40 research outputs found
Evaluation of Mental Health First Aid from the Perspective Of Workplace End UseRsâEMPOWER: protocol of cluster randomised trial phase
Background: Mental Health First Aid (MHFA) is a mental health intervention that teaches people how to identify, understand and help someone who may be experiencing a mental health issue. Reviews of the implementation of MHFA found between 68 and 88% of trained Mental Health First Aiders had used their skills when in contact with someone experiencing mental health difficulties. Reviews evaluating the impact of MHFA suggest positive outcomes. However, to date, there has been no systematic, rigorous evaluation of the impact of MHFA on recipients of the intervention, the organisations providing it and the cost-effectiveness of MHFA overall. This trial will evaluate the effectiveness and cost-effectiveness of MHFA.
Methods: The study is a multi-centred, two-arm clustered randomised controlled trial. Organisations will be randomly allocated to the control or intervention (estimated sample size 800 recipients). The intervention is the standard MHFA intervention provided by Mental Health First Aid England (MHFAE). The control condition will be organisations having a brief consultation from MHFAE on promoting mental health and well-being in the workplace. The primary outcome is health seeking behaviour, measured using the Actual Help Seeking Questionnaire, at 6 monthsâ follow-up. Data collection will be undertaken at baseline (T0), post-interventionâup to 3 months (T1), at 6 months (T2), 12 months (T3) and 24 months (T4). The primary analysis will be conducted on those participants who receive MHFA, a per protocol analysis.
Discussion: The study is the first to evaluate the effect of MHFA in the workplace on employees with direct and indirect experience of the intervention, when compared with usual practice. Being also the first to assess, systematically, the social impact of MHFA and investigate its cost-effectiveness adds to the originality of the study. The study promises to yield important data, as yet unknown, regarding the effectiveness, cost-effectiveness, implementation issues, and the sustainability of MHFA in the workplace
Computing water flow and storage in complex landscapes
University of Minnesota Ph.D. dissertation. December 2020. Major: Earth Sciences. Advisor: Andrew Wickert. 1 computer file (PDF); ix, 168 pages.Depressions in the landscape can hold water, forming lakes or, on a smaller scale, puddles. Some of these features form long-term water stores, while others are ephemeral, filling and emptying as local weather conditions change. They impact hydrologic connectivity as they either store incoming water, or allow it to pass through them to another portion of the hydrologic system. Surface-water contained in these depressions also interacts with local groundwater. Despite these interactions, many flow-routing algorithms require the complete removal of depressions from a landscape by filling or carving. Resultant flow-routing surfaces can host a continuous, integrated drainage network, but lose information about possible surface-water storage and interruptions to the flow network. I first present an initial answer to this problem: FlowFill, an algorithm that routes a prescribed amount of runoff across the surface in order to flood depressions, but only if enough water is available. FlowFill is useful both in determination of flow-routing surfaces, and in visualisation of changing hydrology through time. I then present Fill-Spill-Merge, a method that rapidly processes and distributes runoff to and through depressions. Fill-Spill-Merge makes use of a depression hierarchy data structure which records information about depressions and their relationships to one another. Fill-Spill-Merge produces appropriate flow-routing surfaces up to 2,600 times faster than FlowFill. Finally, I couple Fill-Spill-Merge with a groundwater module in the Water Table Model. The Water Table Model is capable of computing changes in water table elevation at large spatial scales and over long temporal scales. It incorporates lakes into water table elevation estimates and enables assessments of changing terrestrial water storage through time. I demonstrate an application of the Water Table Model in North Americaâs Great Basin, where a suite of model runs reveals past hydroclimate
The use of remote sensing and GIS in the identification and vulnerability detection of coastal erosion as a hazard in False Bay, South Africa
Thesis (MSc)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Coastal erosion is a worldwide hazard of which the consequences can only be mitigated via
thorough and efficient monitoring of erosion and vulnerability to erosion. This study aimed to
establish the accuracy, efficacy and efficiency of various remote sensing techniques for the
detection and monitoring of coastal erosion and vulnerability occurring in False Bay, South
Africa. There is a need to monitor the erosion in this area as well as to determine the most
effective techniques for monitoring the erosion in False Bay and other similar environments
in the future. This study provides an assessment of the usefulness of different data sources
and techniques for change detection in the coastal environment.
The data sources used were Landsat TM/ETM+ imagery and aerial photographs. Image
differencing, tasselled cap transformations, vegetation index differencing, Boolean change
detection, and post-classification change detection were all performed on the Landsat
imagery. The aerial photographs were assessed using the Digital Shoreline Analysis System
(DSAS) add-on for ArcGIS which determines statistical differences in the shoreline position
as digitised in vector format. The results showed that while the resolution of the Landsat imagery was not sufficient to
analyse erosion along the beach itself, the larger area covered by the satellite images
enabled vulnerability indicators to be seen. Notably, the post-classification change detection
indicated consistent increases in built-up areas, while sand dune, beach, and sand (not
beach) all decreased. NDVI differencing showed consistent decreases in NDVI indicating
decreasing plant health and density. The results of image differencing with both band 4 and
the brightness band led to conclusions that vegetation health was decreasing while reflective
surfaces such as bare sand and roads were increasing. All of these indicate an increased
vulnerability to coastal erosion. The Boolean change detection method was found not to be
useful in this case.
Aerial photographs were studied on four focus areas: Bayview Heights, Macassar Beach,
Strand, and Pringle Bay. The results showed erosion at all four areas, with Strand
experiencing only erosion (no accretion) at an average of 53 cm erosion per year. Erosion at
Macassar Beach and Pringle Bay was also severe, with Bayview Heights being the least
severe and showing a combination of erosion and accretion. The higher resolution available
on the aerial photographs was vital to view changes on the beach itself.
In future studies requiring assessment of changes in the position or condition of the beach
itself, aerial photographs or high resolution satellite data should be used. Studies of
vulnerability extending over the entire coastal zone may make use of Landsat TM images. Post-classification change detection provides powerful change direction information and can
indicate the percentage of area change from one class to another. However, image
differencing and vegetation index differencing are much faster to perform and can provide
information about general trends in the changes occurring. Therefore post-classification
change detection might be used in areas of high and rapid change while image differencing
and vegetation index differencing can be useful to cover vast areas where little change is
expected.AFRIKAANSE OPSOMMING: Kus-erosie is ân wĂȘreldwye gevaar waarvan die gevolge slegs deur deeglike en doeltreffende
monitering van erosie en kwesbaarheid vir erosie verminder kan word. Hierdie studie poog
om die akkuraatheid, doeltreffendheid en effektiwiteit van verskillende afstandswaarneming
tegnieke vas te stel vir die opsporing en monitering van kus-erosie en kwesbaarheid in
Valsbaai, Suid Afrika. Daar is ân behoefte aan die monitering van erosie in hierdie area,
sowel as om die mees doeltreffende tegnieke van die monitering hiervan in Valsbaai en
ander soortgelyke omgewings in die toekoms te bepaal. Hierdie studie bied ân evaluering
van die nut van verskillende data-bronne en tegnieke vir die opsporing van verandering in ân
kusomgewing.
Die data-bronne wat gebruik is, is Landsat TM/ETM+ beelde asook lugfotoâs. Beeld
differensievorming, âtasselled capâ transformasies, plantegroei indeks differensievorming,
Boolse verandering en post-klassifikasie verandering is toegepas op die Landsat beelde. Die
lugfotos is ge-evalueer deur die Digitale Kuslyn Analise Stelsel (Digital Shoreline Analysis
System â DSAS). DSAS is ân bykomstige sagteware vir ArcGIS wat statistiese verskille in
gedigitaliseerde kuslyn posisie bepaal. Die resultate toon dat terwyl die resolusie van die Landsat beelde nie voldoende was om
strand-erosie self te analiseer, die groter area wat deur die satellietbeelde gedek word
toegelaat het om kwesbaarheid aanwysers te ontleed. Spesifiek die post-klassifikasie
verandering het aangedui dat konsekwente toenames in beboude areas voorkom, terwyl
afnames in sandduine, strand en sand-areas voorgekom het. NDVI differensievorming het
konsekwente afnames in NDVI getoon, wat dui op afnames in die gesondheid en digtheid
van plantegroei. Die resultate van die beeld differensievorming met beide Landsat Band 4 en
die helderheid-band het gelei tot die gevolgtrekking dat die gesondheid van plantegroei
afgeneem het, terwyl reflektiewe oppervlaktes soos oop sand en paaie aan die toeneem is.
Al hierdie resultate dui op die verhoogde kwesbaarheid vir kus erosie. Die Boolse
verandering metode is bevind om nie van nut te wees in hierdie geval nie.
Lugfotoâs van vier fokus-areas is bestudeer: Bayview Heights, Macassar Strand, Strand en
Pringlebaai. Resultate van die DSAS analise het gevind dat oorwegend erosie by al vier
areas plaasvind, met Strand die enigste area wat slegs erosie (geen aanwas) ervaar teen ân
gemiddelde koers van 0.53 m per jaar. Erosie by Macassar Strand en Pringlebaai was ook
ernstig, terwyl Bayview Heights die minste erosie ervaar het, met ân kombinasie van erosie
en aanwas. Die hoĂ«r resolusie beskikbaar deur die lugfotoâs was noodsaaklik om
veranderinge in strand areas waar te neem. In toekomstige studies wat die assessering van verandering in die posisie of toestand van
strande noodsaak behoort lugfotos of hoë-resolusie satellietbeeld data gebruik te word.
Studies oor die kwesbaarheid van ân hele kusstreek kan wel gebruik maak van Landsat data.
Post-klassifikasie verandering bied kragtige informasie oor die rigting van verandering en
kan die persentasie van verandering van een klas na ân ander aandui. Beeld en NDVI
differensievorming is egter veel vinniger om uit te voer en kan informasie rakende die
algemene tendense in verandering lewer. Post-klassifikasie verandering kan dus gebruik
word in gebiede van vinnige en beduidende verandering plaasvind, terwyl beeld en NDVI
differensievorming nuttig kan wees om groot areas te dek waar min verandering verwag
word
The use of Landsat and aerial photography for the assessment of coastal erosion and erosion susceptibility in False Bay, South Africa
CITATION: Callaghan, K., Engelbrecht, J. & Kemp, J. 2015. The use of Landsat and aerial photography for the assessment of coastal erosion and erosion susceptibility in False Bay, South Africa. South African Journal of Geomatics, 4(2):65-79.The original publication is available at http://www.sajg.org.zaCoastal erosion is a worldwide hazard, the consequences of which can only be mitigated via
thorough and efficient monitoring of erosion. This study aimed to employ remote sensing techniques
on aerial photographs and Landsat TM/ETM+ imagery for the detection and monitoring of coastal
erosion in False Bay, South Africa. Vegetation change detection as well as post-classification
change detection were performed on the Landsat imagery. Furthermore, aerial photographs were
analysed using the Digital Shoreline Analysis System (DSAS), which determines statistical
differences in shoreline position over time. The results showed that while the resolution of the
Landsat imagery was not sufficient to quantify and analyse erosion along the beach itself, the
larger area covered by the satellite images enabled the identification of changes in landcover
conditions leading to an increased susceptibility to erosion. Notably, the post-classification
change detection indicated consistent increases in built-up areas, while sand dune, beach, and sand
(not beach) decreased. NDVI differencing led to the conclusion that vegetation health was
decreasing while reflective surfaces such as bare sand and roads were increasing. Both of these are
indicative of an increased susceptibility to coastal erosion. Aerial photographs were used for
detailed analysis of four focus areas and results indicated that coastal erosion was taking place
at all four areas. The higher resolution available on the aerial photographs was vital for the
quantification of erosion
and sedimentation rates.http://www.sajg.org.za/index.php/sajg/article/view/233Publisher's versio
An Assessment of the Influence of the Industry Distribution Chain on the Oxygen Levels in Commercial Modified Atmosphere Packaged Cheddar Cheese Using Non-Destructive Oxygen Sensor Technology
The establishment and control of oxygen levels in packs of oxygen-sensitive food products such as cheese is imperative in order to maintain product quality over a determined shelf life. Oxygen sensors quantify oxygen concentrations within packaging using a reversible optical measurement process, and this non-destructive nature ensures the entire supply chain can be monitored and can assist in pinpointing negative issues pertaining to product packaging. This study was carried out in a commercial cheese packaging plant and involved the insertion of 768 sensors into 384 flow-wrapped cheese packs (two sensors per pack) that were flushed with 100% carbon dioxide prior to sealing. The cheese blocks were randomly assigned to two different storage groups to assess the effects of package quality, packaging process efficiency, and handling and distribution on package containment. Results demonstrated that oxygen levels increased in both experimental groups examined over the 30-day assessment period. The group subjected to a simulated industrial distribution route and handling procedures of commercial retailed cheese exhibited the highest level of oxygen detected on every day examined and experienced the highest rate of package failure. The study concluded that fluctuating storage conditions, product movement associated with distribution activities, and the possible presence of cheese-derived contaminants such as calcium lactate crystals were chief contributors to package failure
Impact of a Family History of Hypertension and Physical Activity on Left Ventricular Mass
A positive family history of hypertension (FHH) (+FHH) is associated with elevated left ventricular mass (LVM). Regular physical activity (PA) may eliminate differences in LVM between +FHH and negative family history of hypertension (-FHH) adults. PURPOSE: To determine if a +FHH is associated with a greater LVM compared to a -FHH group within a sample of young, mostly active healthy adults with and without statistically controlling for PA. METHODS: Healthy young (18-32yrs) participants self-reported FHH status and habitual moderate and vigorous PA frequency. Participants then underwent an echocardiogram. RESULTS: Of the 61 participants, 32 (M=11, W=21; non-active=8) reported -FHH and the remaining 29 (M=13, W=16; non-active=2) reported a +FHH. Mann-Whitney tests found the +FHH group had greater LVM (-FHH 129.5±41.8, +FHH 155.2±42.6 g, p=0.015) and LVM/BSA (-FHH 73.5±17.4, +FHH 88.4±17.3 g/m2, p=0.004). Separate ANCOVA models accounting for moderate and vigorous PA found that FHH status independently predicted LVM/BSA and PA frequencies were significant modifiers (ANCOVA controlling moderate PA: FHH status p=0.004, partial η2=0.133; moderate PA p=0.020, partial η2=0.089), (ANCOVA controlling vigorous PA: FHH status p=0.004, partial η2=0.132; vigorous PA p=0.007, partial η2=0.117). CONCLUSION: This analysis suggests that physically active young adults with a +FHH have elevated LVM compared to their -FHH counterparts. This finding is independent of their habitual moderate and vigorous physical activity frequencies
Dorsal and ventral visual stream contributions to preserved reading ability in patients with central alexia
We investigated the role of the left temporo-parietal regions in supporting reading abilities of 23 patients with central alexia (CA). For the behavioural data, we employed principal components analysis (PCA), which identified two components: âreading aloudâ and âreading for meaningâ. Voxel-based morphometry of the PCA results showed an association between reading aloud and grey matter density in the left supramarginal gyrus, part of the dorsal visual stream. By contrast, reading for meaning was associated with a large cluster in the left ventral visual stream, from the collateral sulcus to the anterior temporal pole. Most of the peaks were within the group lesion map, indicating that sparing of these areas results in better preservation of reading ability. However, one white matter (WM) cluster in the medial occipitotemporal lobe was outside the lesioned area. A post-hoc test demonstrated that WM density here was equivalent to controls, suggesting that this was not driven by lesion effects. The two likeliest explanations for this correlation are: 1) that pre-morbid, inter-individual differences in brain structure mitigate the effects of CA; 2) that post-morbid practice-based with reading caused compensatory plasticity. We hope to adjudicate between these explanations with longitudinal therapy data collected in this cohort
Dorsal and ventral visual stream contributions to preserved reading ability in patients with central alexia
We investigated the role of the left temporo-parietal regions in supporting reading abilities of 23 patients with central alexia (CA). For the behavioural data, we employed principal components analysis (PCA), which identified two components: âreading aloudâ and âreading for meaningâ. Voxel-based morphometry of the PCA results showed an association between reading aloud and grey matter density in the left supramarginal gyrus, part of the dorsal visual stream. By contrast, reading for meaning was associated with a large cluster in the left ventral visual stream, from the collateral sulcus to the anterior temporal pole. Most of the peaks were within the group lesion map, indicating that sparing of these areas results in better preservation of reading ability. However, one white matter (WM) cluster in the medial occipitotemporal lobe was outside the lesioned area. A post-hoc test demonstrated that WM density here was equivalent to controls, suggesting that this was not driven by lesion effects. The two likeliest explanations for this correlation are: 1) that pre-morbid, inter-individual differences in brain structure mitigate the effects of CA; 2) that post-morbid practice-based with reading caused compensatory plasticity. We hope to adjudicate between these explanations with longitudinal therapy data collected in this cohort.</p