Depth-Resolved Magnetization Dynamics Revealed by X-Ray Reflectometry Ferromagnetic Resonance.

Magnetic multilayers offer diverse opportunities for the development of ultrafast functional devices through advanced interface and layer engineering. Nevertheless, a method for determining their dynamic properties as a function of depth throughout such stacks has remained elusive. By probing the ferromagnetic resonance modes with element-selective soft x-ray resonant reflectivity, we gain access to the magnetization dynamics as a function of depth. Most notably, using reflectometry ferromagnetic resonance, we find a phase lag between the coupled ferromagnetic layers in [CoFeB/MgO/Ta]_{4} multilayers that is invisible to other techniques. The use of reflectometry ferromagnetic resonance enables the time-resolved and depth-resolved probing of the complex magnetization dynamics of a wide range of functional magnetic heterostructures with absorption edges in the soft x-ray wavelength regime.

Prevalence and duration of non-motor symptoms in prodromal Parkinson's disease.

BACKGROUND AND PURPOSE: The prevalence and duration of non-motor symptoms (NMS) in prodromal Parkinson's disease (PD) has not been extensively studied. The aim of this study was to determine the prevalence and duration of prodromal NMS (pNMS) in a cohort of patients with recently diagnosed PD. METHODS: We evaluated the prevalence and duration of pNMS in patients with early PD (n = 154). NMS were screened for using the Non-Motor Symptom Questionnaire (NMSQuest). We subtracted the duration of the presence of each individual NMS reported from the duration of the earliest motor symptom. NMS whose duration preceded the duration of motor symptoms were considered a pNMS. Individual pNMS were then grouped into relevant pNMS clusters based on the NMSQuest domains. Motor subtypes were defined as tremor dominant, postural instability gait difficulty (PIGD) and indeterminate type according to the Movement Disorder Society Unified Parkinson's Disease Rating Scale revision. RESULTS: Prodromal NMS were experienced by 90.3% of patients with PD and the median number experienced was 4 (interquartile range, 2-7). A gender difference existed in the pNMS experienced, with males reporting more sexual dysfunction, forgetfulness and dream re-enactment, whereas females reported more unexplained weight change and anxiety. There was a significant association between any prodromal gastrointestinal symptoms [odds ratio (OR), 2.30; 95% confidence interval (CI), 1.08-4.89, P = 0.03] and urinary symptoms (OR, 2.54; 95% CI, 1.19-5.35, P = 0.016) and the PIGD phenotype. Further analysis revealed that total pNMS were not significantly associated with the PIGD phenotype (OR, 1.10; 95% CI, 0.99-1.21, P = 0.068). CONCLUSIONS: Prodromal NMS are common and a gender difference in pNMS experienced in prodromal PD may exist. The PIGD phenotype had a higher prevalence of prodromal gastrointestinal and urinary tract symptoms.

Cerebral glucose metabolism and cognition in newly diagnosed Parkinson's disease: ICICLE-PD study.

OBJECTIVE: To assess reductions of cerebral glucose metabolism in Parkinson's disease (PD) with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), and their associations with cognitive decline. METHODS: FDG-PET was performed on a cohort of 79 patients with newly diagnosed PD (mean disease duration 8 months) and 20 unrelated controls. PD participants were scanned while on their usual dopaminergic medication. Cognitive testing was performed at baseline, and after 18 months using the Cognitive Drug Research (CDR) and Cambridge Neuropsychological Test Automated Battery (CANTAB) computerised batteries, the Mini-Mental State Examination (MMSE), and the Montreal Cognitive Assessment (MoCA). We used statistical parametric mapping (SPM V.12) software to compare groups and investigate voxelwise correlations between FDG metabolism and cognitive score at baseline. Linear regression was used to evaluate how levels of cortical FDG metabolism were predictive of subsequent cognitive decline rated with the MMSE and MoCA. RESULTS: PD participants showed reduced glucose metabolism in the occipital and inferior parietal lobes relative to controls. Low performance on memory-based tasks was associated with reduced FDG metabolism in posterior parietal and temporal regions, while attentional performance was associated with more frontal deficits. Baseline parietal to cerebellum FDG metabolism ratios predicted MMSE (ß=0.38, p=0.001) and MoCA (ß=0.3, p=0.002) at 18 months controlling for baseline score. CONCLUSIONS: Reductions in cortical FDG metabolism were present in newly diagnosed PD, and correlated with performance on neuropsychological tests. A reduced baseline parietal metabolism is associated with risk of cognitive decline and may represent a potential biomarker for this state and the development of PD dementia.

Past, present, and future of Parkinson's disease: A special essay on the 200th Anniversary of the Shaking Palsy.

This article reviews and summarizes 200 years of Parkinson's disease. It comprises a relevant history of Dr. James Parkinson's himself and what he described accurately and what he missed from today's perspective. Parkinson's disease today is understood as a multietiological condition with uncertain etiopathogenesis. Many advances have occurred regarding pathophysiology and symptomatic treatments, but critically important issues are still pending resolution. Among the latter, the need to modify disease progression is undoubtedly a priority. In sum, this multiple-author article, prepared to commemorate the bicentenary of the shaking palsy, provides a historical state-of-the-art account of what has been achieved, the current situation, and how to progress toward resolving Parkinson's disease. © 2017 International Parkinson and Movement Disorder Society.

Cognitive impairment in Parkinson's disease: impact on quality of life of carers.

BACKGROUND: The quality of life (QoL) of informal caregivers of people with Parkinson's disease (PD) (PwP) can be affected by the caring role. Because of cognitive symptoms and diminished activities of daily living, in addition to the management of motor symptoms, carers of PwP and cognitive impairment may experience increased levels of burden and poorer QoL compared with carers of PwP without cognitive impairment. This study aimed to investigate the impact of cognitive impairment in PD upon QoL of carers. METHODS: Approximately 36 months after diagnosis, 66 dyadic couples of PwP and carers completed assessments. PwP completed a schedule of neuropsychological assessments and QoL measures; carers of PwP completed demographic questionnaires and assessments of QoL. Factor scores of attention, memory/executive function and global cognition, as derived by principal component analysis, were used to evaluate cognitive domains. RESULTS: Hierarchical regression analysis found lower Montreal Cognitive Assessment was a significant independent predictor of poorer carer QoL, in addition to number of hours spent caregiving, carer depression and PD motor severity. Attentional deficits accounted for the largest proportion of variance of carer QoL. Carers of PwP and dementia (n = 9) had significantly poorer QoL scores compared with PwP and mild cognitive impairment (n = 18) or normal cognition (n = 39) carers (p < 0.01). CONCLUSIONS: Attentional deficits were the strongest predictor of carer QoL compared with other cognitive predictors. Carers for those with PD dementia reported the poorest QoL. Interventions such as respite or cognitive behavioural therapy to improve mood and self-efficacy in carers may improve carer QoL. © 2016 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons, Ltd.

Multidomain Skyrmion Lattice State in Cu2OSeO3.

Magnetic skyrmions in chiral magnets are nanoscale, topologically protected magnetization swirls that are promising candidates for spintronics memory carriers. Therefore, observing and manipulating the skyrmion state on the surface level of the materials are of great importance for future applications. Here, we report a controlled way of creating a multidomain skyrmion state near the surface of a Cu2OSeO3 single crystal, observed by soft resonant elastic X-ray scattering. This technique is an ideal tool to probe the magnetic order at the L3 edge of 3d metal compounds giving an average depth sensitivity of ∼50 nm. The single-domain 6-fold-symmetric skyrmion lattice can be broken up into domains, overcoming the propagation directions imposed by the cubic anisotropy by applying the magnetic field in directions deviating from the major cubic axes. Our findings open the door to a new way to manipulate and engineer the skyrmion state locally on the surface or on the level of individual skyrmions, which will enable applications in the future.

Anxiety and anxious-depression in Parkinson's disease over a 4-year period: a latent transition analysis.

BACKGROUND: Depression and anxiety in Parkinson's disease are common and frequently co-morbid, with significant impact on health outcome. Nevertheless, management is complex and often suboptimal. The existence of clinical subtypes would support stratified approaches in both research and treatment. METHOD: Five hundred and thirteen patients with Parkinson's disease were assessed annually for up to 4 years. Latent transition analysis (LTA) was used to identify classes that may conform to clinically meaningful subgroups, transitions between those classes over time, and baseline clinical and demographic features that predict common trajectories. RESULTS: In total, 64.1% of the sample remained in the study at year 4. LTA identified four classes, a 'Psychologically healthy' class (approximately 50%), and three classes associated with psychological distress: one with moderate anxiety alone (approximately 20%), and two with moderate levels of depression plus moderate or severe anxiety. Class membership tended to be stable across years, with only about 15% of individuals transitioning between the healthy class and one of the distress classes. Stable distress was predicted by higher baseline depression and psychiatric history and younger age of onset of Parkinson's disease. Those with younger age of onset were also more likely to become distressed over the course of the study. CONCLUSIONS: Psychopathology was characterized by relatively stable anxiety or anxious-depression over the 4-year period. Anxiety, with or without depression, appears to be the prominent psychopathological phenotype in Parkinson's disease suggesting a pressing need to understanding its mechanisms and improve management.

Olfaction in Parkin single and compound heterozygotes in a cohort of young onset Parkinson's disease patients.

BACKGROUND: Parkin related Parkinson's disease (PD) is differentiated from idiopathic PD by absent or sparse Lewy bodies, and preserved olfaction. The significance of single Parkin mutations in the pathogenesis of PD is debated. OBJECTIVES: To assess olfaction results according to Parkin mutation status. To compare the prevalence of Parkin single heterozygous mutations in patients diagnosed with PD to the rate in healthy controls in order to establish whether these single mutations could be a risk factor for developing PD. METHODS: Parkin gene mutation testing was performed in young onset PD (diagnosed <50 years old) to identify three groups: Parkin homozygous or compound heterozygote mutation carriers, Parkin single heterozygote mutation carriers, and non-carriers of Parkin mutations. Olfaction was tested using the 40-item British version of the University of Pennsylvania smell identification test (UPSIT). RESULTS: Of 344 young onset PD cases tested, 8 (2.3%) were Parkin compound heterozygotes and 13 (3.8%) were Parkin single heterozygotes. Olfaction results were available in 282 cases (eight compound heterozygotes, nine single heterozygotes, and 265 non-carriers). In Parkin compound heterozygotes, the median UPSIT score was 33, interquartile range (IQR) 28.5-36.5, which was significantly better than in single Parkin heterozygotes (median 19, IQR 18-28) and non-carriers (median score 22, IQR 16-28) (ANOVA P < 0.001). These differences persisted after adjusting for age, disease duration, gender, and smoking (P < 0.001). There was no significant difference in UPSIT scores between single heterozygotes and non-carriers (P = 0.90). CONCLUSIONS: Patients with Parkin compound heterozygous mutations have relatively preserved olfaction compared to Parkin single heterozygotes and non-carriers. The prevalence of Parkin single heterozygosity is similar to the 3.7% rate reported in healthy controls.

Summary of the recommendations of the EFNS/MDS-ES review on therapeutic management of Parkinson's disease.

OBJECTIVE: To summarize the 2010 EFNS/MDS-ES evidence-based treatment recommendations for the management of Parkinson's disease (PD). This summary includes the treatment recommendations for early and late PD. METHODS: For the 2010 publication, a literature search was undertaken for articles published up to September 2009. For this summary, an additional literature search was undertaken up to December 2010. Classification of scientific evidence and the rating of recommendations were made according to the EFNS guidance. In cases where there was insufficient scientific evidence, a consensus statement ('good practice point') is made. RESULTS AND CONCLUSIONS: For each clinical indication, a list of therapeutic interventions is provided, including classification of evidence.

EFNS/MDS-ES/ENS [corrected] recommendations for the diagnosis of Parkinson's disease.

BACKGROUND: A Task Force was convened by the EFNS/MDS-ES Scientist Panel on Parkinson's disease (PD) and other movement disorders to systemically review relevant publications on the diagnosis of PD. METHODS: Following the EFNS instruction for the preparation of neurological diagnostic guidelines, recommendation levels have been generated for diagnostic criteria and investigations. RESULTS: For the clinical diagnosis, we recommend the use of the Queen Square Brain Bank criteria (Level B). Genetic testing for specific mutations is recommended on an individual basis (Level B), taking into account specific features (i.e. family history and age of onset). We recommend olfactory testing to differentiate PD from other parkinsonian disorders including recessive forms (Level A). Screening for pre-motor PD with olfactory testing requires additional tests due to limited specificity. Drug challenge tests are not recommended for the diagnosis in de novo parkinsonian patients. There is an insufficient evidence to support their role in the differential diagnosis between PD and other parkinsonian syndromes. We recommend an assessment of cognition and a screening for REM sleep behaviour disorder, psychotic manifestations and severe depression in the initial evaluation of suspected PD cases (Level A). Transcranial sonography is recommended for the differentiation of PD from atypical and secondary parkinsonian disorders (Level A), for the early diagnosis of PD and in the detection of subjects at risk for PD (Level A), although the technique is so far not universally used and requires some expertise. Because specificity of TCS for the development of PD is limited, TCS should be used in conjunction with other screening tests. Conventional magnetic resonance imaging and diffusion-weighted imaging at 1.5 T are recommended as neuroimaging tools that can support a diagnosis of multiple system atrophy (MSA) or progressive supranuclear palsy versus PD on the basis of regional atrophy and signal change as well as diffusivity patterns (Level A). DaTscan SPECT is registered in Europe and the United States for the differential diagnosis between degenerative parkinsonisms and essential tremor (Level A). More specifically, DaTscan is indicated in the presence of significant diagnostic uncertainty such as parkinsonism associated with neuroleptic exposure and atypical tremor manifestations such as isolated unilateral postural tremor. Studies of [(123) I]MIBG/SPECT cardiac uptake may be used to identify patients with PD versus controls and MSA patients (Level A). All other SPECT imaging studies do not fulfil registration standards and cannot be recommended for routine clinical use. At the moment, no conclusion can be drawn as to diagnostic efficacy of autonomic function tests, neurophysiological tests and positron emission tomography imaging in PD. CONCLUSIONS: The diagnosis of PD is still largely based on the correct identification of its clinical features. Selected investigations (genetic, olfactory, and neuroimaging studies) have an ancillary role in confirming the diagnosis, and some of them could be possibly used in the near future to identify subjects in a pre-symptomatic phase of the disease.

Frequency, prevalence, incidence and risk factors associated with visual hallucinations in a sample of patients with Parkinson's disease: a longitudinal 4-year study.

OBJECTIVE: To examine the prevalence, incidence and risk factors associated with visual hallucinations (VHs) amongst people suffering from Parkinson's disease (PD). METHODS: We recruited 513 patients with PD from movement disorder and PD clinics within three sites in the UK. Patients were interviewed using a series of standardised clinical rating scales at baseline, 12, 24 and 36 months. Data relating to VHs were collected using the North-East Visual Hallucinations Interview. Prevalence rates for VHs at each assessment were recorded. Associations were determined using multiple regression analysis. RESULTS: Cross-sectional prevalence rates for VHs at baseline, 12, 24 and 36 months indicated VHs in approximately 50% of patients. A cumulative frequency of 82.7% of cases at the end of the study period exhibited VHs. The incidence rate for VHs was 457 cases per 1000 population. Longer disease duration, greater impairment in activities of daily living and higher rates of anxiety were most commonly associated with VHs. No factors predictive of VHs could be ascertained. CONCLUSIONS: When examined longitudinally, VHs affect more patients than is commonly assumed in cross-sectional prevalence studies. Clinicians should routinely screen for VHs throughout the disease course. Disease duration, impairment in activities of daily living and anxiety presented as co-morbidities associated with VHs in PD, and therefore those presenting with VHs should be screened for anxiety disorder and vice versa.

Differential bleaching susceptibility among coral taxa and colony sizes, relative to bleaching severity across Australia's Great Barrier Reef and Coral Sea Marine Parks.

Climate-induced coral bleaching represents the foremost threat to coral assemblages globally, however bleaching susceptibility varies among and within coral taxa. We compared bleaching susceptibility among 10 coral morpho-taxa and two colony size classes relative to reef-scale bleaching severity at 33 reefs across the Great Barrier Reef and Coral Sea Marine Parks in February-March 2020. Colony size and bleaching severity caused the hierarchy of bleaching susceptibility among taxa to change considerably. Notably, massive Porites shifted from being among the least likely taxa to exhibit bleaching, to among the most susceptible as overall bleaching severity increased. Juvenile corals (≤5 cm diameter) were generally more resistant to bleaching, except for Montipora and Pocillopora colonies, which were more likely to bleach than adults (>5 cm). These findings suggest that colony size and reef-scale bleaching severity are important determinants of bleaching susceptibility among taxa and provide insights into possible shifts in the structure of coral assemblages caused by bleaching events.

Coping in Parkinson's disease: an examination of the coping inventory for stressful situations.

BACKGROUND: Parkinson's disease (PD) brings with it a range of stresses and challenges with which a patient must cope. The type of coping strategies employed can impact upon well-being, although findings from coping studies in PD remain inconsistent. The variety of coping scales used without validation in PD has been cited as a possible cause of this inconsistency. The present study sought to examine the validity of the coping inventory for stressful situations (CISS) in a sample of patients with PD. METHODS: Five hundred and twenty-five patients with PD were recruited as part of a longitudinal investigation of mood states in PD. Four hundred and seventy-one participants completed the CISS. Confirmatory factor analysis was used to explore the structural validity of the scale. Internal reliability, test-retest reliability, convergent validity and discriminant validity were assessed using Cronbach's alpha, intraclass correlations and Pearson's correlations. RESULTS: Both three and four factor solutions were examined. The four factor model was found to provide a better fit of the data than the three factor model. The internal reliability, discriminant validity, convergent validity, and test-retest reliability of the CISS scales were shown to be good. Use of emotion-focused coping was associated with greater depression and anxiety whilst, task-oriented coping was associated with better psychological well-being. CONCLUSION: The results provide support for the validity and reliability of the CISS as a measure of coping in patients with PD. Further research into the relationship between coping and well-being is warranted. The identification of helpful and unhelpful coping strategies may guide the development of evidence-based therapies to improve well-being in patients with PD.

Trajectories of pain over 6 years in early Parkinson's disease: ICICLE-PD.

INTRODUCTION: Pain is a common non-motor symptom in Parkinson's disease (PD), affecting up to 85% of patients. The frequency and stability of pain over time has not been extensively studied. There is a paucity of high-quality studies investigating pain management in PD. To develop interventions, an understanding of how pain changes over the disease course is required. METHODS: One hundred and fifty-four participants with early PD and 99 age-and-sex-matched controls were recruited as part of a longitudinal study (Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation in PD, ICICLE-PD). Pain data were collected at 18-month intervals over 72 months in both groups using the Nonmotor Symptom Questionnaire (NMSQ), consisting of a binary yes/no response. Two questions from the Parkinson's Disease Questionnaire (PDQ-39) were analysed for the PD group only. RESULTS: Unexplained pain was common in the PD group and occurred more frequently than in age-matched controls. 'Aches and pains' occurred more frequently than 'cramps and muscle spasms' at each time point (p < 0.001) except 54 months. CONCLUSIONS: This study shows that pain is prevalent even in the early stages of PD, yet the frequency and type of pain fluctuates as symptoms progress. People with PD should be asked about their pain at clinical consultations and given support with describing pain given the different ways this can present.

Introduction of an assessment toolkit associated with increased rate of DLB diagnosis.

BACKGROUND: Dementia with Lewy bodies (DLB) and dementia in Parkinson's disease (PDD) are recognised to be under-recognised in clinical practice in the UK, with only one third to a half of expected cases diagnosed. We aimed to assess whether clinical diagnostic rates could be increased by the introduction of a structured assessment toolkit for clinicians. METHODS: We established baseline diagnostic rates for DLB and PDD in four memory clinics and three movement disorder/Parkinson's disease (PD) clinics in two separate geographical regions in the UK. An assessment toolkit specifically developed to assist with the recognition and diagnosis of DLB and PDD was then introduced to the same clinical teams and diagnostic rates for DLB and PDD were reassessed. For assessing DLB diagnosis, a total of 3820 case notes were reviewed before the introduction of the toolkit, and 2061 case notes reviewed after its introduction. For PDD diagnosis, a total of 1797 case notes were reviewed before the introduction of the toolkit and 3405 case notes after it. Mean values and proportions were analysed using Student's t test for independent samples and χ2 test, respectively. RESULTS: DLB was diagnosed in 4.6% of dementia cases prior to the introduction of the toolkit, and 6.2% of dementia cases afterwards, an absolute rise of 1.6%, equal to a 35% increase in the number of DLB cases diagnosed when using the toolkit (χ2 = 4.2, P = 0.041). The number of PD patients diagnosed with PDD was not found overall to be significantly different when using the toolkit: 9.6% of PD cases before and 8.2% of cases after its introduction (χ2 = 1.8, P = 0.18), though the ages of PD patients assessed after the toolkit's introduction were lower (73.9 years vs 80.0 years, t = 19.2, p < 0.001). CONCLUSION: Introduction of the assessment toolkit was associated with a significant increase in the rate of DLB diagnosis, suggesting that a structured means of assessing symptoms and clinical features associated with DLB can assist clinicians in recognising cases. The assessment toolkit did not alter the overall rate of PDD diagnosis, suggesting that alternate means may be required to improve the rate of diagnosis of dementia in Parkinson's disease.

Progression of Neuropsychiatric Symptoms over Time in an Incident Parkinson's Disease Cohort (ICICLE-PD).

BACKGROUND: Cross-sectional studies have identified that the prevalence of neuropsychiatric symptoms (NPS) in Parkinson's disease (PD) ranges from 70-89%. However, there are few longitudinal studies determining the impact of NPS on quality of life (QoL) in PD patients and their caregivers. We seek to determine the progression of NPS in early PD. METHODS: Newly diagnosed idiopathic PD cases (n = 212) and age-matched controls (n = 99) were recruited into a longitudinal study. NPS were assessed using the Neuropsychiatric Inventory with Caregiver Distress scale (NPI-D). Further neuropsychological and clinical assessments were completed by participants, with reassessment at 18 and 36 months. Linear mixed-effects modelling determined factors associated with NPI-D and QoL over 36 months. RESULTS: Depression, anxiety, apathy and hallucinations were more frequent in PD than controls at all time points (p < 0.05). Higher motor severity at baseline was associated with worsening NPI-D scores over time (ß = 0.1, p < 0.05), but not cognition. A higher NPI total score was associated with poorer QoL at any time point (ß = 0.3, p < 0.001), but not changed in QoL scores. CONCLUSION: NPS are significantly associated with poorer QoL, even in early PD. Screening for NPS from diagnosis may allow efficient delivery of better support and treatment to patients and their families.

Swallowing problems in Parkinson disease: frequency and clinical correlates.

BACKGROUND: Changes to the efficiency and integrity of swallowing mechanisms are inevitable in Parkinson disease (PD); however, it remains unclear how many people with PD are at risk of dysphagia. The aim of this study was to establish the frequency of impaired swallowing in people with PD and the relationship between swallowing performance and indicators of disease progression. METHODS: A community-based and hospital-based cohort of 137 individuals with PD were asked to drink 150 ml of water as quickly as possible while in an 'off drug' state. RESULTS: Thirty-one (23%) patients could not completely drink the full 150 ml. Swallowing rate (ml/sec) fell to more than 1 SD below published norms for 115 (84%) patients and to more than 2SD below for 44 (32%) individuals. There were moderate correlations between rate of swallowing and disease severity, depression and cognition, but not between swallowing speed and disease duration. There was poor correlation between subjective reports of dysphagia and performance on the water swallow test. CONCLUSIONS: Swallowing problems are frequent in PD. Self-report of 'no difficulty' is not a reliable indicator of swallowing ability. Studies employing more-objective assessment of aspiration risk to compare with water swallow test performance are advocated.

Tauopathies with parkinsonism: clinical spectrum, neuropathologic basis, biological markers, and treatment options.

Tauopathies with parkinsonism represent a spectrum of disease entities unified by the pathologic accumulation of hyperphosphorylated tau protein fragments within the central nervous system. These pathologic characteristics suggest shared pathogenetic pathways and possible molecular targets for disease-modifying therapeutic interventions. Natural history studies, for instance, in progressive supranuclear palsy, frontotemporal dementia with parkinsonism linked to chromosome 17, corticobasal degeneration, and Niemann-Pick disease type C as well as in amyotrophic lateral sclerosis/Parkinson-dementia complex permit clinical characterization of the disease phenotypes and are crucial to the development and validation of biological markers for differential diagnostics and disease monitoring, for example, by use of neuroimaging or proteomic approaches. The wide pathologic and clinical spectrum of the tauopathies with parkinsonism is reviewed in this article, and perspectives on future advances in the understanding of the pathogenesis are given, together with potential therapeutic strategies.

Impaired attention predicts falling in Parkinson's disease.

BACKGROUND: Cognitive deficits, in particular deficits of attention and executive function, may affect postural sway and balance in Parkinson's disease (PD). Our objective was to determine whether measures of attention were associated with falls in a large cohort of subjects with PD studied prospectively. METHODS: Patients meeting UK PD Society Brain Bank Criteria were included. Assessment included UPDRS III and the Cognitive Drug Research computerised assessment battery (CDR) from which Power of Attention, Continuity of Attention, cognitive reaction time and reaction time variability were derived. Falls were assessed prospectively using monthly fall diaries returned over a year following baseline assessment. RESULTS: One hundred and sixty four subjects completed fall diary datasets. One hundred and three (63%) fell one or more times during the 12 month period. Regression analysis revealed an association of fall frequency with poorer Power of Attention and increased reaction time variability, which was retained after correcting for UPDRS scores. CONCLUSIONS: Reduced power of attention and increased reaction time variability are associated with increased fall frequency in PD. This has implications for the identification of those most at risk of falling, and for the management and prevention of falls in this patient group.

Changes in the population and community structure of corals during recent disturbances (February 2016-October 2017) on Maldivian coral reefs.

Climate change is the greatest threat to coral reef ecosystems. In particular, increasing ocean temperatures are causing severe and widespread coral bleaching, contributing to extensive coral loss and degradation of coral reef habitats globally. Effects of coral bleaching are not however, equally apportioned among different corals, leading to shifts in population and community structure. This study explored variation in bleaching susceptibility and mortality associated with the 2016 severe mass bleaching in the Central Maldives Archipelago. Five dominant coral taxa (tabular Acropora, Acropora humilis, Acropora muricata, Pocillopora and massive Porites) were surveyed in February 2016 and October 2017 to test for changes in abundance and size structure. Substantial taxonomic differences in rates of mortality were observed; the most severely affected taxa, Acropora, were virtually extirpated during the course of this study, whereas some other taxa (most notably, massive Porites) were relatively unaffected. However, even the least affected corals exhibited marked changes in population structure. In February 2016 (prior to recent mass-bleaching), size-frequency distributions of all coral taxa were dominated by larger size classes with over-centralized, peaked distributions (negatively skewed with positive kurtosis) reflecting a mature population structure. In October 2017, after the bleaching, coral populations were dominated by smaller and medium size classes, reflecting high levels of mortality and injury among larger coral colonies. Pronounced changes in coral populations and communities in the Maldives, caused by coral bleaching and other disturbances (outbreaks of crown-of-thorns starfish and sedimentation), will constrain recovery capacity, further compounding upon recent coral loss.