13 research outputs found

    Leafcutter ants adjust foraging behaviours when exposed to noise disturbance

    Get PDF
    We investigate the impact of anthropogenic noise on the foraging efficiency of leafcutter ants (Acromyrmex octospinosus) in a controlled laboratory experiment. Anthropogenic noise is a widespread, pervasive and increasing environmental pollutant and its negative impacts on animal fitness and behaviour have been well documented. Much of this evidence has come from studies concerning vertebrate species with very little evidence for terrestrial invertebrates, especially social living invertebrates. We compare movement speed, forage fragment size, and colony activity levels of ants exposed to intermittent elevated noise and in ambient noise conditions. We use intermittent and temporally unpredictable bursts of white noise produced from a vibration speaker to create the elevated noise profile. Ant movement speed increased under elevated noise conditions when travelling to collect forage material and when returning to the colony nest. The size of individually measured foraged material was significantly reduced under elevated noise conditions. Colony activity, the number of ants moving along the forage route, was not affected by elevated noise and was consistent throughout the foraging events. Increased foraging speed and smaller forage fragments suggests that the ants had to make more foraging trips over an extended period, which is likely to affect energy expenditure and increases exposure to predators. This is likely to have significant fitness impacts for the colony over time

    The Holy Grail: A road map for unlocking the climate record stored within Mars' polar layered deposits

    Get PDF
    In its polar layered deposits (PLD), Mars possesses a record of its recent climate, analogous to terrestrial ice sheets containing climate records on Earth. Each PLD is greater than 2 ​km thick and contains thousands of layers, each containing information on the climatic and atmospheric state during its deposition, creating a climate archive. With detailed measurements of layer composition, it may be possible to extract age, accumulation rates, atmospheric conditions, and surface activity at the time of deposition, among other important parameters; gaining the information would allow us to “read” the climate record. Because Mars has fewer complicating factors than Earth (e.g. oceans, biology, and human-modified climate), the planet offers a unique opportunity to study the history of a terrestrial planet’s climate, which in turn can teach us about our own planet and the thousands of terrestrial exoplanets waiting to be discovered. During a two-part workshop, the Keck Institute for Space Studies (KISS) hosted 38 Mars scientists and engineers who focused on determining the measurements needed to extract the climate record contained in the PLD. The group converged on four fundamental questions that must be answered with the goal of interpreting the climate record and finding its history based on the climate drivers. The group then proposed numerous measurements in order to answer these questions and detailed a sequence of missions and architecture to complete the measurements. In all, several missions are required, including an orbiter that can characterize the present climate and volatile reservoirs; a static reconnaissance lander capable of characterizing near surface atmospheric processes, annual accumulation, surface properties, and layer formation mechanism in the upper 50 ​cm of the PLD; a network of SmallSat landers focused on meteorology for ground truth of the low-altitude orbiter data; and finally, a second landed platform to access ~500 ​m of layers to measure layer variability through time. This mission architecture, with two landers, would meet the science goals and is designed to save costs compared to a single very capable landed mission. The rationale for this plan is presented below. In this paper we discuss numerous aspects, including our motivation, background of polar science, the climate science that drives polar layer formation, modeling of the atmosphere and climate to create hypotheses for what the layers mean, and terrestrial analogs to climatological studies. Finally, we present a list of measurements and missions required to answer the four major questions and read the climate record. 1. What are present and past fluxes of volatiles, dust, and other materials into and out of the polar regions? 2. How do orbital forcing and exchange with other reservoirs affect those fluxes? 3. What chemical and physical processes form and modify layers? 4. What is the timespan, completeness, and temporal resolution of the climate history recorded in the PLD

    The Holy Grail: A road map for unlocking the climate record stored within Mars' polar layered deposits

    Get PDF
    In its polar layered deposits (PLD), Mars possesses a record of its recent climate, analogous to terrestrial ice sheets containing climate records on Earth. Each PLD is greater than 2 ​km thick and contains thousands of layers, each containing information on the climatic and atmospheric state during its deposition, creating a climate archive. With detailed measurements of layer composition, it may be possible to extract age, accumulation rates, atmospheric conditions, and surface activity at the time of deposition, among other important parameters; gaining the information would allow us to “read” the climate record. Because Mars has fewer complicating factors than Earth (e.g. oceans, biology, and human-modified climate), the planet offers a unique opportunity to study the history of a terrestrial planet’s climate, which in turn can teach us about our own planet and the thousands of terrestrial exoplanets waiting to be discovered. During a two-part workshop, the Keck Institute for Space Studies (KISS) hosted 38 Mars scientists and engineers who focused on determining the measurements needed to extract the climate record contained in the PLD. The group converged on four fundamental questions that must be answered with the goal of interpreting the climate record and finding its history based on the climate drivers. The group then proposed numerous measurements in order to answer these questions and detailed a sequence of missions and architecture to complete the measurements. In all, several missions are required, including an orbiter that can characterize the present climate and volatile reservoirs; a static reconnaissance lander capable of characterizing near surface atmospheric processes, annual accumulation, surface properties, and layer formation mechanism in the upper 50 ​cm of the PLD; a network of SmallSat landers focused on meteorology for ground truth of the low-altitude orbiter data; and finally, a second landed platform to access ~500 ​m of layers to measure layer variability through time. This mission architecture, with two landers, would meet the science goals and is designed to save costs compared to a single very capable landed mission. The rationale for this plan is presented below. In this paper we discuss numerous aspects, including our motivation, background of polar science, the climate science that drives polar layer formation, modeling of the atmosphere and climate to create hypotheses for what the layers mean, and terrestrial analogs to climatological studies. Finally, we present a list of measurements and missions required to answer the four major questions and read the climate record. 1. What are present and past fluxes of volatiles, dust, and other materials into and out of the polar regions? 2. How do orbital forcing and exchange with other reservoirs affect those fluxes? 3. What chemical and physical processes form and modify layers? 4. What is the timespan, completeness, and temporal resolution of the climate history recorded in the PLD

    Unlocking the Climate Record Stored within Mars’ Polar Layered Deposits

    Get PDF
    In the icy beds of its polar layered deposits (PLD), Mars likely possesses a record of its recent climate history, analogous to terrestrial ice sheets that contain records of Earth's past climate. Both northern and southern PLDs store information on the climatic and atmospheric state during the deposition of each layer (WPs: Becerra et al.; Smith et al). Reading the climate record stored in these layers requires detailed measurements of layer composition, thickness, isotope variability, and near-surface atmospheric measurements. We identify four fundamental questions that must be answered in order to interpret this climate record and decipher the recent climatic history of Mars: 1. Fluxes: What are the present and past fluxes of volatiles, dust, and other materials into and out of the polar regions? 2. Forcings: How do orbital/axial forcing and exchange with other reservoirs affect those fluxes? 3. Layer Processes: What chemical and physical processes form and modify layers? 4. Record: What is the timespan, completeness, and temporal resolution of the climate history recorded in the PLD? In a peer reviewed report (1), we detailed a sequence of missions, instruments, and architecture needed to answer these questions. Here, we present the science drivers and a mission concept for a polar lander that would enable a future reading of the past few million years of the Martian climate record. The mission addresses as-yet-unachieved science goals of the current Decadal Survey and of MEPAG for obtaining a record of Mars climate and has parallel goals to the NEXSAG and ICE-SAG reports

    Open-label, multicentre, single-arm trial of monthly injections of depot buprenorphine in people with opioid dependence: protocol for the CoLAB study

    Get PDF
    Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. INTRODUCTION: Opioid agonist treatment is effective for opioid dependence and newer extended-release buprenorphine (BUP-XR) injections represent a significant development. The Community Long-Acting Buprenorphine (CoLAB) study aims to evaluate client outcomes among people with opioid dependence receiving 48 weeks of BUP-XR treatment, and examines the implementation of BUP-XR in diverse community healthcare settings in Australia. METHODS AND ANALYSIS: The CoLAB study is a prospective single-arm, multicentre, open-label trial of monthly BUP-XR injections in people with opioid dependence. Participants are being recruited from a network of general practitioner and specialist drug treatment services located in the states of New South Wales, Victoria and South Australia in Australia. Following a minimum 7 days on 8-32 mg of sublingual buprenorphine (±naloxone), participants will receive monthly subcutaneous BUP-XR injections administered by a healthcare practitioner at intervals of 28 days (-2/+14 days). The primary endpoint is participant retention in treatment at 48 weeks after treatment initiation. Secondary endpoints will evaluate dosing schedule variations, craving, withdrawal, substance use, health and well-being, and client-reported treatment experience. Qualitative and costing substudies will examine implementation barriers and facilitators at the client and provider level. ETHICS AND DISSEMINATION: The study has received ethics approval from the St Vincent\u27s Hospital Sydney Human Research Ethics Committee (Ref. HREC/18/SVH/221). The findings will be disseminated via publication in peer-reviewed journals, presentations at national and international scientific conferences, and in relevant community organisation publications and forums. TRIAL REGISTRATION NUMBER: NCT03809143 PROTOCOL IDENTIFIER: CoLAB1801, V.4.0 dated 01 August 2019

    Examining the cost and impact of dosing fees among clients in opioid agonist treatment: Results from a cross-sectional survey of Australian treatment clients

    Get PDF
    Introduction: Opioid agonist treatment (OAT) clients frequently bear costs associated with their treatment, including dosing fees. This study aimed to explore the financial and social impact of dosing fees upon clients. Methods: Cross-sectional survey of people who use opioids regularly (N = 402) between December 2017 and March 2018, conducted in Australia. Dosing fees were calculated and expressed as percentage of income, by OAT type. Consequences and strategies for difficulties making payments were examined as proportions. Results: A total of N = 360 participants had ever been in OAT and N = 245 participants currently engaged in OAT reported data on dosing fees, of them 53% (n = 129) reported paying dosing fees. Compared to clients with high levels of dosing supervision, those with moderate or low levels of supervision were more likely to pay dosing fees. The median 28-day dosing fee was AUD110(interquartilerangeAUD110 (interquartile range AUD80); median 28-day income was AUD1520(interquartilerangeAUD1520 (interquartile range AUD700). For those who paid dosing fees, the fee comprised \u3c10% of total monthly income for 70% of participants; however, 23% of participants paid fees comprising 10% to \u3c20%, and 7% of participants paid fees comprising 20% or more of monthly income. Among those that had ever been in OAT, 72% experienced difficulties in paying treatment costs; 36% left treatment earlier than intended and 25% had been excluded due to payment difficulties. Discussion and Conclusions: Negative consequences of treatment costs to clients, particularly dosing fees, are evident. These costs impact treatment access and retention that may negatively impact clients\u27 physical health, mental health and social wellbeing

    Study protocol the Continuing Care Project: A randomised controlled trial of a continuing care telephone intervention following residential substance dependence treatment

    Get PDF
    Background: A priority area in the field of substance dependence treatment is reducing the rates of relapse. Previous research has demonstrated that telephone delivered continuing care interventions are both clinically and cost effective when delivered as a component of outpatient treatment. This protocol describes a NSW Health funded study that assesses the effectiveness of delivering a telephone delivered continuing care intervention for people leaving residential substance treatment in Australia. Methods/design: All participants will be attending residential alcohol and other drug treatment provided by The Salvation Army or We Help Ourselves. The study will be conducted as a randomised controlled trial, where participants will be randomised to one of three treatment arms. The treatment arms will be: (i) 12-session continuing care telephone intervention; (ii) 4-session continuing care telephone intervention, or (iii) continuing care plan only. Baseline assessment batteries and development of the participants\u27 continuing care plan will be completed prior to participants being randomised to a treatment condition. Research staff blind to the treatment condition will complete follow-up assessments with participants at 3-months and 6-months after they have been discharged from their residential service. Discussion: This study will provide comprehensive data on the effect of delivering the continuing care intervention for people exiting residential alcohol and other drug treatment. If shown to be effective, this intervention can be disseminated to improve the rates of relapse among people leaving residential alcohol and other drug treatment

    Feasibility and preliminary results of a call centre delivered continuing care intervention following residential alcohol and other drug treatment

    No full text
    Introduction: To help reduce relapse rates following alcohol and other drug (AOD) treatment, continuing care interventions have been recommended. Previous continuing care interventions have incorporated telephone and face-to-face sessions to help promote participant engagement. The study was conducted as a randomised controlled feasibility study and examined a call centre delivered continuing care intervention for people leaving residential rehabilitation services. Methods: Participants were attending AOD residential treatment services in NSW, Australia (N = 154). Participants were randomised to either 12- or 4-sessions of continuing care. Follow up assessments were completed at 6-months. The primary outcomes were demand and implementation. Secondary outcomes were AOD use, mental health and physical health at 6-months. Results: Interest in continuing care was high, with 93% of participants approached reporting an interest in being involved. Of the participants who completed the consent and baseline procedures, 29% of people were contacted post residential treatment and randomised. For those people randomised, the average number of sessions completed was 2.78 (SD = 1.65) for the 4-session arm and 4.81 (SD = 4.46) for the 12-session arm. Fidelity to the treatment manual was high. Both treatment arms showed higher complete abstinence at 6-months compared to baseline (12-session OR 28.57 [2.3, 353.8]; 4-session OR 28.11 [3.6, 221.2]). Discussion and Conclusions: A major challenge associated with the call centre approach was re-engaging participants once they left the residential facility and delivering the planned dose of treatment. Further work is required to promote greater uptake of these protocols once people leave residential treatment
    corecore