The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence

Becoming a candidate for mental health care: a mixed methods investigation of how the process of seeking care contributes to persistent mental health disparities experienced by youth of color

This mixed methods study sought to refine the causal explanations for racial disparities in mental health care by exploring with youth of color (YOC, ages 12–21) how they became candidates for psychiatric care (“candidacy”). The thesis focused on developing and testing hypotheses about the Candidacy Model (CM) as a mediator of the relationships between mental health needs, racism, and health care utilization; examining those relationships when the candidate for care was represented by an agent; and characterizing how YOC and their agents experienced the assertion and adjudication stages of CM during a psychiatric emergency services visit. Despite a rich and growing literature on patient and environmental factors associated with lower access to psychiatric services, health services research in the United States has paid little attention to how YOC actualize their candidacy for mental health services. The CM suggests that vulnerable populations must negotiate with health care systems to have their needs considered medically treatable and to experience treatment in conditions that are congruent with their lifestyles. Theorizing that CM acts as a mediator between healthcare needs, racism, and treatment, this thesis explored how the specific stages of CM influenced mental health outcomes for YOC. The hypothesized relationships between candidacy, needs, racism, and utilization were tested using data from two national surveys, and in two different contexts: among young adults (ages 18-21) and among adolescents (ages 12–17) whose candidacy was co-constructed with their guardians. Through qualitative research (interviews and observation), over two years the research team explored with YOC and their guardians how current and prior candidacy experience influenced their use of psychiatric emergency services, an undesirable source of mental health care, and often the last resort for patients unable to access ongoing care. I found limited evidence that CM stages mediated the relationship between health care needs and treatment. Experiencing racism decreased the likelihood of being a successful candidate for care. Explorations with YOC and guardians found that people of color were marginalized when their assertions were ignored and when they were excluded from mental health care decision making. Repeat visits to the psychiatric emergency room reflected a negotiation strategy, in which the YOC and guardian triangulate and learn over time how to negotiate for a desired outcome. This thesis deepens knowledge of CM and of the role of negotiations in mental health care access for YOC, providing theoretical insights that will inform interventions to improve mental health equity.2025-08-23T00:00:00

DNA Barcoding and Its Potentials for the Genetic Identification of Grapevine Cultivars.

Vitis vinifera L., with more than 14,000 cultivars in existence on worldwide-scale plantations, is one of society's most important agricultural crops with broad genetic variability. The difficulty in recognizing grapevine varieties based on ampelographical traits and secondary metabolites prompted the development of molecular markers suitable for determining genetic diversity distribution and achieving genetic varietal identification, thus ridding numerous cases of synonymy and homonymy. In the present work, we propose a single-copy nuclear DNA barcoding approach combined with a character-based system with the aim of reconstructing cultivar-specific haplotypes to be exploited as a new diagnostic assay of grapevine accessions. A total of 159 V. vinifera genotypes were analyzed on the basis of five nuclear coding regions, namely the GAI, ATP synthase and UFGT genes along with two ESTs. The sequencing of barcode regions enabled the discovery of discriminant SNPs (1/34 bp) and the reconstruction of 134 distinct haplotypes. Most of the haplotypes were cultivar-specific, and only a few haplotypes were shared by more, although strictly related, cultivars. Overall, the technique was successful for inferring haplotypes suitable for the identification of cultivars and also useful for corroborating some hypotheses regarding the origin of local cultivars, suggesting several issues of misidentification (synonymy/homonymy)