Discovery of EDA-Complex Photocatalyzed Reactions Using Multidimensional Image Processing: Iminophosphorane Synthesis as a Case Study

Herein, we report a multidimensional screening strategy for the discovery of EDA-complex photocatalyzed reactions using only photographic devices (webcam, cellphone) and TLC analysis. An algorithm was designed to identify automatically EDA-complex reactive mixtures in solution from digital image processing in a 96-wells microplate and by TLC-analysis. The code highlights the region of absorption of the mixture in the visible spectrum, and the quantity of the color change through grayscale values. Furthermore, the code identifies automatically the blurs on the TLC plate and classifies the mixture as colorimetric reactions, non-reactive or potentially reactive EDA mixtures. This strategy allowed us to discover and then optimize a new EDA-mediated approach for obtaining iminophosphoranes in up to 90% yield.

Diseño y análisis psicométrico de una escala para evaluar riesgo suicida en adolescentes argentinos

Design and psychometric analysis of a suicide risk scale for Argentinean adolescents and young people Abstract: Suicidal behavior in adolescents and youth has become a public health issue which requires improving the available scales in order to enable the early detection of risk cases. Therefore, for this purpose, this study presents the design and psychometric analysis of the Argentinean Scale of Suicidality for Adolescents (EASA-I by its Spanish acronym) Screening. It measures a specific dimension of suicidal ideation and five risk factors: low self-esteem, negative perspective of the future, low emotion regulation, difficulties in problem-solving and lack of social support. This study was aimed at analyzing content construct and face validity, as well as convergent and discriminant validity evidence with external measures. Internal consistency of the scores was also examined. The sample was composed of 291 adolescents and young adults. Results suggest that the EASA-I constitutes a short and simple scale with adequate psychometric properties suitable to be used in different areas of application and research. Keywords: adolescents; youth; suicide risk; multidimensional assessment; screening. Resumen: Los comportamientos suicidas en la adolescencia y la juventud constituyen un problema de salud pública que exige mejorar las herramientas de evaluación disponibles, de cara a detectar precozmente casos en riesgo. Se presenta el diseño y análisis psicométrico de la Escala Argentina de Suicidalidad para Adolescentes EASA-I Screening. Su objetivo reside en la medición de una dimensión específica, i.e., la ideación suicida, más cinco factores de riesgo: baja autoestima, perspectiva negativa del futuro, baja regulación emocional, dificultades para la resolución de problemas y falta de apoyo social. Basándonos en una muestra de 291 adolescentes y jóvenes, se analizaron evidencias de validez de contenido, aparente y de constructo, así como de validez convergente y discriminante con medidas externas. Se examinó, además, la consistencia interna de las puntuaciones obtenidas. Los resultados indican que la EASA-I posee adecuadas propiedades técnicas para su uso en población local en diferentes ámbitos de aplicación e investigación. Palabras clave: adolescentes; jóvenes; riesgo suicida; evaluación multidimensional; screening.

Discovery of gramicidin A analogues with altered activities by multidimensional screening of a one-bead-one-compound library

Gramicidin A (1) is a peptide antibiotic that disrupts the transmembrane ion concentration gradient by forming an ion channel in a lipid bilayer. Although long used clinically, it is limited to topical application because of its strong hemolytic activity and mammalian cytotoxicity, likely arising from the common ion transport mechanism. Here we report an integrated high-throughput strategy for discovering analogues of 1 with altered biological activity profiles. The 4096 analogue structures are designed to maintain the charge-neutral, hydrophobic, and channel forming properties of 1. Synthesis of the analogues, tandem mass spectrometry sequencing, and 3 microscale screenings enable us to identify 10 representative analogues. Re-synthesis and detailed functional evaluations find that all 10 analogues share a similar ion channel function, but have different cytotoxic, hemolytic, and antibacterial activities. Our large-scale structure-activity relationship studies reveal the feasibility of developing analogues of 1 that selectively induce toxicity toward target organisms.

Designing Pricing Strategy for Operational and Technological Transformation

We examine how operational or technological transformation impacts consumer value, as well as the effectiveness of a firm’s pricing strategies. We develop a model of multidimensional screening featuring forward-looking consumers who make short-run consumption and long-run purchase decisions. Using a detailed panel of consumer data from a rental-by-mail firm, we estimate consumer utility for current consumption, obtaining heterogeneous preferences for bunching and smoothing consumption. Using counterfactual analysis, we evaluate the impact of improving service time. We find that the firm with improved service time might create more value for all consumers, but its profits and even revenues could diminish because value extraction becomes more difficult. We find a novel mechanism that causes this effect, which is driven by increased consumer heterogeneity in the valuation for each product and reduced differentiation across products. This result persists even when the firm can reoptimize its price levels based on the service time. We find that a change in the pricing strategy might be required for the firm to obtain higher revenue with improved service time. This paper was accepted by Matthew Shum, marketing.

The development of multidimensional screening model of geriatric syndrome for community-dwelling older adults: results of the Taiwan Integration Health and Welfare (TIHW) Study

Background: Comprehensive geriatric assessment (CGA) is a multidimensional and multidisciplinary diagnostic and treatment process that identifies geriatric syndrome in older adults. However, CGA program is not appropriate in community screening. To the best of our knowledge, there is no applicable multidimensional screening model to evaluate geriatric syndrome in community-dwelling older adults. This study aimed to identify the risk factors of geriatric syndrome among physical function tests, socioeconomic status, medical history, and healthy behaviours in community-dwelling older adults and develop a multidimensional prediction model for community screening. Methods: A total of 1313 community-dwelling older adults aged 60 years or above were recruited from 58 communities in four aging cities in Taiwan. Geriatric syndrome was defined by disability using Instrumental Activities of Daily Livings, cognitive impairment using Short Portable Mental Status Questionnaire, depression using Geriatric Depression Scale, or by receiving mild disability card. The cutoff values of the physical function tests were calculated using receiver operating characteristic analysis. Multivariate logistic regression was used to evaluate the risk factors of geriatric syndrome, and the risk model was developed using stepwise logistic regression. Results: We developed the new cutoff values in predicting geriatric syndrome for dominant handgrip strength test, 6-meter walk, and timed up-and-go tests, which were significantly associated with geriatric syndrome. Moreover, male sex, obesity, absence of labour activities, and participants who cannot report personal information, had depressive mood for the past 2 weeks, and a history of heart disease were associated with geriatric syndrome. Finally, we developed Taiwan Risk Scores for Geriatric Syndrome (TRSGS) with the cutoff value of 6 (sensitivity, 77.2%; specificity, 75.5%). Conclusions: Most of the screening tools focus on specific problems such as sarcopenia, dementia, or frailty. The TRSGS model demonstrated a multidimensional prediction model, which could be applied in community screening for geriatric syndrome. Management of risk factors to prevent geriatric syndrome in the community is important.

Screening in Contract Design: Evidence from the ACA Health Insurance Exchanges

We study insurers’ use of prescription drug formularies to screen consumers in the ACA Health Insurance exchanges. We begin by showing that exchange risk adjustment and reinsurance succeed in neutralizing selection incentives for most, but not all, consumer types. A minority of consumers, identifiable by demand for particular classes of prescription drugs, are predictably unprofitable. We then show that contract features relating to these drugs are distorted in a manner consistent with multidimensional screening. The empirical findings support a long theoretical literature examining how insurance contracts offered in equilibrium can fail to optimally trade off risk protection and moral hazard. (JEL D82, G22, H51, I13, I18)