727 research outputs found

    Traditional use of shore platforms:a study of the artisanal management of salinas on the Maltese Islands (Central Mediterranean)

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    Shore platforms and salinas in the Mediterranean region have a long-standing relationship, rooted in the traditional practice of salt making. On small islands with limited natural resources, the production of salt from seawater, through insolation and intense human endeavour, offered numerous economic benefits. Salt has been a foremost natural resource for millennia with a range of uses from preserving edible foods to cooking, cleaning, laundry, and hygiene, and for medicinal uses in dilute solutions. Within the Maltese Islands, this traditional activity was developed primarily on the soft limestone shore platforms situated along low-lying rocky coasts. Although coastal production has declined in number over the years, a few salinas have persisted in their artisanal practice and are becoming a cultural geo-heritage attraction. The aim of this article is to explore the multiple geographies of this industry on two shore platforms by examining the complicated relationships that have emerged and molded between the physical landscape and human culture. Mapping out these relations through the traditional but complex management systems at two salinas, that is, the salinas at Delimara Point (Malta) and those at Xwejni Bay (Gozo), highlights the delicate nature of these relations as well as the need to support them in order to continually reproduce the cultural micro-landscape. The resultant micro-landscape is becoming an increasingly important living expression of the cultural geo-heritage of the Maltese Islands, which requires careful understanding and management of these relations if it is to be maintained as a vibrant geo-tourist attraction.peer-reviewe

    Co-Located Collaborative Visual Analytics around a Tabletop Display

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    How managers can build trust in strategic alliances: a meta-analysis on the central trust-building mechanisms

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    Trust is an important driver of superior alliance performance. Alliance managers are influential in this regard because trust requires active involvement, commitment and the dedicated support of the key actors involved in the strategic alliance. Despite the importance of trust for explaining alliance performance, little effort has been made to systematically investigate the mechanisms that managers can use to purposefully create trust in strategic alliances. We use Parkhe’s (1998b) theoretical framework to derive nine hypotheses that distinguish between process-based, characteristic-based and institutional-based trust-building mechanisms. Our meta-analysis of 64 empirical studies shows that trust is strongly related to alliance performance. Process-based mechanisms are more important for building trust than characteristic- and institutional-based mechanisms. The effects of prior ties and asset specificity are not as strong as expected and the impact of safeguards on trust is not well understood. Overall, theoretical trust research has outpaced empirical research by far and promising opportunities for future empirical research exist

    Determination of the structure and geometry of N-heterocyclic carbenes on Au(111) using high-resolution spectroscopy

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    N-heterocyclic carbenes (NHCs) bind very strongly to transition metals due to their unique electronic structure featuring a divalent carbon atom with a lone pair in a highly directional sp(2)-hybridized orbital. As such, they can be assembled into monolayers on metal surfaces that have enhanced stability compared to their thiol-based counterparts. The utility of NHCs to form such robust self-assembled monolayers (SAMs) was only recently recognized and many fundamental questions remain. Here we investigate the structure and geometry of a series of NHCs on Au(111) using high-resolution X-ray photoelectron spectroscopy and density functional theory calculations. We find that the N-substituents on the NHC ring strongly affect the molecule-metal interaction and steer the orientation of molecules in the surface layer. In contrast to previous reports, our experimental and theoretical results provide unequivocal evidence that NHCs with N-methyl substituents bind to undercoordinated adatoms to form flat-lying complexes. In these SAMs, the donor-acceptor interaction between the NHC lone pair and the undercoordinated Au adatom is primarily responsible for the strong bonding of the molecules to the surface. NHCs with bulkier N-substituents prevent the formation of such complexes by forcing the molecules into an upright orientation. Our work provides unique insights into the bonding and geometry of NHC monolayers; more generally, it charts a clear path to manipulating the interaction between NHCs and metal surfaces using traditional coordination chemistry synthetic strategies

    Experience-dependent changes in hippocampal spatial activity and hippocampal circuit function are disrupted in a rat model of Fragile X Syndrome

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    BACKGROUND: Fragile X syndrome (FXS) is a common single gene cause of intellectual disability and autism spectrum disorder. Cognitive inflexibility is one of the hallmarks of FXS with affected individuals showing extreme difficulty adapting to novel or complex situations. To explore the neural correlates of this cognitive inflexibility, we used a rat model of FXS (Fmr1(−/y)). METHODS: We recorded from the CA1 in Fmr1(−/y) and WT littermates over six 10-min exploration sessions in a novel environment—three sessions per day (ITI 10 min). Our recordings yielded 288 and 246 putative pyramidal cells from 7 WT and 7 Fmr1(−/y) rats, respectively. RESULTS: On the first day of exploration of a novel environment, the firing rate and spatial tuning of CA1 pyramidal neurons was similar between wild-type (WT) and Fmr1(−/y) rats. However, while CA1 pyramidal neurons from WT rats showed experience-dependent changes in firing and spatial tuning between the first and second day of exposure to the environment, these changes were decreased or absent in CA1 neurons of Fmr1(−/y) rats. These findings were consistent with increased excitability of Fmr1(−/y) CA1 neurons in ex vivo hippocampal slices, which correlated with reduced synaptic inputs from the medial entorhinal cortex. Lastly, activity patterns of CA1 pyramidal neurons were dis-coordinated with respect to hippocampal oscillatory activity in Fmr1(−/y) rats. LIMITATIONS: It is still unclear how the observed circuit function abnormalities give rise to behavioural deficits in Fmr1(−/y) rats. Future experiments will focus on this connection as well as the contribution of other neuronal cell types in the hippocampal circuit pathophysiology associated with the loss of FMRP. It would also be interesting to see if hippocampal circuit deficits converge with those seen in other rodent models of intellectual disability. CONCLUSIONS: In conclusion, we found that hippocampal place cells from Fmr1(−/y) rats show similar spatial firing properties as those from WT rats but do not show the same experience-dependent increase in spatial specificity or the experience-dependent changes in network coordination. Our findings offer support to a network-level origin of cognitive deficits in FXS. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13229-022-00528-z

    Enriching strategic variety in new ventures through external knowledge

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    To build profitable market positions, new ventures have to address multiple challenges on several fronts. These ventures can compete by being simple (focused) or applying varied ways to compete. The likelihood of these ventures remaining competitive depends on their ability to build novelty into their products and operations, an activity that requires infusing knowledge into their operations. Most ventures, however, have limited knowledge bases and the reach (scope) of their external connections is limited, a factor that prompts them to tap into different external sources in their local areas. This article reports an empirical study of 140 new ventures located in seven regional clusters in Spain. The results show that new ventures can enrich the variety of their strategic repertoire by accessing diverse sources of external knowledge and being exposed to external novel knowledge, while absorptive capacity moderates this relationship. The degree of social development of these clusters also has a positive impact on the strategic variety of new ventures, exhibiting an inverted U-shape curve

    Knowledge Sharing in Alliances and Alliance Portfolios

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    We develop a model of knowledge sharing in alliances and alliance portfolios. We show that, once the issue of encouraging effective collaboration is put center stage, many standard intuitions of the learning race view and alliance portfolio literature are overturned or qualified. Partners engage in learning races in some cases, but exhibit “altruistic” behaviors in other cases. They may reduce their own absorptive capacity or increase the transparency of their own operations to facilitate their partner’s learning. In alliance portfolios, we show that not all substitutability between alliance portfolio partners is bad. We distinguish between substitutability in implementation and substitutability in rival benefits and show that the latter is conducive to knowledge sharing. Our work contributes toward putting the literature on learning alliances on a more solid foundation by emphasizing the importance of commitments that leading firms can make to encourage collaboration

    Considering Intra-individual Genetic Heterogeneity to Understand Biodiversity

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    In this chapter, I am concerned with the concept of Intra-individual Genetic Hetereogeneity (IGH) and its potential influence on biodiversity estimates. Definitions of biological individuality are often indirectly dependent on genetic sampling -and vice versa. Genetic sampling typically focuses on a particular locus or set of loci, found in the the mitochondrial, chloroplast or nuclear genome. If ecological function or evolutionary individuality can be defined on the level of multiple divergent genomes, as I shall argue is the case in IGH, our current genetic sampling strategies and analytic approaches may miss out on relevant biodiversity. Now that more and more examples of IGH are available, it is becoming possible to investigate the positive and negative effects of IGH on the functioning and evolution of multicellular individuals more systematically. I consider some examples and argue that studying diversity through the lens of IGH facilitates thinking not in terms of units, but in terms of interactions between biological entities. This, in turn, enables a fresh take on the ecological and evolutionary significance of biological diversity

    Semi-automatic enrichment of crowdsourced synonymy networks: the WISIGOTH system applied to Wiktionary

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    International audienceSemantic lexical resources are a mainstay of various Natural Language Processing applications. However, comprehensive and reliable resources are rare and not often freely available. Handcrafted resources are too costly for being a general solution while automatically-built resources need to be validated by experts or at least thoroughly evaluated. We propose in this paper a picture of the current situation with regard to lexical resources, their building and their evaluation. We give an in-depth description of Wiktionary, a freely available and collaboratively built multilingual dictionary. Wiktionary is presented here as a promising raw resource for NLP. We propose a semi-automatic approach based on random walks for enriching Wiktionary synonymy network that uses both endogenous and exogenous data. We take advantage of the wiki infrastructure to propose a validation "by crowds". Finally, we present an implementation called WISIGOTH, which supports our approach

    Transcriptomic Profiling of the Adaptive and Innate Immune Responses of Atlantic Salmon to Renibacterium salmoninarum Infection

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    IndexaciĂłn: Scopus.Bacterial Kidney Disease (BKD), which is caused by a Gram-positive, intracellular bacterial pathogen (Renibacterium salmoninarum), affects salmonids including Atlantic salmon (Salmo salar). However, the transcriptome response of Atlantic salmon to BKD remained unknown before the current study. We used a 44K salmonid microarray platform to characterise the global gene expression response of Atlantic salmon to BKD. Fish (~54 g) were injected with a dose of R. salmoninarum (H-2 strain, 2 × 108 CFU per fish) or sterile medium (control), and then head kidney samples were collected at 13 days post-infection/injection (dpi). Firstly, infection levels of individuals were determined through quantifying the R. salmoninarum level by RNA-based TaqMan qPCR assays. Thereafter, based on the qPCR results for infection level, fish (n = 5) that showed no (control), higher (H-BKD), or lower (L-BKD) infection level at 13 dpi were subjected to microarray analyses. We identified 6,766 and 7,729 differentially expressed probes in the H-BKD and L-BKD groups, respectively. There were 357 probes responsive to the infection level (H-BKD vs. L-BKD). Several adaptive and innate immune processes were dysregulated in R. salmoninarum-infected Atlantic salmon. Adaptive immune pathways associated with lymphocyte differentiation and activation (e.g., lymphocyte chemotaxis, T-cell activation, and immunoglobulin secretion), as well as antigen-presenting cell functions, were shown to be differentially regulated in response to BKD. The infection level-responsive transcripts were related to several mechanisms such as the JAK-STAT signalling pathway, B-cell differentiation and interleukin-1 responses. Sixty-five microarray-identified transcripts were subjected to qPCR validation, and they showed the same fold-change direction as microarray results. The qPCR-validated transcripts studied herein play putative roles in various immune processes including pathogen recognition (e.g., tlr5), antibacterial activity (e.g., hamp and camp), regulation of immune responses (e.g., tnfrsf11b and socs1), T-/B-cell differentiation (e.g., ccl4, irf1 and ccr5), T-cell functions (e.g., rnf144a, il13ra1b and tnfrsf6b), and antigen-presenting cell functions (e.g., fcgr1). The present study revealed diverse immune mechanisms dysregulated by R. salmoninarum in Atlantic salmon, and enhanced the current understanding of Atlantic salmon response to BKD. The identified biomarker genes can be used for future studies on improving the resistance of Atlantic salmon to BKD. © Copyright © 2020 Eslamloo, Caballero-Solares, Inkpen, Emam, Kumar, Bouniot, Avendaño-Herrera, Jakob and Rise.https://www.frontiersin.org/articles/10.3389/fimmu.2020.567838/ful
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