Coexistence of a native and an invasive mussel species across an environmental gradient: Do interactions matter?

Introductions of invasive species are increasing worldwide, potentially threatening biodiversity. Although invasive species often displace native species by outcompeting them, coexistence between native and non-native species is common in diverse communities. A field experiment investigated the interactions between the native mussel Mytilus galloprovincialis and the invasive black pygmy mussel Xenostrobus securis across an environmental salinity gradient in the Ria de Vigo (NW Spain). The salinity gradient strongly affected the physiological responses of both mussel species as well as the competitive interactions between the two species. Mytilus galloprovincialis had a stronger effect on the invader than vice versa. The competition with M. galloprovincialis and the release from predation in certain estuarine areas may in part explain the dynamics of the invader population in the Ría de Vigo. Furthermore, results suggest that the invader may contribute positively to ecosystem functioning by increasing bentho-pelagic coupling, water-column clearance, and biodeposition of organic material in the innermost parts of estuaries, where it reaches large abundances. These areas are likely to promote and maintain the supply of propagules to the outermost parts, as well as favouring secondary spread along the Galician coast.Ministerio de Economía y Competitividad | Ref. CGL2014-60193-PXunta de Galicia | Ref. ED431C 2021/4

Benchmarking meta-analytical conceptualizations of B2B seller skills against empirical evidence in services firms

Purpose The purpose of the study was to benchmark meta-analytical conceptualizations of business-to-business (B2B) seller skills against empirical evidence in services firms. Design/methodology/approach The study is based on a deductive approach and questionnaire survey focusing on a range of services firms from different industries and corporate sizes. A total of 389 questionnaires out of 732 were returned, generating a response rate of 53.1%. Findings The study aims to provide empirical evidence and structures relating to B2B sellers' capabilities in a seven-dimensional conceptualization, all of which can be used in services firms to improve their seller efficiency. Each seller skill dimension performs a different function in the sales services process. Research limitations/implications The authors conclude that the verified meta-analytical conceptualizations of B2B seller skills seem valid and reliable in services firms. Nevertheless, further research needs to be carried out, based on other company characteristics as well as industries. Practical implications It reduces the risk perceived by customers in B2B services settings through cultivating the sellers' capabilities, based on the seven-dimensional evidence of seller skills to enhance sales performance. Originality/value The study contributes to existing theory and previous studies by offering a foundation on which to structure sales performance indicators in services firms. Specifically, it contributes to structuring B2B seller skills across a selection of principal dimensions in B2B services settings

The direct effect of B2B sellers' skills on relative and absolute sales performance: a dual measurement approach

Purpose The purpose of this paper is to test the direct effect of B2B sellers' skills on relative and absolute sales performance. Design/methodology/approach Based on a questionnaire survey and deductive approach. A total of 236 useable questionnaires out of 315 are returned, generating a response rate of 74.9%. Findings Only one out of twelve hypothesized relationships in the research model of the direct effect of B2B sellers' skills on relative and absolute sales performance turned out to be significant. Research limitations/implications Indicate that the researchers’ current understanding of the effect of sales performance indicators on sales performance, based on B2B sellers' skills, is narrow and simplistic. Practical implications Results indicate that there are skills other than the tested ones (i.e. interpersonal, adaptiveness and selling-related knowledge), that can have direct effects on B2B sellers' relative and absolute sales performance. Originality/value Sheds light on the ambiguous direct effect of B2B sellers' skills on sales performance and the almost non-existent direct effect on B2B sellers' relative and absolute sales performance

Sites Web éducatifs pour enseigner la dynamique relativiste au niveau secondaire et universitaire

Esta investigación realiza una revisión del enfoque adoptado para enseñar la dinámica relativista por distintos sitios y páginas webs educativas orientadas al nivel secundario y universitario. Las webs se analizan por medio de una categorización inductiva, que tiene variables relativamente similares a las que resultan de un análisis de los libros escolares utilizados para enseñar la TER (González, et. al., 2022). El trabajo evidencia que las webs desarrolladas por instituciones de educación formal tales como ministerios de educación o universidades, poseen un enfoque similar a los libros de texto, es decir que trasladan el saber de los libros hacia las webs. Por otro lado, en los sitios web orientados a la enseñanza secundaria, la vía principal a la dinámica relativista es el concepto de masa y energía, partiendo de cuestionar las leyes de Newton, mientras que en las webs universitarias se parte del concepto de momentum y de las leyes de conservación. El trabajo formula algunas consideraciones didácticas sobre la enseñanza de la dinámica relativista en la escuela.This research reviews the approach adopted to teach relativistic dynamics by different educational websites aimed at secondary and university levels. The websites are analyzed through an inductive categorization, which has variables relatively similar to those resulting from an analysis of the school textbooks used to teach TER (González et al., 2022). This research shows that websites developed by formal education institutions such as ministries of education or universities have a similar focus to textbooks, meaning they transfer knowledge from books to the web. On the other hand, in websites oriented toward secondary education, the primary way to relativistic dynamics is the concept of mass and energy, starting by questioning Newton’s laws, while university websites begin with the concept of momentum and conservation laws. This research formulates some didactic considerations regarding the teaching of relativistic dynamics in schools.Cette recherche examine l’approche adoptée pour enseigner la dynamique relativiste sur différents sites web éducatifs destinés aux niveaux secondaire et universitaire. Les sites web sont analysés au moyen d’une catégorisation inductive, qui présente des variables relativement similaires à celles résultant d’une analyse des manuels scolaires utilisés pour enseigner la TER (González et al., 2022). Le travail montre que les sites web développés par des institutions d’éducation formelle telles que les ministères de l’éducation ou les universités ont une approche similaire à celle des manuels, c’est-àdire qu’ils transfèrent les connaissances des livres vers le web. D’autre part, sur les sites web orientés vers l’enseignement secondaire, la principale approche de la dynamique relativiste est le concept de masse et d’énergie, en remettant en question les lois de Newton, tandis que sur les sites web universitaires, on part du concept de quantité de mouvement et des lois de conservation. Le travail formule quelques considérations didactiques concernant l’enseignement de la dynamique relativiste à l’école.Fil: Gonzalez, Richard. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Núcleo de Investigación en Educacion Ciencia y Tecnologia; ArgentinaFil: Otero, Maria Rita. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Núcleo de Investigación en Educacion Ciencia y Tecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Arlego, M.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Núcleo de Investigación en Educacion Ciencia y Tecnologia; Argentin

Action and social alignment constituents of collaboration in B2B relationships: buyer and seller perspectives

Purpose To test a research model consisting of hypothesized relationships within and between the domains of action and social alignment based on buyer and seller perspectives in B2B relationships. Design/Methodology/Approach Based on two cross-industrial samples of 218 buyer B2B relationships and 208 seller B2B relationships in Taiwan. Findings Findings relate to the dual facets of the domain of membership theory. Cooperation represents more likely intangible and subjective interests of alignment, and coordination represents more likely tangible and objective actions of alignment, in buyer and seller B2B relationships. Research limitations/Implications Validates a research model of action and social alignment in the context of buyer and seller B2B relationships. Contributes to comparing buyer and seller perspectives in relation to existing theory and previous studies on quality constructs in B2B relationships. Offers suggestions for further research. Managerial Implications Practitioners in B2B settings need to focus on joint actions as well as joint interests, and vice versa, as the economic and non-economic satisfaction of a business relationship complement each other. Originality/Value Validates the research model of action and social alignment in the context of buyer and seller B2B relationships. Provides multiple contributions to existing theory and previous studies of relationship quality based on buyer and seller perspectives in B2B setting

Pretreatment of plastic waste: Removal of colorants from hdpe using biosolvents

UIDB/50011/2020 UIDP/50011/2020 CA18220, 2020.00647.CEECIND UIDB/50006/2020 UIDP/50006/2020Plastics recycling remains a challenge due to the relatively low quality of the recycled material, since most of the developed recycling processes cannot deal with the additives present in the plastic matrix, so the recycled products end up in lower-grade applications. The application of volatile organic solvents for additives removal is the preferred choice. In this study, pretreatment of plastic packaging waste to remove additives using biosolvents was investigated. The plastic waste used was high-density polyethylene (HDPE) with blue and orange colorants (pigment and/or dye). The first step was to identify the type of colorants present in the HDPE, and we found that both plastics presented only one colorant that was actually a pigment. Then, limonene, a renewable solvent, was used to solubilize HDPE. After HDPE dissolution, a wide range of alcohols (mono-, di-, and tri-alcohols) was evaluated as antisolvents in order to selectively precipitate the polymer and maximize its purity. The use of limonene as solvent for plastic dissolution, in combination with poly-alcohols with an intermediate alkyl chain length and a large number of hydroxyl (OH) groups, was found to work best as an antisolvent (1,2,3-propanetriol and 1,2,4-butanetriol), leading to a removal of up to 94% and 100% of the blue and orange pigments, respectively. Finally, three cycles of extraction were carried out, proving the capability of the solvent and antisolvent to be recovered and reused, ensuring the economic viability and sustainability of the process. This pretreatment provides a secondary source of raw materials and revenue for the recycling process, which may lead to an increase in the quality of recycled polymers, contributing to the development of an economical and sustainable recycling process.publishersversionpublishe