Search

Early into the COVID-19 pandemic, MillerBlumstein (2020) outlined a theoretical research program (TRP) oriented around themes of contagion control and containment, legal amnesty, system leniency, nonenforcement, and tele-justice. Here, two and a half years later, these lingering themes are revisited to advocate for empirical research informing criminal justice system reform. The pandemic created rare natural experiment research conditions that enable unique and potentially valuable insights on necessitated innovations that may indicate future justice practices and policies. Given the sweeping effects of the shutdown, examples are numerous ranging from staffing analyses to estimate agencies' personnel needs to ensure that basic public safety functions can be met after early retirements and resignations from virus risk and anti-police sentiment, the use of virtual communication in various legal proceedings at arrest, incarceration, and release junctures, and, especially, the risks versus benefits of early release. In addition to better identifying who should be jailed pre-trial, prioritization of calls for service, triaging of court cases, and hygiene and sanitation issues within facilities are other important examples central to a COVID and crime TRP. Attending research could demonstrate the utility of normative operations and identify shortfalls to be addressed during anomic conditions prior to another shutdown or similar event and present, through comparison of innovative and traditional derived outcomes, system reform and improvement opportunities. By seizing upon rare data made possible by natural experimental COVID generated conditions, researchers can meaningfully investigate the ongoing applicability of justice system adaptations mandated by the pandemic in terms of effectiveness and efficiency toward the interrelated goals of evidence-based practice discovery and justice reform.

PurposePolice misconduct is a grave matter undermining public trust in law enforcement and police professionalism. While research has specified major forms and causal theories of police misconduct, especially regarding corruption and excessive force, scientific attention to police sexual misconduct (PSM) has been more limited and is addressed here. The purpose of this paper is to address this issue.Design/methodology/approachThe current study was commissioned to examine PSM incidents (n = 50) between 2000 and 2009 in a large, metropolitan, police department in the USA. Data were extracted from agency internal affairs case files, personnel records and disciplinary histories for involved officers.FindingsAnalyses identified common factors and trends across officers, complainants and sexual misconduct events that were dichotomized per case substantiation and observed on a severity continuum from unobtrusive to criminal conduct.Originality/valueThough findings did not evidence a deviant subculture often implicated in the police literature, specific opportunities to reduce officer misconduct, including intensifying administrative sanctioning and other perceptual deterrence measures, were identified.

Introduction The THN3 randomized, controlled trial of moderate to severe obstructive sleep apnea (OSA) showed that proximal (“targeted”) hypoglossal nerve stimulation (HGNS) safely improved sleep-disordered breathing (SDB) and quality of life (QOL) through 11 months of treatment. Outcomes of subjects receiving active proximal HGNS also surpassed those with inactive therapy 4 months post-implant. Herein 3-year outcomes of THN3 are reported and compared to distal HGNS (STAR trial). Methods THN3 OSA subjects (Apnea-Hypopnea Index, AHI, 20-65/hr; BMI ≤ 35 kg/m2, no drug-induced sleep endoscopy screening) were followed long-term. Complete data through 3-year follow-up were analyzed. Efficacy measures comprised AHI, Oxygen Desaturation Index (ODI), %sleep time O2 saturation < 90% (T90), Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ) EQ-5D Visual Analog Scale (VAS) and Snore Outcomes Survey (SOS). 36-Month medians were compared against those after 11 months of therapy (Month 12/15) and with STAR. Adverse events (AEs) during Months 12-36 for THN3 and STAR were also compared. Results 75% of THN3 participants (104/138) attended 3-year follow-up, with complete efficacy records in N≥93 except for SOS (N=67, not administered at all sites). Proximal HGNS produced clinically and statistically significant improvements in SDB and QOL at Month 12/15 that were closely maintained at 36 Months (median paired changes at Month 36 from Baseline/Month 12/15: □AHI:-18.2/-0.1, □ODI:-16.2/0.8, □T90:-1.8/0.2, □FOSQ:3.0/0.0, □ESS:-5.0/0.0, □VAS:5.0/0.0, □SOS:37.5/3.1) and were comparable to STAR at 36 Months (□AHI:-19.4, □ODI:-17.2, □T90:-1.5, □FOSQ: 2.6, □ESS:-4.0). Procedure- and device-related AEs respectively totaled (3 and 27)/(4 and 122) in THN3/STAR over Months 12-36. During this time, 3 severe related-AEs occurred in THN3; the most frequent related AEs involved tongue discomfort (N=8, device-related). Conclusion Improvements in sleep apnea and QOL on proximal HGNS at Month 12/15 persisted through at least Month 36. Proximal HGNS long-term efficacy was comparable to distal HGNS. AEs occurred uncommonly during long-term follow-up and were typically mild. Proximal HGNS is a safe, effective, stable, long-term therapy, yielding comparable improvements to distal HGNS in treating moderate to severe OSA. Results of the ongoing, confirmatory OSPREY randomized controlled trial will provide additional insights into therapeutic benefits of proximal HGNS. Support (if any) LivaNova

The novel corona virus COVID-19 has become a worldwide public health pandemic that has induced anomic conditions impacting daily routines. COVID-19 response measures specifically alter regular schedules and both restrict and expand opportunities for various types of crime while presenting unprecedented challenges for the criminal justice system. For criminologists and criminal justice scientists, the virus also presents natural experiment conditions allowing for real-world theory tests and observation of the relative effectiveness of practice and policy options under weighty conditions. Toward synthesizing scientific discourse and forthcoming empirical work, we suggest the benefits of a COVID-19 crime and justice research program and offer some anchoring concepts. Contagion, containment measures (social distancing, facemasks, shelter-in-place, economic shutdown, virtual work and schooling, banned group gatherings), and social ordinance compliance (voluntary or enforced) posture a conceptual framework from which to align research on crime, justice, and victimization during the virus. After observing crime trends and justice system challenges, we suggest how the pandemic presents opportunities for review of various criminal justice, especially incarceration, policies. System change is a recurring theme across this special issue of the American Journal of Criminal Justice that features twenty additional contributions from a wide range of authoritative crime and justice scholars. These articles on traditional crime during the virus, virus specific hate crime and domestic violence, and the challenges posed by COVID-19 to law enforcement, the courts, and corrections will hopefully provide initial commentary toward deeper inquiry.

PurposeThis study aims to advance the existing analytic model to include staff allocation information at the district level. Maintaining adequate size of staff is essential to law enforcement agencies' ability to ensure social order, fight crime and, increasingly, deliver a widening range of social services. Review of the scientific literature on police size of force and staffing calculation models indicates that this line of inquiry (i.e. manpower analysis) is attentive to population size and workload demands but generally inattentive to how service demands are affected by community-level variables. Current staffing calculation models specify number of staff needed for a jurisdiction but do not inform the allocation of personnel across districts within the jurisdiction.Design/methodology/approachTo address this problem, the current study illustrates an enhanced analytic model to provide law enforcement staffing recommendations for a southern coastal county. An integrated per capita-workload manpower analysis model first factors the minimum number of law enforcement deputies needed per population size served and recent history workload demands and then executes the six-step workload model process. This study enhances staffing analysis by adding an additional seventh arithmetical step indicating the staffing needs by districts across a jurisdiction.FindingsThe results from the integrated per capita-workload analysis indicate the need to hire additional deputies to meet current and future demands.Originality/valueDiscussion centers on the need to include drivers of police services identified but not measured in this study's application of the hybrid manpower analysis model and its replication potential.

Introduction THN3 was the first reported parallel-arm, randomized controlled trial (RCT) of hypoglossal nerve stimulation (HGNS), wherein targeted HGNS (THN) was shown to be safe and efficacious at ameliorating sleep disordered breathing in patients with moderate to severe OSA and BMI≤35kg/m2 without screening with drug-induced sleep endoscopy. Unique among reported HGNS trials, separate cohorts of patients receiving early and late THN were followed longitudinally. Methods Measurements of apnea-hypopnea index (AHI) were available Pre-enrollment, Baseline (2 nights), Month 4 and Month 12/15. Except for Pre-enrollment, AHI values were calculated by an independent core laboratory from polysomnographic recordings. All subjects with complete data were included for analysis. AHI trajectories were constructed for early and late THN activation (Treatment[T], N=83, Month 1 and Control[C], N=45, Month 4, respectively) by computing median values. Confidence intervals were calculated by bootstrapping each median (N=30,000). Patient-reported outcome measures (PROMs) were treated similarly. Results AHI (Median (95% CI)) trajectories demonstrated a consistent pattern of pre-implant alignment (Pre-enrollment T:39.1 (36.0-45.0), C:38.0 (32.0-41.0); Baseline 1 T:36.1 (33.0-39.9), C:31.3 (27.2-38.6); Baseline 2 T:37.0 (34.3-41.0), C:35.2 (32.3-38.2)), divergence at the conclusion of the randomization period (Month 4 T:15.6 (11.9-25.3), C:30.6 (23.7-38.6)) and reconvergence following 11 months of treatment (Month 12/15 T:20.7 (16.0-26.4), C:18.1 (16.3-23.3)). Non-standardized Pre-enrollment AHI was slightly higher than Baseline values. Trajectories were similar for oxygen desaturation index (Baseline 1 T:35.3 (31.9-38.0),C:34.3 (27.5-40.3); Baseline 2 T:37.1 (33.4-39.3),C:36.8 (33.9-38.3); Month 4 T:19.5 (16.2-28.5), C:33.8 (25.4-41.1); Month 12/15 T:19.5 (16.0-25.6), C:19.7 (16.3-26.0)), the Epworth Sleepiness Scale (Baseline T:11.0 (10.0-13.0),C:11.5 (8.5-14.0); Month 4 T:6.0 (5.0-7.0), C:11.5 (8.0-12.5); Month 12/15 T:6.0 (4.0-7.0), C:5.5 (4.5-6.0)), the Functional Outcomes of Sleep Questionnaire (Baseline T:15.3 (14.0-16.5),C:14.7 (13.3-16.6); Month 4 T:18.3 (17.7-18.8), C:16.7 (14.9-17.7); Month 12/15 T:18.8 (18.3-19.3), C:18.5 (17.5-19.5)) and the Snore Outcomes Survey (Baseline T:26.6 (21.9-31.3),C:21.9 (18.8-31.3); Month 4 T:60.9 (56.3-67.9), C:29.7 (23.4-42.9); Month 12/15 T:62.5 (59.4-68.8), C:68.8 (62.5-71.9)). Conclusion Group trajectories of sleep-disordered breathing and PROMs further demonstrate the robust effects of THN in patients with moderate to severe OSA and the value of parallel-arm RCTs. Similar results may be expected in the ongoing OSPREY confirmatory trial of THN. Support (If Any) LivaNova

An increase in correctional treatment programming options coupled with prison population reduction legislation has driven a widespread transfer of supervision from prisons to community corrections. As a result, medium-to-high risk offenders with substance use needs are increasingly managed through community-based supervision programs such as intensive supervision probation (ISP). ISP programs frequently rely on different types of graduated sanctions to encourage program completion. To further develop research on how graduated sanctions should be applied in response to substance-use-related violations, this study examines whether enhanced treatment sanctions (a rehabilitative approach) and jail sanctions (a punitive approach) may differentially impact successful ISP completion. Using a sample of persons who committed a substance use violation while on ISP, results from multilevel models demonstrate that enhanced treatment sanctions are significantly associated with increased odds of successful ISP completion. On the other hand, jail is not significant, and enhanced treatment and jail do not interact to influence ISP program success. Due to the deleterious nature of the jail environment, findings call into question the utility of jail sanctions on ISP outcomes. Overall, enhanced treatment may be a preferable means through which to sanction probationers and parolees who commit substance-use-related violations while under community supervision.

Introduction THN3 was the first reported parallel-arm, randomized controlled trial of hypoglossal nerve stimulation (HGNS), wherein targeted HGNS (THN) was shown to be safe and efficacious at ameliorating sleep disordered breathing in selected patients with moderate to severe OSA and BMI≤35kg/m2 without screening with drug-induced sleep endoscopy. A secondary THN3 objective was to identify baseline characteristics which enhance therapeutic response. Methods Predictors of long-term (Month 12/15) apnea-hypopnea index (AHI) response (reduction ≥50% to ≤20/hr) were identified in stages. Baseline characteristics, including polysomnography parameters, were screened one at a time using univariate logistic regression. Variables significant at α=0.25 were further selected using stepwise multivariate logistic regression. Candidate predictors were then optimized by manual, incremental threshold adjustment to maximize AHI response rate (RR). Optimized predictors were ranked according to the AHI RR and size of the corresponding subpopulation, with a goal of capturing at least 40% of the overall THN3 cohort. Results Baseline sleep efficiency (SE) in the normal range (>85%) achieved the highest AHI RR while retaining 42% (58/138) of the THN3 cohort. Similar to the overall study population, subgroup subjects were predominantly middle-aged (age 54±7 years), male (83%), Caucasian (86%) and overweight/obese (BMI 30±3 kg/m2). Short-term (Month 4) AHI RRs in the Treatment and Control groups were 59.5% and 20.0%, respectively, with long-term AHI RR at 50.9%. Median AHI was reduced from 35.1 to 16.0, as compared to 29.3 to 9.0 in the STAR trial of distal HGNS. ODI RRs (reduction ≥25%) for Treatment and Control were respectively 73.0% and 30.0% at Month 4 and 64.9% at Month12/15. Enhanced response carried through to larger point estimates for improvement in secondary variables, including the Epworth Sleepiness Scale and the Functional Outcomes of Sleep Questionnaire, exceeding minimum clinically important differences thresholds of 2-3 and 1.7-2.0, respectively. Conclusion Normal SE at Baseline was associated with enhanced AHI and ODI RR as well as patient-reported outcome measures for patients receiving THN therapy, providing results similar to those obtained with distal HGNS. Future studies, including the ongoing OSPREY trial, will be needed to prospectively validate these findings. Support (If Any) LivaNova

A density-depleted region ("gap") is known to exist between water and hydrophobic surfaces. Using X-ray reflectivity, we have observed similar gaps between hydrophobic self-assembled monolayers (SAMs) and four other polar liquids. For these liquids and for water, the observed electron density depletion is nonzero and is in most cases slightly greater than the depletion attributable to the layer of hydrogen atoms at the SAM surface. On the other hand, the observed X-ray reflectivity from the interfaces between SAMs and three nonpolar liquids studied can be explained either without gaps or with smaller gaps. Thus, polar liquids (including but not limited to water) stand away from even the terminal hydrogen atoms at hydrophobic surfaces, while nonpolar liquids interpenetrate the terminal region. There is no consistent correlation between the sizes of the gaps and the liquid-SAM contact angles, the relative polarities of the polar liquids, or their bulk densities.

Although exit interviews are common in business and educational contexts, they are utilized less frequently in the criminal justice system. This is unfortunate, however, as exit interviews can aler...

Widespread implementation of offender reentry programming has increased justice program evaluations but few have featured research designs sufficiently rigorous to optimally inform policy. Program evaluations typically neglect program fidelity concerns to focus on outcome analysis that seldom feature optimal spuriousness reduction. The current study, the second component of a mixed-method design evidencing fidelity, presents the methods and outcome findings for the Delaware County Transition (DCT) Program, an Ohio jail-based crimesolutions.gov endorsed treatment intervention for dually diagnosed offenders. Review of the reentry and dual-diagnosis literature provides a background for description of the DCT program and methods employed to observe programming effects. Findings indicated DCT participation was associated with overall recidivism reductions and time to recidivism and orient discussion around related rehabilitative modalities.

Novel and emerging psychoactive drugs (NEPDs), a research-based classification referencing a wide range of natural plant-derived substances and synthetic compounds, have garnered considerable acade...

Federal funding efforts have increased the number of reentry programs over the past decade with corresponding evaluations of these initiatives. Reentry programming targets a wide range of offenders though most have focused on medium and high-risk individuals with substance abuse and/or mental health disorders. This research note provides a profile overview of two programs in central Ohio funded by the Second Chance Act and offers a summary of process and outcome evaluation findings from both initiatives. Results from a mixed methods research design suggested that the programs were largely successful in terms of reducing recidivism among participants, though issues related to programmatic fidelity were also identified. While these programs pre-date more current offender intervention efforts, such as the Justice Mental Health Collaboration Program, identified barriers to program success reaffirm the saliency of longstanding problems embedded in and challenged by correctional and police culture.

Introduction and Aims Acetyl fentanyl, a fentanyl analogue emerging onto the recreational drug scene, has been responsible for numerous recent fatal overdoses in the USA, Europe and Russia. Studies reporting acetyl fentanyl use are presently limited to case studies and mortality reports. This study explores the nature of acetyl fentanyl use through the collection of first-hand qualitative data from users to inform public health and drug control policy responses. Design and Methods A series of focus group interviews within a correctional setting—Delaware County (Ohio) Jail, USA. Participants were 102 individuals in one of two US Bureau of Justice Assistance Second Chance Act substance use treatment initiatives participating in at least one focus group session. Five of these individuals reported acetyl fentanyl use. Semi-structured qualitative focus group sessions queried subjects' drugs of choice and nature of drug use. Responses were explored through follow-up organic discourse. Results Acetyl fentanyl users were generally unaware that they had administered the substance until after use (initially believing that they were administering heroin). They described the effects of acetyl fentanyl as stronger and qualitatively different from heroin. These individuals showed no interest in using acetyl fentanyl again describing it as unpleasant and more risky, both because of potency and the threat of a ‘bad batch’. Discussion and Conclusions Acetyl fentanyl is reaching heroin users, some of which administer it unknowingly. Regulation of acetyl fentanyl is recommended in all countries as is increasing public awareness that the substance is distinct from and being sold as heroin. [Miller JM, Stogner JM, Miller BL, Blough S. Exploring synthetic heroin: Accounts of acetyl fentanyl use from a sample of dually diagnosed drug offenders. Drug Alcohol Rev 2018;37:121–127]

The interfacial structure of the room temperature ionic liquid methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([MTOA]+[NTF2]−) near a silicon electrode was investigated using specular X-ray reflectivity. Using this technique, we have previously observed “crowding”, i.e., formation of a thick anion layer on a positively charged electrode. We now report that this layer develops over time scales in the range ∼400–1100 s. This is different from the time scales reported in other experiments, and is inconsistent with most theoretical predictions. A tentative explanation is proposed which assumes that the formation and dispersion of the crowding layer requires collective reordering of anions/cations through the electrochemical cell. We suggest that because of the presence of multiple time scales in these systems, the observed time scales will vary depending on the time scale of the measurement.

As a supplemental component of a larger confidential analysis of police sexual misconduct (PSM) in “Central City”, this study examines news accounts of PSM events in seven comparable metropolitan cities in the United States. Google search was used to identify media news reports to estimate PSM, standardized for city population and size of police force. Findings indicate that PSM rates vary by city, events typically implicate a male officer and a female victim, and most media reports involved an arrest that may signal under-reporting. Observation of commonalities across the sample cities informs discussion of the need for transparency and preventative measures.

Novel psychoactive drugs (NPDs), an emerging class of dangerous substances, generally mimic the actions of commonly abused substances such as marijuana, stimulants, hallucinogens, and opiates, but are formulated, marketed, and used either to sidestep legal restrictions or to avoid positive drug screens. Synthetic cannabinoids such as Spice and K2 along with synthetic stimulants often referred to as “bath salts” have recently entered U.S. markets. The current study explores the relationship between being arrested and using NPDs per self-report survey data obtained from 2,349 students at a large university in the Southeastern United States. Respondents indicated whether they had used synthetic psychoactive drugs, reported demographic characteristics, and whether they had been arrested for a number of offenses. Results from logistic regression and propensity score matching models indicate that those who have been arrested are also more likely to use NPDs.

Few crime topics elicit as much fear and concern as child abduction, which is also commonly known as child kidnapping. Child abduction, or kidnapping, is a criminal offense that entails the wrongful taking of a minor by force or violence, manipulation or fraud, or persuasion. There are basically two types of child abduction; familial-parental and the much-exaggerated stranger abductor. Parental abductions are heavily contextualized in child custody and involve far less physical danger to child victims than stranger abductions, which include the majority of violence and sexual violence associated with more extreme abduction events. Despite the popular culture myth of “abduction waves” and pedophiles lurking in the shadows, child abduction is actually a rare phenomenon, as indicated by Shutt, et al. 2004 (cited under Social Constructions), which likened abduction likelihood to the rarity of a lightning strike. Nonetheless, media hype and sensationalism have framed both popular culture and social-legal constructions of abduction frequency, risk, and offender and victim stereotypes, most notably stranger/pedophile abductors and abduction epidemics. The extant academic literature on child abduction can be observed as a three-pronged typology of 1) historical works, more so accounts of well-known US child kidnappings such as the Lindbergh baby, Adam Walsh, and, more recently, Elizabeth Smart, and international research on abduction for ransom, custody, vice work, and military servitude; 2) legal overviews and opinions, both domestically and internationally, with the latter especially focused on abduction legislation initiatives within Hague Conference; and 3) the focus of this article, empirical scientific works primarily appearing in refereed journal articles. The majority of this literature originates from the behavioral (psychology) and social sciences (criminology and criminal justice, sociology, and political science) and, to a lesser degree, from professional school orientations (social work, nursing, and public health). As a rare event and relatively myopic, though seriously consequential, phenomenon, there isn’t a discernable number of reference works, anthologies, or established published bibliographies informing the child abduction knowledge base. Fortunately, there is a sizeable body of empirical works on child abduction to characterize the nature of the offense, its perpetrator and victim participants, and responses by juvenile and criminal justice as well as other stakeholder agencies. While substantial research attention has addressed child abduction in Africa, Latin America, and parts of Europe, this coverage is based on American research over the last few decades. This empirical literature on child abduction is presented in annotated form as a thematic taxonomy comprised of the following: 1) General Overviews, 2) Offense, Offender, and Victim Characteristics, 3) Familial Abduction, 4) Stranger Abduction, 5) Awareness and Prevention, 6) AMBER Alert and Other Official Responses, and 7) Social Constructions.

Slither.io is a massively multiplayer online game in which up to 500 players control worm-like avatars and consume food to grow with the goal of becoming the largest player while avoiding running into one another. The platform serves as a good testbed for developing AI controlled agents due to its accessibility, mechanical simplicity, and unpredictability. In this paper, we develop a Slither.io bot using neuroevolution of augmenting topologies (NEAT) and compare its performance to that of the best open source bot available online (a high-performing expert system bot). With a fitness function based on the final size of the agent, our results show steady improvement in average score. We discuss the unique emergent behaviors observed by our top performing agents.

Project Panoptyk is a game engine designed to run Massive Multiplayer Online (MMO) games with information creation, sharing, and exchange as the central gameplay focus. This engine is a work in progress, intended to serve as a platform for simulating human/robot interaction, as well as automatic generation of game assets, quests, and real-estate. The project also aims to create an open platform allowing indie and research communities to experiment with MMO concepts. In pursuit of these goals, we identify and address a number of challenges that have traditionally made it difficult for independent designers or researchers to be competitive in creation of new MMO games.

In this paper, we seek to identify game design paradigms that enhance the player experience for multiplayer games in regards to engagement and immersion through social group dynamic emphasized level design based on peer presence. In order to identify these paradigms, we developed a 2D platform game consisting of several scenarios designed to invoke different sub-categories of peer presence social group dynamics such as group cohesion, peer pressure, leader-observer social identity role distribution and black sheep effects. We argue that risk and reward core game mechanics can be carried out or reinforced by the social group dynamics phenomena. A group of participants was monitored through gameplay, and administered surveys prior to, as well as following the game experience.Our study successfully found game design patterns which highlight specific behaviors within group dynamics, especially group cohesion and time-sensitive decision making with regards to peer pressure, which, compared to the single-player control group, increase players engagement and immersion during multiplayer gameplay. Our investigations into these player behavior patterns aim to help game designers enhance player experience in multiplayer games.

Many aspects of game jams have been studied as their popularity continues to grow. Their lingering effects on learning, motivation, and social interaction has been documented over the years. In this paper, we observe the immediate effects game jams have on participant confidence in game making skills, and preparedness, as they change over the course of the jam. We conduct surveys on three different jams held from 2016 to 2019. We collect a total of 107 surveys with 26 full sets (subjects) for the confidence questions and 17 for the preparedness. By surveying participants each day at three different game jams, we observe a consistent trend of positive change in their confidence and preparedness. Our results suggest game jams have an immediate positive influence on participants' confidence and sense of preparedness in making games, and this should be studied further.

Rare earths, which are fundamental components of modern technologies, are often extracted from aqueous solutions using surfactants at oil-water interfaces. Heavier lanthanides are more easily extracted, even though all lanthanides are chemically very similar. Using x-ray fluorescence measurements and theoretical arguments, we show that there is a sharp bulk-concentration-dependent transition in the interfacial adsorption of cations from aqueous solutions containing Er^{3+} or Nd^{3+} in contact with a floating monolayer. The threshold bulk concentration of erbium (Z=68) is an order of magnitude lower than that of neodymium (Z=60), and erbium is preferentially adsorbed when the solution contains both ions. This implies that elemental selectivity during separation originates at the surfactant interface. Electrostatic effects arising from the interface dielectric mismatch, ionic correlations, and sizes of the ions explain the sharp adsorption curve and selectivity.