Seasonal facilitative and competitive trade‐offs between shrub seedlings and coastal grasses

Shrub expansion is occurring in grasslands globally and may be impacted by the balance of competition and facilitation with existing grasses. Along the mid‐Atlantic and Gulf coasts, the native shrub Morella cerifera (wax myrtle) is rapidly expanding and displacing other native coastal species. Recent research suggests that much of this expansion is due to warming winter temperatures, as temperatures below −15°C kill M. cerifera. The objective of this project was to understand the importance of species interactions with grasses on the growth and physiology of M. cerifera at the seedling life stage through both field and laboratory experiments. In the field, grasses were removed around seedlings and microclimate and shrub physiology and growth were measured. Seeds and seedlings were experimentally frozen to measure the freeze tolerance at both life stages. We found that grasses provided ~1.3°C insulation to shrubs during winter. A freezing threshold for M. cerifera seedlings was experimentally found between −6°C and −11°C, but seeds remained viable after being frozen to the coldest ecologically relevant temperatures. Seedlings competed for light with grasses during warm months and grew more where grasses were clipped, revealing a trade‐off between winter insulation and summer light competition. Morella cerifera exhibits ecosystem engineering at the seedling stage by significantly reducing summer maximum temperatures. When seedlings are very young (less than one year), grasses appear to improve germination and seedling survival. These phenomena enable rapid expansion of M. cerifera across the landscape and likely inform shrub expansion mechanisms in other systems. Although seedlings are small and relatively vulnerable, this life stage appears to have significant implications for ecosystem trajectory in grasslands undergoing shrub encroachment

Jeremiah 48 as Christian Scripture

The oracle concerning Moab in Jeremiah 48 is one of the 'hard texts' of the OT. This thesis seeks to find a means of reading the oracle in a way that does justice to the text both in its ancient context and in a Christian frame of reference. The opening chapter reviews existing scholarship on this text (and related texts). The two chapters which then follow preface and contextualise the main discussion; they focus, respectively, on the differing textual traditions in MT and LXX, and on the parallel material in Jeremiah 48 and Isaiah 15-16. It transpires that MT Jeremiah 48 contains a more marked note of lament than LXX Jeremiah 31 and that Jeremiah 48 has a broader purview than Isaiah 15-16. Chapters Four and Five then examine how US and UK Christian interpreters have dealt with the text; those from the US are Fretheim, Miller and Brueggemann, while those from the UK are Jones and Clements. The US scholars in particular bring out some key elements of the oracle: the tone of lament (Fretheim), God's sovereignty (Miller), and Moab's pride and plays for power (Brueggemann).The last two chapters offer a fresh reading. Chapter Six proposes that the problematic 48:10 was inserted by a scribe who longed to see the words of Jeremiah 48 brought to completion. Chapter Seven considers Jeremiah 48 as a whole, noting rhetorical features that suggest Moab’s history has a cyclical nature in which Moab's sin leads to her destruction, but then she is restored again. Finally, two film-like imaginative readings explore the possible continuities and differences between Jeremiah 48 in its ancient context and in a Christian frame of referenc

Dysregulation in myelination mediated by persistent neuroinflammation: Possible mechanisms in chemotherapy-related cognitive impairment

AbstractCognitive impairment is commonly reported as a consequence of chemotherapy and can have considerable impact on everyday life on cancer patients. Thus, it is imperative to have a clear understanding of this phenomenon and the underlying mechanism involved. In the present study we examined the role of neuroinflammation and myelination in chemotherapy-related cognitive impairment. Female Sprague–Dawley rats (12-months old) were used in the study (total n=52, 13rats/group). Rats were randomly assigned to either the chemotherapy or saline control group. The drug combination of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) was given i.p. once a week for 4weeks. Rats in the control group received normal saline of equal volume. Animals from each group were further randomized to receive either: cyclooxygenase (COX-2) inhibitor, NS-393, to block the inflammatory response or vehicle. NS-398 was given at 10mg/kg i.p. and equal volume of saline (vehicle) was injected i.p. as vehicle. Both NS-398 and vehicle were injected 1h after the first CMF dose and then given daily for 28days then rats were tested in the Y maze. Our data showed that: (1) CMF led to the increase in the levels of inflammatory mediators IL-1β, TNF-α, and COX-2 while levels of the anti-inflammatory cytokine IL-10 decreased; (2) cognitive impairment and neuroinflammation resulting from CMF persisted 4weeks after the treatment ended; and (3) administration of NS-398 attenuated CMF-induced neuroinflammation and effects on myelin and cognitive impairment. These findings suggest the involvement of neuroinflammation in CMF-induced changes in myelin and myelination, and cognitive impairment

Cytochrome P450 CYP1B1 interacts with 8-<i>methoxypsoralen</i> (8-MOP) and influences psoralen-Ultraviolet A (PUVA) sensitivity

Background: There are unpredictable inter-individual differences in sensitivity to psoralen-UVA (PUVA) photochemotherapy, used to treat skin diseases including psoriasis. Psoralens are metabolised by cytochrome P450 enzymes (P450), and we hypothesised that variability in cutaneous P450 expression may influence PUVA sensitivity. We previously showed that P450 CYP1B1 was abundantly expressed in human skin and regulated by PUVA, and described marked inter-individual differences in cutaneous CYP1B1 expression.Objectives: We investigated whether CYP1B1 made a significant contribution to 8-methoxypsoralen (8-MOP) metabolism, and whether individuality in CYP1B1 activity influenced PUVA sensitivity.Methods: We used E. coli membranes co-expressing various P450s and cytochrome P450 reductase (CPR) to study 8-MOP metabolism and cytotoxicity assays in CYP1B1-expressing mammalian cells to assess PUVA sensitivity.Results: We showed that P450s CYP1A1, CYP1A2, CYP1B1, CYP2A6 and CYP2E1 influence 8-MOP metabolism. As CYP1B1 is the most abundant P450 in human skin, we further demonstrated that: (i) CYP1B1 interacts with 8-MOP (ii) metabolism of the CYP1B1 substrates 7-ethoxyresorufin and 17-b-estradiol showed concentration-dependent inhibition by 8-MOP and (iii) inhibition of 7-ethoxyresorufin metabolism by 8-MOP was influenced by CYP1B1 genotype. The influence of CYP1B1 on PUVA cytotoxicity was further investigated in a Chinese hamster ovary cell line, stably expressing CYP1B1 and CPR, which was more sensitive to PUVA than control cells, suggesting that CYP1B1 metabolises 8-MOP to a more phototoxicmetabolite(s).Conclusion: Our data therefore suggest that CYP1B1 significantly contributes to cutaneous 8-MOP metabolism, and that individuality in CYP1B1 expression may influence PUVA sensitivity

Integrating environmental sustainability considerations into food and nutrition policies : insights from Australia\u27s national food plan

The environmental sustainability (ES) of food systems is a critical challenge for policy makers. This is a highly contested policy area with differing views among stakeholders. The aim of the study was to develop a better understanding of how ES considerations are addressed in Australian food and nutrition policies and the way that consultation processes affect final policy outcomes. A mixed-methods study design combined a detailed chronology of key policy developments (2009-2015), a content analysis of written submissions obtained during the NFP\u27s consultation period (2011-2013) and a frame analysis of the sustainability perspectives - efficiency, demand restraint, and system transformation - in the NFP\u27s Issues, Green, and White Papers. There were 555 written submissions responding to two consultation papers. Stakeholders represented all sectors of Australia\u27s food system including government, non-government organizations, the food supply chain, research and academic institutions, and members of the general public. Around 74% of submissions referred to ES considerations and ~65% supported their inclusion into the final policy. Efficiency frames were most dominant; emphasizing a production-oriented approach that regards the environment as a natural resource base for food production but overlooks consumption and equity concerns. Despite strong support for the inclusion of ES considerations in the NFP, the influence of Australia\u27s socio-political context, powerful, industry-dominated stakeholders, and a reliance on traditional production-oriented perspectives delivered a business-as-usual approach to food policy making. It has since been replaced by an agricultural strategy that provides only cursory attention to ES. Our findings indicate that Australia\u27s political environment is not sufficiently mature for ES considerations to be integrated into food and nutrition policies. We propose reforms to the current consultation process in Australia to better support this integration by promoting greater transparency and participation in the development of food and nutrition policy making

Historical development of and paradigm shifts in public health nutrition

There is a bi-directional relationship between public health nutrition (PHN) and the environmental sustainability (ES) of food systems. Dietary guidelines provide evidence-based recommendations for healthy eating. There is significant variation towards the integration of ES considerations in these policies. An understanding of how and why this variation occurs is neede

Interaction of Seed Dispersal and Environmental Filtering Affects Woody Encroachment Patterns in Coastal Grassland

Encroachment of woody plants into grasslands has occurred worldwide and includes coastal ecosystems. This conversion process is mediated by seed dispersal patterns, environmental filtering, and biotic interactions. As spatiotemporally heterogeneous, harsh environments, barrier islands present a unique set of challenges for dispersal and establishment. Environmental conditions act as filters on dispersed seeds, thereby influencing encroachment and distribution patterns. Seldom have patterns of propagule dispersal been considered in the context of woody encroachment. We quantified dispersal and post‐dispersal processes of an encroaching woody population of Morella cerifera relative to directional rate of encroachment and observed distribution patterns on an Atlantic coastal barrier island with strong environmental filtering. We analyzed historic foredune elevation as a proxy for reduced interior environmental stress. The dispersal kernel was leptokurtic, a common characteristic of expanding populations, but rate of encroachment has slowed since 2005. Expansion pattern was related to foredune elevation, which limits encroachment below a threshold elevation. This difference between dispersal kernel behavior and encroachment rate is due to limited availability of suitable habitat for Morella and temporal variability in chlorides during the time of germination. Our results demonstrate that processes mediating seeds and seedling success must be accounted for to better understand establishment patterns of encroaching woody plants

Immunological and nutritional factors in elderly people in low-level care and their association with mortality

BACKGROUND: This study examines associations between markers of nutritional status and lymphocyte subsets and seeks to determine if lymphocyte profile is predictive of survival in elderly Australians residing in aged care facilities. Aged yet still ambulatory subjects (n = 88, 73% female) living in low-level care and requiring minimal assistance were studied for 143 weeks. At baseline when participants were aged (mean ± SD) 86.0 ± 5.9 years, dietary intake was determined by 3-day weighed food record, body composition was assessed by dual energy X-ray absorptiometry (DXA) and a venous blood sample was taken. RESULTS: At baseline assessment, study participants were consuming nutrient-poor diets and most had symptoms of chronic disease. Although overweight, 40% exhibited sarcopenia. Markers of nutritional status did not relate closely to immune cell numbers (absolute or relative), which on average were within the normal range. Men had lower numbers of CD3(+)CD4(+) cells (CD4(+) T cells), a higher proportion of CD3(−) CD16(±) CD56(±) (natural killer (NK) cells) and a higher ratio of NK: CD4(+) T cells than women (all P < 0.05). The main age-related changes evident were decreased T cells, particularly low CD4(+) T cell counts, and increased numbers of CD19(+) (B-cell) and NK cells. During the 143 week duration of follow-up, about one quarter of the study participants died, with death more likely in men than women (P < 0.01). Poor survival was predicted by the presence of decreased numbers of CD4(+) T cells (hazard ratio (HR) 0.919, P < 0.01) and expanded numbers of NK cells (HR 1.085, P < 0.05) in the blood, and therefore the presence of a high NK: CD4(+) T cell ratio (HR 30.521, P < 0.01). CONCLUSIONS: The NK: CD4(+) T cell ratio may potentially have clinical utility for predicting longevity in elderly populations. Further studies are needed in other elderly populations to confirm this finding

Audience Engagement in Theatre for Young Audiences: Teaching Artistry to Cultivate Tomorrow\u27s Theatre-Goers

As a teaching artist and theatre educator, I believe an important part of the theatre-going experience is when an audience engages with the play before and after the performance: learning about context, analyzing the production, and identifying themes relevant to the play. Theatre is a powerful teaching tool with regards to empathy and political and social awareness, but also, for young audiences, theatre can help students understand content in other subject areas like language arts, history, and even health. This thesis develops best practices for creating effective audience engagement with young people in theatre in the form of Field Trip Plus at Orlando Repertory Theatre, an enrichment program linking professional season productions to pre- and post-show workshops. It explores the following questions: What is audience engagement, and what are the benefits of audience engagement practices on retention and meaning-making? What is the history of audience engagement in Theatre for Young Audiences, and what are some examples of TYA companies intentionally engaging young people before and after performances? It focuses specifically on the development of Theatre-In-Education in the United Kingdom as an example of integrated drama and education practice which is supported by the pedagogy of Lev Vygotsky, Dorothy Heathcote, and Augusto Boal. It considers how the work of these theorists can also be applied to Field Trip Plus. This thesis is the personal exploration of a teaching artist practicing engagement strategies within Orlando Repertory Theatre, an established Theatre for Young Audiences, that will help young people make connections between state education standards and the play, cultivate their curiosity for learning through the arts, and become life-long active audience members