The archaeological site known as “El Faro” is located in the upper Gulf of California region of the Baja California peninsula. Archaeological work within this area of Baja California has been limited, and the investigation presented in this article is the most extensive to date in the region. This research, combining surface reconnaissance with three eld seasons of excavation, has yielded data that allow for the reconstruction of the subsistence patterns of the site’s inhabitants through time. Additionally, we have been able to establish that the late occupation inhabitants of the El Faro site had a system of exchange with neighboring Yuman regions. The subsistence and trade evidence together allows us to comment on the proposed isolation and marginalization of the prehistoric groups in Baja California.

The development of treatment biomarkers for psychiatric disorders has been challenging, particularly for heterogeneous neurodevelopmental conditions such as attention-deficit/hyperactivity disorder (ADHD). Promising findings are also rarely translated into clinical practice, especially with regard to treatment decisions and development of novel treatments. Despite this slow progress, the available neuroimaging, electrophysiological (EEG) and genetic literature provides a solid foundation for biomarker discovery. This article gives an updated review of promising treatment biomarkers for ADHD which may enhance personalized medicine and novel treatment development. The available literature points to promising pre-treatment profiles predicting efficacy of various pharmacological and non-pharmacological treatments for ADHD. These candidate predictive biomarkers, particularly those based on low-cost and non-invasive EEG assessments, show promise for the future stratification of patients to specific treatments. Studies with repeated biomarker assessments further show that different treatments produce distinct changes in brain profiles, which track treatment-related clinical improvements. These candidate monitoring/response biomarkers may aid future monitoring of treatment effects and point to mechanistic targets for novel treatments, such as neurotherapies. Nevertheless, existing research does not support any immediate clinical applications of treatment biomarkers for ADHD. Key barriers are the paucity of replications and external validations, the use of small and homogeneous samples of predominantly White children, and practical limitations, including the cost and technical requirements of biomarker assessments and their unknown feasibility and acceptability for people with ADHD. We conclude with a discussion of future directions and methodological changes to promote clinical translation and enhance personalized treatment decisions for diverse groups of individuals with ADHD.

Previous studies have associated attention-deficit/hyperactivity disorder (ADHD) with several alterations in electroencephalographic (EEG) activity. Time-frequency analyses capturing event-related power modulations are becoming an increasingly popular approach, but a systematic synthesis of the time-frequency literature in ADHD is currently lacking. We conducted the first systematic review and meta-analysis of time-frequency studies of children and adults with ADHD in comparison to neurotypical controls. Searches via Medline, Embase, and Web of Science, as well as reference lists, identified 28 eligible articles published until March 2021. Of these, 13 articles with relevant data were included in a multi-level meta-analysis. Most studies examined power modulations of alpha, theta and/or beta frequencies (N = 21/28), and focused on children (N = 17/28). Meta-analyses showed significantly weaker theta increases (Cohen's d = -0.25, p = 0.039; N_ADHD = 346, N_CONTROL = 327), alpha decreases (d = 0.44, p < 0.001; N_ADHD = 564, N_CONTROL = 450), and beta increases (Cohen's d = -0.33, p < 0.001; N_ADHD = 222, N_CONTROL = 263) in individuals with ADHD relative to controls. These patterns indicate broad brain-oscillatory alterations in individuals with ADHD with small (theta) and small-to-moderate (alpha and beta) effect sizes. These group differences were partly consistent when repeating analyses by age group (<18 and 18+ years) and task type (cognitive control, working memory, and simple attention tasks). Overall, our findings identify widespread event-related brain-oscillatory alterations in individuals with ADHD during a range of neurocognitive functions. Future research requires larger samples, a broader range of frequency bands (including delta and gamma) during a wider type of cognitive-affective processes, and should clarify whether atypical event-related power profiles are ADHD-specific or shared with other neuropsychiatric conditions.

The X-ray fluorescence analysis of obsidian artifacts from four study areas in Baja California, Mexico, suggests regional and local patterning in the geological sources used by indigenous hunter-gatherers during the late prehistoric and colonial periods. Obsidian artifacts were typically made from materials from the closest geological source, creating a distinct north-south pattern of obsidian distribution. In the northern region of Baja California, this pattern appears to correspond to ethnographically-documented language boundaries. However, within each study area, particular sites exhibit higher degrees of obsidian source diversity than others—a pattern that may suggest chronological or social variation in access to particular obsidian sources. Unexpectedly, projectile points do not exhibit noticeably higher levels of source diversity when compared to an aggregate of all other obsidian artifacts. Together, these patterns offer a baseline of knowledge about regional obsidian distributions and point toward potential avenues for future research on obsidian availability and conveyance in Baja California.

Gas-phase lanthanide-SO2 complexes, Ln(CH3SO2)3(SO2)-, were produced by collision induced dissociation (CID) of Ln(CH3SO2)4- precursors prepared by electrospray ionization. For all lanthanides except Eu, CID of Ln(CH3SO2)4- resulted in CH3 loss to form Ln(CH3SO2)3(SO2)-, which spontaneously react with O2 to form Ln(CH3SO2)3(O2)-. CID of Eu(CH3SO2)4- produced only Eu(CH3SO2)3-, with reduction from Eu(III) to Eu(II). For Ln = Yb and Sm, the Ln(CH3SO2)4- underwent neutral ligand loss to form Ln(CH3SO2)3-, which reacted with O2 to yield Ln(CH3SO2)3(O2)-, recovering the Ln(III) oxidation state. The CID results show parallels to condensed-phase Ln3+/Ln2+ redox chemistry. Density functional theory (DFT) calculations on Ln(CH3SO2)3(SO2)- for Ln = La, Yb and Lu reveal that SO2 acts as a bidentate oxygen bound ligand for doublet ground-state La(CH3SO2)3(SO2)- and Lu(CH3SO2)3(SO2)-, while the ground state for Yb(CH3SO2)3(SO2)- is an open-shell singlet with a monodentate SO2 ligand. Loss of CH3 is computed to be much more favorable than neutral ligand loss for La(CH3SO2)4- and Lu(CH3SO2)4-, whereas both channels are comparable in energy for Yb(CH3SO2)4-, in accord with the experiments. DFT results for fragmentation of Cu(CH3SO2)2- reveal that formation of the organometallic complex, Cu(CH3SO2)(CH3)-, is energetically most favorable, in agreement with contrasting fragmentation pathways of copper and lanthanide complexes.

OBJECTIVE: ADHD is a prevalent neurodevelopmental disorder characterized by symptoms of inattention and hyperactivity-impulsivity. Impairments in executive functioning (EF) are central to models of ADHD, while alpha-band spectral power event-related decreases (ERD) have emerged as a putative electroencephalography (EEG) biomarker of EF in ADHD. Little is known about the roles of EF and alpha ERD and their interactions with symptoms of ADHD. METHOD: We estimated network models of ADHD symptoms and integrated alpha ERD measures into the symptom network. RESULTS: EF emerges as a bridge network node connecting alpha ERD and the hyperactivity/impulsivity and inattention symptoms. We found that EF most closely relates to a subset of symptoms, namely the motoric symptoms, seat (difficulty staying seated), and runs (running or climbing excessively). CONCLUSIONS: EF functions as a bridge node connecting alpha ERD and the ADHD symptom network. Motoric-type symptoms and EF deficits may constitute important nodes in the interplay between behavior/symptoms, cognition, and neurophysiological markers of ADHD.