Detection of Mitragynine in Mitragyna Speciosa (Kratom) Using Surface-Enhanced Raman Spectroscopy with Handheld Devices

A simple, quick, selective, sensitive, and effective field-friendly method capable of being used by nonexperts has been developed for detecting mitragynine in Mitragyna speciosa (kratom) using surface-enhanced Raman spectroscopy (SERS). Over 100 samples and blanks (known to be either positive or negative for the presence of mitragynine) were examined in duplicate using five identical handheld Raman spectrometers, which provided a data set of over 1,000 examinations. Based on the results of these analyses, the method yielded a true-positive rate of 99.3%, a true-negative rate of 97.9%, a false-positive rate of 2.1%, and a false-negative rate of 0.7%. The average minimum detectable concentration (C_m) of mitragynine that reproducibly yielded a match for one of the library spectra on all five instruments was determined to be 342 ng/mL (ppb). This C_m value is a conservative estimate considering that the extraction process was not fully optimized by this study, which was not necessary since the C_m value achieved was well below typical mitragynine concentrations in kratom (1.3–2.3%). The method is ideal (i) for prioritizing samples for additional testing using other more time-consuming laboratory-based techniques needed to detect and quantify mitragynine and (ii) for field use at international mail facility (IMF) satellite laboratories to help interdict kratom and prevent this dangerous product from reaching the U.S. supply chain.     

Evaluating the Effects of Repeated Psychological Injury: an Introduction to the Special Issue

Psychological Injury and Law -     

Back to the Future: The Pulling Apart of our Towns and Cities

Growing divisions between Britain’s towns and cities have created a dilemma for the Labour Party in seeking to represent very different parts of the country. There are some who argue that Labour must choose the global networked youth—who largely reside in cities—in order to maximise its electoral chances. This is an argument that defies electoral gravity and fails to address the root causes of the gulf between towns and cities. As jobs and investment have gone into cities, many towns have seen the local population age and local economies become unsustainable. In both towns and cities there is a clamour for power to move closer to home and for the renewal of democratic institutions, offering Labour the chance to win power and end the divisions that have come to characterise British politics.     

Physiologic Responses to Racial Rejection Images Among Young Adults from African-American Backgrounds

Physiologic reactivity to racially rejecting images was assessed in 35 young adults (10 males, 25 female) from African-American backgrounds using the startle probe paradigm. In a laboratory setting, participants viewed 16 images depicting racial rejection, racial acceptance, nonracial negative, and nonracial positive themes. While viewing these images, startling bursts of noise were presented and the magnitude of the eyeblink responses were measured. Results supported an attentional mechanism which suggests that, while viewing both racially rejecting and nonracial positive images, individuals may be so absorbed in processing the images that they appear less distracted by the startling noise. However, these patterns were only found for participants low in racial regard. Young adults who felt positively about their racial background did not exhibit differential processing of startle stimuli as a function of slide themes. Race-rejection sensitivity did not moderate startle reactivity. Developmental implications, particularly in light of coping with racial discrimination, are discussed.

Correction to: Age Patterns in Risk Taking Across the World

Journal of Youth and Adolescence - In the original publication, the legends for Figs 4 and 5 were incorrect, such that each regression line was mislabeled with the incorrect country. Below are the...