Chemical identification and optimization of the 4-aminophenol colorimetric test for the differentiation between hemp-type and marijuana-type cannabis plant samples

The 4- Aminophenol (4-AP) colorimetric test is a fast, easy-to-use, and cost-effective presumptive assay of cannabis plant material producing different chromophores with THC-rich cannabis (blue color) and with CBD-rich cannabis (pink color). The main drawback of the 4-AP test is a brief observation window where the color rapidly changes to black, limiting the utility of the test. We now report for the first time, the identification of the product chromophores between 4-AP and CBD/THC as well as propose an explanation and a solution for the color degradation of the chromophores. The identification of the chromophores is provided by spectroscopic (UV–Vis), chromatography, and mass spectrometry (TLC and LC-QToF-MS). Oxidation of excess 4-AP (Reagent A) in the presence of NaOH (Reagent B) produces the black color observed for the previously reported 4-AP tests and reported in the literature. The adjustment of reactants concentrations and volumes of 4-AP:THC/CBD to a 1:1 ratio significantly reduces the black oxidation by-product and increases the observation window up to 2 h instead of the previously reported 5–10 min. For the first time, mass spectrometry and chromatography confirmed that the reaction of THC and CBD with 4-AP produced chromophores with m/z (M + H) = 420, consistent with proposed indophenol structures. The TLC method developed confirmed the separation between CBD and THC chromophores. The specificity of the test is also reported, showing false positive results for the presence of THC (blue color) for samples of thyme and oregano. LDA and SIMCA models showed that the optimized 4-AP procedure performs better than the previously reported 4-AP color test.     

Evaluating the Accuracy of Cranial Indices in Ancestry Estimation Among South African Groups

Historically, population differences were quantified using cranial indices. Even though the application of indices is associated with numerous statistical and methodological problems, the use of cranial indices to estimate ancestry persists as demonstrated by its inclusion in several recent papers and conference presentations. The purpose of this study was to classify 207 South African crania and compare the results of five standard cranial indices to linear discriminant analysis (LDA). New sectioning points were created to contend with low classification accuracies (40–79%) and possible secular trends. Although the accuracies of the new sectioning points increased (66–87%), the accuracies associated with the stepwise LDA were higher (84%) and could classify the crania into one of the three South African groups. The results of the study demonstrate that indices cannot compete with multivariate techniques and should not be used in forensic anthropological analyses for ancestry estimation.     

Metric Sex Determination of the Human Coxal Bone on a Virtual Sample using Decision Trees

Decision trees provide an alternative to multivariate discriminant analysis, which is still the most commonly used in anthropometric studies. Our study analyzed the metric characterization of a recent virtual sample of 113 coxal bones using decision trees for sex determination. From 17 osteometric type I landmarks, a dataset was built with five classic distances traditionally reported in the literature and six new distances selected using the two-step ratio method. A ten-fold cross-validation was performed, and a decision tree was established on two subsamples (training and test sets). The decision tree established on the training set included three nodes and its application to the test set correctly classified 92% of individuals. This percentage was similar to the data of the literature. The usefulness of decision trees has been demonstrated in numerous fields. They have been already used in sex determination, body mass prediction, and ancestry estimation. This study shows another use of decision trees enabling simple and accurate sex determination.     

The Impact of Political Factors on Local Government Decentralisation

ABSTRACT

The process of local decentralisation of public services delivery has attracted research attention because of the wide range of factors that induce governments to make this decision. Nonetheless, most such studies have focused on economic and financial aspects, ignoring the impact of political factors. The scarce previous research about political factors is the motivation for this study. We used panel data models based on 153 Spanish municipalities with populations over 50,000 for the period 1999–2007. The process of decentralisation is disaggregated according to the legal form of the entities: corporations and foundations. Our results show that more corporatisation processes are carried out in environments where political competition is lower and the party in power enjoyed greater support in the last elections. Additionally, decentralisation processes usually take place in the years immediately following elections, especially through foundations. Furthermore, both forms of decentralisation are more likely to be initiated by right-wing politicians.     

Do Citizens Really Shop between Decentralised Jurisdictions? Tiebout and Internal Migration Revisited

Tiebout predicted that differences in service provision and tax rates across regions would lead citizens to migrate to their preferred jurisdiction. This central tenet of the fiscal federalism literature has rarely been explored outside the North American context. This paper delves into this gap in the literature by examining the factors that undermine Tiebout's prediction. It undertakes an international comparative analysis drawing upon recent innovations in the measurement of internal migration that facilitate country comparisons. While some of Tiebout's ideas find limited support, the overall weight of evidence suggests a weak link between internal migration and decentralisation     

Politólogos on the Run: Contrasting Paths to Internationalization of Southern Cone Political Scientists

Political scientists from the Southern Cone have enriched the discipline with pioneering work. Many of them went into exile for political reasons, and thus produced part of their work abroad. Although Latin American political science has professionalized since the 1980s, many scholars still emigrate for study and employment. Argentines most numerously seek academic careers abroad, while Brazil has many more domestic doctorates and returns home after doctoral studies abroad. Uruguayans emigrate in proportionally high numbers and tend to settle in Latin American countries, while the number of Chileans and Paraguayans abroad is minimal. These contrasting patterns are explained by reference to factors such as the availability of high‐quality doctoral courses, financing for postgraduate studies, and the absorptive capacity of national academic markets. Paradoxically, the size and performance of the diasporas may increase rather than reduce the visibility and impact of national political science communities.     

Comptes Rendus Book Reviews

This article follows the efforts of white settlers to impose cotton as an export crop in Natal and Zululand. Touted as a commodity capable of remaking land and life in the region in the 1850s, the 1860s, and again in the 1910s and 1920s, cotton never achieved more than marginal status in the region's agricultural economy. Its story is one of historical amnesia: although faith in the region's cotton prospects dipped following each spectacular failure, it was routinely resurrected once previous failures had been accounted for, or memories of them had faded.

Two crucial issues are at the centre of this episodic history. First, I explore the logistics of planned expansion, and the reasons for the repeated collapse of cotton-growing schemes. Second, I unravel the side effects of these difficult and disappointing efforts and argue that, despite repeated failure, cotton facilitated important structural changes to the region's agricultural, political and economic landscape.     

ETA: From secret army to social movement – the post‐Franco schism of the Basque nationalist movement

Under the Franco dictatorship, post‐Civil War generations of Basques grew up in a climate of physical violence and symbolic repression. Through the imposition of controls on all manifestations of Basque cultural and linguistic expression, the Spanish state transformed even the simplest of actions into defiant symbols of Basque identity. Rejecting, as ineffectual, attempts by the existing Basque Nationalist Party (PNV) to defend Basque culture, the more militant members of the PNV's youth organization attempted to stimulate a radical ethnic movement through a new organization, Euskadi ‘ta Askatasuna [Basque Homeland and Freedom (ETA)]. From its founding in 1959, ETA's principal goals have been the achievement of Basque independence and the revival of Basque culture and language. Its principal strategy has remained armed resistance to Spanish rule. To date, ETA has been responsible for approximately 600 deaths. In this article, we focus on the strategic and organizational evolution of ETA from secret army to social movement in the post‐Franco era. In particular, we seek to clarify the role that violence plays in the symbolic conflict of Basque/Spanish collective identities and to identify how the democratization process has influenced the strategies and tactics adopted by ETA as well as by those political organizations which have emerged from ETA and its numerous factions.