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1.
Prenatal diagnosis of Sandhoff disease (infantile onset) at 16 weeks gestation has been made by detection and analysis of N-acetylglucosaminyl-oligosaccharides in amniotic fluid using high performance liquid chromatography. The elution profile for the branched chain oli-gosaccharides was identical with that obtained with neonatal and infantile Sandhoff urine. The concentration of the oligosaccharides in the fluid was 1/100th that of urine but when calculated relative to creatinine the levels were similar. No oligosaccharides were detected in normal control amniotic fluids (10 patients) at a similar gestational age. Based on the levels of the amniotic fluid oligosaccharides and the sensitivity limits of the assay, prenatal diagnosis of patients with the juvenile onset form of the disease may also be possible with this technique. 相似文献
2.
Summary This paper describes a 13-weeks, third-year course in Environmental Planning and Management developed and taught by the authors. Initiated in 1969, the course consists of a mix of lectures, seminars, workshop/laboratory sessions and field-based projects. The objectives of the course are for students: to become aware of the need for, and the complexities of, environmental management; to be able to criticise constructively work done by environmental agencies and consultants, managers and decision makers; and to learn and apply some of the methods and techniques used in environmental management.Topics covered by the current syllabus are: concepts of resource and environment; constitutional aspects; international law and the environment; Australian and Canadian environmental legislation and agencies; human manipulation of ecosystems; energy subsidies; modification of biogeochemical cycles; population dynamics and cropping; fisheries; national parks and reserves—policies in different countries; international heritage areas; environmental assessment (including impact assessment, land evaluation, land capability and land suitability assessment); and regional, integrated land-use and environmental planning and management. Techniques taught include: field surveys and interviewing; laboratory analysis of selected water quality, sediment and soil parameters including nutrient concentrations, heavy metal and pesticide residues; and for some students, applications of geographic information systems (GIS) technology following preceding GIS courses.A major problem is selecting the most appropriate mix between the social and natural sciences—appropriate, first in terms of students' heterogeneous skills and backgrounds, and second, in terms of understanding the causes of environmental problems and issues, and devising practicable solutions. 相似文献
3.
Modifying poultry diets by reducing mineral P supplementation and/or adding phytase may change the chemical composition of P in manures and affect the mobility of P in manure-amended soils. We studied the speciation of P in manures produced by broiler chickens and turkeys from either normal diets, or diets with reduced amounts of non-phytate phosphorus (NPP) and/or phytase, using a combination of chemical fractionation and synchrotron X-ray absorption near edge structure (XANES) spectroscopy. All broiler litters were rich in dicalcium phosphate (65-76%), followed by aqueous phosphate (13-18%), and phytic acid (7-20%); however, no hydroxylapatite was observed. Similarly, normal turkey manure had 77% of P as dicalcium phosphate and had no hydroxylapatite, while turkey manure from diets that had reduced NPP and phytase contained equal proportions of dicalcium phosphate (33-45%) and hydroxylapatite (35-39%). This is attributed to the higher total Ca to P ratio (>2) in modified turkey manures that resulted in transformation of more soluble (dicalcium phosphate) to less soluble P compounds (hydroxylapatite). Chemical fractionation showed that H2O-extractable P was the predominant form in broiler litter (56-77%), whereas aqueous phosphate determined with XANES was <18% indicating that H2O probably dissolved mineral forms of P (e.g., dicalcium phosphate). Results show that HCl extraction primarily removed phytic acid from broiler litters and normal turkey manure, while it removed a mixture of hydroxylapatite and phytic acid from modified turkey manures. The combination of chemical fractionation and XANES provided information about the nature of P in these manures, which may help to devise best management practices for manure use. 相似文献
4.
Derek Vollmer Maíra Ometto Bezerra Natalia Acero Martínez Octavio Rodríguez Ortiz Ivo Encomenderos Maria Clara Marques Lina Serrano-Durn Isabelle Fauconnier Raymond Yu Wang 《Ambio》2021,50(4):870
Quantitative assessments have long been used to evaluate the condition of the natural environment, providing information for standard setting, adaptive management, and monitoring. Similar approaches have been developed to measure environmental governance, however, the end result (e.g., numeric indicators) belies the subjective and normative judgments that are involved in evaluating governance. We demonstrate a framework that makes this information transparent, through an application of the Freshwater Health Index in three different river basins in Latin America. Water Governance is measured on a 0–100 scale, using data derived from perception-based surveys administered to stakeholders. Results suggest that water governance is a primary area of concern in all three places, with low overall scores (Guandu-26, Alto Mayo-38, Bogotá-43). We conclude that this approach to measuring governance at the river basin scale provides valuable information to support monitoring and decision making, and we offer suggestions on how it can be improved.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01407-8) contains supplementary material, which is available to authorized users. 相似文献
5.
Katherine B. Beem Florian M. Schwandner Taehyoung Lee Christian M. Carrico Derek Day Jenny Hand Bret Schichtel Jeffrey L. Collett Jr. 《Environmental pollution (Barking, Essex : 1987)》2010,158(3):862-872
Increases in reactive nitrogen deposition are a growing concern in the U.S. Rocky Mountain west. The Rocky Mountain Airborne Nitrogen and Sulfur (RoMANS) study was designed to improve understanding of the species and pathways that contribute to nitrogen deposition in Rocky Mountain National Park (RMNP). During two 5-week field campaigns in spring and summer of 2006, the largest contributor to reactive nitrogen deposition in RMNP was found to be wet deposition of ammonium (34% spring and summer), followed by wet deposition of nitrate (24% spring, 28% summer). The third and fourth most important reactive nitrogen deposition pathways were found to be wet deposition of organic nitrogen (17%, 12%) and dry deposition of ammonia (14%, 16%), neither of which is routinely measured by air quality/deposition networks operating in the region. Total reactive nitrogen deposition during the spring campaign was determined to be 0.45 kg ha−1 and more than doubled to 0.95 kg ha−1 during the summer campaign. 相似文献
6.
Jennifer L. Hand Rodger B. Ames Sonia M. Kreidenweis Derek E. Day William C. Malm 《Journal of the Air & Waste Management Association (1995)》2013,63(5):677-685
ABSTRACT Aerosol water content was determined from relative humidity controlled optical particle counter (ASASP-X) size distribution measurements made during the Southeastern Aerosol and Visibility Study (SEAVS) in the Great Smoky Mountains National Park during summer 1995. Since the scattering response function of the ASASP-X is sensitive to particle refractive index, a technique for calibrating the ASASP-X for any real refractive index was developed. A new iterative process was employed to calculate water mass concentration and wet refractive index as functions of relative humidity. Experimental water mass concentrations were compared to theoretically predicted values assuming only ammonium sulfate compounds were hygroscopic. These comparisons agreed within experimental uncertainty. Estimates of particle hygroscopicity using a rural aerosol model of refractive index as a function of relative humidity demonstrated no significant differences from those made with daily varying refractive index estimates. Although aerosol size parameters were affected by the assumed chemical composition, forming ratios of these parameters nearly canceled these effects. 相似文献
7.
Derek E. Day William C. Malm Sonia M. Kreidenweis 《Journal of the Air & Waste Management Association (1995)》2013,63(3):411-418
The concentration of elements Na through Pb, select ions, and organic carbon from fine (<2.5 µm) particles has been monitored at Shenandoah and Great Smoky Mountains National Parks from 1988 through 1995. The data obtained from 1988 through 1994 show that significant changes in the concentrations of many aerosol constituents occur on a seasonal basis. Particulate sulfate and organic carbon are shown to exhibit substantially higher concentrations during the summer, while sulfur dioxide and nitrate concentrations are highest during the winter. A method for estimating the degree of neutralization of particulate sulfate is given. This method uses routinely measured aerosol elemental compositions because ammonium ion, the primary neutralizing species for sulfate, is not measured on a routine basis. Application of this method to the selected data set shows that sulfate aerosol is most acidic during summer with an average molar Hs (moles of hydrogen associated with sulfur) to S (moles of sulfur) ratio of approximately 4. This suggests the average sulfate particle during the summer has a molar coon slightly more acidic than ammonium bisulfate (NH4HSO4) which has a molar hydrogen to sulfur ratio of 5. Winter Hs to S ratios, however, are approximately 8, suggesting the aerosol is on average fully neutralized ammonium sulfate [(NH4)2SO4]. 相似文献
8.
Derek B. Booth 《Journal of the American Water Resources Association》1990,26(3):407-417
ABSTRACT: Urbanization of a drainage basin results in pervasive hydrologic changes that in turn initiate long-term changes in stream channels. Increases in peak discharges and in durations of high flows result in either quasi-equilibrium channel expansion, where cross-section area increases in near-proportion to the discharge increase, or catastrophic channel incision, where changes occur far out of proportion to the discharge increases that initiated them. Field data and hydrologic modeling of rapidly urbanizing basins in King County, Washington, define conditions of flow, topography, geology, and channel roughness that identify streams susceptible to incision. Channel slope and geologic material are particularly critical; thus simple map overlays, nearly irrespective of contributing drainage area, provide a valuable planning tool for identification of susceptible terrain. Where such conditions exist, basal shear stress provides a quantifiable parameter for predicting likely problems, although knickpoints are typical in such settings and confound simple calculation of sediment-transport rates. Where urbanization proceeds in such areas, effective mitigation of the incision hazards requires a degree of stormwater control far in excess of standards typically applied to present development activity. 相似文献
9.
Viachaslau Filimonau Janet Dickinson Derek Robbins Mark A.J. Huijbregts 《Journal of Cleaner Production》2011,19(17-18):1917-1930
This study discusses the potential for Life Cycle Assessment (LCA) to be utilized for the environmental assessment of tourism accommodation facilities, and their contribution to global carbon footprint. To demonstrate the viability of employing LCA in the hotel sector, its simplified derivative, Life Cycle Energy Analysis (LCEA), is applied to two tourism accommodation facilities in Poole, Dorset (UK) to quantify their CO2 emissions. The results indicate that the reviewed hotels are less energy and carbon-intense than the tourism accommodation establishments reported in the literature. This may indirectly imply the continuous progress of hotel’s energy efficiency over time. The implications of the current energy use practices in the reviewed hotels are discussed and suggestions are made on how to further improve the energy performance and therefore cut the carbon footprint. Recommendations for hotel management and policy-making are developed to reduce the energy and carbon intensity of the hotel industry. A method for energy and carbon footprint analysis of outsourced laundries and breakfast services is also proposed. 相似文献
10.
Dietz R Rigét FF Sonne C Letcher RJ Backus S Born EW Kirkegaard M Muir DC 《Environmental pollution (Barking, Essex : 1987)》2007,146(1):166-173
Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean SigmaPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the SigmaPBDE concentration. The SigmaPBDE concentration had a highly significant correlation with SigmaPCB, SigmaCHL, dieldrin, HCB and SigmaHCH concentrations. We found a seasonal pattern of median SigmaPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression. 相似文献