Phase separation in amino acid mixtures is governed by composition

Macromolecular phase separation has recently come to immense prominence as it is central to the formation of membraneless organelles, leading to a new paradigm of cellular organization. This type of phase transition, often termed liquid-liquid phase separation (LLPS), is mediated by molecular interactions between biomolecules, including nucleic acids and both ordered and disordered proteins. In the latter case, the separation between protein-dense and -dilute phases is often interpreted using models adapted from polymer theory. Specifically, the “stickers and spacers” model proposes that the formation of condensate-spanning networks in protein solutions originates from the interplay between two classes of residues and that the main determinants for phase separation are multivalency and sequence patterning. The duality of roles of stickers (aromatics like Phe and Tyr) and spacers (Gly and polar residues) may apply more broadly in protein-like mixtures, and the presence of these two types of components alone may suffice for LLPS to take place. In order to explore this hypothesis, we use atomistic molecular dynamics simulations of capped amino acid residues as a minimal model system. We study the behavior of pure amino acids in water for three types of residues corresponding to the spacer and sticker categories and of their multicomponent mixtures. In agreement with previous observations, we find that the spacer-type amino acids fail to phase separate on their own, while the sticker is prone to aggregation. However, ternary amino acid mixtures involving both types of amino acids phase separate into two phases that retain intermediate degrees of compaction and greater fluidity than sticker-only condensates. Our results suggest that LLPS is an emergent property of amino acid mixtures determined by composition.Financial support to D.D.S. comes from Eusko Jaurlaritza (Basque Government) through the project IT1254-19 and the Spanish Government through grants RYC-2016-19590 and PID2021-127907NB-I00 (MCIN/AEI/10.13039/501100011033/FEDER, UE). The author thanks Xabier López for useful discussions and Athi N. Naganathan and Robert B. Best for their comments on the manuscript. The author also acknowledges the staff at the DIPC Supercomputing Center for technical support

Choice of Metrics used in Collaborative Filtering and their Impact on Recommender Systems

The capacity of recommender systems to make correct predictions is essentially determined by the quality and suitability of the collaborative filtering that implements them. The common memory-based metrics are Pearson correlation and cosine, however, their use is not always the most appropriate or sufficiently justified. In this paper, we analyze these two metrics together with the less common mean squared difference (MSD) to discover their advantages and drawbacks in very important aspects such as the impact when introducing different values of k-neighborhoods, minimization of the MAE error, capacity to carry out a sufficient number of predictions, percentage of correct and incorrect predictions and behavior when attempting to recommend the n-best items. The paper lists the results and practical conclusions that have been obtained after carrying out a comparative study of the metrics based on 135 experiments on the MovieLens database of 100,000 ratios

Barriers and Motivators of Household Water-Conservation Behavior: A Bibliometric and Systematic Literature Review

Water scarcity, aggravated by growing demands, represents a significant challenge for humanity. Promoting household sustainable water-consumption behaviors has become vital. The Community-Based Social Marketing (CBSM) framework stands out among many strategies to promote water conservation. However, many interventions in this domain often neglect significant theoretical insights, leading to gaps in addressing key social and contextual drivers of behavior. This study conducts a systematic and bibliometric literature review aimed at identifying determinants underlying household water-conservation behaviors. This review encompasses 155 papers published from 1984 to early 2023. Our findings show that this is a highly multidisciplinary field of study with a marked increase in research attention discerned post-2010, particularly from water-stressed regions. Furthermore, our findings also reveal an often-overlooked integration of guiding theories and an over-reliance on self-reported measures in prior research. Factors such as attitude, perceived efficacy, emotions, and habits emerge as pivotal in understanding water conservation. However, while attitudes have been extensively analyzed in previous research, the other factors deserve greater attention from researchers. Inconsistencies in demographic predictors further hint at potential moderating roles. This paper offers valuable insights for designing effective household water-conservation interventions through a social marketing lens.This research was funded by Generalitat Valenciana (Emerging Project GV2022 number: CIGE/2022/051), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) doctoral research scholarship, and Universidad Católica de Córdoba (Argentina)

Mejora del acceso y la calidad de las infraestructuras educativas en la escuela de primaria de Baiwangué en la región de Guerá, Chad

El presente proyecto busca mejorar el acceso y las infraestructuras educativas de 19 escuelas de primaria identificadas por la contraparte con el fin de crear un modelo educativo de calidad en la región de Guéra en el Chad. Para ello, se va a basar en una de las 3 escuelas piloto identificadas por la contraparte, la escuela primaria de Baiwangué que cuenta con 261 alumnos y alumnas y un cuerpo docente de 5 personas. Se pretende conseguir una mejora de las infraestructuras así como favorecer la transferencia de conocimientos y tecnologías Sur-Norte y Norte-Sur entre todos los agentes implicados, en el marco de un programa de19 escuelas en toda la región

Alcohol regulation, communication strategies and underage alcohol consumption in Spain: Implications for social marketing

Purpose. The purpose of this paper is twofold. First, it examines the communication strategies pursued by firms related to alcohol beverages in Spain during a decade with major changes in alcohol marketing regulations. Second, it analyzes the relationship between these strategies and underage alcohol consumption before and after 2007. Design/methodology/approach. Panel data methodology is implemented using data from ESTUDES national survey (average sample size 26,000 interviews, 2004-2010) and INFOADEX (nationwide advertising expenditure, 1999-2013). Findings. The results show that, under a restrictive alcohol marketing framework, firms related to alcohol beverages adapt their communication strategies: budget deviation from advertising to sponsorship. Regarding alcohol quantity and frequency models, the relationship between alcohol advertising expenditure and underage alcohol consumption after 2007 is very small but still positive and significant. However, contrary to expectations, in the case of alcohol sponsorship, the relationship between expenditure and underage alcohol consumption has not been affected by the observed budget deviation from advertising to sponsorship after 2007. Research limitations/implications. Changes in alcohol advertising and sponsorship regulation lead firms related to alcohol beverages to change their communication strategies to overcome new regulatory restrictions and to reach their target group. Overall, despite the relationships between both advertising and sponsorship expenditure and underage alcohol consumption diminish between periods, they still remain positive and significant. Closer and updated monitoring of alcohol communication strategies pursued by firm is needed to keep controlling the alcohol advertising and sponsorship exposure to under age people. Originality/value. This is a pioneer study in analyzing communication strategies within the Spanish alcohol beverages sector and in proposing a model to analyze the dynamic effect of such strategies on underage alcohol consumption

Detection and identification of 'Candidatus Phytoplasma prunorum' in Prunus germoplasm

The molecular characterization of the causal agent of diseases associated with several symptoms such as decline, yellowing, leaf roll and off-season growth in stone fruits made it possible to determine a common etiology, and the name ´European stone fruit yellows´ phytoplasma was proposed. Recently, the new taxonomical species description within the genus is 'Candidatus Phytoplasma prunorum'.A 2-yr survey was carried out in two different Prunus collections of the Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA) including European and Japanese plum genotypes of various species and several interspecific hybrids used as rootstocks. Both off-season growth in winter and decline were observed. In order to identify the phytoplasma suspected as a causal agent, two different PCR methods were applied to all inspected trees. The first method was a nested PCR with 16Sr X group-specific primers followed by RFLP analysis. The second method was a direct PCR with specific primers for 'Ca P. prunorum' (Eca1/Eca2). In the most symptomatic trees the presence of this phytoplasma was confirmed by at least one of the methods; negative results were obtained in asymptomatic trees. The nested PCR-RFLPs analysis was confirmed as a reliable method for routinary diagnosis rather than direct PCR.La caracterización molecular del agente causante de enfermedades asociadas a varios síntomas, como el enrollamiento clorótico, anticipación de la floración y la brotación, leptonecrosis o amarillamiento en los frutales de hueso permitió determinar una etiología común, el fitoplasma 'European stone fruit yellows', recientemente clasificado taxonómicamente como 'Candidatus Phytoplasma prunorum'. Durante dos años se llevó a cabo una prospección en dos colecciones del Centro deInvestigación y Tecnología Agroalimentaria (CITA) de Aragón, que comprende diferentes especies e híbridos interespecíficos, de origen europeo y japonés, dentro del género Prunus. Se observaron síntomas de anticipo de floración y brotación en invierno y cierto decaimiento. Con objeto de identificar al posible fitoplasma causante de la enfermedad se aplicaron dos métodos en todos los árboles inspeccionados. El primero fue una PCR anidada con cebadores específicos del grupo 16Sr X seguida de un análisis de los fragmentos de restricción por RFLP. El segundo método fue una PCR con cebadores específicos de 'Ca P. prunorum' (Eca1/Eca2). En los árboles más sintomáticos se confirmó la presencia de los fitoplasmas por uno de los dos métodos, obteniéndose resultados negativos en los árboles asintomáticos. El primer método resultó ser más fiable que la PCR directa como método de diagnóstico rutinario