13 research outputs found

    A System Approach on Organizational Innovations in the Agro-Food Sector: The Case of AFSCs in Flanders

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    Together with the evolution from the agro-industrial model to the sustainable rural development model (Roep and Wiskerke 2004), a part of the agro-food market has evolved from an anonymous, mass food market to a quality-food market. This shift is driven by factors, such as the changing relations between supply chain actors due to concentration in retail and processing, the growing importance of quality standards, considerable changes in consumer habits and preferences, the increasing attention for the multifunctional dimensions of agriculture and the establishment of new markets for public goods and services (Kirwan, Slee et al. 2003; Jahn, Zerger et al. 2007). As a consequence, the contemporary agro-food markets are more and more characterised by coordination between the actors in food supply chains. Collective action is not only adopted to improve supply chain logistics, but can also be used as a strategic instrument to realise market differentiation, to increase market share, or to obtain niche protection (Hobbs, Fearne et al. 2002; Vuylsteke, Collet et al. 2003; MĂ©nard and Klein 2004). Moreover, new forms of dynamism and innovative forms of cooperation, such as alternative food supply chains, are emerging (Marsden, Banks et al. 2000)...

    Physiological and transcriptomic evidence for a close coupling between chloroplast ontogeny and cell cycle progression in the pennate diatom Seminavis robusta

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    Despite the growing interest in diatom genomics, detailed time series of gene expression in relation to key cellular processes are still lacking. Here, we investigated the relationships between the cell cycle and chloroplast development in the pennate diatom Seminavis robusta. This diatom possesses two chloroplasts with a well-orchestrated developmental cycle, common to many pennate diatoms. By assessing the effects of induced cell cycle arrest with microscopy and flow cytometry, we found that division and reorganization of the chloroplasts are initiated only after S-phase progression. Next, we quantified the expression of the S. robusta FtsZ homolog to address the division status of chloroplasts during synchronized growth and monitored microscopically their dynamics in relation to nuclear division and silicon deposition. We show that chloroplasts divide and relocate during the S/G2 phase, after which a girdle band is deposited to accommodate cell growth. Synchronized cultures of two genotypes were subsequently used for a cDNA-amplified fragment length polymorphism-based genome-wide transcript profiling, in which 917 reproducibly modulated transcripts were identified. We observed that genes involved in pigment biosynthesis and coding for light-harvesting proteins were up-regulated during G2/M phase and cell separation. Light and cell cycle progression were both found to affect fucoxanthin-chlorophyll a/c-binding protein expression and accumulation of fucoxanthin cell content. Because chloroplasts elongate at the stage of cytokinesis, cell cycle-modulated photosynthetic gene expression and synthesis of pigments in concert with cell division might balance chloroplast growth, which confirms that chloroplast biogenesis in S. robusta is tightly regulated

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    A System Approach on Organizational Innovations in the Agro-Food Sector: The Case of AFSCs in Flanders

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    Together with the evolution from the agro-industrial model to the sustainable rural development model (Roep and Wiskerke 2004), a part of the agro-food market has evolved from an anonymous, mass food market to a quality-food market. This shift is driven by factors, such as the changing relations between supply chain actors due to concentration in retail and processing, the growing importance of quality standards, considerable changes in consumer habits and preferences, the increasing attention for the multifunctional dimensions of agriculture and the establishment of new markets for public goods and services (Kirwan, Slee et al. 2003; Jahn, Zerger et al. 2007). As a consequence, the contemporary agro-food markets are more and more characterised by coordination between the actors in food supply chains. Collective action is not only adopted to improve supply chain logistics, but can also be used as a strategic instrument to realise market differentiation, to increase market share, or to obtain niche protection (Hobbs, Fearne et al. 2002; Vuylsteke, Collet et al. 2003; MĂ©nard and Klein 2004). Moreover, new forms of dynamism and innovative forms of cooperation, such as alternative food supply chains, are emerging (Marsden, Banks et al. 2000)

    A sex-inducing pheromone triggers cell cycle arrest and mate attraction in the diatom Seminavis robusta

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    Although sexual reproduction is believed to play a major role in the high diversification rates and species richness of diatoms, a mechanistic understanding of diatom life cycle control is virtually lacking. Diatom sexual signalling is controlled by a complex, yet largely unknown, pheromone system. Here, a sex-inducing pheromone (SIP(+)) of the benthic pennate diatom Seminavis robusta was identified by comparative metabolomics, subsequently purified, and physicochemically characterized. Transcriptome analysis revealed that SIP(+) triggers the switch from mitosis-to-meiosis in the opposing mating type, coupled with the transcriptional induction of proline biosynthesis genes, and the release of the proline-derived attraction pheromone. The induction of cell cycle arrest by a pheromone, chemically distinct from the one used to attract the opposite mating type, highlights the existence of a sophisticated mechanism to increase chances of mate finding, while keeping the metabolic losses associated with the release of an attraction pheromone to a minimum
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