The study of marijuana use disorders is urgently needed because of increasing marijuana legalisation in multiple jurisdictions, the effect of marijuana use on future risk of psychiatric disorders, ...and deleterious effects of marijuana exposure. Thus, understanding trends of marijuana use and use disorders and examining factors that might drive these trends (eg, perceptions of harms from marijuana use) is essential.
We analysed data from US civilians aged 18 years or older who participated in annual, cross-sectional US National Surveys on Drug Use and Health from 2002 to 2014. The sample in each US state was designed to be approximately equally distributed between participants aged 12-17 years, 18-25 years, and 26 years or older. For each survey year, we estimated prevalence of marijuana use and use disorders, initiation of marijuana use, daily or near daily use, perception of great or no risk of harm from smoking marijuana, perception of state legalisation of medical marijuana use, and mean number of days of marijuana use in the previous year. Descriptive analyses, multivariable logistic regressions, and zero-truncated negative binomial regressions were applied.
596 500 adults participated in the 2002-14 surveys. Marijuana use increased from 10·4% (95% CI 9·97-10·82) to 13·3% (12·84-13·70) in adults in the USA from 2002 to 2014 (β=0·0252, p<0·0001), and the prevalence of perceiving great risk of harm from smoking marijuana once or twice a week decreased from 50·4% (49·60-51·25) to 33·3% (32·64-33·96; β=-0·0625, p<0·0001). Changes in marijuana use and risk perception generally began in 2006-07. After adjusting for all covariates, changes in risk perceptions were associated with changes in prevalence of marijuana use, as seen in the lower prevalence of marijuana use each year during 2006-14 than in 2002 when perceiving risk of harm from smoking marijuana was included in models. However, marijuana use disorders in adults remained stable at about 1·5% between 2002 and 2014 (β=-0·0042, p=0·22).
Prevalence and frequency of marijuana use increased in adults in the USA starting in approximately 2007 and showing significantly higher results in multivariable models during 2011-14 (compared with 2002). The associations between increases in marijuana use and decreases in perceiving great risk of harm from smoking marijuana suggest the need for education regarding the risk of smoking marijuana and prevention messages.
None.
José Eduardo Agualusa's My Father's Wives celebrates a liberation of the strictures usually underpinning identity construction, by both affirming those notions and simultaneously undercutting their ...validity. The novel proposes a textual and cultural celebratory promiscuousness as way of reimagining a Creole identity that goes beyond the customary dual poles of Portugal and Angola to embrace most of Southern Africa as well as Asia. The contradictions spawned by this strategy open up a gap that is filled with signs of excess and slippage, the result of a parodic mimicry and the failure of the paternal function at the textual and personal levels. Structured around the search for Faustino Manso and his alleged seventeen children, the discovery of his infertility empties out his paternal function and puts into doubt the Lusotropical stereotype of Creoleness. This geocultural polyphony is replicated at the textual level with the presence of an unnamed narrator-figure whose metatextual narrative serves as authorial framing for the fictional text. However, the replication of the fictional narrative within the authorial text—with some seepage of the latter into the former—again points to both mimicry and excess. This paper will argue that by emptying the two vectors structuring the text of their narrative objectives, My Father's Wives constitutes the doubly absent paternities of a Luandan Creole stereotype typically projected over the rest of the nation.
Eduardo Mendicutti's Yo no tengo la culpa de haber nacido tan sexy introduces two marginal characters within a parody of Teresian mysticism and quixotic idealism to question the role played by these ...icons and the canonized narratives surrounding them in defining the national body and identity. The introjection of the transsexual body into mystical discourse reveals a corporeal politics grounded in repression and exclusion, showing how unstable identities are intimately linked not only with past narratives now considered canonical markers of Spanish essence and identity, but also with the real-life practices of rural and traditional Castile.
Lightning and the African ITCZ Collier, Andrew B.; Hughes, Arthur R.W.
Journal of atmospheric and solar-terrestrial physics,
10/2011, Letnik:
73, Številka:
16
Journal Article
Recenzirano
The idea that tropical lightning activity follows the motion of the Intertropical Convergence Zone (ITCZ) is based on anecdotal evidence, or at best indirect measurements. Definitive observations of ...lightning from satellite instruments are used here to demonstrate that the seasonal motion of peak lightning over tropical Africa has the same phase as the migration of the ITCZ but that there is no precise space-time coincidence. It is also shown that over shorter time scales the tropical band of lightning activity does not simply follow the Sun nor does it adhere to the ITCZ. What emerges is a complex pattern of behaviour which, though clearly influenced by solar declination and the ITCZ, is also determined by the underlying terrain and humidity. It is sometimes considered that lightning in the tropics would be a good locator of the ITCZ, it is shown here that this is not the case.
► Tropical lightning distribution determined from satellite data. ► ITCZ location determined from pressure and wind reanalysis data. ► Peak tropical lightning is not a good indicator of ITCZ location.
Eduardo Mendicutti's
Yo no tengo la culpa de haber nacido tan sexy
introduces two marginal characters within a parody of Teresian mysticism and quixotic idealism to question the role played by these ...icons and the canonized narratives surrounding them in defining the national body and identity. The introjection of the transsexual body into mystical discourse reveals a corporeal politics grounded in repression and exclusion, showing how unstable identities are intimately linked not only with past narratives now considered canonical markers of Spanish essence and identity, but also with the real-life practices of rural and traditional Castile.
Satellite observations of cloud top temperature and lightning flash distribution are used to examine the relationship between deep convection and lightning activity over the tropical regions of the ...northern and southern hemispheres. In agreement with previous work, the analysis of the results shows that, in the summer of both hemispheres, the lightning activity in continental deep convective storms is more intense than that in marine deep convective storms by a factor of between 7 and 10. Furthermore, it was observed that on average the daily lightning rate per 1°×1° grid cell for the southern hemisphere (SH) is about 20% greater than that of the northern hemisphere (NH), which can be attributed to a larger fractional cover by deep convective clouds in the SH. By using a set of independent indicators, it is shown that deep convection and lightning activity over land are well correlated (with correlation coefficients of 0.8 and 0.6 for NH and SH, respectively). This suggests the capacity for observations to act as a possible method of monitoring continental deep convective clouds, which play a key role in regulating the Earth’s climate. Since lightning can be monitored easily from ground networks and satellites, it could be a useful tool for validating the performance of model convective schemes and for monitoring changes in climate parameters.
Vegetation cover is an important factor controlling erosion and sediment yield. Therefore, its effect is accounted for in both experimental and modelling studies of erosion and sediment yield. ...Numerous studies have been conducted to account for the effects of vegetation cover on erosion across spatial scales; however, little has been conducted across temporal scales. This study investigates changes in vegetation cover across multiple temporal scales in Eastern Cape, South Africa and how this affects erosion and sediment yield modelling in the Tsitsa River catchment. Earth observation analysis and sediment yield modelling are integrated within this study. Landsat 8 imagery was processed, and Normalised Difference Vegetation Index (NDVI) values were extracted and applied to parameterise the Modified Universal Soil Loss Equation (MUSLE) vegetation (C) factor. Imagery data from 2013–2018 were analysed for an inter-annual trend based on reference summer (March) images, while monthly imagery for the years 2016–2017 was analysed for intra-annual trends. The results indicate that the C exhibits more variation across the monthly timescale than the yearly timescale. Therefore, using a single month to represent the annual C factor increases uncertainty. The modelling shows that accounting for temporal variations in vegetation cover reduces cumulative simulated sediment by up to 85% across the inter-annual and 30% for the intra-annual scale. Validation with observed data confirmed that accounting for temporal variations brought cumulative sediment outputs closer to observations. Over-simulations are high in late autumn and early summer, when estimated C values are high. Accordingly, uncertainties are high in winter when low NDVI leads to high C, whereas dry organic matter provides some protection from erosion. The results of this study highlight the need to account for temporal variations in vegetation cover in sediment yield estimation but indicate the uncertainties associated with using NDVI to estimate C factor.
The proposed site for the construction of a new dam (Laleni Dam) on the Tsitsa River in the Eastern Cape, South Africa falls within a high soil erosion zone, which is expected to affect the lifespan ...of the dam. Estimating the sediment yield of the catchment is important from a management perspective, and thus we designed this study to assess the applicability of the Modified Universal Soil Loss Equation (MUSLE). The original MUSLE was applied to the Inxu River sub catchment, upstream of a proposed dam, over a summer rainfall period extending from October 2016 to April 2017. A modified version of the MUSLE, incorporating a storage module, was later applied over the same period. Model calibration of the MUSLE with and without a storage model was tested against 7 months of recorded daily suspended sediment discharge data. With a storage model, we achieved a percentage bias, coefficient of efficiency and R2 of 2%, 0.83 and 0.83, respectively, while without storage the performance statistics were markedly lower. These results suggest that a calibrated MUSLE can provide estimates of sediment yield that are valuable for regional planning, and that the inclusion of a storage component further improves the MUSLE application. Given the complexity of sediment generation and transport processes, a relatively simple empirical MUSLE model is a useful tool for initial sediment yield estimation for planning purposes.
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