443 research outputs found
Vegetation and peat characteristics of restiad bogs on Chatham Island (Rekohu), New Zealand
Restiad bogs dominated by Sporadanthus traversii on Chatham Island, New Zealand, were sampled to correlate vegetation patterns and peat properties, and to compare with restiad systems dominated by Sporadanthus ferrugineus and Empodisma minus in the Waikato region, North Island, New Zealand. Classification and ordination resulted in five groups that reflected a disturbance gradient. The largest S. traversii group, which comprised plots from central, relatively intact bogs, had the lowest levels of total nitrogen (mean 1.20 mg cm-3), total phosphorus (mean 0.057 mg cm-3), total potassium (mean 0.083 mg cm-3), and available phosphorus (mean 18.6 μg cm-3). Modification by drainage, stock, and fires resulted in a decline of S. traversii and an increase of Gleichenia dicarpa fern cover, together with elevated peat nutrient levels and higher bulk density. Compared with peat dominated by Sporadanthus ferrugineus or Empodisma minus in relatively unmodified Waikato restiad bogs, Chatham Island peat under S. traversii has significantly higher total potassium, total nitrogen, available phosphorus, bulk density, and von Post decomposition indices, and significantly lower pH. Sporadanthus traversii and Empodisma minus have similar ecological roles in restiad bog development, occupying a relatively wide nutrient range, and regenerating readily from seed after fire. Despite differences in root morphology, S. traversii and E. minus are the major peat formers in raised restiad bogs on Chatham Island and in Waikato, respectively, and could be regarded as ecological equivalents
Manageable creativity
This article notes a perception in mainstream management theory and practice that creativity has shifted from being disruptive or destructive to 'manageable'. This concept of manageable creativity in business is reflected in a similar rhetoric in cultural policy, especially towards the creative industries. The article argues that the idea of 'manageable creativity' can be traced back to a 'heroic' and a 'structural' model of creativity. It is argued that the 'heroic' model of creativity is being subsumed within a 'structural' model which emphasises the systems and infrastructure around individual creativity rather than focusing on raw talent and pure content. Yet this structured approach carries problems of its own, in particular a tendency to overlook the unpredictability of creative processes, people and products. Ironically, it may be that some confusion in our policies towards creativity is inevitable, reflecting the paradoxes and transitions which characterise the creative process
Macrofossils and pollen representing forests of the pre-Taupo volcanic eruption (c. 1850 yr BP) era at Pureora and Benneydale, central North Island, New Zealand.
Micro- and macrofossil data from the remains of forests overwhelmed and buried at Pureora and Benneydale during the Taupo eruption (c. 1850 conventional radiocarbon yr BP) were compared. Classification of relative abundance data separated the techniques, rather than the locations, because the two primary clusters comprised pollen and litter/wood. This indicates that the pollen:litter/wood within-site comparisons (Pureora and Benneydale are 20 km apart) are not reliable. Plant macrofossils represented mainly local vegetation, while pollen assemblages represented a combination of local and regional vegetation. However, using ranked abundance and presence/absence data, both macrofossils and pollen at Pureora and Benneydale indicated conifer/broadleaved forest, of similar forest type and species composition at each site. This suggests that the forests destroyed by the eruption were typical of mid-altitude west Taupo forests, and that either data set (pollen or macrofossils) would have been adequate for regional forest interpretation.
The representation of c. 1850 yr BP pollen from the known buried forest taxa was generally consistent with trends determined by modern comparisons between pollen and their source vegetation, but with a few exceptions.
A pollen profile from between the Mamaku Tephra (c. 7250 yr BP) and the Taupo Ignimbrite indicated that the Benneydale forest had been markedly different in species dominance compared with the forest that was destroyed during the Taupo eruption. These differences probably reflect changes in drainage, and improvements in climate and/or soil fertility over the middle Holocene
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Genome-wide association study of primary open-angle glaucoma in continental and admixed African populations.
Primary open angle glaucoma (POAG) is a complex disease with a major genetic contribution. Its prevalence varies greatly among ethnic groups, and is up to five times more frequent in black African populations compared to Europeans. So far, worldwide efforts to elucidate the genetic complexity of POAG in African populations has been limited. We conducted a genome-wide association study in 1113 POAG cases and 1826 controls from Tanzanian, South African and African American study samples. Apart from confirming evidence of association at TXNRD2 (rs16984299; OR[T] 1.20; P = 0.003), we found that a genetic risk score combining the effects of the 15 previously reported POAG loci was significantly associated with POAG in our samples (OR 1.56; 95% CI 1.26-1.93; P = 4.79 × 10-5). By genome-wide association testing we identified a novel candidate locus, rs141186647, harboring EXOC4 (OR[A] 0.48; P = 3.75 × 10-8), a gene transcribing a component of the exocyst complex involved in vesicle transport. The low frequency and high degree of genetic heterogeneity at this region hampered validation of this finding in predominantly West-African replication sets. Our results suggest that established genetic risk factors play a role in African POAG, however, they do not explain the higher disease load. The high heterogeneity within Africans remains a challenge to identify the genetic commonalities for POAG in this ethnicity, and demands studies of extremely large size
A Qualitative Exploration of Factors Affecting Group Cohesion and Team Play in Multiplayer Online Battle Arenas (MOBAs)
Previous research examining the social psychology of video-gaming has tended to focus on Massively Multiplayer Online Role Playing Game (MMORPG) environments, such as World of Warcraft. Although many online group processes have been examined using this game, this genre does not enforce cooperative play and studies tend to be based on very large groups. Newer genres are being developed and played which have so far not been studied. The genre known as Multiplayer Online Battle Arenas (MOBAs) are attracting large numbers of players and success depends on effective team playing within smaller groups. The study reported here explores team play within MOBAs. Due to the lack of literature examining this genre, Corbin and Strauss’ (2008) Grounded Theory was used to analyse participants’ subjective experiences of playing MOBAs to create a conceptual model. A focus group pilot study informed the development of questions and then semi-structured interviews took place with twelve participants; 1 female and 11 male students aged between 18-21 years. Participants were required to have recent and frequent MOBA exposure, but with different preferences regarding roles and experience. Data was analysed using open, axial and selective coding and the resulting model depicts a scale, as optimal team performance was linked to a balance between factors. The core category “Communication” was heavily influenced by the relationship between teammates (friends or strangers). The balance of “Communication” affected the balance of the final three categories: “Team Composition”, “Psychological State” and “Level of Play”. The conceptual model is critically linked with traditional group processes, such as Belbin’s (1993) team roles, Tuckman’s (1965) model of group development and the perceptions and behaviour during the state of deindividuation (Taylor & MacDonald, 2002). The model has real-world application in both social and professional virtual environments, whilst contributing more broadly to research in Cyberpsychology and Social Psychology. Further research is suggested which will test predictions based on a predictive model
Synaptic phosphorylated a-synuclein in dementia with Lewy bodies
Dementia with Lewy bodies is characterized by the accumulation of Lewy bodies and Lewy neurites in the CNS, both of which are
composed mainly of aggregated a-synuclein phosphorylated at Ser129. Although phosphorylated a-synuclein is believed to exert
toxic effects at the synapse in dementia with Lewy bodies and other a-synucleinopathies, direct evidence for the precise synaptic
localization has been difficult to achieve due to the lack of adequate optical microscopic resolution to study human synapses. In the
present study we applied array tomography, a microscopy technique that combines ultrathin sectioning of tissue with immunofluorescence
allowing precise identification of small structures, to quantitatively investigate the synaptic phosphorylated a-synuclein
pathology in dementia with Lewy bodies. We performed array tomography on human brain samples from five patients with
dementia with Lewy bodies, five patients with Alzheimer’s disease and five healthy control subjects to analyse the presence of
phosphorylated a-synuclein immunoreactivity at the synapse and their relationship with synapse size. Main analyses were performed
in blocks from cingulate cortex and confirmed in blocks from the striatum of cases with dementia with Lewy bodies. A
total of 1 318 700 single pre- or post-synaptic terminals were analysed. We found that phosphorylated a-synuclein is present
exclusively in dementia with Lewy bodies cases, where it can be identified in the form of Lewy bodies, Lewy neurites and
small aggregates (50.16 mm3). Between 19% and 25% of phosphorylated a-synuclein deposits were found in presynaptic terminals
mainly in the form of small aggregates. Synaptic terminals that co-localized with small aggregates of phosphorylated a-synuclein
were significantly larger than those that did not. Finally, a gradient of phosphorylated a-synuclein aggregation in synapses
(pre4pre + post4post-synaptic) was observed. These results indicate that phosphorylated a-synuclein is found at the presynaptic
terminals of dementia with Lewy bodies cases mainly in the form of small phosphorylated a-synuclein aggregates that are
associated with changes in synaptic morphology. Overall, our data support the notion that pathological phosphorylated a-synuclein
may disrupt the structure and function of the synapse in dementia with Lewy bodies.Peer ReviewedPostprint (author's final draft
The adaptation of Chinese split-site business students to British classrooms: a cross-cultural perspective.
Research infrastructure challenges in preparing essential biodiversity variables data products for alien invasive species
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