Evaluating the use of seaweed extracts against root knot nematodes: A meta-analytic approach.

Plant parasitic nematode (PPN) control has historically relied on the use of synthetic chemical nematicides, however many are toxic to both human health and the environment. The withdrawal of the more harmful nematicides coupled with increases in soil temperatures and increased occurrence of pests and diseases associated with climate change, may enable PPN to increase in numbers and spread globally. The need for sustainable and environmentally friendly management options is necessary while facing future food security scares in order to feed the ever-growing population. Seaweed extracts have been used for decades in agriculture and horticulture as soil biostimulants, however there is a growing body of evidence to suggest that they could be used to reduce the occurrence of damaging PPN infections. Using meta-analysis, we investigated whether seaweed extracts applied to soil could reduce root knot nematode (RKN) abundance and whether there could be confounding factors that influence their efficacy. We found that seaweed extracts reduce RKN performance and that various factors affected the efficacy of seaweed, including the seaweed species itself and the crop the seaweed was applied to. Ascophyllum nodosum extracts were found to be the most effective. Particular RKN species were more sensitive than others to seaweed species used and, in some cases, specific seaweed species only affected particular RKN species. Different life cycle stages were also differentially susceptible to seaweed application, where both egg hatching and population abundance could be reduced via seaweed use. This research indicates that seaweed extracts could potentially be used to help reduce RKN attack on plants.

Meningioma and mood: exploring the potential for meningioma to affect psychological distress before and after surgical removal.

Background: Much of the research exploring psychological distress with meningioma stem from studies including several brain tumour types (including malignant tumours) meaning that focus on meningioma is limited and that conclusions are based on small samples. Moreover, contradictory findings have been reported regarding the effects of meningioma on mood. Here, the authors present a study exploring pre and post mood scores in meningioma only patients using a sample size larger than any previous research attempt. Method: The Hospital Anxiety and Depression Scale (HADS) was used as an objective measure of mood in a clinical sample of 184 UK patients pre and post meningioma removal surgery. Repeated measures designs were used to assess for significant differences in depression and anxiety scores before and after surgery, chi-squared analyses were used to establish for clinically significant change. Results: The study revealed a significant decrease, and a medium effect size, in mean depression scores after surgery to remove the meningioma (p = .002, g = 0.35). However, no significant effect was found following meningioma removal and anxiety scores (p = .113, g = 0.17). Discussion: No significant effects were determined between mood and meningioma location. A discussion of the findings, and potential implications, is presented.

What paint can tell us: A fractal analysis of neurological changes in seven artists.

OBJECTIVE: The notion that artistic capability increases with dementia is both novel and largely unsupported by available literature. Recent research has suggested an emergence of artistic capabilities to be a by-product of involuntary behaviour seen with dementia, as opposed to a progression in original thinking (de Souza, et al., 2010). A far more complementary explanation comes from Hannemann (2006), who suggests that art offers an outlet for dementia patients to refine and sharpen their cognitive abilities. As dementia severely impedes linguistic skills, non-verbal therapeutic methods such as painting can permit dementia patients to express themselves in a way not possible verbally. Fractal analysis has been used to determine the authenticity of major works of art. Taylor et al., (1999) found that through a fractal analysis of Jackson Pollock's paintings it was possible to distinguish authentic works from a large collection of fakes, demonstrating that when artists paint they instill within their work their own pattern of unique fractal behaviour. Can age-indexed variations in the fractal dimension of the works of artists anticipate specific cognitive deteriorations? METHOD: To answer this question we analysed age-related variations in the fractal dimension of a large corpus of digital images (n = 2092) of work created by seven notable artists who experienced both normal ageing and neurodegenerative disorders. RESULTS: The results of our analysis showed that patterns of change in the fractal dimension of the paintings differentiated artists who suffered neurological deterioration from those of normal aging controls. CONCLUSIONS: These findings are of importance for two reasons. Our work adds to studies that demonstrate that fractal analysis has the potential to determine the provenance of paintings. Secondly, our work suggests that may be possible to identify a-typical changes in the structure of an artist's work; changes that may be early indicators of the onset of neurological deterioration. (PsycINFO Database Record

Co-Receptor CD8-Mediated Modulation of T-Cell Receptor Functional Sensitivity and Epitope Recognition Degeneracy.

The interaction between T-cell receptors (TCRs) and peptide epitopes is highly degenerate: a TCR is capable of interacting productively with a wide range of different peptide ligands, involving not only cross-reactivity proper (similar epitopes elicit strong responses), but also polyspecificity (ligands with distinct physicochemical properties are capable of interacting with the TCR). Degeneracy does not gainsay the fact that TCR recognition is fundamentally specific: for the vast majority of ligands, the functional sensitivity of a given TCR is virtually null whereas this TCR has an appreciable functional sensitivity only for a minute fraction of all possible ligands. Degeneracy can be described mathematically as the probability that the functional sensitivity, of a given TCR to a randomly selected ligand, exceeds a set value. Variation of this value generates a statistical distribution that characterizes TCR degeneracy. This distribution can be modeled on the basis of a Gaussian distribution for the TCR/ligand dissociation energy. The kinetics of the TCR and the MHCI molecule can be used to transform this underlying Gaussian distribution into the observed distribution of functional sensitivity values. In the present paper, the model is extended by accounting explicitly for the kinetics of the interaction between the co-receptor and the MHCI molecule. We show that T-cells can modulate the level of degeneracy by varying the density of co-receptors on the cell surface. This could allow for an analog of avidity maturation during incipient T-cell responses.

Peptide length determines the outcome of TCR/peptide-MHCI engagement.

αß-TCRs expressed at the CD8(+) T-cell surface interact with short peptide fragments (p) bound to MHC class I molecules (pMHCI). The TCR/pMHCI interaction is pivotal in all aspects of CD8(+) T-cell immunity. However, the rules that govern the outcome of TCR/pMHCI engagement are not entirely understood, and this is a major barrier to understanding the requirements for both effective immunity and vaccination. In the present study, we discovered an unexpected feature of the TCR/pMHCI interaction by showing that any given TCR exhibits an explicit preference for a single MHCI-peptide length. Agonists of nonpreferred length were extremely rare, suboptimal, and often entirely distinct in sequence. Structural analysis indicated that alterations in peptide length have a major impact on antigenic complexity, to which individual TCRs are unable to adapt. This novel finding demonstrates that the outcome of TCR/pMHCI engagement is determined by peptide length in addition to the sequence identity of the MHCI-bound peptide. Accordingly, the effective recognition of pMHCI Ag, which is a prerequisite for successful CD8(+) T-cell immunity and protective vaccination, can only be achieved by length-matched Ag-specific CD8(+) T-cell clonotypes.

Anti-CD8 antibodies can trigger CD8+ T cell effector function in the absence of TCR engagement and improve peptide-MHCI tetramer staining.

CD8(+) T cells recognize immunogenic peptides presented at the cell surface bound to MHCI molecules. Ag recognition involves the binding of both TCR and CD8 coreceptor to the same peptide-MHCI (pMHCI) ligand. Specificity is determined by the TCR, whereas CD8 mediates effects on Ag sensitivity. Anti-CD8 Abs have been used extensively to examine the role of CD8 in CD8(+) T cell activation. However, as previous studies have yielded conflicting results, it is unclear from the literature whether anti-CD8 Abs per se are capable of inducing effector function. In this article, we report on the ability of seven monoclonal anti-human CD8 Abs to activate six human CD8(+) T cell clones with a total of five different specificities. Six of seven anti-human CD8 Abs tested did not activate CD8(+) T cells. In contrast, one anti-human CD8 Ab, OKT8, induced effector function in all CD8(+) T cells examined. Moreover, OKT8 was found to enhance TCR/pMHCI on-rates and, as a consequence, could be used to improve pMHCI tetramer staining and the visualization of Ag-specific CD8(+) T cells. The anti-mouse CD8 Abs, CT-CD8a and CT-CD8b, also activated CD8(+) T cells despite opposing effects on pMHCI tetramer staining. The observed heterogeneity in the ability of anti-CD8 Abs to trigger T cell effector function provides an explanation for the apparent incongruity observed in previous studies and should be taken into consideration when interpreting results generated with these reagents. Furthermore, the ability of Ab-mediated CD8 engagement to deliver an activation signal underscores the importance of CD8 in CD8(+) T cell signaling.