274 research outputs found

    Pre-clearing vegetation of the coastal lowlands of the Wet Tropics Bioregion, North Queensland

    Get PDF
    A pre-clearing vegetation map and digital coverage at approximately 1:50 000 scale for the coastal lowlands (up to about 200 m elevation) of the Wet Tropics Bioregion, North Queensland is presented. The study area covers about 508 000 ha from Cooktown, 420 km south almost to Townsville (latitude 15Β° 30’–18Β° 20’ longitude 144Β° 50’–146Β° 40’). Data sources included historical aerial photography, early surveyors’ plans, explorers’ journals, previous vegetation maps, and maps of soils and geology. The pre-clearing mapping was built around the remnant vegetation mapping of Stanton & Stanton (2005), and the vegetation classification of this latter work was adopted. Vegetation units were further classified into regional ecosystems compatible with the standard State-wide system used by Queensland government. The digital coverage is part of the current Queensland Herbarium regional ecosystem coverage (Queensland Herbarium and Wet Tropics Management Authority 2005). Coloured maps (1:100 000 scale) of the pre-clearing vegetation of the Herbert, Tully, Innisfail and Macalister/Daintree subregions are on an accompanying CD-ROM. An evaluation of vegetation loss through clearing on the coastal lowlands of the Wet Tropics revealed several nearextinct vegetation communities and regional ecosystems, and many others that are drastically reduced in area. Even ecosystems occurring on poorly drained lands have suffered a surprisingly high level of loss due to the effectiveness of drainage operations. Grassland ecosystems were found to be widespread on the Herbert and Tully floodplains, but are now close to extinction. The lowlands vegetation of the Wet Tropics that remains today continues to be fragmented and degraded despite the introduction of State-wide broad-scale tree-clearing laws in 1999, and the cessation of broadscale tree-clearing in December 2006

    Using lamb sales data to investigate associations between implementation of disease preventive practices and sheep flock performance

    Get PDF
    Although the UK is the largest lamb meat producer in Europe, there are limited data available on sheep flock performance and on how sheep farmers manage their flocks. The aims of this study were to gather evidence on the types of disease control practices implemented in sheep flocks, and to explore husbandry factors associated with flock productivity. A questionnaire focusing on farm characteristics, general husbandry and flock health management was carried out in 648 farms located in the UK over summer 2016. Abattoir sales data (lamb sales over 12 months) was compared with the number of breeding ewes on farm to estimate flock productivity (number of lambs sold for meat per 100 ewes per farm per year). Results of a multivariable linear regression model, conducted on 615 farms with complete data, indicated that farms vaccinating ewes against abortion and clostridial agents and administering a group 4/5 anthelmintic to ewes (as recommended by the Sustainable Control of Parasites in Sheep Initiative) during quarantining had a greater flock productivity than farms not implementing these actions (

    Non-destructive Assessment of Quality and Yield for Grass-Breeding

    Get PDF
    Selection of cultivars has, until now, been based mainly on dry matter (DM) yields because of the high costs of sampling and chemical analysis. Imaging spectroscopy could reduce costs by limiting sampling and harvesting of individual plots to reference samples (Schut et al., accepted). In this study, the prediction accuracy of DM yields and chemical composition with imaging spectroscopy is evaluated for cultivar selection purposes

    A quantitative PCR method to quantify ruminant DNA in porcine crude heparin

    Get PDF
    Heparin is a well-known glycosaminoglycan extracted from porcine intestines. Increased vigilance for transmissible spongiform encephalopathy in animal-derived pharmaceuticals requires methods to prevent the introduction of heparin from ruminants into the supply chain. The sensitivity, specificity, and precision of the quantitative polymerase chain reaction (PCR) make it a superior analytical platform for screening heparin raw material for bovine-, ovine-, and caprine-derived material. A quantitative PCR probe and primer set homologous to the ruminant Bov-A2 short interspersed nuclear element (SINE) locus (Mendoza-Romero et al. J. Food Prot. 67:550–554, 2004) demonstrated nearly equivalent affinities for bovine, ovine, and caprine DNA targets, while exhibiting no cross-reactivity with porcine DNA in the quantitative PCR method. A second PCR primer and probe set, specific for the porcine PRE1 SINE sequence, was also developed to quantify the background porcine DNA level. DNA extraction and purification was not necessary for analysis of the raw heparin samples, although digestion of the sample with heparinase was employed. The method exhibits a quantitation range of 0.3–3,000Β ppm ruminant DNA in heparin. Validation parameters of the method included accuracy, repeatability, precision, specificity, range, quantitation limit, and linearity

    Identification of cross reactive T cell responses in adenovirus based COVID 19 vaccines

    Get PDF
    Vaccination has proven to be a valuable tool to combat SARS-CoV-2. However, reports of rare adverse reactions such as thrombosis/thrombocytopenia syndrome after ChAdOx1 nCoV-19 vaccination have caused scientific, public and media concern. ChAdOx1 was vectorised from the Y25 chimpanzee adenovirus, which was selected due to low human seroprevalence to circumvent pre-existing immunity. In this study, we aimed to explore patterns of T-cell activation after SARS-CoV-2 COVID-19 vaccine exposure in vitro using PBMCs collected from pre-pandemic ChAdOx1 nCoV-19 naΓ―ve healthy donors (HDs), and ChAdOx1 nCoV-19 and Pfizer vaccinated controls. PBMCs were assessed for T-cell proliferation using the lymphocyte transformation test (LTT) following exposure to SARS-CoV-2 COVID-19 vaccines. Cytokine analysis was performed via intracellular cytokine staining, ELISpot assay and LEGENDplex immunoassays. T-cell assays performed in pre-pandemic vaccine naΓ―ve HDs, revealed widespread lymphocyte stimulation after exposure to ChAdOx1 nCoV-19 (95%), ChAdOx-spike (90%) and the Ad26.COV2. S vaccine, but not on exposure to the BNT162b2 vaccine. ICS analysis demonstrated that CD4+ CD45RO+ memory T-cells are activated by ChAdOx1 nCoV-19 in vaccine naΓ―ve HDs. Cytometric immunoassays showed ChAdOx1 nCoV-19 exposure was associated with the release of proinflammatory and cytotoxic molecules, such as IFN-Ξ³, IL-6, perforin, granzyme B and FasL. These studies demonstrate a ubiquitous T-cell response to ChAdOx1 nCoV-19 and Ad26.COV2. S in HDs recruited prior to the SARS-CoV-2 pandemic, with T-cell stimulation also identified in vaccinated controls. This may be due to underlying T-cell cross-reactivity with prevalent human adenoviruses and further study will be needed to identify T-cell epitopes involved

    Cognitive performance in light current users and ex-users of ecstasy (MDMA) and controls

    Get PDF
    Previous research has shown that heavy users of ecstasy may suffer impaired cognitive functioning, and the present study set out to investigate whether such impairment might also be found in light users or ex-users of ecstasy. Sixty subjects, comprising 20 current light users, 20 ex-users, and 20 non-users of ecstasy, were tested on an extensive battery of cognitive tests. Current light users of ecstasy achieved significantly lower scores on the overall cognitive test battery than did the non-users (p=0.011), though there were no significant differences on any individual subtests. However, the scores obtained by the ex-users of ecstasy did not differ significantly from those of the non-users. It was concluded that current light users of ecstasy show a small but significant cognitive impairment, but that no such impairment is detectable in ex-users who had abstained from the drug for at least 6 months

    Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents : an in vitro study

    Get PDF
    Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state

    Statistical tools for transgene copy number estimation based on real-time PCR

    Get PDF
    Background As compared with traditional transgene copy number detection technologies such as Southern blot analysis, real-time PCR provides a fast, inexpensive and high-throughput alternative. However, the real-time PCR based transgene copy number estimation tends to be ambiguous and subjective stemming from the lack of proper statistical analysis and data quality control to render a reliable estimation of copy number with a prediction value. Despite the recent progresses in statistical analysis of real-time PCR, few publications have integrated these advancements in real-time PCR based transgene copy number determination. Results Three experimental designs and four data quality control integrated statistical models are presented. For the first method, external calibration curves are established for the transgene based on serially-diluted templates. The Ct number from a control transgenic event and putative transgenic event are compared to derive the transgene copy number or zygosity estimation. Simple linear regression and two group T-test procedures were combined to model the data from this design. For the second experimental design, standard curves were generated for both an internal reference gene and the transgene, and the copy number of transgene was compared with that of internal reference gene. Multiple regression models and ANOVA models can be employed to analyze the data and perform quality control for this approach. In the third experimental design, transgene copy number is compared with reference gene without a standard curve, but rather, is based directly on fluorescence data. Two different multiple regression models were proposed to analyze the data based on two different approaches of amplification efficiency integration. Our results highlight the importance of proper statistical treatment and quality control integration in real-time PCR-based transgene copy number determination. Conclusion These statistical methods allow the real-time PCR-based transgene copy number estimation to be more reliable and precise with a proper statistical estimation. Proper confidence intervals are necessary for unambiguous prediction of trangene copy number. The four different statistical methods are compared for their advantages and disadvantages. Moreover, the statistical methods can also be applied for other real-time PCR-based quantification assays including transfection efficiency analysis and pathogen quantification

    Quantification of Trace-Level DNA by Real-Time Whole Genome Amplification

    Get PDF
    Quantification of trace amounts of DNA is a challenge in analytical applications where the concentration of a target DNA is very low or only limited amounts of samples are available for analysis. PCR-based methods including real-time PCR are highly sensitive and widely used for quantification of low-level DNA samples. However, ordinary PCR methods require at least one copy of a specific gene sequence for amplification and may not work for a sub-genomic amount of DNA. We suggest a real-time whole genome amplification method adopting the degenerate oligonucleotide primed PCR (DOP-PCR) for quantification of sub-genomic amounts of DNA. This approach enabled quantification of sub-picogram amounts of DNA independently of their sequences. When the method was applied to the human placental DNA of which amount was accurately determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES), an accurate and stable quantification capability for DNA samples ranging from 80 fg to 8 ng was obtained. In blind tests of laboratory-prepared DNA samples, measurement accuracies of 7.4%, βˆ’2.1%, and βˆ’13.9% with analytical precisions around 15% were achieved for 400-pg, 4-pg, and 400-fg DNA samples, respectively. A similar quantification capability was also observed for other DNA species from calf, E. coli, and lambda phage. Therefore, when provided with an appropriate standard DNA, the suggested real-time DOP-PCR method can be used as a universal method for quantification of trace amounts of DNA
    • …
    corecore