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Patients with essential tremor exhibit heterogeneous cognitive functioning. Although the majority of patients fall under the broad classification of cognitively “normal,” essential tremor is associated with increased risk for mild cognitive impairment and dementia. It is possible that patterns of cognitive performance within the wide range of normal functioning have predictive utility for mild cognitive impairment or dementia. These cross-sectional analyses sought to determine whether cognitive patterns, or “clusters,” could be identified among individuals with essential tremor diagnosed as cognitively normal. We also determined whether such clusters, if identified, were associated with demographic or clinical characteristics of patients.
Elderly subjects with essential tremor (age >55 years) underwent comprehensive neuropsychological testing. Domain means (memory, executive function, attention, visuospatial abilities, and language) from 148 individuals diagnosed as cognitively normal were partitioned using k-means cluster analysis. Individuals in each cluster were compared according to cognitive functioning (domain means and test scores), demographic factors, and clinical variables.
There were three clusters. Cluster 1 (n = 64) was characterized by comparatively low memory scores (p < .001), Cluster 2 (n = 39) had relatively low attention and visuospatial scores (p < .001), and Cluster 3 (n = 45) exhibited consistently high performance across all domains. Cluster 1 had lower Montreal Cognitive Assessment scores and reported more prescription medication use and lower balance confidence.
Three patterns of cognitive functioning within the normal range were evident and tracked with certain clinical features. Future work will examine the extent to which such patterns predict conversion to mild cognitive impairment and/or dementia.
In this paper, we revisit our previous work in which we derive an effective macroscale description suitable to describe the growth of biological tissue within a porous tissue-engineering scaffold. The underlying tissue dynamics is described as a multiphase mixture, thereby naturally accommodating features such as interstitial growth and active cell motion. Via a linearization of the underlying multiphase model (whose nonlinearity poses a significant challenge for such analyses), we obtain, by means of multiple-scale homogenization, a simplified macroscale model that nevertheless retains explicit dependence on both the microscale scaffold structure and the tissue dynamics, via so-called unit-cell problems that provide permeability tensors to parameterize the macroscale description. In our previous work, the cell problems retain macroscale dependence, posing significant challenges for computational implementation of the eventual macroscopic model; here, we obtain a decoupled system whereby the quasi-steady cell problems may be solved separately from the macroscale description. Moreover, we indicate how the formulation is influenced by a set of alternative microscale boundary conditions.
Non-tuberculous mycobacterium encephalitis is rare. Since 2013, a global outbreak of Mycobacterium chimaera infection has been attributed to point-source contamination of heater cooler units used in cardiac surgery. Disseminated M. chimaera infection has presented many unique challenges, including non-specific clinical presentations with delays in diagnosis, and a high mortality rate among predominantly immunocompetent adults. Here, we describe three patients with fatal disseminated Mycobacterium chimaera infection showing initially non-specific, progressively worsening neurocognitive decline, including confusion, delirium, depression and apathy. Autopsy revealed widespread granulomatous encephalitis of the cerebrum, brain stem and spinal cord, along with granulomatous chorioretinitis. Cerebral involvement and differentiation between mycobacterial granulomas and microangiopathic changes can be assessed best on MRI with contrast enhancement. The prognosis of M. chimaera encephalitis appears to be very poor, but might be improved by increased awareness of this new syndrome and timely antimicrobial treatment.
This presentation will enable the learner to:
1.Describe the clinical, radiological and neuropathological findings of Mycobacterium chimaera encephalitis
2.Be aware of this rare form of encephalitis, and explain its diagnosis, prognosis and management
Declining mortality following invasive pneumococcal disease (IPD) has been observed concurrent with a reduced incidence due to effective pneumococcal conjugate vaccines. However, with IPD now increasing due to serotype replacement, we undertook a statistical analysis to estimate the trend in all-cause 30-day case fatality rate (CFR) in the North East of England (NEE) following IPD. Clinical, microbiological and demographic data were obtained for all laboratory-confirmed IPD cases (April 2006–March 2016) and the adjusted association between CFR and epidemiological year estimated using logistic regression. Of the 2510 episodes of IPD included in the analysis, 486 died within 30 days of IPD (CFR 19%). Increasing age, male sex, a diagnosis of septicaemia, being in ⩾1 clinical risk groups, alcohol abuse and individual serotypes were independently associated with increased CFR. A significant decline in CFR over time was observed following adjustment for these significant predictors (adjusted odds ratio 0.93, 95% confidence interval 0.89–0.98; P = 0.003). A small but significant decline in 30-day all-cause CFR following IPD has been observed in the NEE. Nonetheless, certain population groups remain at increased risk of dying following IPD. Despite the introduction of effective vaccines, further strategies to reduce the ongoing burden of mortality from IPD are needed.
The St. Louis aerosol was sampled during the period 16-22 August 1973 simultaneously at two locations using cascade impactors for sequential 12-hour samples. The six particle size fractions of each sampling were individually analyzed using PIXE for elements from S to Br and beyond and for heavy elements including Pb which permitted time variations of concentrations and particle size distributions to be followed and related to meteorological changes during the sampling period. In addition, the data were compared with average levels of the elements in coastal north Florida and maritime Bermuda as well as at a third St. Louis site. From this it appeared that some of the concentrations in St. Louis were at natural levels whereas others appeared to be higher and linked to air pollution sources. These relationships and others in this study may lead to criteria for distinguishing between pollutants and natural background in urban aerosols.
Emotion regulation dysfunction is characteristic of psychotic disorders, but little is known about how the use of specific types of emotion regulation strategies differs across phases of psychotic illness. This information is vital for understanding factors contributing to psychosis vulnerability states and developing targeted treatments. Three studies were conducted to examine emotion regulation across phases of psychosis, which included (a) adolescent community members with psychotic-like experiences (PLEs; n = 262) and adolescents without PLEs (n = 1,226); (b) adolescents who met clinical high-risk criteria for a prodromal syndrome (n = 29) and healthy controls (n = 29); and (c) outpatients diagnosed with schizophrenia or schizoaffective disorder (SZ; n = 61) and healthy controls (n = 67). In each study, participants completed the Emotion Regulation Questionnaire and measures of psychiatric symptoms and functional outcome. The three psychosis groups did not differ from each other in reported use of suppression; however, there was evidence for a vulnerability-related, dose-dependent decrease in reappraisal. Across each sample, a lower use of reappraisal was associated with poorer clinical outcomes. Findings indicate that emotion regulation abnormalities occur across a continuum of psychosis vulnerability and represent important targets for intervention.
The origin of record keeping is a key question in the development of social complexity and specialized economies, representing the first step towards the emergence of written communication. Yet the precursors of the world's earliest writing and its initial stages of development remain little understood. Small, geometric clay objects (‘tokens’) appear in the tenth millennium cal. bc, the start of the Neolithic in West Asia, prevailing into the first millennium. It is largely assumed that from their inception clay objects played a crucial role in record keeping, directly evolving into the world's earliest known writing. Utilizing new and previously unpublished Neolithic data comprising almost individually studied 3000 objects, accompanied by information from 56 further Neolithic sites, this article investigates the meaning of Neolithic ‘tokens’. Analysis proves the basis of their predominant interpretation to be incorrect; clay objects appear earlier than previously recognized and are not a necessary component of Neolithic agro-pastoral villages. ‘Tokens’ were multi-functional artefacts; even within a single site clay objects performed multiple roles. Though likely used in simple counting activities, this was not limited to the accounting of agricultural produce. Nor was counting the sole function of clay objects in the Neolithic. Clay objects were not created to administer agricultural produce and there is no evidence to suggest that in the Neolithic they formed part of a unified symbolic system.
This study examined the comminution of fresh herbage, subsequent nutrient release, and the characteristics of swallowed boli from three physically and chemically contrasting forages during ingestive mastication by dairy cows. The extent and pattern of nutrient release will determine their availability to rumen microflora, and potentially influence their efficiency of use. The forages evaluated were perennial ryegrass (ryegrass, Lolium perenne L., cv Alto AR37), lucerne (Medicago sativa L., cv Torlesse) and chicory (Cichorium intybus L., cv Choice). Experimental design was a 3×3 cross-over with three forages and three consecutive 1-day measurement periods, conducted twice. Six non-lactating, pregnant, multiparous Holstein-Friesian×Jersey cows (Bos taurus) were used, with the first cross-over applied to three mature (10.1±0.61 years old; BW 631±64 kg) cows, and the second to three young (4.8±0.02 years; BW 505±19 kg) cows. Fresh cut forage was offered to the cows following partial rumen evacuation. Swallowed boli were collected directly at the cardia at the commencement, middle and end of the first feeding bout of the first meal of the day. Forage species did not affect the fresh weight of ingested boli (mean 169 g, P=0.605) but the proportion of saliva in boli varied between forage. Boli of chicory contained the greatest amount of herbage material and least amount of saliva, whereas ryegrass boli were the opposite. Boli fresh weight tended to increase as time in the meal progressed, but the age of the cow was not shown to affect any boli characteristics or nutrient release. Particle size reduction was affected by forage, with 31%, 38% and 35% of chicory, lucerne and ryegrass herbage reduced to <2 mm. There was little evidence of relationship between comminution and any physical or chemical characteristic of the forage, except in ryegrass where extent of comminution was moderately correlated with herbage strength. Proportional release of herbage soluble carbohydrate exceeded that of N during mastication. Differences in loss of N were moderately correlated with the amount of N in the herbage (R2=0.53) but herbage comminution was not strongly correlated with release of either N or carbohydrate. These findings illustrate the complex animal×forage interactions that occur during mastication, and that it is not possible to infer nutrient loss from herbage based on herbage characteristics as the driver for this differ between species.
Objectives: Emerging work reveals the neuroanatomic changes that compromise metacognition; however, little is known about the impact of premorbid factors. Research suggests that psychological variables influence the perception of cognition, but whether they influence the accuracy of those perceptions (i.e., metacognition) has not been directly examined. Participants and Methods: Using Latent Class Analysis (LCA), we tested for discrete personality (NEOFFI) and mood (STAI, BDI-II, and GDS) classes among a community-based cohort of 151 older adults, enrolled in the NKI-Rockland study. Metamemory was calculated by comparing subjective memory ratings (modified Cognitive Failures Questionnaire) to objective memory (Rey Auditory Verbal Learning Test) to determine the degree to which individuals were overconfident, underconfident, or accurate in their self-assessment. A generalized linear model was used to examine whether metamemory differed across the emergent classes. A one sample t test was used to determine whether the metamemory scores of the emergent classes were statistically significantly different from zero, that is, over or under confident. Results: Two discrete classes emerged in the LCA: Class 1 was characterized predominantly by high extraversion and conscientiousness and low neuroticism and anxiety; Class 2 was characterized predominantly by low extraversion and conscientiousness and high neuroticism and anxiety. Metamemory differed significantly as a function of Class Membership (F(4,151)=5.42; p<.001), with Class 1 demonstrating accurate metamemory (M=0.21; SD=1.31) and Class 2 demonstrating under-confidence (M=−0.59; SD=1.39) in their memory. Conclusions: The significant association between psychological factors and metamemory knowledge accuracy suggests that such characteristics may be important to consider in the conceptualization, assessment, and treatment of metacognitive disturbances. (JINS, 2018, 24, 498–510)
In order to extend diagnoses of recent sea-ice variations beyond the past few decades, a century-scale digital dataset of Arctic sea-ice coverage has been compiled. For recent decades, the compilation utilizes satellite-derived hemispheric datasets. Regional datasets based primarily on ship reports and aerial reconnaissance are the primary inputs for the earlier part of the 20th century. While the various datasets contain some discrepancies, they capture the same general variations during their period of overlap. The outstanding feature of the time series of total hemispheric ice extent is a decrease that has accelerated during the past several decades. The decrease is greatest in summer and weakest in winter, contrary to the seasonality of the greenhouse changes projected by most global climate models. The primary spatial modes of sea-ice variability diagnosed in terms of empirical orthogonal functions, also show a strong seasonality. The first winter mode is dominated by an opposition of anomalies in the western and eastern North Atlantic, corresponding to the well-documented North Atlantic Oscillation. The primary summer mode depicts an anomaly of the same sign over nearly the entire Arctic and captures the recent trend of sea-ice coverage.
Sea-ice thickness distributions from 12 submarine cruises under the North Pole are used to evaluate and enhance the results of sea-ice model simulations. The sea-ice models include versions with cavitating fluid and elastic-viscous-plastic rheologies, and versions with a single thickness and with multiple (5–27) thicknesses in each gridcell. A greater portion of the interannual variance of observed mean thickness at the Pole is captured by the multiple-thickness models than by the single-thickness models, although even the highest correlations are only about 0.6. After The observed thickness distributions are used to ˚tune" the model to capture the primary mode of the distribution, the largest model-data discrepancies are in the thin-ice tail of the distribution. In a 41 year simulation ending in 1998, the model results show a pronounced decrease of mean ice thickness at the Pole around 1990; the minimum simulated thickness occurs in summer 1998. The decrease coincides with a shift of the Arctic Oscillation to its positive phase. The smallest submarine-derived mean thickness occurs in 1990, but no submarine data were available after 1992. The submarine-derived thicknesses for 1991 and 1992 are only slightly smaller than the 12–case mean.
The importance of serial sections for the analysis of the morphology of fossil organisms has been stressed by a number of authors (e.g., Westbroek, 1967, 1969; Cooper, 1983; Sandy, 1986, this volume, Chapter 14) because they provide a way to visualize the three-dimensional structure, both internal and external, of specimens that cannot be studied in other ways. The importance of internal structures for the taxonomy of many groups (e.g., the brachidia of brachiopods; Westbroek et al., 1976; Cooper, 1983) makes the study of serial sections imperative in many cases for proper taxonomic identification.
Plants and shelly marine invertebrates often have diverse and densely packed communities that generate dense accumulations of organic remains. In contrast, populations in vertebrate communities are relatively dispersed in life, and normal annual mortality results in a relatively low density of remains scattered over the land surface. This attritional “bone rain” differs from unusual circumstances such as mass mortality and predator bone-collecting, which can generate high density accumulations of vertebrate remains in a short period of time.