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2.
Science ; 369(6510): 1497-1500, 2020 09 18.
Article in English | MEDLINE | ID: mdl-32943524

ABSTRACT

Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary nebula (PN) could be due to binary interactions. We observed a sample of AGB stars with the Atacama Large Millimeter/submillimeter Array (ALMA) and found that their winds exhibit distinct nonspherical geometries with morphological similarities to planetary nebulae (PNe). We infer that the same physics shapes both AGB winds and PNe; additionally, the morphology and AGB mass-loss rate are correlated. These characteristics can be explained by binary interaction. We propose an evolutionary scenario for AGB morphologies that is consistent with observed phenomena in AGB stars and PNe.

3.
Aust Vet J ; 97(10): 394-397, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31364763

ABSTRACT

OBJECTIVE: Updating veterinarians (vets) on the latest biosecurity resources, information and alerts is important to ensure protection of domesticated and native animals. This preliminary questionnaire aimed to better understand the communication preferences of Australian-registered vets for biosecurity information, and their trust of these sources. METHODS: An online questionnaire asking vets about their current communication preferences for biosecurity information, and their level of trust of these was created and distributed to Australian-registered vets. RESULTS: Survey respondents (158) use and highly trust communication from (in order) vet and animal health organisations, vet surgeons' boards, the scientific literature, and government agencies. CONCLUSIONS: This preliminary study identifies that using vet surgeon's boards, government agencies and vet and animal health organisations may be an effective means for communicating biosecurity information to vets. Future research should consider which sources vets trust and why, to facilitate effective communication to them and the clients they serve.


Subject(s)
Communicable Diseases , Information Dissemination/methods , Veterinarians/statistics & numerical data , Animals , Australia , Communication , Humans , Surveys and Questionnaires
4.
Article in English | MEDLINE | ID: mdl-38915817

ABSTRACT

Here we report on the microstructural factors influencing the formation of the interfacial exchange bias effect in three-dimensional transition-metal-based nanocomposite systems, with relevance to permanent magnet applications. Bulk phase-separated nanocomposites consisting of the ferromagnetic α -Fe and metastable antiferromagnetic γ - Fe 70 Mn 30 phases exhibit a notable low-temperature exchange bias and substantial coercivity ( H ex = 24.6 kA / m , H C = 95.7 kA / m ) as well as a near room-temperature blocking temperature. Structural investigation by synchrotron X-ray diffraction, neutron scattering, and transmission electron microscopy confirm that the ferromagnetic α -Fe phase nucleates as small precipitates ( d ≈ 50 nm ) at the grain boundaries of the antiferromagnetic γ - Fe 70 Mn 30 grains ( d = 360 - 740 nm ) and grows anisotropically upon heat treatment, resulting in an elliptical geometry. These results indicate that optimization of the exchange bias effect in bulk nanocomposite systems may be achieved through maximizing the surface-to-volume ratio of ferromagnetic precipitates in an antiferromagnetic matrix, enhancing the magnetocrystalline anisotropy of the antiferromagnetic phase to facilitate interfacial pinning and ensuring a balanced distribution of the ferromagnetic and antiferromagnetic phases. This work further clarifies critical factors influencing the formation of an exchange bias in an inexpensive transition-metal-based bulk nanocomposite system with potential for scalable production.

5.
Transbound Emerg Dis ; 65(2): e470-e477, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29250929

ABSTRACT

Mortality caused by rabbit haemorrhagic disease virus (RHDV) in wild rabbits is reduced in parts of Australia where the related, non-pathogenic calicivirus RCV-A1 is endemic. Laboratory experiments previously showed that prior infection with RCV-A1 enabled rabbits to better withstand subsequent infection with highly virulent RHDV, and this was assumed to explain higher survival. Here, we analyse serological data from the field suggesting that reduced mortality rates among wild rabbits may also result from rabbits previously infected with RCV-A1 having a reduced likelihood of RHDV infection. We discuss the possible mechanisms underlying this finding and its implications. The methods we describe for analysing field data gave far greater insights into epidemiological processes and virus interactions than gained from reporting basic seroprevalence rates alone.


Subject(s)
Antibodies, Viral/blood , Caliciviridae Infections/mortality , Caliciviridae Infections/veterinary , Cross Protection , Hemorrhagic Disease Virus, Rabbit/immunology , Animals , Australia/epidemiology , Caliciviridae Infections/immunology , Enzyme-Linked Immunosorbent Assay/veterinary , Hemorrhagic Disease Virus, Rabbit/pathogenicity , Rabbits , Seroepidemiologic Studies
6.
Open Biol ; 6(3)2016 Mar.
Article in English | MEDLINE | ID: mdl-26935951

ABSTRACT

Woodlice efficiently sequester copper (Cu) in 'cuprosomes' within hepatopancreatic 'S' cells. Binuclear 'B' cells in the hepatopancreas form iron (Fe) deposits; these cells apparently undergo an apocrine secretory diurnal cycle linked to nocturnal feeding. Synchrotron-based µ-focus X-ray spectroscopy undertaken on thin sections was used to characterize the ligands binding Cu and Fe in S and B cells of Oniscus asellus (Isopoda). Main findings were: (i) morphometry confirmed a diurnal B-cell apocrine cycle; (ii) X-ray fluorescence (XRF) mapping indicated that Cu was co-distributed with sulfur (mainly in S cells), and Fe was co-distributed with phosphate (mainly in B cells); (iii) XRF mapping revealed an intimate morphological relationship between the basal regions of adjacent S and B cells; (iv) molecular modelling and Fourier transform analyses indicated that Cu in the reduced Cu(+) state is mainly coordinated to thiol-rich ligands (Cu-S bond length 2.3 Å) in both cell types, while Fe in the oxidized Fe(3+) state is predominantly oxygen coordinated (estimated Fe-O bond length of approx. 2 Å), with an outer shell of Fe scatterers at approximately 3.05 Å; and (v) no significant differences occur in Cu or Fe speciation at key nodes in the apocrine cycle. Findings imply that S and B cells form integrated unit-pairs; a functional role for secretions from these cellular units in the digestion of recalcitrant dietary components is hypothesized.


Subject(s)
Copper/metabolism , Hepatopancreas/metabolism , Iron/metabolism , Isopoda/metabolism , Animals , B-Lymphocytes/cytology , B-Lymphocytes/metabolism , Binding Sites , Copper/analysis , Hepatopancreas/chemistry , Hepatopancreas/ultrastructure , Iron/analysis , Isopoda/chemistry , Isopoda/ultrastructure , Oxidation-Reduction , Phosphates/analysis , Phosphates/metabolism , Spectrometry, X-Ray Emission , Sulfur/analysis , Sulfur/metabolism
7.
Ir Med J ; 107(7): 215-6, 2014.
Article in English | MEDLINE | ID: mdl-25226719

ABSTRACT

Basal-cell carcinoma (BCC) is the most commonly diagnosed malignancy, comprising over 80 per thousand of non-melanoma skin cancers. Surgical excision is adequate treatment for most BCC's. Options are however limited for the minority of patients presenting with locally advanced inoperable or metastatic BCC. The Hedgehog signalling pathway is a critical driver in the pathogenesis of both sporadic and hereditary BCC. On 31st January 2012, based on a phase II clinical trial the US Food and Drug Administration approved Vismodegib (Erivedge, Roche) a first-in-class, small-molecule oral Hedgehog-inhibitor for the treatment of locally advanced inoperable and metastatic BCC. We present our experience treating the first Irish patient with this agent.


Subject(s)
Anilides/therapeutic use , Antineoplastic Agents/therapeutic use , Carcinoma, Basal Cell/drug therapy , Pyridines/therapeutic use , Skin Neoplasms/drug therapy , Anilides/adverse effects , Antineoplastic Agents/adverse effects , Carcinoma, Basal Cell/pathology , Compassionate Use Trials , Humans , Male , Middle Aged , Pyridines/adverse effects , Skin Neoplasms/pathology , Treatment Outcome
8.
Appl Environ Microbiol ; 79(7): 2484-7, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23377935

ABSTRACT

Small-subunit (SSU) rRNA gene sequences associated with the phylum Armatimonadetes were analyzed using multiple phylogenetic methods, clarifying both the phylum boundary and the affiliation of previously ambiguous groupings. Here we define the Armatimonadetes as 10 class-level groups and reclassify two previously associated groups as candidate divisions WS1 and FBP.


Subject(s)
Bacteria/classification , Bacteria/genetics , Phylogeny , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
10.
J Appl Microbiol ; 112(3): 436-42, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22321006

ABSTRACT

AIMS: The aim of this study was to isolate lactic acid bacteria from chilli waste and evaluate metabolites produced for the ability to arrest wood decay. METHODS AND RESULTS: Using an optical density screening method, one bacterium (isolate C11) was identified as having pronounced antifungal properties against Oligoporus placenta. This isolate was identified as Lactobacillus brevis by 16S rRNA gene sequencing. To determine antifungal activity in wood, Pinus radiata blocks were impregnated with Lact. brevis [C11] cell-free supernatant and exposed to brown rot fungi O. placenta, Antrodia xantha and Coniophora puteana. The treated timber demonstrated resistance to degradation from all fungi. The antifungal metabolites were heat stable and not affected by proteinase K, but were affected by neutralization with NaOH suggesting the metabolites were of an acidic nature. The presence of lactic and acetic acid was confirmed by HPLC analysis. CONCLUSIONS: Lactobacillus brevis [C11] produced acidic metabolites that were able to inhibit the growth of wood decay fungi and subsequent wood decay. SIGNIFICANCE AND IMPACT OF THE STUDY: Traditional wood treatments are becoming an environmental issue as the public demands more benign options. The use of lactic acid bacteria which are considered safe for general use is a potential alternative to the conventional heavy metal chemicals currently in use.


Subject(s)
Antifungal Agents/metabolism , Basidiomycota/growth & development , Capsicum/microbiology , Levilactobacillus brevis/isolation & purification , Pinus/microbiology , Wood/microbiology , Acetic Acid/metabolism , Biodegradation, Environmental , Lactic Acid/metabolism , Levilactobacillus brevis/metabolism
11.
Br J Dermatol ; 165(5): 1124-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21711328

ABSTRACT

BACKGROUND: Dermatological teaching has traditionally stressed that complete skin examination is essential in the assessment of patients with potential skin disease. OBJECTIVES: To determine whether complete skin examination results in increased diagnoses of skin malignancies that would not have been discovered otherwise. METHODS: New patients (n = 483) attending a dermatology clinic in a university teaching hospital and private dermatology practice had a complete skin examination, as is our normal practice. These patients were seen over a 9-month period (January-September 2009). All patients were examined by the same consultant dermatologist. Data were collected on patients' sex, age, presenting complaint and findings on complete skin examination. RESULTS: Two nodular malignant melanomas with mean Breslow thickness of 0·6 mm (0·4%) and one melanoma in situ were identified at sites distant from the patient's presenting complaint. Sixteen patients (3·3%) had a basal cell carcinoma that would not have been discovered if the presenting lesion alone had been examined. Thirty-three patients (6·8%) had actinic keratoses or squamous cell carcinoma in situ and nine (1·9%) had dysplastic naevi. A further 21 patients (4·3%) had a suspicious lesion biopsied or excised with subsequent benign histology. Seventy-three patients (15·1%) had other benign dermatological diagnoses requiring treatment or investigation. CONCLUSIONS: In a 9-month period, in a sample of 483 new patients, three patients (0·6%) had potentially lethal skin malignancies identified that would not have been diagnosed without a complete skin examination. Sixteen (3·3%) patients had basal cell carcinomas that would have been missed without complete skin examination. This study confirms the traditional teaching that complete skin examination has the potential to reduce morbidity and mortality from cutaneous malignancy.


Subject(s)
Physical Examination/methods , Skin Neoplasms/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Early Detection of Cancer , Female , Humans , Male , Middle Aged , Young Adult
12.
J Microbiol Methods ; 80(1): 70-5, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19903500

ABSTRACT

RNA based stable isotope probing (SIP) facilitates the detection and identification of active members of microbial populations that are involved in the assimilation of an isotopically labeled compound. (15)N-RNA-SIP is a new method that has been discussed in recent literature but has not yet been tested. Herein, we define the limitations to using (15)N-labeled substrates for SIP and propose modifications to compensate for some of these shortcomings. We have used (15)N-RNA-SIP as a tool for analysing mixed bacterial populations that use nitrogen substrates. After incubating mixed microbial communities with (15)N-ammonium chloride or (15)N(2) we assessed the fractionation resolution of (15)N-RNA by isopycnic centrifugation in caesium trifluoroacetate (CsTFA) gradients. We found that the more isotopic label incorporated, the further the buoyant density (BD) separation between (15)N- and (14)N-RNA, however it was not possible to resolve the labeled from unlabeled RNA definitively through gradient fractionation. Terminal-restriction fragment length polymorphism (T-RFLP) analysis of the extracted RNA and fluorescent in situ hybridisation (FISH) analysis of the enrichment cultures provided some insight into the organisms involved in nitrogen fixation. This approach is not without its limitations and will require further developments to assess its applicability to other nitrogen-fixing environments.


Subject(s)
Bacteria/chemistry , Isotope Labeling/methods , Nitrogen Isotopes/chemistry , RNA, Bacterial/chemistry , Bacteria/genetics , Bacteria/metabolism , Centrifugation, Density Gradient , Nitrogen Isotopes/metabolism , RNA, Bacterial/genetics
13.
Heart ; 94(8): 978-83, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18625792

ABSTRACT

It has been known for some time that the heart rotates during the cardiac cycle in concert with radial and longitudinal motion. With advances in imaging technology, it has been appreciated that the apex and base of the heart rotate in different directions, resulting in a twisting or torsional motion. A new echocardiographic technique, "speckle tracking imaging", permits accurate quantification of this motion. Torsion as well as the timing and magnitude of the rate of torsion (torsional velocity) may provide important new insights into cardiac physiology and disease.


Subject(s)
Heart/physiology , Rotation , Adolescent , Adult , Aging/physiology , Child , Child, Preschool , Echocardiography/methods , Heart Diseases/diagnostic imaging , Heart Diseases/physiopathology , Humans , Image Interpretation, Computer-Assisted/methods , Infant , Infant, Newborn , Middle Aged , Myocardial Contraction/physiology
14.
Nature ; 441(7090): 203-6, 2006 May 11.
Article in English | MEDLINE | ID: mdl-16688173

ABSTRACT

Meteorites provide a sample of Solar System bodies and so constrain the types of objects that have collided with Earth over time. Meteorites analysed to date, however, are unlikely to be representative of the entire population and it is also possible that changes in their nature have occurred with time. Large objects are widely believed to be completely melted or vaporized during high-angle impact with the Earth. Consequently, identification of large impactors relies on indirect chemical tracers, notably the platinum-group elements. Here we report the discovery of a large (25-cm), unaltered, fossil meteorite, and several smaller fragments within the impact melt of the giant (> 70 km diameter), 145-Myr-old Morokweng crater, South Africa. The large fragment (clast) resembles an LL6 chondrite breccia, but contains anomalously iron-rich silicates, Fe-Ni sulphides, and no troilite or metal. It has chondritic chromium isotope ratios and identical platinum-group element ratios to the bulk impact melt. These features allow the unambiguous characterization of an impactor at a large crater. Furthermore, the unusual composition of the meteorite suggests that the Morokweng asteroid incorporated part of the LL chondrite parent body not represented by objects at present reaching the Earth.

15.
Comp Biochem Physiol A Mol Integr Physiol ; 136(4): 895-902, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14667852

ABSTRACT

Energy demands in the platypus are likely to increase in the breeding season, which occurs from winter to early spring. Glucocorticoids, which play a major role in energy mobilisation, were measured in consecutive blood samples from free-ranging adults at approximately monthly intervals throughout the year. Glucose and free fatty acids were also measured in some samples. Plasma concentrations of glucocorticoids rose significantly during the first 30 min after capture, accompanied by a rise in free fatty acids, but no corresponding increase in glucose concentrations. We observed a strong pattern in plasma glucocorticoids in samples collected within 15 min of capture (indicative of pre-disturbance concentrations) in different phases of the annual reproductive cycle, with significantly higher levels in both males and females in the breeding season compared to the non-breeding season. These data, and the decline in tail fat stores that occur towards the end of the mating period (around October), suggest that platypus experience high-energy demands during this phase of reproduction. Plasma glucocorticoid concentrations in females sampled during the lactation period (October-February) were relatively low, and similar to those in females sampled in the non-breeding, non-lactation period (March-June). The latter requires further investigation as results may have been influenced by sampling limitations.


Subject(s)
Glucocorticoids/blood , Platypus/blood , Animals , Fatty Acids, Nonesterified/blood , Fatty Acids, Nonesterified/metabolism , Female , Glucocorticoids/metabolism , Glucose/metabolism , Lactation , Male , Reproduction , Seasons , Time Factors
16.
Endoscopy ; 35(11): 951-6, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14606019

ABSTRACT

BACKGROUND AND STUDY AIMS: Although the reported diagnostic yield of push enteroscopy has been substantial in previous studies, its clinical impact has never been prospectively evaluated. The primary aim of this study was to prospectively determine the diagnostic and therapeutic impact of enteroscopy. In addition, the yield of new and clinically important findings was prospectively assessed. PATIENTS AND METHODS: Consecutive patients referred for enteroscopy were studied. The referring clinician completed a form indicating the working diagnosis, degree of diagnostic certainty, and the management plan had enteroscopy been unavailable. Diagnostic certainty was indicated on a scale of 1 = very unlikely (1 - 9 %) to 6 = certain (100 %). Following enteroscopy, the referring doctor completed another form indicating these features in the light of the enteroscopic findings. RESULTS: The study group comprised 77 patients referred for 79 push enteroscopies. There was a change in working diagnosis or management plan as a result of enteroscopy in 39/77 (51 %) patients. The working diagnosis and the management plan changed in 29/77 (38 %) and 34/77 (44 %), respectively, and the diagnostic certainty changed in a further 29 patients (38 %). There were clinically significant small-bowel findings in 16 (20 %) and new upper gastrointestinal findings in 16 (20 %), giving an overall diagnostic yield of 40 %. CONCLUSIONS: Enteroscopy has a significant impact on clinicians' working diagnoses and management plans.


Subject(s)
Endoscopy, Gastrointestinal/methods , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/therapy , Adult , Aged , Aged, 80 and over , Female , Humans , Intestine, Small , Male , Middle Aged , Professional Practice , Prospective Studies
17.
Qual Life Res ; 12(2): 177-88, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12639064

ABSTRACT

This study reports on the preliminary testing of a new measure designed for use alongside EQ-5D in evaluating outcomes in podiatry: the Podiatry Health Questionnaire (PHQ). Individuals aged 18 years or more, receiving podiatry services in clinic or domicilliary locations across four NHS Trusts in Yorkshire and Humberside UK took part in a questionnaire survey. Respondents reported high levels of problems on all six PHQ dimensions. Correlations suggested that the PHQ and EQ-5D were measuring distinct constructs. The levels on each dimension were well defined in terms of self-rated morbidity on the PHQ visual analogue scale (PHQvas) and the EQ-5Dvas, although PHQvas appeared to be slightly more sensitive to changes in health on the dimensions. There was a strong relationship between clinicians' Podiatry Clinical Score rating and reported symptoms for four out of six PHQ dimensions and PHQvas. The PHQ was able to distinguish respondents in terms of their self-reported morbidity in EQ-5D and in terms of their morbidity as assessed by clinicians. It is suggested that the respondent completed PHQ appears to be a useful new measure for assessing foot-related health. However, further investigation of the psychometric properties of the measure is required.


Subject(s)
Foot Diseases/therapy , Outcome Assessment, Health Care/methods , Podiatry/standards , Surveys and Questionnaires , Adolescent , Adult , Aged , Aged, 80 and over , Female , Foot Diseases/physiopathology , Health Services Research , Humans , Male , Middle Aged , Self Efficacy , Treatment Outcome , United Kingdom/epidemiology
19.
Environ Microbiol ; 4(4): 193-203, 2002 Apr.
Article in English | MEDLINE | ID: mdl-12010126

ABSTRACT

Methyl halide-degrading bacteria are a diverse group of organisms that are found in both terrestrial and marine environments. They potentially play an important role in mitigating ozone depletion resulting from methyl chloride and methyl bromide emissions. The first step in the pathway(s) of methyl halide degradation involves a methyltransferase and, recently, the presence of this pathway has been studied in a number of bacteria. This paper reviews the biochemistry and genetics of methyl halide utilization in the aerobic bacteria Methylobacterium chloromethanicum CM4T, Hyphomicrobium chloromethanicum CM2T, Aminobacter strain IMB-1 and Aminobacter strain CC495. These bacteria are able to use methyl halides as a sole source of carbon and energy, are all members of the alpha-Proteobacteria and were isolated from a variety of polluted and pristine terrestrial environments. An understanding of the genetics of these bacteria identified a unique gene (cmuA) involved in the degradation of methyl halides, which codes for a protein (CmuA) with unique methyltransferase and corrinoid functions. This unique functional gene, cmuA, is being used to develop molecular ecology techniques to examine the diversity and distribution of methyl halide-utilizing bacteria in the environment and hopefully to understand their role in methyl halide degradation in different environments. These techniques will also enable the detection of potentially novel methyl halide-degrading bacteria.


Subject(s)
Bacterial Proteins , Hydrocarbons, Brominated/metabolism , Hyphomicrobium/metabolism , Methyl Chloride/metabolism , Methylobacterium/metabolism , Amino Acid Sequence , Forecasting , Hyphomicrobium/genetics , Methylobacterium/genetics , Methyltransferases/genetics , Molecular Sequence Data , Sequence Homology, Amino Acid
20.
Appl Environ Microbiol ; 67(9): 3802-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11525970

ABSTRACT

Three particulate methane monooxygenase PCR primer sets (A189-A682, A189-A650, and A189-mb661) were investigated for their ability to assess methanotroph diversity in soils from three sites, i.e., heath, oak, and sitka, each of which was capable of oxidizing atmospheric concentrations of methane. Each PCR primer set was used to construct a library containing 50 clones from each soil type. The clones from each library were grouped by restriction fragment length polymorphism, and representatives from each group were sequenced and analyzed. Libraries constructed with the A189-A682 PCR primer set were dominated by amoA-related sequences or nonspecific PCR products with nonsense open reading frames. The primer set could not be used to assess methanotroph diversity in these soils. A new pmoA-specific primer, A650, was designed in this study. The A189-A650 primer set demonstrated distinct biases both in clone library analysis and when incorporated into denaturing gradient gel electrophoresis analysis. The A189-mb661 PCR primer set demonstrated the largest retrieval of methanotroph diversity of all of the primer sets. However, this primer set did not retrieve sequences linked with novel high-affinity methane oxidizers from the soil libraries, which were detected using the A189-A650 primer set. A combination of all three primer sets appears to be required to examine both methanotroph diversity and the presence of novel methane monooxygenase sequences.


Subject(s)
Methane/metabolism , Methylococcaceae/classification , Oxygenases/genetics , Polymerase Chain Reaction/methods , Soil Microbiology , DNA Primers , Denmark , Electrophoresis, Polyacrylamide Gel/methods , Methylococcaceae/genetics , Methylococcaceae/physiology , Molecular Sequence Data , Polymorphism, Restriction Fragment Length , Sequence Analysis, DNA , Trees
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