200 research outputs found

    Using marine ecoengineering to mitigate biodiversity loss on modified structures in the Waitematā Harbour : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Albany, New Zealand

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    The construction of infrastructure on the foreshore is an unavoidable consequence of an ever-expanding human population. Traditionally, this infrastructure has replaced softsubstrates with hard substrates. Furthermore, even for native biota which occupy hard substrates, the flat, featureless construction of most marine infrastructure provides little habitat heterogeneity and results in depauperate communities with little biotic resistance against non-indigenous species. Marine ecoengineering provides a possible solution to this global phenomenon by using intelligent construction techniques that promote the accumulation of native biodiversity. Here, I used eco-engineered settlement plates to examine the effect of habitat complexity on the biodiversity of communities inhabiting existing. Additionally, we examined the effects of climate change driven increases in rainfall on the performance of ecoengineered substrates in the mid-intertidal zone. Last, we reviewed and synthesised the available literature on the species present in The Waitematā Harbour and, to the best of my knowledge, provide the most complete species lists to date. In chapter two, we transplanted eco-engineered settlement plates seeded with local bivalve, Perna canaliculus, onto an existing seawall and monitored the accumulation of biodiversity. Overall, we show that both structural and biological habitat heterogeneity enhanced the biodiversity of the seawall community. Additionally, we found that the cemented pavement of volcanic rock that constituted the existing seawall, accumulated biodiversity faster than flat concrete settlement plates, supporting the use of this type of seawall construction over flat concrete seawalls. However, benefits to biodiversity could be further enhanced by explicitly adopting ecoengineering designs that provide crevices for intertidal organisms. In chapter three, we examined the performance of ecoengineered substrates under the prediction that climate change will enhance rainfall by 20% in the Auckland region. While no effect of increased rainfall was observed for the mobile invertebrate community or the flat plates, increased rainfall did influence the biodiversity of the fouling community on the ridged plates, likely as a consequence of reduced desiccation stress. Although this was only a short-term experiment we predict that given time to develop, a distinct fouling community could influence the diversity mobile invertebrate community, shifting the whole community vertically up the seawall. The review of the Waitematā taxonomy presented in chapter four, provides a reference for future studies of the biodiversity of the Waitematā harbour as well as identifying several gaps in our understanding, a cause for concern. Specifically, we show that non-indigenous species make up a considerable proportion of the fouling species listed for the Harbour and suggest that some of this could have been avoided by the adoption of ecoengineering techniques. Overall, this thesis recognises that habitat heterogeneity, be it natural or man-made, is a vital driver of biodiversity. Each chapter provides additional insight, supporting the benefits of marine ecoengineering. These positive results within the Waitematā Harbour show potential for larger scale experimental trials and for the broader application of these techniques in other locations. By implementing intelligent design and eco-friendly materials in marine infrastructure, we can reduce the impact on local intertidal communities and indirectly reduce the spread of non-indigenous species

    Five years of observations of ozone profiles over Lauder, New Zealand

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    Altitude profiles of ozone (O3) over Lauder (45°S, 170°E) performed using a lidar, ozonesondes, and the satellite-borne Stratospheric Aerosol and Gas Experiment (SAGE II) instrument are presented. These data form one of the few long-term sets of O3 profiles at a Southern Hemisphere location. In the 5 years of data presented, the dominant variation is the annual cycle, the phase and amplitude of which differ below and above 27.5 km. Superposed are irregular episodic variations, caused by various processes. The first process studied is stratosphere-troposphere exchange, characterized by dry and O3-rich air residing in the troposphere, which was found in 21% of the measurements. The second relates to the positioning of the higher polar vortex over Lauder, often in combination with the exchange of air between midlatitude and subtropical stratospheric regions. We present examples of this which were observed over Lauder during the 1997 winter. This winter was selected for further study because of the record-low O3 amounts measured. The third process is mixing of O3-depleted vortex air with midlatitude air after the vortex breakup. We present one example, which shows that a filament originating from the depleted Antarctic vortex significantly lowers O3 amounts over Lauder around 27 November 1997. There is thus a connection between Antarctic O3 depletion and later decrease of O3 amounts at a Southern Hemisphere midlatitude location, namely Lauder

    Explaining the effects of a 1-year intervention promoting physical activity in middle schools: a mediation analysis

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    Objective : The aim of the present study was to examine the mediation effects of changes in psychosocial determinants of physical activity (attitude, social support, self-efficacy, perceived benefits and barriers) on changes in physical activity. Design : One-year intervention study with baseline and 1-year post measures of physical activity habits and psychosocial correlates. Setting : Fifteen middle schools. Subjects : Boys and girls (n = 2840) aged 11–15 years completed the validated questionnaires during class hours. Results : The product-of-coefficients test was used to asses the mediating effects. Self-efficacy for physical activity at school was found to be the only significant mediator of physical activity change. Specifically, self-efficacy for physical activity at school partly mediated the effect of the intervention on total and school-related physical activity change in the intervention group with parental support (P < 0.05). None of the other potential mediators, attitudes, social support, perceived benefits and perceived barriers, seemed to have had a positive effect. Even a suppressor effect was found for attitudes. Given that the effects of self-efficacy and attitudes were of opposite direction, the total mediated/suppressed effects of the intervention were not statistically significant. Conclusions : Positive changes in total and school-related physical activity in adolescents could be partly explained by increases in self-efficacy for physical activity at school through a physical activity intervention in middle schools with parental support. However, the suppressor effect of attitudes decreased this effect. As this is one of the first true mediation analyses in this age group, further research is needed to replicate the importance of these mediators

    Diversity-oriented synthesis as a tool for identifying new modulators of mitosis.

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    The synthesis of diverse three-dimensional libraries has become of paramount importance for obtaining better leads for drug discovery. Such libraries are predicted to fare better than traditional compound collections in phenotypic screens and against difficult targets. Herein we report the diversity-oriented synthesis of a compound library using rhodium carbenoid chemistry to access structurally diverse three-dimensional molecules and show that they access biologically relevant areas of chemical space using cheminformatic analysis. High-content screening of this library for antimitotic activity followed by chemical modification identified 'Dosabulin', which causes mitotic arrest and cancer cell death by apoptosis. Its mechanism of action is determined to be microtubule depolymerization, and the compound is shown to not significantly affect vinblastine binding to tubulin; however, experiments suggest binding to a site vicinal or allosteric to Colchicine. This work validates the combination of diversity-oriented synthesis and phenotypic screening as a strategy for the discovery of biologically relevant chemical entities.This is the author's accepted manuscript. The final version was published in Nature Communications here: http://www.nature.com/ncomms/2014/140117/ncomms4155/full/ncomms4155.html#affil-auth

    Mediating effects of parents’ coping strategies on the relationship between parents’ emotional intelligence and sideline verbal behaviors in youth soccer

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    The overall purpose of this study was to examine the mediating effects of parents’ coping strategies on the relationship between parents’ emotional intelligence and sideline verbal behaviors during their children’s soccer games. Participants were 232 parents (120 mothers and 110 fathers) of youth soccer players age 9–13 years. Observations in situ were carried out at 30 soccer games during a soccer tournament. At the end of the game, parents were approached and asked to complete the Emotional Intelligence Scale and the Brief COPE scale. Structural-equation-modeling analyses revealed that adaptive and maladaptive coping mediated the relationship between regulation of emotion and parents’ praise/encouragement, and negative and derogatory comments during the game. In addition, game result moderated the relationships between emotional intelligence, coping strategies, and parent behaviors. Emotional regulation and adaptive coping may promote desirable parent sideline behaviors and reduce undesirable behaviors

    Large-area 2D selective area growth for photonic crystal surface emitting lasers

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    We report an investigation into large-area selective area growth of InGaAs/GaAs quantum wells by metalorganic vapour phase epitaxy. The emission wavelength tuning range, growth enhancement, and uniformity of material deposited within square masked regions with central square growth windows with widths in the range of 100–300 μm are studied. Micro-photoluminescence measurements at the centre point of each of the growth windows reveals a total wavelength tuning range of 86 nm across all samples, with a typical tuning range of 30 nm for a given window width, dependent upon dielectric mask width. The thickness enhancement in each of features, as determined by white-light interferometric profiling, indicates that centre point growth rate enhancements of between 1.19 and 2.23× are achieved with respect to the nominal epitaxial structure. By comparing the observed emission wavelengths with those simulated using the enhanced quantum well thicknesses, a range of indium concentrations between 12 and 17 % is calculated for the material at the centre of each feature. Two-dimensional analysis of selected features reveals that areas with uniform emission wavelength up to 100 × 100 μm2 in size can be achieved for the mask patterns used, indicating suitability for future applications in the fabrication of monolithically integrated multi-wavelength photonic crystal surface emitting laser arrays

    Small signal modulation of photonic crystal surface emitting lasers

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    We report the small-signal characterization of a PCSEL device, extracting damping factors and modulation efficiencies, and demonstrating -3 dB modulation bandwidths of up to 4.26 GHz. Based on modelling we show that, by reducing the device width and improving the active region design for high-speed modulation, direct modulation frequencies in excess of 50 GHz are achievable

    The Thickness of the Mantle Lithosphere and Collision-Related Volcanism in the Lesser Caucasus

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    The Lesser Caucasus mountains sit on a transition within the Arabia–Eurasia collision zone between very thin lithosphere (<100 km) to the west, under Eastern Anatolia, and a very thick lithospheric root (up to 200 km) in the east, under western Iran. A transect of volcanic highlands running from NW to SE in the Lesser Caucasus allows us to look at the effects of lithosphere thickness variations on the geochemistry of volcanic rocks in this continental collision zone. Volcanic rocks from across the region show a wide compositional range from basanites to rhyolites, and have arc-like geochemical characteristics, typified by ubiquitous negative Nb–Ta anomalies. Magmatic rocks from the SE, where the lithosphere is thought to be thicker, are more enriched in incompatible trace elements, especially the light rare earth elements, Sr and P. They also have more radiogenic ⁸⁷Sr/⁸⁶Sr, and less radiogenic ¹⁴³Nd/¹⁴⁴Nd. Across the region, there is no correlation between SiO₂ content and Sr–Nd isotope ratios, revealing a lack of crustal contamination. Instead, ‘spiky’ mid-ocean ridge basalt normalized trace element patterns are the result of derivation from a subduction-modified mantle source, which probably inherited its subduction component from subduction of the Tethys Ocean prior to the onset of continent–continent collision in the late Miocene. In addition to the more isotopically enriched mantle source, modelling of non-modal batch melting suggests lower degrees of melting and the involvement of garnet as a residual phase in the SE. Melt thermobarometry calculations based on bulk-rock major elements confirm that melting in the SE must occur at greater depths in the mantle. Temperatures of melting below 1200°C, along with the subduction-modified source, suggest that melting occurred within the lithosphere. It is proposed that in the northern Lesser Caucasus this melting occurs close to the base of the very thin lithosphere (at a depth of ∼45 km) as a result of small-scale delamination. A striking similarity between the conditions of melting in NW Iran and the southern Lesser Caucasus (two regions between which the difference in lithosphere thickness is ∼100 km) suggests a common mechanism of melt generation in the mid-lithosphere (∼75 km). The southern Lesser Caucasus magmas result from mixing between partial melts of deep lithosphere (∼120 km in the south) and mid-lithosphere sources to give a composition intermediate between magmas from the northern Lesser Caucasus and NW Iran. The mid-lithosphere magma source has a distinct composition compared with the base of the lithosphere, which is argued to be the result of the increased retention of metasomatic components in phases such as apatite and amphibole, which are stabilized by lower temperatures prior to magma generation

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29
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