Bridging the spatiotemporal gap in Diazotroph activity and diversity with high-resolution measurements

The biological fixation of dinitrogen (N2) by marine microbes called “diazotrophs” sustains ∼50% new production in the ocean, boosting CO2 absorption by photoautotrophs and thus contributing to the mitigation of climate change. New environmental conditions sustaining N2 fixation have been revealed in recent years, enabling more accurate forecasting of future nitrogen inputs and localized hot spots. However, at present the paucity and biased geographical coverage of N2 fixation and diazotroph diversity measurements impede attempts to reconcile global nitrogen budgets with observed rates. Most studies have been conducted at disparate spatiotemporal scales, including: (i) discrete and short duration measurements in small seawater volumes isolated from the environment, and (ii) spatial extrapolations and global models of diazotrophy projected over decades to centuries. We argue that this knowledge gap lies at the fine scales: dynamic seawater structures < 200 km wide and < 2 months lifetime. However, the spatiotemporal resolution of conventional oceanographic cruises, with stations separated by tens to hundreds of kilometers, is too poor to resolve fine scale processes. Bridging this gap requires leveraging high spatiotemporal resolution measurements. Here we present and discuss the advantages and disadvantages of contemporary methods and equipment able to provide high-resolution measurements at sea. We also provide insights into high-resolution sampling approaches to be developed in the near future. Increasing the spatiotemporal resolution of diazotroph activity and diversity will provide more realistic quantifications of nitrogen fluxes in the dynamic ocean

The role of human resource management in transferring knowledge through and joint venture

Cada vez más, el entorno exige a las empresas que sean más flexibles y capaces de responder a los cambios que se produzcan en él, la adquisición y utilización de nuevo conocimiento puede ser un recurso crítico para responder de forma adecuada a estos cambios. Ésto ha dado lugar a la aparición de la sociedad del conocimiento, la cual impone nuevas exigencias a las organizaciones (Claver y Zaragoza, 2007). La ventaja competitiva se asienta cada vez más en activos estratégicos, como lo es el conocimiento y los recursos que son necesarios para su gestión y transferencia. Una eficaz transferencia de conocimiento requiere como principal facilitador la puesta en marcha de prácticas de recursos humanos que la faciliten entre los miembros implicados. De forma particular, facilitar reuniones y encuentros entre el personal, diseñar espacios para que las personas puedan reunirse de manera informal e intercambiar ideas y compartir conocimiento. La creación y desarrollo de alianzas estratégicas en general, y de joint venture, en particular, fuerza a los altos directivos a preparar informes para los máximos ejecutivos de la compañía y a reunirse con los distintos directores de alianzas y jefes de proyectos. La relación que surge entre ellos obliga a compartir la información general sobre el funcionamiento de la cooperación y sobre las prácticas de RRHH que dan mejores resultados. De hecho, la transferencia de nuevo conocimiento es el producto de una interacción dinámica entre los trabajadores del conocimiento en sus tres roles: empleados de base, directivos medios y altos directivos. Las hipótesis se contrastan mediante un modelo de ecuaciones estructurales, analizando una muestra compuesta por 74 empresas (51 empresas españolas, y 23 del resto del mundo). Hemos revisado la literatura relacionada con este tema y no hemos encontrado muchos estudios empíricos que traten sobre ello.In an increasingly demanding environment that requires firms to be more flexible and able to respond to the changes that take place, the acquisition and use of new knowledge can be a critical resource for providing an adequate response to these changes. This situation has paved the way for the appearance of a knowledge-based society, which imposes new demands on organizations (Claver and Zaragoza, 2007). Competitive advantage is increasingly based on strategic assets, such as knowledge and resources that are necessary to manage and transfer it. Efficient transfer of knowledge requires as a main enabler, introducing human resource practices that give the members involved access to this knowledge. In particular, arranging meetings between staff, designing spaces so that people can meet informally and exchange ideas and share knowledge, and efficiency in generating knowledge requires skill from individuals in particular knowledge areas The creation and development of strategic alliances in general, and joint ventures in particular, oblige top managers to prepare reports for companies’ CEOs and meet different managers from alliances and project heads. The relationship that arises obliges them to share general information on the functioning of the firm and on HR practices that give the best results. In fact, the transfer of new knowledge is the product of a dynamic interaction between knowledge workers in their three roles: 1. normal employees, 2. mid-level managers and 3 top level managers. The hypotheses were contrasted via a structural equation model using a sample of 74 firms, 51 of which were Spanish and 23 from the rest of the world, which had recently cooperated in a joint venture. We carried out an in-depth review of the literature whioch revealed that few studies have either theoretically or empirically address this question

Deep into oceanic N₂ fixation

International audienc

Dissolved organic matter uptake by <i>Trichodesmium </i>in the Southwest Pacific

International audienceThe globally distributed diazotroph Trichodesmium contributes importantly to nitrogen inputs in the oligotrophic oceans. Sites of dissolved organic matter (DOM) accumulation could promote the mixotrophic nutrition of Trichodesmium when inorganic nutrients are scarce. Nano-scale secondary ion mass spectrometry (nanoSIMS) analyses of individual trichomes sampled in the South Pacific Ocean, showed significant 13 C-enrichments after incubation with either 13 C-labeled carbohydrates or amino acids. These results suggest that DOM could be directly taken up by Trichodesmium or primarily consumed by heterotrophic epibiont bacteria that ultimately transfer reduced DOM compounds to their host trichomes. Although the addition of carbohydrates or amino acids did not significantly affect bulk N 2 fixation rates, N 2 fixation was enhanced by amino acids in individual colonies of Trichodesmium. We discuss the ecological advantages of DOM use by Trichodesmium as an alternative to autotrophic nutrition in oligotrophic open ocean waters. Nitrogen is recognized as the proximate limiting nutrient for primary production in the oceans 1. The oceanic nitrogen reservoir is controlled by a balance between fixed nitrogen gains (via dinitrogen-N 2-fixation) and losses (denitrification) 2. While global nitrogen budget estimations determine that denitrification exceeds N 2 fixation considerably 3 , recent improvements in the 15 N 2 isotope tracer method used to measure biological N 2 fixation have evidenced that formerly published rates could be underestimated by a factor of ~2 to 6 4–8 , and thus could be high enough to balance denitrification on a global basis. However, the variability among N 2 fixation rates obtained when using the two different methods (adding 15 N 2 as a bubble or pre-dissolved in seawater) 4,9 can be high 7 and at times not significant 10–12. A mechanistic understanding of which factors determine the degree of discrepancy between the two 15 N 2 methods is currently lacking. Moreover, marine pelagic N 2 fixation had been long attributed to the tropical and subtropical latitudinal bands of the ocean, e.g. 13 , while other ecological niches such as high latitude waters, oxygen minimum zones and the vast dark realm of the ocean (below the euphotic zone) are now recognized as active N 2 fixation sites 14–16. It is likely that the inclusion of these previously unaccounted for active N 2 fixation sites will be more important in equilibrating denitrification and N 2 fixation rates than the underestimation of rates due to discrepancies between isotopic tracer methods. In chronically stratified open ocean regions such as the vast subtropical gyres, primary production depends largely on external fixed nitrogen inputs provided by N 2 fixation performed by prokaryotes termed 'diazotrophs'. Diazotrophic cyanobacteria are photosynthetic prokaryotes (with the exception of the photoheterotrophic Candidatus Atelocyanobacterium thalassa which cannot photosynthesize) 17 that thrive in oligotrophic tropical and subtropical waters of the oceans where they provide an important source of fixed nitrogen for other phyto-plankton 13. Despite being classically regarded as photoautotrophs, some unicellular diazotrophic cyanobacteria like Cyanothece are able to take up dissolved organic matter (DOM) molecules photoheterotrophically 18. As well, various filamentous diazotrophic cyanobacteria such as Anabaena bear genes for amino acids transport, which may be used to incorporate amino acids from the in situ DOM pool, or to assimilate amino acids self-produced during diazotrophic growth 19

When intentions turn into action : pathways to successful firm performance

Entrepreneurship brings wealth to nations and contributes to their economic growth. People can take many paths to become entrepreneurs. Some join the family business, whilst others are born entrepreneurs, letting their innate intuition lead them into firm creation. For many, though, being able to learn and acquire the right skills is critical for a successful career as an entrepreneur. Like other human capital factors, entrepreneurial skills can be acquired. In today's fast-changing society, it is of utmost importance for entrepreneurs not only to gain these skills but also to be surrounded by a supportive environment that will (1) guide them in the creation of their business idea and (2) help them succeed and keep their business alive. Taking the theory of planned behaviour (TPB) as an initial theoretical framework, this paper studies the pathways that lead newly established entrepreneurs to successful firm performance. In this paper, qualitative comparative analysis (QCA) is used to study a sample of 49 entrepreneurs who responded to an online survey. The results reveal different pathways leading to successful firm performance. This study fills a theoretical and empirical gap and makes a valuable contribution to the literature on entrepreneurial behaviour by exploring the combinations of factors that best explain entrepreneurs' success in achieving high firm performance. Examining the entrepreneurial process and the factors that guide entrepreneurs towards new firm success provides valuable insights that can hel

Intangible capital and business productivity in the hotel industry

Intangible capital is a key factor of productivity growth. This paper analyses how the internal intangible capital of the company and external intangible capital influence its productivity. This contribution focuses on the hotel industry since it is a key industry of the Spanish economy, such that any increase in its productivity has an impact on the entire economy. Both, the intangible capital of the company and that of the region in which the company is located are considered as determinants of productivity. Likewise, the importance of other agglomeration economies in the productivity of hotel companies is taken into account. A model estimates firm level determinants of productivity, controlling for regional characteristics that include intangible capital. The findings suggest that, as expected, investment of innovation by hotel companies and regions positively affects company productivity. In addition, there is evidence of the presence of agglomeration economies, both in specialization and urbanization economies. Also, the elasticity of the intangible capital itself is higher in smaller hotel companies

An optimisation approach for the e-grocery order picking and delivery problem

[EN] Traditional supermarket chains that are adopting an omni-channel approach must now carry out the order picking and delivery processes to serve online orders, previously done by the customer. The complexity of the logistics processes has increased, therefore modelling and optimising e-grocery operations becomes definitely important. Since there are few studies modelling order picking and delivery processes, we propose an approach that simultaneously optimises the decision variables of different functions which have traditionally been treated separately. In this study, we present a linear programming model for store-based e-fulfilment strategies with multiple picking locations. The proposed model optimises the allocation of online orders to stores, based on the e-fulfilment costs. As well as minimising the picking and delivery costs, the proposed approach consolidates workloads in order to avoid idle times and reduce the amount of resources required. A weighted sum method is applied to compute the solution, integrating parameters that represent different store features such as the product range, sales mode and physical store activities. The proposed model has been tested on one of the largest grocery sellers, showing that substantial savings can be achieved by reallocating orders to different stores, time windows and delivery vehicles. By focusing on optimising e-fulfilment resources, this approach serves as a guide for traditional grocery sellers to redesign their supply chains and to facilitate decision-making at a managerial level.Funding was provided by Universidade de Vigo.Vazquez-Noguerol, M.; Comesaña-Benavides, J.; Poler, R.; Prado-Prado, JC. (2022). An optimisation approach for the e-grocery order picking and delivery problem. Central European Journal of Operations Research. 30(3):961-990. https://doi.org/10.1007/s10100-020-00710-9S96199030

The refugee entrepreneurship process from/in emerging economies

The paper examines several refugee experiences in Mexico and presents their reasons for leaving their home countries. A gap in research is identifying the entrepreneurial process experienced by refugee entrepreneurs. We use the case study of 10 Latin American refugees in Mexico to propose a conceptual framework that describes the entrepreneurial process of refugee entrepreneurs. We have found that this process begins with the abandonment of the country of origin, followed by the traumatic experiences that caused flight and the difficulties they face in the pilgrimage to the host country. These events help shape the entrepreneurial intention of the refugees

Longitudinal variability of diazotroph abundances in the subtropical North Atlantic Ocean

Diazotrophy-related studies in the North Atlantic have largely focused on its western tropical area, leaving the subtropics and the east undersampled. We studied the longitudinal distribution of Trichodesmium, UCYN-A, UCYN-B, the putative Gammaproteobacterium g-24774A11 and Richelia (Het1) along 24.58N, using quantitative polymerase chain reaction on different size fractions (10, 10–3 and 3–0.2 mm) and additional filament counts for Trichodesmium. Trichodesmium was the most abundant phylotype, followed by UCYN-A, g-24774A11 and Het1, with maximum abundances of 8.8 ! 105, 2.0 ! 105, 3.3 ! 103 and 3.4 ! 102 nifH copies L21, respectively, whereas UCYN-B was mostly undetected. A clear shift in the diazotroph community was observed at !308W, coinciding with the transition between the North Atlantic Subtropical Gyre boundary and inner core. This transition zone divided the transect into an eastern half dominated by UCYN-A and western half dominated by Trichodesmium and g-24774A11. g-24774A11 was only detected in the 10–3 mm fraction, suggesting their association with larger microbes or aggregates. Our results indicate that typical size fractionation by 10 mm is not optimal for reconciling diazotroph phylotypes to N2 fixation rates and that non-cyanobacterial diazotrophs may contribute importantly to bulk diazotrophic activity in the western subtropical North Atlantic.Consolider-Malaspina (CSD2008-00077), CAIBEX (CTM2007-66408- CO2-02). HOTMIX (CTM2011-30010-CO2-01)Versión del editor1,749