Working Memory and Falls Risk in Older Adults: An Event-Related Potential Study

BACKGROUND: The aging population is rapidly increasing, where currently in North America, the population of older adults (ages 60+) outnumbers the population of children. Falls are a major concern for older adults and their quality of life. Cognitive impairment has been shown to be declined in older adults at-risk for falls, but working memory has not been thoroughly investigated within this population. PURPOSE: To examine differences in Non-Fallers, Moderate Risk for Falls, and Fallers in a working memory task using electroencephalography (EEG). METHODS: Older adults (n=44, female=27) aged 60 – 80 years (m=68.8, SD=4.7) completed two sessions. The first session incorporated general demographic questionnaires and Tinetti’s Mobility Test. Participants were classified as Non-Fallers, Moderate Risk for Falls, or Fallers based on their Tinetti’s Mobility Test results and their falls history. The second session had participants complete the n-back, a working memory test, while behavioural and EEG results were recorded. RESULTS: We found that in the 2-Back test, behaviorally those who were at risk performed the worst (slower reaction time and decreased accuracy) in comparison to the Non-Fallers and Fallers. However, from the EEG results, Fallers were more cognitively impaired, with earlier latencies for the N2 and P3 components in comparison to the other groups, while the Moderate Risk for Falls group were significantly impaired in peak latencies in the N2 only in comparison to the Non-Faller group. CONCLUSIONS: Individuals at risk and fallers differ in their impairment in working memory in comparison to non-fallers. Working memory and falls risk should be further investigated as a proactive approach to the falls phenomena

Electrical Control of Linear Dichroism in Black Phosphorus from the Visible to Mid-Infrared

The incorporation of electrically tunable materials into photonic structures such as waveguides and metasurfaces enables dynamic control of light propagation by an applied potential. While many materials have been shown to exhibit electrically tunable permittivity and dispersion, including transparent conducting oxides (TCOs) and III-V semiconductors and quantum wells, these materials are all optically isotropic in the propagation plane. In this work, we report the first known example of electrically tunable linear dichroism, observed here in few-layer black phosphorus (BP), which is a promising candidate for multi-functional, broadband, tunable photonic elements. We measure active modulation of the linear dichroism from the mid-infrared to visible frequency range, which is driven by anisotropic quantum-confined Stark and Burstein-Moss effects, and field-induced forbidden-to-allowed optical transitions. Moreover, we observe high BP absorption modulation strengths, approaching unity for certain thicknesses and photon energies

Distinct neuroanatomical and neuropsychological features of Down syndrome compared to related neurodevelopmental disorders: a systematic review

ObjectivesWe critically review research findings on the unique changes in brain structure and cognitive function characteristic of Down syndrome (DS) and summarize the similarities and differences with other neurodevelopmental disorders such as Williams syndrome, 22q11.2 deletion syndrome, and fragile X syndrome.MethodsWe conducted a meta-analysis and systematic literature review of 84 studies identified by searching PubMed, Google Scholar, and Web of Science from 1977 to October 2022. This review focuses on the following issues: (1) specific neuroanatomic and histopathological features of DS as revealed by autopsy and modern neuroimaging modalities, (2) language and memory deficits in DS, (3) the relationships between these neuroanatomical and neuropsychological features, and (4) neuroanatomic and neuropsychological differences between DS and related neurodevelopmental syndromes.ResultsNumerous post-mortem and morphometric neuroimaging investigations of individuals with DS have reported complex changes in regional brain volumes, most notably in the hippocampal formation, temporal lobe, frontal lobe, parietal lobe, and cerebellum. Moreover, neuropsychological assessments have revealed deficits in language development, emotional regulation, and memory that reflect these structural changes and are more severe than expected from general cognitive dysfunction. Individuals with DS also show relative preservation of multiple cognitive, linguistic, and social domains compared to normally developed controls and individuals with other neurodevelopmental disorders. However, all these neurodevelopment disorders exhibit substantial heterogeneity among individuals.ConclusionPeople with Down syndrome demonstrate unique neurodevelopmental abnormalities but cannot be regarded as a homogenous group. A comprehensive evaluation of individual intellectual skills is essential for all individuals with neurodevelopment disorders to develop personalized care programs

A 7-year review of clinical characteristics, predisposing factors and outcomes of post-keratoplasty infectious keratitis: the Nottingham infectious keratitis study

Background/objectives: Post-keratoplasty infectious keratitis (PKIK) is a unique sight-threatening clinical entity which often poses significant therapeutic challenges. This study aimed to examine the clinical presentation, risk factors, management, and clinical outcomes of PKIK. Methods: This was a retrospective study of all patients who presented to the Queen’s Medical Centre, Nottingham, with PKIK between September 2015 and August 2022 (a 7-year period). Relevant data on types of keratoplasty, clinical presentations, causative microorganisms, management, and outcome were analyzed. Results: Forty-nine PKIK cases, including four cases of interface infectious keratitis, were identified during the study period. The most common graft indications for PKP, DALK and EK were failed grafts (9, 37.5%), keratoconus (6, 54.5%) and Fuchs endothelial corneal dystrophy (FECD; 8, 57.1%), respectively. Staphylococcus spp. were the most commonly identified organisms (15, 50.0%). Bullous keratopathy (18, 36.7%), ocular surface disease (18, 36.7%), and broken/loose sutures (15, 30.6%) were the most common risk factors. Concurrent use of topical steroids was identified in 25 (51.0%) cases. Of 31 functioning grafts at presentation, 12 (38.7%) grafts failed at final follow-up with 15 (48.4%) patients retaining a CDVA of ≥1.0 logMAR. The overall estimated 5-year survival rate post-PKIK was 55.9% (95% CI, 35.9%-75.9%), with DALK having the highest survival rate [63.6% (95% CI, 28.9%-98.3%)], followed by EK [57.1% (95% CI, 20.4%-93.8%)] and PKP [52.7% (95% CI, 25.1%-80.3%)], though no statistical difference was observed (p=0.48). Conclusions: PKIK represents an important cause of IK and graft failure. Bullous keratopathy, OSD and suture-related complications are the commonest risk factors, highlighting the potential benefit of prophylactic topical antibiotics (for unhealthy ocular surface) and early suture removal (where possible) in reducing the risk of PKIK. Graft survival may be higher in lamellar keratoplasty following PKIK but larger studies are required to elucidate this observation

Multi-center evaluation of analytical performance of the Beckman Coulter AU5822 chemistry analyzer

Objectives Our three academic institutions, Indiana University, Northwestern Memorial Hospital, and Wake Forest, were among the first in the United States to implement the Beckman Coulter AU5822 series chemistry analyzers. We undertook this post-hoc multi-center study by merging our data to determine performance characteristics and the impact of methodology changes on analyte measurement. Design and methods We independently completed performance validation studies including precision, linearity/analytical measurement range, method comparison, and reference range verification. Complete data sets were available from at least one institution for 66 analytes with the following groups: 51 from all three institutions, and 15 from 1 or 2 institutions for a total sample size of 12,064. Results Precision was similar among institutions. Coefficients of variation (CV) were 10% included direct bilirubin and digoxin. All analytes exhibited linearity over the analytical measurement range. Method comparison data showed slopes between 0.900-1.100 for 87.9% of the analytes. Slopes for amylase, tobramycin and urine amylase were 1.5, due to known methodology or standardization differences. Consequently, reference ranges of amylase, urine amylase and lipase required only minor or no modification. Conclusion The four AU5822 analyzers independently evaluated at three sites showed consistent precision, linearity, and correlation results. Since installations, the test results had been well received by clinicians from all three institutions

Associations between atrial cardiopathy and cerebral amyloid: The ARIC-PET study

Background Atrial fibrillation (AF) is a risk factor for cognitive decline, possibly from silent brain infarction. Left atrial changes in structure or function (atrial cardiopathy) can lead to AF but may impact cognition independently. It is unknown if AF or atrial cardiopathy also acts on Alzheimer disease-specific mechanisms, such as deposition of β-amyloid. Methods and Results A total of 316 dementia-free participants from the ARIC (Atherosclerosis Risk in Communities) study underwent florbetapir positron emission tomography, electrocardiography, and 2-dimensional echocardiography. Atrial cardiopathy was defined as ≥1: (1) left atrial volume index \u3e34 mL/

Influenza- and respiratory syncytial virus-associated adult mortality in Soweto

Background: Influenza and respiratory syncytial virus (RSV) infections cause seasonal excess mortality and hospitalisation in adults, particularly the elderly, in high-income countries. Little information exists on the impact of these infections on African adults. Objectives: To estimate influenza- and RSV -related adult mortality, stratified by age, and hospitalisation in Soweto, South Africa. Study design: A retrospective hospital-based study in Soweto from 1997-1999 to estimate influenza- and RSV -related excess all-cause deaths and hospitalisation using a rate-difference method. It was based on influenza seasons of varying severity provided by surveillance data. Results: Influenza seasons were significantly associated with excess mortality in adults across all 3 years, except for 18-64 year olds in 1998. Excess mortality was highest in those ≥65 years of age, 82.8 /100 000 population in the mild 1997 season and 220.9 / 100 000 in the severe 1998 season. Influenza significantly increased adult medical hospitalisation in the severe 1998 season alone. RSV did not significantly affect mortality or hospitalisation. Conclusions: Influenza-related mortality was substantial and disproportionately affected the elderly. Influenza vaccination for the elderly needs consideration. The RSV -related burden was not significantly increased but merits observation over a longer period.