227 research outputs found

    Age estimation of barramundi (Lates calcarifer) over multiple seasons from the southern Gulf of Carpentaria using FT-NIR spectroscopy

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    The age of whole otoliths from barramundi (Lates calcarifer) obtained from the southern Gulf of Carpentaria were estimated using Fourier transform near-infrared (FT-NIR) spectroscopy. Otoliths from 1716 barramundi collected in 2006, 2009 and 2012–2015 were used in this study. Partial least-squares regression models (PLS-R) and multiple linear regression models (MLR) were developed from the diffuse reflectance spectra and the age was obtained from traditional sectioned otoliths. Calibration models were built up over consecutive years (2012–2015) by using a subset of the samples and used to predict the age of the remaining samples and samples from the following year. Results suggest that when seasonal (temporal) variability is incorporated into the calibration model, FT-NIR has the ability to predict barramundi age (validation R2 ranged from 0.73 to 0.78; RMSEP ranged from 6.92 to 7.64 months). The predicted age class was within 1 year of the reference age in over 96% of the samples. These models were also able to predict the age of otoliths from 2006 and 2009, which were retrieved from long-term storage (validation R2 ranged from 0.77 to 0.84; RMSEP ranged from 8.66 to 10.88 months). The results from this study have shown the potential for barramundi from the southern Gulf of Carpentaria to be aged quickly and accurately by using FT-NIR

    Joint PDF modelling of turbulent flow and dispersion in an urban street canyon

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    The joint probability density function (PDF) of turbulent velocity and concentration of a passive scalar in an urban street canyon is computed using a newly developed particle-in-cell Monte Carlo method. Compared to moment closures, the PDF methodology provides the full one-point one-time PDF of the underlying fields containing all higher moments and correlations. The small-scale mixing of the scalar released from a concentrated source at the street level is modelled by the interaction by exchange with the conditional mean (IECM) model, with a micro-mixing time scale designed for geometrically complex settings. The boundary layer along no-slip walls (building sides and tops) is fully resolved using an elliptic relaxation technique, which captures the high anisotropy and inhomogeneity of the Reynolds stress tensor in these regions. A less computationally intensive technique based on wall functions to represent boundary layers and its effect on the solution are also explored. The calculated statistics are compared to experimental data and large-eddy simulation. The present work can be considered as the first example of computation of the full joint PDF of velocity and a transported passive scalar in an urban setting. The methodology proves successful in providing high level statistical information on the turbulence and pollutant concentration fields in complex urban scenarios.Comment: Accepted in Boundary-Layer Meteorology, Feb. 19, 200

    Imatinib in combination with hydroxyurea versus hydroxyurea alone as oral therapy in patients with progressive pretreated glioblastoma resistant to standard dose temozolomide

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    A randomized, multicenter, open-label, phase 3 study of patients with progressive, recurrent glioblastoma multiforme (GBM) for whom front-line therapy had failed was conducted. This study was designed to determine whether combination therapy with imatinib and hydroxyurea (HU) has superior antitumor activity compared with HU monotherapy in the treatment of recurrent GBM. The target population consisted of patients with confirmed recurrent GBM and an Eastern Cooperative Oncology Group performance status of 0-2 who had completed previous treatment comprising surgical resection, irradiation therapy, and first-line chemotherapy (preferably temozolomide (TMZ) containing regimen) and who have progressed despite treatment. If first-line chemotherapy did not contain TMZ, a second completed chemotherapy was acceptable. The primary efficacy parameter was progression-free survival (PFS). The primary comparison of combination therapy versus monotherapy for PFS was not significant (adjusted P = 0.56). The hazard ratio (HR) (adjusted HR = 0.93) was not clinically relevant. The median PFS for the combination arm was low at 6 weeks and similar to the median PFS in the monotherapy arm (6 weeks). The 6-month PFS for the two treatment groups was very similar (5% in the combination arm vs. 7% in the monotherapy arm). No clinically meaningful differences were found between the two treatment arms, and the primary study end point was not met. Among the patients receiving imatinib, no adverse events were reported that were either previously unknown or unexpected as a consequence of the disease

    Mining deep-ocean mineral deposits: what are the ecological risks?

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    A key question for the future management of the oceans is whether the mineral deposits that exist on the seafloor of the deep ocean can be extracted without significant adverse effects to the environment. The potential impacts of mining are wide-ranging and will vary depending on the type of metal-rich mineral deposit being mined. There is, currently, a significant lack of information about deep-ocean ecosystems and about potential mining technologies: thus, there could be many unforeseen impacts. Here, we discuss the potential ecological impacts of deep-ocean mining and identify the key knowledge gaps to be addressed. Baseline studies must be undertaken, as well as regular monitoring of a mine area, before, during, and after mineral extraction.The attached document is the author’s submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it

    National strategy for palliative care of severely ill and dying people and their relatives in pandemics (PallPan) in Germany - study protocol of a mixed-methods project

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    BACKGROUND In the SARS-CoV-2 pandemic, general and specialist Palliative Care (PC) plays an essential role in health care, contributing to symptom control, psycho-social support, and providing support in complex decision making. Numbers of COVID-19 related deaths have recently increased demanding more palliative care input. Also, the pandemic impacts on palliative care for non-COVID-19 patients. Strategies on the care for seriously ill and dying people in pandemic times are lacking. Therefore, the program 'Palliative care in Pandemics' (PallPan) aims to develop and consent a national pandemic plan for the care of seriously ill and dying adults and their informal carers in pandemics including (a) guidance for generalist and specialist palliative care of patients with and without SARS-CoV-2 infections on the micro, meso and macro level, (b) collection and development of information material for an online platform, and (c) identification of variables and research questions on palliative care in pandemics for the national pandemic cohort network (NAPKON). METHODS Mixed-methods project including ten work packages conducting (online) surveys and qualitative interviews to explore and describe i) experiences and burden of patients (with/without SARS-CoV-2 infection) and their relatives, ii) experiences, challenges and potential solutions of health care professionals, stakeholders and decision makers during the SARS-CoV-2 pandemic. The work package results inform the development of a consensus-based guidance. In addition, best practice examples and relevant literature will be collected and variables for data collection identified. DISCUSSION For a future \textquotedblpandemic preparedness\textquotedbl national and international recommendations and concepts for the~care of severely ill and dying people are necessary considering both generalist and specialist palliative care in the home care and inpatient setting

    Combining fish and benthic communities into multiple regimes reveals complex reef dynamics

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    Abstract Coral reefs worldwide face an uncertain future with many reefs reported to transition from being dominated by corals to macroalgae. However, given the complexity and diversity of the ecosystem, research on how regimes vary spatially and temporally is needed. Reef regimes are most often characterised by their benthic components; however, complex dynamics are associated with losses and gains in both fish and benthic assemblages. To capture this complexity, we synthesised 3,345 surveys from Hawai‘i to define reef regimes in terms of both fish and benthic assemblages. Model-based clustering revealed five distinct regimes that varied ecologically, and were spatially heterogeneous by island, depth and exposure. We identified a regime characteristic of a degraded state with low coral cover and fish biomass, one that had low coral but high fish biomass, as well as three other regimes that varied significantly in their ecology but were previously considered a single coral dominated regime. Analyses of time series data reflected complex system dynamics, with multiple transitions among regimes that were a function of both local and global stressors. Coupling fish and benthic communities into reef regimes to capture complex dynamics holds promise for monitoring reef change and guiding ecosystem-based management of coral reefs

    O3oxidation of SO2in sea-salt aerosol water: Size distribution of non-sea-salt sulfate during the First Aerosol Characterization Experiment (ACE 1)

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    Non sea-salt sulfate (NSS) of 2.2-2.3 nmol m(-3) total magnitude in aerosols observed during the First Aerosol Characterization Experiment (ACE-1) at Cape Grim, Tasmania, was trimodally distributed with similar to 1 nmol NSS m(-3) in > 0.7 mu m ambient diameter (diam) coarse seasalt mode aerosols; despite this low NSS concentration, [H2SO4(g)] was so low that 0.7 mu m diam aerosols. The mechanism of O-3 oxidation of SO2 in sea-salt aerosol water (SSAW) is assessed for its capability to explain this coarse aerosol NSS. Limitation of this mechanism's NSS contribution is largely due to SSAW's buffering capacity since its reaction rate is reduced by 2 orders of magnitude at pH 6 versus the pH greater than or equal to 8 of unreacted SSAW. However, the buffering capacity of sea-salt aerosols may have been significantly enhanced over that of bulk seawater alkalinity. This appears to be due to carbonate resulting from small fragments of biogenic CaCO3 in the ocean's surface microlayer. Given the observed nonsoil calcium excess over that in bulk seawater, the estimated actual buffering capacity of sea-salt aerosols observed during ACE 1 was 50%, or more, enhanced over that due to bulk seawater alkalinity. Considering this enhanced buffering capacity, O-3 oxidation of SO2 in SSAW can produce sufficient NSS to explain 70-90% of the similar to 1 nmol m(-3) found in > 0.7 mu m diam coarse sea-salt aerosols with cloud processing and further oxidation of SO2 in SSAW (i.e., pH < 6) by other sea-salt conversion mechanisms contributing the remainder. The amount of NSS produced by sea-salt conversion mechanisms during the ACE 1 remote Southern Ocean experiment vied with homogeneous and cloud processing in their contribution to the total observed NSS of 2.2-2.3 nmol m(-3)
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