An Ultrastructural and Histological Study of the Equine Respiratory Tract in Health and Disease, Volume I

There were two main aims in the work presented in this thesis. First, to carry out a detailed scanning electron microscopic (SEM), histological and, where appropriate, transmission electron microscopic (TEM) study of the surface features of the entire respiratory tract of normal horses. The second aim was to investigate the effects of respiratory disease (Streptococcus equi infection or Strangles and chronic obstructive pulmonary disease) on equine respiratory tract surfaces

Where have all the heathers gone?

Heathers have been cultivated for several centuries, both the hardy heaths (Calluna, Daboecia and Erica) from the northern hemisphere and the more frost-tender species of Erica from southern Africa known as Cape heaths. In the late 19th century, a number of heather gardens were created, especially in Britain, and the popularity of heathers as long-lasting garden plants reached its zenith in western Europe and temperate North America in the late 20th century. At about the same time, deliberate breeding and selecting of Calluna vulgaris (ling) for flowers that lack normal sexual parts and remain bud-like led to a revolution in heather production with tens of millions of these bud-bloomer Calluna propagated each year for an ephemeral trade dominated by throwaway plants. Concomitantly, the diversity of hardy heathers offered by the trade has declined sharply with a small number of artificially raised clones, protected by plant breeders’ rights, now dominating the market. In contrast, the discovery of living lineages of a few Erica species that are extinct in the wild in South Africa has led to successful reintroduction programmes, particularly of Erica verticillata. The Erica Conservation Consortium, inaugurated in 2020, aims to coordinate and prioritise ex situ conservation of endangered Cape heaths.publishedVersio

A Brief Record of the Advance of the Egyptian Expeditionary Force under the Command of General Sir Edmund H. H. Allenby, G. C. B., G. C. M. G.

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Meta-analysis suggests differing indirect effects of viral, bacterial, and fungal plant pathogens on the natural enemies of insect herbivores

Indirect effects are ubiquitous in nature, and have received much attention in terrestrial plant–insect herbivore–enemy systems. In such tritrophic systems, changes in plant quality can have consequential effects on the behavior and abundance of insect predators and parasitoids. Plant quality as perceived by insect herbivores may vary for a range of reasons, including because of infection by plant pathogens. However, plant diseases vary in their origin (viral, bacterial or fungal) and as a result may have differing effects on plant physiology. To investigate if the main groups of plant pathogens differ in their indirect effects on higher trophic levels, we performed a meta-analysis using 216 measured responses from 29 primary studies. There was no overall effect of plant pathogens on natural enemy traits as differences between pathogen types masked their effects. Infection by fungal plant pathogens showed indirect negative effects on the performance and preference of natural enemies via both chewing and piercing-sucking insect herbivore feeding guilds. Infection by bacterial plant pathogens had a positive effect on the natural enemies (parasitoids) of chewing herbivores. Infection by viral plant pathogens showed no clear effect, although parasitoid preference may be positively affected by their presence. It is important to note that given the limited volume of studies to date on such systems, this work should be considered exploratory. Plant pathogens are very common in nature, and tritrophic systems provide an elegant means to examine the consequences of indirect interactions in ecology. We suggest that further studies examining how plant pathogens affect higher trophic levels would be of considerable value

Consistency between ARPES and STM measurements on SmB6_6

Strongly correlated topological surface states are promising platforms for next-generation quantum applications, but they remain elusive in real materials. The correlated Kondo insulator SmB$_6$ is one of the most promising candidates, with theoretically predicted heavy Dirac surface states supported by transport and scanning tunneling microscopy (STM) experiments. However, a puzzling discrepancy appears between STM and angle-resolved photoemission (ARPES) experiments on SmB$_6$. Although ARPES detects spin-textured surface states, their velocity is an order of magnitude higher than expected, while the Dirac point -- the hallmark of any topological system -- can only be inferred deep within the bulk valence band. A significant challenge is that SmB$_6$ lacks a natural cleavage plane, resulting in ordered surface domains limited to 10s of nanometers. Here we use STM to show that surface band bending can shift energy features by 10s of meV between domains. Starting from our STM spectra, we simulate the full spectral function as an average over multiple domains with different surface potentials. Our simulation shows excellent agreement with ARPES data, and thus resolves the apparent discrepancy between large-area measurements that average over multiple band-shifted domains and atomically-resolved measurements within a single domain

Population, sexual and reproductive health, rights and sustainable development: forging a common agenda.

This article suggests that sexual and reproductive health and rights activists seeking to influence the post-2015 international development paradigm must work with sustainable development advocates concerned with a range of issues, including climate change, environmental issues, and food and water security, and that a way of building bridges with these communities is to demonstrate how sexual and reproductive health and rights are relevant for these issues. An understanding of population dynamics, including urbanization and migration, as well as population growth, can help to clarify these links. This article therefore suggests that whether or not sexual and reproductive health and rights activists can overcome resistance to discussing "population", become more knowledgeable about other sustainable development issues, and work with others in those fields to advance the global sustainable development agenda are crucial questions for the coming months. The article also contends that it is possible to care about population dynamics (including ageing and problems faced by countries with a high proportion of young people) and care about human rights at the same time. It expresses concern that, if sexual and reproductive health and rights advocates do not participate in the population dynamics discourse, the field will be left free for those for whom respecting and protecting rights may be less of a priority

Decarbonising the Swedish road transport sector

Road transport contributes to around one-fifth of the EU’s total CO2 emissions and is the only major sector in the EU where greenhouse gas emissions are still rising. Swedish road transport causes 30% of all emissions. Addressing transport emissions is therefore crucial for meeting the Paris Agreement commitments on climate change. The Swedish government aims to have a fossil-independent vehicle fleet by 2050; moreover, an emissions reduction target for the road transport sector of 80% (compared to 2010) by 2030 has been suggested. The government-initiated investigation ‘Fossilfrihet på väg’ sets out potential pathways, but a knowledge gap currently remains in regard to which path would be the most beneficial or least burdensome in terms of macroeconomic effects while still decarbonising the road transport sector. This paper contributes to fill that knowledge gap by applying a vehicle stock modelling framework and a demand-driven global econometric model (E3ME) and by evaluating different technology pathways for Sweden to meet the 2030 and 2050 government targets. The stock model has been adjusted to be consistent with ‘Fossilfrihet på väg’ and uses technology deployment and cost estimates to model the Swedish vehicle stock emissions in three technology-driven scenarios. The analysis shows that decarbonisation of transport can have positive impacts upon the Swedish economy, primarily through the replacement of imported fossil fuels with domestically produced electricity and biomass, while a further stimulus is provided by the construction of infrastructure to support electric vehicle recharging and fuel cell refuelling. Through quick action to encourage the deployment of new technologies and powertrains into the vehicle stock, plus policies aimed at promoting the domestic production of sustainable biomass, Sweden can maximise the potential gains from the decarbonisation process