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1.
Nature ; 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-39048015

ABSTRACT

Of the ~25 directly imaged planets to date, all are younger than 500Myr and all but 6 are younger than 100Myr1. Eps Ind A (HD209100, HIP108870) is a K5V star of roughly solar age (recently derived as 3.7-5.7Gyr2 and 3.5 - 1.3 + 0.8 Gyr3). A long-term radial velocity trend 4,5 as well as an astrometric acceleration6,7 led to claims of a giant planet2,8,9 orbiting the nearby star (3.6384±0.0013pc10). Here we report JWST coronagraphic images that reveal a giant exoplanet which is consistent with these radial and astrometric measurements, but inconsistent with the previously claimed planet properties. The new planet has temperature ~275K, and is remarkably bright at 10.65µm and 15.50µm. Non-detections between 3.5-5µm indicate an unknown opacity source in the atmosphere, possibly suggesting a high metallicity, high carbon-to-oxygen ratio planet. The best-fit temperature of the planet is consistent with theoretical thermal evolution models, which are previously untested at this temperature range. The data indicates that this is likely the only giant planet in the system and we therefore refer to it as "b", despite it having significantly different orbital properties than the previously claimed planet "b".

2.
Mar Pollut Bull ; 173(Pt A): 112940, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34537571

ABSTRACT

The development of desalination has been essential to the rapid economic development of the countries bordering the Arabian Gulf. The current production capacity of sea water desalination plants drawing water from Gulf is over 20 million m3 day-1, which may rise to 80 million m3 day-1 by 2050. Whilst supporting aspects of sustainable development related to water and sanitation, desalination impacts the marine environment through impingement and entrainment of organisms in intakes, and through thermal, brine and chemical discharges. This may compromise other objectives for sustainable development related to sustainable use of the oceans. Under business as usual scenarios, by 2050, the impact of individual desalination plants will combine causing a regional scale impact. Without mitigating actions to avoid the business as usual scenario, by 2050, desalination in combination with climate change, will elevate coastal water temperatures across more than 50% of the Gulf by at least 3 °C, and a volume of water equivalent to more than a third of the total volume of water between 0 and 10 m deep will pass through desalination plants each year. This will adversely impact the coastal ecosystem of the Gulf, with impacts on biodiversity, fisheries and coastal communities and may cause potential loss of species and habitats from the Gulf. Given the significant implications of these preliminary findings, and in light of the precautionary approach to management, it is recommended that mitigating options addressing behavioural, regulatory and technological change are rapidly evaluated and implemented to avoid the development of desalination in the region along a business as usual pathway, and multidisciplinary research studies should be conducted to reduce uncertainty in predictions of future impacts.


Subject(s)
Ecosystem , Sustainable Development , Biodiversity , Climate Change , Seawater
3.
Mar Pollut Bull ; 167: 112319, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33845352

ABSTRACT

The United Arab Emirates (UAE) host valuable coastal and marine biodiversity that is subjected to multiple pressures under extreme conditions. To mitigate impacts on marine ecosystems, the UAE protects almost 12% of its Exclusive Economic Zone. This study mapped and validated the distribution of key coastal and marine habitats, species and critical areas for their life cycle in the Gulf area of the UAE. We identified gaps in the current protection of these ecological features and assessed the quality of the data used. The overall dataset showed good data quality, but deficiencies in information for the coastline of the north-western emirates. The existing protected areas are inadequate to safeguard key ecological features such as mangroves and coastal lagoons. This study offers a solid basis to understand the spatial distribution and protection of marine biodiversity in the UAE. This information should be considered for implementing effective conservation planning and ecosystem-based management.


Subject(s)
Conservation of Natural Resources , Ecosystem , Biodiversity , United Arab Emirates
4.
Sci Rep ; 7(1): 2428, 2017 05 25.
Article in English | MEDLINE | ID: mdl-28546553

ABSTRACT

Coral reefs are threatened by climate change as coral-algal symbioses are currently living close to their upper thermal limits. The resilience of the algal partner plays a key role in determining the thermal tolerance of the coral holobiont and therefore, understanding the acclimatory limits of present day coral-algal symbioses is fundamental to forecasting corals' responses to climate change. This study characterised the symbiont community in a highly variable and thermally extreme (Max = 37.5 °C, Min = 16.8 °C) lagoon located in the southern Persian/Arabian Gulf using next generation sequencing of ITS2 amplicons. Despite experiencing extreme temperatures, severe bleaching and many factors that would be expected to promote the presence of, or transition to clade D dominance, the symbiont communities of the lagoon remain dominated by the C3 variant, Symbiodinium thermophilum. The stability of this symbiosis across multiple genera with different means of symbiont transmission highlights the importance of Symbiodinium thermophilum for corals living at the acclimatory limits of modern day corals. Corals in this extreme environment did not undergo adaptive bleaching, suggesting they are living at the edge of their acclimatory potential and that this valuable source of thermally tolerant genotypes may be lost in the near future under climate change.


Subject(s)
Anthozoa/physiology , Coral Reefs , Dinoflagellida/physiology , Symbiosis , Animals , DNA, Intergenic , Environment , Temperature
5.
Mar Pollut Bull ; 105(2): 498-506, 2016 Apr 30.
Article in English | MEDLINE | ID: mdl-26573133

ABSTRACT

Oman contains diverse and abundant reef coral communities that extend along a coast that borders three environmentally distinct water bodies, with corals existing under unique and often stressful environmental conditions. In recent years Oman's reefs have undergone considerable change due to recurrent predatory starfish outbreaks, cyclone damage, harmful algal blooms, and other stressors. In this review we summarize current knowledge of the biology and status of corals in Oman, particularly in light of recent stressors and projected future threats, and examine current reef management practices. Oman's coral communities occur in marginal environmental conditions for reefs, and hence are quite vulnerable to anthropogenic effects. We recommend a focus on developing conservation-oriented coral research to guide proactive management and expansion of the number and size of designated protected areas in Oman, particularly those associated with critical coral habitat.


Subject(s)
Anthozoa/physiology , Biodiversity , Conservation of Natural Resources , Coral Reefs , Animal Distribution , Animals , Oman , Population Dynamics
6.
Sci Rep ; 4: 7484, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25501043

ABSTRACT

Despite a wealth of information on sexual reproduction in scleractinian corals, there are regional gaps in reproductive records. In the Gulf of the Oman in the Arabian Sea, reproductive timing was assessed in four common species of broadcast spawning corals using field surveys of gamete maturity and aquarium observations of spawning activity. The appearance of mature gametes within the same month for Acropora downingi, A. hemprichii, Cyphastrea microphthalma and Platygyra daedalea (≥ 75% of colonies, n = 848) indicated a synchronous and multi-specific spawning season. Based on gamete disappearance and direct observations, spawning predominantly occurred during April in 2013 (75-100% of colonies) and May in 2014 (77-94% of colonies). The difference in spawning months between survey years was most likely explained by sea temperature and the timing of lunar cycles during late-stage gametogenesis. These reproductive records are consistent with a latitudinal gradient in peak broadcast spawning activity at reefs in the northwestern Indian Ocean which occurs early in the year at low latitudes (January to March) and progressively later in the year at mid (March to May) and high (June to September) latitudes.


Subject(s)
Breast Neoplasms/drug therapy , Animals , Apoptosis , Blotting, Western , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Cell Adhesion , Cell Cycle , Cell Movement , Cell Proliferation , Female , Flow Cytometry , Fluorescent Antibody Technique , Humans , Immunoenzyme Techniques , Mice , Mice, Inbred BALB C , Mice, Nude , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
7.
J Fish Biol ; 77(8): 1931-47, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21078099

ABSTRACT

To examine the role of climatic extremes in structuring reef fish communities in the Arabian region, reef fish communities were visually surveyed at four sites within the southern Persian Gulf (also known as the Arabian Gulf and The Gulf), where sea-surface temperatures are extreme (range: 12-35° C annually), and these were compared with communities at four latitudinally similar sites in the biogeographically connected Gulf of Oman, where conditions are more moderate (range: 22-31° C annually). Although sites were relatively similar in the cover and composition of coral communities, substantial differences in the structure and composition of associated fish assemblages were apparent. Fish assemblages in the southern Persian Gulf held significantly lower estimates of abundance, richness and biomass, with significantly higher abundances of smaller sized individuals than Gulf of Oman assemblages. Functionally, southern Persian Gulf sites held significantly lower abundances of nearly all the common fish trophic guilds found on Gulf of Oman sites, although higher abundances of herbivorous grazers were apparent. These results suggest the potential for substantial changes in the structure of reef-associated fish communities, independent of changes in habitat within an environment of increasing fluctuations in oceanic climate.


Subject(s)
Biodiversity , Climate Change , Fishes/physiology , Animals , Coral Reefs , Indian Ocean , Population Density
8.
J Infect Dis ; 174(6): 1279-87, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8940219

ABSTRACT

From 1990 to 1993, an outbreak of respiratory Acinetobacter baumannii infection occurred in five intensive care units (ICUs) of a tertiary care center. A. baumannii was subsequently isolated from disinfected temperature probes and ventilator circuits. Pulsed-field gel electrophoresis suggested that a single strain accounted for 93% of patient isolates and 88% of environmental isolates. Univariate risk factors for A. baumannii acquisition were tracheostomy (P < .01), ventilation >3 days (P < .01), dialysis (P = .03), Stenotrophomonas maltophilia respiratory colonization (P = .02), parenteral nutrition (P = .05), and enteric feeding (P < .01). Logistic regression analysis showed duration of ventilation and enteric feeding to be independent risk factors. The outbreak strain was relatively antibiotic-susceptible, but the mortality attributable to respiratory A. baumannii acquisition was 23%. Only the APACHE II score was independently associated with increased mortality. Multifaceted control measures, including gas sterilization of temperature probes, terminated the outbreak.


Subject(s)
Acinetobacter Infections/drug therapy , Acinetobacter Infections/epidemiology , Disease Outbreaks , Intensive Care Units , Acinetobacter Infections/mortality , Acinetobacter Infections/transmission , Aged , Case-Control Studies , Cross Infection/microbiology , Dialysis/adverse effects , Drug Resistance, Microbial , Electrophoresis, Gel, Pulsed-Field , Enteral Nutrition/adverse effects , Female , Gram-Negative Bacterial Infections/complications , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Parenteral Nutrition/adverse effects , Polymorphism, Restriction Fragment Length , Regression Analysis , Respiration, Artificial/adverse effects , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/transmission , Risk Factors , Tracheostomy/adverse effects
9.
Appl Opt ; 24(15): 2450-5, 1985 Aug 01.
Article in English | MEDLINE | ID: mdl-18223906

ABSTRACT

The use of resonant piezoceramic transducers in the pulsed photoacoustic technique and the effect of the focusing of the probing beam have been investigated experimentally. The improved sensitivity for resonant detection and for more tightly focused probing beams has been verified. The constraints imposed when working with tightly focused beams are noted.

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