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Water Quality Assessment of a Tropical Mexican Lake Using Multivariate Statistical Techniques

Journal of Environmental Protection 2015年第3期6卷 215-224页

作者： Jessica Badillo-Camacho eire Reynaga-delgado Isela Barcelo-Quintal Pedro f.Zarate del Valle Ulrico J.Lopez-Chuken Eulogio Orozco-Guareno Jorge Israel AlvarezBobadilla Sergio Gomez-Salazar departamento de Quimica Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico departamento de farmacobiologia Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico departamento de Ciencias Basicas Universidad Autonoma MetropolitanaUnidad AzcapotzalcoMexico D.F.Mexico facultad de Ciencias Quimicas Universidad Autonoma de Nuevo LeonSan Nicolas de los GarzaMexico departamento de Ingenieria Quimica Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico

Water quality of Mexican tropical lake Chapala was assessed through multivariate statistical techniques, cluster analysis (CA) and principal component analysis (PCA) at ten different monitoring sites for ten physicochemical variables and six metals. This study evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality. from descriptive statistics results, the highest concentrations of metals occurred during the dry season, and this trend was explained by the fact that an unusual rainy event occurred during the month of f.bruary 2009 and brought metals into the lake by runoffs from nearby mountains. According to international criteria for water consumption by aquatic organisms [USEPA], only Zn concentration values were below these criteria whereas the values of Ni, Pb, Cd and fe were above the corresponding values set in these criteria (Ni: 52 μg·L-1, Pb: 2.5 μg·L-1, Cd: 0.25 μg·L-1, and fe: 1000 μg·L-1). The correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Seven significant cluster groups of sampling locations—(sites 4 and 5), (sites 3 and 9), (site 7), (site 10), (sites 2 and 6), (site 8) and (site 1)— were detected on the basis of similarity of their water quality. The results revealed that the stress exerted on the lake caused by waste sources follows the order: domestic > agricultural > industrial.

关键词： Multivariate Statistical Analysis toxic Metals Water Quality Lake Pollution

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Characterization of Chemical Constituents of Luffa operculata(Cucurbitaceae)

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American Journal of Analytical Chemistry 2011年第8期2卷 989-995页

作者： Cleia Rocha de Sousa feitosa Roberio Costa da Silva Raimundo braz-filho Jane eire Silva Alencar de Menezes Sonia Maria Costa Siqueira francisco Jose Queiroz Monte Programa de Pos-Graduacao em Quimica-DQOI-CC Universidade Federal do CearaFortalezaBrazil Universidade Estadual do Norte fluminense Darcy Ribeiro Campos dos GoytacazesBrazil Universidade Estadual do Ceara Faculdades de Educacao de CrateusFortalezaBrazil Universidade Estadual do Ceara Itapipoca FortalezaBrazil Universidade Estadual do Ceara e campos do ItaperiFortalezaBrazil

A mixture of new ceramides (1, 2, 3, 4 and 5) together with a binary mixture of ceramides with long chain alkyl (6 and 7), triterpenoid (10) and steroids (11 and 12) have been isolated from bark of the fruits and of the stems of Luffa operculata (Cucurbitaceae). The structures were elucidated by comprehensive spectro- scopic analysis including 1H and 13C NMR, dePT (distortionless enhancement by polarization transfer), COSY (correlated spectroscopy), HMQC (heteronuclear multiple quantum coherence), HMBC (heteronu- clear multiple bond connectivity), IR (infrared), HR-ESI-MS (electrospray ionization-high resolution mass spectra) and LR-MS (low resolution electron ionization mass spectra) experiments. All the ceramides are reported for the first time in Cucurbitaceae and this is the first report of the rare triterpene 10 isolated from Luffa operculata. The ceramides 6 and 7 showed a high acetylcholine esterase inhibitory effect.

关键词： Cucurbitaceae Ceramides Triterpenes Spectroscopic Data

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OBSERVATIONS ON THE QUATERNARY GEOLOGY Of THE LADAKH RANGE, NORTHWEST INDIAN HIMALAYA

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地学前缘 2000年第S1期7卷 49-49页

作者： W. A. Mitchell 1, P. Coxon 2 (1 department of Geology, University of Luton, LU1 3JU, UK 2 department of Geography, Trinity College Dublin 2, eire)

Ladakh is a critical area in a determination of the nature of Himalayan glaciation as it lies north of the arid area of Zanskar, where the glacial extent was limited through much of the Late Pleistocene, and south of the Karakoram Range which remains the most heavily glaciated area outside the polar areas and was a centre of extensive glaciation during the *** variation in glacial style and extent across the Himalaya may reflect the interplay between monsoon driven south\|westerly air masses from the Indian Ocean and the westerly air masses from the Mediterranean/Black Sea areas. This paper reports on the first detailed geomorphological observations from within the Ladakh Range and demonstrates the former existence of large glaciers with a number of distinct limits to allow a first approximation of the glacial sequence. Samples for OSL age estimates are currently being processed to constrain a chronostratigraphy. No evidence has been observed for glaciation within the main Indus valley, but large (>80m high) moraine ridges indicate the former existence of glaciers entering from the southern tributary valleys of the Ladakh Range, descending to altitudes of c. *** Nimu glacier diverted the Indus southwards to erode a new valley with the abandonment of its former valley that can be traced westwards. In the tributary valley north of Leh, impressive termino\|lateral moraine ridges appear to lie on top of older weathered smaller moraine ridges, suggesting a more complex glacial sequence than previously reported.

关键词： Ladakh glaciation catastrophic floods OSL age estimates

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