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1.
J Mammal ; 104(5): 929-940, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37800099

ABSTRACT

Decommissioning the dingo barrier fence has been suggested to reduce destructive dingo control and encourage a free transfer of biota between environments in Australia. Yet the potential impacts that over a century of predator exclusion might have had on the population dynamics and developmental biology of prey populations has not been assessed. We here combine demographic data and both linear and geometric morphometrics to assess differences in populations among 166 red kangaroos (Osphranter rufus)-a primary prey species of the dingo-from two isolated populations on either side of the fence. We also quantified the differences in aboveground vegetation biomass for the last 10 years on either side of the fence. We found that the age structure and growth patterns, but not cranial shape, differed between the two kangaroo populations. In the population living with a higher density of dingoes, there were relatively fewer females and juveniles. These individuals were larger for a given age, despite what seems to be lower vegetation biomass. However, how much of this biomass represented kangaroo forage is uncertain and requires further on-site assessments. We also identified unexpected differences in the ontogenetic trajectories in relative pes length between the sexes for the whole sample, possibly associated with male competition or differential weight-bearing mechanics. We discuss potential mechanisms behind our findings and suggest that the impacts of contrasting predation pressures across the fence, for red kangaroos and other species, merit further investigation.

2.
Environ Entomol ; 50(4): 762-780, 2021 08 12.
Article in English | MEDLINE | ID: mdl-33860802

ABSTRACT

Following the introduction of cattle, exotic dung beetles (Coleoptera: Aphodiidae, Geotrupidae, Scarabaeidae) were imported into the Antipodes (Australia and New Zealand) and North America (primarily the United States) to accelerate the degradation of cattle dung on pastures. The history of dung beetle introductions between the two regions is similar but has not previously been assessed: this is important as new introductions are continuing in the regions. Here, we review these introduction programs, report on their current status, and discuss methodological advances. In doing so, we examine the accidental introduction of exotic (i.e., adventive) species and the contribution of both deliberately introduced and adventive species to endemic dung beetle faunas. Further, we provide a list of pest and parasite species whose populations can be reduced by dung beetle activity. We also identify a combined total of 37 introduced and 47 adventive dung beetle species that have become established in the Antipodes and North America, with exotic species dominating dung beetle assemblages from pasture habitats. Climatic and edaphic matches, the size of founding populations, abiotic and biotic stressors, and the time of year when releases are made are all critical determinants that affect the success of dung beetle introduction programs. Finally, we discuss opportunities, plus the risks and challenges associated with dung beetle introductions. We hope that this review will aid in the success of future introduction programs, either to enhance ecosystem services in areas that they are needed, or potentially to reestablish native species in regions where they have been extirpated.


Subject(s)
Coleoptera , Animals , Cattle , Ecosystem , Feces , New Zealand , North America
3.
PeerJ ; 8: e9872, 2020.
Article in English | MEDLINE | ID: mdl-33062417

ABSTRACT

Dung beetle introduction programmes were designed to accelerate exotic livestock dung degradation and to control dung breeding pestiferous flies and livestock parasites. The introduction programmes provided exotic dung beetle species with an opportunity to cross natural barriers and spread beyond their native range. There are no reports that explain what probable adaptation mechanisms enable particular dung beetle species to be the most successful invader. Here we identify the morphological, biological, physiological, ecological and behavioural attributes of the four most widespread and successful dung beetle species in introduced areas on a global scale in relation to the assumption that these species are different from other exotic and native dung beetles. We have recognised Digitonthophagus gazella (Fabricius), Onthophagus taurus (Schreber), Euoniticellus intermedius (Reiche) and Aphodius fimetarius (Linnaeus) as the most successful invaders based on their spread, predominance, distribution range and the reports of invasion. Each of these four species has different natural history traits that increase their fitness making them successful invaders. D. gazella has high fecundity and spreading ability, can instantly locate and colonise fresh and nutritious dung, and has a broad thermal window. O. taurus has morphological plasticity, high fecundity, high brood survival rate due to bi-parenting, and is adapted to extreme thermal and moisture conditions. E. intermedius has remnant-dung feeding abilities, a wide thermal window, functioning best at upper-temperature levels, and successful breeding and survival abilities at extremely low soil moisture conditions. A. fimetarius is small-sized, has high breeding and dispersal abilities, and is adapted to lower thermal and upper moisture extremes and variable soil conditions. Discussed here are perspectives on adaptive attributes of dung beetle species that are important to consider during their selection for redistributions. We have elaborated on the fitness and success characteristics of the four species individually. Further, we recommend a prior-introduction baseline monitoring of native dung beetle assemblages so as to evaluate the future impact of exotic dung beetle introductions on the recipient ecosystem.

4.
Environ Sci Pollut Res Int ; 27(17): 21702-21715, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32279265

ABSTRACT

The exponential growth in the use of motor vehicles is a key contributor to freshwater degradation. Current remediation techniques require prohibitively expensive contaminant treatment and extraction. Biochar represents an inexpensive option to ameliorate contaminants from motorway runoff. Biochar from Norway spruce (Picea abies (L.) Karst.) was produced under fast pyrolysis-gasification (450-500 °C for 90 s) and amended with wood ash and basaltic rock dust to evaluate sorption of Pb, Cu, Zn and Cd. The column study, designed to mimic field conditions, confirmed that unamended biochar can bind contaminants for short periods, but that the addition of amendments, particularly wood ash, significantly improves contaminant removal. Wood ash-amended biochar removed 98-100% of all contaminants during the study, driven by pH (r = 0.73-0.74; p < 0.01 dependent on metal species) and phosphorus levels causing precipitation (r = 0.47-0.59; p < 0.01, dependent on metal species). The contaminants' progression through the biochar subsections in the column indicated that increasing the thickness of the biochar layer increased contaminant residence time and removal.


Subject(s)
Cadmium , Soil Pollutants/analysis , Charcoal , Copper , Lead , Norway , Soil , Zinc
5.
Anal Chem ; 90(9): 5664-5670, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29629760

ABSTRACT

The high sensitivity of proton transfer reaction-mass spectrometry (PTR-MS) makes it a suitable analytical tool for detecting trace compounds. Its specificity is primarily determined by the accuracy of identifying the m/ z of the product ions specific to a particular compound. However, specificity can be enhanced by changing the product ions (concentrations and types) through modifying the reduced electric field. For current PTR-MS systems, this is not possible for trace compounds that would only be present in the reaction chamber of a PTR-MS for a short time (seconds). For such circumstances, it is necessary to change the reduce electric field swiftly if specificity enhancements are to be achieved. In this paper we demonstrate such a novel approach, which permits any compound that may only be present in the drift tube for seconds to be thoroughly investigated. Specifically, we have developed hardware and software which permits the reaction region's voltages to be rapidly switched at a frequency of 0.1-5 Hz. We show how this technique can be used to provide a higher confidence in the identification of compounds than is possible by keeping to one reduced electric field value through illustrating the detection of explosives. Although demonstrated for homeland security applications, this new technique has applications in other analytical areas and disciplines where rapid changes in a compound's concentration can occur, for example, in the Earth's atmosphere, plant emissions and in breath. Importantly, this adaptation provides a method for improved selectivity without expensive instrumental changes or the need for high mass resolution instruments.

6.
BMJ ; 357: j2035, 2017 04 28.
Article in English | MEDLINE | ID: mdl-28455311
7.
Anal Chem ; 88(21): 10624-10630, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27715015

ABSTRACT

A key issue with any analytical system based on mass spectrometry with no initial separation of compounds is to have a high level of confidence in chemical assignment. This is particularly true for areas of security, such as airports, and recent terrorist attacks have highlighted the need for reliable analytical instrumentation. Proton transfer reaction mass spectrometry is a useful technology for these purposes because the chances of false positives are small owing to the use of a mass spectrometric analysis. However, the detection of an ion at a given m/z for an explosive does not guarantee that that explosive is present. There is still some ambiguity associated with any chemical assignment owing to the presence of isobaric compounds and, depending on mass resolution, ions with the same nominal m/z. In this article we describe how for the first time the use of a radio frequency ion-funnel (RFIF) in the reaction region (drift tube) of a proton transfer reaction-time-of-flight-mass spectrometer (PTR-ToF-MS) can be used to enhance specificity by manipulating the ion-molecule chemistry through collisional induced processes. Results for trinitrotoluene, dinitrotoluenes, and nitrotoluenes are presented to demonstrate the advantages of this new RFIF-PTR-ToF-MS for analytical chemical purposes.

8.
Mar Environ Res ; 99: 188-97, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25016938

ABSTRACT

Previous research has alluded to the potential of metals being absorbed by fish after ingesting fishing hooks, which may have adverse effects on fish health and the organisms that consume them. Subsequently, this study aimed to quantify the potential of mulloway (Argyrosomus japonicus) to absorb metals during the decay of ingested nickel-plated carbon-steel hooks. Twenty-five treatment fish were allowed to ingest nickel-plated carbon-steel hooks during angling and then monitored with 25 controls (untreated fish) for up to 42 days for hook ejection and mortality. Blood, liver and muscle samples were collected from treatment, control and 14 wild-caught individuals to determine the concentrations of chromium, cobalt, copper, iron, manganese and nickel. The results showed that increased oxidation influenced hook ejection, and that hook-ingested fish had significantly elevated concentrations of nickel in their liver and blood, but not muscle. This research has shown that there is an avenue for metal absorption from ingested hooks.


Subject(s)
Absorption, Physiological/physiology , Metals, Heavy/pharmacokinetics , Perciformes/metabolism , Animals , Fisheries/instrumentation , Linear Models , Liver/metabolism , Mass Spectrometry , Metals, Heavy/blood , Metals, Heavy/metabolism , Muscle, Skeletal/metabolism , Nickel , Oxidation-Reduction , Steel
9.
Clin Med (Lond) ; 14(1): 86-7, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24532755

ABSTRACT

We present here a case of cannabinoid hyperemesis syndrome (CHS), which is an under-recognised disorder presenting in chronic abusers of cannabis typically as cyclical vomiting relieved by frequent hot baths. Increased awareness of CHS allows for earlier recognition by emergency departments, leading to prompter treatment and the prevention of future recurrence through cannabis cessation.


Subject(s)
Abdominal Pain/etiology , Hydrotherapy , Marijuana Abuse/complications , Vomiting/etiology , Vomiting/therapy , Abdominal Pain/therapy , Adult , Hot Temperature/therapeutic use , Humans , Male , Syndrome
11.
Liver Int ; 33(8): 1266-70, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23750872

ABSTRACT

BACKGROUND: Though possession of androgenic anabolic steroids (AAS) is illegal, non-prescription use of AAS persists. METHODS: We describe two Caucasian males (aged 25 and 45 years) with cholestatic hepatitis following ingestion of the dietary supplement Mass-Drol ('Celtic Dragon') containing the AAS 2α-17α-dimethyl-etiocholan-3-one,17ß-ol. RESULTS: Despite substantial hyperbilirubinaemia peak gamma-glutamyl transferase (GGT) remained normal. Besides 'bland' intralobular cholestasis, liver biopsy in both found deficiency of canalicular expression of ectoenzymes as seen in ATP8B1 disease. In the older patient, bile salt export pump marking (encoded by ABCB11) was focally diminished. We hypothesized that AAS had either induced inhibition of normal ATP8B1/ABCB11 expression or triggered initial episodes of benign recurrent intrahepatic cholestasis (BRIC) type 1/or 2. On sequencing, ATP8B1 was normal in both patients although the younger was heterozygous for the c.2093G>A mutation in ABCB11, a polymorphism previously encountered in drug-induced liver injury. CONCLUSION: AAS marketed as dietary supplements continue to cause hepatotoxicity in the UK; underlying mechanisms may include unmasking of genetic cholestatic syndromes.


Subject(s)
ATP-Binding Cassette Transporters/genetics , Adenosine Triphosphatases/genetics , Anabolic Agents/adverse effects , Androgens/adverse effects , Chemical and Drug Induced Liver Injury/genetics , Cholestasis, Intrahepatic/chemically induced , Cholestasis, Intrahepatic/genetics , Dietary Supplements/adverse effects , Mutation , ATP Binding Cassette Transporter, Subfamily B, Member 11 , Adult , Biomarkers/blood , Chemical and Drug Induced Liver Injury/blood , Cholestasis, Intrahepatic/blood , DNA Mutational Analysis , Genetic Predisposition to Disease , Humans , Hyperbilirubinemia/chemically induced , Hyperbilirubinemia/genetics , Male , Middle Aged , Phenotype , Risk Factors , gamma-Glutamyltransferase/blood
12.
Gut ; 59(5): 666-89, 2010 May.
Article in English | MEDLINE | ID: mdl-20427401

ABSTRACT

The British Society of Gastroenterology (BSG) and the Association of Coloproctology for Great Britain and Ireland (ACPGBI) commissioned this update of the 2002 guidance. The aim, as before, is to provide guidance on the appropriateness, method and frequency of screening for people at moderate and high risk from colorectal cancer. This guidance provides some new recommendations for those with inflammatory bowel disease and for those at moderate risk resulting from a family history of colorectal cancer. In other areas guidance is relatively unchanged, but the recent literature was reviewed and is included where appropriate.


Subject(s)
Colorectal Neoplasms/diagnosis , Early Detection of Cancer/methods , Acromegaly/complications , Adenoma/diagnosis , Anastomosis, Surgical/adverse effects , Colon, Sigmoid/surgery , Colonoscopy/methods , Colonoscopy/standards , Colorectal Neoplasms/etiology , Colorectal Neoplasms/surgery , Early Detection of Cancer/standards , Evidence-Based Medicine/methods , Humans , Inflammatory Bowel Diseases/complications , Neoplastic Syndromes, Hereditary/diagnosis , Population Surveillance/methods , State Medicine/standards , Ureter/surgery
13.
Dis Aquat Organ ; 81(2): 127-34, 2008 Aug 27.
Article in English | MEDLINE | ID: mdl-18924377

ABSTRACT

We completed 2 experiments to quantify the mortality and physical damage (fin, blood and scale loss) of angled dusky flathead Platycephalus fuscus during a live weigh-in tournament (Expt 1) and after being immediately released by anglers (Expt 2). In each experiment, 84 and 79 angled P. fuscus were placed into up to 6 replicate tanks and, along with appropriate numbers of controls, monitored for mortalities over 5 d. Five and 7 of the angled fish died within 12 h, providing mortalities of 3.6 and 8.9% in Expts 1 and 2, respectively. One control fish died, which was attributed to an incorrectly inserted tag. None of the continuous or categorical variables collected during angling and subsequent release, or the experimental design, could explain the few observed mortalities to treatment fish. However, knotted large-mesh landing nets caused significantly greater fin damage than knotless fine-mesh designs in both experiments (p < 0.05). Furthermore, although water quality had no measured impact on the confined fish, the samples taken from anglers' live wells (mostly for Expt 1) were significantly poorer than the environment from which the fish were caught (p < 0.05). These latter differences may have had a cumulative negative impact on fish that manifested as the observed deaths. Simple changes to the post-capture handling of P. fuscus, involving appropriate landing nets and live wells, should reduce some angling impacts on this species.


Subject(s)
Fish Diseases/mortality , Fishes , Foreign Bodies/veterinary , Animals , Ecosystem , Risk Factors , Stress, Physiological
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