Relative density of United States forests has shifted to higher levels over last two decades with important implications for future dynamics.
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ABSTRACT:
SUBMITTER: Woodall CW
PROVIDER: S-EPMC8458300 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Mortality is a key indicator of forest health, and increasing mortality can serve as bellwether for the impacts of global change on forest ecosystems. Here we analyze trends in forest canopy mortality between 1984 and 2016 over more than 30 Mill. ha of temperate forests in Europe, based on a unique dataset of 24,000 visually interpreted spectral trajectories from the Landsat archive. On average, 0.79% of the forest area was affected by natural or human-induced mortality annually. Canopy mortality increased by +2.40% year-1, doubling the forest area affected by mortality since 1984. Areas experiencing low-severity mortality increased more strongly than areas affected by stand-replacing mortality events. Changes in climate and land-use are likely causes of large-scale forest mortality increase. Our findings reveal profound changes in recent forest dynamics with important implications for carbon storage and biodiversity conservation, highlighting the importance of improved monitoring of forest mortality.
| S-EPMC6255806 | biostudies-literature
Project description:Hepatitis C virus infection has been the most common etiology in HCC-related liver transplantation (LT). Since 2014, direct-acting antivirals (DAAs) have dramatically improved HCV cure. We aimed to study the changing pattern of etiologies and impact in outcome in HCC-related LT according to HCV treatment-era through retrospective analysis of the Scientific Registry of Transplant Recipients (SRTR) database (1987-2017). A total of 27 855 HCC-related liver transplants were performed (median age 59 years, 77% male). In the DAA era (2014-2017) there has been a 14.6% decrease in LT for HCV-related HCC; however, HCV remains the most common etiology in 50% of cases. In the same era, there has been a 50% increase in LT for NAFLD-related HCC. Overall survival was significantly worse for HCV-related HCC compared to NAFLD-related HCC during pre-DAA era (2002-2013; P = .031), but these differences disappeared in the DAA era. In addition, HCV patients had a significant improvement in survival when comparing the DAA era with IFN era (P < .001). Independent predictors of survival were significantly different in the pre-DAA era (HCV, AFP, diabetes) than in the DAA era (tumor size). HCV-related HCC continues to be the main indication for LT in the DAA era, but patients' survival has significantly improved and is comparable to that of NAFLD-related HCC.
| S-EPMC6940543 | biostudies-literature
Project description:ObjectiveAs the number of female medical students and surgical residents increases, the increasing number of female academic surgeons has been disproportionate. The purpose of this brief report is to evaluate the AAMC data from 1969 to 2018 to compare the level of female academic faculty representation for surgical specialties over the past four decades.DesignThe number of women as a percentage of the total surgeons per year were recorded for each year from 1969-2018, the most recent year available. Descriptive statistics were performed. Poisson regression examined the percentage of women in each field as the outcome of interest with the year and specialty (using general surgery as a reference) as two predictor variables.SettingData from the American Association of Medical Colleges (AAMC).ParticipantsAll full-time academic faculty physicians in the specialties of obstetrics and gynecology (OB/GYN), general surgery, ophthalmology, otolaryngology (ENT), plastic surgery, plastic surgery, urology, neurosurgery, orthopaedic surgery and cardiothoracic surgery as per AAMC records.ResultsThe percentage of women in surgery for all specialties evaluated increased from 1969 to 2018 (OR 1.04, p<0.001). Compared with general surgery, the rate of yearly percentage change increased more slowly in neurosurgery (OR 0.84; P = .004), orthopaedic surgery (OR 0.82; P = .002), urology (OR 0.59; P < .001), and cardiothoracic surgery (OR 0.38; P < .001). There was no significant difference in the rate of yearly percentage change for plastic surgery (OR 1.01; P = .840). The rate of yearly percentage change increased more rapidly in OB/GYN (OR 2.86; P < .001), ophthalmology (OR 1.79; P < .001) and ENT (OR 1.70; P < .001).ConclusionsRepresentation of women in academic surgery is increasing overall but is increasing more slowly in orthopaedic surgery, neurosurgery, cardiothoracic surgery and urology compared with that in general surgery. These data may be used to inform and further the discussion of how mentorship and sponsorship of female students and trainees interested in surgical careers may improve gender equity in the future.
| S-EPMC7743929 | biostudies-literature
Project description:BACKGROUND:Marijuana is the most widely used illicit drug in the United States and all over the world. Reports indicate that the potency of cannabis preparation has been increasing. This report examines the concentration of cannabinoids in illicit cannabis products seized by the U.S. Drug Enforcement Administration over the last 2 decades, with particular emphasis on ?(9)-tetrahydrocannabinol and cannabidiol. METHODS:Samples in this report were received over time from materials confiscated by the Drug Enforcement Administration and processed for analysis using a validated gas chromatography with flame ionization detector method. RESULTS:Between January 1, 1995, and December 31, 2014, 38,681 samples of cannabis preparations were received and analyzed. The data showed that although the number of marijuana samples seized over the last 4 years has declined, the number of sinsemilla samples has increased. Overall, the potency of illicit cannabis plant material has consistently increased over time since 1995 from ~4% in 1995 to ~12% in 2014. The cannabidiol content has decreased on average from ~.28% in 2001 to <.15% in 2014, resulting in a change in the ratio of ?(9)-tetrahydrocannabinol to cannabidiol from 14 times in 1995 to ~80 times in 2014. CONCLUSIONS:There is a shift in the production of illicit cannabis plant material from regular marijuana to sinsemilla. This increase in potency poses higher risk of cannabis use, particularly among adolescents.
| S-EPMC4987131 | biostudies-literature
Project description:Background and aimsLiver organ shortage remains a major health burden in the US, with more patients being waitlisted than the number of liver transplants (LTs) performed. This study investigated US national and regional trends in living donor LT (LDLT) and identified factors associated with recipient survival.MethodsWe retrospectively analyzed LDLT recipients and donors from the United Network Organ Sharing/Organ Procurement Transplant Network database from 1998 until 2019 for clinical characteristics, demographic differences, and survival rate. National and regional trends in LDLT, recipient outcomes, and predictors of survival were analyzed.ResultsOf the 223,571 candidates listed for an LT, 57.5% received an organ, of which only 4.2% were LDLTs. Annual adult LDLTs first peaked at 412 in 2001 but experienced a significant decline to 168 by 2009. LDLTs then gradually increased to 445 in 2019. Region 2 had the highest LDLT numbers (n=919), while region 1 had the highest proportion (11.1%). Overall, post-LT mortality was 21.4% among LDLT recipients. Post-LDLT survival rates after 1-, 5-, and 10-years were 92%, 87%, and 70%, respectively. Interval analysis (2004-2019) showed that patients undergoing LDLT in recent years had lower mortality than in earlier years (hazard ratio=0.81, 95% confidence interval=0.75-0.88).ConclusionsFollowing a substantial decline after a peak in 2001, the number of adult LDLTs steadily increased from 2011 to 2019. However, LDLTs still constitute the minority of the transplant pool in the US. Life-saving policies to increase the use of LDLTs, particularly in regions of high organ demand, should be implemented.
| S-EPMC9547266 | biostudies-literature
Project description:Despite the growing interest in predicting global and regional trends in vegetation productivity in response to a changing climate, changes in water constraint on vegetation productivity (i.e., water limitations on vegetation growth) remain poorly understood. Here we conduct a comprehensive evaluation of changes in water constraint on vegetation growth in the extratropical Northern Hemisphere between 1982 and 2015. We document a significant increase in vegetation water constraint over this period. Remarkably divergent trends were found with vegetation water deficit areas significantly expanding, and water surplus areas significantly shrinking. The increase in water constraints associated with water deficit was also consistent with a decreasing response time to water scarcity, suggesting a stronger susceptibility of vegetation to drought. We also observed shortened water surplus period for water surplus areas, suggesting a shortened exposure to water surplus associated with humid conditions. These observed changes were found to be attributable to trends in temperature, solar radiation, precipitation, and atmospheric CO2. Our findings highlight the need for a more explicit consideration of the influence of water constraints on regional and global vegetation under a warming climate.
| S-EPMC8213694 | biostudies-literature
Project description:BackgroundThe paper presents an overview of air quality in the 27 member countries of the European Union (EU) and the United Kingdom (previous EU-28), from 2000 to 2017. We reviewed the progress made towards meeting the air quality standards established by the EU Ambient Air Quality Directives (European Council Directive 2008/50/EC) and the World Health Organization (WHO) Air Quality Guidelines by estimating the trends (Mann-Kendal test) in national emissions of main air pollutants, urban population exposure to air pollution, and in mortality related to exposure to ambient fine particles (PM2.5) and tropospheric ozone (O3).ResultsDespite significant reductions of emissions (e.g., sulfur oxides: ~ 80%, nitrogen oxides: ~ 46%, non-methane volatile organic compounds: ~ 44%, particulate matters with a diameter lower than 2.5 µm and 10 µm: ~ 30%), the EU-28 urban population was exposed to PM2.5 and O3 levels widely exceeding the WHO limit values for the protection of human health. Between 2000 and 2017, the annual PM2.5-related number of deaths decreased (- 4.85 per 106 inhabitants) in line with a reduction of PM2.5 levels observed at urban air quality monitoring stations. The rising O3 levels became a major public health issue in the EU-28 cities where the annual O3-related number of premature deaths increased (+ 0.55 deaths per 106 inhabitants).ConclusionsTo achieve the objectives of the Ambient Air Quality Directives and mitigate air pollution impacts, actions need to be urgently taken at all governance levels. In this context, greening and re-naturing cities and the implementation of fresh air corridors can help meet air quality standards, but also answer to social needs, as recently highlighted by the COVID-19 lockdowns.
| S-EPMC7937352 | biostudies-literature
Project description:ObjectiveOpioid-related harm has risen in recent decades, but limited research describes the clinical burden of opioid poisoning to Australian EDs. We aimed to investigate hospital presentations with opioid poisoning over three decades.MethodsThis is an observational series of prospectively collected data investigating presentations of opioid poisoning to an ED in Newcastle (1990-2021). Type of opioid, naloxone administration, intubation, intensive care unit (ICU) admission, length of stay and death were extracted from the unit's database.ResultsThere were 4492 presentations in 3574 patients (median age 36, 57.7% female), increasing from an average of 93 presentations annually in the first decade to 199 in the third decade. Deliberate self-poisonings accounted for 3694 presentations (82.2%). Heroin dominated the 1990s, peaking in 1999 before decreasing. Prescription opioids then rose, with codeine (usually in paracetamol combination) predominating until 2018, after which oxycodone presentations exceeded them. Methadone consistently increased from six presentations annually in the first decade to 16 in the last decade. Naloxone was administered in 990 (22.0%) presentations and 266 (5.9%) were intubated, most frequently following methadone and heroin exposures. ICU admissions increased from 5% in 1990 to 16% in 2021. Codeine exposures resulted in less severe effects, whereas methadone had more severe effects overall. The median length of stay was 17 h (interquartile range 9-27 h). There were 28 deaths (0.6%).ConclusionOpioid presentations increased in number and severity over three decades as the type of opioid changed. Oxycodone is currently the main opioid of concern. Methadone poisoning was the most severe.
| S-EPMC10947284 | biostudies-literature
Project description:Domestic rice (Oryza sativa L.) is one of the most important cereal crops, feeding a large number of worldwide populations. Along with various high-throughput genome sequencing projects, rice genomics has been making great headway toward direct field applications of basic research advances in understanding the molecular mechanisms of agronomical traits and utilizing diverse germplasm resources. Here, we briefly review its achievements over the past two decades and present the potential for its bright future.
| S-EPMC6411948 | biostudies-literature
Project description:It is largely unknown how South America's Andean forests affect the global carbon cycle, and thus regulate climate change. Here, we measure aboveground carbon dynamics over the past two decades in 119 monitoring plots spanning a range of >3000 m elevation across the subtropical and tropical Andes. Our results show that Andean forests act as strong sinks for aboveground carbon (0.67 ± 0.08 Mg C ha-1 y-1) and have a high potential to serve as future carbon refuges. Aboveground carbon dynamics of Andean forests are driven by abiotic and biotic factors, such as climate and size-dependent mortality of trees. The increasing aboveground carbon stocks offset the estimated C emissions due to deforestation between 2003 and 2014, resulting in a net total uptake of 0.027 Pg C y-1. Reducing deforestation will increase Andean aboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change.
| S-EPMC8035207 | biostudies-literature