529 research outputs found
Harms and benefits associated with psychoactive drugs: Findings of an international survey of active drug users
There have been several recent efforts in the UK and the Netherlands to describe the harms of psychoactive substances based on ratings of either experts or drug users. This study aimed to assess the perceived benefits as well as harms of widely used recreational drugs, both licit and illicit, in an international sample of drug users. The survey was hosted at https://www.internationaldrugsurvey.org/ and was available in three languages. Residents reported their experience of 15 commonly used drugs or drug classes; regular users then rated their harms and benefits. In all, 5791 individuals from over 40 countries completed the survey, although the majority were from English speaking countries. Rankings of drugs differed across 10 categories of perceived benefits. Skunk and herbal cannabis were ranked consistently beneficial, whilst alcohol and tobacco fell below many classified drugs. There was no correlation at all between usersâ harm ranking of drugs and their classification in schedules of the USA or ABC system in the UK. Prescription analgesics, alcohol and tobacco were ranked within the top 10 most harmful drugs. These findings suggest that neither the UK nor US classification systems act to inform users of the harms of psychoactive substances. It is hoped the results might inform health professionals and educators of what are considered to be both the harms and benefits of psychoactive substances to young people
A 700 year record of Southern Hemisphere extratropical climate variability
Annually dated ice cores from West and East Antarctica provide proxies for past changes in atmospheric circulation over Antarctica and portions of the Southern Ocean, temperature in coastal West and East Antarctica, and the frequency of South Polar penetration of El Niño events. During the period AD 1700â1850, atmospheric circulation over the Antarctic and at least portions of the Southern Hemisphere underwent a mode switch departing from the out-of-phase alternation of multi-decadal long phases of EOF1 and EOF2 modes of the 850 hPa field over the Southern Hemisphere (as defined in the recent record by Thompson and Wallace, 2000; Thompson and Solomon, 2002) that characterizes the remainder of the 700 year long record. From AD 1700 to 1850, lower-tropospheric circulation was replaced by in-phase behavior of the Amundsen Sea Low component of EOF2 and the East Antarctic High component of EOF1. During the first phase of the mode switch, both West and East Antarctic temperatures declined, potentially in response to the increased extent of sea ice surrounding both regions. At the end of the mode switch, West Antarctic coastal temperatures rose and East Antarctic coastal temperatures fell, respectively, to their second highest and lowest of the record. Polar penetration of El Niño events increased during the mode switch. The onset of the AD 1700â1850 mode switch coincides with the extreme state of the Maunder Minimum in solar variability. Late 20th-century West Antarctic coastal temperatures are the highest in the record period, and East Antarctic coastal temperatures close to the lowest. Since AD 1700, extratropical regions of the Southern Hemisphere have experienced significant climate variability coincident with changes in both solar variability and greenhouse gase
High-precision Dating of Volcanic Events (A.D. 1301â1995) Using Ice Cores from Law Dome, Antarctica
A record of volcanic activity over the period A.D. 1301â1995 has been extracted from three Law Dome ice cores (East Antarctica). The record dating is unambiguous at the annual level from A.D. 1807 to 1995 and has an uncertainty of ±1 year at A.D. 1301. Signals from 20 eruptions are preserved in the record, including those of two unknown eruptions with acid deposition beginning in A.D. 1810.8 and A.D. 1685.8. The beginning of the ice core signal from the A.D. 1815 Tambora eruption is observed in the austral summer of A.D. 1816/1817. The mean observed stratospheric transport and deposition time to Law Dome from the eruption site is 1.5 years (Ï = 0.6 years) from 11 well-dated eruptions. The largest eruption observed in the Law Dome record has its maximum in A.D. 1460 with volcanic sulfate deposition beginning in the austral winter of A.D. 1459. This event is also observed in other ice core records and is attributed to the volcano Kuwae, with an eruption date in the range A.D. 1455.9â1459.9 if all sources of error are considered. This is at least three years later than the date previously ascribed by dendrochronological and historical studies
Study of Mill Island ice core (East Antarctica): A sensitive site for high resolution ocean climate signals?
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Changes in Black Carbon Deposition to Antarctica from Two Ice Core Records, A.D. 1850-2000
Continuous flow analysis was based on a steady sample flow and in-line detection of BC and other chemical substances as described in McConnell et al. (2007). In the cold room, previously cut one meter ice core sticks of 3x3cm, are melted continuously on a heated melter head specifically designed to eliminate contamination from the atmosphere or by the external parts of the ice. The melted ice from the most inner part of the ice stick is continuously pumped by a peristaltic pump and carried to a clean lab by Teflon lines. The recorded signal is continuous, integrating a sample volume of about 0.05 mL, for which the temporal resolution depends on the speed of melting, ice density and snow accumulation rate at the ice core drilling site. For annual accumulation derived from the WAIS and Law Dome ice cores, we assumed ~3.1 cm water equivalent uncertainty in each year's accumulation from short scale spatial variability (glaciological noise) which was determined from several measurements of annual accumulation in multiple parallel ice cores notably from the WAIS Divide ice core site (Banta et al., 2008) and from South Pole site (McConnell et al., 1997; McConnell et al., 2000). Refractory black carbon (rBC) concentrations were determined using the same method as in (Bisiaux et al., 2011) and adapted to continuous flow measurements as described by (McConnell et al., 2007). The technique uses a single particle intracavity laser induced incandescence photometer (SP2, Droplet Measurement Technologies, Boulder, Colorado) coupled to an ultrasonic nebulizer/desolvation (CETAC UT5000) Flow Injection Analysis (FIA). All analyses, sample preparation etc, were performed in a class 100 cleanroom using anti contamination "clean techniques". The samples were not acidified
Thinking about growth : a cognitive mapping approach to understanding small business development
School of Managemen
Notes on the Biology of an Adult Female Chimaera cubana Captured Off St. Croix, U.S. Virgin Islands
Within the western North Atlantic Ocean there are at least 4 genera and 5 species of chimaeroids occurring in deep waters generally associated with outer continental slopes or areas of high bathymetric relief (Didier 2002; Didier 2004). Two chimaeroids, Chimaera cubana and Hydrolagus alberti, are known to be indigenous to the Caribbean Sea in waters associated with the Greater and Lesser Antilles. While H. alberti occurs throughout the Gulf of Mexico and the Caribbean Sea, C. cubana is thought to be endemic to an area bounded by Cuba and Colombia (IUCN 2009). These two chimaeras are readily differentiated by the presence or absence of an anal fin and speciesâspecific branching patterns of cranial lateral line canals (Didier 2004). Since the description of C. cubana by HowellâRivero (1936), only 10 specimens have been reported in the primary literature with another 11 specimens located in museum collections (BunkleyâWilliams and Williams 2004). The dearth of biological information on C. cubana led the International Union for the Conservation of Nature to recommend that âbasic data be collected on all capturesâ (IUCN 2009)
Clinical validation of a spectroscopic liquid biopsy for earlier detection of brain cancer
BackgroundDiagnostic delays impact the quality of life and survival of patients with brain tumors. Earlier and expeditious diagnoses in these patients are crucial to reduce the morbidities and mortalities associated with brain tumors. A simple, rapid blood test that can be administered easily in a primary care setting to efficiently identify symptomatic patients who are most likely to have a brain tumor would enable quicker referral to brain imaging for those who need it most.MethodsBlood serum samples from 603 patients were prospectively collected and analyzed. Patients either had non-specific symptoms that could be indicative of a brain tumor on presentation to the Emergency Department, or a new brain tumor diagnosis and referral to the neurosurgical unit, NHS Lothian, Scotland. Patient blood serum samples were analyzed using the DxcoverÂź Brain Cancer liquid biopsy. This technology utilizes infrared spectroscopy combined with a diagnostic algorithm to predict the presence of intracranial disease.ResultsOur liquid biopsy approach reported an area under the receiver operating characteristic curve of 0.8. The sensitivity-tuned model achieves a 96% sensitivity with 45% specificity (NPV 99.3%) and identified 100% of glioblastoma multiforme patients. When tuned for a higher specificity, the model yields a sensitivity of 47% with 90% specificity (PPV 28.4%).ConclusionsThis simple, non-invasive blood test facilitates the triage and radiographic diagnosis of brain tumor patients while providing reassurance to healthy patients. Minimizing time to diagnosis would facilitate the identification of brain tumor patients at an earlier stage, enabling more effective, less morbid surgical and adjuvant care
Whole-genome sequencing to understand the genetic architecture of common gene expression and biomarker phenotypes.
Initial results from sequencing studies suggest that there are relatively few low-frequency (<5%) variants associated with large effects on common phenotypes. We performed low-pass whole-genome sequencing in 680 individuals from the InCHIANTI study to test two primary hypotheses: (i) that sequencing would detect single low-frequency-large effect variants that explained similar amounts of phenotypic variance as single common variants, and (ii) that some common variant associations could be explained by low-frequency variants. We tested two sets of disease-related common phenotypes for which we had statistical power to detect large numbers of common variant-common phenotype associations-11 132 cis-gene expression traits in 450 individuals and 93 circulating biomarkers in all 680 individuals. From a total of 11 657 229 high-quality variants of which 6 129 221 and 5 528 008 were common and low frequency (<5%), respectively, low frequency-large effect associations comprised 7% of detectable cis-gene expression traits [89 of 1314 cis-eQTLs at P < 1 Ă 10(-06) (false discovery rate âŒ5%)] and one of eight biomarker associations at P < 8 Ă 10(-10). Very few (30 of 1232; 2%) common variant associations were fully explained by low-frequency variants. Our data show that whole-genome sequencing can identify low-frequency variants undetected by genotyping based approaches when sample sizes are sufficiently large to detect substantial numbers of common variant associations, and that common variant associations are rarely explained by single low-frequency variants of large effect
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