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Reef coral survival and mortality at low temperatures in the Arabian Gulf: new species-specific lower temperature limits 总被引:8,自引:0,他引:8
A series of cold fronts passing over the western Arabian Gulf from December 1988 to March 1989 produced the longest period of sustained low water temperatures ever recorded in a coral reef area. Sea water temperatures recorded on two reefs during this period provide new estimates of lower thermal limits for reef coral survival. Severe mortality of the corals Acropora pharaonis and Platygyra daedalea occurred at the northern site where minimum temperatures fell below 11.5°C on four consecutive days and mean daily temperatures were 13°C or less for more than 30 days. However, Porites compressa, the principal reef-former in this area, and various faviid corals initially showed only sub-lethal effects and appeared normal after six months. Corals were not damaged at the southern site, where minimum water temperature fell below 12.5°C for two consecutive days, but mean temperatures were 14°C or less for only 5 non-consecutive days. 相似文献
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Steve Harakeh Esam Azhar Saad Almasaudi Kohar Berge Kissoyan Sukayna Fadlallah Arax Tanelian Ghassan M. Matar 《Saudi Journal of Biological Sciences》2019,26(7):1576-1580
Background and aimExtended-spectrum beta-lactamases are the main cause of resistance in Enterobacteriaceae to beta lactam antibiotics. The aim of this study was to evaluate the antimicrobial effect of EpiQuercican supplement, combined with different antimicrobial agents, on ESBL-producing isolates and determine the underlying molecular mechanism of resistance in these isolates.Materials and methodsEleven ESBL producing Enterobacteriaceae isolates were collected from Saudi Arabia hospitals between 2016 and 2017 and disk diffusion test was performed in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines to determine the susceptibility of the isolates to 5 different antibiotics in the presence of EpiQuercican supplement. Polymerase chain reaction was performed for detection of ESBL genes, and efflux pump inhibitor was used to study the mechanism of resistance in these isolates.ResultsThe best synergistic effect was obtained when the supplement was combined with carbapenems followed by 4th generation cephalosporins. Either no effect or antagonistic effect was seen with most of the isolates when the supplement was added to the 3rd generation of cephalosporins. Among the tested genes responsible for ESBL production in this study, our results indicated the predominance of TEM genes (73%) followed by CTX-M genes (9%). As for the mechanism of resistance in ESBL isolates, 4 isolates showed to use efflux pumps as their main mechanism of resistance.ConclusionThe EpiQuercican supplement showed some promising results, yet its antibacterial mechanism of action needs to be elucidated further. 相似文献
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Yusef H. Fadlallah 《Coral reefs (Online)》1983,2(3):129-150
This paper brings together widely scattered information on sexual reproduction in scleractinian corals. It includes a review of information and ideas on sex determination, gametogenesis, gametogenic cycles, fertilization and embryonic development, spawning and planula release, larval behavior, settlement and metamorphosis. The review deals with corals from different habitats and organismic assemblages, including tropical reef corals, temperate water corals, solitary and colonial forms. A summary table of coral species and their known reproductive characteristics is presented. 相似文献
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El-Baba Chirine Baassiri Amro Kiriako Georges Dia Batoul Fadlallah Sukayna Moodad Sara Darwiche Nadine 《Apoptosis : an international journal on programmed cell death》2021,26(9-10):491-511
Apoptosis - Terpenoids are the largest class of natural products, most of which are derived from plants. Amongst their numerous biological properties, their anti-tumor effects are of interest for... 相似文献
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Florian Plaza Onate Jean-Michel Batto Catherine Juste Jehane Fadlallah Cyrielle Fougeroux Doriane Gouas Nicolas Pons Sean Kennedy Florence Levenez Joel Dore S Dusko Ehrlich Guy Gorochov Martin Larsen 《BMC genomics》2015,16(1)
Background
The biological and clinical consequences of the tight interactions between host and microbiota are rapidly being unraveled by next generation sequencing technologies and sophisticated bioinformatics, also referred to as microbiota metagenomics. The recent success of metagenomics has created a demand to rapidly apply the technology to large case–control cohort studies and to studies of microbiota from various habitats, including habitats relatively poor in microbes. It is therefore of foremost importance to enable a robust and rapid quality assessment of metagenomic data from samples that challenge present technological limits (sample numbers and size). Here we demonstrate that the distribution of overlapping k-mers of metagenome sequence data predicts sequence quality as defined by gene distribution and efficiency of sequence mapping to a reference gene catalogue.Results
We used serial dilutions of gut microbiota metagenomic datasets to generate well-defined high to low quality metagenomes. We also analyzed a collection of 52 microbiota-derived metagenomes. We demonstrate that k-mer distributions of metagenomic sequence data identify sequence contaminations, such as sequences derived from “empty” ligation products. Of note, k-mer distributions were also able to predict the frequency of sequences mapping to a reference gene catalogue not only for the well-defined serial dilution datasets, but also for 52 human gut microbiota derived metagenomic datasets.Conclusions
We propose that k-mer analysis of raw metagenome sequence reads should be implemented as a first quality assessment prior to more extensive bioinformatics analysis, such as sequence filtering and gene mapping. With the rising demand for metagenomic analysis of microbiota it is crucial to provide tools for rapid and efficient decision making. This will eventually lead to a faster turn-around time, improved analytical quality including sample quality metrics and a significant cost reduction. Finally, improved quality assessment will have a major impact on the robustness of biological and clinical conclusions drawn from metagenomic studies.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1406-7) contains supplementary material, which is available to authorized users. 相似文献6.
Alexis Mathian Romain Jouenne Driss Chader Fleur Cohen-Aubart Julien Haroche Jehane Fadlallah Laetitia Cla?r Lucile Musset Guy Gorochov Zahir Amoura Makoto Miyara 《PloS one》2015,10(12)
Background/Purpose
A slight increase in the proportion of circulating regulatory T (Treg) cells has been reported in systemic lupus erythematosus (SLE) patients taking oral prednisone. The effects of intravenous (IV) high dose methylprednisolone (MP) on Tregs have not yet been described, especially in active SLE.Methods
We prospectively analyzed the proportion of circulating CD4+ Treg cell subsets defined as follows: (1) naïve Treg (nTreg) FoxP3lowCD45RA+ cells; (2) effector Treg (eTreg) FoxP3highCD45RA− cells; and (3) non-suppressive FoxP3lowCD45RA− cells (non-regulatory Foxp3low T cells). Peripheral blood mononuclear cells of patients with active SLE were analyzed before the first infusion of IV high dose MP (day 0) and the following days (day 1, day 2, ±day 3 and ±day 8). The activity of SLE was assessed by the SLEDAI score.Results
Seventeen patients were included. Following MP infusions, the median (range) percentage of eTregs significantly increased from 1.62% (0.53–8.43) at day 0 to 2.80% (0.83–14.60) at day 1 (p = 0.003 versus day 0), 4.64% (0.50–12.40) at day 2 (p = 0.06 versus day 1) and 7.50% (1.02–20.70) at day 3 (p = 0.008 versus day 2), and declined to baseline values at day 8. Expanding eTreg cells were actively proliferating, as they expressed Ki-67. The frequency of non-regulatory FoxP3low T cells decreased from 6.39% (3.20–17.70) at day 0 to 4.74% (1.03–9.72) at day 2 (p = 0.005); nTreg frequency did not change. All patients clinically improved immediately after MP pulses. The absence of flare after one year of follow up was associated with a higher frequency of eTregs at day 2.Conclusion
IV high dose MP induces a rapid, dramatic and transient increase in circulating regulatory T cells. This increase may participate in the preventive effect of MP on subsequent flares in SLE. 相似文献7.
Mortality of shallow reef corals in the western Arabian Gulf following aerial exposure in winter 总被引:3,自引:0,他引:3
Aerial exposure of patch reef corals occurred in Tarut Bay, western Arabian Gulf, (Saudi Arabia) between December 1991 and May 1992, and coincided with extreme low spring tides (below the predicted lowest astronomical tide-LAT). Colonies of Acropora and Stylophora occurring at the highest levels on the tops of patch reef platforms were most affected by the low tides. Corals fully exposed to air suffered total mortality, whereas those not fully exposed suffered tissue damage to their upper parts. Exposure occurred during winter months when air and water temperatures are at their lowest in the gulf. Coupling of extremely low spring tides with wind-induced negative surges (below LAT) are not regular events but are not infrequent. Cold temperatures and exposure may act in concert to produce disproportionate mortalities of reef flat corals in the shallow coastal areas of eastern Saudi Arabia. It is highly unlikely that the Gulf War oil spill played any role in the observed damage to reef corals in the Gulf in 1992. 相似文献
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