Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent. This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory. A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence. This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime. Recently, the operation of the high-intensity Relativistic Laser at the X-ray Free Electron Laser provided by the Helmholtz International Beamline for Extreme Fields has been inaugurated at the High Energy Density scientific instrument of the European X-ray Free Electron Laser. We make the case that this worldwide unique combination of an X-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision X-ray polarimetry, refinements of prospective discovery scenarios and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity.

We offer a novel motivational account of romantic love, which portrays it as a means to the end of feeling significant and worthy. According to the model, falling in love with a partner depends on the actor's perceptions that (1) the partner possesses meritorious characteristics, and (2) that they appreciate the actor and view them as significant. We assume that these two factors multiplicatively combine with the magnitude of actor's quest for significance to determine the likelihood of actor becoming enamored with partner. The multiplicative model has two major implications: 1. If any one of the partner's merit, appreciation, or actor's significance quest factors falls below its respective threshold of acceptability (such that it is subjectively non-existent), the likelihood of falling in love will be negligible. 2. Above their acceptability thresholds, levels of (partner's) merit, appreciation and (actor's) significance quest factors compensate for one another. A partner's lower standing on merit or appreciation is compensated in its impact on falling in love by the partner's higher standing on the remaining dimension. Furthermore, lower levels of either or both of these factors are compensated for by the actor's higher level of significance quest.

Our model affords a broad account of diverse love phenomena, allows the derivation of several specific hypotheses supported by prior close-relations research as well as new data, and it offers novel avenues for further research on classic issues in romantic love. The discussion considers our model's unique implications and examines its relation to other theories of love.

It is shown that an important distinction can be made between determinacy of common-factors and determinacy of unique-factors and that determinacy can be used as a criterion to establish a lower bound for the ratio of number of variables to number of factors necessary if specified levels of common- and unique-factor determinacy are to be attained.

It is shown that, under very general conditions, uniqueness estimates proposed independently by Guttman [1957] and by Harris [1963] provide tighter upper bounds on the unknown uniqueness values of factor analysis than do existing estimates.

Kaiser's measure of sampling adequacy is applied to a special Spearman matrix and a special q-cluster generalization. The result supports the contention that the measure should be no less than .5 for data to be appropriate for factor analysis.

This paper discusses and compares the methods of attitude scale construction of Thurstone (method of equal-appearing intervals), Likert (method of summated ratings), and Guttman (method of scale analysis), with special emphasis on the latter as one of the most recent and significant contributions to the field. Despite a certain lack of methodological precision, scale analysis provides a means of evaluating the uni-dimensionality of a set of items. If the criteria for uni-dimensionality are met, the interpretation of rank-order scores is made unambiguous, and efficiency of prediction from the set of items is maximized. The Guttman technique, however, provides no satisfactory means of selecting the original set of items for scale analysis. Preliminary studies indicated that both the Likert and the Thurstone methods tend to select scalable sets of items and that their functions in this respect are complementary. A method of combining the Likert and Thurstone methods in order to yield a highly scalable set of items is outlined. Sets of 14 items selected by the method have, in the two cases where the technique has been tried, yielded very satisfactory scalability.

Interpretations regarding the effects of exogenous and endogenous variables on endogenous variables in linear structural equation systems depend upon the convergence of a matrix power series. Convergence depends upon the eigenvalues of the structural coefficient matrix. The test for convergence developed by Jöreskog and Sörbom is shown to be only sufficient, not necessary and sufficient.

Female athletes are increasingly participating in sport during pregnancy and returning postpartum. However, similar to the Sex Data Gap in sport and exercise research(1), there is limited evidence to support athletes during this life stage(2) especially as it relates to nutrition. Therefore, as optimal nutrition is essential for long-term maternal and child health, the aim of this study was to investigate specific wants, needs and behaviours in relation to nutrition during pregnancy and postpartum return to sport in athletes.

King’s College London provided ethical approval (Ref: LRU/DP-23/24-41676) and the study was pre-registered (https://doi.org/10.17605/OSF.IO/NCSZK). An exploratory cross-sectional online survey is being conducted and dissemination is occurring during April and May 2024. Primary variables are assessed using researcher developed and validated measures and included pregnancy and postpartum nutritional support needs, supplement use, athlete level, performance changes and sociodemographic characteristics. Residents of the UK or ROI, ≥ 18 years old, trained and/or competed as an athlete prior to and/or during pregnancy within the last eight years are eligible. All data was summarised using IBM SPSS Statistics. Due to the exploratory nature of the survey, preliminary descriptive evidence is shown and comparisons between groups (e.g. athlete level, region, number of pregnancies) will be presented.

35 eligible athletes (UK: 24 (68.6%); ROI: 11 (31.4%)) from 14 team and individual sports have completed the survey. Average age of participants was 34.2±3.2 and 32 (91.4%) had ≥1 child. 9 participants (25.7%) were currently pregnant, and 7 (20%) had retired due to pregnancy. Only 9 participants (25.7%) received any nutrition advice during pregnancy, and, of the postpartum participants, one participant (3.8%) received nutrition advice during the postpartum period. During pregnancy, participants reported wanting to receive advice from NHS Midwives, Obstetricians and Gynaecologists (37.7%) and fellow athletes who’ve previously experienced pregnancy (21%).

Whereas postpartum advice was preferable from NHS Midwives, Obstetricians and Gynaecologists (37.1%), sports-specific nutritionist/dietitian (37.1%) and general

nutritionist/dietitian (37.1%). During pregnancy, 28 participants (80%) reported wanting athletespecific nutrition advice related training needs during pregnancy and 19 participants (54.3%) reported wanting more information about pregnancy-specific supplement intake (e.g. folic acid). Postpartum, 22 participants (62.9%) reported wanting athlete-specific nutrition advice related training needs during postpartum and returning to sport and 20 participants (57.1%) reported wanting more information about breast or mixed feeding. The top listed challenges to returning to sport postpartum were childcare provisions (94.3%), infant feeding practices (85.7%) and sleep (82.9%).

The preliminary findings revealed that pregnant/postpartum athletes want further advice in areas such as nutrition advice specific to being an athlete and training during pregnancy and postpartum, pregnancy supplement intake, and infant feeding practices. These areas require further investigation so pregnant and postpartum athlete needs can be better met.

Background: After a transient ischemic attack (TIA) or minor stroke, the long-term risk of subsequent stroke is uncertain. Methods: Electronic databases were searched for observational studies reporting subsequent stroke during a minimum follow-up of 1 year in patients with TIA or minor stroke. Unpublished data on number of stroke events and exact person-time at risk contributed by all patients during discrete time intervals of follow-up were requested from the authors of included studies. This information was used to calculate the incidence of stroke in individual studies, and results across studies were pooled using random-effects meta-analysis. Results: Fifteen independent cohorts involving 129794 patients were included in the analysis. The pooled incidence rate of subsequent stroke per 100 person-years was 6.4 events in the first year and 2.0 events in the second through tenth years, with cumulative incidences of 14% at 5 years and 21% at 10 years. Based on 10 studies with information available on fatal stroke, the pooled case fatality rate of subsequent stroke was 9.5% (95% CI, 5.9 – 13.8). Conclusions: One in five patients is expected to experience a subsequent stroke within 10 years after a TIA or minor stroke, with every tenth patient expected to die from their subsequent stroke.

OBJECTIVES/GOALS: We aimed to conduct an updated genome-wide meta-analysis of keloids in expanded populations, including those most afflicted by keloids. Our overall objective was to improve understanding of keloid development though the identification and further characterization of keloid-associated genes with genetically predicted gene expression (GPGE). METHODS/STUDY POPULATION: We used publicly available summary statistics from several large-scale DNA biobanks, including the UK Biobank, FinnGen, and Biobank Japan. We also leveraged data from the Million Veterans Program and performed genome-wide association studies of keloids in BioVU and eMERGE. For each of these datasets, cases were determined from ICD-9/ICD-10 codes and phecodes. With these data we conducted fixed effects meta-analysis, both across ancestries and stratified by broad ancestry groups. This approach allowed us to consider cumulative evidence for genetic risk factors for keloids and explore potential ancestry-specific components of risk. We used FUMA for functional annotation of results and LDSC to estimate ancestry-specific heritability. We performed GPGE analysis using S-PrediXcan with GTEx v8 tissues. RESULTS/ANTICIPATED RESULTS: We detected 30 (23 novel) genomic risk loci in the cross-ancestry analysis. Major risk loci were broadly consistent between ancestries, with variable effects. Keloid heritability estimates from LDSC were 6%, 21%, and 34% for European, East Asian, and African ancestry, respectively. The top hit (P = 1.7e-77) in the cross-ancestry analysis was at a replicated variant (rs10863683) located downstream of LINC01705. GPGE analysis identified an association between decreased risk of keloids and increased expression of LINC01705 in fibroblasts (P = 3.6e10-20), which are important in wound healing. The top hit in the African-ancestry analysis (P = 5.5e-31) was a novel variant (rs34647667) in a conserved region downstream of ITGA11. ITGA11 encodes a collagen receptor and was previously associated with uterine fibroids. DISCUSSION/SIGNIFICANCE: This work significantly increases the yield of discoveries from keloid genetic association studies, describing both common and ancestry-specific effects. Stark differences in heritability support a potential adaptive origin for keloid disparities. Further work will continue to examine keloids in the broader context of other fibrotic diseases.

Understanding the distribution and habitat requirements of species is crucial for designing conservation actions, yet this information is not available for many plant species. We report the first confirmed wild populations of Porroglossum parsonsii, which, because of its horticultural value, is commercialized in national and international markets, from where it was first described to science. Our large-scale survey of 341 10 × 30 m plots spanning Andean forests, paramo habitats and pasturelands in Colombia suggests that P. parsonsii has a restricted geographical distribution in Andean forests with high forest cover (71.4–86.2%), where it occurs in low numbers (5–17 individuals per plot). Because of its market value (USD 18–20 per plant) there is a risk the species could be collected illegally, and therefore the habitat of the species in the Santuario de Fauna y Flora de Iguaque requires appropriate conservation.

End members and species defined with permissible ranges of composition are presented for the true micas, the brittle micas and the interlayer-cation-deficient micas. The determination of the crystallochemical formula for different available chemical data is outlined, and a system of modifiers and suffixes is given to allow the expression of unusual chemical substitutions or polytypic stacking arrangements. Tables of mica synonyms, varieties, ill-defined materials and a list of names formerly or erroneously used for micas are presented. The Mica Subcommittee was appointed by the Commission on New Minerals and Mineral Names (“Commission”) of the International Mineralogical Association (IMA). The definitions and recommendations presented were approved by the Commission.