216 research outputs found

    Assessment of the barramundi (Lates calcarifer) fishery in the Southern Gulf of Carpentaria, Queensland, Australia.

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    Wild-capture barramundi (Lates calcarifer) forms the basis of important commercial, recreational and customary Indigenous fisheries in Queensland, with an estimated harvest of about 700 tonnes in 2015 (Saunders et al. 2016). For stock status assessment, barramundi in Queensland are considered to consist of seven genetically distinct populations. Within the Gulf of Carpentaria (GoC), there are two genetic stocks split at around 13⁰ S - a Northern Gulf of Carpentaria stock and a Southern Gulf of Carpentaria stock. The Gulf of Carpentaria Inshore Fin Fish Fishery harvests barramundi from both these stocks, but the current assessment focuses on the Southern Gulf of Carpentaria (Southern GoC) barramundi stock, which produces, on average, greater than 50% of the annual commercial harvest of barramundi in Queensland and was listed as transitional-depleting in the 2016 Status of Australian Fish Stocks report (Saunders et al. 2016)

    Perspectives of UK adolescents on the youth climate strikes

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    The aromatase inhibitor letrozole enhances the effect of doxorubicin and docetaxel in an MCF7 cell line model

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    Introduction: Post-menopausal women with estrogen receptor (ER) positive breast cancer receive adjuvant chemotherapy and endocrine therapy sequentially since tamoxifen may antagonise the cytotoxicity of chemotherapy drugs. With increased use of aromatase inhibitors (AIs) in place of tamoxifen, the potential use of concomitant chemo-endocrine treatments with the AI letrozole, before clinical trials are undertaken, requires evaluation. Methods: MCF7-aro cells expressing the aromatase gene were treated with letrozole, doxorubicin and docetaxel. The effects of different drug concentrations, drug combinations and scheduling on cytotoxicity and aromatase activity were investigated. Key receptor, cell cycle regulation and apoptosis proteins were examined by immunoblotting. Results: Administration of letrozole with either doxorubicin or docetaxel resulted in increased levels of cytotoxicity under all treatment schedules (add in, sequential or simultaneous drug administration) with the greatest anti-proliferative effect observed using concomitant treatment (letrozole first with chemotherapy added in). The inhibitory effect of letrozole on aromatase activity was unchanged by the addition of doxorubicin or docetaxel. Letrozole treatment resulted in decreased HER2 expression and addition of doxorubicin and docetaxel to letrozole led to elevated ER-ß levels. Conclusions: In vitro, letrozole, unlike tamoxifen, enhances the cytotoxicity of both doxorubicin and docetaxel. This supports the prospect of trials using letrozole with chemotherapy in postmenopausal women with ER positive breast cancer

    Towards an Initial Quota for the Queensland Mud Crab Fishery

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    Mud crabs in Queensland (principally Scylla serrata) are captured by baited pots. They are found mostly in estuaries and adjacent foreshores. Their populations are spatially variable and separated between the east coast and the Gulf of Carpentaria. No previous stock assessment has evaluated the sustainability of mud crab harvests in Queensland. This stock assessment is new, using the modified catch-MSY method of Haddon et al. (2018) from Martell and Froese (2013). The model used data from 1988/89 to 2017/18. This comprised of annual commercial harvests, and an estimate of recreational harvest derived from state-wide phone-diary surveys. The assessment provides estimates of exploitable biomass in 2017-18 and recommends Total Allowable Catches for the east coast and Gulf of Carpentaria stocks. The recommendations considered the biological sustainability of the stocks. Other objectives, such as social and economic, were not addressed in the analysis. However, they are important considerations when setting limits on harvests

    Intrarenal Mas and AT(1) receptors play a role in mediating the excretory actions of renal interstitial angiotensin-(1-7) infusion in anaesthetized rats

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    New Findings What is the central question of this study? Dietary sodium manipulation alters the magnitude of angiotensin‐(1–7) [Ang‐(1–7)]‐induced natriuresis. The present study sought to determine whether this was related to relative changes in the activity of intrarenal Mas and/or AT1 receptors. What is the main finding and its importance? Angiotensin‐(1–7)‐induced diuresis and natriuresis is mediated by intrarenal Mas receptors. However, intrarenal AT1 receptor blockade also had an inhibitory effect on Ang‐(1–7)‐induced natriuresis and diuresis. Thus, Ang‐(1–7)‐induced increases in sodium and water excretion are dependent upon functional Mas and AT1 receptors. We investigated whether angiotensin‐(1–7) [Ang‐(1–7)]‐induced renal haemodynamic and excretory actions were solely dependent upon intrarenal Mas receptor activation or required functional angiotensin II type 1 (AT1) receptors. The renin–angiotensin system was enhanced in anaesthetized rats by prior manipulation of dietary sodium intake. Angiotensin‐(1–7) and AT1 and Mas receptor antagonists were infused into the kidney at the corticomedullary border. Mas receptor expression was measured in the kidney. Mean arterial pressure, urine flow and fractional sodium excretion were 93 ± 4 mmHg, 46.1 ± 15.7 Όl min−1 kg−1 and 1.4 ± 0.3%, respectively, in the normal‐sodium group and 91 ± 2 mmHg, 19.1 ± 3.3 Όl min−1 kg−1 and 0.7 ± 0.2%, respectively, in the low‐sodium group. Angiotensin‐(1–7) infusion had no effect on mean arterial pressure in rats receiving a normal‐sodium diet but decreased it by 4 ± 5% in rats receiving a low‐sodium diet (P < 0.05). Interstitial Ang‐(1–7) infusion increased urine flow twofold and fractional sodium excretion threefold (P < 0.05) in rats receiving a normal‐sodium diet and to a greater extent, approximately three‐ and fourfold, respectively, in rats receiving the low‐sodium diet (both P < 0.05). Angiotensin‐(1–7)‐induced increases in urine flow and fractional sodium excretion were absent in both dietary groups during intrarenal AT1 or Mas receptor inhibition after either losartan or A‐779, respectively. Thus, AT1 receptor activation, as well as Mas receptor activation, plays an essential role in mediating Ang‐(1–7)‐induced natriuresis and diuresis. Whether this is because Ang‐(1–7) partly antagonizes AT1 receptors or whether Ang‐(1–7)‐induced natriuresis is mediated through AT1–Mas receptor dimerization remains unclear

    Quantitative assessment of the Queensland saucer scallop (Amusium balloti) fishery

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    In recent years (2015 and 2016) there has been growing concern from members of the fishing industry and the Queensland Government over declining catches of legal-sized saucer scallop. This led to a request in mid-2016 by Fisheries Queensland, the fisheries management service within the Department of Agriculture and Fisheries, for an investigative analysis of the status of saucer scallops. The scope of the investigation was limited to a short time frame of three months to urgently analyse the most recent data and undertake a stock assessment. This report provides findings that support the concerns about low abundance of legal-sized scallops. Average catch rates from January 2015 to April 2016 were the lowest in the 39-year record. These recent average catch rates are slightly lower than those in 1996 when the scallop population size fell to low levels and emergency closed areas were implemented by the Government. From these data the model estimates of spawning stock in 2015 are potentially as low as 5-6% of 1977 levels, when the fishery was in its early development

    A SEP Mission to Jupiter Using the Stretched Lens Array

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    As space exploration continues to be a primary focus of NASA, solar electric propulsion (SEP) becomes a forerunner in the mode of transportation to reach other planets in our solar system. Several critical issues emerge as potential barriers to this approach such as reducing solar array radiation damage, operating the array at high voltage (>300 V) for extended times for Hall or ion thrusters, and designing an array that will be resistant to micrometeoroid impacts and the differing environmental conditions as the vehicle travels further into space. It is also of great importance to produce an array that is light weight to preserve payload mass fraction and to do this at a cost that is lower than today's arrays. This paper will describe progress on an array that meets all these requirements and will detail its use in a solar electric mission to Jupiter. From 1998-2001, NASA flew the Deep Space 1 mission that validated the use of ion propulsion for extended space missions. This highly successful two-year mission also used a novel SCARLET solar array that concentrated sunlight eight-fold onto small area solar cells. This array performed flawlessly and within 2% of its projected performance over the entire mission. That design has evolved into the Stretched Lens Array (SLA) shown in figure 1. The primary difference between SCARLET and the SLA is that no additional glass cover is used over the silicone lens. This has led to significant mass, cost and complexity reductions. The module shown in figure 1 is the latest version of the design. This design leads to a specific power exceeding 300 W/kg at voltages exceeding 300 V. In addition, this module has been tested to voltages over 1000 V while under hypervelocity particle impact in a plasma environment with no arcing. Furthermore array segments are under test for corona breakdown that can become a critical issue for long term, high voltage missions

    Transiently expressed CRISPR/Cas9 induces wild-type dystrophin in vitro in DMD patient myoblasts carrying duplications

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    Among the mutations arising in the DMD gene and causing Duchenne Muscular Dystrophy (DMD), 10-15% are multi-exon duplications. There are no current therapeutic approaches with the ability to excise large multi-exon duplications, leaving this patient cohort without mutation-specific treatment. Using CRISPR/Cas9 could provide a valid alternative to achieve targeted excision of genomic duplications of any size. Here we show that the expression of a single CRISPR/Cas9 nuclease targeting a genomic region within a DMD duplication can restore the production of wild-type dystrophin in vitro. We assessed the extent of dystrophin repair following both constitutive and transient nuclease expression by either transducing DMD patient-derived myoblasts with integrating lentiviral vectors or electroporating them with CRISPR/Cas9 expressing plasmids. Comparing genomic, transcript and protein data, we observed that both continuous and transient nuclease expression resulted in approximately 50% dystrophin protein restoration in treated myoblasts. Our data demonstrate that a high transient expression profile of Cas9 circumvents its requirement of continuous expression within the cell for targeting DMD duplications. This proof-of-concept study therefore helps progress towards a clinically relevant gene editing strategy for in vivo dystrophin restoration, by highlighting important considerations for optimizing future therapeutic approaches
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