Search Results (10)

Pesticide exposure has been cited as a key threat to insect pollinators. Notably, a diverse range of potential sublethal effects have been reported in bee species, with a particular focus on effects due to exposure to neonicotinoid insecticides. Here, a purpose-built thermal–visual arena was used in a series of pilot experiments to assess the potential impact of approximate sublethal concentrations of the next generation sulfoximine insecticide sulfoxaflor (5 and 50 ppb) and the neonicotinoid insecticides thiacloprid (500 ppb) and thiamethoxam (10 ppb), on the walking trajectory, navigation and learning abilities of the buff-tailed bumblebee (Bombus terrestris audax) when subjected to an aversive conditioning task. The results suggest that only thiamethoxam prevents forager bees from improving in key training parameters (speed and distanced travelled) within the thermal visual arena. Power law analyses further revealed that a speed–curvature power law, previously reported as being present in the walking trajectories of bumblebees, is potentially disrupted under thiamethoxam (10 ppb) exposure, but not under sulfoxaflor or thiacloprid exposure. The pilot assay described provides a novel tool with which to identify subtle sublethal pesticide impacts, and their potential causes, on forager bees, that current ecotoxicological tests are not designed to assess. Full article

The second messenger, cAMP has potent immunosuppressive and anti-inflammatory actions. These have been attributed, in part, to the ability of cAMP-induced signals to interfere with the function of the proinflammatory transcription factor Nuclear Factor-kappa B (NF-κB). However, the mechanisms underlying the modulation of NF-κB activity by cAMP remain unclear. Here we demonstrate an important role for cAMP-mediated increase in nuclear actin monomer levels in inhibiting NF-κB activity. Elevated cAMP or forced expression of a nuclear localised polymerisation defective actin mutant (NLS-Actin_R62D) inhibited basal and TNFα induced mRNA levels of NF-κB-dependent genes and NF-κB-dependent reporter gene activity. Elevated cAMP or NLS-Actin_R62D did not affect NF-κB nuclear translocation but did reduce total cellular and nuclear RelA/p65 levels. Preventing the cAMP-induced increase in nuclear actin monomer, either by expressing a nuclear localised active mutant of the actin polymerising protein mDIA, silencing components of the nuclear actin import complex IPO9 and CFL1 or overexpressing the nuclear export complex XPO6, rescued RelA/p65 levels and NF-κB reporter gene activity in forskolin-stimulated cells. Elevated cAMP or NLS-Actin_R62D reduced the half-life of RelA/p65, which was reversed by the proteasome inhibitor MG132. Accordingly, forskolin stimulated association of RelA/p65 with ubiquitin affinity beads, indicating increased ubiquitination of RelA/p65 or associated proteins. Taken together, our data demonstrate a novel mechanism underlying the anti-inflammatory effects of cAMP and highlight the important role played by nuclear actin in the regulation of inflammation. Full article

Throughout its 25-year history, the Five Domains Model for animal welfare assessment has been regularly updated to include at each stage the latest authenticated developments in animal welfare science thinking. The domains of the most up-to-date Model described here are: 1 Nutrition, 2 Physical Environment, 3 Health, 4 Behavioural Interactions and 5 Mental State. The first four domains focus attention on factors that give rise to specific negative or positive subjective experiences (affects), which contribute to the animal’s mental state, as evaluated in Domain 5. More specifically, the first three domains focus mainly on factors that disturb or disrupt particular features of the body’s internal stability. Each disturbed or disrupted feature generates sensory inputs which are processed by the brain to form specific negative affects, and these affects are associated with behaviours that act to restore the body’s internal stability. As each such behaviour is essential for the survival of the animal, the affects associated with them are collectively referred to as “survival-critical affects”. In contrast, Domain 4, now named Behavioural Interactions, focusses on evidence of animals consciously seeking specific goals when interacting behaviourally with (1) the environment, (2) other non-human animals and (3) as a new feature of the Model outlined here, humans. The associated affects, evaluated via Domain 5, are mainly generated by brain processing of sensory inputs elicited by external stimuli. The success of the animals’ behavioural attempts to achieve their chosen goals is reflected in whether the associated affects are negative or positive. Collectively referred to as “situation-related affects”, these outcomes are understood to contribute to animals’ perceptions of their external circumstances. These observations reveal a key distinction between the way survival-critical and situation-related affects influence animals’ aligned behaviours. The former mainly reflect compelling motivations to engage in genetically embedded behavioural responses, whereas the latter mainly involve conscious behavioural choices which are the hallmarks of agency. Finally, numerous examples of human–animal interactions and their attendant affects are described, and the qualitative grading of interactions that generate negative or positive affect is also illustrated. Full article

Consumption of L-Theanine (L-THE) has been associated with a sensation of relaxation, as well as a reduction of stress. However, these physiological responses have yet to be elucidated in humans where L-THE is compared alongside food or as a functional ingredient within the food matrix. The aim of this study was to determine the physiological responses of a single intake of a potential functional food product (mango sorbet) containing L-THE (ms-L-THE; 200 mgw/w) in comparison to a flavour and colour-matched placebo (ms). Eighteen healthy male participants were recruited in this randomised, double-blind, placebo-controlled trial. The participants were required to consume ms-L-THE or placebo and their blood pressure (BP) (systolic and diastolic), heart rate (HR), and heart rate variability (HRV) were monitored continuously over 90 minutes. Eleven males (age 27.7 ± 10.8 years) completed the study. Changes in area under the curve for systolic and diastolic blood pressure and HRV over the 90 minute observation period indicated no differences between the three conditions (all p > 0.05) or within individual groups (all p > 0.05). The values for heart rate were also not different in the placebo group (p = 0.996) and treatment group (p = 0.066), while there was a difference seen at the baseline (p = 0.003). Based on the findings of this study, L-THE incorporated in a food matrix (mango sorbet) demonstrated no reduction in BP or HR and showed no significant parasympathetic interaction as determined by HRV high-frequency band and low-frequency/high-frequency ratio. Further studies should be focussed towards the comparison of pure L-THE and incorporation within the food matrix to warrant recommendations of L-THE alongside food consumption. Full article

Background and Objectives: There is confusion as to which component of the Opuntia spp. cacti has demonstrated anti-hyperglycemic effects or anti-diabetic properties. It is important to clarify these health benefits due to the increasing need for prevention and treatment of chronic diseases. The aim of this review is to identify the effects of Opuntia spp. cacti consumption on biomedical measures; glucose and insulin with consideration of its’ components; fruit, leaf and combined or unidentified Opuntia spp. products. Materials and Methods: Prior to commencing the searches, this systematic review was registered with PROSPERO (CRD42018108765). Following the PRISMA 2009 guidelines, six electronic databases (Food Science and Technology Abstracts (EBSCO), Medline, Scopus, CINAHL, Web of Science and Cochrane) were searched for articles investigating the effect of Opuntia spp. consumption on glucose and insulin in humans. Results: Initially, 335 articles were sourced and filtered by exclusion criteria (human interventions, control trials and articles published in English) resulting in 20 relevant articles. The included studies were characterized by such plant components as fruit (n = 4), cladode (n = 12), and other Opuntia spp. products (n = 4), further separated by clinical populations (‘healthy’, hyperlipidemic, hypercholesterolemic, Type 2 Diabetes Mellitus). The findings of this review indicate variations in effects between cacti components and products. Cladode and select Opuntia spp. products predominately demonstrated significant reductions in serum glucose and insulin, indicating potential as a functional food candidate. Prickly Pear fruit was predominately reported to have no significant effects on glucose or insulin. The quality of evidence appeared to vary based on the type of Opuntia spp. product used. Studies that used specifically the fruit or cladode had high risk of bias, whereas studies which used combined Opuntia spp. products had a lower risk of bias. Numerous mechanisms of action were proposed where positive findings were reported, with emphasis on dualistic glucose-dependent and independent actions, however, mechanisms require further elucidation. Conclusion: Currently, there is a lack of evidence to support the recommendation of using Opuntia spp. fruit products as an alternative or complementary therapy in the reduction of risk or management of Type 2 Diabetes Mellitus. The Cladode does however show promise in potential glucose-lowering effects which warrant further investigation. Full article

Green tea catechins (GTCs) are secondary plant metabolites that have been associated with health benefits in human trials. As such, they have the potential to reduce cardiovascular disease (CVD) risk; however, results are not consistent. This systematic review of the published data assessed the putative effect of GTCs supplementation on anthropometric, blood pressure, and biochemical measures associated with CVD risk. It was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines exploring four major electronic databases (MEDLINE, Cochrane Library, Web of Science, and Scopus). Studies were included if they were published in peer-reviewed journals in English from 1990 until October 2015, and were human double-blind randomized and placebo-controlled trials (RCTs). From 122,428 articles initially identified, after two levels of screening, seven studies met the inclusion criteria. The review revealed consistent and significant (p ≤ 0.05) reductions in body mass index (BMI), blood pressure and plasma lipids; however, this effect would have been less if between-group effects had been considered. The current evidence base also has considerable methodological limitations due to suboptimal statistical methods used in data analyses. Future research efforts must aim to rectify this paucity of evidence with well-designed and well-reported prospective studies. Full article

Tea has been consumed for thousands of years and is an integral part of people’s daily routine, as an everyday drink and a therapeutic aid for health promotion. Consumption of tea has been linked to a sense of relaxation commonly associated with the content of the non-proteinogenic amino acid theanine, which is found within the tea leaves. The aim of this review article is to outline the current methods for synthesis, extraction and purification of theanine, as well as to examine its potential benefits related to human health. These include improvements in cognitive and immune function, cancer prevention, reduced cardiovascular risk and its potential usefulness as a functional food product. Full article

Operational assessment of forest structure is an on-going challenge for land managers, particularly over large, remote or inaccessible areas. Here, we present an easily adopted method for generating a continuous map of canopy height at a 30 m resolution, demonstrated over 2.9 million hectares of highly heterogeneous forest (canopy height 0–70 m) in Victoria, Australia. A two-stage approach was utilized where Airborne Laser Scanning (ALS) derived canopy height, captured over ~18% of the study area, was used to train a regression tree ensemble method; random forest. Predictor variables, which have a global coverage and are freely available, included Landsat Thematic Mapper (Tasselled Cap transformed), Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index time series, Shuttle Radar Topography Mission elevation data and other ancillary datasets. Reflectance variables were further processed to extract additional spatial and temporal contextual and textural variables. Modeled canopy height was validated following two approaches; (i) random sample cross validation; and (ii) with 108 inventory plots from outside the ALS capture extent. Both the cross validation and comparison with inventory data indicate canopy height can be estimated with a Root Mean Square Error (RMSE) of ≤ 31% (~5.6 m) at the 95th percentile confidence interval. Subtraction of the systematic component of model error, estimated from training data error residuals, rescaled canopy height values to more accurately represent the response variable distribution tails e.g., tall and short forest. Two further experiments were carried out to test the applicability and scalability of the presented method. Results suggest that (a) no improvement in canopy height estimation is achieved when models were constructed and validated for smaller geographic areas, suggesting there is no upper limit to model scalability; and (b) training data can be captured over a small percentage of the study area (~6%) if response and predictor variable variance is captured within the training cohort, however RMSE is higher than when compared to a stratified random sample. Full article

An automated laser rangefinding instrument was developed to characterize overstorey and understorey vegetation dynamics over time. Design criteria were based on information needs within the statewide forest monitoring program in Victoria, Australia. The ground-based monitoring instrument captures the key vegetation structural information needed to overcome ambiguity in the estimation of forest Leaf Area Index (LAI) from satellite sensors. The scanning lidar instrument was developed primarily from low cost, commercially accessible components. While the 635 nm wavelength lidar is not ideally suited to vegetation studies, there was an acceptable trade-off between cost and performance. Tests demonstrated reliable range estimates to live foliage up to a distance of 60 m during night-time operation. Given the instrument’s scan angle of 57.5 degrees zenith, the instrument is an effective tool for monitoring LAI in forest canopies up to a height of 30 m. An 18 month field trial of three co-located instruments showed consistent seasonal trends and mean LAI of between 1.32 to 1.56 and a temporal LAI variation of 8 to 17% relative to the mean. Full article

Mapping and monitoring forest extent is a common requirement of regional forest inventories and public land natural resource management, including in Australia. The state of Victoria, Australia, has approximately 7.2 million hectares of mostly forested public land, comprising ecosystems that present a diverse range of forest structures, composition and condition. In this paper, we evaluate the performance of the Random Forest (RF) classifier, an ensemble learning algorithm that has recently shown promise using multi-spectral satellite sensor imagery for large area feature classification. The RF algorithm was applied using selected Landsat Thematic Mapper (TM) imagery metrics and auxiliary terrain and climatic variables, while the reference data was manually extracted from systematically distributed plots of sample aerial photography and used for training (75%) and accuracy (25%) assessment. The RF algorithm yielded an overall accuracy of 96% and a Kappa statistic of 0.91 (confidence interval (CI) 0.909–0.919) for the forest/non-forest classification model, given a Kappa maximised binary threshold value of 0.5. The area under the receiver operating characteristic plot produced a score of 0.91, also indicating high model performance. The framework described in this study contributes to the operational deployment of a robust, but affordable, program, able to collate and process large volumes of multi-sourced data using open-source software for the production of consistent and accurate forest cover maps across the full spectrum of Victorian sclerophyll forest types. Full article