Turbulence Measurements in Dilute Polymer Flows

A hot-film sensor was flush-mounted in the wall of a four-inch pipe and was calibrated as a function of wall shear stress. Flows with water and with homogeneous aqueous solutions of Polyox WSR-301 were utilized. The heat transfer characteristics of the sensor were reduced for polymer flows. Measurements of the number of zeroes and the frequency spectra for the turbulent fluctuations were obtained for a variety of test conditions. The effects of Polyox WSR-301 on surface pressure fluctuations on both smooth and rough surfaces were also measured

Fish swimming in schools save energy regardless of their spatial position

For animals, being a member of a group provides various advantages, such as reduced vulnerability to predators, increased foraging opportunities and reduced energetic costs of locomotion. In moving groups such as fish schools, there are benefits of group membership for trailing individuals, who can reduce the cost of movement by exploiting the flow patterns generated by the individuals swimming ahead of them. However, whether positions relative to the closest neighbours (e.g. ahead, sided by side or behind) modulate the individual energetic cost of swimming is still unknown. Here, we addressed these questions in grey mullet Liza aurata by measuring tail-beat frequency and amplitude of 15 focal fish, swimming in separate schools, while swimming in isolation and in various positions relative to their closest neighbours, at three speeds. Our results demonstrate that, in a fish school, individuals in any position have reduced costs of swimming, compared to when they swim at the same speed but alone. Although fish swimming behind their neighbours save the most energy, even fish swimming ahead of their nearest neighbour were able to gain a net energetic benefit over swimming in isolation, including those swimming at the front of a school. Interestingly, this energetic saving was greatest at the lowest swimming speed measured in our study. Because any member of a school gains an energetic benefit compared to swimming alone, we suggest that the benefits of membership in moving groups may be more strongly linked to reducing the costs of locomotion than previously appreciated

The feasibility and acceptability of a psychosocial intervention to support people with dementia with Lewy bodies and family care partners

OBJECTIVES: Psychosocial support for people with dementia with Lewy bodies (DLB) and family care partners is frequently lacking, despite the need expressed by those with lived experience. Our objective was to examine the feasibility and acceptability of an intervention designed to build coping capability. DESIGN: The design was non-randomised with all participants receiving the intervention. SETTING: The setting was a Memory Assessment and Management Service in the Northeast of England. PARTICIPANTS: Participants comprised 19 dyads consisting of a person with DLB and a family care partner. INTERVENTION: The intervention was group-based, with weekly sessions attended for up to four successive weeks. It was informed by Social Cognitive Theory. MEASUREMENTS: Data were collected on recruitment, attendance and attrition, self-efficacy, mood, stress and participant experience. RESULTS: Recruitment was achieved with minimal attrition and three successive groups were delivered. Care partners felt more in control and able to cope in at least 3 of 13 areas with 73% feeling this way in eight or more areas. Three themes were identified from post-intervention interviews: people like us, outcomes from being a group member and intervention design. CONCLUSIONS: A DLB-specific group intervention is acceptable to people with DLB and family care partners, and recruitment is feasible within a specialist service. Participation may enhance understanding of this condition and reduce social isolation. It may improve care partners' coping capability particularly if targeted towards those with low prior understanding of DLB and more stress. Means of evaluating outcomes for people with DLB need further development

Contributors to the January Issue/Notes

Notes by John J. Killen, James H. Neu, John W. Hackett, Jr., James E. Diver, James C. Daner, Richard F. Swisher, and Leo L. Linck

Contributors to the January Issue/Notes

Notes by John J. Killen, James H. Neu, John W. Hackett, Jr., James E. Diver, James C. Daner, Richard F. Swisher, and Leo L. Linck

The challenges of COVID-19 for people with dementia with Lewy bodies and family caregivers.

Introduction During the current SARS-CoV-2 pandemic dementia has been identified as disproportionally common in adults aged over 65 who develop severe COVID-19.1 Observational data from the International Severe Acute Respiratory and Emerging Infections Consortium also confirms a high prevalence of dementia in older adults hospitalised with COVID-19.2 It is so far unclear whether there is any direct effect of dementia pathologies as dementia is a disease of old age, and thus likely to be associated with a variety of comorbidities, in particular, frailty, which may further exacerbate the risk of severe infection. In addition up to one third of COVID patients have demonstrated neurological sequelae3 and there may be both direct (viral infection within the brain, vascular effects) and indirect effects (e.g. host immunological response, impact of treatment) of SARS-CoV-2 on the brain.4 It is therefore possible that SARS-CoV-2 infection may accentuate any pre-existing neurodegenerative disease

Electroencephalographic derived network differences in Lewy body dementia compared to Alzheimer's disease patients.

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) require differential management despite presenting with symptomatic overlap. Currently, there is a need of inexpensive DLB biomarkers which can be fulfilled by electroencephalography (EEG). In this regard, an established electrophysiological difference in DLB is a decrease of dominant frequency (DF)-the frequency with the highest signal power between 4 and 15 Hz. Here, we investigated network connectivity in EEG signals acquired from DLB patients, and whether these networks were able to differentiate DLB from healthy controls (HCs) and associated dementias. We analysed EEG recordings from old adults: HCs, AD, DLB and Parkinson's disease dementia (PDD) patients. Brain networks were assessed with the minimum spanning tree (MST) within six EEG bands: delta, theta, high-theta, alpha, beta and DF. Patients showed lower alpha band connectivity and lower DF than HCs. DLB and PDD showed a randomised MST compared with HCs and AD in high-theta and alpha but not in DF. The MST randomisation in DLB and PDD reflects decreased brain efficiency as well as impaired neural synchronisation. However, the lack of network topology differences at the DF between all dementia groups and HCs may indicate a compensatory response of the brain to the neuropathology.The research was funded by The Newcastle upon Tyne Hospitals NHS Charity, and supported by the Northumberland Tyne & Wear National Health Service (NHS) Foundation Trust and the National Institute of Health Research (NIHR) Biomedical Research Centre (BRC) at Newcastle University. S.G. was supported by the NIHR MedTech In vitro diagnostic Co-operatives scheme (ref MIC-2016-014). The study —participant recruitment and data collection— was funded by an intermediate clinical Wellcome Trust Fellowship (WT088441MA) to J-P.T

The assessment of cognition in visually impaired older adults

Background: visual and cognitive impairments are common in later life. Yet there are very few cognitive screening tests for the visually impaired. Objective: to screen for cognitive impairment in the visually impaired. Methods: case-control study including 150 elderly participants with visual impairment (n=74) and a control group without visual impairment (n=76) using vision-independent cognitive tests and cognitive screening tests (MMSE and clock drawing tests (CDT)) which are in part vision dependent. Results: the scoring of the two groups did not differ in the vision-independent cognitive tests. Visually impaired patients performed poorer than controls in the vision-dependent items of the MMSE (T=7.3; df: 148; P<0.001) and in CDT (T=3.1; df: 145; P=0.003). No group difference was found when vision-independent items were added to MMSE and CDT. The test score gain by the use of vision-independent items correlated with the severity of visual impairment (P<0.002). Conclusion: visually impaired patients benefit from cognitive tests, which do not rely on vision. The more visually impaired the greater the benefi

Groundwater trend analysis and salinity risk assessment for the south-west agricultural region of Western Australia, 2007–12

Dryland salinity is a hydrologically driven land degradation hazard in the south-west agricultural region of Western Australia (WA). Shallow-rooted annual crops and pastures transpire significantly less water than the native vegetation they replaced, leading to an increase in recharge, rising groundwater levels and the development of shallow watertables in areas where often none existed previously. Rising groundwater levels mobilise soluble salts, naturally stored at high concentrations in the regolith. These salts can be concentrated in the root zone of vegetation by evapotranspiration