Abiotic and biotic processes that drive carboxylation and decarboxylation reactions

© 2020 Walter de Gruyter GmbH, Berlin/Boston 2020. Carboxylation and decarboxylation are two fundamental classes of reactions that impact the cycling of carbon in and on Earth's crust. These reactions play important roles in both long-term (primarily abiotic) and short-term (primarily biotic) carbon cycling. Long-term cycling is important in the subsurface and at subduction zones where organic carbon is decomposed and outgassed or recycled back to the mantle. Short-term reactions are driven by biology and have the ability to rapidly convert CO2 to biomass and vice versa. For instance, carboxylation is a critical reaction in primary production and metabolic pathways like photosynthesis in which sunlight provides energy to drive carbon fixation, whereas decarboxylation is a critical reaction in metabolic pathways like respiration and the tricarboxylic acid cycle. Early life and prebiotic chemistry on Earth likely relied heavily upon the abiotic synthesis of carboxylic acids. Over time, life has diversified (de)carboxylation reactions and incorporated them into many facets of cellular metabolism. Here we present a broad overview of the importance of carboxylation and decarboxylation reactions from both abiotic and biotic perspectives to highlight the importance of these reactions and compounds to planetary evolution

A distributed national stored collection: Testing the possibilities

This paper reports on a study of the holdings of a single discipline (Design) by a single institution (RMIT University Library) in order to test for the possibility of a form of distributed national storage in Australia. The study was undertaken using OCLC Collection Analysis software and the WorldCat database. The collection of RMIT University Library is compared with two ‘groups’ of libraries, the first consisting of seven Victorian academic library collections, and the second of three Melbourne-based non-academic libraries considered to have strong Design collections. Conclusions indicate that for this discipline a form of distributed storage is already in place, with the RMIT University Library collection making a considerable and complementary contribution to the state wide holdings

HCV IRES manipulates the ribosome to promote the switch from translation initiation to elongation.

The internal ribosome entry site (IRES) of the hepatitis C virus (HCV) drives noncanonical initiation of protein synthesis necessary for viral replication. Functional studies of the HCV IRES have focused on 80S ribosome formation but have not explored its role after the 80S ribosome is poised at the start codon. Here, we report that mutations of an IRES domain that docks in the 40S subunit's decoding groove cause only a local perturbation in IRES structure and result in conformational changes in the IRES-rabbit 40S subunit complex. Functionally, the mutations decrease IRES activity by inhibiting the first ribosomal translocation event, and modeling results suggest that this effect occurs through an interaction with a single ribosomal protein. The ability of the HCV IRES to manipulate the ribosome provides insight into how the ribosome's structure and function can be altered by bound RNAs, including those derived from cellular invaders

Peer-provided psychological intervention for Syrian refugees: results of a randomised controlled trial on the effectiveness of Problem Management Plus

Background The mental health burden among refugees in high-income countries (HICs) is high, whereas access to mental healthcare can be limited. Objective To examine the effectiveness of a peer-provided psychological intervention (Problem Management Plus; PM+) in reducing symptoms of common mental disorders (CMDs) among Syrian refugees in the Netherlands. Methods We conducted a single-blind, randomised controlled trial among adult Syrian refugees recruited in March 2019–December 2021 (No. NTR7552). Individuals with psychological distress (Kessler Psychological Distress Scale (K10) >15) and functional impairment (WHO Disability Assessment Schedule (WHODAS 2.0) >16) were allocated to PM+ in addition to care as usual (PM+/CAU) or CAU only. Participants were reassessed at 1-week and 3-month follow-up. Primary outcome was depression/anxiety combined (Hopkins Symptom Checklist; HSCL-25) at 3-month follow-up. Secondary outcomes included depression (HSCL-25), anxiety (HSCL-25), post-traumatic stress disorder (PTSD) symptoms (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; PCL-5), impairment (WHODAS 2.0) and self-identified problems (PSYCHLOPS; Psychological Outcomes Profiles). Primary analysis was intention-to-treat. Findings Participants (n=206; mean age=37 years, 62% men) were randomised into PM+/CAU (n=103) or CAU (n=103). At 3-month follow-up, PM+/CAU had greater reductions on depression/anxiety relative to CAU (mean difference −0.25; 95% CI −0.385 to −0.122; p=0.0001, Cohen’s d=0.41). PM+/CAU also showed greater reductions on depression (p=0.0002, Cohen’s d=0.42), anxiety (p=0.001, Cohen’s d=0.27), PTSD symptoms (p=0.0005, Cohen’s d=0.39) and self-identified problems (p=0.03, Cohen’s d=0.26), but not on impairment (p=0.084, Cohen’s d=0.21). Conclusions PM+ effectively reduces symptoms of CMDs among Syrian refugees. A strength was high retention at follow-up. Generalisability is limited by predominantly including refugees with a resident permit. Clinical implications Peer-provided psychological interventions should be considered for scale-up in HICs

Trypanosoma brucei gambiense group 1 is distinguished by a unique amino acid substitution in the HpHb receptor implicated in human serum resistance

Trypanosoma brucei rhodesiense (Tbr) and T. b. gambiense (Tbg), causative agents of Human African Trypanosomiasis (sleeping sickness) in Africa, have evolved alternative mechanisms of resisting the activity of trypanosome lytic factors (TLFs), components of innate immunity in human serum that protect against infection by other African trypanosomes. In Tbr, lytic activity is suppressed by the Tbr-specific serum-resistance associated (SRA) protein. The mechanism in Tbg is less well understood but has been hypothesized to involve altered activity and expression of haptoglobin haemoglobin receptor (HpHbR). HpHbR has been shown to facilitate internalization of TLF-1 in T.b. brucei (Tbb), a member of the T. brucei species complex that is susceptible to human serum. By evaluating the genetic variability of HpHbR in a comprehensive geographical and taxonomic context, we show that a single substitution that replaces leucine with serine at position 210 is conserved in the most widespread form of Tbg (Tbg group 1) and not found in related taxa, which are either human serum susceptible (Tbb) or known to resist lysis via an alternative mechanism (Tbr and Tbg group 2). We hypothesize that this single substitution contributes to reduced uptake of TLF and thus may play a key role in conferring serum resistance to Tbg group 1. In contrast, similarity in HpHbR sequence among isolates of Tbg group 2 and Tbb/Tbr provides further evidence that human serum resistance in Tbg group 2 is likely independent of HpHbR functio

Numerical description of discharge characteristics of the plasma needle

The plasma needle is a small atmospheric, nonthermal, radio-frequency discharge, generated at the tip of a needle, which can be used for localized disinfection of biological tissues. Although several experiments have characterized various qualities of the plasma needle, discharge characteristics and electrical properties are still not well known. In order to provide initial estimates on electrical properties and quantities such as particle densities, we employed a two-dimensional, time-dependent fluid model to describe the plasma needle. In this model the balance equation is solved in the drift-diffusion approach for various species and the electron energy, as well as Poisson's equation. We found that the plasma production occurs in the sheath region and results in a steady flux of reactive species outwards. Even at small (< 0.1%) admixtures of N-2 to the He background, N-2(+) is the dominant ion. The electron density is typically 10(11) cm(-3) and the dissipated power is in the order of 10 mW. These results are consistent with the experimental data available and can give direction to the practical development of the plasma needle. (c) 2005 American Institute of Physics

Differences between <i>Trypanosoma brucei gambiense</i> groups 1 and 2 in their resistance to killing by Trypanolytic factor 1

&lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; The three sub-species of &lt;i&gt;Trypanosoma brucei&lt;/i&gt; are important pathogens of sub-Saharan Africa. &lt;i&gt;T. b. brucei&lt;/i&gt; is unable to infect humans due to sensitivity to trypanosome lytic factors (TLF) 1 and 2 found in human serum. &lt;i&gt;T. b. rhodesiense&lt;/i&gt; and &lt;i&gt;T. b. gambiense&lt;/i&gt; are able to resist lysis by TLF. There are two distinct sub-groups of &lt;i&gt;T. b. gambiense&lt;/i&gt; that differ genetically and by human serum resistance phenotypes. Group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; have an invariant phenotype whereas group 2 show variable resistance. Previous data indicated that group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; are resistant to TLF-1 due in-part to reduced uptake of TLF-1 mediated by reduced expression of the TLF-1 receptor (the haptoglobin-hemoglobin receptor (&lt;i&gt;HpHbR&lt;/i&gt;)) gene. Here we investigate if this is also true in group 2 parasites.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methodology:&lt;/b&gt; Isogenic resistant and sensitive group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; were derived and compared to other T. brucei parasites. Both resistant and sensitive lines express the &lt;i&gt;HpHbR&lt;/i&gt; gene at similar levels and internalized fluorescently labeled TLF-1 similar fashion to &lt;i&gt;T. b. brucei&lt;/i&gt;. Both resistant and sensitive group 2, as well as group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt;, internalize recombinant APOL1, but only sensitive group 2 parasites are lysed.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Our data indicate that, despite group 1 &lt;i&gt;T. b. gambiense&lt;/i&gt; avoiding TLF-1, it is resistant to the main lytic component, APOL1. Similarly group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; is innately resistant to APOL1, which could be based on the same mechanism. However, group 2 &lt;i&gt;T. b. gambiense&lt;/i&gt; variably displays this phenotype and expression does not appear to correlate with a change in expression site or expression of &lt;i&gt;HpHbR&lt;/i&gt;. Thus there are differences in the mechanism of human serum resistance between &lt;i&gt;T. b. gambiense&lt;/i&gt; groups 1 and 2.&lt;/p&gt

Peer-provided psychological intervention for Syrian refugees: results of a randomised controlled trial on the effectiveness of Problem Management Plus

Background The mental health burden among refugees in high-income countries (HICs) is high, whereas access to mental healthcare can be limited. Objective To examine the effectiveness of a peer-provided psychological intervention (Problem Management Plus; PM+) in reducing symptoms of common mental disorders (CMDs) among Syrian refugees in the Netherlands. Methods We conducted a single-blind, randomised controlled trial among adult Syrian refugees recruited in March 2019–December 2021 (No. NTR7552). Individuals with psychological distress (Kessler Psychological Distress Scale (K10) >15) and functional impairment (WHO Disability Assessment Schedule (WHODAS 2.0) >16) were allocated to PM+ in addition to care as usual (PM+/CAU) or CAU only. Participants were reassessed at 1-week and 3-month follow-up. Primary outcome was depression/anxiety combined (Hopkins Symptom Checklist; HSCL-25) at 3-month follow-up. Secondary outcomes included depression (HSCL-25), anxiety (HSCL-25), post-traumatic stress disorder (PTSD) symptoms (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; PCL-5), impairment (WHODAS 2.0) and self-identified problems (PSYCHLOPS; Psychological Outcomes Profiles). Primary analysis was intention-to-treat. Findings Participants (n=206; mean age=37 years, 62% men) were randomised into PM+/CAU (n=103) or CAU (n=103). At 3-month follow-up, PM+/CAU had greater reductions on depression/anxiety relative to CAU (mean difference −0.25; 95% CI −0.385 to −0.122; p=0.0001, Cohen’s d=0.41). PM+/CAU also showed greater reductions on depression (p=0.0002, Cohen’s d=0.42), anxiety (p=0.001, Cohen’s d=0.27), PTSD symptoms (p=0.0005, Cohen’s d=0.39) and self-identified problems (p=0.03, Cohen’s d=0.26), but not on impairment (p=0.084, Cohen’s d=0.21). Conclusions PM+ effectively reduces symptoms of CMDs among Syrian refugees. A strength was high retention at follow-up. Generalisability is limited by predominantly including refugees with a resident permit. Clinical implications Peer-provided psychological interventions should be considered for scale-up in HICs

The 5′ Leader of the mRNA Encoding the Mouse Neurotrophin Receptor TrkB Contains Two Internal Ribosomal Entry Sites that Are Differentially Regulated

A single internal ribosomal entry site (IRES) in conjunction with IRES transactivating factors (ITAFs) is sufficient to recruit the translational machinery to a eukaryotic mRNA independent of the cap structure. However, we demonstrate that the mouse TrkB mRNA contains two independent IRESes. The mouse TrkB mRNA consists of one of two 5′ leaders (1428 nt and 448 nt), both of which include the common 3′ exon (Ex2, 344 nt). Dicistronic RNA transfections and in vitro translation of monocistronic RNA demonstrated that both full-length 5′ leaders, as well as Ex2, exhibit IRES activity indicating the IRES is located within Ex2. Additional analysis of the upstream sequences demonstrated that the first 260 nt of exon 1 (Ex1a) also contains an IRES. Dicistronic RNA transfections into SH-SY5Y cells showed the Ex1a IRES is constitutively active. However, the Ex2 IRES is only active in response to retinoic acid induced neural differentiation, a state which correlates with the synthesis of the ITAF polypyrimidine tract binding protein (PTB1). Correspondingly, addition or knock-down of PTB1 altered Ex2, but not Ex1a IRES activity in vitro and ex vivo, respectively. These results demonstrate that the two functionally independent IRESes within the mouse TrkB 5′ leader are differentially regulated, in part by PTB1