Phonons in potassium doped graphene: the effects of electron-phonon interactions, dimensionality and ad-atom ordering

Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene doped via the field-effect. At high dopings, beyond those accessible by the field-effect, the G-peak strongly softens and broadens. This is interpreted as a dynamic, non-adiabatic renormalization of the phonon self-energy. At dopings between the light and heavily doped regimes, we find a robust inhomogeneous phase where the potassium coverage is segregated into regions of high and low density. The phonon energies, linewidths and tunability are remarkably similar for 1-4 layer graphene, but significantly different to doped bulk graphite.Comment: Accepted in Phys. Rev. B as a Rapid Communication. 5 pages, 3 figures, revised text with additional dat

Generation of internal stress and its effects

Internal stresses may be generated continually in many polycrystalline materials. Their existence is manifested by changes in crystal defect concentration and arrangement, by surface observations, by macroscopic shape changes and particularly by alteration of mechanical properties when external stresses are simultaneously imposed

A systematic review and meta-analysis of the long-term effects of physical activity interventions on objectively measured outcomes

Abstract Background Although physical activity interventions are frequently reported to be effective, long-term changes are needed to generate meaningful health benefits. There are criticisms that evaluations of physical activity interventions mostly report short-term outcomes and that these are often self-reported rather than measured objectively. This study therefore aimed to assess the long-term (at least 24 month) effectiveness of behavioural interventions on objectively measured physical activity. Methods We conducted a systematic review with a meta-analysis of effects on objectively measured physical activity. We searched: Cochrane CENTRAL, EMBASE, PsychInfo, CINAHL and Pubmed up to 10th January 2022. Studies were included if they were in English and included a physical intervention that assessed physical activity in the long-term (defined as at least 24 months). Results Eight studies with 8480 participants were identified with data suitable for meta-analysis. There was a significant effect of interventions on daily steps 24 months post baseline (four studies, SMD: 0.15, 95% CI: 0.02 to 0.28) with similar results at 36 to 48 months of follow up (four studies, SMD: 0.17, 95% CI: 0.07 to 0.27). There was a significant effect of interventions on moderate-to-vigorous physical activity 24 months post baseline (four studies, SMD: 0.18 95% CI: 0.07 to 0.29) and at 36 to 48 months (three studies, SMD: 0.16 95% CI: 0.09 to 0.23). The mean effect size was small. However, the changes in moderate-to-vigorous physical activity and steps per day were clinically meaningful in the best-performing studies. Conclusion This review suggests that behavioural interventions can be effective in promoting small, but clinically meaningful increases in objectively measured physical activity for up to 48 months. There is therefore a need to develop interventions that can achieve greater increases in long-term physical activity with greater efficiency

Development of a risk assessment tool to assess the significance of septic tanks around freshwater SSSIs. Phase 1 – Understanding better the retention of phosphorus in the drainage fields

The findings contained within this report have allowed Natural England to refine and implement a risk assessment methodology for septic tanks, which was developed through a previous project with CEH (NECR170)

ExoMars entry, descent and landing science

The entry, descent and landing of ExoMars offer a rare (once-per-mission) opportunity to perform in situ investigation of the martian environment over a wide altitude range. Entry, Descent and Landing System (EDLS) measurements can provide essential data for atmospheric scientific investigations. We intend to perform atmospheric science measurements by exploiting data from EDLS engineering sensors and exploiting their readings beyond the expected engineering information

3D Bioelectronic Model of the Human Intestine

Organ on chip (OoC) technologies have the potential to improve the translation of promising therapies currently failing in clinical trials at great expense and time due to dissimilarities between animal and human biology. Successful OoC models integrate human cells within 3D tissues with surrounding biomolecular components, and have benefited from the use of inert 3D gels and scaffolds used as templates, prompting tissue formation. However, monitoring technologies used to assess tissue integrity and drug effects are ill adapted to 3D biology. Here, a tubular electroactive scaffold serves as a template for a 3D human intestine, and enables dynamic electrical monitoring of tissue formation over 1 month. Cell- and extracellular matrix component-invoked changes in the properties of the scaffold alleviate the need for posthoc placement of invasive metallic electrodes or downstream analyses. Formation of in vivo-like stratified and polarized intestinal tissue compete with lumen contrasts with other quasi3D models of the intestine using rigid porous membrane to separate cell types. These results provide unprecedented real-time information on tissue formation with highly sensitive multimodal operation, thanks to dual electrode and transistor operation. This device and the methodology for tissue growth within it represents a paradigm shift for disease modeling and drug discover

The role of insulin receptor substrate 2 in hypothalamic and β cell function

Insulin receptor substrate 2 (Irs2) plays complex roles in energy homeostasis. We generated mice lacking Irs2 in β cells and a population of hypothalamic neurons (RIPCreIrs2KO), in all neurons (NesCreIrs2KO), and in proopiomelanocortin neurons (POMCCreIrs2KO) to determine the role of Irs2 in the CNS and β cell. RIPCreIrs2KO mice displayed impaired glucose tolerance and reduced β cell mass. Overt diabetes did not ensue, because β cells escaping Cre-mediated recombination progressively populated islets. RIPCreIrs2KO and NesCreIrs2KO mice displayed hyperphagia, obesity, and increased body length, which suggests altered melanocortin action. POMCCreIrs2KO mice did not display this phenotype. RIPCreIrs2KO and NesCreIrs2KO mice retained leptin sensitivity, which suggests that CNS Irs2 pathways are not required for leptin action. NesCreIrs2KO and POMCCreIrs2KO mice did not display reduced β cell mass, but NesCreIrs2KO mice displayed mild abnormalities of glucose homeostasis. RIPCre neurons did not express POMC or neuropeptide Y. Insulin and a melanocortin agonist depolarized RIPCre neurons, whereas leptin was ineffective. Insulin hyperpolarized and leptin depolarized POMC neurons. Our findings demonstrate a critical role for IRS2 in β cell and hypothalamic function and provide insights into the role of RIPCre neurons, a distinct hypothalamic neuronal population, in growth and energy homeostasis