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Bioprospecting for plant growth promoting microbes: Rich seams in long-term agricultural field experiments?
Get PDFInteractions between plants and microbes are believed to have facilitated the conquest
of land and to this day profoundly affect the success of plants. Naturally occurring soil
microbes – especially the subset that live associatively with plant roots – offer the
potential to contribute to the sustainable intensification of agriculture by a variety of
means, including the suppression of plant diseases and provision of nutrients.
However, the effects of different agricultural management practices and cropping
systems on the proliferation of beneficial microbes may determine the manifestation
of these functions. The design of the Broadbalk winter wheat experiment at
Rothamsted has ensured that a diverse range of biotic and abiotic selective pressures
associated with different combinations of such treatments have acted continuously on
resident soil microbes over the last 180 years, both directly and mediated via
continuously cultivated crop plants. This thesis presents an investigation into the utility
of this living experiment to advance our understanding of the plant microbiome under
various environmental stressors principally surrounding nutrient limitations. The
central role of inorganic nitrogen amendments in structuring the rhizosphere
microbiome at Broadbalk was revealed by a bacterial 16S rRNA gene amplicon
sequencing survey in tandem with robust soil chemical analyses. A high-throughput,
culture collection pipeline was developed to integrate functional characterisations of
resultant rhizosphere microbial communities by screening isolate libraries in vitro. The
role of mineral nitrogen inputs dominated outcomes, and no enrichment of putatively
plant growth promoting (PGP) microbial traits relevant to nutrient limitations in the plots
from which they were cultured were exhibited, potentially a result of thorough
geochemical depletions through repeated cropping. This multifaceted approach
towards understanding the nature of selection for PGP microbial associations holds
significant promise and the data and biological resources generated can be further
leveraged to develop microbial solutions to problems faced by contemporary
agricultural systems
An investigation of gene-diet interactions on lipid-related traits in different ethnic groups
Get PDFCardiometabolic diseases including cardiovascular diseases (CVDs) remain a threat
to global public health, placing a significant burden on low- and middle-income countries.
Among the risk factors for CVDs is an altered blood lipid profile, usually characterised by a
rise in the concentration of triglycerides (TG) or low-density lipoprotein cholesterol (LDL-C) and a reduction in the concentration of high-density lipoprotein cholesterol (HDL-C).
Lipid-related traits such as CVDs are known to be impacted by environmental factors
including dietary intake. However, evidence from genetic association studies indicates that
genetic variants play a role in the development of these traits. Therefore, investigating how
gene-diet interactions impact on lipid-related traits could help to improve our
understanding of the underlying pathophysiology and the development of precision
nutrition strategies for the prevention and management of these conditions. Gene-diet
interaction studies have been extended to cover previously under-represented populations,
but there is still limited research in some developing countries. The main aim of this PhD
work was to investigate the association of single nucleotide polymorphisms (SNPs) as a
genetic risk score (GRS) with lipid-related traits in different ethnic groups. The interaction
of the GRS with dietary factors on lipid-related traits was also assessed. Additionally, the
association between dairy intake, a source of saturated fat, on cardiometabolic risk factors
was investigated. Finally, factors that need to be considered to facilitate the translation of
nutrigenetics to personalised and precision nutrition for cardiometabolic health in diverse
ethnic groups were explored. This thesis included seven studies: a review of cholesteryl
ester transfer protein (CETP) gene-diet interactions on lipid-related outcomes; three cross-sectional cohort studies [the Obesity, Lifestyle and Diabetes in Brazil (BOLD) study, Brazilian
young adults, n=190; the Chennai Urban Rural Epidemiological Study (CURES), Asian Indian
adults, n=1,033; and the Study of Obesity, Nutrition, Genes and Social factors (SONGS),
Peruvian young adults, n=468]; a case-control study (CURES, Asian Indian adults, n=497); a
systematic review of gene-lifestyle interactions on cardiometabolic disease-related traits in
Latin American and Caribbean populations; and a review focusing on the barriers in
translating existing nutrigenetics insights to precision nutrition for cardiometabolic health
in ethnically diverse populations. Statistical analyses were performed using the Statistical
Package for the Social Sciences (SPSS) software (version 28; SPSS Inc., Chicago, IL, USA) and
the R software version 4.3.1. Significant GRS-saturated fatty acid (SFA) intake interactions
were observed in the Brazilian and Asian Indian populations, impacting on TG:HDL-C ratio
(Pinteraction=0.03) and waist circumference (Pinteraction=0.006), respectively. A significant GRS-
total fat intake interaction on TG:HDL-C ratio was also observed in the Brazilian population
(Pinteraction=0.03). In the Peruvian population, a significant GRS-carbohydrate intake
interaction on the concentration of HDL-C was observed (Pinteraction=0.0007). Also in the
Peruvian population, participants with a high GRS, had lower concentrations of HDL-C across
tertiles of glycaemic load (Ptrend=0.017). In summary, the findings of this thesis add to the
field of nutrigenetics by showing the presence of genetic heterogeneity in gene-diet
interactions on lipid-related traits in different ethnic groups. These findings will contribute
to improved understanding of how genetic and dietary factors interact to alter the
susceptibility to CVDs in different ethnic groups. Replication of the findings in large scale
longitudinal and dietary intervention studies is required prior to being considered for
personalised dietary guidelines
A systematic review and meta-analysis of physical environmental enrichment to improve animal welfare-related outcomes in indoor cattle
Get PDFThis systematic review aims to evaluate the effectiveness of various physical environmental enrichment items such as brushes, ropes, teats, chains, balls, cowhides/blocks, at improving the welfare of indoor-housed calves, heifers, and cattle. This review of 33 peer-reviewed papers and one industry report evaluated different welfare-related outcomes following physical environmental enrichment, including feed intake, lying time, play and exploratory behaviour, aggression, stereotypic behaviour and cross-sucking behaviour. The results of the meta-analysis revealed that calves and heifers enrolled in experimental studies using enrichment items had significantly improved growth rates, and increased locomotor play, but the overall reduction in cross-sucking behaviour was small and non-significant. The effect of enrichment on feed intake, aggression/stereotypic behaviour, play behaviour, cleanliness score contrasted between studies, with some reporting improvements while others showed no effect of environmental enrichment in these parameters. The risk of bias assessment revealed limitations in researcher blinding, sequence generation, and allocation concealment across the literature assessing the effectiveness of environmental enrichment on animal welfare. Overall, this review underscores the significant positive impact of physical enrichment on the welfare and behaviour of indoor-housed cattle, while highlighting the need for further research to optimise enrichment strategies across different cattle age groups and housing conditions
Age at arrival and immigrants’ housing outcomes: evidence from the UK
Get PDFWe provide new evidence on how immigrants’ age at arrival relates to their housing tenure and living conditions in the UK. While previous research has examined the role of socio-economic and demographic factors in immigrants’ housing outcomes, the effect of age at migration remains underexplored. Using a representative dataset from the UK Household Longitudinal Study, we analyse how immigrants’ arrival age is associated with their likelihood of homeownership, reliance on social housing, and housing quality. Our findings confirm that those who arrive as adults face significantly lower homeownership prospects than those who arrive aged 0–5 years, with the oldest arrivals exhibiting a 44-percentage-point gap. Contrary to expectations, later arrivals are not more likely to rely on social housing than earlier arrivals or natives. Furthermore, we find no strong evidence that housing or neighbourhood quality differs systematically based on age at arrival. These results provide insight into the link between immigrant generations, housing market segments and housing quality outcomes with implications for household welfare. The findings are therefore relevant for policymakers and valuable for local and regional expenditure, forecasting, and economic development
Setting the stage: line managers' HR orientation as an antecedent to perceived HR effectiveness
Get PDFThe field of strategic human resource (HR) management has shown an increasing focus on how employees perceive and react to their organization's HR practices. In this perspective, employees are not passive recipients of HR policies or mere observers of their managers' HR implementation strategies. Rather, their perceptions play a critical role in shaping organizational culture and fostering high‐performing workplaces. However, important questions remain regarding how line management roles shape not only employees' assessments of their work environment but also their perceptions of HR effectiveness. Drawing on cognitive appraisal theory, we argue that line managers' compliance‐ versus commitment‐focused orientations influence employee appraisals of threats and challenges in their jobs. These appraisals, in turn, shape how employees evaluate the effectiveness of their organization's HR practices (i.e., perceived HR effectiveness). Using qualitative data from focus groups and a multilevel quantitative research design, we find evidence supporting our hypotheses, showing that line managers' HR orientations significantly influence employees' cognitive appraisals and subsequent perceptions of HR effectiveness. We conclude by discussing the theoretical contributions and offering practical recommendations for improving the implementation of HR practices
4D printed polymethacrylate lattices capable of dimensional switching and payload release via photoresponsive actuation of azobenzene units
Get PDFIn this report, we demonstrate the synthesis of photoresponsive polymeric hydrogel lattices using stereolithographic 3D printing to afford objects that can change shape when irradiated with UV-vis light. Methacrylate-based monomers featuring azobenzene units were used as the photo-actuator components. Co-polymerisation of these monomers with 2-hydroxyethyl methacrylate produced well-defined hydrogel lattices. Photo-actuation of the hydrogels led to contraction of the 3D printed lattices up to 23 % by volume. The ability of such photoresponsive hydrogel lattices to exhibit payload release has been studied using methylene blue as a drug mimic. Upon irradiation, the hydrogel lattice was squeezed like a sponge through photo-induced actuation in pulses, resulting in the controlled release of the pro-drug over 24 hours
Application of indoor greenhouses in the production of thermal energy in circular buildings
Get PDFThe production of thermal energy in buildings using internal greenhouses makes it possible to obtain substantial gains in energy consumption and, at the same time, contribute to improving occupants’ thermal comfort (TC) levels. This article proposes a study on the producing and transporting of renewable thermal energy in a circular auditorium equipped with an enveloping semi-circular greenhouse. The numerical study is based on software that simulates the building geometry and the building thermal response (BTR) numerical model and assesses the TC level and indoor air quality (IAQ) provided to occupants in spaces ventilated by the proposed system. The building considered in this study is a circular auditorium constructed from three semi-circular auditoriums supplied with internal semi-circular greenhouses. Each of the semi-circular auditoriums faces south, northeast, and northwest, respectively. The semi-circular auditoriums are occupied by 80 people each: the one facing south throughout the day, while the one facing northeast is only occupied in the morning, and the one facing northwest is only occupied in the afternoon. The south-facing semi-circular greenhouse is used by itself to heat all three semi-circular auditoriums. The other two semi-circular greenhouses are only used to heat the interior space of the greenhouse. It was considered that the building is located in a Mediterranean-type climate and subject to the typical characteristics of clear winter days. The results allow us to verify that the proposed heating system, in which the heat provided to the occupied spaces is generated only in the semi-circular greenhouse facing south, can guarantee acceptable TC conditions for the occupants throughout the occupancy cycle
Discourse planning and production in post-stroke aphasia: the role of executive function on pauses and clauses
No full textBackground
Despite agreement that both discourse production and executive functions are impaired in people with aphasia, very little is known regarding real-time time planning and production of discourse in aphasia or the potential role of executive function abilities. Temporal speech measures, such as duration of pausing and pause location within the discourse structure, also remain poorly understood. Thus, studying pause behaviors in the context of their relationship with measures of executive functioning stands to inform us about the real-time planning and production of discourse.
Aim
To investigate the relationship between executive functions and discourse production in people with aphasia, using pauses as a reflection of real-time clause planning and clause type and length as measures of offline clause planning.
Methods & Procedures
People with aphasia (n = 16) produced spoken Cinderella stories and completed several executive function tasks. The stories were coded for clause type (e.g. independent, dependent) and number of words per clause. Using speech analysis software, discourse samples were also coded with respect to the location (between-, within- clauses), number, and duration of pauses. A composite pause behavior measure was derived from duration and number of silent and filled pauses. Similarly, a composite executive function measure was derived from the following tests: Verbal fluency, trail making, Stroop, and digit span. Mixed effects models were used to examine the effect of executive functioning ability on pause behavior, their location, clause type, and clause length (number of words).
Outcomes & Results
Executive functions were related to pause location such that participants with relatively better executive function (relative to other participants in the sample) produced more pauses between than within clauses; in contrast, the participants with relatively poorer executive function produced more pauses within than between clauses. Participants with better executive function produced more pauses in independent than minor (i.e. erroneous) clauses, while those with poorer executive function produced more pauses in minor than independent clauses. Regarding diversity of clause types, persons with poorer executive function produced more minor clauses than those with better executive function. Executive function ability did not influence number of words in the clause.
Conclusions
Individuals with relatively higher and lower performance on executive function tasks produced different types of clauses and showed different patterns of pause behavior as a function of clause type