拉丁美洲及加勒比地区的城市运输:厄瓜多尔昆卡的实例

在拉丁美洲及加勒比地区,有75%的人口居住在城市中,因此无论从经济角度还是从社会效益及可持续环境方面来看,城市交通服务都是至关重要的.巴西的库里蒂巴市,启用了一种高效、经济、有效利用土地的公共交通系统.并由美国国际发展银行出资,将库里蒂巴的综合方法尽力推广到该地区的其他大、中城市.在厄瓜多尔的昆卡市,专业的技术协作已经给当地的交通服务领域带来了许多变化.     

Human K10 epithelial keratin is the most abundant protein in airborne dust of both occupied and unoccupied school rooms

Previously it was demonstrated that the levels of large particles (>2 micron) and associated bacterial cell envelope markers increase greatly on occupation in schools; it was hypothesized that the source of both was shed human skin. In the current work to test this hypothesis, room air cleaners were used to collect airborne dust (>50-100 mg) from occupied and unoccupied school rooms which was then subjected to proteomic analysis. Proteins were extracted from the dust and separated using two dimensional gel electrophoresis (2D GE). In situ digestion of protein spots with trypsin released peptides, which were subsequently analyzed by matrix assisted laser desorption/deionization, time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry (MALDI-TOF-MS-MS). In Coomassie blue stained gels, a single spot generally dominated the 2D gels; this protein was identified by tandem mass spectrometry as K10 epithelial keratin. The results experimentally confirm previous anecdotal reports that human skin is readily shed into air and suggest that increased levels of microbial markers and large particles observed in occupied rooms are also derived from skin.     

Recovery of benthic invertebrate communities from acidification in Killarney Park lakes

Using a reference-condition comparison, recovery of benthic invertebrate communities from acidification was assessed in three lakes in Killarney Wilderness Park approximately 40–60 km from the massive metal smelters in Sudbury, Canada. Test site analyses (TSAs) were used to compare the park lakes to 20 reference lakes near Dorset Ontario, 200 km to the east. An extension of a previous survey (1997–2001) of two sensitive mayfly species (Stenonema femoratum and Stenacron interpunctatum) was conducted in one of the lakes. TSA results indicate that the three Killarney lakes remain significantly different from reference condition due primarily to higher abundances of a few acid-tolerant families and the presence of some less abundant sensitive families. Colonization rates differ greatly between the two mayfly species presumably because of competition for available habitat. Overall, this study suggests that early colonizers will gain an advantage to out-compete subsequent arrivals, and these competitive interactions will delay the return of communities to reference condition.     

Methods to estimate solar radiation dosimetry in coral reefs using remote sensed, modeled, and in situ data

Solar irradiance has been increasingly recognized as an important determinant of bleaching in coral reefs, but measurements of solar radiation exposure within coral reefs have been relatively limited. Solar radiation dosimetry within multiple coral reef areas of South Florida was assessed using remote sensed, modeled, and measured values during a minor bleaching event during August 2005. Coral reefs in the Dry Tortugas and Upper Keys had similar diffuse downwelling attenuation coefficients (Kd, m(-1)), whereas Kd values were significantly greater in the Middle and Lower Keys. Mean 1% attenuation depths varied by reef region for ultraviolet B (UVB; 9.7 to 20 m), ultraviolet A (UVA; 22 to 40 m) and visible (27 to 43 m) solar radiation. Solar irradiances determined from remote sensed data were significantly correlated with measured values, but were generally overestimated at the depth of corals. Solar irradiances modeled using an atmospheric radiative transfer model parameterized with site specific approximations of cloud cover showed close agreement with measured values. Estimated daily doses (W h/m(2)) of UVB (0.01-19), UVA (2-360) and visible (29-1,653) solar radiation varied with coral depth (2 to 24 m) and meteorological conditions. These results indicate large variation in solar radiation dosimetry within coral reefs that may be estimated with reasonable accuracy using regional Kd measurements and radiative transfer modeling.     

Learning through EC directive based SEA in spatial planning? Evidence from the Brunswick Region in Germany

This paper presents results of an international comparative research project, funded by the UK Economic and Social Research Council (ESRC) and the Academy for Sustainable Communities (ASC) on the ‘learning potential of appraisal (strategic environmental assessment — SEA) in spatial planning’. In this context, aspects of ‘single-loop’ and ‘double-loop’ learning, as well as of individual, organisational and social learning are discussed for emerging post-EC Directive German practice in the planning region (Zweckverband) of Brunswick (Braunschweig), focusing on four spatial plan SEAs from various administrative levels in the region. It is found that whilst SEA is able to lead to plan SEA specific knowledge acquisition, comprehension, application and analysis (‘single-loop learning’), it is currently resulting only occasionally in wider synthesis and evaluation (‘double-loop learning’). Furthermore, whilst there is evidence that individual and occasionally organisational learning may be enhanced through SEA, most notably in small municipalities, social learning appears to be happening only sporadically.     

Contributions of Private Landowners to the Conservation of the Gopher Tortoise (<Emphasis Type="Italic">Gopherus polyphemus</Emphasis>)

Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned land is extensive. The range of the gopher tortoise (Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584 individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%). Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production. In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents (57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions should be relevant to the conservation of other rare species on private lands in other regions.     

Hexavalent chromium reduction kinetics in rodent stomach contents

Reduction of hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)) in the stomach prior to absorption is a well-recognized detoxification process thought to limit the toxicity of ingested Cr(VI). However, administration of high concentrations of Cr(VI) in drinking water cause mouse small intestinal tumors, and quantitative measures of Cr(VI) reduction rate and capacity for rodent stomach contents are needed for interspecies extrapolation using physiologically-based toxicokinetic (PBTK) models. Ex vivo studies using stomach contents of rats and mice were conducted to quantify Cr(VI) reduction rate and capacity for loading rates (1-400 mg Cr(VI) L⁻¹ stomach contents) in the range of recent bioassays. Cr(VI) reduction was measured with speciated isotope dilution mass spectrometry to quantify dynamic Cr(VI) and Cr(III) concentrations in stomach contents at select time points over 1 h. Cr(VI) reduction followed mixed second-order kinetics, dependent upon concentrations of both Cr(VI) and the native reducing agents. Approximately 16 mg Cr(VI)-equivalents of reducing capacity per L of fed stomach contents (containing gastric secretions, saliva, water and food) was found for both species. The second-order rate constants were 0.2 and 0.3 L mg⁻¹ h⁻¹ for mice and rats, respectively. These findings support that, at the doses that caused cancer in the mouse small intestine (?20 mg Cr(VI) L⁻¹ in drinking water), the reducing capacity of stomach contents was likely exceeded. Thus, for extrapolation of target tissue dose in risk assessment, PBTK models are necessary to account for competing kinetic rates including second order capacity-limited reduction of Cr(VI) to Cr(III).     

Evaluating Flow Diversion Impacts to Groundwater‐Dependent Riparian Vegetation with Flow Alteration and Groundwater Model Analysis

An approach for assessing the potential ecologic response of groundwater‐dependent riparian vegetation to flow alteration is developed, focusing on change to groundwater. Groundwater requirements for riparian vegetation are reviewed in conjunction with flow alteration statistics. Where flow alteration coincides with groundwater‐related vegetation sensitivities, scenarios are developed for groundwater simulation. Groundwater depths and recession rates in the riparian zone are simulated for baseline and altered stream hydrographs, with changes to river stage and width represented with a transient, flow‐dependent boundary condition. Potential flow diversion from the Upper Gila River in New Mexico is examined. Statistical flow alteration analysis, applying prospective diversions to a 76‐year record of daily flow, shows that flows in the winter‐spring months and within the high‐pulse to small flood range are subject to greatest potential change. Groundwater simulation scenarios are developed for these flow conditions in representative dry, near‐average, and wet years. Differences in groundwater elevations, generally less than 0.25 m during the flow alteration period, dissipate rapidly following cessation of diversion. Relating groundwater depth, recession rates and range of fluctuations to riparian vegetation needs, we find adverse ecological response is not expected from groundwater impacts for the flow alteration examined.     

Controlling Air Toxics Emissions From Remediation by Monitoring of Surrogate Parameters

Particulate matter (dust) from remediation and demolition sites may pose a potential risk to the nearby public due to the presence of various contaminants. Unfortunately, there are no good options for real‐time monitoring of metals, polychlorinated biphenyls, etc. in wind‐blown dust. A three‐tiered approach involving a combination of real‐time monitoring and off‐site analysis that has proved successful is described in this article. PM₁₀ is used as a surrogate parameter for metals and other nonvolatile pollutants, and real‐time monitoring is used to guide dust control measures. If dust emissions are controlled, air emissions of metals and other nonvolatile pollutants also are controlled. © 2014 Wiley Periodicals, Inc.     

Reproducibility of the Pulmonary Function Response of Older Men and Women to a 2-Hour Ozone Exposure.

To test the reproducibility of the pulmonary function response to ozone exposure in older individuals, eight men and eight women, average age 62.8 years, participated in three 2-hour exposures to 0.45 ppm ozone at 23.3 C and 62.5 percent relative humidity. The first and second exposures were separated by an average time of 17.2 days, and 27.3 days separated the second and third exposures. Subjects alternated riding a bicycle ergometer for 20 minutes at an average minute ventilation of 26 liters BTPS (body temperature pressure, saturated), with 20-minute rest periods. Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV-1), and forced expiratory flow between 25 and 75% of FVC (FEF 25- 75%) were measured pre and post exposure. The reproducibility of individual pre-post changes were assessed by calculation of the best linear fit and correlation coefficients between exposures. For FVC and FEV-1, the slopes were significantly different from 1, and correlation coefficients not significantly different from zero, implying that older individuals may not respond consistently to similar ozone exposures.