Frailty and nutrition.

As the ageing population grows and forms a significant category of over 65s in many societies, along with it comes the risk of developing physical and psychological degenerative changes. This presents many challenges for health and social care services in not only identifying those at risk but also managing that risk to try to preserve health and independence for as long as possible. Screening for frailty has supported services to identify those that may be at risk of hospitalisation, requiring long term care or support services at home in older age. Frailty can be exacerbated by the risk of nutritional deficiencies and more severe malnutrition. Therefore, screening for frailty should also include a nutritional assessment, which can be supported by a recognition of the need for nutritional support along with other holistic frailty management.

B 1 + $$ {\mathrm{B}}_1

PURPOSE: Nuclear Overhauser effect magnetization transfer ratio (NOEMTR ) is a technique used to investigate brain lipids and macromolecules in greater detail than other techniques and benefits from increased contrast at 7 T. However, this contrast can become degraded because of B 1 + $$ {\mathrm{B}}_1^{+} $$ inhomogeneities present at ultra-high field strengths. High-permittivity dielectric pads (DP) have been used to correct for these inhomogeneities via displacement currents generating secondary magnetic fields. The purpose of this work is to demonstrate that dielectric pads can be used to mitigate B 1 + $$ {\mathrm{B}}_1^{+} $$ inhomogeneities and improve NOEMTR contrast in the temporal lobes at 7 T. METHODS: Partial 3D NOEMTR contrast images and whole brain B 1 + $$ {\mathrm{B}}_1^{+} $$ field maps were acquired on a 7 T MRI across six healthy subjects. Calcium titanate DP, having a relative permittivity of 110, was placed next to the subject's head near the temporal lobes. Pad corrected NOEMTR images had a separate postprocessing linear correction applied. RESULTS: DP provided supplemental B 1 + $$ {\mathrm{B}}_1^{+} $$ to the temporal lobes while also reducing the B 1 + $$ {\mathrm{B}}_1^{+} $$ magnitude across the posterior and superior regions of the brain. This resulted in a statistically significant increase in NOEMTR contrast in substructures of the temporal lobes both with and without linear correction. The padding also produced a convergence in NOEMTR contrast toward approximately equal mean values. CONCLUSION: NOEMTR images showed significant improvement in temporal lobe contrast when DP were used, which resulted from an increase in B 1 + $$ {\mathrm{B}}_1^{+} $$ homogeneity across the entire brain slab. DP-derived improvements in NOEMTR are expected to increase the robustness of the brain substructural measures both in healthy and pathological conditions.

Manipulating the Valence of Future Thought: The Effect on Affect.

Imagining personal future events is associated with well-being, but the nature and direction of this relationship are unclear. This study investigated whether imagining episodic future scenarios, experimentally manipulated for valence, have an immediate impact on affect. University students (N = 197) completed a 2 × 3 between-subject online study in which they imagined four personal events likely to occur in the future. Participants were directed to imagine positive or negative events or were undirected as to valence to additionally assess the valence and effect of self-directed imagined scenarios. Participants in all three conditions reported a change in positive affect immediately after the task, with both positive and nondirected thinking improving positive affect and negative future thoughts reducing it. However, negative affect only shifted in response to negative future thinking but not the other conditions. These findings demonstrate that there is an immediate causal effect of episodic future thinking on affect but only in specific directions and that this differs from the patterns shown in longer term measurements. The findings also suggest when self-directed that imagined future thoughts tend to mirror the valence and causal effect of positively induced thoughts. This study has implications for the ongoing debate around future thinking and well-being.

A Comprehensive Optogenetic Pharmacology Toolkit for In Vivo Control of GABA(A) Receptors and Synaptic Inhibition.

Exogenously expressed opsins are valuable tools for optogenetic control of neurons in circuits. A deeper understanding of neural function can be gained by bringing control to endogenous neurotransmitter receptors that mediate synaptic transmission. Here we introduce a comprehensive optogenetic toolkit for controlling GABA(A) receptor-mediated inhibition in the brain. We developed a series of photoswitch ligands and the complementary genetically modified GABA(A) receptor subunits. By conjugating the two components, we generated light-sensitive versions of the entire GABA(A) receptor family. We validated these light-sensitive receptors for applications across a broad range of spatial scales, from subcellular receptor mapping to in vivo photo-control of visual responses in the cerebral cortex. Finally, we generated a knockin mouse in which the "photoswitch-ready" version of a GABA(A) receptor subunit genomically replaces its wild-type counterpart, ensuring normal receptor expression. This optogenetic pharmacology toolkit allows scalable interrogation of endogenous GABA(A) receptor function with high spatial, temporal, and biochemical precision.

Pathogenesis-related protein expression in the apoplast of wheat leaves protected against leaf rust following application of plant extracts.

Leaf rust (Puccinia triticina) is a major disease of wheat. We tested aqueous leaf extracts of Jacaranda mimosifolia (Bignoniaceae), Thevetia peruviana (Apocynaceae), and Calotropis procera (Apocynaceae) for their ability to protect wheat from leaf rust. Extracts from all three species inhibited P. triticina urediniospore germination in vitro. Plants sprayed with extracts before inoculation developed significantly lower levels of disease incidence (number of plants infected) than unsprayed, inoculated controls. Sprays combining 0.6% leaf extracts and 2 mM salicylic acid with the fungicide Amistar Xtra at 0.05% (azoxystrobin at 10 µg/liter + cyproconazole at 4 µg/liter) reduced disease incidence significantly more effectively than sprays of fungicide at 0.1% alone. Extracts of J. mimosifolia were most active, either alone (1.2%) or in lower doses (0.6%) in combination with 0.05% Amistar Xtra. Leaf extracts combined with fungicide strongly stimulated defense-related gene expression and the subsequent accumulation of pathogenesis-related (PR) proteins in the apoplast of inoculated wheat leaves. The level of protection afforded was significantly correlated with the ability of extracts to increase PR protein expression. We conclude that pretreatment of wheat leaves with spray formulations containing previously untested plant leaf extracts enhances protection against leaf rust provided by fungicide sprays, offering an alternative disease management strategy.

Depression and its relation to light deprivation.

The absence or diminution of light is potentially an anxiety-arousing situation for, perhaps, all of us. Even a cursory look at the origin myths of many cultures reveals the chaotic, destructive, and dangerous aspects of darkness. Additionally, language reflects the same qualities metaphorically and symbolically. Developmentally, the arrival of the darkness of evening potentially signals object loss and ego regression. But factors other than ubiquitous references to a consideration of light and darkness are relevant. Can it be that we are all at least prone to depression due in part to this factor? Questions regarding possible biological causes of depression are perhaps unanswerable at this time. Is the seratonin level really associated with depression and light deprivation? Research is as yet inconclusive. If a relationship exists, another question must be asked: Will certain psychological situations affect a person's seratonin production? The answer to this question of how depression is associated with biological causes is certainly beyond the scope of this paper. Yet the preceding case history reveals at least some psychological causes of depression that were initially seen as biologically based. The SAD proponents would have treated Mr. B with light therapy. The quick solution of light therapy, based on a shaky theoretical base and lacking sturdy research, has too often replaced the psychoanalytic approach. In all too many situations psychoanalysts are being replaced by lightbulbs.