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Weak coordination among petiole, leaf, vein, and gas-exchange traits across Australian angiosperm species and its possible implications
No full textClose coordination between leaf gas exchange and maximal hydraulic supply has been reported across diverse plant life forms. However, it has also been suggested that this relationship may become weak or break down completely within the angiosperms. We examined coordination between hydraulic, leaf vein, and gas-exchange traits across a diverse group of 35 evergreen Australian angiosperms, spanning a large range in leaf structure and habitat. Leaf-specific conductance was calculated from petiole vessel anatomy and was also measured directly using the rehydration technique. Leaf vein density (thought to be a determinant of gas exchange rate), maximal stomatal conductance, and net CO₂ assimilation rate were also measured for most species (n = 19–35). Vein density was not correlated with leaf-specific conductance (either calculated or measured), stomatal conductance, nor maximal net CO₂ assimilation, with r² values ranging from 0.00 to 0.11, P values from 0.909 to 0.102, and n values from 19 to 35 in all cases. Leaf-specific conductance calculated from petiole anatomy was weakly correlated with maximal stomatal conductance (r² = 0.16; P = 0.022; n = 32), whereas the direct measurement of leaf-specific conductance was weakly correlated with net maximal CO₂ assimilation (r² = 0.21; P = 0.005; n = 35). Calculated leaf-specific conductance, xylem ultrastructure, and leaf vein density do not appear to be reliable proxy traits for assessing differences in rates of gas exchange or growth across diverse sets of evergreen angiosperms.12 page(s
Slowing the progression of age-related hearing loss : rationale and study design of the ASPIRIN in HEARING, retinal vessels imaging and neurocognition in older generations (ASPREE-HEARING) trial
No full textBackground: Age-related hearing loss (ARHL) is a leading cause of disability in the elderly. Low-grade inflammation and microvessel pathology may be responsible for initiating or exacerbating some of the hearing loss associated with aging. A growing body of evidence demonstrates an association of hearing loss with cognitive decline. A shared etiological pathway may include a role of inflammation, alongside vascular determinants. The ASPREE-HEARING study aims to determine whether low-dose aspirin decreases the progression of ARHL, and if so, whether this decrease in progression is also associated with retinal microvascular changes and/or greater preservation of cognitive function. Design and methods: A three year double-blind, randomized controlled trial of oral 100 mg enteric-coated aspirin or matching placebo, enrolling 1262 Australians aged ≥ 70 years with normal cognitive function and no overt cardiovascular disease. The primary outcome is the change in mean pure tone average hearing threshold (decibels) in the better ear, over a 3-year period. Secondary outcomes consist of changes in retinal microvascular indicators, and changes in cognitive function. Participants are recruited from a larger trial, ASPirin in Reducing Events in the Elderly (ASPREE), which is designed to assess whether daily low dose aspirin will extend disability-free life. Discussion: ASPREE-HEARING will determine whether aspirin slows development or progression of ARHL, and will interrogate the relationship between inflammatory and microvascular mechanisms that may underlie the effects of aspirin on ARHL. This study will improve understanding of the patterns of comorbidity with, and the relationships between, aging and ARHL, alongside modeling the impacts of ARHL.7 page(s
A Scottish inheritance? Mary Bennett, the Aboriginal cause and the legacies of the past
No full textMary Montgomerie Bennett (1881–1961) was a leading twentieth century advocate for Aboriginal human rights. Her advocacy has been explored in the context of Christian reformism, feminism and humanitarianism. In this paper, I look towards her Scottish origins—and her family—as a way of exploring her extraordinary commitment to this cause. While mapping out the terrain of her advocacy I show how her family story is crucial, including its Scottish roots, and argue that her Scottish inheritance is evident in her attitudes on the question of 'race' and racial justice, as well as her teaching of Indigenous students and her unswerving faith.26 page(s
Perforator mapping and optimizing design of the lateral arm flap : anatomy revisited and clinical experience
No full textBackground: The lateral arm flap remains an underused flap, especially as a free flap. In this article, the authors describe the perforator anatomy to optimize flap design and harvest. Methods: Perforator locations were mapped in 12 cadavers (24 arms), and a retrospective review was conducted of 51 patients undergoing lateral arm flap surgery. Results: One to three reliable perforators supply the lateral arm flap. Based on cadaveric dissections, from the deltoid insertion, the A, B, and C perforators were located at 7.2 ± 1.0 cm, 9.9 ± 1.2 cm, and 11.8 ± 0.8 cm, which was 0.44, 0.61, and 0.72 of the distance from the deltoid insertion, respectively. The average pedicle length was 7.0 ± 1.1 cm. The cadavers were entirely symmetric in the number and location of the perforators between the right and left arms. All 51 patients (24 male and 27 female patients) had at least one perforator with an average pedicle length of 7.0 ± 1.3 cm, an average arterial diameter of 1.7 ± 0.3 mm, and a vein diameter of 2.5 ± 0.5 mm. All but one flap was performed as a free flap for head and neck reconstruction, with one pedicled flap for shoulder reconstruction. The average flap size was 72.2 ± 37.1 cm (range, 21 to 165 cm). The nondominant arm was used for all free flaps. There were no total or partial flap losses. Twenty-eight patients reported donor-site numbness, with one infection, one hematoma, and one wound dehiscence. Conclusion: The lateral arm flap can be harvested reliably based on well-defined perforators and anatomical landmarks with minimal donor-site morbidity and should be included among the techniques used by reconstructive microsurgeons.7 page(s
The Effect of functional hearing and hearing aid usage on verbal reasoning in a large community-dwelling population
No full textObjectives: Verbal reasoning performance is an indicator of the ability to think constructively in everyday life and relies on both crystallized and fluid intelligence. This study aimed to determine the effect of functional hearing on verbal reasoning when controlling for age, gender, and education. In addition, the study investigated whether hearing aid usage mitigated the effect and examined different routes from hearing to verbal reasoning. Design: Cross-sectional data on 40- to 70-year-old community-dwelling participants from the UK Biobank resource were accessed. Data consisted of behavioral and subjective measures of functional hearing, assessments of numerical and linguistic verbal reasoning, measures of executive function, and demographic and lifestyle information. Data on 119,093 participants who had completed hearing and verbal reasoning tests were submitted to multiple regression analyses, and data on 61,688 of these participants, who had completed additional cognitive tests and provided relevant lifestyle information, were submitted to structural equation modeling. Results: Poorer performance on the behavioral measure of functional hearing was significantly associated with poorer verbal reasoning in both the numerical and linguistic domains (p < 0.001). There was no association between the subjective measure of functional hearing and verbal reasoning. Functional hearing significantly interacted with education (p < 0.002), showing a trend for functional hearing to have a greater impact on verbal reasoning among those with a higher level of formal education. Among those with poor hearing, hearing aid usage had a significant positive, but not necessarily causal, effect on both numerical and linguistic verbal reasoning (p < 0.005). The estimated effect of hearing aid usage was less than the effect of poor functional hearing. Structural equation modeling analyses confirmed that controlling for education reduced the effect of functional hearing on verbal reasoning and showed that controlling for executive function eliminated the effect. However, when computer usage was controlled for, the eliminating effect of executive function was weakened. Conclusions: Poor functional hearing was associated with poor verbal reasoning in a 40- to 70-year-old community-dwelling population after controlling for age, gender, and education. The effect of functional hearing on verbal reasoning was significantly reduced among hearing aid users and completely overcome by good executive function skills, which may be enhanced by playing computer games.11 page(s
Trace element composition and Lu-Hf isotope systematics of zircon from plagiogneisses of the Kola superdeep well : contribution of a Paleoarchean crust in mesoarchean metavolcanic rocks
No full textZircons have been studied in three samples of Archean plagiogneisses from the Kola superdeep well (SG-3). The crystals consist of cores, magmatic shells, and metamorphic rims. The cores and shells are characterized by similar lowered concentrations of most trace elements, which is typical of zircons from plagiogranitoids, rocks of elevated basicity, and basites. At a wide range of Hf isotope characteristics, the cores and shells have similar average ¹⁷⁶Hf/¹⁷⁷Hfi, which determines the close composition of their sources. The metamorphic rims have close ¹⁷⁶Hf/¹⁷⁷Hfi ratio. The minimum age of the crustal contaminant of parental melts is estimated at 3.4 and 3.3 Ga for cores and 3.3–3.2 Ga for shells at almost equal proportions of mantle and crustal components in them. The contribution of Paleoarchean crust established in zircons from plagiogneisses of SG-3 using Lu-Hf isotope systematics is confirmed by the presence of 3.3and 3.4-Ga old zircons in surrounding TTG.20 page(s
The Cognitive integration of scientific instruments : information, situated cognition, and scientific practice
No full textResearchers in the biological and biomedical sciences, particularly those working in laboratories, use a variety of artifacts to help them perform their cognitive tasks. This paper analyses the relationship between researchers and cognitive artifacts in terms of integration. It first distinguishes different categories of cognitive artifacts used in biological practice on the basis of their informational properties. This results in a novel classification of scientific instruments, conducive to an analysis of the cognitive interactions between researchers and artifacts. It then uses a multidimensional framework in line with complementarity-based extended and distributed cognition theory to conceptualize how deeply instruments in different informational categories are integrated into the cognitive systems of their users. The paper concludes that the degree of integration depends on various factors, including the amount of informational malleability, the intensity and kind of information flow between agent and artifact, the trustworthiness of the information, the procedural and informational transparency, and the degree of individualisation.21 page(s
Optimal portfolios with maximum Value-at-Risk constraint under a hidden Markovian regime-switching model
No full textThis paper studies an optimal portfolio selection problem in the presence of the Maximum Value-at-Risk (MVaR) constraint in a hidden Markovian regime-switching environment. The price dynamics of n risky assets are governed by a hidden Markovian regime-switching model with a hidden Markov chain whose states represent the states of an economy. We formulate the problem as a constrained utility maximization problem over a finite time horizon and then reduce it to solving a Hamilton–Jacobi–Bellman (HJB) equation using the separation principle. The MVaR constraint for n risky assets plus one riskless asset is derived and the method of Lagrange multiplier is used to deal with the constraint. A numerical algorithm is then adopted to solve the HJB equation. Numerical results are provided to demonstrate the implementation of the algorithm.12 page(s
First person narratives and third-wave feminism: raising consciousness or the mother of a guilt trip?
No full textTheoretical thesis.Bibliography: pages 87-91.Introduction. From The feminine mystique to pill-pop culture -- One. The ecstasy of empathy-- Two. What drug is he on? -- Three. Now mother is mother's little helper -- Four. Tripping off and up on the normative parenting grid -- Conclusion. Selling feminism or selling out feminism?More than half a century after Betty Friedan’s The Feminine Mystique and forty years after Anne Summers’ Damned Whores and God’s Police raised alarms about the levels of prescription drug use among women in America and Australia, respectively, two high profile Australian journalists and feminists, Lisa Pryor and Mia Freedman, wrote personal columns about juggling work and family, and dealing with mental health issues through consuming anti-depressant and anti-anxiety medication. While second-wave feminists used the personal story form in the practice of consciousness raising, how do these contemporary writers – women who I argue are representative of third-wave feminism – use the personal story form? I argue that the personal story form in these contemporary examples has some parallels with the consciousness raising practice associated with second-wave feminism: it opens up a space for creating empathy and identification, and allows writers and readers to discursively create contradictory and ambiguous maternal subjects. At the same time, I suggest the use of the first person in the mainstream media also exposes feminists to particularly harsh and personal criticisms that appear specifically reserved for women and mothers. I also consider the way the personal voice in these contemporary stories both reinforces post-feminist and neoliberal constructions of women as empowered and responsible for juggling all spheres of life, and tasked with constantly adapting and improving themselves, while – seemingly paradoxically and somewhat contradictorily – simultaneously challenging idealised notions of motherhood through (limited) representations of aberrant mothering.Mode of access: World wide web1 online resource (91 pages
A direct realist understanding of memory errors
No full textTheoretical thesis.Bibliography: pages 140-175.Introduction -- Chapter One. Anti-representationalism and realism -- Chapter Two. Situational realism -- Chapter Three. The problem of memory -- Chapter Four. The problem of error -- Chapter Five. A contribution to the realist understanding of memory errors -- Conclusion.Memory errors are part and parcel of everyday remembering. While memory and errors in general, present as some of strongest evidence in support for representationalism, memory and error are also two of bigger challenges for direct realism. In fact, critics regard both memory and errors as insurmountable logical problems for direct realism, which makes memory error a unique challenge for direct realism.With regards to memory, firstly, the problem is if the direct realist claims that remembering is a direct relation to a past event, how does the subject who is engaged in the present act of remembering have direct relation to a past event that no long exists? With regard to error, the problem is that if there is a direct relation to the object of cognition as direct realism claims then what is the object of cognition when we are in error? In the case of memory errors then, the challenge is that not only is the act of remembering taking place separate from the initial time the event has occurred but the direct realist needs also to account for how the subject, who has a direct independent relation to the event, can be mistaken about the past event he or she is remembering.The present thesis aim is to take steps to show how direct realist will take the first steps to address the problems of memory error. It will be shown that a variety of direct realism known as situational realism that defines psychology as the study of organism environmental relations and the interactions involving cognition, emotion, and motivation will be able to address the challenges. It will be argued that it is only by taking into consideration both memory and error together that a greater sense of error can be understood from a direct realist perspective.Mode of access: World wide web1 online resource (175 pages