Debaryomyces hansenii is a halotolerant/halophilic yeast usually found in salty environments. The yeast accumulated sodium at high concentrations, which improved growth in salty media. In contrast, ...lithium was toxic even at low concentrations and its presence prevented cell proliferation. To analyse the responses to both cations, metabolite levels, enzymatic activities and gene expression were determined, showing that NaCl and LiCl trigger different cellular responses. At high concentrations of NaCl (0.5 or 1.5 M) cells accumulated higher amounts of the intermediate metabolites glyoxylate and malate and, at the same time, the levels of intracellular oxoglutarate decreased. Additionally, 0.5 M NaCl increased the activity of the enzymes isocitrate lyase and malate synthase involved in the synthesis of glyoxylate and malate respectively and decreased the activity of isocitrate dehydrogenase. Moreover, transcription of the genes coding for isocitrate lyase and malate synthase was activated by NaCl. Also, cells accumulated phosphate upon NaCl exposure. None of these effects was provoked when LiCl (0.1 or 0.3 M) was used instead of NaCl. Lithium induced accumulation of higher amounts of oxoglutarate and decreased the concentrations of glyoxylate and malate to non‐detectable levels. Cells incubated with lithium also showed higher activity of the isocitrate dehydrogenase and neither increased isocitrate lyase and malate synthase activities nor the transcription of the corresponding genes. In summary, we show that sodium, but not lithium, up regulates the shunt of the glyoxylic acid in D. hansenii and we propose that this is an important metabolic adaptation to thrive in salty environments.
Sodium, but not lithium, activates the glyoxylic acid shunt in Debaryomyces hansenii.
Take‐away
Sodium is a beneficial element for D. hansenii. By contrast, lithium is toxic.
Sodium, but not lithium, up regulates the glyoxylic acid shunt in D. hansenii.
Activation of glyoxylic acid cycle may be an important adaptation to salt stress.
Topic Modeling in Embedding Spaces Dieng, Adji B.; Ruiz, Francisco J. R.; Blei, David M.
Transactions of the Association for Computational Linguistics,
01/2020, Letnik:
8
Journal Article
Recenzirano
Odprti dostop
Topic modeling analyzes documents to learn meaningful patterns of words. However, existing topic models fail to learn interpretable topics when working with large and heavy-tailed vocabularies. To ...this end, we develop the
(
), a generative model of documents that marries traditional topic models with word embeddings. More specifically, the
models each word with a categorical distribution whose natural parameter is the inner product between the word’s embedding and an embedding of its assigned topic. To fit the
, we develop an efficient amortized variational inference algorithm. The
discovers interpretable topics even with large vocabularies that include rare words and stop words. It outperforms existing document models, such as latent Dirichlet allocation, in terms of both topic quality and predictive performance.
Probiotics and synbiotics are used to treat chronic diseases, principally due to their role in immune system modulation and the anti-inflammatory response. The present study reviewed the effects of ...probiotics and synbiotics on intestinal chronic diseases in in vitro, animal, and human studies, particularly in randomized clinical trials. The selected probiotics exhibit in vitro anti-inflammatory properties. Probiotic strains and cell-free supernatants reduced the expression of pro-inflammatory cytokines via action that is principally mediated by toll-like receptors. Probiotic administration improved the clinical symptoms, histological alterations, and mucus production in most of the evaluated animal studies, but some results suggest that caution should be taken when administering these agents in the relapse stages of IBD. In addition, no effects on chronic enteropathies were reported. Probiotic supplementation appears to be potentially well tolerated, effective, and safe in patients with IBD, in both CD and UC. Indeed, probiotics such as
536 improved the clinical symptoms in patients with mild to moderate active UC. Although it has been proposed that probiotics can provide benefits in certain conditions, the risks and benefits should be carefully assessed before initiating any therapy in patients with IBD. For this reason, further studies are required to understand the precise mechanism by which probiotics and synbiotics affect these diseases.
Plants interact with root microbes via chemical signaling, which modulates competence or symbiosis. Although several volatile organic compounds (VOCs) from fungi may affect plant growth and ...development, the signal transduction pathways mediating VOC sensing are not fully understood. 6‐pentyl‐2H‐pyran‐2‐one (6‐PP) is a major VOC biosynthesized by Trichoderma spp. which is probably involved in plant–fungus cross‐kingdom signaling. Using microscopy and confocal imaging, the effects of 6‐PP on root morphogenesis were found to be correlated with DR5:GFP, DR5:VENUS, H2B::GFP, PIN1::PIN1::GFP, PIN2::PIN2::GFP, PIN3::PIN3::GFP and PIN7::PIN7::GFP gene expression. A genetic screen for primary root growth resistance to 6‐PP in wild‐type seedlings and auxin‐ and ethylene‐related mutants allowed identification of genes controlling root architectural responses to this metabolite. Trichoderma atroviride produced 6‐PP, which promoted plant growth and regulated root architecture, inhibiting primary root growth and inducing lateral root formation. 6‐PP modulated expression of PIN auxin‐transport proteins in a specific and dose‐dependent manner in primary roots. TIR1, AFB2 and AFB3 auxin receptors and ARF7 and ARF19 transcription factors influenced the lateral root response to 6‐PP, whereas EIN2 modulated 6‐PP sensing in primary roots. These results indicate that root responses to 6‐PP involve components of auxin transport and signaling and the ethylene‐response modulator EIN2.
The use of probiotics and synbiotics in the prevention and treatment of different disorders has dramatically increased over the last decade. Both probiotics and synbiotics are well known ingredients ...of functional foods and nutraceuticals and may provide beneficial health effects because they can influence the intestinal microbial ecology and immunity. The present study reviews the effects of probiotics and synbiotics on obesity, insulin resistance syndrome (IRS), type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD) in human randomized clinical trials. Select probiotics and synbiotics provided beneficial effects in patients with obesity, mainly affecting the body mass index and fat mass. Some probiotics had beneficial effects on IRS, decreasing the cell adhesion molecule-1 levels, and the synbiotics decreased the insulin resistance and plasma lipid levels. Moreover, select probiotics improved the carbohydrate metabolism, fasting blood glucose, insulin sensitivity and antioxidant status and also reduced metabolic stress in subjects with T2D. Some probiotics and synbiotics improved the liver and metabolic parameters in patients with NAFLD. The oral intake of probiotics and synbiotics as co-adjuvants for the prevention and treatment of obesity, IRS, T2D and NAFLD is partially supported by the data shown in the present review. However, further studies are required to understand the precise mechanism of how probiotics and synbiotics affect these metabolic disorders.
Competition is a widespread interaction among carnivores, ultimately manifested through one or more dimensions of the species' ecological niche. One of the most explicit manifestations of competitive ...interactions regards spatial displacement. Its interpretation under a theoretical context provides an important tool to deepen our understanding of biological systems and communities, but also for wildlife management and conservation. We used Bayesian multispecies occupancy models on camera-trapping data from multiple sites in Southwestern Europe (SWE) to investigate competitive interactions within a carnivore guild, and to evaluate how species' ecological traits are shaping coexistence patterns. Seventeen out of 26 pairwise interactions departed from a hypothesis of independent occurrence, with spatial association being twice as frequent as avoidance. Association behaviors were only detected among mesocarnivores, while avoidance mainly involved mesocarnivores avoiding the apex predator (n = 4) and mesocarnivore-only interactions (n = 2). Body mass ratios, defined as the dominant over the subordinate species body mass, revealed an important negative effect (β̂ = −0.38; CI95 = −0.81 to −0.06) on co-occurrence probability, and support that spatially explicit competitive interactions are mostly expressed by larger species able to dominate over smaller ones, with a threshold in body mass ratios of ∼4, above which local-scale intraguild coexistence is unlikely. We found a weak relationship between pairwise trophic niche overlap and the probability of coexistence (β̂ = −0.19; CI95 = −0.58 to 0.21), suggesting that competition for feeding resources may not be a key driver of competition, at least at the scale of our analysis. Despite local-scale avoidance, regional-scale coexistence appears to be maintained by the spatial structuring of the competitive environment. We provide evidence that SWE ecosystems consist of spatially structured competitive environments, and propose that coexistence among near-sized species is likely achieved through the interplay of “facultative” and “behavioral” character displacements. Factors influencing carnivore coexistence likely include context-dependent density and trait-mediated effects, which should be carefully considered for a sound understanding of the mechanisms regulating these communities.
Lack of trust is thought to be one of the most significant barriers to the consumption of organic foods, which is an important dimension of sustainable behaviour. Building trust in organic foods is ...the central objective of this paper. Based on information processing models focusing on what message to transmit and how, and on the premise that to improve trust, two different dimensions (functionality and authenticity) must be managed simultaneously, this paper analyzes the comparative effectiveness of different combinations of message arguments, forms of appeal and sources on consumer trust. To this end, an experiment was designed with a total of 800 participants, in which 36 different treatments were tested. The results show strong interactions between the three variables considered and suggest that the most effective combinations for building trust are: the health argument put across by an expert, the authenticity argument transmitted by a producers’ union, the elitist argument made by an expert and lastly, the social argument transmitted by a public authority, using an emotional form of appeal in all four cases. These results serve to complete the previous literature on the subject, in which communication activities are recommended but the questions of what to say, how to say it and who should say it are not specifically addressed.
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•Two useful dimensions for studying and managing trust: functionality and authenticity.•Clear influences on trust building of message source, argument and form of appeal.•Best messages are interactions with health, authenticity, social or elitism arguments.•Best message combination is emotional appeal with congruent argument and source.
The COVID-19 pandemic triggered vast governmental lockdowns. The impact of these lockdowns on mental health is inadequately understood. On the one hand such drastic changes in daily routines could be ...detrimental to mental health. On the other hand, it might not be experienced negatively, especially because the entire population was affected.
The aim of this study was to determine mental health outcomes during pandemic induced lockdowns and to examine known predictors of mental health outcomes. We therefore surveyed n = 9,565 people from 78 countries and 18 languages. Outcomes assessed were stress, depression, affect, and wellbeing. Predictors included country, sociodemographic factors, lockdown characteristics, social factors, and psychological factors.
Results indicated that on average about 10% of the sample was languishing from low levels of mental health and about 50% had only moderate mental health. Importantly, three consistent predictors of mental health emerged: social support, education level, and psychologically flexible (vs. rigid) responding. Poorer outcomes were most strongly predicted by a worsening of finances and not having access to basic supplies.
These results suggest that on whole, respondents were moderately mentally healthy at the time of a population-wide lockdown. The highest level of mental health difficulties were found in approximately 10% of the population. Findings suggest that public health initiatives should target people without social support and those whose finances worsen as a result of the lockdown. Interventions that promote psychological flexibility may mitigate the impact of the pandemic.
Candida albicans Potassium Transporters Ruiz-Castilla, Francisco J; Ruiz Pérez, Francisco S; Ramos-Moreno, Laura ...
International journal of molecular sciences,
04/2022, Letnik:
23, Številka:
9
Journal Article
Recenzirano
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Potassium is basic for life. All living organisms require high amounts of intracellular potassium, which fulfils multiple functions. To reach efficient potassium homeostasis, eukaryotic cells have ...developed a complex and tightly regulated system of transporters present both in the plasma membrane and in the membranes of internal organelles that allow correct intracellular potassium content and distribution. We review the information available on the pathogenic yeast
While some of the plasma membrane potassium transporters are relatively well known and experimental data about their nature, function or regulation have been published, in the case of most of the transporters present in intracellular membranes, their existence and even function have just been deduced because of their homology with those present in other yeasts, such as
Finally, we analyse the possible links between pathogenicity and potassium homeostasis. We comment on the possibility of using some of these transporters as tentative targets in the search for new antifungal drugs.
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