564 research outputs found

    Quantifying capture and ingestion of live feeds across three coral species

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    Nutrient acquisition through heterotrophy is critical for the health of reef-building corals. The optimization of exogenous nutrition protocols to support a diversity of aquaculture corals requires improved techniques to assess feeding rates. Here, we compared the feeding rates of three coral species (Acropora millepora, Pocillopora acuta and Galaxea fascicularis) fed Artemia salina through capture rate (indirect) and dissection (direct) approaches, with direct detection and enumeration within dissected polyps facilitated by fluorescent microbeads ingested by the Artemia. When A. millepora was provided Artemia at 3 individuals ml−1 for one hour, the calculated capture rates (0.7 ind. polyp−1 h−1) overestimated prey ingested compared to prey detected directly within polyps (0.2 ind. polyp−1 h−1), and ingestion varied significantly between genotypes. In contrast, for P. acuta, capture rate calculations (1 ind. polyp−1 h−1) underestimated prey detected within polyps (3.5 ind. polyp−1 h−1) and ingestion did not vary between genotypes. For G. fascicularis, the feeding rates were similar as calculated by both capture rates (59 ind. polyp−1 h−1) and by polyp dissections (75 ind. polyp−1 h−1). Results from this study provide valuable insights into coral feeding rates of different coral species that can improve prey enrichment and feeding strategies for nutritional supplementation of corals in captivity

    Biological controls to manage Acropora-eating flatworms in coral aquaculture

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    Coral aquaculture is expanding to supply the marine ornamental trade and active coral reef restoration. A common pest of Acropora corals is the Acropora-eating flatworm Prosthiostomum acroporae, which can cause colonial mortality at high infestation densities on Acropora spp. We investigated the potential of 2 biological control organisms in marine aquaria for the control of P. acroporae infestations. A. millepora fragments infested with adult polyclad flatworms (5 flatworms fragment(-1)) or single egg clusters laid on Acropora skeleton were cohabited with either sixline wrasse Pseudocheilinus hexataenia or the peppermint shrimp Lysmata vittata and compared to a control (i.e. no predator) to assess their ability to consume P. acroporae at different life stages over 24 h. P. hexataenia consumed 100% of adult flatworms from A. millepora fragments (n = 9; 5 flatworms fragment(-1)), while L. vittata consumed 82.0 +/- 26.36% of adult flatworms (mean +/- SD; n= 20). Pseudocheilinus hexataenia did not consume any Prosthiostomum acroporae egg capsules, while L. vittata consumed 63.67 +/- 43.48% (n = 20) of egg capsules on the Acropora skeletons. Mean handling losses in controls were 5.83% (shrimp system) and 3.50% (fish system) of flatworms and 2.39% (fish system) and 3.50% (shrimp system) of egg capsules. Encounters between L. vittata and P. hexataenia result in predation of P. acroporae on an Acropora coral host and represent viable biological controls for reducing infestations of P. acroporae in aquaculture systems

    Diel CO2 cycles reduce severity of bahavioural abnormalities in coral reef fish under ocean acidification

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    Elevated CO2 levels associated with ocean acidification (OA) have been shown to alter behavioural responses in coral reef fishes. However, all studies to date have used stable pCO2 treatments, not considering the substantial diel pCO2 variation that occurs in shallow reef habitats. Here, we reared juvenile damselfish, Acanthochromis polyacanthus, and clownfish, Amphiprion percula, at stable and diel cycling pCO2 treatments in two experiments. As expected, absolute lateralization of A. polyacanthus and response to predator cue of Am. percula were negatively affected in fish reared at stable, elevated pCO2 in both experiments. However, diel pCO2 fluctuations reduced the negative effects of OA on behaviour. Importantly, in experiment two, behavioural abnormalities that were present in fish reared at stable 750 μatm CO2 were largely absent in fish reared at 750 ± 300 μatm CO2. Overall, we show that diel pCO2 cycles can substantially reduce the severity of behavioural abnormalities caused by elevated CO2. Thus, past studies may have over-estimated the impacts of OA on the behavioural performance of coral reef fishes. Furthermore, our results suggest that diel pCO2 cycles will delay the onset of behavioural abnormalities in natural populations

    The life cycle of the Acropora coral-eating flatworm (AEFW), Prosthiostomum acroporae; the influence of temperature and management guidelines

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Barton, J. A., Hutson, K. S., Bourne, D. G., Humphrey, C., Dybala, C., & Rawlinson, K. A. The life cycle of the Acropora coral-eating flatworm (AEFW), Prosthiostomum acroporae; the influence of temperature and management guidelines. Frontiers in Marine Science, 6, (2019): 524, doi: 10.3389/fmars.2019.00524.As coral aquaculture is increasing around the world for reef restoration and trade, mitigating the impact of coral predators, pathogens and parasites is necessary for optimal growth. The Acropora coral-eating flatworm (AEFW), Prosthiostomum acroporae (Platyhelminthes: Polycladida: Prosthiostomidae) feeds on wild and cultivated Acropora species and its inadvertent introduction into reef tanks can lead to the rapid death of coral colonies. To guide the treatment of infested corals we investigated the flatworm’s life cycle parameters at a range of temperatures that represent those found in reef tanks, coral aquaculture facilities and seasonal fluctuations in the wild. We utilized P. acroporae from a long-term in vivo culture on Acropora species to examine the effects of temperature (3°C increments from 21 to 30°C) on flatworm embryonation period, hatching success, hatchling longevity, and time to sexual maturity. Our findings show that warmer seawater shortened generation times; at 27°C it took, on average, 11 days for eggs to hatch, and 35 days for flatworms to reach sexual maturity, giving a minimum generation time of 38 days, whereas at 24°C the generation time was 64 days. Warmer seawater (24–30°C) also increased egg hatching success compared to cooler conditions (21°C). These results indicate that warmer temperatures lead to higher population densities of P. acroporae. Temperature significantly increased the growth rate of P. acroporae, with individuals reaching a larger size at sexual maturity in warmer temperatures, but it did not influence hatchling longevity. Hatchlings, which can swim as well as crawl, can survive between 0.25 and 9 days in the absence of Acropora, and could therefore disperse between coral colonies and inter-connected aquaria. We used our data to predict embryonation duration and time to sexual maturity at 21–30°C, and discuss how to optimize current treatments to disrupt the flatworm’s life cycle in captivity.This study was funded by a James Cook University Development Grant, “Parasite cultivation techniques: in vitro and in vivo culture methods for ecological and applied aquatic parasitology research” awarded to KH. Additional funding to KR and CD was raised through crowdfunding on Experiment.com (https://doi.org/10.18258/1621) and a donation from the Atlanta Reef Club, Duluth, GA, United States

    Achieving UNAIDS 90-90-90 targets for pregnant and postpartum women in sub-Saharan Africa: progress, gaps and research needs

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    The implementation of the 2013 World Health Organization Option B+ recommendations for HIV treatment during pregnancy has helped drive significant progress in achieving universal treatment for pregnant and postpartum women in sub-Saharan Africa (SSA). Yet, critical research and implementation gaps exist in achieving the UNAIDS 90-90-90 targets. To help guide researchers, programmers and policymakers in prioritising these areas, we undertook a comprehensive review of the progress, gaps and research needs to achieve the 90-90-90 targets for this population in the Option B+ era, including early infant HIV diagnosis (EID) for HIV-exposed infants. Salient areas where progress has been achieved or where gaps remain include: (1) knowledge of HIV status is higher among people with HIV in southern and eastern Africa compared to western and central Africa (81% versus 48%, UNAIDS); (2) access to antiretroviral therapy (ART) for pregnant women has doubled in 22 of 42 SSA countries, but only six have achieved the second 90, and nearly a quarter of pregnant women initiating ART become lost to follow-up; (3) viral suppression data for this population are sparse (estimates range from 30% to 98% peripartum), with only half of women maintaining suppression through 12 months postpartum; and (4) EID rates range from 15% to 62%, with only three of 21 high-burden SSA countries testing >50% HIV-exposed infants within the first 2 months of life. We have identified and outlined promising innovations and research designed to address these gaps and improve the health of pregnant and postpartum women living with HIV and their infants

    Distinguishing Dark Matter Annihilation Enhancement Scenarios via Halo Shapes

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    Sommerfeld enhancement and Breit-Wigner enhancement of the dark matter annihilation have been proposed to explain the "boost factor" which is suggested by observed cosmic ray excesses. Although these two scenarios can provide almost indistinguishable effects on the cosmic ray fluxes, the cross sections of the self-interaction in those enhancement mechanisms are drastically different. As a result, we show that they can be distinguished by examining the effects of the self-interaction on the halo shapes. In Sommerfeld enhancement models with m_phi<100MeV and m_DM<3TeV, the self-interaction can leave observable imprints in the galactic dynamics, while dark matter is effectively collisionless in Breit-Wigner models.Comment: 4 pages, 1 figur

    Extensive mass spectrometry-based analysis of the fission yeast proteome: the Schizosaccharomyces pombe PeptideAtlas

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    We report a high quality and system-wide proteome catalogue covering 71% (3,542 proteins) of the predicted genes of fission yeast, Schizosaccharomyces pombe, presenting the largest protein dataset to date for this important model organism. We obtained this high proteome and peptide (11.4 peptides/protein) coverage by a combination of extensive sample fractionation, high resolution Orbitrap mass spectrometry, and combined database searching using the iProphet software as part of the Trans-Proteomics Pipeline. All raw and processed data are made accessible in the S. pombe PeptideAtlas. The identified proteins showed no biases in functional properties and allowed global estimation of protein abundances. The high coverage of the PeptideAtlas allowed correlation with transcriptomic data in a system-wide manner indicating that post-transcriptional processes control the levels of at least half of all identified proteins. Interestingly, the correlation was not equally tight for all functional categories ranging from r(s) >0.80 for proteins involved in translation to r(s) <0.45 for signal transduction proteins. Moreover, many proteins involved in DNA damage repair could not be detected in the PeptideAtlas despite their high mRNA levels, strengthening the translation-on-demand hypothesis for members of this protein class. In summary, the extensive and publicly available S. pombe PeptideAtlas together with the generated proteotypic peptide spectral library will be a useful resource for future targeted, in-depth, and quantitative proteomic studies on this microorganism

    The Effects of Serotonin Receptor Antagonists on Contraction and Relaxation Responses Induced by Electrical Stimulation in the Rat Small Intestine

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    Background: The main source of 5-HT in body is in enterchromafin cells of intestine, different studies mentioned different roles for endogenous 5-HT and receptors involved and it is not clearified the mechanism of action of endogenous 5-HT. Objectives: To study the role of endogenous 5-HT on modulation of contraction and relaxation responses induced by electrical field stimulation (EFS) in different regions of the rat intestine. Materials and Methods: Segments taken from the rat duodenum, jejunum, mid and terminal ileum were vertically mounted, connected to a transducer and exposed to EFS with different frequencies in the absence and presence of various inhibitors of enteric mediators i. e. specific 5-HT receptor antagonists. Results: EFS-induced responses were sensitive to TTX and partly to atropine, indicating a major neuronal involvement and a cholinergic system. Pre-treatment with WAY100635 (a 5-HT1A receptor antagonist) and granisetron up to 10.0 µM, GR113808 (a 5-HT4 receptor antagonist), methysergide and ritanserin up to 1.0 µM, failed to modify responses to EFS inall examined tissues. In the presence of SB258585 1.0 µM (a 5-HT6 receptor antagonist) there was a trend to enhance contraction in the proximal part of the intestine and reduce contraction in the distal part. Pre-treatment with SB269970A 1.0 µM (5-HT7 receptor antagonist) induced a greater contractile response to EFS at 0.4 Hz only in the duodenum. Conclusions: The application of 5-HT1A, 5-HT2, 5-HT3, 5-HT4, 5-HT6 and 5-HT7 receptor antagonists, applied at concentrations lower than 1.0 µM did not modify the EFS-induced contraction and relaxation responses, whichsuggests the unlikely involvement of endogenous 5-HT in mediating responses to EFS in the described test conditions. Keywords: Electric Stimulation Therapy; Serotonin 5-HT1 Receptor Antagonists; Intestine, Smal

    Managing Urology Consultations During COVID-19 Pandemic: Application of a Structured Care Pathway

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    OBJECTIVE: To describe and evaluate a risk-stratified triage pathway for inpatient urology consultations during the SARS-CoV-2 (COVID-19) pandemic. This pathway seeks to outline a urology patient care strategy that reduces the transmission risk to both healthcare providers and patients, reduces the healthcare burden, and maintains appropriate patient care. MATERIALS AND METHODS: Consultations to the urology service during a 3-week period (March 16 to April 2, 2020) were triaged and managed via one of 3 pathways: Standard, Telemedicine, or High-Risk. Standard consults were in-person consults with non COVID-19 patients, High-Risk consults were in-person consults with COVID-19 positive/suspected patients, and Telemedicine consults were telephonic consults for low-acuity urologic issues in either group of patients. Patient demographics, consultation parameters and consultation outcomes were compared to consultations from the month of March 2019. Categorical variables were compared using Chi-square test and continuous variables using Mann-Whitney U test. A P value \u3c.05 was considered significant. RESULTS: Between March 16 and April 2, 2020, 53 inpatient consultations were performed. By following our triage pathway, a total of 19/53 consultations (35.8%) were performed via Telemedicine with no in-person exposure, 10/53 consultations (18.9%) were High-Risk, in which we strictly controlled the urology team member in-person contact, and the remainder, 24/53 consultations (45.2%), were performed as Standard in-person encounters. COVID-19 associated consultations represented 18/53 (34.0%) of all consultations during this period, and of these, 8/18 (44.4%) were managed successfully via Telemedicine alone. No team member developed COVID-19 infection. CONCLUSION: During the COVID-19 pandemic, most urology consultations can be managed in a patient and physician safety-conscious manner, by implementing a novel triage pathway
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