49 research outputs found

    Late Holocene climate anomaly concurrent with fire activity and ecosystem shifts in the eastern Australian Highlands

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    The alpine area of the Australian mainland is highly sensitive to climate and environmental change, and potentially vulnerable to ecosystem tipping points. Over the next two decades the Australian alpine region is predicted to experience temperature increases of at least 1 °C, coupled with a substantial decrease in snow cover. Extending the short instrumental record in these regions is imperative to put future change into context, and potentially provide analogues of warming. We reconstructed past temperatures, using a lipid biomarker palaeothermometer technique and mercury flux changes for the past 3500 years from the sediments of Club Lake, a high-altitude alpine tarn in the Snowy Mountains, southeastern Australia. Using a multi-proxy framework, including pollen and charcoal analyses, high-resolution geochemistry, and ancient microbial community composition, supported by high-resolution 210Pb and AMS 14C dating, we investigated local and regional ecological and environmental changes occurring in response to changes in temperature. We find the region experienced a general warming trend over the last 3500 years, with a pronounced climate anomaly occurring between 1000 and 1600 cal yrs. BP. Shifts in vegetation took place during this warm period, characterised by a decline in alpine species and an increase in open woodland taxa which co-occurred with an increase in regional fire activity. Given the narrow altitudinal band of Australian alpine vegetation, any future warming has the potential to result in the extinction of alpine species, including several endemic to the area, as treelines are driven to higher elevations. These findings suggest ongoing conservation efforts will be needed to protect the vulnerable alpine environments from the combined threats of climate changes, fire and invasive species.Zoë A. Thomas, Scott Mooney, Haidee Cadd, Andy Baker, Chris Turney, Larissa Schneider, Alan Hogg, Simon Haberle, Ken Green, Laura S. Weyrich, Vilma Pérez, Nicole E. Moore, Atun Zawadzki i, Sarah J. Kelloway, Stuart J. Kha

    A Randomized Placebo-Controlled Trial of \u3cem\u3eN\u3c/em\u3e-Acetylcysteine for Cannabis Use Disorder in Adults

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    Background—Cannabis use disorder (CUD) is a prevalent and impairing condition, and established psychosocial treatments convey limited efficacy. In light of recent findings supporting the efficacy of N-acetylcysteine (NAC) for CUD in adolescents, the objective of this trial was to evaluate its efficacy in adults. Methods—In a 12-week double-blind randomized placebo-controlled trial, treatment-seeking adults ages 18–50 with CUD (N=302), enrolled across six National Drug Abuse Treatment Clinical Trials Network-affiliated clinical sites, were randomized in a 1:1 ratio to a 12-week course of NAC 1200 mg (n=153) or placebo (n=149) twice daily. All participants received contingency management (CM) and medical management. The primary efficacy measure was the odds of negative urine cannabinoid tests during treatment, compared between NAC and placebo participants. Results—There was not statistically significant evidence that the NAC and placebo groups differed in cannabis abstinence (odds ratio = 1.00, 95% confidence interval 0.63 – 1.59; p=0.984). Overall, 22.3% of urine cannabinoid tests in the NAC group were negative, compared with 22.4% in the placebo group. Many participants were medication non-adherent; exploratory analysis within medication-adherent subgroups revealed no significant differential abstinence outcomes by treatment group. Conclusions—In contrast with prior findings in adolescents, there is no evidence that NAC 1200 mg twice daily plus CM is differentially efficacious for CUD in adults when compared to placebo plus CM. This discrepant finding between adolescents and adults with CUD may have been influenced by differences in development, cannabis use profiles, responses to embedded behavioral treatment, medication adherence, and other factors

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Social Determinants of Mortality of COVID-19 and Opioid Overdose in American Rural and Urban Counties

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    Both COVID-19 deaths and opioid overdose deaths continue to increase in the United States. Little is known about the characteristics of counties with high rates of mortality for both. METHODS: We analyzed county-level data on COVID-19 mortality from January 1 to May 31, 2020, and on opioid overdose mortality during 2014-2018. The outcome variable, “high-risk county” was a binary indicator of high mortality rates (above 75% quartile) for both COVID-19 and opioid overdose. We conducted geospatial logistic regression models separately for urban and rural counties to identify social determinants of health associated with being a high-risk county. RESULTS: After adjusting for other covariates, the overall mortality rate of COVID-19 is higher in counties with larger population size and a higher proportion of racial/ethnic minorities, although counties with high rates of opioid overdose mortality have lower proportions of racial/ethnic minorities, a higher proportion of females, and are more economically disadvantaged. Significant predictors of rural counties with high mortality rates for both COVID-19 and opioid overdose include higher proportions of Blacks (Adjusted odds ratio [aOR], 1.04; 95%CI, 1.01–1.07), American Indians and Alaska Natives (aOR, 1.07; 95%CI, 1.02–1.13), and two or more races (aOR, 1.34; 95%CI, 1.13–1.60). Additional predictors for high-risk urban counties include population density (aOR, 1.12; 95%CI, 1.04–1.22) and higher unemployment rates during the COVID-19 pandemic (aOR, 1.23; 95%CI, 1.07–1.41). CONCLUSIONS: Rural counties with high proportions of racial/ethnic minorities and urban counties with high unemployment rates are at high mortality risk for COVID-19 and opioid overdose

    Association Between Benzodiazepine and Opioid Prescription and Mortality Among Patients in a Large Healthcare System

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    OBJECTIVE: Co-prescription of opioids and benzodiazepines (BDZ) is associated with adverse outcomes, including greater healthcare utilization and overdose risk. This study aims to examine opioid and BDZ co-prescription, dosing, and mortality among patients with and without opioid use disorder (OUD) in a large healthcare system. METHODS: Using data from the California state Prescription Drug Monitoring Program during 2010–2014 linked with a large healthcare system electronic health record database and mortality records from the Centers for Disease Control National Death Index, this study examined 5,202 patients (1,978 with OUD, 3,224 controls). Multiple logistic regression analyses were conducted to examine relationships between most recent BDZ and opioid prescription, and their interaction with respect to mortality. RESULTS: 10.5% of the sample died on or before December 31, 2014. 17.7% were prescribed BDZ during the final month of observation. Individuals with OUD were prescribed higher average BDZ and opioid doses than those without OUD. After adjusting for covariates, increased prescribed doses of BDZ (odds ratio [OR]=1.34, 95%CI: 1.15–1.55 per 10 mg/day increment) and opioids (OR=1.04, 95%CI: 1.02–1.05 per 10 mg/day increment) were positively associated with mortality. Non-OUD patients who received both BDZ and opioid prescriptions had a higher mortality than those who received only BDZ or opioids (The ratio of odds ratio (ROR) =3.83, 95%CI: 1.78–8.21). CONCLUSIONS: Study findings highlight significant mortality associated with the co-prescription of opioids and BDZ in a general healthcare setting. Further research is needed to elucidate factors associated with mortality among non-OUD patients who are co-prescribed opioids and BDZ

    The impact of COVID-19 on substance use disorder treatment in California: Service providers' perspectives.

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    BackgroundThe COVID-19 pandemic has had a profound impact on the U.S. health care system, including addiction treatment. The objective of this study is to describe the impact of COVID on the delivery of treatment for substance use disorders (SUDs) from the perspectives of service providers.MethodsBetween May and September 2020, 61 service providers from 16 SUD treatment sites in California participated in virtual focus groups that lasted about an hour. We recorded the discussions and transcribed them verbatim. Two qualitative analysts independently conducted content analysis to identify themes from the transcripts.ResultsAt the beginning of the pandemic, service providers observed a slight decrease in patient admissions, followed by an uptick in patient flow due to increased mental health issues, alcohol use, and relapse. Many of the clinics adopted flexible service delivery modes, such as curbside dosing and extended take-home medication, to enable social distancing in clinic settings. Approximately half of the clinic encounters offered telemedicime, and a considerable proportion of patients preferred to use telephone-based services rather than video-based services. Internet instability and technical difficulties limited the use of telemedicine among their patients.ConclusionCOVID has been challenging for SUD treatment, but health care systems rapidly reacted with adjustments that may result in long-term changes in SUD service delivery. Telemedicine-based services have played a major role in ensuring uninterrupted patient care. Providers need organizational, technical, and logistical support to improve and sustain telemedicine services that increase access to quality care for their patients
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