Age-related differences in postural adjustments during limb movement and motor imagery in young and older adults: a kinematic analysis

Motor imagery (MI) shares many of the neurophysiological and behavioural characteristics associated with physical movements, and motor imagery training has been shown to be effective at improving subsequent performance on a given motor task. Jeannerod (2006) proposed that imagined movements are covert internal simulations of the physical counterpart. MI, therefore, provides an ideal setting for studying the anticipatory aspects of posture control. Recent research has shown that systematic postural adjustments occur during periods of MI in young adults, although the timing and direction of these postural adjustments, relative to individual physical actions or imagery of these actions, is not well understood. Additionally, further research has demonstrated that in an older, aged population, MI fails to induce the same postural response seen in their younger counterparts. Older people exhibited relatively restricted postural sway during periods of imagined reaching movements, whereas young adults increased sway whilst performing the same imagined movements. This thesis utilises kinematic measures to study anticipatory and compensatory postural motion in the temporal vicinity of physical and imagined forward arm raises. Healthy young and older adult participants performed, or imagined performing, unilateral and bilateral arm raises under self-initiated and externally triggered conditions. Under bilateral arm raises, when MI was self-initiated, both age groups showed significant forward postural motion during the 1000 ms immediately prior to MI initiation. However, when MI was externally triggered, older participants did not show anticipatory postural motion (APM), whereas this was maintained in the younger participants. When MI of the dominant arm was self-initiated neither age group showed significant APM in the anteroposterior plane. When MI was externally triggered, older participants did not show APM, whereas the younger participants did. Older participants did show movement in the mediolateral direction in both externally and self-initiated conditions indicating sensitivity to the weaker, non-dominant side of the body. Finally, when MI of the non-dominant arm was self-initiated, older participants alone showed forward anteroposterior APM. However, when the same MI movement was externally triggered, there was again no APM observed. Taken together these data demonstrate that MI is accompanied by APM and suggests that older adults are capable of and sensitive to postural motion planning. However, these data show that the use of APM is disrupted when the timing or onset of the task is not under their own control, and as such they may be particularly vulnerable to unpredictable environmental changes such as those that occur in fall situations. Unlike compensatory postural control, which relies on sensory feedback, the anticipatory component of postural control relies on forward motor planning, and as such these findings suggest that forward motor planning is disrupted by a decreasing ability to predict forthcoming events or a decrease in the ability to correctly judge the required postural change for balance. As systematic APM was observed for self-initiated MI, this suggests that MI training may be an effective intervention for anticipatory postural control, strengthening corresponding neural networks and improving the ability to anticipate necessary posture changes. Additionally, these may be used to identify weak postural positions and pre-plan balancing strategies in later age

Concurrent use of prescription drugs and herbal medicinal products in older adults: a systematic review protocol

Background: There has been a global increase in the use of herbal medicinal products (HMPs). About a quarter of UK adults use HMPs, bought over the counter by self-prescription and often not disclosed to healthcare professionals. Potential herb-drug interaction is a clinical concern, with older people at greater risk because of co-morbidities and slower clearance of pharmacologically active compounds. While there is a good understanding of general herbal medicine use by older people, less is known about the extent and implications of concurrent use with prescription medicines. The aim of this systematic review is to assess the prevalence, patterns, safety issues and other factors associated with concurrent prescription and herbal medicines use among older adults. Methods/design: Systematic electronic searches of MEDLINE, PsychINFO, Excerpta Medica dataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine Database (AMED), Web of Science and Cochrane from inception till present for studies reporting the concurrent use of prescription medicines with HMPs in older adults (≥65 years). Lateral searching via related citation (PubMed) and checking reference lists of identified studies will be performed. Two reviewers will independently screen studies, extract data and appraise methodological quality using the Joanna Briggs Institute checklist for prevalence data and the Critical Appraisal Skills Programme (CASP) checklist. Qualitative and quantitative studies from all settings will be included. Non-empirical papers, in vitro experiments and animal studies will be excluded. Primary outcomes are prevalence and patterns of concurrent use, number and types of prescription and HMPs and adverse reactions reported. Secondary outcomes are disclosure of HMP use to healthcare professionals and cost of HMPs. A narrative synthesis of included studies will be performed to summarise the evidence. Discussion: This review will synthesise and critically appraise current knowledge on the concurrent use of drugs and HMPs by older adults and thus provide a better understanding of the issue. It will also identify any gaps in knowledge. By establishing safety issues associated with concurrent use, it will also inform strategies that can help practitioners to identify and manage older people at potential risk of herb-drug interactions. Systematic review registration: PROSPERO CRD4201400909

PTPN11 mutation manifesting as LEOPARD syndrome associated with hypertrophic plexi and neuropathic pain.

BACKGROUND: LEOPARD syndrome (LS) belongs to the family of neuro-cardio-facio-cutaneous syndromes, which include Neurofibromatosis-1 (NF1), Noonan syndrome, Costello Syndrome, cardio-facio-cutaneous syndrome, Noonan-like syndrome with loose anagen hair and Legius syndrome. These conditions are caused by mutations in genes encoding proteins involved in the RAS-MAPK cellular pathway. Clinical heterogeneity and phenotype overlaps across those different syndromes is already recognized. CASE PRESENTATION: We hereby report a heterozygous de novo mutation in the PTPN11 gene (c.1403C > T) manifesting with a clinical picture of LS during childhood, and later development of neuropathic pain with hypertrophic plexi, which are typically observed in NF1 but have not been reported in LS. CONCLUSION: LS caused by PTPN11 mutations may be associated with hypertrophic roots and plexi. Consequently, clinicians should be aware of the possible development of neuropathic pain and consider specific diagnostic work-up and management

Declining and Aging Populations in Rural Japan: A Changing Environment

The purpose of this study is to understand how the environment and well-being of rural Japan will be affected by depopulation and aging populations caused by low birth-rates and migration to urban areas. Rural abandonment will undoubtedly cause changes to local environments and there is a lack of studies in English aimed at understanding the environmental and wellbeing changes happening in Japan due to this change. To study this phenomenon, I designed and distributed a survey to residents of rural Japan designed to measure environmental concern, wellbeing, and perceived change in environment. I also reviewed existing studies from other countries about the effects of rural abandonment and the causes of Japan’s depopulation. I found that, while the effects of rural abandonment are not fully understood, the known negative changes are not beyond mitigation efforts. It is by no means clear cut whether depopulation and urbanization result in net positive or negative changes; this paper adds to the discussion of how to deal with these issues and recommends further discussion about the local versus global implications of changing populations

Towards Learned Emulation of Interannual Water Isotopologue Variations in General Circulation Models

Simulating abundances of stable water isotopologues, i.e. molecules differing in their isotopic composition, within climate models allows for comparisons with proxy data and, thus, for testing hypotheses about past climate and validating climate models under varying climatic conditions. However, many models are run without explicitly simulating water isotopologues. We investigate the possibility to replace the explicit physics-based simulation of oxygen isotopic composition in precipitation using machine learning methods. These methods estimate isotopic composition at each time step for given fields of surface temperature and precipitation amount. We implement convolutional neural networks (CNNs) based on the successful UNet architecture and test whether a spherical network architecture outperforms the naive approach of treating Earth's latitude-longitude grid as a flat image. Conducting a case study on a last millennium run with the iHadCM3 climate model, we find that roughly 40\% of the temporal variance in the isotopic composition is explained by the emulations on interannual and monthly timescale, with spatially varying emulation quality. A modified version of the standard UNet architecture for flat images yields results that are equally good as the predictions by the spherical CNN. We test generalization to last millennium runs of other climate models and find that while the tested deep learning methods yield the best results on iHadCM3 data, the performance drops when predicting on other models and is comparable to simple pixel-wise linear regression. An extended choice of predictor variables and improving the robustness of learned climate--oxygen isotope relationships should be explored in future work

Preconditioning triggered by carbon monoxide (CO) provides neuronal protection following perinatal hypoxia-ischemia

Perinatal hypoxia-ischemia is a major cause of acute mortality in newborns and cognitive and motor impairments in children. Cerebral hypoxia-ischemia leads to excitotoxicity and necrotic and apoptotic cell death, in which mitochondria play a major role. Increased resistance against major damage can be achieved by preconditioning triggered by subtle insults. CO, a toxic molecule that is also generated endogenously, may have a role in preconditioning as low doses can protect against inflammation and apoptosis. In this study, the role of CO-induced preconditioning on neurons was addressed in vitro and in vivo. The effect of 1 h of CO treatment on neuronal death (plasmatic membrane permeabilization and chromatin condensation) and bcl-2 expression was studied in cerebellar granule cells undergoing to glutamate-induced apoptosis. CO's role was studied in vivo in the Rice-Vannucci model of neonatal hypoxia-ischemia (common carotid artery ligature +75 min at 8% oxygen). Apoptotic cells, assessed by Nissl staining were counted with a stereological approach and cleaved caspase 3-positive profiles in the hippocampus were assessed. Apoptotic hallmarks were analyzed in hippocampal extracts by Western Blot. CO inhibited excitotoxicity-induced cell death and increased Bcl-2 mRNA in primary cultures of neurons. In vivo, CO prevented hypoxia-ischemia induced apoptosis in the hippocampus, limited cytochrome c released from mitochondria and reduced activation of caspase-3. Still, Bcl-2 protein levels were higher in hippocampus of CO pre-treated rat pups. Our results show that CO preconditioning elicits a molecular cascade that limits neuronal apoptosis. This could represent an innovative therapeutic strategy for high-risk cerebral hypoxia-ischemia patients, in particular neonates

Stability of sub-surface oxygen at Rh(111)

Using density-functional theory (DFT) we investigate the incorporation of oxygen directly below the Rh(111) surface. We show that oxygen incorporation will only commence after nearly completion of a dense O adlayer (\theta_tot = 1.0 monolayer) with O in the fcc on-surface sites. The experimentally suggested octahedral sub-surface site occupancy, inducing a site-switch of the on-surface species from fcc to hcp sites, is indeed found to be a rather low energy structure. Our results indicate that at even higher coverages oxygen incorporation is followed by oxygen agglomeration in two-dimensional sub-surface islands directly below the first metal layer. Inside these islands, the metastable hcp/octahedral (on-surface/sub-surface) site combination will undergo a barrierless displacement, introducing a stacking fault of the first metal layer with respect to the underlying substrate and leading to a stable fcc/tetrahedral site occupation. We suggest that these elementary steps, namely, oxygen incorporation, aggregation into sub-surface islands and destabilization of the metal surface may be more general and precede the formation of a surface oxide at close-packed late transition metal surfaces.Comment: 9 pages including 9 figure files. Submitted to Phys. Rev. B. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Inequality and violent crime: evidence from data on robbery and violent theft

This article argues that the link between income inequality and violent property crime might be spurious, complementing a similar argument in prior analysis by the author on the determinants of homicide. In contrast, Fajnzylber, Lederman & Loayza (1998; 2002a, b) provide seemingly strong and robust evidence that inequality causes a higher rate of both homicide and robbery/violent theft even after controlling for country-specific fixed effects. Our results suggest that inequality is not a statistically significant determinant, unless either country-specific effects are not controlled for or the sample is artificially restricted to a small number of countries. The reason why the link between inequality and violent property crime might be spurious is that income inequality is likely to be strongly correlated with country-specific fixed effects such as cultural differences. A high degree of inequality might be socially undesirable for any number of reasons, but that it causes violent crime is far from proven

Barriers and enablers to diabetic retinopathy screening attendance: Protocol for a systematic review

BACKGROUND: Diabetic retinopathy is a serious complication of diabetes which, if left untreated, can result in blindness. Population screening among people with diabetes has been shown to be clinically effective; however, suboptimal attendance with wide demographic disparities has been reported. To develop quality improvement interventions to maximise attendance, it is important to understand the theoretical determinants (i.e. barriers and enablers) of screening behaviour. The aim of this systematic review is to identify and synthesise the modifiable barriers and enablers associated with diabetic retinopathy screening attendance. METHODS/DESIGN: Primary and secondary studies will be included if they report perceived barriers/enablers of diabetic retinopathy screening attendance, from the perspectives of people with diabetes and healthcare providers. There will be no restrictions on study design. Studies will be identified from published and grey literature through multiple sources. Bibliographic databases will be searched using synonyms in four search domains: diabetic retinopathy; screening; barriers/enablers; and theoretical constructs relating to behaviour. Search engines and established databases of grey literature will be searched to identify additional relevant studies. Extracted data will include: participant quotations from qualitative studies, statistical analyses from questionnaire and survey studies, and interpretive descriptions and summaries of results from reports. All extracted data will be coded into domains from the Theoretical Domains Framework (TDF) and (for organisational level data) the Consolidated Framework of Implementation Research (CFIR); with domains representing theoretical barriers/enablers proposed to mediate behaviour change. The potential role of each domain in influencing retinopathy screening attendance will be investigated through thematic analysis of the TDF/ CFIR coding. Domain importance will be identified using pre-specified criteria: "frequency" and "expressed importance". Variations in perceived barriers and enablers between demographic groups (e.g., socio-economic, ethnic) will be explored. DISCUSSION: This review will identify important barriers and enablers likely to influence attendance for diabetic retinopathy screening. The results will be used to assess the extent to which existing interventions targeting attendance address the theoretical determinants of attendance behaviour. Findings will inform recommendations for future intervention design. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016032990