Otago University Research Archive
Not a member yet
10699 research outputs found
Sort by
Reading the brain’s personality: using machine learning to investigate the relationships between EEG and depressivity
No full textElectroencephalography (EEG) measures electrical signals on the scalp and can give information about processes near the surface of the brain (cortex). The goal of our research was to create models that predict depressivity (mapping to personality in general, not just sickness) and to find potential biomarkers in EEG data. First, to provide our models with cleaner EEG data, we designed a novel single-channel physiology-based eye blink artefact removal method and a mains power noise removal method. Then, we assessed two main machine learning model types (classification- and regression-based) with a total of eighteen sub-types to predict the depressivity of participants. The models were generated by combining four signal processing techniques with a) three classification techniques, and b) three regression techniques. The experimental results showed that both types of models perform well in depressivity prediction and one regression-based model (Reg-FFT-LSBoost) showed a significant depressivity prediction performance, especially for female group. More importantly, we found that a specific EEG frequency band (the gamma band) made major contributions to depressivity prediction. Apart from that, the alpha and beta band may make modest contributions. Specific locations (T7, T8, and C3) made major contributions to depressivity prediction. Frontal locations may also have some influence. We also found that the combination of both eye states’ EEG data showed a better depressivity prediction ability. Compared to the eyes closed data, the EEG data obtained from the state of eyes open were more suitable for assessing depressivity. In brief, the outcomes of this research provided the possibilities for translating the EEG data for depressivity measure. Furthermore, there are possibilities to extend the research to apply to other mental disorders’ prediction, such as anxiety
Finding a Home. An Ecological and Economic Framework for Selecting Species Translocation Sites
No full textThe main objective of my thesis research was to improve our understanding of release site selection for conservation translocations, in particular how to identify quality habitat. To achieve this task, I developed four core research components. First, I reviewed the reintroduction literature to investigate the use of habitat and habitat- related terms in the context of species translocations. The findings of this chapter are further used to inform the theoretical framework of this thesis, which is centered around a species-specific habitat concept. Using the South Island Takahē (Porphyrio hochstetteri) as a case study, I then used geographic information systems and raster data to perform a landscape-level investigation of Takahē habitat quality throughout New Zealand. I applied expert-knowledge-informed spatial overlays and found that such a time- and cost-effective approach can be used as a first-stage investigation of candidate release sites with relative ease. The spatial overlays identified, in particular, the eastern foothills of New Zealand’s Southern Alps as areas of high Takahē habitat quality. Compared to the harsh alpine regions of the Alps, or the wet West Coast, the foothills are characterized by favorable climatic conditions, remoteness, and large expanses of tussock grassland. The applied methodology, while being coarse, can be used as a time- and cost effective first-stage screening of candidate release sites. In the fourth chapter I investigated micro habitat aspects, such as nutrient contents of palatables and micro climate around Takahē nest sites, to explain possible patterns in breeding success at the Takahē captive rearing facility near Te Anau. I found that this methodology can be used as a second- stage investigation of micro habitat for pre-selected candidate release sites. I was unable to detect any relationship between nutrient/ environmental parameters and patterns in breeding success. However, a single microhabitat site was identified as an outlier with particularly low breeding success in combination with low manganese contents. Previous research suggests that manganese deficiency can lower the productivity of birds. These findings justify a more-in-depth investigation of the corresponding breeding pen, its soil contents, water regime, and plant life. In the final step, I added an economic component to my research and developed a novel spatial approach to estimate habitat management costs, acquisition costs, and opportunity costs for candidate release sites. Using information such as land cover, distance to heliports, and slope, I investigated how landscape components affect the establishment and ongoing costs of planned species translocation sites. The main finding of this chapter was the existence of a trade-off between management costs of reintroduction sites and opportunity costs. Remote and rugged areas are more labor-intensive, but they have relatively low opportunity costs, decreasing the potential of human-wildlife conflicts. Further research could include an investigation of ecosystem services provided by reintroduction sites to assess both economic costs and within a common framework
Crucifixion and Sexual Abuse
No full textOriginally published in a longer version as David Tombs, ‘Crucifixion, State Terror, and Sexual Abuse’, Union Seminary Quarterly Review, 53 (Autumn 1999), pp. 89-109. Otago University Research Archive http://hdl.handle.net/10523/6067
This abridged version was first published in Portuguese as David Tombs, ‘Crucificação e abuso sexual’, Estudos Teológicos Vol. 59, No. 1 (July 2019), pp. 119-32; http://hdl.handle.net/10523/9848.This article draws on Latin American liberation hermeneutics to read the New Testament narratives of crucifixion in light of Latin American torture reports. The torture practices used by authoritarian regimes in Latin America in the 1970s and 1980s show how torture was used for state terror. Reports on this period also confirm the frequency of sexual violence in torture practices. Applying this perspective to a reading of the Gospel narratives, the article argues that the Romans also used crucifixion as state terror. Roman crucifixions were public punishments to intimidate and control slaves and subjected peoples. Furthermore, to reinforce the message of terror, crucifixions included sexual humiliation to degrade and demean their victims. The article argues that the stripping and naked exposure of Jesus recorded in the Gospels were a form of sexual humiliation and should be named as sexual abuse. It also raises a question on whether other sexual abuses might have taken place in the praetorium. It concludes that the possibility of further abuse is an important question to consider even though it cannot be answered with certainty
Ice shelf – ocean boundary interaction
No full textThermodynamic ablation of ice in contact with the ocean remains poorly understood. Consequently the main topic of this thesis is the interplay between the ice shelf-ocean boundary and the mechanisms driving ice shelf ablation. The rate of ablation is determined by the temperature, salinity and speed of the water that impinges the ice, and how this water transports heat to and from the ice-water interface. Both of these components are explored here as they are the key to understanding the long-term stability of Antarctica’s ice shelves.
The appearance of warm water in the Ross Ice Shelf cavity has recently been observed. To explain the process, we propose a novel mechanism for ice shelf front circulation. Direct contact of warm Antarctic Surface Water with the frontal wall of an ice shelf generates meltwater that rises along the vertical face and leads to formation of a ‘wedge’ of fresher water in front of the ice shelf, immediately adjacent to the wall. This wedge allows isopycnals to curve gently downwards, creating an efficient conduit by which warm surface waters enter the ice shelf cavity. Based on observational data from the Ross Sea and the Ross Ice Shelf cavity we demonstrate that the freshwater wedge is a pervasive feature of the Ross Sea in summer.
Consequences of the wedge circulation depend upon the details of thermodynamic interaction of inflowing ocean water and the ice shelf. We argue that classifications of ablation, initially developed for vertical interfaces, can be applied to the more common horizontal ice-ocean interfaces, typical of the base of an ice shelf. Four ablation types are defined based on two thermal regimes (melting and dissolving) and two turbulent flux regimes (shear-controlled and buoyancy-controlled regimes). We present the dominant processes expected next to ice interfaces of different orientations, and classify observational, modelling and theoretical studies of the ice-ocean boundary. We apply this classification to sets of observations from the Ross and Ronne Ice Shelf cavities.
Based on the ablation classification, we test ice-ocean ablation parameterisations for the most common ablation type: shear-controlled dissolving. To quantify uncertainties in ice shelf boundary parameterisations in an idealised ice shelf-ocean model, we undertake numerical experiments featuring 16 different formulations from the literature. Significant variability is found: the mean ablation rate in warm cavity scenarios varies between 2.1 and 4.7 m year-1, and in cold cavity scenarios between 0.03 and 0.17 m year-1. The different behaviours relate to differences in modelled ocean boundary layer stratification, highlighting an existing observational uncertainty of ice- ocean boundary layer processes.
Recognising that warm surface water can easily enter the Ross Ice Shelf cavity, understanding how this heat is translated into basal ablation is a challenge. New approaches to ablation parameterisations have been presented, and existing ablation parameterisations have been tested against in situ observations
Understanding the “who” in conservation: why gender matters
No full textEnvironmental management and conservation practices are at their core greatly affected by who is making the decisions for how to manage and address issues. Thus, it is of great importance to understand how the makeup of conservation decision making bodies affects environmental management processes and practices. This research looks at how gender factors into the environmental management space through the investigation of the major overarching question: In what way(s) does gender play a role in conservation / environmental decision making in a developed country context? In particular, it asks: 1) what is the representation of men and women in conservation leadership in New Zealand, 2) how, if at all, do male and female practitioners differ in their environmental values, priorities and strategies for management, and 3) how does gender factor into the decision making space and its processes? To answer these questions, a sample of five large national and seven small local Dunedin-area organizations were selected based on their significance nationally or locally. Secondary data on gender representation by tier (i.e. upper level executive to low-level job position) was procured through contact with each organization, and interviews were conducted with 32 executive members of these organizations. Additionally, a survey aimed at understanding gender differences in conservation values, priorities, and strategies was distributed to employees of various environmental organizations across the country. Results demonstrate that women make up a large portion of conservation organizations generally but a small portion of leadership roles. Male and female practitioners overall are quite similar in ideology with a few important exceptions such that increasing female leadership presence in conservation may lead to increases in indigenous iwi involvement, education investment, regulation of mining and forestry practice, length of deliberation on issues, cautiousness in approach, openness to ideas, and overall communication. Women’s inclusion also appears to affect the work environment of conservation organizations through increasing focus on more interpersonal and “human” aspects. All in all, this research provides an extensive discussion of the representation of women in conservation, gender dimensions of conservation ideology, and gender dimensions of the conservation work environment, providing a strong argument in favor of increasing gender equity in conservation leadership
Life in utopia? An ethnography of tourism-related lifestyle migrants in Dali, China
No full textLifestyle migration is a relatively new phenomenon that has attracted academic attention since the late 20th century. Lifestyle migration is associated with affluent societies, and as a result, previous studies on this topic are mainly Western-oriented. Benefiting from economic reform, China has experienced an economic boom since 1979. Accordingly, lifestyle migration has increased in popularity in the last two decades. The tourism industry plays a very important role in this process. It not only constructs and markets a “better” lifestyle for the potential migrants, but also offers them a feasible and attainable way to achieve it. In contemporary China, opening a hostel or coffee shop in a tourism destination is regarded as an ideal lifestyle among many young people. Attaining such a lifestyle usually involves migrating from a large city to a small town or village and setting up a small independent tourism business there. The main motivation for this behavior appears to be a search for a better way of life rather than making financial profits.
In this thesis, these migrants are called “tourism-related lifestyle migrants” (TLMs), and the aim of this research is to explore this new subculture in China. Ethnography, which took a mixed stance of hermeneutics and critical epistemology, was used to understand the life of these TLMs. A six months period of fieldwork was undertaken from May to October 2017 in Dali, China, which is one of the target destinations for Chinese TLMs. Participant observation, interviewing, and some other visual and textual sources were adopted as information-gathering methods.
This thesis demystifies the so-called “better life” of TLMs in Dali as a mix of the good and the dark. The everyday practice of TLMs itself can be seen as their embodiment of the imagined good life as well as the critique of the dark side of modern urban life, while the frustration of these endeavors, again, echoes the discourse of the dark. Thus, a critical question is asked: How is the life sought by Chinese TLMs (not) achievable? This question is answered based on a dualism between the making and the disillusioning of utopia. While the former highlights both discursive and non-discursive practice of TLMs, the latter focuses on the role of political and capital power in this process.
By situating this new subculture into the context of individualization and modernization in contemporary Chinese society, the thesis argues that TLM is seen as a way, especially by young Chinese, to resist the nihilism caused by the current failure of social re-embedment of individuals. However, the external conditions and internal contradictions in TLM eventually expose the attempt to create a better life for themselves in “utopia” as largely futile
Zinc intakes and food sources in vegetarian compared to non-vegetarian adolescent females in New Zealand
No full textBackground: The number of individuals choosing to follow a vegetarian, or reduced meat, diet is thought to be increasing in high income countries such as New Zealand. Consuming a vegetarian diet with adequate macro- and micro-nutrients is achievable, however a vegetarian diet needs to be appropriately planned. The adequacy of zinc intake, in particular, has been reported to be lower in those following a vegetarian diet. This is due to both the exclusion of flesh foods, a rich source of bioavailable zinc, and due to higher intakes of food components that have an inhibitory effect on zinc absorption in vegetarian diets. This is of concern due to the plethora of roles zinc plays in the body, including in the immune system and numerous metabolic pathways. It also plays an important role in growth and development as individuals progress from childhood to young adulthood. However, data comparing the zinc intakes of vegetarian and non-vegetarian adolescent females do not exist in New Zealand.
Objective: To compare the zinc intakes, adequacy of zinc intake, and food sources of zinc in healthy adolescent female vegetarians and non-vegetarians in New Zealand. Design: The SuNDiAL (Survey of Nutrition, Dietary Assessment, and Lifestyle) project was a cross-sectional, observational study. Participants were recruited throughout New Zealand through high schools, or recruitment targeted at vegetarians. Participants were females 15 to 18 years of age who were asked to self-identify as either vegetarian or non-vegetarian.
Methods: Online questionnaires were completed to gather demographic and lifestyle information. Two 24-hour diet recalls were used to collect dietary data: one face-to-face, with a second non-consecutive one collected via telephone. The second diet recall was to allow usual intake to be calculated using the Multiple Source Method (MSM). The diet recalls were entered into, and analysed, in FoodWorks, a dietary assessment software programme which uses NZ food composition tables to calculate nutrient intakes. The prevalence of inadequate intake was determined using the estimated average requirement (EAR) cut-point method.
Results: The Candidate’s analysis comprised 250 participants: 31 vegetarians and 219 non-vegetarians. Zinc intake on average was 7.5mg and 9.5mg per day for vegetarians and non-vegetarians, respectively. This difference of -2.0mg/day was statistically significant. Using the EAR cut-point method with an EAR at 6mg per day, 16.1% of the vegetarians were observed to be at risk of inadequate intake compared to 6.4% in the non-vegetarian group. However, when the EAR was increased to 9mg per day based on recommendations for strict vegetarians, 80.6% of the vegetarians had an inadequate intake. The ‘grains and pasta’ food group provided the highest proportion of zinc in the diets of both groups. The vegetarians were consuming more zinc (15.2%) from ‘vegetables’ than the non-vegetarians (6.6%).
Conclusion: When using an EAR recommended for those following a vegetarian diet, a large proportion of the vegetarian group had inadequate intake which warrants further investigation. This indicates vegetarians may be at a higher risk of having inadequate zinc status. Further research into the biochemical zinc status of vegetarians will give more insight into the risk of deficiency
Dissecting alterations to arcuate nucleus neuropeptide Y neural circuitry in a model of polycystic ovary syndrome
No full textPolycystic ovary syndrome (PCOS) is the most common form of infertility among women of reproductive age. Despite the prevalence of PCOS, the underlying mechanisms behind how PCOS arises and causes infertility remain poorly understood. While primarily considered a disorder of the ovary, a growing body of evidence suggests that PCOS is associated with dysfunctional neuroendocrine circuitry in the hypothalamus that orchestrates gonadotrophin hormone secretion. Women with PCOS frequently exhibit rapid pulsatile luteinizing hormone (LH) secretion. While LH secretion is tightly regulated by ovarian steroid hormonal feedback in fertile women, women with PCOS are unresponsive to these hormones. Elevated LH secretion likely reflects dysfunctions to the gonadotropin-releasing hormone (GnRH) neuronal network in the hypothalamus that gates LH secretion and integrates steroid hormone feedback. As GnRH neurons themselves do not express the receptors necessary for feedback to occur, research has sought to identify alterations to GnRH neural afferents that may arise in PCOS.
Prior work within our lab has utilized a prenatal androgen (PNA) treated mouse model of PCOS to identify enhancement of excitatory GABAergic inputs to GnRH neurons. In particular, GABA neurons in the hypothalamic arcuate nucleus (ARN) have been identified with enhanced input to GnRH neurons, and reduced sensitivity to an ovarian steroid hormone, progesterone. Neuropeptide Y (NPY) neurons compose a large proportion of GABA neurons within the ARN, and are known to play an important role in restraint of LH secretion via inhibition of GnRH neurons. Interestingly, plasma NPY is often reduced in women with PCOS, indicating impairment of its neural secretion. The overarching aim of work presented in this thesis was therefore to determine whether NPY neurons within the ARN also exhibit PNA-induced alterations, which may advance our understanding of how unrestrained LH secretion occurs in PCOS.
Initially, the proportion of NPY neurons that are GABAergic within the ARN was assessed by pairing immunohistochemical (IHC) labelling of NPY with transgenic reporter identification of GABA neurons, in both PNA-treated mice and fertile controls. Additionally, the molecular identity of ARN GABA neurons was further dissected to assess whether they express other peptides known to regulate GnRH neurons. This work established that ARN NPY neurons compose approximately one-third of ARN GABAergic neurons, a far larger proportion than any other neural phenotype examined, and demonstrated that the vast majority (> 93%) of ARN NPY neurons are GABAergic. While fertile male mice were observed to have a larger population of ARN NPY neurons compared with both fertile (p = 0.0006) and PNA-treated females (p = 0.0192), no differences were found between female groups, indicating the size of this population is not masculinized by PNA-treatment.
To investigate remodelling of NPY neurons in the ARN specifically, the validity of an agouti-related peptide (AgRP)-Cre mouse line was characterised as AgRP is highly co-expressed with NPY, and exclusively expressed in the ARN. After crossing AgRP-Cre mice onto a Cre-dependant GFP reporter it was demonstrated that within the ARN, GFP reporter was highly specific and effective at identifying NPY neurons. Additionally, GFP expression was overwhelmingly confined to the ARN only. Whole brain mapping of axon-associated GFP expression revealed that this reporter was highly effective for visualising distal axons. In order to assess whether ARN NPY neurons projecting to GnRH neurons could be targeted more specifically, a fluorescent retrograde tracer was injected into the preoptic area where the majority of GnRH neurons reside. This revealed that approximately 10% of ARN NPY neurons project to the area where GnRH neurons are located, and that these neurons are scattered throughout the ARN rather than composing an anatomically defined population. These experiments demonstrated that AgRP-GFP mice are an appropriate model for further dissection of ARN NPY neurons.
Using this model, the hypothesis that PNA exposure leads to remodelling of ARN NPY sensitivity to steroid hormones, and their projections to GnRH neurons was addressed. Interestingly, ARN NPY neurons did not express the progesterone receptor or estrogen receptor . However, a greater proportion of ARN NPY neurons expressed androgen receptor (AR) in PNA mice compared with fertile controls (p = 0.045). When close appositions between ARN NPY axons and GnRH neurons was examined, indicating putative innervation, it was revealed that there were no differences in the close appositions onto GnRH neurons in the PNA-treated mouse. Overall, these results suggest that ARN NPY neurons are not remodelled in the same way as ARN GABA neurons, but are subject to their own distinct alterations in PNA-treated mice in the form of elevated androgen sensitivity.
The role of leptin, a major regulator of ARN NPY neurons and permissive cue in fertility, was then examined in PNA-treated mice compared to fertile controls. Plasma leptin was measured in fed and fasted states, and there were no differences in leptin levels in PNA-treated mice. Interestingly, fasting reduced plasma leptin in PNA-treated mice similar to controls, contrasting previous findings indicating derangements to fasted leptin levels. Furthermore, leptin responsiveness indicated by induction of pSTAT3 was not different in PNA-treated mice. These results indicate that leptin signalling in the ARN is normal in PNA-treated mice and leptin acting within this region is not likely to contribute to altered GnRH neuron activity.
While ARN NPY neurons and circuitry were found to be largely unaffected by PNA-treatment, a sensitive NanoString assay for gene expression revealed evidence for potential reductions in downstream signalling within hypothalamic regions important for GnRH neural regulation. Expression of the NPY Y1 receptor was downregulated in the rostral periventricular region of the third ventricle, a region important for generating the preovulatory LH surge. Additionally, a sizable reduction in leptin receptor gene expression was observed in the preoptic area in the vicinity of GnRH neurons, an area in which leptin signalling plays a role in regulating LH secretion.
Taken together these results do not support the hypothesis that alterations within ARN NPY-to-GnRH neuron circuitry plays a major role underpinning neuroendocrine disruption in PNA-treated mice and PCOS. While ARN NPY neurons do not appear to compose a subset of ARN GABA neurons that are remodelled following PNA-treatment, elevated androgen sensitivity was identified. As androgens disrupt negative feedback in PCOS, this opens up the possibility that androgens act via ARN NPY neurons to disrupt appropriate response by other steroid hormone sensitive afferent populations. Differences in NPY receptor expression were discovered in hypothalamic regions important for regulation of GnRH neurons, and potentially indicates altered NPY signalling within the GnRH afferent network. These findings establish a platform upon which future research will elucidate the importance of these circuit alterations in generating neuroendocrine disruptions in PCOS
The Trees’ Influence on Soil Development. Nutrient Cycling Strategies of Trees. Fundamental Knowledge for synecological Forest Ecosystem Management.
No full textThe influence of various tree species and -genera on an initially homogenous soil substrate has been analysed and compared.
The homogeneity of the site is due to a common loessial soil substrate, a narrow topographical and climatical range, the prehistoric lowland forest cover and an equivalent subsequent history with clearance of the indigenous vegetation, followed by reafforestation around the turn of the century.
The trees were located at random and soil samples were taken, half way between the trunk and the drip lines at four locations and at three depths within the soil A-horizon.
The four sample locations around each tree were pooled and the three depths at 0-1 cm; 7-8 c; 14-15 cm were subsequently analysed for:
pH; cation exchange capacity; contents of the base cations (Ca; Mg; K; Na); phosphorus; and soil organic matter,
specifically carbon, nitrogen and the humic matter fractions, including an elemental analysis (C, N and H) of the humic fractions.
For each depth level, these soil parameters (except elemental contents of the humic fractions) were subjected to statistical analyses (Principal Component Analysis, P.C.A.; Cluster Analysis, C.A.), which grouped individual trees into two related groups and one sign ificantly different group according to their influence on the soil.
Analyses of Variance established hypotheses with regard to group specific nutrient cycling strategies.
A correlation analysis of all soil parameters and a regression analysis of two soil parameters aided with the interpretation of the ordination results.
An elemental analysis of the humic fractions showed diffrenences in structure and the elemental allocation, dependent on the phanerophyte input and soil depth.
The first two P.C.A. derived groups,
New Zealand Indigenous Trees (Dacrydium cupressinum, Prumnopitys ferruginea, P. taxifolia, Nothofagus fusca, N. solandri, N. truncata, Plagianthus regius, Sophora microphylla, Kunzea ericoides) and Exotic Deciduous Trees (Acer pseudoplatanus, Aesculus hippocastanum, Fagus sylvatica, Fraxinus excelsior, Quercus canariensis, Q. robur, Q. rubra, Tilia europaea, Ulmus procera, Ulmus x hollandica) have in common a strategy that increases the nutrient storage capacity and which favours the cycling of nutrients in the soil medium.
Individual vigours in the cycling of nutrients and the creation of nutrient storage acpacity towards one or the other soil humus type are indicated by the ordinations, specifically the C.A.
The histograms, the correlation and regression analyses of soil parameters demonstrate,the presence of specific strategic and amplitudinal distinctions in creating storage capactiy and the cycling of nutrients, that, based on site homogeneiety are independent from the quality of the mineral substrate.
Trees from both groups show convergences and specifc inherent contributions towards the genesis of soil nutrient storage capacity and the cycling of nutrients.
A third group is significantly different from the indigenous and deciduous groups and includes the following trees: Pinus radiata, Pseudotsuga menziesii, Larix decidua, Eucalyptus regnans. A tight clustering in the ordinations, comparison with the mineral substrate reserves, the analyses of variance, soil parameter correlation and -regression analyses demonstrate a common strategy based on the extraction of nutrients from the soil.
Nutrient extraction strategeis facilitate survival in harsh environments of their natural habitats. These trees have in common an adaptation to recurring events of disturbance, often caused by fire, which is fuelled by a litter load that resists decomposition.
An ecological term describes these as Pyrophanerophytes (Fire Trees).
Fre trees tend to form stands of little species diversity.
The common transplantation of fire trees to forest-soil systems, that were based on nutrient cycling and consequently attained large soil nutrint stores will have the following consequences:
1) The growth of fire trees is faster than in their natural habitats.
2) A de-coupling of the nutrient cycling process ensues.
3) Pyrophanerophyte litter leachates and root exudates lead to the effective decomposistionof clay minerals and deminishes mineral nutrient reserves.
4) Soil organic nutrient stores may be decomposed and serve as a source of N (de-coupling of the nitrogen cycle)
5) The storage decrease due to the loss of soil organic matter diminishes the cation exchange capacity and the nutrient storage capacity.
6) Artificial fertilisation will rapidly lose effectiveness.
7) The resulting potential for soil acidification is considerable and the soil buffer capacity may rapidly degrade to the aluminium / iron buffer range.
8) The loss of soil organic matter and biological activity may lead to a compacted physical soil structure.
These effects result in a rapid degeneration to a podzol and are the main reasons why evolution did not lead to the dominance of firetree species, since fire trees would naturally eliminate themselves by rapidly changing the soil state.
Fire trees are alien to a New Zealand oceanic-temperate forest ecosystem.Widespread commercial forestry, based on pyrophanerophytes (fire trees) is unsustainable.
The strategies of trees from the indigenous or exotic deciduous forests show a common ecosystem strategy, based on the creation and maintenance of nutrient storage capacity and the cycling of nutrients in the soil medium, which provides the basis for a long-term potential for yield and the sustainable management of productive forests
Beyond the DSM-5: Examining the effects of processing speed and working memory on ADHD symptoms and adaptive functioning
No full textChildren with Attention Deficit Hyperactivity Disorder (ADHD) not only exhibit significant variability in the impulsive and hyperactive symptoms that characterise the diagnosis, but also in the presence and severity of impairment necessary to meet diagnostic criteria, such as adaptive functioning. An investigation of the mechanisms underlying this heterogeneity is paramount to provide effective interventions. Impaired working memory and processing speed have been shown to be associated with both ADHD symptoms and adaptive functioning. As such, the present study investigated the association between symptoms of ADHD, adaptive functioning, processing speed and working memory, before examining whether the latter two variables mediate the relationship between ADHD symptoms and adaptive functioning. Participants in this study included 103 children aged 6 – 12 years, 35 of whom were formally diagnosed with ADHD. ADHD symptom severity was assessed using the KSADS-PL, adaptive functioning was measured using combined teacher and parents’ ratings on the BASC-3, and the WISC-V assessed processing speed and working memory. In line with the hypotheses, the results showed that a greater percentage of children with ADHD displayed impairment in adaptive functioning, processing speed, and working memory compared to typically developing children. Significant correlations were found between all study variables, except between processing speed and hyperactive symptoms, adaptability, social skills, and functional communication. Bias-corrected, bootstrapped mediation analyses showed that working memory, but not processing speed, partially mediated the relationship between ADHD symptoms and adaptive functioning, suggesting that working memory should be assessed and addressed within the treatment of ADHD to reduce adaptive functioning impairment