other Native American mission period sites in Spanish Florida. Epoxy casts of molar crushing facets were photographed under 500x magnification, using a scanning electron microscope. Photomicrographs were digitized using Microware 4.02 (Ungar [2002a]) and statistically evaluated using one-way ANOVA and post hoc Tukey's multiple comparisons tests. These analyses reveal that the frequency of pitting on the San Luis molars is significantly greater than for other mission period sites. Consistent with bioarchaeological, historical, and archaeological documentation, these findings suggest that diets were different in the San Luis natives in comparison with the other native populations in Spanish Florida. Various dietary factors likely came into play, resulting in these differences, and may have included significantly greater meat consumption at San Luis.  相似文献   

4.
Persistence and stability of lotic invertebrate communities in New Zealand   总被引:4,自引:0,他引:4  
1. Persistence and stability of lotic invertebrate communities were determined at an annual time scale over a 9‐year period (1990–98) at 26 river sites over the northern half of New Zealand. In addition, a number of water quality variables were measured monthly and flow information collected continuously over the same period at each site. 2. The aim of the study was to describe the levels of interannual variability in invertebrate communities, and relate community changes to variability in environmental conditions. The consequences of this temporal variability for the sensitivity of predictive models were also investigated. 3. Levels of change in environmental conditions varied significantly between years, but were relatively similar across sites. In contrast, community persistence (similarity between years in species assemblage composition), and stability (similarity between years with respect to relative abundance of species in the community) both varied significantly between sites, but changes between years were similar. Community stability was highest at sites with relatively harsh flow conditions (high coefficient of variation, high relative size of floods), and was also greater in communities dominated by Ephemeroptera. 4. Relationships between change in environmental conditions and changes in community composition and structure were relatively weak for most individual sites. However, when average levels of change for each of the 26 sites were used, communities showed greater persistence under conditions where flow conditions remained relatively constant. Water quality changes had no significant effect on community persistence when assessed for all 26 sites combined. 5. Results from this study suggest that lotic invertebrate communities fluctuate around a relatively stable state, at least over a 9‐year period. However, the extent of interannual variation in community composition and structure observed, along with the relatively low degree of cluster fidelity observed within a single region, suggests that predictive models based on reference site conditions extrapolated over several years should be applied with caution in New Zealand streams.  相似文献   

5.
In a world of growing anthropogenic pressures on biodiversity, effective indicators need to be specific and sensitive to the pressures in the ecosystem concerned, yet be simple enough to be interpreted by non-experts and straightforward enough to facilitate routine monitoring. Globally, seabirds are under increasing pressure as a result of anthropogenic activities and environmental variation. Traditionally, seabird indicators have been based on abundance at breeding colonies. However, as many species do not reach sexual maturity for several years, and may not attend the colony over this time period, such indicators may fail to capture the ecological complexity of the system concerned.We constructed two indicators of the state of nine seabird species that breed along the UK coast of the North Sea: (i) abundance of seabirds at breeding colonies, and (ii) probability of seabird breeding failure. The indicators were significantly and strongly correlated with each other for eight out of nine species, but the abundance indicator typically lagged the indicator on seabird breeding failure by two to three years. We then considered a third indicator which compared kittiwake (Rissa tridactyla) breeding success to the levels expected given the underlying environmental conditions; changes in the abundance indicator also lagged this by three years. We investigate how sensitive each of these indicators was to the impacts of fishing. We found that the species which had seen the greatest increases in breeding failure rate over the study period were those species which were most sensitive to fisheries pressure.By focussing on demographic parameters, and correcting for the underlying environmental conditions, we can detect potentially important population level changes at an earlier stage than by focussing on abundance alone. These indicators are able to more accurately capture the complexity of the ecosystem concerned and can be readily interpreted by policy-makers.  相似文献   

6.
Under climate warming, plants will undergo novel selective pressures to adjust reproductive timing. Adjustment between reproductive phenology and environment is expected to be higher in arctic and alpine habitats because the growing season is considerably short. As early- and late-flowering species reproduce under very different environmental conditions, selective pressures on flowering phenology and potential effects of climate change are likely to differ between them. However, there is no agreement on the magnitude of the benefits and costs of early- vs. late-flowering species under a global warming scenario. In spite of its relevance, phenotypic selection on flowering phenology has rarely been explored in alpine plants and never in Mediterranean high mountain species, where selective pressures are very different due to the summer drought imposed over the short growth season. We hypothesized that late-flowering plants in Mediterranean mountains should present stronger selective pressures towards early onset of reproduction than early-flowering species, because less water is available in the soil as growing season progresses. We performed selection analyses on flowering onset and duration in two high mountain species of contrasting phenology. Since phenotypic selection can be highly context-dependent, we studied several populations of each species for 2 years, covering their local altitudinal ranges and their different microhabitats. Surrogates of biotic selective agents, like fruitset for pollinators and flower and fruit loss for flower and seed predators, were included in the analysis. Differences between the early- and the late-flowering species were less than expected. A consistent negative correlational selection of flowering onset and duration was found affecting plant fitness, i.e., plants that bloomed earlier flowered for longer periods improving plant fitness. Nevertheless, the late-flowering species may experience higher risks under climate warming because in extremely warm and dry years the earlier season does not bring about a longer flowering duration due to summer drought.  相似文献   

7.
Advanced watercraft were in use at historic contact among a number of the most complex hunting-gathering societies of western North America, including the Chumash and the Nootkans. Though anthropologists often relegate technological innovations to very minor roles as stimuli toward social evolution and power inequities, archaeological analyses of long-term cultural change cannot afford to ignore the many social, symbolic, and practical implications of major innovations in transportation. Analysis of the linkages between watercraft and political, ideological, and economic systems reveals a strong association between social complexity and transportation of high capacity and range among maritime peoples.  相似文献   

8.
Low back disorders (LBDs) are the most common and costly occupationally-related compensable conditions facing employers today. Over the years several biomechanical assessment models have been developed that intended to assess the load profile imposed upon the spine during lifting and, thus, intended to facilitate the control of LBD risk in the workplace. Many of these biomechanical models have evolved based upon assumptions about how the trunk musculature respond to loads imposed upon the body during lifting. However, few of these models have been able to accurately predict the co-contraction of the trunk musculature which has been shown to have a major influence on the development of spinal loads. Thus, our understanding of how the spine is loaded under realistic dynamic lifting conditions has been deficient. A biologically-assisted or EMG-assisted model has been developed in our laboratory over the past 15 years which endeavours to overcome these traditional problems. The model has been assessed in the sagittal, coronal, and torsional planes of the body. The model development and performance will be reviewed as well as the benefits for controlling occupationally-related LBDs.  相似文献   

9.
Introduction: Children under five years of age living in poor areas and with low availability of healthy food have a higher risk of undernutrition-related mortality. However, this relationship has not been well established among older adults.Objective: To analyse socioeconomic inequality trends related to undernutrition mortality in children under five years of age and adults over 60 in Colombian municipalities during 2003-2009 and 2010-2016.Materials and methods: We conducted an ecological study of trends between 2003 and 2016. The study population consisted of children under five years of age and adults over 60 residing in the Colombian municipalities during the study period. We estimated smoothed and standardized mortality rates by fitting a hierarchical Bayesian model and explored their relationship with five socioeconomic area-level variables.Results: In most of the municipalities, undernutrition-related mortality was three times higher in older adults compared to children. Moreover, the difference in the risk of undernutrition-related mortality between municipalities showed a marked reduction. Finally, the poor and less developed municipalities had higher rates of undernutrition-related mortality in children; conversely, wealthier territories had higher rates in older adults.Conclusions: Although in most of the municipalities the mortality rates due to undernutrition in children under five and older adults have decreased, their socioeconomic conditions influence in different ways the risk of mortality for these two populations so there is the need to develop age-specific strategies to close social gaps considering the structural conditions of the areas.  相似文献   

10.
Arctic breeding shorebirds travel thousands of kilometres between their wintering and breeding grounds, yet the period over which they arrive and begin to initiate nests spans only several weeks. We investigated the role of local conditions such as weather, snow cover and predator abundance on the timing of arrival and breeding for shorebirds at four sites in the eastern Canadian arctic. Over 11 years, we monitored the arrival of 12 species and found 821 nests. Weather was highly variable over the course of this study, and the date of 50% snow cover varied by up to three weeks between years. In contrast, timing of arrival varied by one week or less at our sites, and was not well predicted by local conditions such as temperature, wind or snow melt. Timing of breeding was related to the date of 50% snow melt, with later snow melt resulting in delayed breeding. Higher predator abundance resulted in earlier nesting than would be predicted by snow cover alone. We hypothesise that when predation risk is high, the value of potential re‐nesting exceeds the energetic risks of early breeding. Synchrony of breeding was significantly higher in late breeding years suggesting a relatively fixed date for the termination of nest initiation, after which nesting is no longer profitable.  相似文献   

11.
How Spaniards Became Chumash and other Tales of Ethnogenesis   总被引:1,自引:1,他引:0  
In the 1970s, a network of families from Santa Barbara, California, asserted local indigenous identities as "Chumash." However, we demonstrate that these families have quite different social histories than either they or supportive scholars claim. Rather than dismissing these neo-Chumash as anomalous "fakes," we place their claims to Chumash identity within their particular family social histories. We show that cultural identities in these family lines have changed a number of times over the past four centuries. These changes exhibit a range that is often not expected and render the emergence of neo-Chumash more comprehendible. The social history as a whole illustrates the ease and frequency with which cultural identities change and the contexts that foster change. In light of these data, scholars should question their ability to essentialize identity.  相似文献   

12.
Estimating the development of collateral circulation in peripheral vascular diseases is simplified by the use of an easy test-which can be done in an office-in which reactive hyperemia is observed in an extremity as it is gradually lowered after a period of elevation. The lower limits of filling pressures necessary to allow spontaneous healing of necrotic lesions under the conditions described seem to be in the range 35 cm. above the heart. Similarly the lower limit for the successful performance of amputations at the level of the forefoot or toes seems to be about 45 cm. As a result of over a thousand observations in a period of over five years, it is believed that the test provides in a few minutes a visual and reproducible picture of the filling pressures in the distal portions of the extremity which is useful in the determination of prognosis and the selection of treatment of gangrenous lesions of the foot.  相似文献   

13.
Patients with chronic kidney disease (CKD) have a substantially increased risk of cardiovascular disease (CVD) compared with the general population. The high prevalence of established traditional risk factors for atherosclerosis (diabetes, hypertension, dyslipidemia) in these patients undoubtedly contributes to the accelerated rate of vascular disease. In addition, several hypotheses have emerged to explain the high prevalence of CVD in patients with chronic renal failure. Growing evidence has been gathered over the last 15 years regarding the role of uremia-related risk factors such as inflammation and oxidant stress in the pathogenesis of atherosclerosis in subjects with renal failure. This paper will review current knowledge regarding the potential role of these non-traditional or uremia-related risk factors for atherosclerosis with special emphasis on prevalence, cardiac risk, and management in patients with CKD.  相似文献   

14.
Exposure to space radiation has long been acknowledged as a potential showstopper for long-duration manned interplanetary missions. In an effort to gain more information on space radiation risk and to develop countermeasures, NASA initiated several years ago a Space Radiation Health Program, which is currently supporting biological experiments performed at the Brookhaven National Laboratory. Accelerator-based radiobiology research in the field of space radiation research is also under way in Russia and Japan. The European Space Agency (ESA) supports research in the field in three main directions: spaceflight experiments on the International Space Station; modeling and simulations of the space radiation environment and transport; and, recently, ground-based radiobiology experiments exploiting the high-energy SIS18 synchrotron at GSI in Germany (IBER program). Several experiments are currently under way within IBER, and so far, beams of C and Fe-ions at energies between 11 and 1,000 MeV/n have been used in cell and tissue targets.  相似文献   

15.
Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so‐called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure Pp that is highly correlated with the turgor pressure. Real‐time recording of Pp values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic‐based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the Pp values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non‐invasive turgor pressure sensor system for elucidating the dynamics of short‐ and long‐distance water transport in higher plants.  相似文献   

16.
Estimating the development of collateral circulation in peripheral vascular diseases is simplified by the use of an easy test—which can be done in an office—in which reactive hyperemia is observed in an extremity as it is gradually lowered after a period of elevation.The lower limits of filling pressures necessary to allow spontaneous healing of necrotic lesions under the conditions described seem to be in the range 35 cm. above the heart. Similarly the lower limit for the successful performance of amputations at the level of the forefoot or toes seems to be about 45 cm.As a result of over a thousand observations in a period of over five years, it is believed that the test provides in a few minutes a visual and reproducible picture of the filling pressures in the distal portions of the extremity which is useful in the determination of prognosis and the selection of treatment of gangrenous lesions of the foot.  相似文献   

17.
刘珍环  张国杰  付凤杰 《生态学报》2020,40(10):3295-3302
城市化对景观的结构和功能造成极大干扰,城市景观变化引起的生态风险受到城市生态建设的关注,但景观生态风险评价技术体系尚待深化,以促进风险防范决策。研究选取植被碳固定、土壤保持、水源涵养与提供和栖息地提供等景观服务改进景观脆弱度的评价方法,以广州市为案例研究区,评价了1990—2015年广州市城市景观生态风险及其时空变化特征。研究结果表明:(1)基于景观格局与服务的景观生态风险评价能够有效地评估城市景观生态风险的空间分布,但评价需要关注结果验证和辅助情景分析,方可为景观生态风险的预警和预测提供科学依据。(2)1990—2015年广州市的景观干扰度先增加后降低,2000年是景观干扰度变化的转折点;25年间,景观脆弱度不断增加,中脆弱度和高脆弱度比例之和维持在60%以上;2000年是景观生态风险的转折点,1990—2000年景观生态风险趋于增大,2000—2015年景观生态风险趋向降低;景观干扰度、脆弱度和生态风险在空间上呈现南部高于北部,西部高于东部的分布特征。(3)近25年,广州市景观生态风险与景观变化具有较好的空间一致性。维持低风险的比例为40.74%,基本都分布在北部山区,而维持高风险...  相似文献   

18.
This study analyses patterns of sociopolitical incorporation among immigrant entrepreneurs in Ontario who entered Canada under the auspices of the federal Business Immigration Program [BIP] between 1984 and 1994. The analysis focuses specifically on issues of transnationalism, adaptation to mainstream social and political institutions, and citizenship. In-depth interviews of a sample of BIP entrepreneurs reveal that, over a period of eight to eighteen years, respondents generally achieved a high level of political awareness, maintained weak transnational ties, and naturalized at an extraordinarily high rate. In the process of sociopolitical integration, respondents relied primarily on human forms of capital, especially English language proficiency and business skills, rather than on the social capital that inheres in ethnic communities and networks.  相似文献   

19.
Mexico has a wealth of historical information regarding extreme climate, famine and disease in the colonial period and even in prehispanic times. The recent development of long tree-ring chronologies throughout Mexico now allows comparison between records of past climate and socioeconomic conditions. North American tree-ring data indicate that, for the 3 consecutive years from 1785 to 1787, a major drought occurred across Mexico and the central United States with the most intense conditions extending north from Zacatecas into Texas. This period included the infamous ‘El Año del Hambre,’ one of greatest famines in Mexican history. The tree-ring data are also correlated with maize yield in central Mexico and with the value of Church tithes normally paid with agricultural goods. Drought and crop failure caused the dramatic inflation of crop value and Church tithes in 1786–1787 when tree-ring data indicate that the 1780s drought was most extreme.  相似文献   

20.
The metabolic and cardiovascular complications associated with in-utero undernutrition have been identified during the past 10 years. Reduced fetal growth is independently associated with an increased risk of development of cardiovascular diseases, the insulin-resistance syndrome or one of its components (i.e., hypertension, dyslipidaemia, impaired glucose tolerance and type 2 diabetes). Insulin resistance appears to be a key component underlying these metabolic complications. Although the mechanism remains unclear, several pieces of evidence support an active role of adipose tissue in the emergence of insulin resistance (an abnormal growth pattern and repartition, hypersensitivity to catecholamines, regulation of leptin and adiponectin secretion and modulation of peroxisome proliferator-activated receptor gamma). Among individuals born SGA, those who are more at risk of gaining excess adiposity are those who are thin at birth following a period of fetal growth restriction. This period of undernutrition is followed by a neonatal period of catch-up growth and renutrition. This pattern induces important modifications in adipose tissue, with long-term consequences, among which is a high risk of early development of insulin resistance. Not all individuals born SGA will show such modifications in adipose tissue, meaning that not all of those born SGA are at risk of insulin resistance and diabetes. From a broader point of view, several hypotheses have been proposed over the past 10 years to explain this unexpected association between being born SGA and the later development of disease. Each of them points to a detrimental fetal environment, to a genetic susceptibility or to interactions between these two components playing a critical role in this context. Although not confirmed, the hypothesis suggesting that this association could be the consequence of genetic/environmental interactions remains the most attractive.  相似文献   

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