227 research outputs found

    Groundwater Irrigation System for Sustainable Agriculture

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    The aim of this project was to develop a prototype that may be a model to help relieve food insecurity in rural Liberia. This was accomplished by designing a groundwater extraction, recharge, and irrigation system to facilitate year-long crop-growth. The project was in partnership with BRAID Africa and a community in Zwedru, located in east Liberia, near the border of Côte D’Ivoire. During 2010 and 2011, a civil war broke out in Côte D’Ivoire and led to the citizens of the country taking refuge in Liberia (Leaf 2015). Many refugees have decided to stay in Liberia and are struggling to maintain food security as most subsist on rice with not even enough to sell. Currently, villagers in Zwedru only grow the rice in swamps during the rainy season and, with climate change, the rainy season is becoming increasingly unreliable (USAID 2012). The irrigation system that was designed for this project has allowed villagers to grow certain crops, such as cassava, okra, chard, and squash, during the dry season which will help alleviate food insecurity with the goal of providing a source of income for the farmers. This project was designed for a one hectare (2.47 acres) plot, which can be scaled up or down depending on land area and available resources

    Pearse Hutchinson New Collections at Special Collections & Archives Maynooth University Library

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    In late 2013 agreement was reached with the estate of the renowned writer Pearse Hutchinson to permanently deposit his archive in the Library at Maynooth Universi-ty. While this will lead to a variety of provisions, such as an annual bursary and colloquia, at the centre of the whole project is the archival collection, in breadth and content, every bit as extraordinary as the man

    The effect of mean pore size in collagen-glycosaminoglycan scaffolds on cell migration and differentiation for bone tissue engineering applications

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    Tissue engineering was born from the belief that primary cells could be isolated from a patient, expanded in vitro and seeded onto a substrate that could be grafted back into the patient (Yang et a/, 2001) providing a biological alternative to transplantations and prosthesis. There are three main components in tissue engineering, scaffolds, cells and signalling mechanisms that make up the tissue engineering triad. This thesis focuses on the interplay between cell behaviour and scaffold structural properties. Recent studies from our laboratory have developed novel freeze-drying techniques to vary the structure of collagen-glycosaminoglycan (GAG) scaffolds producing scaffolds with mean pores ranging from 85 pm - 325 pm (Haugh et a/, 2010). The general aim of this thesis was to investigate, using this range of scaffolds, the effect of mean pore size on cell behaviour in the scaffolds and see how this behaviour varies with different cell types. A non-linear effect was seen on initial cell attachment but ultimately scaffolds with the largest pores size of 325 pm facilitated optimal osteoblast attachment, proliferation and migration. A comparison of stem cell (MSC) behaviour to semi-differentiated osteoblasts in the scaffolds demonstrated a similar non-linear effect on cell attachment but poorer MSC migration was observed highlighting the difference in cell type behaviour. Further analysis shed some light on this effect whereby MSCs were physically bigger cells and less motile. Longer term studies were carried out to determine the effect of mean pore size on osteoblast differentiation, matrix mineralisation and cell-mediated contraction. The largest scaffold mean pore size of 325 pm facilitated improved cell distribution, an earlier onset of osteogenic differentiation and a higher level of mineralisation. The final study of this thesis investigated the potential of human amniotic fluid derived stem cells as a readily accessible source of pluripotent stem cells (AFSCs). These cells demonstrated osteogenic differentiation and an ability to attach to the collagen-GAG scaffold. In conclusion, mean pore size was shown to have an effect on cell behaviour in collagen-GAG scaffolds. Ultimately the larger pores of 325 pm facilitate optimal cell attachment, migration, osteogenic differentiation, matrix mineralisation and cellmediated contraction. In addition, the osteogenic potential of a readily accessible source of pluripotent stem cells has demonstrated their future potential in bone tissue engineering

    Twenty years of load theory—Where are we now, and where should we go next?

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    Selective attention allows us to ignore what is task-irrelevant and focus on what is task-relevant. The cognitive and neural mechanisms that underlie this process are key topics of investigation in cognitive psychology. One of the more prominent theories of attention is perceptual load theory, which suggests that the efficiency of selective attention is dependent on both perceptual and cognitive load. It is now more than 20 years since the proposal of load theory, and it is a good time to evaluate the evidence in support of this influential model. The present article supplements and extends previous reviews (Lavie, Trends in Cognitive Sciences, 9, 75–82. doi:10.​1016/​j.​tics.​2004.​12.​004, 2005, Current Directions in Psychological Science, 19, 143–148. doi:10.​1177/​0963721410370295​, 2010) by examining more recent research in what appears to be a rapidly expanding area. The article comprises five parts, examining (1) evidence for the effects of perceptual load on attention, (2) cognitive load, (3) individual differences under load, (4) alternative theories and criticisms, and (5) the future of load theory. We argue that the key next step for load theory will be the application of the model to real-world tasks. The potential benefits of applied attention research are numerous, and there is tentative evidence that applied research would provide strong support for the theory itself, as well as real-world benefits related to activities in which attention is crucial, such as driving and education

    Novel freeze-drying methods to produce a range of collagen-glycosaminoglycan scaffolds with tailored mean pore sizes.

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    The pore structure of three-dimensional scaffolds used in tissue engineering has been shown to significantly influence cellular activity. As the optimal pore size is dependant on the specifics of the tissue engineering application, the ability to alter the pore size over a wide range is essential for a particular scaffold to be suitable for multiple applications. With this in mind, the aim of this study was to develop methodologies to produce a range of collagen-glycosaminoglycan (CG) scaffolds with tailored mean pore sizes. The pore size of CG scaffolds is established during the freeze-drying fabrication process. In this study, freezing temperature was varied (−10 degrees C to −70 degrees C) and an annealing step was introduced to the process to determine their effects on pore size. Annealing is an additional step in the freeze-drying cycle that involves raising the temperature of the frozen suspension to increase the rate of ice crystal growth. The results show that the pore size of the scaffolds decreased as the freezing temperature was reduced. Additionally, the introduction of an annealing step during freeze-drying was found to result in a significant increase (40%) in pore size. Taken together, these results demonstrate that the methodologies developed in this study can be used to produce a range of CG scaffolds with mean pore sizes from 85 to 325 microm. This is a substantial improvement on the range of pore sizes that were possible to produce previously (96-150 microm). The methods developed in this study provide a basis for the investigation of the effects of pore size on both in vitro and in vivo performance and for the determination of the optimal pore structure for specific tissue engineering applications

    The impact of COVID-19 on the physical activity and sedentary behaviour levels of pregnant women with gestational diabetes

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    BackgroundThe aim of this study was to understand how physical activity and sedentary behaviour levels of pregnant women with gestational diabetes in the UK have been affected by COVID-19.MethodsAn online survey exploring physical activity and sedentary behaviour levels of pregnant women with gestational diabetes during COVID-19 was distributed through social media platforms. Women who had been pregnant during the COVID-19 outbreak and had gestational diabetes, were resident in the UK, were 18 years old or over and could understand written English were invited to take part.ResultsA total of 724 women accessed the survey, 553 of these met the eligibility criteria and took part in the survey. Sedentary time increased for 79% of the women during the pandemic. Almost half of the women (47%) were meeting the physical activity guidelines pre COVID-19 during their pregnancy, this dropped to 23% during the COVID-19 pandemic. Fear of leaving the house due to COVID-19 was the most commonly reported reason for the decline. Significant associations were found between meeting the physical activity guidelines during COVID-19 and educational attainment, fitness equipment ownership and knowledge of how to exercise safely in pregnancy.Conclusions and implicationsThese results show the impact of COVID-19 on physical activity and sedentary behaviour levels and highlight the need for targeted public health initiatives as the pandemic continues and for future lockdowns. Women with gestational diabetes need to know how it is safe and beneficial to them to engage in physical activity and ways to do this from their homes if fear of leaving the house due to COVID-19 is a barrier for them. Online physical activity classes provided by certified trainers in physical activity for pregnant women may help them remain active when face-to-face appointments are reduced and limited additional resources are available

    See, Like, Share, Remember: Adolescents’ Responses to Unhealthy-, Healthy- and Non-Food Advertising in Social Media

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    Media-saturated digital environments seek to influence social media users’ behaviour, including through marketing. The World Health Organization has identified food marketing, including advertising for unhealthy items, as detrimental to health, and in many countries, regulation restricts such marketing and advertising to younger children. Yet regulation rarely addresses adolescents and few studies have examined their responses to social media advertising. In two studies, we examined adolescents’ attention, memory and social responses to advertising posts, including interactions between product types and source of posts. We hypothesized adolescents would respond more positively to unhealthy food advertising compared to healthy food or non-food advertising, and more positively to ads shared by peers or celebrities than to ads shared by a brand. Outcomes measured were (1a) social responses (likelihood to ‘share’, attitude to peer); (1b) brand memory (recall, recognition) and (2) attention (eye-tracking fixation duration and count). Participants were 151 adolescent social media users (Study 1: n = 72; 13−14 years; M = 13.56 years, SD = 0.5; Study 2: n = 79, 13−17 years, M = 15.37 years, SD = 1.351). They viewed 36 fictitious Facebook profile feeds created to show age-typical content. In a 3 × 3 factorial design, each contained an advertising post that varied by content (healthy/unhealthy/non-food) and source (peer/celebrity/company). Generalised linear mixed models showed that advertisements for unhealthy food evoked significantly more positive responses, compared to non-food and healthy food, on 5 of 6 measures: adolescents were more likely to wish to ‘share’ unhealthy posts; rated peers more positively when they had unhealthy posts in their feeds; recalled and recognised a greater number of unhealthy food brands; and viewed unhealthy advertising posts for longer. Interactions with sources (peers, celebrities and companies) were more complex but also favoured unhealthy food advertising. Implications are that regulation of unhealthy food advertising should address adolescents and digital media

    Inhibition of Burkholderia Multivorans Adhesion to Lung Epithelial Cells by Bivalent Lactosides

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    Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a real-time PCR method to quantify the levels of binding of B. multivorans to the lung epithelial cells, we have examined glycoconjugate derivatives for their potential to inhibit host cell attachment. Bivalent lactosides previously shown to inhibit galectin binding significantly reduced the attachment of B. multivorans to CF lung epithelial cells at micromolar concentrations. This was in contrast to monosaccharides and lactose, which were only effective in the millimolar range. Development of glycoconjugate therapies such as these, which inhibit attachment to lung epithelial cells, represent an alternative means of preventing infection with inherently antimicrobially resistant pathogens such as B. multivorans
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