1,130 research outputs found
Offspring of Prenatal IV Nicotine Exposure Exhibit Increased Sensitivity to the Reinforcing Effects of Methamphetamine
Maternal smoking during pregnancy is associated with increased substance abuse in offspring. Preclinical research shows that in utero exposure to nicotine, the primary psychoactive compound in tobacco smoke, influences the neurodevelopment of reward systems and alters motivated behavior in offspring. The present study determined if prenatal nicotine (PN) exposure altered the sensitivity to the reinforcing and aversive effects of methamphetamine (METH) in offspring using a low dose, intravenous (IV) exposure method. Pregnant dams were administered nicotine (0.05 mg/kg/injection) or prenatal saline (PS) 3×/day on gestational days 8–21, and adult offspring were tested using METH self-administration (experiment 1) or METH-induced conditioned taste aversion (CTA; experiment 2) procedures. For METH self-administration, animals were trained to respond for IV METH (0.05 mg/kg/infusion; fixed-ratio 3) and they were tested on varying doses of the reinforcer (0.0005–1.0 mg/kg/infusion). For METH CTA, rats received three saccharin and METH pairings (0, 0.3, or 0.5 mg/kg, sc) followed by 14 daily extinction trials. Experiment 1: PN and PS animals exhibited inverted U-shaped dose-response curves; however, the PN animal’s curve was shifted to the left, suggesting PN animals were more sensitive to the reinforcing effects of METH. Experiment 2: METH CTA was acquired in a dose-dependent manner and the factor of PN exposure was not related to the acquisition or extinction of METH-induced CTA. There were no sex differences in either experiment. These results indicate that IV PN-exposed adult offspring exhibited increased sensitivity to IV METH. This suggests that PN exposure, via maternal smoking, will alter the reinforcing effects of METH during later stages of development, and furthermore, will influence substance use vulnerability in adult human offspring
EFFECTS OF MECHANICALLY GENERATED SLASH PARTICLE SIZE ON PRESCRIBED FIRE BEHAVIOR AND SUBSEQUENT VEGETATION EFFECTS
Forest managers have begun to restore ecosystem structure and function in fire-prone ecosystems that have experienced fire exclusion, commodity based resource extraction, and extensive grazing during much of the 20th century. Mechanical thinning and prescribed burning are the primary tools for thinning dense stands and restoring pre-settlement forest structure, reducing the likelihood of devastating crown fires. Mechanical thinning can be costly when trees are nonmerchantable and prescribed burning can be risky unless fuel loadings are first reduced. Furthermore, stands that remain dense after commercial thinning can produce undesirable wildland fire- or even prescribed fire- effects on vegetation and soils. Land managers are interested in using mastication equipment (Fig. 1) for thinning nonmerchantable trees as a means of restoring structure and function to dry forest ecosystems. However, it is unknown how the addition of mechanically derived slash influences potential fire behavior and fire effects. The objectives of this project were to test the effectiveness of mastication effort (defined as time needed to break fuels into smaller pieces) to 1) thin dense stands of dry coniferous forest within historically frequent, low-severity fire regimes (Fig. 1) and 2) create surface fuel beds that produce prescribed fire behavior with positive effects on residual trees, understory vegetation, and soils. Specifically, we asked the following questions: (1) How does slash particle size and fuel bed depth affect fire intensity and severity? (2) How do different mastication efforts and subsequent prescribed fire affect overstory vegetation? (3) Does soil heating change from burning different types of masticated slash? and (4) What are the differences in production costs among levels of mastication effort
Intravenous Prenatal Nicotine Exposure Alters METH-Induced Hyperactivity, Conditioned Hyperactivity, and BDNF in Adult Rat Offspring
In the USA, approximately 15% of women smoke tobacco cigarettes during pregnancy. In utero tobacco smoke exposure produces somatic growth deficits like intrauterine growth restriction and low birth w
P18-11. DALIA: dendritic cell and lipopeptide-induced immunity against AIDS: a phase I trial
International audiencen.
Barriers to help-seeking among music festival attendees in New South Wales, Australia
Introduction: Prompt help-seeking behaviour by music festival attendees can reduce risks associated with drug use; however, little is known about perceived barriers to help-seeking when experiencing or witnessing illness at music festivals. We explored potential barriers and their association with festivalgoer characteristics. Methods: We conducted an on-site cross-sectional survey of attendees at New South Wales music festivals in 2019/2020. Perceived barriers to help-seeking in the hypothetical event of the respondent or a friend becoming unwell at the festival were assessed, and regression analyses were conducted to identify characteristics associated with these barriers. Results: Across six festivals, 1229 people were surveyed and four-fifths (83.2%) reported ≥1 barrier: 32.7% fear of getting in trouble with the police, 20.6% not knowing where to find help, 17.2% not knowing how unwell someone might be and 15.3% concern about friends or relatives finding out. In multivariable analyses, people of diverse sexuality and people using drugs that day had greater odds of reporting fear of trouble with the police. People reporting drug use that day had lower odds of reporting not knowing where to find help. Men, gender-diverse people and people using drugs that day had greater odds of reporting concern about friends or relatives finding out. Discussion and Conclusions: Our data substantiate concerns regarding policing strategies and their impact on festivals. Initiatives to support conversations about drugs with friends and families may be best targeted to younger people and those from gender-diverse backgrounds
Are Labour Markets Necessarily Local? Spatiality, Segmentation and Scale
This paper draws on recent debates about scale to approach the geography of labour markets from a dynamic perspective sensitive to the spatiality and scale of labour market
restructuring. Its exploration of labour market reconfigurations after the collapse of a major firm (Ansett Airlines) raises questions about geography’s faith in the inherently ‘local’ constitution of labour markets. Through an examination of the job reallocation process after redundancy, the paper suggests that multiple labour markets use and articulate scale in different ways. It argues that labour market rescaling processes are enacted at the critical moment of recruitment, where social networks, personal aspirations and employer preferences combine to shape workers’ destinations
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