Hydropyrolysis: implications for radiocarbon pre-treatment and characterization of Black Carbon

Charcoal is the result of natural and anthropogenic burning events, when biomass is exposed to elevated temperatures under conditions of restricted oxygen. This process produces a range of materials, collectively known as pyrogenic carbon, the most inert fraction of which is known as Black Carbon (BC). BC degrades extremely slowly, and is resistant to diagenetic alteration involving the addition of exogenous carbon making it a useful target substance for radiocarbon dating particularly of more ancient samples, where contamination issues are critical. We present results of tests using a new method for the quantification and isolation of BC, known as hydropyrolysis (hypy). Results show controlled reductive removal of non-BC organic components in charcoal samples, including lignocellulosic and humic material. The process is reproducible and rapid, making hypy a promising new approach not only for isolation of purified BC for 14C measurement but also in quantification of different labile and resistant sample C fractions

Sex Disparities in Arrest Outcomes for Domestic Violence

Domestic violence arrests have been historically focused on protecting women and children from abusive men. Arrest patterns continue to reflect this bias with more men arrested for domestic violence compared to women. Such potential gender variations in arrest patterns pave the way to the investigation of disparities by sex of the offender in domestic violence arrests. This study utilizes data from a quantitative dataset that includes responses by police officers who completed a specially mandated checklist after responding to a domestic dispute. The results showed that while females are arrested quite often in domestic disputes, there remains a significant difference in the arrest outcome whereby male suspects were more likely to be arrested than female suspects. Regression models further indicated differences based on sex and certain predictors of arrest, which supported sex-based rationales in arrests for domestic violence.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Processos de democracia direta: sim ou não? Os argumentos clássicos à luz da teoria e da prática

Regularmente surgem controvérsias sobre os processos de democracia direta, dos quais os mecanismos mais frequentes são a iniciativa popular, o plebiscito e o referendo. Por um lado, há autores que defendem a posição de que essas instituições tornam o jogo político mais lento, caro, confuso e ilegítimo; outros defendem a posição contrária e argumentam que processos de democracia direta são fundamentais para os cidadãos e a qualidade da democracia. O presente estudo analisa esse tema em torno de sete questões, baseadas em considerações teóricas e pesquisas empíricas: 1. A questão entre o minimalismo e o maximalismo democrático; 2. A concorrência entre maioria e minoria; 3. A concorrência entre as instituições representativas e os processos de democracia direta; 4. A questão da competência dos cidadãos; 5. A questão dos efeitos colaterais dos processos de democracia direta; 6. A questão do tamanho do eleitorado; 7. A questão dos custos dos processos de democracia direta. As sete questões são analisadas a partir de uma revisão bibliográfica que considera tanto fontes nacionais como internacionais. O estudo mostra que os processos de democracia direta podem ser um complemento para as instituições representativas em um sistema democrático. O bom desempenho dos plebiscitos, referendos e iniciativas populares depende tanto da regulamentação destes como também do desempenho das outras instituições políticas e da situação socioeconômica de um país. O estudo permite ampliar e aprofundar o debate sobre processos de democracia direta no Brasil

Rapid warming of the ocean around South Georgia, Southern Ocean, during the 20th century: Forcings, characteristics and implications for lower trophic levels

The Southern Ocean is known to have warmed considerably during the second half of the 20th century but there are few locations with data before the 1950s. In addition, assessments of change in this region are hampered by the strong seasonal bias in sampling, with the vast majority of data collected during the austral summer. However, oceanographic measurements near South Georgia span most of the last century, and we here consider almost year-round data from this location over an 81-year period (1925–2006). We observe significant warming between the early and late 20th century, with differential warming between summer and winter months and an indication that late 20th century summer temperatures peaked 6 days earlier. To quantify the longterm warming trend in this highly variable data, a mixed model utilising a Residual Maximum Likelihood (REML) method was used. Over the 81-year period, a mean increase of 0.9 1C in January and 2.3 1C in August was evident in the top 100m of the water column. Warming diminished below 100m and approached 0 at 200m. Thus the longterm warming around South Georgia is substantial—more so than documented previously for the circumpolar warming of the Southern Ocean. We examine potential causal effects of this trend, including local atmospheric and cryospheric change, the influence of upstreamwaters and the role of coupled modes of climate variability such as El Nin˜o/Southern Oscillation and the Southern Annular Mode (SAM). It is likely that all of these play a part in the observed temperature increase. However, the role of the SAM is strongly indicated, via its likely role in the circumpolar warming trend in the Southern Ocean, and also by the atypical response of the South Georgia region to changes in heat fluxes associated with the SAM. Furthermore, the combination of a regional decline in ice extent and strong upstream warming likely explains a significant part of the strong seasonal variation apparent in the warming trend. In addition, we consider the implications that long-term warming has for South Georgia’s lower trophic levels. For Euphausia superba, at their northern limit, we find a significant negative relationship between summer South Georgia water temperatures and mean summer density of E. superba across the southwest Atlantic sector of the Southern Ocean. Simple abundance and growth rate relationships with our long-term temperature data appear to show declining habitat suitability for E. superba. In contrast, the warming trend is likely to favour other macro- and mesozooplankton species that occupy the more northerly parts of the Antarctic Circumpolar Current, and it is likely to promote phytoplankton growth

Evidence for long-term averaging of Sr-87/Sr-86 in bovine enamel using TIMS and LA-MC-ICP-MS.

No abstract available