101 research outputs found
Chronic morphine reduces surface expression of δ-opioid receptors in subregions of rostral striatum
The delta opioid receptor (DOPr), whilst not the primary target of clinically used opioids, is involved in development of opioid tolerance and addiction. There is growing evidence that DOPr trafficking is involved in drug addiction, e.g., a range of studies have shown increased plasma membrane DOPr insertion during chronic treatment with opioids. The present study used a transgenic mouse model in which the C-terminal of the DOPr is tagged with enhanced-green fluorescence protein to examine the effects of chronic morphine treatment on surface membrane expression in striatal cholinergic interneurons that are implicated in motivated learning following both chronic morphine and morphine sensitization treatment schedules in male mice. A sex difference was noted throughout the anterior striatum, which was most prominent in the nucleus accumbens core region. Incontrast with previous studies in other neurons, chronic exposure to a high dose of morphine for 6 days had no effect, or slightly decreased (anterior dorsolateral striatum) surface DOPr expression. A morphine sensitization schedule produced similar results with a significant decrease in surface DOPr expression in nucleus accumbens shell. These results suggest that chronic morphine and morphine sensitisation treatment may have effects on instrumental reward-seeking behaviours and learning processes related to drug addiction, via effects on striatal DOPr function.NHMRC Grants: 1045964 & 108925
Chronic morphine reduces surface expression of δ-opioid receptors in subregions of rostral striatum
The delta opioid receptor (DOPr), whilst not the primary target of clinically used opioids, is involved in development of opioid tolerance and addiction. There is growing evidence that DOPr trafficking is involved in drug addiction, e.g., a range of studies have shown increased plasma membrane DOPr insertion during chronic treatment with opioids. The present study used a transgenic mouse model in which the C-terminal of the DOPr is tagged with enhanced-green fluorescence protein to examine the effects of chronic morphine treatment on surface membrane expression in striatal cholinergic interneurons that are implicated in motivated learning following both chronic morphine and morphine sensitization treatment schedules in male mice. A sex difference was noted throughout the anterior striatum, which was most prominent in the nucleus accumbens core region. Incontrast with previous studies in other neurons, chronic exposure to a high dose of morphine for 6 days had no effect, or slightly decreased (anterior dorsolateral striatum) surface DOPr expression. A morphine sensitization schedule produced similar results with a significant decrease in surface DOPr expression in nucleus accumbens shell. These results suggest that chronic morphine and morphine sensitisation treatment may have effects on instrumental reward-seeking behaviours and learning processes related to drug addiction, via effects on striatal DOPr function.NHMRC Grants: 1045964 & 108925
Local Inhomogeneity in Asymmetric Simple Exclusion Processes with Extended Objects
Totally asymmetric simple exclusion processes (TASEP) with particles which
occupy more than one lattice site and with a local inhomogeneity far away from
the boundaries are investigated. These non-equilibrium processes are relevant
for the understanding of many biological and chemical phenomena. The
steady-state phase diagrams, currents, and bulk densities are calculated using
a simple approximate theory and extensive Monte Carlo computer simulations. It
is found that the phase diagram for TASEP with a local inhomogeneity is
qualitatively similar to homogeneous models, although the phase boundaries are
significantly shifted. The complex dynamics is discussed in terms of
domain-wall theory for driven lattice systems.Comment: 11 pages, 5 figure
Agents of change in bushfire recovery: young people's acts of citizenship in a youth-focused, animal-welfare and environmental program
Bushfires and natural hazard disasters have a significant impact on young people and risk reduction strategies have largely focused on addressing their vulnerability and mitigating the effects of trauma. In the 21st century practitioners, researchers and the Sendai Framework for Disaster Risk Reduction 2015–2030, are calling for young people to become ‘agents of change’ in disaster management. When young people are included in disaster management there are benefits for themselves, their peers, community and the environment at local, state and national levels. Our program, with young people affected by Australia's 2019–2020 Black Summer bushfires, highlighted their frustrations at the limited opportunities to be actively involved in relief and recovery, and their concerns about the combined impact of the climate crisis and bushfires. Their focus aligns with a shift in young people's acts of citizenship and community involvement as they seek opportunities to engage with issues that impact them and their future. Young people's engagement in a youth-focused, empowerment-oriented, animal-welfare program in the Australian state of Victoria, The Activators, demonstrates how young people join the dots between bushfire recovery, the climate crisis and environmental issues to undertake local acts of citizenship. This article focuses on young people's experiences and a young person's powerful narrative of Loss, urgency, grief and loneliness. We draw on the challenges and opportunities of young people's individual and collective experience of the program. Our analysis investigates how a programmatic intervention empowered young people to become agents of change through acts of citizenship in their local communities. Adopting similar approaches would enable young people to be actively involved in disaster, prevention, preparedness, response and recovery, across all levels of planning and community engagement
Understanding uncertainty in temperature effects on vector-borne disease: A Bayesian approach
Extrinsic environmental factors influence the distribution and population
dynamics of many organisms, including insects that are of concern for human
health and agriculture. This is particularly true for vector-borne infectious
diseases, like malaria, which is a major source of morbidity and mortality in
humans. Understanding the mechanistic links between environment and population
processes for these diseases is key to predicting the consequences of climate
change on transmission and for developing effective interventions. An important
measure of the intensity of disease transmission is the reproductive number
. However, understanding the mechanisms linking and temperature, an
environmental factor driving disease risk, can be challenging because the data
available for parameterization are often poor. To address this we show how a
Bayesian approach can help identify critical uncertainties in components of
and how this uncertainty is propagated into the estimate of . Most
notably, we find that different parameters dominate the uncertainty at
different temperature regimes: bite rate from 15-25 C; fecundity across
all temperatures, but especially 25-32 C; mortality from
20-30 C; parasite development rate at 15-16C and again at
33-35C. Focusing empirical studies on these parameters and
corresponding temperature ranges would be the most efficient way to improve
estimates of . While we focus on malaria, our methods apply to improving
process-based models more generally, including epidemiological, physiological
niche, and species distribution models.Comment: 27 pages, including 1 table and 3 figure
Team-Based Integrated Knowledge Translation for Enhancing Quality of Life in Long-term Care Settings: A Multi-method, Multi-sectoral Research Design
Multi-sectoral, interdisciplinary health research is increasingly recognizing integrated knowledge translation (iKT) as essential. It is characterized by diverse research partnerships, and iterative knowledge engagement, translation processes and democratized knowledge production. This paper reviews the methodological complexity and decision-making of a large iKT project called Seniors - Adding Life to Years (SALTY), designed to generate evidence to improve late life in long-term care (LTC) settings across Canada. We discuss our approach to iKT by reviewing iterative processes of team development and knowledge engagement within the LTC sector. We conclude with a brief discussion of the important opportunities, challenges, and implications these processes have for LTC research, and the sector more broadly
A case control study of environmental and occupational exposures associated with methicillin resistant Staphylococcus aureus nasal carriage in patients admitted to a rural tertiary care hospital in a high density swine region
Background: Distinct strains of methicillin resistant Staphylococcus aureus (MRSA) have been identified on livestock
and livestock workers. Industrial food animal production may be an important environmental reservoir for human
carriage of these pathogenic bacteria. The objective of this study was to investigate environmental and
occupational exposures associated with nasal carriage of MRSA in patients hospitalized at Vidant Medical Center,
a tertiary hospital serving a region with intensive livestock production in eastern North Carolina.
Methods: MRSA nasal carriage was identified via nasal swabs collected within 24 hours of hospital admission.
MRSA carriers (cases) were gender and age matched to non-carriers (controls). Participants were interviewed about
recent environmental and occupational exposures. Home addresses were geocoded and publicly available data
were used to estimate the density of swine in residential census block groups of residence. Conditional logistic
regression models were used to derive odds ratio (OR) estimates and 95% confidence intervals (CI). Presence of the
scn gene in MRSA isolates was assessed. In addition, multi locus sequence typing (MLST) of the MRSA isolates was
performed, and the Diversilab® system was used to match the isolates to USA pulsed field gel electrophoresis types.
Results: From July - December 2011, 117 cases and 119 controls were enrolled. A higher proportion of controls
than cases were current workforce members (41.2% vs. 31.6%) Cases had a higher odds of living in census block
groups with medium densities of swine (OR: 4.76, 95% CI: 1.36-16.69) and of reporting the ability to smell odor from
a farm with animals when they were home (OR: 1.51, 95% CI: 0.80-2.86). Of 49 culture positive MRSA isolates, all
were scn positive. Twenty-two isolates belonged to clonal complex 5.
Conclusions: Absence of livestock workers in this study precluded evaluation of occupational exposures. Higher
odds of MRSA in medium swine density areas could reflect environmental exposure to swine or poultry
Medical and Household Characteristics Associated with Methicillin Resistant Staphylococcus aureus Nasal Carriage among Patients Admitted to a Rural Tertiary Care Hospital
BackgroundMethicillin resistant Staphylococcus aureus (MRSA) poses a threat to patient safety and public health. Understanding how MRSA is acquired is important for prevention efforts. This study investigates risk factors for MRSA nasal carriage among patients at an eastern North Carolina hospital in 2011.MethodsUsing a case-control design, hospitalized patients ages 18 – 65 years were enrolled between July 25, 2011 and December 15, 2011 at Vidant Medical Center, a tertiary care hospital that screens all admitted patients for nasal MRSA carriage. Cases, defined as MRSA nasal carriers, were age and gender matched to controls, non-MRSA carriers. In-hospital interviews were conducted, and medical records were reviewed to obtain information on medical and household exposures. Multivariable conditional logistic regression was used to derive odds ratio (OR) estimates of association between MRSA carriage and medical and household exposures.ResultsIn total, 117 cases and 119 controls were recruited to participate. Risk factors for MRSA carriage included having household members who took antibiotics or were hospitalized (OR: 3.27; 95% Confidence Interval (CI): 1.24–8.57) and prior hospitalization with a positive MRSA screen (OR: 3.21; 95% CI: 1.12–9.23). A lower proportion of cases than controls were previously hospitalized without a past positive MRSA screen (OR: 0.40; 95% CI: 0.19–0.87).ConclusionThese findings suggest that household exposures are important determinants of MRSA nasal carriage in hospitalized patients screened at admission
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