How Effective Is Help on the Doorstep? A Longitudinal Evaluation of Community-Based Organisation Support

Community-based responses have a lengthy history. The ravages of HIV on family functioning has included a widespread community response. Although much funding has been invested in front line community-based organisations (CBO), there was no equal investment in evaluations. This study was set up to compare children aged 9–13 years old, randomly sampled from two South African provinces, who had not received CBO support over time (YC) with a group of similarly aged children who were CBO attenders (CCC). YC baseline refusal rate was 2.5% and retention rate was 97%. CCC baseline refusal rate was 0.7% and retention rate was 86.5%. 1848 children were included—446 CBO attenders compared to 1402 9–13 year olds drawn from a random sample of high-HIV prevalence areas. Data were gathered at baseline and 12–15 months follow-up. Standardised measures recorded demographics, violence and abuse, mental health, social and educational factors. Multivariate regression analyses revealed that children attending CBOs had lower odds of experiencing weekly domestic conflict between adults in their home (OR 0.17; 95% CI 0.09, 0.32), domestic violence (OR 0.22; 95% CI 0.08, 0.62), or abuse (OR 0.11; 95% CI 0.05, 0.25) at follow-up compared to participants without CBO contact. CBO attenders had lower odds of suicidal ideation (OR 0.41; 95% CI 0.18, 0.91), fewer depressive symptoms (B = -0.40; 95% CI -0.62, -0.17), less perceived stigma (B = -0.37; 95% CI -0.57, -0.18), fewer peer problems (B = -1.08; 95% CI -1.29, -0.86) and fewer conduct problems (B = -0.77; 95% CI -0.95, -0.60) at follow-up. In addition, CBO contact was associated with more prosocial behaviours at follow-up (B = 1.40; 95% CI 1.13, 1.67). No associations were observed between CBO contact and parental praise or post-traumatic symptoms. These results suggest that CBO exposure is associated with behavioural and mental health benefits for children over time. More severe psychopathology was not affected by attendance and may need more specialised input.     

Immune gene variability influences roe deer natal dispersal

Dispersal is a key life‐history trait governing the response of individuals, populations and species to changing environmental conditions. In the context of global change, it is therefore essential to better understand the respective role of condition‐, phenotype‐ and genetic‐dependent drivers of dispersal behaviour. Although the importance of immune function and pathogen infestation in determining patterns of dispersal is increasingly recognised, no study to our knowledge has yet investigated the influence of immune gene variability on dispersal behaviour. Here, we filled this knowledge gap by assessing whether individual heterozygosity at five immune gene loci (one from the Major histocompatibility complex and four from encoding Toll‐like receptors) influences roe deer natal dispersal. We found that dispersal propensity was affected by immune gene diversity, suggesting potential pathogen‐mediated selection through over‐dominance. However, the direction of this effect differed between high and low quality individuals, suggesting that dispersal propensity is driven by two different mechanisms. In support of the condition‐dependent dispersal hypothesis, dispersal propensity increased with increasing body mass and, among high quality individuals only (standardized body mass > 18 kg), with increasing immune gene diversity. However, among poor quality individuals, we observed the opposite pattern such that dispersal propensity was higher for individuals with lower immune gene diversity. We suggest that these poor quality individuals expressed an emergency dispersal tactic in an attempt to escape a heavily infested environment associated with poor fitness prospects. Our results have potentially important consequences in terms of population genetics and demography, as well as host–pathogen evolution.     

Ecological strategies in stable and disturbed environments depend on species specialisation

Ecological strategies are integral to understanding species survival in different environments. However, how habitat specialisation is involved in such strategies is not fully understood, particularly in heterogeneous and disturbed environments. Here, we studied the trait associations between specialisation, dispersal ability, competitiveness, reproductive investment and survival rate in a spatially explicit metacommunity model under various disturbance rates. Though no unique trait values were associated with specialisation, relationships were uncovered depending on environmental factors. We found strong trait associations mainly for generalist species, while specialist species exhibited a larger range of trait combinations. Trait associations were driven first by the disturbance rate and second by species' dispersal ability and generation overlap. With disturbance, low dispersal ability was strongly selected against, for specialists as well as for generalists. Our results demonstrate that habitat specialisation is critical for the emergence of trait strategies in metacommunities and that disturbance in interaction with dispersal ability limits not only the range of trait values but also the type of possible trait associations.     

Influence of root and leaf traits on the uptake of nutrients in cover crops

Plant and Soil - The objectives of this study were to determine the spatial structure of soil respiration (Rs) in a naturally-regenerated longleaf pine forest and to assess the ecological factors...     

Long-term,large scale cryopreservation of insect cells at −80 °C

Standard tissue culture methods advise freezing cells in small aliquots (≤1 × 10⁷ cells in 1 mL), and storing in liquid nitrogen. This is inconvenient for laboratories culturing large quantities of insect cells for recombinant baculovirus expression, owing to the length of time taken to produce large scale cultures from small aliquots of cells. Liquid nitrogen storage requires use of specialized cryovials, personal protective equipment and oxygen monitoring systems. This paper describes the long-term, large scale cryopreservation of 8 × 10⁸ insect cells at −80 °C, using standard 50 mL conical tubes to contain a 40 mL cell suspension. Sf9, Sf21 and High 5 cells were recovered with a viability > 90 % after storage for one year under these conditions, which compared favorably with the viability of cells stored in liquid nitrogen for the same length of time. Addition of green fluorescent protein encoding baculovirus demonstrated that cells were “expression ready” immediately post thaw. Our method enables large scale cultures to be recovered rapidly from stocks cryopreserved at −80 °C, thus avoiding the inconvenience, hazards and expense associated with liquid nitrogen.

Electronic supplementary material

The online version of this article (doi:10.1007/s10616-014-9781-5) contains supplementary material, which is available to authorized users.     

Horticultural mineral oil influences Plum pox virus transmission by Myzus persicae

The residual activity of horticultural mineral oil (HMO) on the ability of green peach aphids, Myzus persicae (Sulzer), (GPA) to transmit Plum pox virus (PPV) to peach was measured by infection rates of detached leaves from plants sprayed with either HMO or water as a control that were inoculated using transfer of 25 viruliferous aphids per leaf at 0, 2, 4, 7, 9, 11 and 14 days after treatment (DAT). Persistent effects of HMO residue on the probing and feeding behaviours of GPA were also monitored with the electrical penetration graph (EPG) system. For glasshouse‐grown peach seedlings, the residual activity of HMO reduced PPV infection rates by more than 58% for up to 4 DAT following an initial reduction of approximately 81%. EPG recordings of GPA feeding behaviour showed that HMO significantly delayed first feeding probes and first intracellular punctures by more than 50 min without changing the ensuing stylet penetration behaviour. Applying HMO reduced virus infection rates for up to a week depending on the environmental conditions. EPG monitoring of aphid probing showed that HMO reduced the mean duration and mean number of potential drop (PD) phase feeding occurrences, compared with the water control. A reduction in the PD that has been shown to be related to the transmission of non‐persistently transmitted viruses may partly explain the reduction in PPV infection rates.     

Iron chelation and 2‐oxoglutarate‐dependent dioxygenase inhibition suppress mantle cell lymphoma's cyclin D1

The patients with mantle cell lymphoma (MCL) have translocation t(11;14) associated with cyclin D1 overexpression. We observed that iron (an essential cofactor of dioxygenases including prolyl hydroxylases [PHDs]) depletion by deferoxamine blocked MCL cells’ proliferation, increased expression of DNA damage marker γH2AX, induced cell cycle arrest and decreased cyclin D1 level. Treatment of MCL cell lines with dimethyloxalylglycine, which blocks dioxygenases involving PHDs by competing with their substrate 2‐oxoglutarate, leads to their decreased proliferation and the decrease of cyclin D1 level. We then postulated that loss of EGLN2/PHD1 in MCL cells may lead to down‐regulation of cyclin D1 by blocking the degradation of FOXO3A, a cyclin D1 suppressor. However, the CRISPR/Cas9‐based loss‐of‐function of EGLN2/PHD1 did not affect cyclin D1 expression and the loss of FOXO3A did not restore cyclin D1 levels after iron chelation. These data suggest that expression of cyclin D1 in MCL is not controlled by ENGL2/PHD1‐FOXO3A pathway and that chelation‐ and 2‐oxoglutarate competition‐mediated down‐regulation of cyclin D1 in MCL cells is driven by yet unknown mechanism involving iron‐ and 2‐oxoglutarate‐dependent dioxygenases other than PHD1. These data support further exploration of the use of iron chelation and 2‐oxoglutarate‐dependent dioxygenase inhibitors as a novel therapy of MCL.     

A highly standardized and characterized human platelet lysate for efficient and reproducible expansion of human bone marrow mesenchymal stromal cells

BackgroundHuman platelet lysate (hPL) represents a powerful alternative to fetal bovine serum (FBS) for human mesenchymal stromal cell (hMSC) expansion. However, the large variability in hPL sources and production protocols gives rise to discrepancies in product quality, characterization and poor batch-to-batch standardization.MethodshPL prepared with more than 200 donors (200+DhPL) or with five donors (5DhPL) were compared in terms of growth factor (GF) contents and biochemical analysis. A multiple protein assay and proteomic analysis were performed to further characterize 200+DhPL batches. We also compared the phenotypic and functional characteristics of bone marrow (BM)-hMSCs grown in 200+DhPL versus FBS+basic fibroblast growth factor (bFGF).ResultsBy contrast to 5DhPL, industrial 200+DhPL displayed a strong standardization of GF contents and biochemical characteristics. We identified specific plasmatic components and platelet-released factors as the most relevant markers for the evaluation of the standardization of hPL batches. We used a multiplex assay and proteomic analysis of 200+DhPL to establish a proteomic signature and demonstrated the robust standardization of batches. 200+DhPL was shown to improve and standardize BM-hMSC expansion compared with FBS+bFGF. The levels of expression of BM-hMSC membrane markers were found to be much more homogeneous between batches when cells were cultured in 200+DhPL. BM-hMSCs cultured in parallel under both conditions displayed similar adipogenic and osteogenic differentiation potential and immunosuppressive properties.ConclusionsWe report a standardization of hPL and the importance of such standardization for the efficient amplification of more homogeneous and reproducible cell therapy products.     

Physico-chemical approach to adhesion of Alicyclobacillus cells and spores to model solid materials

Extremophiles - Acidothermophilic bacteria of the genus Alicyclobacillus are frequent contaminants of fruit-based products. This study is the first attempt to characterize the physico-chemical...     

Identification of Peptides Implicated in Antibacterial Activity of Snow Crab Hepatopancreas Hydrolysates by a Bioassay-Guided Fractionation Approach Combined with Mass Spectrometry

Snow crab (Chionoecetes opilio) by-products are a rich source of biomolecules, such as lipids, proteins, and chitin, which have not been extensively investigated. This study aims to identify antibacterial peptides to enhance the value of C. opilio by-products. After hydrolysis of different component parts using Protamex®, and concentration by solid-phase extraction, the resulting fractions were tested for antibacterial activity against Escherichia coli, Listeria innocua, and Vibrio parahaemolyticus. Hepatopancreas was the only tissue to display antibacterial activity detected using this protocol. Four fractions obtained with and without enzymatic hydrolysis of hepatopancreas followed by SPE C18 fractionation and elution with 50 and 80% acetonitrile demonstrated bacteriostatic activity against L. innocua HPB13, from concentrations of 0.30 to 43.05 mg/mL of peptides/proteins. Eleven peptides sharing at least 80% amino acid homology with four antimicrobial peptides were identified by mass spectrometry. Two peptides had homology to crustin-like and yellowfin tuna GAPDH antimicrobial peptides belonging to the marine organisms Penaeus monodon and Thunnus albacares, respectively. Other peptide sequence homologies were also identified: Odorranain-C7 from the frog Odorrana grahami and a predicted antibacterial peptide in the Asian ladybeetle Harmonia axyridis. These active peptides may represent a novel group of bioactive peptides deserving further investigation as food preservatives.