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1.
Proc Biol Sci ; 288(1956): 20211260, 2021 08 11.
Article in English | MEDLINE | ID: mdl-34375552

ABSTRACT

The occurrence and proliferation of reef-forming corals is of vast importance in terms of the biodiversity they support and the ecosystem services they provide. The complex three-dimensional structures engineered by corals are comprised of both live and dead coral, and the function, growth and stability of these systems will depend on the ratio of both. To model how the ratio of live : dead coral may change, the 'Goldilocks Principle' can be used, where organisms will only flourish if conditions are 'just right'. With data from particle imaging velocimetry and numerical smooth particle hydrodynamic modelling with two simple rules, we demonstrate how this principle can be applied to a model reef system, and how corals are effectively optimizing their own local flow requirements through habitat engineering. Building on advances here, these approaches can be used in conjunction with numerical modelling to investigate the growth and mortality of biodiversity supporting framework in present-day and future coral reef structures.


Subject(s)
Anthozoa , Animals , Biodiversity , Coral Reefs , Ecosystem , Hydrodynamics
2.
Clin Radiol ; 76(8): 628.e1-628.e7, 2021 08.
Article in English | MEDLINE | ID: mdl-33879320

ABSTRACT

AIM: To compare ejection fraction estimated by tricuspid annular plane systolic excursion (TAPSE) using cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI) to the non-invasive reference standard, volumetric quantification of right ventricular ejection fraction (RVEF) by cardiac magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-one patients, who had undergone functional cardiac CT angiogram and cardiac MRI within 12 months, were evaluated retrospectively. Right ventricular (RV) volumes were processed using automated cardiac analysis software for CT, and manually processed by Simpson's method for MRI. MR-TAPSE was defined as the difference in length between two separate reference lines drawn at end diastole and end systole from the lateral tricuspid annulus to the right ventricular apex measured on four-chamber CINE images. CT-TAPSE was determined in an analogous manner on four-chamber reformatted images. RESULTS: MR-TAPSE correlated moderately with MR-RVEF, (r=0.57, p<0.001). CT-TAPSE was found to correlate moderately well with MR-RVEF (r=0.58, p<0.001) and CT-RVEF (r=0.63, p<0.001). Bland-Altman analysis repeated with various multiplication factors for CT-TAPSE and MR-RVEF, determined a multiplication factor of 2.7 resulted in the lowest bias (0.74%). CONCLUSION: CT-TAPSE is an easily obtainable parameter of RV function and is correlated with CT-RVEF and MR-RVEF. It can function as a quick check to rapidly validate CT right volumetry and estimate MR-RVEF.


Subject(s)
Echocardiography/methods , Magnetic Resonance Imaging/methods , Tomography, X-Ray Computed/methods , Ventricular Dysfunction, Right/diagnostic imaging , Ventricular Function, Right/physiology , Female , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Ventricular Dysfunction, Right/physiopathology
3.
Phys Rev Lett ; 126(7): 071103, 2021 Feb 19.
Article in English | MEDLINE | ID: mdl-33666466

ABSTRACT

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

4.
Chemosphere ; 257: 127109, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32497834

ABSTRACT

Used during an oil spill to minimise the formation of an oil slick, dispersants have negative biological effects on marine model organisms. However, no study has investigated the impacts of dispersants on adult sponge individuals. Here, we examine the effects of water accommodated oil fraction (WAF - oil in seawater), chemically enhanced WAF (CEWAF - oil and dispersant in seawater) and Benzo[A]Pyrene on sponge Halichondria panicea at physiological and molecular levels. Sponge clearance rate decreased sharply when exposed to WAF and CEWAF but the oil loading at which the clearance rate was reduced by 50% (ED50) was 39-fold lower in CEWAF than in WAF. Transcriptomic analysis revealed a homogenous molecular response with the greatest number of differentially expressed genes identified in CEWAF samples (1,461 genes). Specifically, genes involved in stress responses were up-regulated. This study presents evidence that the use of dispersants should be considered carefully in areas where sponges are present.


Subject(s)
Environmental Restoration and Remediation , Petroleum Pollution/analysis , Petroleum/analysis , Porifera/physiology , Water Pollutants, Chemical/analysis , Animals , Petroleum/metabolism , Seawater , Water Pollutants, Chemical/metabolism
5.
Cancer Epidemiol ; 64: 101661, 2020 02.
Article in English | MEDLINE | ID: mdl-31918181

ABSTRACT

OBJECTIVES: To investigate factors associated with larger burden of intra-anal high-grade squamous intraepithelial lesions (HSIL) in a natural history study of HSIL. METHODS: 617 gay and bisexual men (GBM) attended a baseline visit. High-resolution anoscopy-directed biopsy was performed of suspected HSIL. GBM with biopsy-confirmed HSIL (bHSIL) affecting a single-octant were compared with those who had bHSIL affecting a larger area. RESULTS: Of 196 men with bHSIL at baseline, 73 (37.2 %) had larger bHSIL burden. Larger burden was independently associated with anal HPV16 detection (aOR 2.06, 95 % CI 1.09-3.89, p = 0.026) and infection with a greater number of high-risk HPV types (aOR per type increase 1.25, 95 % CI 1.05-1.49, p-trend = 0.010). CONCLUSION: The observation that men with a larger burden of HSIL also had more risk factors for anal cancer suggests this group may warrant closer observation to ensure earlier detection, and thus improved prognosis, of individuals whose HSIL may progress to anal cancer.


Subject(s)
Anus Neoplasms/epidemiology , Homosexuality, Male/statistics & numerical data , Sexual and Gender Minorities/statistics & numerical data , Squamous Intraepithelial Lesions/epidemiology , Adult , Anus Neoplasms/pathology , Anus Neoplasms/prevention & control , Anus Neoplasms/virology , Australia/epidemiology , Cohort Studies , Female , Human papillomavirus 16/isolation & purification , Humans , Male , Middle Aged , Neoplasm Grading , Papillomavirus Infections/epidemiology , Papillomavirus Infections/pathology , Papillomavirus Infections/virology , Prevalence , Prospective Studies , Risk Factors , Squamous Intraepithelial Lesions/pathology , Squamous Intraepithelial Lesions/virology , Tumor Burden
7.
Cancer Epidemiol ; 58: 12-16, 2019 02.
Article in English | MEDLINE | ID: mdl-30439602

ABSTRACT

BACKGROUND: The association between anal high-grade squamous intraepithelial lesion (HSIL) and anal symptoms has not been systematically investigated. METHODS: The Study of Prevention of Anal Cancer is a prospective cohort study of men who have sex with men (MSM) ≥ 35 years old in Sydney, Australia. Self-reported symptoms were collected. Anal cytology and high-resolution anoscopy were undertaken. Using baseline visit data, men negative for squamous intra-epithelial lesion (SIL) were compared with men diagnosed with composite-HSIL (cytology and/or histology). Logistic regression analyses were performed to assess the association of symptoms with HSIL. RESULTS: Among 414 MSM included (composite-HSIL (n = 231); negative for SIL (n = 183)), 306 (73.9%) reported symptom(s) within the last 6 months. There was no association between any symptom and composite-HSIL. A significant association between anal lump and a larger burden of HSIL (at least 2 intra-anal octants) (anal lump within last month: p = 0.014; anal lump within last 6 months: p = 0.010) became non-significant after adjusting for HIV-status and recent anal warts (anal lump within last month: p = 0.057; anal lump within last 6 months: p = 0.182). CONCLUSIONS: Among MSM age 35 years and older, most anal symptoms are not a useful marker of anal HSIL.


Subject(s)
Anal Canal/pathology , Homosexuality, Male , Papillomavirus Infections/complications , Squamous Intraepithelial Lesions/etiology , Adult , Anus Neoplasms/diagnosis , Anus Neoplasms/etiology , Anus Neoplasms/prevention & control , Australia , Female , Humans , Male , Middle Aged , Prospective Studies , Squamous Intraepithelial Lesions/complications , Squamous Intraepithelial Lesions/diagnosis
8.
Phys Rev Lett ; 121(16): 161102, 2018 Oct 19.
Article in English | MEDLINE | ID: mdl-30387639

ABSTRACT

We report on an upward traveling, radio-detected cosmic-ray-like impulsive event with characteristics closely matching an extensive air shower. This event, observed in the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload, is consistent with a similar event reported in a previous flight. These events could be produced by the atmospheric decay of an upward-propagating τ lepton produced by a ν_{τ} interaction, although their relatively steep arrival angles create tension with the standard model neutrino cross section. Each of the two events have a posteriori background estimates of ≲10^{-2} events. If these are generated by τ-lepton decay, then either the charged-current ν_{τ} cross section is suppressed at EeV energies, or the events arise at moments when the peak flux of a transient neutrino source was much larger than the typical expected cosmogenic background neutrinos.

9.
Coral Reefs ; 37(1): 253-266, 2018.
Article in English | MEDLINE | ID: mdl-31258386

ABSTRACT

This study demonstrates how cold-water coral morphology and habitat distribution are shaped by local hydrodynamics, using high-definition video from Tisler Reef, an inshore reef in Norway. A total of 334 video frames collected on the north-west (NW) and south-east (SE) side of the reef were investigated for Lophelia pertusa coral cover and morphology and for the cover of the associated sponges Mycale lingua and Geodia sp. Our results showed that the SE side was a better habitat for L. pertusa (including live and dead colonies). Low cover of Geodia sp. was found on both sides of Tisler Reef. In contrast, Mycale lingua had higher percentage cover, especially on the NW side of the reef. Bush-shaped colonies of L. pertusa with elongated branches were the most abundant coral morphology on Tisler Reef. The highest abundance and density of this morphology were found on the SE side of the reef, while a higher proportion of cauliflower-shaped corals with short branches were found on the NW side. The proportion of very small L. pertusa colonies was also significantly higher on the SE side of the reef. The patterns in coral spatial distribution and morphology were related to local hydrodynamics-there were more frequent periods of downwelling currents on the SE side-and to the availability of suitable settling substrates. These factors make the SE region of Tisler Reef more suitable for coral growth. Understanding the impact of local hydrodynamics on the spatial extent and morphology of coral, and their relation to associated organisms such as sponges, is key to understanding the past and future development of the reef.

11.
Coral Reefs ; 36(1): 255-268, 2017.
Article in English | MEDLINE | ID: mdl-32269410

ABSTRACT

Cold-water corals form substantial biogenic habitats on continental shelves and in deep-sea areas with topographic highs, such as banks and seamounts. In the Atlantic, many reef and mound complexes are engineered by Lophelia pertusa, the dominant framework-forming coral. In this study, a variety of mapping approaches were used at a range of scales to map the distribution of both cold-water coral habitats and individual coral colonies at the Mingulay Reef Complex (west Scotland). The new ArcGIS-based British Geological Survey (BGS) seabed mapping toolbox semi-automatically delineated over 500 Lophelia reef 'mini-mounds' from bathymetry data with 2-m resolution. The morphometric and acoustic characteristics of the mini-mounds were also automatically quantified and captured using this toolbox. Coral presence data were derived from high-definition remotely operated vehicle (ROV) records and high-resolution microbathymetry collected by a ROV-mounted multibeam echosounder. With a resolution of 0.35 × 0.35 m, the microbathymetry covers 0.6 km2 in the centre of the study area and allowed identification of individual live coral colonies in acoustic data for the first time. Maximum water depth, maximum rugosity, mean rugosity, bathymetric positioning index and maximum current speed were identified as the environmental variables that contributed most to the prediction of live coral presence. These variables were used to create a predictive map of the likelihood of presence of live cold-water coral colonies in the area of the Mingulay Reef Complex covered by the 2-m resolution data set. Predictive maps of live corals across the reef will be especially valuable for future long-term monitoring surveys, including those needed to understand the impacts of global climate change. This is the first study using the newly developed BGS seabed mapping toolbox and an ROV-based microbathymetric grid to explore the environmental variables that control coral growth on cold-water coral reefs.

12.
HIV Med ; 18(5): 321-331, 2017 05.
Article in English | MEDLINE | ID: mdl-27649852

ABSTRACT

OBJECTIVES: Human papillomavirus (HPV)-associated cancers disproportionately affect those infected with HIV despite effective combination antiretroviral therapy (cART). The primary aim of this study was to quantify HPV16 and HPV52 E6-specific interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) T-cell responses, a correlate of protective immunity, in the first year following cART initiation and subsequently in those patients with suboptimal (sIR) and optimal (oIR) immune reconstitution. METHODS: Ninety-four HIV-infected patients were recruited to the study; a longitudinal cohort of patients recruited just prior to commencing cART and followed up for 48 weeks (n = 27), and a cross-sectional cohort (n = 67) consisting of patients with sIR (CD4 T-cell count < 350 cells/µL) and oIR (CD4 T-cell count > 500 cells/µL) after a minimum of 2 years on cART. Controls (n = 29) consisted of HIV-negative individuals. IFN-γ ELISPOT responses against HPV16 and HPV52 E6 were correlated to clinical characteristics, anal and oral HPV carriage, T-cell maturational subsets, markers of activation, senescence and T-regulatory cells. RESULTS: HPV16 and HPV52 E6-specific T-cell responses were detected in only one of 27 patients (3.7%) during the initial phase of immune recovery. After at least 2 years of cART, those who achieved oIR had significantly higher E6-specific responses (9 of 34; 26.5%) compared with those with sIR (2 of 32; 6.3%) (P = 0.029). Apart from higher CD4 T-cell counts and lower CD4 T-cell activation, no other immunological correlates were associated with the detection of HPV16 and HPV52 E6-specific responses. CONCLUSIONS: HPV16 and HPV52 E6-specific IFN-γ T-cell responses, a correlate of protective immunity, were detected more frequently among HIV-infected patients who achieved optimal immune recovery on cART (26.5%) compared with those with suboptimal recovery (6.3%).


Subject(s)
Anti-Retroviral Agents/therapeutic use , Antiretroviral Therapy, Highly Active , HIV Infections/complications , HIV Infections/drug therapy , Oncogene Proteins, Viral/immunology , Papillomaviridae/immunology , Papillomavirus Infections/immunology , Adult , Cross-Sectional Studies , Enzyme-Linked Immunospot Assay , Female , Genotype , Humans , Interferon-gamma/metabolism , Leukocytes, Mononuclear/immunology , Longitudinal Studies , Male , Middle Aged
13.
J Fish Biol ; 89(2): 1473-81, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27350418

ABSTRACT

Highly localized concentrations of elasmobranch egg capsules of the deep-water skate Bathyraja richardsoni were discovered during the first remotely operated vehicle (ROV) survey of the Hebrides Terrace Seamount in the Rockall Trough, north-east Atlantic Ocean. Conductivity-temperature-depth profiling indicated that the eggs were bathed in a specific environmental niche of well-oxygenated waters between 4·20 and 4·55° C, and salinity 34·95-35·06, on a coarse to fine-grained sandy seabed on the seamount's eastern flank, whereas a second type of egg capsule (possibly belonging to the skate Dipturus sp.) was recorded exclusively amongst the reef-building stony coral Solenosmilia variabilis. The depths of both egg-laying habitats (1489-1580 m) provide a de facto refuge from fisheries mortality for younger life stages of these skates.


Subject(s)
Ecosystem , Ovum , Skates, Fish , Animals , Anthozoa , Atlantic Ocean , Elasmobranchii , Female , Fisheries , Male , Oviposition , Salinity , Water
14.
Atmos Chem Phys ; 16(4): 2597-2610, 2016.
Article in English | MEDLINE | ID: mdl-29619046

ABSTRACT

The chemical link between isoprene and formaldehyde (HCHO) is a strong, non-linear function of NOx (= NO + NO2). This relationship is a linchpin for top-down isoprene emission inventory verification from orbital HCHO column observations. It is also a benchmark for overall photochemical mechanism performance with regard to VOC oxidation. Using a comprehensive suite of airborne in situ observations over the Southeast U.S., we quantify HCHO production across the urban-rural spectrum. Analysis of isoprene and its major first-generation oxidation products allows us to define both a "prompt" yield of HCHO (molecules of HCHO produced per molecule of freshly-emitted isoprene) and the background HCHO mixing ratio (from oxidation of longer-lived hydrocarbons). Over the range of observed NOx values (roughly 0.1 - 2 ppbv), the prompt yield increases by a factor of 3 (from 0.3 to 0.9 ppbv ppbv-1), while background HCHO increases by a factor of 2 (from 1.6 to 3.3 ppbv). We apply the same method to evaluate the performance of both a global chemical transport model (AM3) and a measurement-constrained 0-D steady state box model. Both models reproduce the NOx dependence of the prompt HCHO yield, illustrating that models with updated isoprene oxidation mechanisms can adequately capture the link between HCHO and recent isoprene emissions. On the other hand, both models under-estimate background HCHO mixing ratios, suggesting missing HCHO precursors, inadequate representation of later-generation isoprene degradation and/or under-estimated hydroxyl radical concentrations. Detailed process rates from the box model simulation demonstrate a 3-fold increase in HCHO production across the range of observed NOx values, driven by a 100% increase in OH and a 40% increase in branching of organic peroxy radical reactions to produce HCHO.

15.
Atmos Meas Tech ; 9(7): 3063-3093, 2016.
Article in English | MEDLINE | ID: mdl-29619117

ABSTRACT

Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions.

16.
Pregnancy Hypertens ; 5(4): 273-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26597740

ABSTRACT

BACKGROUND: Epidemiological findings suggest that the link between poverty and pre-eclampsia might be dietary calcium deficiency. Calcium supplementation has been associated with a modest reduction in pre-eclampsia, and also in blood pressure (BP). METHODS: This exploratory sub-study of the WHO Calcium and Pre-eclampsia (CAP) trial aims to determine the effect of 500mg/day elemental calcium on the blood pressure of non-pregnant women with previous pre-eclampsia. Non-pregnant women with at least one subsequent follow-up trial visit at approximately 12 or 24weeks after randomization were included. RESULTS: Of 836 women randomized by 9 September 2014, 1st visit data were available in 367 women of whom 217 had previously had severe pre-eclampsia, 2nd visit data were available in 201 women. There was an overall trend to reduced BP in the calcium supplementation group (1-2.5mmHg) although differences were small and not statistically significant. In the subgroup with previous severe pre-eclampsia, the mean diastolic BP change in the calcium group (-2.6mmHg) was statistically larger than in the placebo group (+0.8mmHg), (mean difference -3.4, 95% CI -0.4 to -6.4; p=0.025). The effect of calcium on diastolic BP at 12weeks was greater than in those with non-severe pre-eclampsia (p=0.020, ANOVA analysis). CONCLUSIONS: There is an overall trend to reduced BP but only statistically significant in the diastolic BP of women with previous severe pre-eclampsia. This is consistent with our hypothesis that this group is more sensitive to calcium supplementation, however results need to be interpreted with caution.


Subject(s)
Blood Pressure Determination , Blood Pressure/drug effects , Bone Density Conservation Agents/administration & dosage , Calcium, Dietary/administration & dosage , Pre-Eclampsia/prevention & control , Pregnancy Complications, Cardiovascular/prevention & control , Adult , Argentina , Blood Pressure Determination/methods , Double-Blind Method , Female , Humans , Pregnancy , Risk Assessment , South Africa , Treatment Outcome , World Health Organization , Zimbabwe
17.
Proc Biol Sci ; 282(1813): 20150990, 2015 Aug 22.
Article in English | MEDLINE | ID: mdl-26290073

ABSTRACT

Cold-water corals, such as Lophelia pertusa, are key habitat-forming organisms found throughout the world's oceans to 3000 m deep. The complex three-dimensional framework made by these vulnerable marine ecosystems support high biodiversity and commercially important species. Given their importance, a key question is how both the living and the dead framework will fare under projected climate change. Here, we demonstrate that over 12 months L. pertusa can physiologically acclimate to increased CO2, showing sustained net calcification. However, their new skeletal structure changes and exhibits decreased crystallographic and molecular-scale bonding organization. Although physiological acclimatization was evident, we also demonstrate that there is a negative correlation between increasing CO2 levels and breaking strength of exposed framework (approx. 20-30% weaker after 12 months), meaning the exposed bases of reefs will be less effective 'load-bearers', and will become more susceptible to bioerosion and mechanical damage by 2100.


Subject(s)
Anthozoa/physiology , Climate Change , Seawater/chemistry , Acclimatization , Animals , Anthozoa/growth & development , Atlantic Ocean , Calcification, Physiologic , Carbon Dioxide/metabolism , Coral Reefs , Hydrogen-Ion Concentration , Oceans and Seas , Respiration , Scotland , Temperature
18.
Epidemiol Infect ; 143(16): 3459-67, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25907106

ABSTRACT

The incidence of recreational water-associated outbreaks in the United States has significantly increased, driven, at least in part, by outbreaks both caused by Cryptosporidium and associated with treated recreational water venues. Because of the parasite's extreme chlorine tolerance, transmission can occur even in well-maintained treated recreational water venues (e.g. pools) and a focal cryptosporidiosis outbreak can evolve into a community-wide outbreak associated with multiple recreational water venues and settings (e.g. childcare facilities). In August 2004 in Auglaize County, Ohio, multiple cryptosporidiosis cases were identified and anecdotally linked to pool A. Within 5 days of the first case being reported, pool A was hyperchlorinated to achieve 99·9% Cryptosporidium inactivition. A case-control study was launched to epidemiologically ascertain the outbreak source 11 days later. A total of 150 confirmed and probable cases were identified; the temporal distribution of illness onset was peaked, indicating a point-source exposure. Cryptosporidiosis was significantly associated with swimming in pool A (matched odds ratio 121·7, 95% confidence interval 27·4-∞) but not with another venue or setting. The findings of this investigation suggest that proactive implementation of control measures, when increased Cryptosporidium transmission is detected but before an outbreak source is epidemiologically ascertained, might prevent a focal cryptosporidiosis outbreak from evolving into a community-wide outbreak.


Subject(s)
Cryptosporidiosis/epidemiology , Cryptosporidiosis/prevention & control , Cryptosporidium/isolation & purification , Disease Transmission, Infectious/prevention & control , Fresh Water/parasitology , Infection Control/methods , Swimming Pools , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Cryptosporidiosis/transmission , Female , Halogenation , Humans , Infant , Male , Middle Aged , Ohio/epidemiology , Young Adult
19.
Mol Ecol ; 24(10): 2379-91, 2015 May.
Article in English | MEDLINE | ID: mdl-25846956

ABSTRACT

Host shifts are a key mechanism of parasite evolution and responsible for the emergence of many economically important pathogens. Varroa destructor has been a major factor in global honeybee (Apis mellifera) declines since shifting hosts from the Asian honeybee (Apis cerana) > 50 years ago. Until recently, only two haplotypes of V. destructor (Korea and Japan) had successfully host shifted to A. mellifera. In 2008, the sister species V. jacobsoni was found for the first time parasitizing A. mellifera in Papua New Guinea (PNG). This recent host shift presents a serious threat to world apiculture but also provides the opportunity to examine host shifting in this system. We used 12 microsatellites to compare genetic variation of V. jacobsoni on A. mellifera in PNG with mites on A. cerana in both PNG and surrounding regions. We identified two distinct lineages of V. jacobsoni reproducing on A. mellifera in PNG. Our analysis indicated independent host shift events have occurred through small numbers of mites shifting from local A. cerana populations. Additional lineages were found in the neighbouring Papua and Solomon Islands that had partially host shifted to A. mellifera, that is producing immature offspring on drone brood only. These mites were likely in transition to full colonization of A. mellifera. Significant population structure between mites on the different hosts suggested host shifted V. jacobsoni populations may not still reproduce on A. cerana, although limited gene flow may exist. Our studies provide further insight into parasite host shift evolution and help characterize this new Varroa mite threat to A. mellifera worldwide.


Subject(s)
Bees/parasitology , Genetic Variation , Host Specificity , Varroidae/genetics , Animals , Bayes Theorem , Gene Flow , Genetics, Population , Haplotypes , Host-Parasite Interactions/genetics , Microsatellite Repeats , Models, Genetic , Papua New Guinea , Sequence Analysis, DNA
20.
Sci Rep ; 4: 6782, 2014 Oct 27.
Article in English | MEDLINE | ID: mdl-25345760

ABSTRACT

The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no 'self-recognition' on a broad species level. This study reveals areas of 'flawless' skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of 'self' between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.


Subject(s)
Anthozoa , Ecosystem , Oceans and Seas , Animals , Anthozoa/classification , Anthozoa/genetics , Coral Reefs , Geography
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