12,407 research outputs found

    The developing maternal-infant relationship: a qualitative longitudinal study

    Get PDF
    Aim The study aimed to explore maternal perceptions and the use of knowledge relating to their infant’s mental health over time using qualitative longitudinal research. Background There has been a growing interest in infant mental health over recent years. Much of this interest is directed through the lens of infant determinism, through knowledge regarding neurological development resulting in biological determinism. Research and policy in this field are directed toward individual parenting behaviours, usually focused on the mother. Despite this, there is little attention given to maternal perspectives of infant mental health, indicating that a more innovative approach to methodology is required. Methods This study took a qualitative longitudinal approach, and interviews were undertaken with seven mothers from the third trimester of pregnancy and then throughout the first year of the infant’s life. Interviews were conducted at 34 weeks of pregnancy, and then when the infant was 6 and 12 weeks, 6, 9, and 12 months, alongside the collection of researcher field notes—a total of 41 interviews. Data were analysed by creating case profiles, memos, and summaries, and then cross-comparison of the emerging narratives. A psycho-socially informed approach was taken to the analysis of data. Findings Three interrelated themes emerged from the data: evolving maternal identity, growing a person, and creating a safe space. The theme of evolving maternal identity dominated the other themes of growing a person and creating a safe space in a way that met perceived socio-cultural requirements for mothering and childcare practices. Participants’ personal stories give voice to their perceptions of the developing maternal-infant relationship in the context of their socio-cultural setting, relationships with others, and experiences over time. Conclusions This study adds new knowledge by giving mothers a voice to express how the maternal-infant relationship develops over time. The findings demonstrate how the developing maternal-infant relationship grows in response to their mutual needs as the mother works to create and sustain identities for herself and the infant that will fit within their socio-cultural context and individual situations. Additionally, the findings illustrate the importance of temporal considerations, social networks, and intergenerational relationships to this evolving process. Recommendations for practice, policy, and education are made that reflect the unique relationship between mother and infant and the need to conceptualise this using an ecological approach

    Investigating the mechanism of human beta defensin-2-mediated protection of skin barrier in vitro

    Get PDF
    The human skin barrier is a biological imperative. Chronic inflammatory skin diseases, such as Atopic Dermatitis (AD), are characterised by a reduction in skin barrier function and an increased number of secondary infections. Staphyloccocus aureus (S. aureus) has an increased presence on AD lesional skin and contributes significantly to AD pathology. It was previously demonstrated that the damage induced by a virulence factor of S. aureus, V8 protease, which causes further breakdown in skin barrier function, can be reduced by induction of human β- defensin (HBD)2 (by IL-1β) or exogenous HBD2 application. Induction of this defensin is impaired in AD skin. This thesis examines the mechanism of HBD2-mediated barrier protection in vitro; demonstrating that in this system, HBD2 was not providing protection through direct protease inhibition, nor was it altering keratinocyte proliferation or migration, or exhibiting specific localisation within the monolayer. Proteomics data demonstrated that HBD2 did not induce expression of known antiproteases but suggested that HBD2 stimulation may function by modulating expression of extracellular matrix proteins, specifically collagen- IVα2 and Laminin-β-1. Alternative pathways of protection initiated by IL-1β and TNFα stimulation were also investigated, as well as their influence over generalised wound healing. Finally, novel 3D human skin epidermal models were used to better recapitulate the structure of human epidermis and examine alterations to skin barrier function in a more physiological system. These data validate the barrier-protective properties of HBD2 and extended our knowledge of the consequences of exposure to this peptide in this context

    Exploring Employees\u27 Perceptions of the Learning Organization and Their Learning Experiences in a Georgia State Government Agency – A Concurrent Mixed Methods Study

    Get PDF
    This concurrent Mixed Methods (MM) research study explored employee learning perceptions and experiences in a state of Georgia government agency. The study used the Dimension of the Learning Organization Questionnaire (DLOQ) to examine employee perceptions of a learning organization across management levels and tenure. It also used semi-structured phenomenological interviews to examine learning experiences. The two questions that framed the study were: (1) How do employees navigate learning individually, in teams, and organizationally? (2) How do employee perceptions of the learning organization compare based on tenure and management level? The concurrent mixed methods design allowed for comparison of findings from the questionnaire and the interviews. Participants were simultaneously recruited from the same state of Georgia government agency to complete the questionnaire and interview voluntarily. Three hundred and thirty-eight (338) employees responded to the questionnaire, the quantitative (QUAN) strand. Five (5) employees participated in the interviews, the qualitative (QUAL) strand. The interview data was analyzed using a hybrid/eclectic methodology of coding, theming, and analytic memos. The questionnaire data was analyzed using descriptive and non-parametric statistical tests. The findings of the study suggest that leadership influences learning critically. For this organization to continue learning and growing, it must focus on the leaderships’ impact on its employees\u27 learning in the work environment. Additionally, significant differences in employee perceptions of the learning organization were observed. These differences were between employees with 6 to 10 years and those with 16 to 20 years of tenure on Inquiry/Dialogue (Dimension 2), Organization Environment Connection (Dimension 6), and Individual Level learning (Level 1). While the findings present possible explanations for the differing perceptions, future research should examine this further

    A Non-intrusive Approach for Physics-constrained Learning with Application to Fuel Cell Modeling

    Full text link
    A data-driven model augmentation framework, referred to as Weakly-coupled Integrated Inference and Machine Learning (IIML), is presented to improve the predictive accuracy of physical models. In contrast to parameter calibration, this work seeks corrections to the structure of the model by a) inferring augmentation fields that are consistent with the underlying model, and b) transforming these fields into corrective model forms. The proposed approach couples the inference and learning steps in a weak sense via an alternating optimization approach. This coupling ensures that the augmentation fields remain learnable and maintain consistent functional relationships with local modeled quantities across the training dataset. An iterative solution procedure is presented in this paper, removing the need to embed the augmentation function during the inference process. This framework is used to infer an augmentation introduced within a Polymer electrolyte membrane fuel cell (PEMFC) model using a small amount of training data (from only 14 training cases.) These training cases belong to a dataset consisting of high-fidelity simulation data obtained from a high-fidelity model of a first generation Toyota Mirai. All cases in this dataset are characterized by different inflow and outflow conditions on the same geometry. When tested on 1224 different configurations, the inferred augmentation significantly improves the predictive accuracy for a wide range of physical conditions. Predictions and available data for the current density distribution are also compared to demonstrate the predictive capability of the model for quantities of interest which were not involved in the inference process. The results demonstrate that the weakly-coupled IIML framework offers sophisticated and robust model augmentation capabilities without requiring extensive changes to the numerical solver

    Industrial Robotics for Advanced Machining

    Get PDF
    This work presents a literature review of the current state of robotic machining with industrial machining robots, primarily those with 6-axis end effectors and serial link (anthropomorphic) construction. Various disadvantages of robotic machining in industry are presented, as well as the methods applied to mitigate them and discussions of their effects. From this review, the methods of dynamic modelling, stability prediction and configuration control are selected for application to the task of optimisation of a robotic machining cell for drilling operations. Matrix Structural Analysis (MSA) and methods developed by Klimchik et al. are used for compliance modelling, stability prediction methods developed by Altintas et al. and machining stability lobe prediction are then applied to a robotic drilling process, as explored by Mousavi et al. This optimisation method is applied using the measured and estimated properties of an ABB IRB 6640 robot and results are presented in comparison with previous experimentation with the physical robot, and analytical stability predictions from the same cutting parameters with Cutpro software. Results are discussed in the concluding chapters, as well as discontinued parts of the project and suggestions for future work

    Investigating the role of R2TP-like co-chaperone complexes during axonemal dynein assembly

    Get PDF
    Motile cilia are specialised cell-types which in humans have important roles in the linings of the airways, the reproductive system and the brain. The movement, required for this type of cilia to function, is facilitated by structures called axonemal dynein motor complexes. These are large, multi-subunit structures, and so it is crucial that they are assembled correctly. In humans, if the motility of these is defective, it can lead to a disorder called Primary Ciliary Dyskinesia, or PCD. This is a heterogeneous, autosomal recessive disorder – symptoms of which include abnormally positioned organs, chronic respiratory infections and infertility. Therefore, the development and structure of the motile cilia is tightly regulated by multiple proteins including chaperones, dynein axonemal assembly factors (DNAAFs), microtubule inner proteins (MIPs), the outer arm docking complex (ODA-DC) and the nexin-dynein regulatory complex (N-DRC). Chaperones work with co-chaperones to regulate their many functions within the cell. One of these co-chaperones is the R2TP complex, which was originally discovered in yeast but is conserved in higher organisms. This multi-protein co-chaperone is involved in the assembly of multi-subunit complexes such as the axonemal dynein motors. Two of the R2TP subunits, Pontin and Reptin, are involved in many cellular functions both in this co-chaperone complex and independently. It is thought that as some DNAAFs share similar protein domains to the components of the R2TP complex, they may form R2TP-like complexes. However, the specific details surrounding the roles of these complexes during the assembly process remains unclear. The structure of motile cilia is highly conserved throughout evolution and Drosophila melanogaster has been shown previously to be an excellent model for furthering understanding into the development and function of these structures as only two cell types in the fly contain axonemal dynein motor complexes. These are the chordotonal neuron, which has a motile ciliated dendrite essential for its mechanosensory function, and the sperm flagellum. In this thesis, I use the Drosophila model to further characterise putative ciliary genes (Wdr16 and Dpcd) identified by a transcriptome analysis previously carried out in the lab. RNAi knockdown experiments as well as expression analysis supported motile cilia functions. The diversity which has been identified regarding the roles of these two putative ciliary genes highlights how proteins can be involved in motile cilia in different ways. I also use this genetically tractable model to further understand the roles of the individual proteins of a previously identified R2TP-like complex (R2DP3). Electron microscopy, proteomics and investigation into how the localisation of dynein subsets was affected in null mutants (generated using CRISPR/Cas9) allowed for the role of this R2TP-like complex in the dynein assembly process to be further specified. Using co-immunoprecipitation and affinity purification, we identified an additional protein complex featuring Pontin and Reptin of the R2TP complex, alongside the DNAAF Heatr2 and the putative DNAAF Dpcd. As well as a role in dynein assembly, both DNAAFs are additionally expressed in the neuroblasts of the CNS, and disruption to their function results in a late larval lethality. Therefore, we have found these genes to not be specific to the dynein assembly process and hypothesise that Dpcd may have an additional function (working with Pontin, Reptin and potentially Heatr2) in the regulation of AKT signalling and therefore impact cell proliferation
    • …
    corecore