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Root morphological adaptation and leaf lipid remobilization drive differences in phosphorus use efficiency in rapeseed seedlings
Get PDFWith the objective of investigating the basis of phosphorus (P) utilization efficiency (PUE), physiological and morphological traits, two P-efficient and two P-inefficient rapeseed (Brassica napus L.) cultivars were compared at the seedling stage. P-efficient cultivars showed root morphological adaptation, high P uptake activity, and greater phospholipid degradation under low P stress. Improving root morphological adaptation and reducing lipid-P allocation could allow increasing PUE in rapeseed seedlings
Essays on causal analysis in cointegrated systems: causality, exogeneity, and driving forces
Get PDFThe appropriate definition, role and use of exogeneity in economic analysis has been an area of considerable contention. The empirical resolution of these disputes has proven to be challenging due to the incongruity between the econometric tools, which rely on statistical considerations, and the theoretical perspectives that emphasize causal relationships. The findings of this thesis aim to reconcile these two perspectives by investigating whether causal features manifest in model coefficients.
Drawing on the properties of the graphical representation of the latent causal structure, the first chapter introduces a causal definition of exogeneity. Exploiting state-of-the-art tools in the field of cointegration analysis, we investigate the interplay between causal exogeneity and the restrictions it imposes on models, without requiring that all relevant variables are observed. The duality between causal exogeneity and the restrictions on model parameters lays the foundation for the development of testing procedures tailored to facilitate causal logic.
The second chapter identifies an additional duality between model restrictions and causal properties and leverages it to propose an alternative testing technique. The chapter also evaluates the performance of the two tests using simulated data and demonstrates their practical utility through an empirical illustration on monetary variables.
The third chapter examines the causal interpretation of weak exogeneity and cautions against associating it with causality. The chapter's findings are particularly pertinent in the context of cointegrated systems, where weak exogeneity is associated with constraints on the adjustment matrix. This coupling has led to misinterpretations, since variables unaffected by steady-state violations are associated with non-causality, and the absence of weak exogeneity is incorrectly perceived as a characteristic of causally affected variables. We aim to demonstrate that this duality is not automatic and clarify under what circumstances weak exogeneity can or cannot serve as a proxy for causal inference
Evidence of heating-dominated urban NOx emissions
Get PDFRoad transport NOx emissions in many high-income countries have steadily reduced due to improved exhaust after-treatment technology. However, ambient concentrations of NO2, O3 and PM2.5 continue to exceed World Health Organization guidelines in many cities globally. The megacity of London has taken an international lead in mobility interventions through the use of low-emission zones. Using long-term air pollution flux measurements made from a communications tower, we show that the largest source of NOx emissions in central London has transitioned from road transport to space heating. Observations and supporting consumption/mobility data indicated that natural gas combustion in boilers was responsible for 72 ± 17% of NOx emissions in the measurement footprint (average years 2021–2023). Road transport has dominated air quality thinking on NO2 for many decades. However, in urban environments that are reliant on natural gas, building heating may now be an effective sector to prioritize for further NOx emissions intervention. With system-wide changes in the heat and power sector expected in the coming decades to achieve decarbonisation pledges, we project that very low urban emissions of NOx are achievable. The trajectory will, however, depend on choices made around urban buildings and their associated infrastructure and whether low-carbon fuel combustion or electrification pathways are chosen. We estimate a damage cost penalty of up to £600 M in the U.K. should hydrogen combustion replace natural gas for heating rather than technologies such as heat pumps
Reflecting on the science of climate tipping points to inform and assist policy making and address the risks they pose to society
Get PDFThere is a diverging perception of climate tipping points, abrupt changes and surprises in the scientific 10 community and the public. While such dynamics has been observed in the past, e.g., frequent reductions of the Atlantic meridional overturning circulation during the last ice age, or ice sheet collapses, tipping points might also be a possibility in an anthropogenically perturbed climate. In this context, high impact-low likelihood events, both in the physical realm as well as in ecosystems, will be potentially dangerous. Here we argue that a formalized assessment of the state of science is needed in order to establish a 15 consensus in this issue and to reconcile diverging views. This has been the approach taken by the Intergovernmental Panel on Climate Change (IPCC). Since 1990, the IPCC has consistently generated robust consensus on several complex issues, ranging from the detection and attribution of climate change, the global carbon budget and climate sensitivity, to the projection of extreme events and their impact. Here, we suggest that a scientific assessment on tipping points, conducted collaboratively by the 20 IPCC and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), would represent an ambitious yet necessary goal to be accomplished within the next decade
Anaerobic digestion of whey permeate: impact of feedstock ratio and organic loading rate in batch and semi-continuous systems
No full textThere is strong evidence that why permeate anaerobic digestion plants face significant challenges in maintaining a stable operation for long time and this study aimed to optimize this process.We investigated the anaerobic digestion (AD) performance of whey permeate under batch and semi-continuous stirred tank reactor (s-CSTR) systems. Biochemical methane potential (BMP) tests were initially performed in batch reactors to assess whey permeate potential as AD substrate operating at different inoculum to substrate ratios (ISRs) and pH values under mesophilic temperatures. The kinetic parameters from the best AD performance under batch system were also assessed to be used as the guideline for s-CSTR operational set ups. The highest methane yield of 653.64 12.16 NLCH4kgVS-1 was observed at ISR 2, initial pH 7.5 at 37C incubation under batch system. However, when the kinetic parameters from this condition were applied to determine the organic loading rate (OLR) and hydraulic retention times (HRT) in the s-CSTRs, resulted in operational failure. The s-CSTRs were then operated at OLR 2.5 and 4 gVSL-1d-1 with 30 d HRT for 150 d to assess the effect of different feeding regimes towards the overall AD performance. The CH4 production rate declined for 3 HRTs in all reactors before stabilizing for the rest of the experiment. The decline of CH4 rate was observed to be correlated with volatile solids degradation, volatile fatty acids and microbial composition. Initially, acetogenic bacteria (e.g., Trichococcus and Sedimentibacter) dominated the digestate which shifted to propionic acid producing bacteria (e.g., Actinomyces and Acidipropionibacterium) over the course of 150 d. A change in archaeal abundance was also observed where abundant Methanosarcina declined and finally substituted by Methanobacterium. The change in microbial population of whey permeate AD under s-CSTR system in our study, suggests a shift in methanogenesis pathway, which directly affects the AD performance
The role of self-reflective practice of autistic students on their behaviour in the classroom
Get PDFRecent data shows an increasing number of exclusions and suspensions of autistic
students from mainstream schools with the key issue highlighted as persistent disruptive
behaviour. The aim of this study is to support autistic students, who are at risk of
exclusion or suspension or exhibit high levels disruptive behaviour, develop self-reflective skills, become more self-aware of their behaviour and manage it in the
classroom. This study will fill a gap in research, where there is rarity of studies exploring
the self-reflections of autistic students. This is due to key research purporting to autistic
individuals’ lack of the perception of others, known as ‘Theory of Mind’ (Baron-Cohen,
1990, 1991, 2000; Decety, 2010; Rameson et al., 2012), and awareness of self (Attwood,
2006; Volkmar 2011). However, research also indicates the capacity for the development
of theory of mind and reflection like Kliman, (2011, 2018) whose research was based on
‘Reflective Network Theory’ and Brosnan (2017, 2017) who suggested that decision
making based on Process 2 is reflective contemplative cognition, logical and deliberate,
citing that autistic individuals have greater logical reasoning (Brosnan, 2016, 2017). The
current study used a qualitative approach to address the phenomenon of behaviour,
employing a comprehensive reflective checklist as outlined by Plack et al., (2005) to
identify the types of reflections. Five autistic participants from a mainstream school
contributed their lived experiences over one school term, through training sessions and
the aid of reflective logs. The key themes emerging using Interpretative
Phenomenological Analysis as outlined by Smith et al, (2021), revealed participants’ both
acknowledgement and reflection of their disruptive behaviour, awareness of the impact
of friendship and interactions with teachers on their behaviour, reflect on the impact of
their behaviour on others, as well as the impact and importance of the training sessions
on their behaviour. However, students self-managing fully disruptive behaviour, which
can lead to exclusion or suspension, was not fully realised in the timeframe of the study.
Though the findings cannot be generalised from such small sample, the significance of
the findings suggests that self-awareness of behaviour through self-reflective practice can
be taught although it requires time to develop. The study offers an effective first step to
adapt behaviour management practices around support for autistic students’ self-awareness skills. A key recommendation is to introduce a whole-school adaptation to the current methods and practices associated with the delivery of the Zones of Regulation
(Kuypers, 2011, 2013, 2023) to better assist autistic students in behaviour management
Strategic HRM and generative AI: case studies on successful implementation of Gen AI in SHRM
No full textSitcom’s sonic sisterhoods: pop and punk as playful challenge in Girls5Eva and We Are Lady Parts
Get PDFThis article explores how music performance is presented as a space of freedom and collective creativity in two comedies centred on female musicians. The punk band of We Are Lady Parts and the pop girl group of Girls5eva are part of television’s intermittent engagement with stories of musicians, and employ the elastic realities offered by the musical genre. Both comedies offer satirical jabs and sceptical gazes at social norms of womanhood. We Are Lady Parts positions its Muslim female punk band within a cultural legacy of riot grrrl and punk as do-it-yourself spaces of female fury and communities for challenging gendered social constructs. The programme offers a comic play with the gendered norms of British Muslim identity and the band’s struggle to maintain their punk ideals. Girls5eva is part of a recent cultural reckoning with 1990s and 2000s white post-feminist pop culture, and follows the indignities experienced by a failed manufactured girl group who attempt to reunite in middle age. It presents a satirical reconsideration of their youth spent in an exploitative pop machine and renders the mundane everyday of mid-life womanhood through the comic absurd. Both programmes use music as an expressive device to explore those who sit outside of television’s dominant comic model of ‘imperfect’ womanhood, the white middle-class messy millennial. In centring Muslim and mid-life women, respectively, We Are Lady Parts and Girls5eva offer performance and collective creativity as a space for their comic quartets to play with and push against social and cultural expectations of womanhood in a range of forms
