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631.
We questioned the different interpretations of ecological sexual segregation from a novel perspective, i.e., by carrying out
diverse temporal and spatial scale analyses within a long-term study (1984–2003). Thus we combined spatial (small/large) and
temporal (small/large) scale analyses to identify the factors generating sexual segregation in fallow deer in San Rossore,
Italy. The study site was divided into an eastern sector characterized by human disturbance (DS) and a western undisturbed
sector (US). According to census data, human presence increased in DS from 1984, and while females gradually abandoned it,
males remained—thus supporting the predation risk hypothesis (large spatial and temporal scale)—and actually increased their
presence in DS, where they seemingly benefited from a lower female density. This supported the indirect competition hypothesis.
The analysis of data on a large temporal and small spatial scale confirmed that intersexual competition, in particular for
grass, was higher in a crowded pasture in US. Observations by means of radio-telemetry of 23 adult females and 25 adult males
(1997–2001, reduced temporal and large spatial scale) showed that large scale segregation was relevant during the day and
disappeared at night, when disturbance was absent and also the females reached DS. This also supported the predation risk
hypothesis. Moreover, sexes showed different habitat choices inside DS at night, thus supporting the forage selection hypothesis
(small spatial and temporal scale). In conclusion, failure to address the whole set of combinations of spatial and temporal
scale analyses would have led to monocausal explanations of ecological sexual segregation. 相似文献
632.
Correia Felipo Obed Almeida Tarcísio Silva Garcia Rui Lorenzo Queiroz Antônio Fernando S. Smichowski Patricia da Rocha Gisele Olímpio Araujo Rennan Geovanny O. 《Environmental science and pollution research international》2019,26(21):21416-21424
Environmental Science and Pollution Research - In this work, fast sequential determination and chemical speciation analysis of inorganic arsenic and antimony in airborne particulate matter... 相似文献
633.
Dean F. Martin Patricia M. Dooris George M. Dooris Robert J. Bova 《Journal of the American Water Resources Association》1986,22(2):283-287
ABSTRACT: High performance liquid chromatography (HPLC) has been used to identify a fraction of aqueous sediment extract from Lake Starvation, Hillsborough County, Florida, that is responsible for inhibition of hydrilla growth. The fraction was separated on a Zorbax? C18 preparative-scale column. The present study examines various lake sediment extracts and river water samples to determine the presence or absence of the inhibitor peak. The biologically active component is absent in certain rivers where hydrilla is prominent, but it is present in extracts of Lake Starvation and White Trout Lake sediments that are known to have hydrilla growth inhibiting properties. The implications of “fingerprinting” natural waters for hydrilla inhibitor through liquid chromatography are considered. 相似文献
634.
A classification system is often used to reduce the number of different ecosystem types that governmental agencies are charged with monitoring and managing. We compare the ability of several different hydrogeomorphic (HGM)—based classifications to group lakes for water chemistry/clarity. We ask: (1) Which approach to lake classification is most successful at classifying lakes for similar water chemistry/clarity? (2) Which HGM features are most strongly related to the lake classes? and, (3) Can a single classification successfully classify lakes for all of the water chemistry/clarity variables examined? We use univariate and multivariate classification and regression tree (CART and MvCART) analysis of HGM features to classify alkalinity, water color, Secchi, total nitrogen, total phosphorus, and chlorophyll a from 151 minimally disturbed lakes in Michigan USA. We developed two MvCART models overall and two CART models for each water chemistry/clarity variable, in each case comparing: local HGM characteristics alone and local HGM characteristics combined with regionalizations and landscape position. The combined CART models had the highest strength of evidence (ωi range 0.92–1.00) and maximized within class homogeneity (ICC range 36–66%) for all water chemistry/clarity variables except water color and chlorophyll a. Because the most successful single classification was on average 20% less successful in classifying other water chemistry/clarity variables, we found that no single classification captures variability for all lake responses tested. Therefore, we suggest that the most successful classification (1) is specific to individual response variables, and (2) incorporates information from multiple spatial scales (regionalization and local HGM variables). 相似文献
635.
Jarry T. Porsius Liesbeth Claassen Patricia E. Weijland 《Journal of Environmental Planning and Management》2016,59(8):1495-1512
Cases of strong local opposition to the planned introduction of new high-voltage power lines (HVPLs) have been documented in the past. During and after the planning process for a new HVPL, local residents will be informed about the siting process and its outcomes. Although it has been suggested in the literature that this communication plays an important role in residents' responses to a new HVPL, it has been rarely empirically studied. In this qualitative study, we conducted in-depth interviews with 15 residents about their experiences with the planned introduction of a new HVPL near their homes. Thematic analysis revealed that residents' experiences were centred around negative expectations of living near the new HVPL and perceived injustice of the planning process and its outcomes. Residents' perception that communication was not tailored to their information needs played a significant role in these negative experiences. Suggestions for improving communication will be discussed. 相似文献
636.
Despite their opposition to the dominant agri-food system, alternative agri-food initiatives may unwittingly reproduce central features of neoliberalism. Julie Guthman has been a particularly strong proponent of this view, arguing that food activism and neoliberalism have shaped one another dialectically in California in recent decades. This paper responds to her argument, with a view to distinguishing between what it reveals and what it may conceal about the transformative potential of alternative agri-food initiatives in North America. Drawing on primary research on a variety of community-based food initiatives in Eastern Ontario, Canada, we show how a neoliberal lens does help to illuminate some problematic characteristics of these initiatives, including assumptions about market-based solutions and focus on self-improvement at the expense of state involvement. However, this lens underestimates those aspects of community-based food initiatives that may appear commensurate with neoliberal rationalities but which also push in more progressive directions. 相似文献
637.
Nancy S. Day Marija Tadin Angela M. Christiano Patricia Lanzano Sergio Piomelli Stephen Brown 《黑龙江环境通报》2002,22(8):686-691
Prenatal diagnosis of sickle cell diseases has been available for several years, and our laboratory has performed over 1000 prenatal diagnoses. However, currently available techniques are labor-intensive and time-consuming, and thus the diagnosis is delayed, making the mother's decision difficult. We describe a rapid, high-throughput technique based on the ligation assay coupled with automated capillary fluorescence detection. This new approach allows the diagnosis of both Hgb S and Hgb C to be available in a few hours. We have utilized this technique in 30 prenatal diagnoses and found it to be in complete agreement with the standard diagnoses. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
638.
Francis J. Magilligan Patricia F. McDowell 《Journal of the American Water Resources Association》1997,33(4):867-878
ABSTRACT: Cattle grazing practices in the western United States have contributed to widespread riparian degradation resulting in unstable channel morphologies and the loss of fish habitat. Because of prolonged disturbance, numerous riparian areas on both public and private lands have been fenced to exclude cattle in order to promote vegetation establishment and riparian improvement. We selected four gravel-bedded, steep alluvial streams in eastern Oregon with cattle exclosures greater than 14 years old for an analysis of geomorphic adjustments following the removal of cattle grazing. We compare channels inside exclosures and in adjacent grazed reaches to identify the salient stream channel properties that respond to the removal of riparian stresses and to document the magnitude of these changes. Results indicate that significant changes occur, with reductions in bankfull dimensions and increases in pool area being the most common and identifiable changes. At all four sites, bankfull widths are narrower by 10 to 20 percent, and the percentage of channel area occupied by pools is higher in the exclosure by 8 to 15 percent. The increase in pool area is primarily offset by a reduction in the percent glide area. Not all of the channel properties demonstrate adjustment, indicating that perhaps 14 years is an insufficient duration for these variables to adjust. 相似文献
639.
Kevin A. Francesconi Patricia Micks Rodney A. Stockton Kurt J. Irgolic 《Chemosphere》1985,14(10):1443-1453
The major water-soluble arsenic compound in the Alaskan king crab, the Alaskan snow crab, and the Dungeness crab was identified as arsenobetaine by HPLC/ICP analysis. This technique is suitable for the identification and quantitative determination of naturally occurring organic arsenic compounds in purified and partially purified extracts from biota. 相似文献
640.
/ For regional analyses of species imperilment patterns, data on species distributions are available from the U.S. Fish and Wildlife Service and from the state heritage programs. We compared these two different databases as sources of best available information for regional analyses of patterns of aquatic species imperilment for 132 counties in the southern Appalachians and examined patterns produced from the databases. The heritage program database contained information about a greater number of imperiled species because species need not be federally listed as threatened or endangered to be included in this database. In the southern Appalachians, about half of imperiled molluscs and about one-fourth of imperiled fish were listed as threatened or endangered; much smaller proportions of other taxonomic groups were federally listed. Most threatened and endangered species appeared on both lists, but for about 40% of the species inconsistencies exist, notably a lack of recent records in the heritage program dataset. Numbers of species in each county were significantly different between the two datasets for Georgia, Tennessee, and Virginia, where the largest number of threatened and endangered species reside. Nevertheless, some counties always appeared as centers of imperilment, and the general spatial patterns of imperilment were similar. 相似文献