Search results for "72"

Der Begriff der Urteilskraft bei Kant

1906

Mujeres con dependencia alcohólica: su participación en grupos de Alcohólicos Anónimos

2019

alcoholism, Alcoholics Anonymous, sexims, gender studies

Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments

2016

There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue…

Multixenobiotic resistance efflux activity in Daphnia magna and Lumbriculus variegatus

2014

Multixenobiotic resistance is a phenomenon in which ATP-binding cassette (ABC) family proteins transfer harmful compounds out of cells. Daphnia magna and Lumbriculus variegatus are model species in aquatic ecotoxicology, but the presence and activity of ABC proteins have not been well described in these species. The aim of this work was to study the presence, activity, and inhibition of ABC transport proteins in D. magna and L. variegatus. The presence of abcb1 and abcc transcripts in 8-9-day-old D. magna was investigated by qRT-PCR. The activity of MXR in D. magna and L. variegatus was explored by influx of the fluorescent ABC protein substrates rhodamine B and calcein-AM, with and without…

Lumbriculus variegatus (Annelida) biological responses and sediment sequential extractions indicate ecotoxicity of lake sediments contaminated by bio…

2018

Abstract We assessed potential ecotoxicity of lake sediments affected by biomining effluents in northeastern Finland. Growth, reproduction and behavior of the sediment-dwelling oligochaete Lumbriculus variegatus (Muller 1774) were used as ecotoxicity endpoints. Standardized chronic bioassays were used for growth and reproduction, and acute and chronic tests with Multispecies Freshwater Biomonitor (MFB) for behavior assessments. Sequential extractions were used to characterize metal bioavailability and exposure conditions in the sediments, which indicated mining-induced contamination gradients of S, Cu, Ni and U and also bioavailability gradients of S and Ni. Among the ecotoxicity endpoints,…

Effects of activated carbon ageing in three PCB contaminated sediments: Sorption efficiency and secondary effects on Lumbriculus variegatus.

2015

The sorption efficiency and possible secondary effects of activated carbon (AC) (o 63-200 μm) was studied with Lumbriculus variegatus in three PCB contaminated sediments applying long AC-sediment contact time (3 years). AC amendment efficiently reduced PCB bioavailability as determined with both, L. variegatus bioaccumulation test and passive samplers. However, dose related secondary effects of AC on egestion rate and biomass were observed (applied doses 0.25% and 2.5% sediment dry weight). The sorption capacity and secondary effects remained similar when the experiments were repeated after three years of AC-sediment contact time. Further, transmission electron microscopy (TEM) samples reve…

Responses of Lumbriculus variegatus to Activated Carbon Amendments in Uncontaminated Sediments

2012

Activated carbon (AC) amendment is a recently developed sediment remediation method. The strong hydrophobic organic contaminant sorption efficiency of AC has been shown in several studies, but effects on benthic organisms require more investigation. The AC induced effects on egestion rate, growth and reproduction of Lumbriculus variegatus were studied by applying bituminous coal based AC in three different particle size fractions, namely <63 μm (90%, AC(p)), 63-200 μm (AC(m)) and 1000 μm (AC(g)), to natural uncontaminated (HS) and artificial sediment (AS). Egestion rate, growth and reproduction decreased with increasing AC concentration and finer AC particle fractions, effects being stronge…

Emerging Raf inhibitors

2009

The Raf/MAPK kinase/extracellular-signal-regulated kinase pathway is often activated by genetic alterations in upstream signaling molecules. An integral component of this pathway, BRAF, is also activated by mutation, especially in melanoma and thyroid cancers. The Raf/MAPK kinase/extracellular-signal-regulated kinase pathway has profound effects on proliferative, apoptotic and differentiation pathways as well as the sensitivity and resistance to chemotherapeutic drugs.This review discusses targeting of Raf which could control abnormal proliferation in cancer and other proliferative diseases. The important roles that genetics plays in the response of patients to Raf inhibitors is also evalua…

The Politics of Explanatory Nationalism and the Evolution of the United Nations Agenda on Multinational Enterprises

2020

The contemporary world continues to suffer from a number of social problems that are global in scope but impact the Global South disproportionately. While broad and coordinated policy responses to overcome these problems exist, such policies are not shaped solely by the political will to address the problems. On the contrary, their content largely depends on how societies in general and the social problems in particular are routinely explained and conceptualized. We refer to these as explanatory tendencies or paradigms of explanation. As complex problems always have multiple root causes with long causal chains, explanations of these causes necessarily involve some assumptions about relevant…

The effect of peer socioeconomic status on student achievement: a meta-analysis

2010

Previous studies on the effects on students’ test scores of their peers’ socioeconomic status (SES) have reported varying results. In order to understand why researchers have alternately found small effects, large effects, or no effects at all, a meta-regression analysis including an extensive database of 30 studies on the topic was conducted. Results show that the size of the compositional effect that researchers find is strongly related to how they measure SES and to their choice of model. Measuring SES dichotomously (e.g. free lunch eligibility) or including several average SES variables in one model leads to smaller effect estimates than using a thoroughly constructed composite that inc…