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Polyplex Particles Based on Comb-Like Polyethylenimine/Poly(2-ethyl-2-oxazoline) Copolymers: Relating Biological Performance with Morphology and Structure
No full textThe present contribution is focused on feasibility of using comb-like copolymers of polyethylenimine with poly(2-ethyl-2-oxazoline) (LPEI-comb-PEtOx) with varying grafting densities and degrees of polymerization of PEI and PEtOx to deliver DNA molecules into cells. The copolymers form small and well-defined particles at elevated temperatures, which are used as platforms for binding and condensing DNA. The electrostatic interactions between particles and DNA result in formation of sub-100 nm polyplex particles of narrow size distribution and different morphology and structure. The investigated gene delivery systems exhibit transfection efficiency dependent on the copolymer chain topology, shape of the polyplex particles, and internalization pathway. Flow cytometry shows enhanced transfection efficiency of the polyplexes with elongated and ellipsoidal morphology. The preliminary biocompatibility study on a panel of human cell lines shows that pure copolymers and polyplexes thereof are practically devoid of cytotoxicity
Temporal dynamics of social and affective decision-making processes
No full textThis thesis will establish the influence of social saliency and affect on perceptual decision-making. Although the study of the neural basis of human decision-making has inspired great attention, much of the literature has employed fMRI to explore complex decision-making in the brain which has great advantages in providing spatial information about the underlying neural activation. But, there is a lack of studies on the temporal dynamics of simple perceptual decision-making. It is important to focus on simple perceptual decision-making because people tend to make decisions rapidly based on the presented information which varies in sociality. However, despite research that has highlighted the importance of social saliency in simple perceptual decision-making tasks (Gutnik et al., 2006) the influence of social saliency on the temporal dynamics is understudied. It is crucial to examine the influence of social saliency on decision-making because humans are bombarded with various socially salient information/stimuli which impacts subsequent behaviour. Another influence on decision-making is the affective nature of information/stimuli. Emotions are the dominant driver of the most meaningful decisions in life (Keltner & Lerner 2010; Keltner et al 2014) but the impact of affect on the temporal dynamics of simple perceptual decision-making tasks, in particular, remains to be established.The current thesis addressed those gaps in the literature by examining the influence of social saliency and affect on the temporal dynamics of simple perceptual decision-making. Three conceptually similar studies were designed involving simple perceptual decision-making tasks in which social saliency (e.g. task stimuli, word primes and context) and affect (e.g. positive and negative) were manipulated to contrast differences in amplitudes in certain processing stages dependent on social saliency and affect. The first study was a systematic review which synthesised existing neurophysiological evidence from studies that manipulated social saliency across different neuroimaging paradigms and task designs. The systematic review highlighted the scarcity of temporal examination of the influence of social saliency on decision-making and the limited use of simple perceptual decision-making tasks in that literature.The second study investigated the influence of social saliency of task stimuli on behavioural performance and temporal dynamics in a preference choice task involving two conditions: 1) choosing between faces that varied in affect - social condition and 2) choosing between landscapes that varied in affect – non-social condition. In both conditions, one happy and one sad image was presented in a pair. Results demonstrated that the sensory processing and attentional focus stages had higher amplitudes for faces, whereas the affective evaluation stage was sensitive to landscapes. During the late processing stage,social saliency did not influence the decision-related stage (i.e. there was no difference in processing based on social saliency).The third study investigated the impact of social saliency on unconscious influences using a simple perceptual decision-making task involving trustworthiness ratings about neutral faces in two conditions: 1) primed with social words and 2) primed with non-social words. To examine the contributions of affect on decision-making, in both conditions word primes varied in affective nature (positive and negative). Social saliency and affect influenced behavioural performance and trustworthiness ratings of neutral faces: reaction times were faster in trials preceded by non-social primes than social word primes and faces preceded by social word primes were rated as more trustworthy compared to non-social word primes. There was no effect of social saliency on temporal dynamics, but negatively-valenced words elicited higher ERP amplitudes during the affective evaluation and decision-related stages.The fourth study moved from manipulating the social saliency and affective nature of the task stimuli and word primes to manipulating the social context. The influence of social context on the temporal dynamics of performance monitoring was investigated while participants performed a visual discrimination task in two conditions: 1) in the presence of a passive observer – social condition and 2) alone – non-social condition. The influence of affect was examined by giving participants performance feedback (i.e. via the computer) that varied in affect (i.e. neutral, negative and positive). The findings revealed an effect of social saliency at the behavioural level: reaction times were faster during the non-social condition compared to the social condition. There was no effect of social saliency on temporal dynamics, but negative and neutral feedback elicited higher ERP amplitudes during the feedback-related stage and the mid-range stage. There was an interaction between social saliency and affect with higher amplitudes for non-social trials where negative feedback was given during the mid-range stages.Overall, the current thesis contributes to the literature by providing electrophysiological evidence that both social saliency and affect of stimuli or feedback moderate the process of decision-making at different stages depending on the type of stimuli and task used. Early components (less than <200ms after stimulus onset) are sensitive to the social saliency, but this effect is stimuli dependent: faces as a form of social stimuli demonstrated an influence on early temporal dynamics. Mid-range and late components (around 300-600ms) are sensitive to non-social information and modulated by the affect of stimuli/feedback with sensitivity towards negatively-valenced stimuli. Finally, the electrophysiological findings show that when social saliency interacts with affect, it elicits greater ERP amplitudes (i.e. activation) during the later processing stages that decision-making evaluative judgements take place
A three-year epidemiological prospective cohort study of rugby league match injuries from the European Super League
No full textObjectives:Conduct a comprehensive epidemiological study of match injury characteristics (incidence, severity, causes, diagnostics, and temporal trends) in professional rugby league.Design:Prospective cohort design.Methods:Data was captured over the 2013, '14, and '15 seasons, collected via an online-reporting survey tool, and underpinned by nominal group technique-agreed definitions. Injury details were provided by club medical staff in accordance to the survey fields from all European Super League teams (e.g. injury occurrence/return dates, diagnosis, mechanism, recurrence). All time-loss injuries have been reported.Results:Injury incidence of 57 injuries/1000h has been observed over the three-year period, with an average of 34days missed per injury. The final 20-min period was the most significant period for injury occurrence, and higher incidence of injury/1000h played was during the start of the season in February, although an absolute injury risk for injury frequency was shown in April due to the greatest playing time. Forward positions reported the highest injury incidence whilst tackle activities were the most frequent mechanism of injury. Concussions and hamstring strains (5 injuries/1000h) were the most commonly diagnosed injuries, although the knee joint region (10 injuries/1000h) was the most frequently injured area.Conclusions:In light of the most common injury diagnoses, mechanisms, identified seasonal risk, and time of match, the data should look to inform player preparation in terms of physical conditioning and tackle technique in order to optimise player welfare and availability for participation
Parenting an adolescent with a new diagnosis of type 1 diabetes: a parent’s perspective
No full textParenting a teenager is not easy, but the challenge is increased when he or she has type 1 diabetes. Here, the mother of a boy with type 1 diabetes describes her and her family’s experiences in the period leading up to her son’s diagnosis and how their lives have changed as a result. She makes a number of suggestions about how awareness of symptoms can be raised and how patients and their families can be supported to achieve the best outcomes
Enhancing the student journey: Let's LEAP Online!
No full textThe session will discuss the background to the development of LEAP Online as an academic skills portal by one of the content developers. The programme and module leads will discuss the introduction of LEAP Online as a study aid, positively reinforcing the tool throughout the students’ programmes of study. The student viewpoint of how LEAP Online has provided the skills, knowledge and confidence to enhance progress in all academic areas will be outlined from a current student’s perspective.It is anticipated that attendees will gain the knowledge of how using LEAP Online in teaching can have a transformative effect on the student learning journey
First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements
No full textElectronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA -> B) or the N (IIA -> N) atom. For IIA -> B, a shallow accept level degenerated into valence band (VB); while for IIA ! N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe -> N and IIMg -> N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants' radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant. (c) 2018 Author(s)
