Post-stroke neuropsychological screening and assessment: psychometrics, validation, and predictive value for functional outcomes

Neuropsychological screening and assessment of cognitive changes following stroke requires the use of standardised and well validated tools to ensure the most accurate and evidence-based assessment of a patient’s abilities.The importance of cognitive assessment comes from the high relation between cognitive impairment and later recovery [1–3]. In my DPhil, I aimed to examine different cognitive screening tools and provide validity evidence for their use in assessing post-stroke cognitive impairment. The first chapter examined the shift in modality of cognitive assessment during the COVID-19 pandemic in a completed web-based questionnaire of 114 allied health professionals (majority UK). This study was conducted at the height of the pandemic and provided time sensitive information about how the use of cognitive testing had changed. I found that the frequency of cognitive testing did not necessarily decrease, but that the modality changed to more remote and video based assessments. The rates of change were lower than other studies at the time, that primarily sampled neuropsychologists from the United States. Within the same chapter, I detailed a study, that provided some evidence for the valid use of a remote version of the Oxford Cognitive Screen (OCS). This study used 40 stroke survivors who had been administered the OCS both in person and remotely, in counterbalanced order. I found that there were minimal meaningful differences in performance across versions, and limited occurrences of a participant being considered impaired on one version and not on the other. This meant that, in light of the pandemic, I had provided some validity evidence for a tool usable via remote administration. The second chapter provided some clinical validation evidence of a computer tablet-based extension of the OCS, named the OCS-Plus. OCS-plus is a recently standardized and normed domain-general cognitive screening tool. Prior to this DPhil, there was only psychometric validation in 320 healthy ageing adults and no evidence for use in stroke. Here I examined OCS-Plus data from 347 stroke survivors (n=181 =6 months post-stroke) and compared performance of a subset of them to a neuropsychological battery and/or the Montreal Cognitive Assessment (MoCA). I found that the OCS-Plus met convergent and divergent validation criteria compared to the neuropsychological battery, and detected cognitive impairments in a large proportion of those classed as unimpaired on MoCA (100%) and OCS(98.50%). This project showed that the OCS-Plus is valid as a screening tool in stroke from subacute to chronic usage. The third chapter detailed work regarding the Oxford Digital Multiple Errands Test (OxMET), which had previously been standardised and normed in 124 healthy controls and compared to 105 chronic (>6 months post-stroke) stroke survivors. In part one of chapter 3, I examined the OxMET in relation to the in-person Multiple Errands Test - Home version (MET-Home) in 98 participants, to determine evidence for convergence between the MET, as well as feasibility and acceptability for each MET. I recruited 48 stroke survivors and 50 healthy ageing adults to take part. I found that both METs met convergence criteria (r>=.30). I found the OxMET to be more feasible and acceptable by participants, but that there was an appropriate time and sample to use for each MET and thus both are satisfactory tools. In part 2 of chapter 3, I examined the predictive validity of the OxMET taken subacutely with stroke survivors to clinically relevant future functional outcomes. The findings were clear that the OxMET was associated with both basic (n=117) and instrumental (n=66) activities of daily living, although more so with instrumental, over and above the contribution of other demographic and cognitive factors. The aim of the work presented in this thesis was to provide clinicians with an evidence base to make judgement about which tools are best practice for use, and to highlight both strengths and weaknesses of each tool presented. None of the tests presented in this thesis are able to fully capture the full depth of human cognition nor the rich idiosyncrasies of real everyday behavior. Health care professionals should always follow latest guidance and be educated in best evidence-based screening use and trained in tools they administer

An Occurrence of Bentonite in Houston County, Texas

Bentonite was discovered in Houston County in 1940 by a staff member of the Bureau of Economic Geology. On correlation of the sections in which the bentonite was exposed, namely, at Hurricane Bayou and Alabama Ferry, it was found that, though these localities were some 20 miles apart, the two sections were almost identical. This led to the obvious conclusion that the shale member containing the bentonite was continuous throughout the intervening area. Therefore, it was the work of this project to trace this shale member with its accompanying bentonite beds by means of outcrops, auger holes, and excavations. Surveys were made of the sites that encountered or exposed the bentonite, and the results were plotted on base maps made from aerial photographs.Bureau of Economic Geolog

Predictive validity of the Oxford digital multiple errands test (OxMET) for functional outcomes after stroke

The Oxford Digital Multiple Errands Test (OxMET) is a brief computer-tablet based cognitive screen, intended as an ecologically valid assessment of executive dysfunction. We examined aspects of predictive validity in relation to functional outcomes. Participants (≤ 2 months post-stroke) were recruited from an English-speaking stroke rehabilitation in-patient setting. Participants completed OxMET. The Barthel Index, Therapy Outcome Measure (TOMS), and modified Rankin Scale (mRS) were collected from medical notes. Participants were followed up after 6-months and completed the Nottingham Extended Activities of Daily Living (NEADL) scale. 117 participants were recruited (M = 26.18 days post-stroke (SD = 25.16), mean 74.44yrs (SD  = 12.88), median NIHSS 8.32 (IQR = 5-11)). Sixty-six completed a follow-up (M = 73.94yrs (SD  = 12.68), median NIHSS 8 (IQR = 4-11)). Significant associations were found between TOMS and mRS. At 6-month follow up, we found a moderate predictive relationship between the OxMET accuracy and NEADL (R2 = .29, p

Capturing cropland and grassland management impacts on soil carbon in the UK LULUCF inventory

This project aimed to identify the extent to which emissions due to changes in Soil Organic Carbon (SOC) stocks arising from Cropland and Grassland/Grazing Land management can be incorporated into the UK’s Land Use, Land Use Change and Forestry (LULUCF) inventory. Key management activities were identified which might affect SOC stocks. A literature review carried out as part of the project concluded that tillage reduction cannot be considered a reliable management option to increase the SOC content of UK soils. However increasing crop residue returns and increasing inputs of manure and fertiliser could increase SOC stock although the SOC stock increases resulting from manure and fertiliser inputs could be outweighed by increases nitrous oxide emissions and the risk of nitrate run-off. The review found that increasing crop yields through increased fertilisation and improved crop rotation could increase the annual input of crop residues and root exudate to soils and hence increase SOC on low fertility soils. Manure additions resulted in greater C sequestration than the addition of equivalent amounts of N as mineral fertiliser and the effect lasted longer. However, increasing inputs of nitrogen from fertiliser or manure risk increasing N2O emissions which could negate any increases in SOC stock. IPCC default stock change factors were judged to be inappropriate to the UK, based on expert opinion and the literature review findings. Therefore the project used the Daily DayCent and Landscape DNDC models to attempt to estimate stock change factors for Cropland management activities under UK conditions. Although based on a very limited dataset this suggested that the effect of Cropland management activities under UK conditions might be less than implied by the IPCC stock change factors. Tillage reduction was found to have little effect on SOC stocks. Increasing manure and crop residue inputs increased SOC stocks, with manure inputs being particularly effective. A framework for reporting SOC stock changes resulting from Cropland management was developed, and used to assess mitigation options. Overall the impact of Cropland Management on SOC is likely to be very small compared to other activities in the LULUCF inventory such as land use change. The most effective mitigation option was using Cropland from annual tillage crops to perennial crops, fallow and set aside. However given the need for food production there is limited scope for such change. Increasing manure, fertiliser and crop residue inputs gave smaller increases in SOC stocks, but practical considerations limit the scope of these actions. Lack of field data on the effect of Grassland improvement on SOC stocks was identified as a knowledge gap. The literature review suggested that intensification could increase SOC stocks under pasture on mineral soils. However, expert opinion suggested that this might not be the case for rough grazing on organo-mineral soils, where intensification might lead to SOC loss. This lack of data meant that it was not possible to calibrate or validate models to estimate UK specific stock change factors for Grassland. As the IPCC stock change factors were judged to be inappropriate to UK conditions assessment of the mitigation potential of Grassland management using these factors was not carried out to avoid presenting potentially misleading results. Suggested strategies for filling these knowledge gaps are outlined in the report. Attempts to assess grass/crop rotation patterns across the UK using data from the Integrated Administration and Control System (IACS) used to handle Common Agricultural Policy (CAP) payments were hampered by difficulties in obtaining access to the data. However land use change matrices were generated for England and Wales, and used to map areas of change. Subject to data availability, this approach could be used in future inventories to give a better representation the effect of rotation patterns on SOC stocks

MexLog Saddle

MexLog, a company specializing in the initial delivery of semi-trucks from production to sales, requires a simpler, smaller, and lighter weight system for the transportation of modern semi trucks. MexLog currently uses two saddles: The FES saddle (Rhino) and combo saddle. The combo cannot be used in the US for highway trucks due to height.The Rhino weighs 2200 lbs and is roughly 24 ft long. Therefore, MexLog cannot ship back more than 18 saddles due to a 39,500 lb limit, which means MexLog has to spend more money to return saddles than anything else. The new proposed design is constructed with I-beams and the same material the Rhino is made from(carbon steel) but shortened by about 10 ft from the back beam of the Rhino to make it roughly 14.2 ft long. In addition, the design of the connection point has been changed to include the head of a combo saddle to the end of the beam. Furthermore, to reduce the high moment that the kingpin might experience, a support beam has been added to the rear end of the semi truck frame. The estimated total weight of the proposed design is 650 lbs, which allows MexLog to ship 60 saddles

Introducing the Tele-OCS: Preliminary evidence of validity for a remotely administered version of The Oxford Cognitive Screen

BackgroundRemote cognitive assessments are increasingly used with the rising popularity of teleneuropsychology. Here, we evaluated the performance of the remotely administered Oxford Cognitive Screen (Tele-OCS) compared to in-person administration in adult stroke survivors.Methods40 stroke survivors ( M age = 69.30, SD = 10.44; sex = 30% female) completed in-person and remote versions of the OCS on average 30 days apart, with different trained examiners. The order of administration was counterbalanced. Cohen's d estimates were used to compare performance between modalities.ResultsWe found that the proportion of OCS subtasks impaired did not differ across modalities ( d <.001). With regards to raw subtask scores, only the picture naming subtask and executive score from the trail making subtask were found to be statistically different across modalities, though raw differences were minimal (<1 point difference on average). These statistical differences did not affect impairment classifications.ConclusionsThe Tele-OCS classified cognitive impairments in a comparable way to the in-person version. The validation of the Tele-OCS allows for remote assessment to increase accessibility and pragmatically aid in addressing the clinical need for stroke-specific cognitive screening in a wider population

Nutritional limitations to the early growth of rainforest timber trees in north Queensland

Most of the soils in the humid tropics of north Queensland available for growing rainforest trees are low in available nutrients. The major nutritional deficiencies have been classified according to soil parent material in order to develop a deficiency ‘risk’ table. From glasshouse trials using soils from across the region, most macronutrients (nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), and sulphur (S)), apart from magnesium (Mg), has been found to be deficient in at least one soil, and every soil studied was deficient in at least one nutrient. Rainforest tree species responded to nutritional deficiencies in different ways and there may be an unrecognised loss in growth potential. Tree growth can be depressed under limiting nutrient supply but remain undiagnosed, as visual deficiency symptoms may not develop. We present a number of techniques to manage nutrients in timely and cost effective ways. These include techniques to ensure a continuous supply of nutrients to the roots during transplanting, rapid tests for deficiencies of N and P, and recognition of visual diagnostic symptoms of deficiency

Validating the OCS‐Plus against a clinical standard: A brief report

This research aimed to determine the sensitivity and clinical validity of the OCS‐Plus, a stroke‐specific tablet‐based cognitive screening tool, in comparison with the MoCA, a routinely used screening tool, after stroke. Eighty‐six patients were recruited from Oxfordshire stroke wards over a 22‐month period and completed both screens. Overall, we found that the OCS‐Plus has good convergent validity and excellent sensitivity when compared with the MoCA. The OCS‐Plus is therefore of potential benefit to those seeking a sensitive screening tool