Fungal parasitism depends on the ability to invade host organisms and mandates adaptive cell wall remodeling to avoid detection and defense reactions by the host. All plant and human pathogens share ...invasive strategies, which aid to escape the chitin-triggered and chitin-targeted host immune system. Here we describe the full spectrum of the chitin/chitosan-modifying enzymes in the mycoparasite Trichoderma atroviride with a central role in cell wall remodeling. Rapid adaption to a variety of growth conditions, environmental stresses and host defense mechanisms such as oxidative stress depend on the concerted interplay of these enzymes and, ultimately, are necessary for the success of the mycoparasitic attack. To our knowledge, we provide the first in class description of chitin and associated glycopolymer synthesis in a mycoparasite and demonstrate that they are essential for biocontrol. Eight chitin synthases, six chitin deacetylases, additional chitinolytic enzymes, including six chitosanases, transglycosylases as well as accessory proteins are involved in this intricately regulated process. Systematic and biochemical classification, phenotypic characterization and mycoparasitic confrontation assays emphasize the importance of chitin and chitosan assembly in vegetative development and biocontrol in T. atroviride. Our findings critically contribute to understanding the molecular mechanism of chitin synthesis in filamentous fungi and mycoparasites with the overarching goal to selectively exploit the discovered biocontrol strategies.
Food additives such as titanium dioxide (E171), iron oxides and hydroxides (E172), silver (E174), and gold (E175) are highly used as colorants while silicon dioxide (E551) is generally used as ...anticaking in ultra-processed foodstuff highly used in the Western diets. These additives contain nanosized particles (1–100 nm) and there is a rising concern since these nanoparticles could exert major adverse effects due to they are not metabolized but are accumulated in several organs. Here, we analyze the evidence of gastrotoxicity, hepatotoxicity and the impact of microbiota on gut-brain and gut-liver axis induced by E171, E172, E174, E175 and E551 and their non-food grade nanosized counterparts after oral consumption. Although, no studies using these food additives have been performed to evaluate neurotoxicity or alterations in animal behavior, their non-food grade nanosized counterparts have been associated with stress, depression, cognitive and eating disorders as signs of animal behavior alterations. We identified that these food additives induce gastrotoxicity, hepatotoxicity and alterations in gut microbiota and most evidence points out oxidative stress as the main mechanism of toxicity, however, the role of oxidative stress as the main mechanism needs to be explored further.
The evidence of toxicity induced by oral consumption of E171, E172, E174, E175, E551 and their nanoparticles counterparts. Oral consumption of titanium dioxide (E171), iron oxide and hydroxides (E172), silver (E174), gold (E175) and silicon dioxide (E551) causes several signs of toxicity in the gastrointestinal tissues and liver (blue bullets) and oxidative stress in both (red bullets). However, the evidence of oxidative stress is restricted to description of increase in reactive oxygen species (ROS), decrease in antioxidant enzymes (catalase, superoxide dismutase and, glutathione reductase) and oxidative damage to biomolecules such as lipids, proteins and DNA. On the other hand, there is no available evidence of neurotoxicity of these five food-additives, however, their nanosized counterparts used in animal experimental models have induced clear signs of neurotoxicity and alterations in the behavior but scarce evidence of oxidative stress has been associated with. Display omitted
•E171, E172, E174, E175 and E551 food additives contain a fraction of nanoparticles.•E171, E172, E174, E175 and E551 are accumulated inducing gastro and hepatotoxicity.•Microbiome is altered by oral consumption of E171, E172, E174, E175 and E551.•Neurotoxicity and alterations in behavior and cognition are potentials effects.•Oxidative stress is important in their toxicity but further studies are needed.
Gelatinous organisms are crucial components of marine ecosystems and some species imply social and economic consequences. However, certain geographic areas, such as the temperate Southwestern ...Atlantic (SWA, 27° - 56° S), remain understudied in terms of jellyfish ecological data. We analyzed 3,727 plankton samples collected along ~6.7 million km2 over a 31-year period (1983-2014) to determine the occurrence, abundance, and diversity patterns of hydromedusae in the SWA. Analyses were made at both community and species levels. Two abundance hot spots of hydromedusae were identified, where values up to 2,480 ind. m-3 were recorded between 2003 and 2014. Liriope tetraphylla and Obelia spp. were the main responsible for recurrent peaks. Diversity indexes were in the range of those published for temperate areas worldwide, and some coastal zones showed values that can be considered moderate to high for a temperate neritic region. The community analysis yielded 10 groups following previously determined biogeographic schemes throughout the study area. This work enhances the knowledge of hydromedusae in the SWA and provides essential information about the current global warming context and the gelatinous zooplankton data necessity.
Periphyton communities grown in microcosms were studied under the exposure to different arsenate (As) and phosphate (P) regimes with the aim of revealing the effect of chronic exposure to As on ...periphyton physiological and structural characteristics. Also, we aimed to study periphyton changes on sensitivity to As, exposed to different P and As regimes. As affected structural and functional parameters of periphyton communities starved of P, inhibiting algal growth, photosynthetic capacity, changing community composition and reducing the ability of the community to retain P. The effects of As on these parameters were only detected in P starved communities, showing that chronic exposure to As led to changes in the photosynthetic apparatus under the conditions of P-limitation, but not when P-availability was higher. This fact reveals a lower toxicity and/or a higher adaptation of the P-amended community. Intracellular As contents were higher in communities starved of P. However, As tolerance was only induced by the combination of As and P but not by As or P alone indicating that tolerance induction may be an ATP-dependent mechanism. This study reveals that chronic exposure of natural communities to environmentally realistic As concentrations will damage periphyton communities affecting key ecosystem processes, as P uptake, leading to changes in stream ecosystems, as these organisms play a key role in nutrient cycling through nutrient uptake and transfer to higher trophic levels.
•As affected structural and functional parameters of periphyton starved of P.•Effects of As were detected in noP communities, but not when P was available.•Intracellular As contents were higher in communities starved of P.•As tolerance was induced by the combination of As and P but not by As or P alone.•Chronic exposure to realistic As levels can lead to changes in stream ecosystems.
Health-care-associated infections are the most prevalent adverse events of hospital care, posing a substantial threat to patient safety and burden on society. Hand hygiene with alcohol-based hand rub ...is the most effective preventive strategy to reduce health-care-associated infections. Over the past two decades, various interventions have been introduced and studied to improve hand hygiene compliance among health-care workers. The global implementation of the WHO multimodal hand hygiene improvement strategy and constant efforts to replace the use of soap and water with alcohol-based hand rub have led to a faster and more efficient hand cleaning method. These strategies have strongly contributed to the success of behaviour change and a subsequent decrease in health-care-associated infections and cross-transmission of multidrug-resistant organisms worldwide. The WHO multimodal behaviour change strategy requires a series of elements including system change as a prerequisite for behaviour change, education, monitoring and performance feedback, reminders in the workplace, and an institutional safety climate. Successful adoption of the promotion strategy requires adaptation to available resources and sociocultural contexts. This Review focuses on the major advances and challenges in hand hygiene research and practices in the past 20 years and sets out various ways forward for improving this lifesaving action.
In many schools of architecture worldwide, design studios are frequently isolated from everyday life and tend to focus on theory without experience. In countries with complex social problems, such as ...Colombia, experiential learning can offer valuable opportunities for architectural education to become an agency for social reconstruction and peace building. This works proposes a teaching method which centres on the promotion of significant learning, through live projects as a complement to studio-based projects. Bloom’s revised taxonomy and Fink’s taxonomy for levels of knowledge were used as references. In order to develop and test this method, 15 different live projects were designed, built and analysed over the course of four years. These involved the participation of 170 undergraduate learners, various national and international teachers, six sponsors from the construction industry and 12 children’s foundations. The findings reveal valuable insights into the development of intellectual, physical and emotional dimensions through these experiences.
Mycoparasitic Trichoderma species are applied as biocontrol agents in agriculture to guard plants against fungal diseases. During mycoparasitism, Trichoderma directly interacts with phytopathogenic ...fungi, preceded by a specific recognition of the host and resulting in its disarming and killing. In various fungal pathogens, including mycoparasites, signalling via heterotrimeric G proteins plays a major role in regulating pathogenicity-related functions. However, the corresponding receptors involved in the recognition of host-derived signals are largely unknown. Functional characterization of Trichoderma atroviride Gpr1 revealed a prominent role of this seven-transmembrane protein of the cAMP-receptor-like family of fungal G-protein-coupled receptors in the antagonistic interaction with the host fungus and governing of mycoparasitism-related processes. Silencing of gpr1 led to an avirulent phenotype accompanied by an inability to attach to host hyphae. Furthermore, gpr1-silenced transformants were unable to respond to the presence of living host fungi with the expression of chitinase- and protease-encoding genes. Addition of exogenous cAMP was able to restore host attachment in gpr1-silenced transformants but could not restore mycoparasitic overgrowth. A search for downstream targets of the signalling pathway(s) involving Gpr1 resulted in the isolation of genes encoding e.g. a member of the cyclin-like superfamily and a small secreted cysteine-rich protein. Although silencing of gpr1 caused defects similar to those of mutants lacking the Tga3 Gα protein, no direct interaction between Gpr1 and Tga3 was observed in a split-ubiquitin two-hybrid assay.
Most Cuban antislavery narratives from the 19th century were published abroad due to censorship. However, some antislavery children’s stories circulated without restriction in public and private ...schools across the island. These stories are little known and have not been studied as part of the abolitionist effort in Cuba. I examine the antislavery stories that appeared in Cirilo Villaverde’s El librito de los cuentos (1847) and Francisco Javier Balmaseda’s Fábulas morales (1858). These books were approved by Spanish censors and became official reading material in schools at a time when slavery was the foundation of Cuba’s economy. I argue that because the children’s genre was not perceived as politically dangerous and was, therefore, less scrutinized, Villaverde and Balmaseda used it as a safe platform to promote their anticolonial programs. I consider Villaverde’s and Balmaseda’s strategies vis-à-vis censorship and draw from postcolonial theory to discuss the use of violence in these stories.
Forcibly displaced adolescents face increased risks for mental illness and distress, with adolescent girls disproportionately affected in part due to heightened gender inequity. Although the family ...unit has the potential to promote healthy development in adolescents, few family interventions have employed a gender transformative approach or included male siblings to maximize benefits for adolescent girls.
This study will assess a whole-family and gender transformative intervention-Sibling Support for Adolescent Girls in Emergencies (SSAGE)-to prevent mental health disorders among adolescent girls in Colombia who were recently and forcibly displaced from Venezuela. The study will employ a hybrid type 1 effectiveness-implementation pilot randomized control trial (RCT) to test the program's effectiveness to explore determinants of implementation to establish the feasibility, acceptability, and fidelity of SSAGE. To address these aims, we will enroll 180 recently arrived, forcibly displaced adolescent girls in an RCT and examine the program's effectiveness in the prevention of mental illness (through reduction in anxiety, depression, interpersonal sensitivity, and somatization symptoms) one-month post-intervention. We will use contextually adapted to collect data on the hypothesized mechanistic pathways, including family attachment, gender-equitable family functioning, self-esteem, and coping strategies. The implementation evaluation will employ mixed methods to assess the program's feasibility, acceptability, fidelity, and barriers and facilitators to successful implementation.
Findings can support humanitarian program implementation, as well as inform policy to support adolescent girls' mental health and to prevent the myriad disorders that can arise as a result of exposure to displacement, conflict, and inequitable gender norms.
Polymorphism of natural fats is very important in the food industry since it is related to macroscopic properties of final products, including texture, color and appearance. The effect of addition of ...sucrose esters on crystallization kinetics and polymorphic behavior of cupuassu fat (CF) and its stearin fractions obtained by dry fractionation at 29°C (S‐29), 26 (S‐26), and 24 (S‐24) was studied by polarized light microscopy, differential scanning calorimetry, and small and wide angle X‐ray scattering. In situ experiments were performed in real‐time using synchrotron radiation as the light source. Sucrose esters S‐170 and P‐170 shortened induction times of crystallization, acting as a seed even at low supercooling. In addition to the kinetic effects, S‐170 modified polymorphic behavior. Depending on processing conditions used (under thermal cycles or isothermal storage), it promoted crystallization in a specific polymorphic form: β′2 (CF and its stearins) or β2 (S‐29). Crystallization in a stable and unique β′‐form makes CF and its stearins a good alternative to trans‐fats. With the addition of sucrose ester S‐170, S‐29's increased tendency to crystallize in β2‐form extends its applications in chocolate and coatings.
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