36 research outputs found
Protein trafficking through the endosomal system prepares intracellular parasites for a home invasion
Toxoplasma (toxoplasmosis) and Plasmodium (malaria) use unique secretory organelles for migration, cell invasion, manipulation of host cell functions, and cell egress. In particular, the apical secretory micronemes and rhoptries of apicomplexan parasites are essential for successful host infection. New findings reveal that the contents of these organelles, which are transported through the endoplasmic reticulum (ER) and Golgi, also require the parasite endosome-like system to access their respective organelles. In this review, we discuss recent findings that demonstrate that these parasites reduced their endosomal system and modified classical regulators of this pathway for the biogenesis of apical organelles
Social Value Orientation and Endorsement of Horizontal and Vertical Individualism and Collectivism: An Exploratory Study Comparing Individuals From North America and South Korea
Individuals’ cultural tendencies of horizontal/vertical individualism and collectivism interact with their dispositional traits and contextual factors to shape social interactions. A key dispositional trait is social value orientation (SVO), a general tendency towards competition (proself) vs. cooperation (prosocial) in social exchanges. The present study (N = 1032) explored the relationship between SVO and personal cultural tendencies of horizontal/vertical individualism and collectivism in two different cultural settings, the US (a vertical individualist setting) and South Korea (a vertical collectivistic setting). We hypothesized that each value orientation would be associated with the congruent personal cultural tendency across settings. We further hypothesized that this association would be specific to the context, so that SVO would play a more relevant role where the cultural theme was less dominant. Results indicated that, across contexts, proself individuals endorsed vertical individualistic values more strongly than prosocial individuals. Conversely, prosocial individuals endorsed horizontal collectivistic values more strongly than proself individuals. In addition, the effect of SVO was different in the two cultural contexts. Compared to proself individuals, prosocial individuals endorsed horizontal collectivism more strongly in the US context, and horizontal individualism less strongly in the Korea context. Theoretical implications and limitations of the findings, as well as directions for future work are discussed
Trace metal distribution in the bed, bank and suspended sediment of the Ravensbourne River and its implication for sediment monitoring in an urban river
Purpose This study aims to identify a suitable sediment compartment for sediment quality monitoring by: (a) studying the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the bed, bank and suspended sediment compartments of the Ravensbourne River to establish any differences in trace metal concentrations with compartment; (b) determining the influence of sediment particle size fractions ( 0.05) in the concentrations of metals between the suspended sediment and the < 63 μm bed sediment fraction, but there was a significant difference (p < 0.05) between the suspended sediment and the < 63 μm bank sediment fraction. There were also significant differences between the concentrations of metals in the < 63 μm and the 63 μm–2 mm fractions. Generally, the Ravensbourne River did not comply with the draft UK sediment quality guidelines for the metals analysed. Conclusions This study shows the importance of identifying a suitable sediment compartment to sample for compliance with sediment quality standards. The bed and suspended sediments are the most widely used sediment compartments for sediment monitoring, but collecting sufficient mass of the < 63 μm sediment fraction for monitoring presents a challenge for urban gravel bed rivers like the Ravensbourne River. It seems appropriate to establish individual monitoring regimes for different rivers