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Preimplantation genetic testing for aneuploidy ‘rescues’ poor-quality blastocysts and increases embryo availability for transfer: a 9-year single centre analysis
No full textResearch Question: Does preimplantation genetic testing for aneuploidy (PGT-A) and the transfer of euploid poor-quality blastocysts (PQBs) reduce the number of transfers needed to achieve live births in comparison to the transfer of their untested counterparts?
Design: Single-centre retrospective cohort study included 7,332 PGT-A blastocysts obtained from 2,258 cycles across 1,344 patients between 2015 and 2024. Transfer outcomes were analysed for a subset of 74 cycles involving tested PQBs from 69 patients and compared with 192 cycles involving untested PQBs from 180 patients during the same period.
Results: High-quality blastocysts (HQBs; AA, AB, BA, and BB) were most likely to be euploid, while poor-quality blastocysts (PQBs; CC, DC, CD, and DD) were more likely to be aneuploid. Embryos that reached the blastocyst stage by day 5 had a higher likelihood of being euploid. Among transferred PQBs, PGT-A did not significantly impact the pregnancy rate (33.3% vs. 23.4%); however, the miscarriage rate was significantly lower in the PGT-A-tested group (13.6% vs 51.2%). The number of live births was higher in the PGT-A group (26.4 % vs 11.1%) and with the transfer of day 5 frozen blastocysts. Notably, live births were also observed from blastocysts with the poorest expansion and morphology scores. Analysis of live births revealed no significant differences in gestational age or birthweight between the PGT-A and untested groups.
Conclusions: A clinically relevant proportion of PQBs are euploid, PQBs can result in live births and euploid transfer is associated with lower miscarriage rates. In combination, this suggests that PQBs should not be routinely discarded, particularly if they are prior-tested using PGT-A
Systematic study of temperature dependent spectral properties of solid methanol
Get PDFThis thesis investigates the structure of solid-phase methanol under laboratory-simulated space environments, with particular focusing on how the deposition temperature and interactions with water molecules influence its spectroscopic properties. The motivation for this study arises from a critical gap in the fundamental understanding of vapour-deposited solid methanol. Methanol ice, which is abundant in space and recognised as a precursor to the formation of more complex organic molecules, has been the subject of numerous astrochemical studies. However, despite extensive astrochemical studies on methanol ice formation, reactivity, and desorption, the structural properties of vapour-deposited solid methanol remain poorly constrained. In particular, inconsistent deposition and annealing strategies across studies have led to conflicting reports of its phase transition temperature, hindering reliable interpretation of observational spectra. In light of this, a better understanding of solid methanol’s structure and properties under different deposition conditions is needed, particularly to interpret high-resolution observational spectra from instruments such as James Webb Space Telescope (JWST), which enable more detailed studies of distribution, abundance and properties of solid methanol in space.
The aim of this work is to provide a deeper insight into how deposition temperature affects methanol structure. It also investigates how different types of interactions with water molecules influence methanol structure and spectral properties under variable deposition temperatures. Additionally, this thesis develops a statistical analysis approach for the automatic extraction of detailed information from a single spectrum, offering retrospective analysis of the thermal history of solid water and methanol.
The laboratory work presented in this thesis includes five series of detailed, systematic experiments, utilising infrared (IR) and vacuum ultraviolet (VUV) spectroscopy. The experimental series (pure methanol ice, two types of water/methanol mixed ice, and two types of water/methanol layered systems) were designed to examine structural changes across deposition temperatures and investigate the interactions between water and methanol in different configurations. These included annealing experiments and isothermal observations of ice samples deposited at temperatures near their phase transition points. The experiments were carried out in the Portable Astrochemistry Chamber (PAC) under ultra-high vacuum (UHV) conditions across a controlled temperature range of 20–130 K, relevant to astrophysical environments. This novel, systematic approach focused on collecting large, detailed datasets, requiring the development of custom Python and macros scripts for data acquisition and analysis to handle these complex datasets. Beyond standard spectral analysis, the data were analysed using Principal Component Analysis (PCA) for further comparative assessment across multiple spectral datasets.
Key results from this work show that deposition temperature has a direct, spectroscopically visible, and reproducible effect on the crystalline structure of methanol that differ from traditional annealing experiments. Each experimental series demonstrated significant temperature-dependent changes in spectral profiles. This provided high-resolution insights into methanol’s phase transitions and isothermal ice evolution with 1 K precision. The analysis determined temperature points for structural changes observed in both isothermal evolution and annealing experiments. The experiments also identified characteristic spectroscopic features associated with phase transitions and interactions with water molecules, providing a deeper understanding of these effects. The annealing experiments offered further insights into the thermal evolution of the investigated samples. Moreover, implementing PCA modelling allowed for retrospective analysis of infrared spectral data, demonstrating the potential for tracking the environment and thermal evolution of solid methanol.
This work contributes to astrochemistry by refining our understanding of solid methanol structure, its thermal and isothermal evolution and interactions with water ice, under space-relevant conditions. It establishes a robust experimental and analytical framework for studying complex ice systems, including automated tools for handling large datasets. These contributions offer guidance for experimental design in astrochemical ice studies and support more accurate interpretation of astronomical observations. Furthermore, this study lays the groundwork for future investigations into the behaviour and properties of astrochemical ices under varied thermal and compositional regimes in astrophysical environments
Numerical Simulation of Sessile Droplet Dynamics in Evaporation
Get PDFMultiphase flow problems are omnipresent in numerous industrial processes and natural environments; in this realm, modulating the location and shape of evaporating sessile droplets on solid substrates is crucial in a range of applications where droplet dynamics matters, such as spray cooling processes, DNA analysis, display fabrication technologies, novel methods in water collection, cosmetics industry, fuel applications, and microfluidic systems. The motion of an evaporative liquid droplet on a substrate is relatively straightforward to conceptualise, but behind the scenes, the governing intrinsically complex physics is driven by macroscale microscale interplays.
Among the analytical, experimental and numerical techniques, regardless of the intrinsic merits of the first two approaches, they can be oversimplified, limited and expensive in dealing with empirical limitations and errors, respectively. Numerical methods are relatively straightforward to generalise and account for a broad range of complicated and hard-to-provide circumstances. Nevertheless, there are challenges in simulating precise fluid systems using computational fluid dynamics (CFD). Various interface tracking approaches have been introduced and developed to address the increasing complexity of multiphase flows in response to the growing demands of recent decades. The volume-of-fluid (VOF) method is one of the popular methods employed and included in Ansys FLUENT.
In this research, in order to numerically study microdroplet evaporation spreading over solid substrates as a liquid-vapour phase-changing system below the capillary length scale, a parametric study was performed to capture the microdroplet dynamics using the Georeconstruction method to accurately capture the droplet interface dynamics in parallel with the evaporation model of Lee on different substrate geometries, evaporation frequencies and wetting patterns. The hydrophobicity level (wetting pattern) and the phase change model parameters influence the evolution of the evaporating microdroplet.
Initially, for the Basis Spline (B-spline) hydrodynamically smooth solid surface with constant (ideal) contact angle (CA), as a homogenous substrate, droplet mass evolution, droplet-solid surface wetting area (DSSWA) change, droplet trajectory along with its speed using add-on C coding in FLUENT, and using image processing (IP) in Python, and droplet-solid surface interface perimeter (DSSIP) are investigated; additionally, developing the image processing code, the circularity index (CI) of DSSWA is calculated to monitor the circularity of the wetted area. The proposed CI technique can be used for droplet splitting detection and analysis as a quantitative method. The DSSWA can be used in applications that droplet wetting trace, and interface matters. Furthermore, droplet speed fluctuations are analysed using Fast Fourier Transform (FFT) and signal processing (SP) in MATLAB to investigate possible underlying statistical features. To facilitate the quantitative analysis of droplet rotation, some scripts have been written that calculate and monitor the droplet vorticity and helicity in a few cases. Using further case studies, this approach enables us to investigate the droplet phase dynamics and correlate them with other aforementioned factors.
Chapter by chapter, the complexity and realistic degree of the simulations escalates from an ideal wetting condition on a hydrodynamically smooth substrate (pining free substrate) in Chapter 5 followed by Chapter 6 including evaporation on the smooth substrates by two radial (continuous) gradient-based wetting patterns i.e., droplet holding and droplet repelling patterns, which are experimentally achievable using an active method of electric field and an array of electrodes through the concept of electrowetting-on-dielectrics introduction modifying the surface energy rendering CA variation or substrate laser etching as a passive wetting pattern manufacturing.
Chapter 6 includes non-ideal heterogeneous substrates, specifically with random patterns, either random wetting patterns with sharp contrast or contact angle hysteresis, or an ideal wetting pattern on rough substrates is considered.
The results for the ideal CAs (Chapter 5) show the dependency level of droplet dynamics on the wetting conditions as well as the evaporation frequency acting as a mass change intensity factor. The combined counterbalancing influences of the evaporation frequencies (directly) together with hydrophobicity level (inversely) on the droplet mass change are illustrated using three dimensional plot, which shows the partial outweighing effect of CA and have the potential to provide predicting correlations between droplet mass evolution, droplet evaporation frequency (EvpF) and CA; in other words, the highest EvpF and lowest CA amplifies the evaporation rate. Moreover, the concept of droplet residence time on a solid surface (DSSRT) is studied in all cases, which differs from droplet evaporation time (extinction).
The results of the gradient-based wetting (Chapter 6) show a high dependency level of droplet dynamics on the wetting pattern, and secondly, on the evaporation frequency. Additionally, the changes in DSSWA and DSSIP caused by the gradient wetting pattern are studied, which were opposite for the droplet-repelling and droplet-holding patterns. EvpF shows a peak value amplification and time-shifting feature in the CI and DSSWA plots. The droplet holding wetting pattern can significantly improve DSSRT, which is efficient for small substrates.
The results of Chapter 7 show that for a random wetting pattern with high CA contrast (60-120°), the DSSRT is higher than its constant CA counterparts, the liquid mass evolution is not linear, and its evaporation rate is higher than all the corresponding EvpF cases, even the hydrophilic case. For a flat substrate with a roughness level comparable to that of its smooth B-Spline counterpart under a fixed neutral wetting condition, the liquid mass evolution slope is higher, and the substrate roughness induces fluctuations.
The study of heterogeneous substrates reveals phenomena such as pinning, rapid evaporation induced instabilities, splitting, satellite droplet formation, and more intensive evaporation, leading to more complex dynamics.
Finally, some potential future works are enumerated in the last chapter
Polykrise als globales Phänomen? Perspektiven aus der Vergleichenden Politikwissenschaft Is polycrisis a global phenomenon? Perspectives from comparative politics
No full textIn recent years, the notion of “polycrisis” has become a key concept in debates about contemporary global transformations. It refers to the simultaneous occurrence and mutual reinforcement of multiple crises, including the COVID-19 pandemic, geopolitical conflicts, economic disruptions, and climate change. Yet to what extent is this constellation actually perceived worldwide as a coherent phenomenon? This debate article addresses this question from a comparative political science perspective by bringing together regional analyses of Africa, Latin America, East and Southeast Asia, Eastern Europe, the Middle East, and the Global North. The contributions examine, first, how crises are perceived and framed in the respective regions and whether the narrative of polycrisis is present at all. Second, they analyze how political systems and actors respond to multiple crises and what implications this has for democracy, authoritarianism, political stability, and international positioning. The comparative perspective reveals that the idea of a single global polycrisis only partially reflects empirical realities. While in the Global North the entanglement of multiple crises is often interpreted as an epochal rupture, many regions of the Global South emphasize experiences of structural vulnerability, long-standing crises, or external shocks. The concept of polycrisis thus appears less as a universal condition than as a contested interpretive framework whose relevance and consequences vary across regional contexts, institutional arrangements, and political narratives
Why continuity of carer matters in group care: A qualitative analysis of women's experiences of Pregnancy & Parenting Circles in England.
Get PDFBackground
Group Care, here described as Pregnancy and Parenting Circles (PPC), is a holistic model of maternity care characterised by a facilitative and interactive approach. Evidence indicates positive outcomes and experiences for women who participate. Its potential to enhance women’s empowerment, health and wellbeing as well as their relationships with healthcare services positions group care as an innovative model warranting further investigation.
Research Questions
This study examined: 1). the extent to which the PPC model adhered to the core values and components of Pregnancy Circles; 2). how fidelity to the model influenced women’s experiences of care; and 3) how established mechanisms of effect operated within PPC.
Methods
We draw on UK data from an implementation study, Group Care in the First 1000 Days (GC_1000). Data were generated through meeting notes, group session observations, semi-structured interviews and focus groups with service providers and users. A UK group care randomised controlled trial, REACH (trial registration no: ISRCTN91977441), provided a framework of core values and components utilised in an abductive analytical approach for examining model fidelity.
Results
Findings highlight ‘relational continuity’ as a central component of group care. Relational continuity functioned as a key lever, enabling mechanisms such as enhanced engagement and active participation in health. Lack of fidelity to continuity disrupted the model’s mechanisms, weakening its positive effects on women’s experiences of care.
Conclusion
Relational continuity is critical to operationalising the mechanisms underpinning group care. Attention to model fidelity is essential to optimise women’s experiences of group care
Human/AI Collective Intelligence for Deliberative Democracy: A Human-Centred Design Approach
Get PDFThis chapter introduces the concept of Collective Intelligence for Deliberative Democracy (CI4DD). We propose that the use of computational tools, specifically artificial intelligence to advance deliberative democracy, is an instantiation of a broader class of human-computer system designed to augment collective intelligence. Further, we argue for a fundamentally human-centred design approach to orchestrate how stakeholders can contribute meaningfully to shaping the artifacts and processes needed to create trustworthy DD processes. We first contextualise the key concepts of CI and the role of AI within it. We then detail our co-design methodology for identifying key challenges, refining user scenarios, and deriving technical implications. Two exemplar cases illustrate how user requirements from civic organisations were implemented with AI support and piloted in authentic contexts
Ethical Dilemmas in Educational Research: BERA Case Studies for Researchers by Researchers
No full textDrawing on the real voices and experiences of researchers, this book illustrates how the British Educational Research Association (BERA) Ethical Guidelines for Educational Research can be used to appraise research studies ethically. Researchers have choices when they design, conduct and report their research. These choices have consequences for others – funders, sponsors, those who facilitate access to research settings, those in the research settings, participants and the researchers. Sometimes the consequences can be anticipated and positive consequences can be maximised in the research design and negative consequences minimised. Sometimes the consequences only become apparent as the research unfolds.
This book presents a series of case studies following researchers in their decision-making through studies in a range of settings to consider different ways to deal with ethical dilemmas raised. The authors draw on their experiences to explain researcher thinking and how this relates to enacting values, pointing to relevant advice in the BERA ethical guidelines. They also explore choices not taken, considering the possible implications from such decisions, and how other researchers might have made different decisions based on different positionality. The book confronts rather than avoids the application of Global North derived guidance for research in settings other than the UK. As well as thought provoking case studies, the book puts forward questions for readers to relate to their own research contexts and recommended reading for further thinking about the issues raised
The positive value of media for children: replacing fear with fortitude
No full textThe term ‘media’ frequently has negative connotations; mass media, screen time and social media are all terms we may talk about in the primary school that feel heavily laden with fear and uncertainty. Research suggests that the public and educational debate often revels in portraying media as dangerous; Neuhaus and O’Connor (2025) found that media articles portraying screen time as universally ‘harmful’ spread significantly faster than balanced research, supporting the idea that this wave of worry fuels guilt and confusion for parents and carers, often leading to fear-based narratives in policy. With social media, the stories that hit the headlines are often the terrible tragedies that have occurred through connections made online. But in this article, the authors argue that alongside these awful events, are positive connections for many other children and young people
