scholarly journals Combination of theoretical and in-situ experimental investigations of the role of lithium dopant in manganese nitride: a two-stage reagent for ammonia synthesis

2020 ◽  
Author(s):  
Said Laassiri ◽  
Constantinos D. Zeinalipour-Yazdi ◽  
Nicolas Bion ◽  
Richard Charles Arthur Catlow ◽  
Justin Hargreaves

Manganese nitride related materials are of interest as two-stage reagents for ammonia synthesis via nitrogen chemical looping. However, unless doped with a co-cation, manganese nitrides are thermochemically stable and high...

2019 ◽  
Author(s):  
Konrad Bresin

Trait impulsivity has long been proposed to play a role in aggression, but the results across studies have been mixed. One possible explanation for the mixed results is that impulsivity is a multifaceted construct and some, but not all, facets are related to aggression. The goal of the current meta-analysis was to determine the relation between the different facets of impulsivity (i.e., negative urgency, positive urgency, lack of premeditation, lack of perseverance, and sensation seeking) and aggression. The results from 93 papers with 105 unique samples (N = 36, 215) showed significant and small-to-medium correlations between each facet of impulsivity and aggression across several different forms of aggression, with more impulsivity being associated with more aggression. Moreover, negative urgency (r = .24, 95% [.18, .29]), positive urgency (r = .34, 95% [.19, .44]), and lack of premeditation (r = .23, 95% [.20, .26]) had significantly stronger associations with aggression than the other scales (rs < .18). Two-stage meta-analytic structural equation modeling showed that these effects were not due to overlap among facets of impulsivity. These results help advance the field of aggression research by clarifying the role of impulsivity and may be of interest to researchers and practitioners in several disciplines.


2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.


2020 ◽  
Author(s):  
Kimberly D. Myers ◽  
◽  
Katrina Lee Jewell ◽  
P.S.K. Knappett ◽  
Mehtaz M. Lipsi ◽  
...  

2021 ◽  
pp. 089331892199807
Author(s):  
Jonathan Clifton ◽  
Fernando Fachin ◽  
François Cooren

To date there has been little work that uses fine-grained interactional analyses of the in situ doing of leadership to make visible the role of non-human as well as human actants in this process. Using transcripts of naturally-occurring interaction as data, this study seeks to show how leadership is co-achieved by artefacts as an in-situ accomplishment. To do this we situate this study within recent work on distributed leadership and argue that it is not only distributed across human actors, but also across networks that include both human and non-human actors. Taking a discursive approach to leadership, we draw on Actor Network Theory and adopt a ventriloquial approach to sociomateriality as inspired by the Montreal School of organizational communication. Findings indicate that artefacts “do” leadership when a hybrid presence is made relevant to the interaction and when this presence provides authoritative grounds for influencing others to achieve the group’s goals.


2021 ◽  
Vol 22 (7) ◽  
pp. 3787
Author(s):  
Hussam Ibrahim ◽  
Philipp Reus ◽  
Anna Katharina Mundorf ◽  
Anna-Lena Grothoff ◽  
Valerie Rudenko ◽  
...  

Repressor protein period (PER) complexes play a central role in the molecular oscillator mechanism of the mammalian circadian clock. While the main role of nuclear PER complexes is transcriptional repression, much less is known about the functions of cytoplasmic PER complexes. We found with a biochemical screen for PER2-interacting proteins that the small GTPase regulator GTPase-activating protein and VPS9 domain-containing protein 1 (GAPVD1), which has been identified previously as a component of cytoplasmic PER complexes in mice, is also a bona fide component of human PER complexes. We show that in situ GAPVD1 is closely associated with casein kinase 1 delta (CSNK1D), a kinase that regulates PER2 levels through a phosphoswitch mechanism, and that CSNK1D regulates the phosphorylation of GAPVD1. Moreover, phosphorylation determines the kinetics of GAPVD1 degradation and is controlled by PER2 and a C-terminal autoinhibitory domain in CSNK1D, indicating that the regulation of GAPVD1 phosphorylation is a novel function of cytoplasmic PER complexes and might be part of the oscillator mechanism or an output function of the circadian clock.


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