Integrative assessment of selenium speciation, biogeochemistry, and distribution in a northern coldwater ecosystem

2014 ◽  
Vol 10 (4) ◽  
pp. 543-554 ◽  
Author(s):  
David M Janz ◽  
Karsten Liber ◽  
Ingrid J Pickering ◽  
Cheryl IE Wiramanaden ◽  
Shari A Weech ◽  
...  
1999 ◽  
Vol 40 (11-12) ◽  
pp. 139-146 ◽  
Author(s):  
Mika A. Kähkönen ◽  
Mikko Liukkonen ◽  
Christoph Wittmann ◽  
Kimmo P. Suominen ◽  
Mirja S. Salkinoja-Salonen

Sediments were dated and the quality assessed by polyphasic approach in an area of Lake Saimaa, which has received waste water from bleached kraft pulp production since 1954. The chosen nonrecipient forest Lake Pyylampi was situated in the same area. The activities of the enzymes butyrate-esterase and aminopeptidase were depressed at the depth of 2 to 8 cm in the recipient but not in the forst lake sediment. In the same layers the contents of EOX-C1 and toxicity to Vibrio fischeri were very high compared to those above or below. Toxicity to microbial community in the 2 to 8 cm layer was also indicated by a gap in the ATP content and a drop in diatom species richness from the 70 species to < 50 reflecting decreased water quality of the pelagic area. All these changes dated to the period of heavy organic halogen discharges, from 1960 to late 1980s, which led to sediment accumulation of solvent soluble halogen at a depth of 2 to 8 cm, to 6.4 g m−2 (cm)−1. In the most polluted sediment layers heavy metal accumulation was too little to be related to the toxicity of these layers. Almost complete recovery of both the sediment microbial ecosystems and of the pelagic diatoms occurred after elemental chlorine was completely substituted by chlorine dioxide and biological treatment adopted for wastewaters. Butyrate-esterase and aminopeptidase, but not phosphatase, activities correlated positively with the ATP content of the sediment. Butyrate-esterase may be used as a tool to estimate microbial biomass.


Author(s):  
Frank Abrahams

This chapter aligns the tenets of critical pedagogy with current practices of assessment in the United States. The author posits that critical pedagogy is an appropriate lens through which to view assessment, and argues against the hegemonic practices that support marginalization of students. Grounded in critical theory and based on Marxist ideals, the content supports the notion of teaching and learning as a partnership where the desire to empower and transform the learner, and open possibilities for the learner to view the world and themselves in that world, are primary goals. Political mandates to evaluate teacher performance and student learning are presented and discussed. In addition to the formative and summative assessments that teachers routinely do to students, the author suggests integrative assessment, where students with the teacher reflect together on the learning experience and its outcomes. The chapter includes specific examples from the author’s own teaching that operationalize the ideas presented.


2015 ◽  
Vol 17 (8) ◽  
pp. 753-765 ◽  
Author(s):  
Ali F. El Mehdawi ◽  
Stormy D. Lindblom ◽  
Jennifer J. Cappa ◽  
Sirine C. Fakra ◽  
Elizabeth A. H. Pilon-Smits

2017 ◽  
Vol 187 ◽  
pp. 1-8 ◽  
Author(s):  
C.M. Lanctôt ◽  
S.D. Melvin ◽  
T. Cresswell
Keyword(s):  

Author(s):  
Tony R. Smith ◽  
Vaughn J. Crichlow ◽  
O. Nicholas Robertson ◽  
Jason D. Scott

Phytotaxa ◽  
2021 ◽  
Vol 500 (2) ◽  
pp. 61-94
Author(s):  
JÉSSICA LEÃO BARBOSA TANAJURA ◽  
CAROLINA SANTOS PINHO ◽  
RILQUER MASCARENHAS DA SILVA ◽  
MARIA LUIZA SILVEIRA DE CARVALHO

This study aimed to assess the diversity of species in the Espinhaço Range (ER), eastern Brazil, using as a model the diverse plant family Gentianaceae and focusing on the Parque Municipal de Mucugê—Projeto Sempre Viva (PMM), a conservation unit with predominance of  “campo rupestre”. For this purpose, fieldwork expeditions were carried out between the years 2016–2018 along with a survey of species of this family recorded for this conservation unit in public databases. For comparative purposes, the listing of species from other five areas of the ER were also surveyed and we modeled the distribution of species endemic to these mountains, taking into account that they have their restrict distribution, high habitat specificity and importance to the ecosystem. The results indicated the presence of 33 species of Gentianaceae for the ER, eight of them occurring in the PMM. Comparatively, the results pointed to a greater floristic similarity between the PMM, Pico das Almas and Catolés, due to the presence of seven common species. Predictive distribution modeling supports high endemicity of the analyzed species, given their low environmental suitability outside the ER. The models also allowed us to identify possible areas showing high Wallacean shortfall for these species. Thus, the results reinforce the importance of field work, access to physical and digital botanical collections and the integrated use of tools for a more reliable survey of biodiversity.


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