Transverse magnetic tweezers allowing coincident epi-fluorescence microscopy on horizontally extended DNA

Longitudinal magnetic tweezers (L-MT) have seen wide-scale adoption as the tool-of-choice for stretching and twisting a single DNA molecule. They are also used to probe topological changes in DNA as a result of protein binding and enzymatic activity. However, in the longitudinal configuration, the DNA molecule is extended perpendicular to the imaging plane. As a result, it is only possible to infer biological activity from the motion of the tethered superparamagnetic microsphere. Described here is a “transverse” magnetic tweezers (T-MT) geometry featuring simultaneous control of DNA extension and spatially coincident video-rate epi-fluorescence imaging. Unlike in L-MT, DNA tethers in T-MT are extended parallel to the imaging plane between two micron-sized spheres, and importantly protein targets on the DNA can be localised using fluorescent nanoparticles. The T-MT can manipulate a long DNA construct at molecular extensions approaching the contour length defined by B-DNA helical geometry, and the measured entropic elasticity agrees with the worm-like chain model (force < 35 pN). By incorporating a torsionally constrained DNA tether, the T-MT would allow both the relative extension and twist of the tether to be manipulated, while viewing far-red emitting fluorophore-labelled targets. This T-MT design has the potential to enable the study of DNA binding and remodelling processes under conditions of constant force and defined torsional stress

Corporate accountability in a globalizing environment : empirical evidence

For many years, there have been vigorous arguments between supporters of the shareholder and stakeholder models as to which system is more effective in enhancing corporate values and disciplining managements. What view one takes of course very much depends on political viewpoint and national background. For example. economists or lawyers in the US or UK may argue that the Anglo-American shareholder model is more appropriate. This is because there is at least a criterion (i. e. share price) by which you could measure and compare corporate performance. Supporters of the shareholder model may argue that the concept of stakeholder is anticapitalism and that it is too broad and abstract, providing no clear boundary as to who may or may not fall into that category. Yet in contrast, their Japanese or German (and other Continental European) counterparts may argue that the Anglo-American approach of primarily focusing on share value and wealth maximization is too narrow and an over-simplistic view of the role played by corporations. Supporters of the stakeholder theory would argue that it is necessary to take into consideration interests beyond those of shareholders. This is because businesses ought to demonstrate certain responsibilities towards the society in which they operate. This thesis neither supports nor challenges the validity of either the shareholder or stakeholder approach. Instead it attempts to search for a "middle approach". The aim is to bring the concept of both values together to form a corporate governance model based on convergence and co-existence. The main proposal of this thesis is as follows. Living in the twenty-first century, we must understand that our world is neither being Americanized nor Europeanized or Orientalised. We are instead being globalized. National identities in terms of corporations will become less and less important as multinational corporations extend their activities throughout the globe. With the advance in technology and increase in cross-border business transactions amongst countries, it is no longer justified to argue that "one business model fits all". As academics and practitioners we must therefore explore ways in which we could bring the best out of different models so that they can be converged to form a more coherent approach towards the balancing of different conflicting interests.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

User Perspectives of Mood-Monitoring Apps Available to Young People: Qualitative Content Analysis

Background: Mobile health apps are increasingly available and used in a clinical context to monitor young people’s mood and mental health. Despite the benefits of accessibility and cost-effectiveness, consumer engagement remains a hurdle for uptake and continued use. Hundreds of mood-monitoring apps are publicly available to young people on app stores; however, few studies have examined consumer perspectives. App store reviews held on Google and Apple platforms provide a large, rich source of naturally generated, publicly available user reviews. Although commercial developers use these data to modify and improve their apps, to date, there has been very little in-depth evaluation of app store user reviews within scientific research, and our current understanding of what makes apps engaging and valuable to young people is limited.Objective: This study aims to gain a better understanding of what app users consider useful to encourage frequent and prolonged use of mood-monitoring apps appropriate for young people.Methods: A systematic approach was applied to the selection of apps and reviews. We identified mood-monitoring apps (n=53) by a combination of automated application programming interface (API) methods. We only included apps appropriate for young people based on app store age categories (apps available to those younger than 18 years). We subsequently downloaded all available user reviews via API data scraping methods and selected a representative subsample of reviews (n=1803) for manual qualitative content analysis.Results: The qualitative content analysis revealed 8 main themes: accessibility (34%), flexibility (21%), recording and representation of mood (18%), user requests (17%), reflecting on mood (16%), technical features (16%), design (13%), and health promotion (11%). A total of 6 minor themes were also identified: notification and reminders; recommendation; privacy, security, and transparency; developer; adverts; and social/community.Conclusions: Users value mood-monitoring apps that can be personalized to their needs, have a simple and intuitive design, and allow accurate representation and review of complex and fluctuating moods. App store reviews are a valuable repository of user engagement feedback and provide a wealth of information about what users value in an app and what user needs are not being met. Users perceive mood-monitoring apps positively, but over 20% of reviews identified the need for improvement

Childhood Bullying Victimization, Emotion Regulation, Rumination, Distress Tolerance, and Depressive Symptoms: A Cross-National Examination Among Young Adults In Seven Countries

Existing research suggests a robust association between childhood bullying victimization and depressive symptoms in adulthood, but less is known about potential mediators of this link. Furthermore, there is limited cross-national research evaluating similarities and differences in bullying victimization and its associations with mental health. The current study addressed gaps in the literature by evaluating cognitive and affective responses to stress (i.e., emotion regulation, rumination, and distress tolerance) as potential mediators of the link between recalled bullying victimization and current depressive symptoms among 5909 (70.6% female) college students from seven countries. Results revealed specific indirect associations of bullying victimization through distress tolerance and three out of four facets of rumination, as well as a persistent direct association of childhood bullying on adulthood depression. Emotion regulation strategies were not significantly associated with bullying victimization and did not mediate its association with depressive symptoms. Constrained multigroup models indicated that results were invariant across country and gender. Findings provide evidence of statistical mediation in a cross-sectional sample and await replication in prospective studies. Rumination and distress tolerance may be promising targets for resilience-promoting interventions among children experiencing peer victimization. Ongoing research is needed to clarify cross-national patterns in childhood bullying, identify additional mediators accounting for the remaining direct association, and evaluate emotion regulation as a potential moderator of associations between bullying victimization and adult mental health

The hVPS34-SGK3 pathway counteracts inhibition of the PI3K-Akt to maintain mTORC1 and tumour growth

We explore mechanisms that enable cancer cells to tolerate PI3K or Akt inhibitors. Prolonged treatment of breast cancer cells with PI3K or Akt inhibitors leads to increased expression and activation of a kinase termed SGK3 that is related to Akt. Under these conditions, SGK3 is controlled by hVps34 that generates PtdIns(3)P, which binds to the PX domain of SGK3 promoting phosphorylation and activation by its upstream PDK1 activator. Furthermore, under conditions of prolonged PI3K/Akt pathway inhibition, SGK3 substitutes for Akt by phosphorylating TSC2 to activate mTORC1. We characterise 14h, a compound that inhibits both SGK3 activity and activation in vivo, and show that a combination of Akt and SGK inhibitors induced marked regression of BT‐474 breast cancer cell‐derived tumours in a xenograft model. Finally, we present the kinome‐wide analysis of mRNA expression dynamics induced by PI3K/Akt inhibition. Our findings highlight the importance of the hVps34‐SGK3 pathway and suggest it represents a mechanism to counteract inhibition of PI3K/Akt signalling. The data support the potential of targeting both Akt and SGK as a cancer therapeutic

Identification of Pharmacodynamic Transcript Biomarkers in Response to FGFR Inhibition by AZD4547

The challenge of developing effective pharmacodynamic biomarkers for preclinical and clinical testing of FGFR signaling inhibition is significant. Assays that rely on the measurement of phospho-protein epitopes can be limited by the availability of effective antibody detection reagents. Transcript profiling enables accurate quantification of many biomarkers and provides a broader representation of pathway modulation. To identify dynamic transcript biomarkers of FGFR signaling inhibition by AZD4547, a potent inhibitor of FGF receptors 1, 2, and 3, a gene expression profiling study was performed in FGFR2-amplified, drug-sensitive tumor cell lines. Consistent with known signaling pathways activated by FGFR, we identified transcript biomarkers downstream of the RAS-MAPK and PI3K/AKT pathways. Using different tumor cell lines in vitro and xenografts in vivo, we confirmed that some of these transcript biomarkers (DUSP6, ETV5, YPEL2) were modulated downstream of oncogenic FGFR1, 2, 3, whereas others showed selective modulation only by FGFR2 signaling (EGR1). These transcripts showed consistent time-dependent modulation, corresponding to the plasma exposure of AZD4547 and inhibition of phosphorylation of the downstream signaling molecules FRS2 or ERK. Combination of FGFR and AKT inhibition in an FGFR2-mutated endometrial cancer xenograft model enhanced modulation of transcript biomarkers from the PI3K/AKT pathway and tumor growth inhibition. These biomarkers were detected on the clinically validated nanoString platform. Taken together, these data identified novel dynamic transcript biomarkers of FGFR inhibition that were validated in a number of in vivo models, and which are more robustly modulated by FGFR inhibition than some conventional downstream signaling protein biomarkers

Dehydropolymerization of Amine-Boranes using Bis(imino)pyridine Rhodium Pre-Catalysis: σ-Amine-Borane Complexes, Nanoparticles, and Low Residual-Metal BN-Polymers that can be Chemically Repurposed.

The sigma amine-borane complexes [Rh(L1)(h2:h2H3B·NRH2)][OTf] (L1 = 2,6-bis-[1-(2,6-diisopropylphenylimino)ethyl]pyridine, R = Me, Et, nPr) are described, alongside [Rh(L1)(NMeH2)][OTf]. Using R = Me as the pre-catalyst (1 mol%) the dehydropolymerization of H3B·NMeH2 gives [H2BNMeH]n selectively. Added NMeH2, or the direct use of [Rh(L1)(NMeH2)][OTf], is required for initiation of catalysis, which is suggested to operate through formation of a neutral hydride complex, Rh(L1)H. The formation of small (1-5 nm) nanoparticles is observed during catalysis, but studies are ambiguous as to whether the catalysis is solely nanoparticle promoted or if there is a molecular homogeneous component. [Rh(L1)(NMeH2)][OTf] is shown to operate at 0.025 mol% loadings on a 2 g scale to give polyaminoborane [H2BNMeH]n [Mn = 30,900 g/mol, Ð = 1.8] that can be purified to a low residual [Rh] (6 µg/g). Addition of Na[N(SiMe3)2] to [H2BNMeH]n results in selective depolymerization to form the eee-isomer of N,N,N-trimethylborazane [H2BNMeH]3: the chemical repurposing of a main-group polymer

The association of negative mood with automatic and effortful facial expression mimicry

The natural process of mimicking the facial expressions of others is well established, as are the deficits in this reflexive behavior for individuals with clinical disorders such as depression. This study examines the extent of this deficit in non-clinical individuals with high transient negative mood, and whether it extends to both automatic and effortful emotion expression behavior. One hundred and thirty-six participants were shown happy, sad, and neutral faces, while electromyography (EMG) recorded facial muscle responses. Automatic (reflexive) mimicry was assessed while participants simply viewed facially expressive photographs, while effortful mimicry was monitored when individuals were told to intentionally copy the expressions in the photographs. Results indicated that high levels of negative mood were primarily associated with deficits in effortful mimicry of happy expressions, although some similar evidence was found in automatic mimicry of happy faces. Surprisingly, there were also ties between negative moods and inaccuracies in effortful mimicry of sad expressions (but not automatic mimicry). Inaccurate automatic and effortful mimicry were also tied with lower self-reported social support and greater loneliness. These results indicate that even in healthy individuals, transient and minor changes in negative mood are tied to deficiencies in facial mimicry at both the automatic and effortful level