Evolutionary Genetics of Microbial Symbiosis

Symbiosis is the living together of dissimilar organisms [1,2]. As such, symbiotic relationships can range from antagonist (parasitic) to mutualistic and can vary along this continuum within and between species in space and time. Microbial symbioses encompass a wide array of players (e.g., bacteria, fungi, and small eukaryotes) and are an integral part of organismal life, contributing to phenotypes at all levels of biological organization, from molecules to ecosystems. There has been an explosion of microbiological research on symbiosis emerging from the omics revolution, which has made many previously intractable symbioses available for dissection. Current research ranges from unraveling the biochemical interactions among symbiont partners to uncovering the incredible ecological diversity and dynamics of microbial communities and host associations. Host-microbes engage in extensive and complex cross-kingdom molecular dialogue, where symbionts can modulate their reciprocal gene expression patterns, complement metabolic pathways, and combine genetic information through DNA exchange, in some cases becoming sufficiently integrated through coinheritance to be considered as an evolutionary unit of selection. This extensive genetic and biochemical interplay has enormous implications in the emergence of novel traits and the overall diversification of life

Up the nose of the beholder? Aesthetic perception in olfaction as a decision-making process

Is the sense of smell a source of aesthetic perception? Traditional philosophical aesthetics has centered on vision and audition but eliminated smell for its subjective and inherently affective character. This article dismantles the myth that olfaction is an unsophisticated sense. It makes a case for olfactory aesthetics by integrating recent insights in neuroscience with traditional expertise about flavor and fragrance assessment in perfumery and wine tasting. My analysis concerns the importance of observational refinement in aesthetic experience. I argue that the active engagement with stimulus features in perceptual processing shapes the phenomenological content, so much so that the perceptual structure of trained smelling varies significantly from naive smelling. In a second step, I interpret the processes that determine such perceptual refinement in the context of neural decision-making processes, and I end with a positive outlook on how research in neuroscience can be used to benefit philosophical aesthetics

Pregnane X receptor and constitutive androstane receptor modulate differently CYP3A-mediated metabolism in earlyand late-stage cholestasis

AIM: To ascertain whether cholestasis affects the expression of two CYP3A isoforms (CYP3A1 and CYP3A2) and of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). METHODS: Cholestasis was induced by bile duct ligation in 16 male Wistar rats; whereas 8 sham-operated rats were used as controls. Severity of cholestasis was assessed on histological examination of liver sections, and serum concentrations of albumin, AST, ALT, GGT, ALPK and bilirubin. Gene and protein expressions of PXR, CAR, CYP3A1 and CYP3A2 were assessed by means of qRT-PCR and Western blot, respectively. Alterations in CYP3A activity were measured by calculating the kinetic parameters of 4-OH and 1'-OH-midazolam hydroxylation, marker reactions for CYP3A enzymes. RESULTS: The mRNA and protein expression of CYP3A1 increased significantly in mild cholestasis (P < 0.01). At variance, mRNA and protein expression of CYP3A2 didn't change in mild cholestasis, whereas the expression and activity of both CYP3A1 and CYP3A2 decreased dramatically when cholestasis became severe. Consistently with these observations, the nuclear expression of both PXR and CAR, which was measured because they both translocate into the cell nucleus after their activation, virtually disappeared in the late stage of cholestatic injury, after an initial increase. These results indicate that early- and late-stage cholestasis affects CYP3A-mediated drug metabolism differently, probably as consequence of the different activation of PXR and CAR. CONCLUSION: Early- and late-stage cholestasis affects CYP3A-mediated drug metabolism differently. PXR and CAR might be targeted therapeutically to promote CYP3A-mediated liver detoxification

Efecto del methoprene sobre <i>Musca domestica</i>: ensayos de laboratorio

To determine methoprene's (MTP) effect on fly Musca domestica emergence were performed laboratory bioassays using a technical formulation identified as MK55, in the form of a granulated insoluble in water. Concentrations of 1.625, 4.5 and 10 ppm of MTP were mixed directly with poultry manure, and larvae I of Musca domestica were fed (test 1). The same MTP concentrations (1.625, 4.5 and 10 ppm) were added to chicken feed and then, the manure produced by the chicken was used as feed to M. domestica larvae I ( test 2); each test involved five assays and one untreated check, in both larvae II and III were grown by feeding manure. Pupae were controlled until fly adults emergence. The percentage of fly growth in each assay decreased in relation to the increase of MTP concentrations and 77.1% of efficacy was shown when 10 ppm was used directly mixed with manure. And 83.7% of efficacy was demonstrated when used as a feed additive. However, a high variability of results was observed in low concentrations. MTP should be used at the highest doses and integrated with other methods to control M. domestica fly in poultry farms.Con el propósito de evaluar el efecto del methoprene (MTP) sobre la emergencia de adultos de Musca domestica, se realizaron ensayos bajo condiciones de laboratorio con una formulación granulada insoluble en agua, identificada como MK55. Concentraciones de 1.625, 4.5 y 10 ppm de MTP fueron mezcladas directamente con estiércol de gallina y ofrecidas como alimento a larvas I de M. domestica (test 1). Las mismas concentraciones de MTP (1.625, 4.5 y 10 ppm) fueron adicionadas al alimento balanceado para gallinas y luego la materia fecal producida por esos animales se usó como fuente alimenticia de larvas I de M. domestica (test 2); cada test involucró cinco ensayos y un control sin tratar, en ambos, larvas II y III se desarrollaron alimentándose con estiércol de gallina. Las pupas fueron controladas hasta la emergencia de los adultos. El porcentaje de moscas nacidas en cada ensayo disminuyó en relación al aumento de la concentración de MTP y se demostró una eficacia del 77,1% y del 83,7% cuando se utilizó 10 ppm mezclado directamente en las heces, y como aditivo en el alimento, respectivamente. No obstante, en bajas concentraciones se observó gran variabilidad en los resultados. El methoprene debería ser usado en concentraciones elevadas y en combinación con otros métodos para un control óptimo de adultos de M. domestica en explotaciones avícolas

An Online Tree-Based Approach for Mining Non-Stationary High-Speed Data Streams

 This paper presents a new learning algorithm for inducing decision trees from data streams. In these domains, large amounts of data are constantly arriving over time, possibly at high speed. The proposed algorithm uses a top-down induction method for building trees, splitting leaf nodes recursively, until none of them can be expanded. The new algorithm combines two split methods in the tree induction. The first method is able to guarantee, with statistical significance, that each split chosen would be the same as that chosen using infinite examples. By doing so, it aims at ensuring that the tree induced online is close to the optimal model. However, this split method often needs too many examples to make a decision about the best split, which delays the accuracy improvement of the online predictive learning model. Therefore, the second method is used to split nodes more quickly, speeding up the tree growth. The second split method is based on the observation that larger trees are able to store more information about the training examples and to represent more complex concepts. The first split method is also used to correct splits previously suggested by the second one, when it has sufficient evidence. Finally, an additional procedure rebuilds the tree model according to the suggestions made with an adequate level of statistical significance. The proposed algorithm is empirically compared with several well-known induction algorithms for learning decision trees from data streams. In the tests it is possible to observe that the proposed algorithm is more competitive in terms of accuracy and model size using various synthetic and real world datasets.  

Accelerated microevolution in an outer membrane protein (OMP) of the intracellular bacteria Wolbachia

<p>Abstract</p> <p>Background</p> <p>Outer membrane proteins (OMPs) of Gram-negative bacteria are key players in the biology of bacterial-host interactions. However, while considerable attention has been given to OMPs of vertebrate pathogens, relatively little is known about the role of these proteins in bacteria that primarily infect invertebrates. One such OMP is found in the intracellular bacteria <it>Wolbachia</it>, which are widespread symbionts of arthropods and filarial nematodes. Recent experimental studies have shown that the <it>Wolbachia </it>surface protein (WSP) can trigger host immune responses and control cell death programming in humans, suggesting a key role of WSP for establishment and persistence of the symbiosis in arthropods.</p> <p>Results</p> <p>Here we performed an analysis of 515 unique alleles found in 831 <it>Wolbachia </it>isolates, to investigate WSP structure, microevolution and population genetics. WSP shows an eight-strand transmembrane β-barrel structure with four extracellular loops containing hypervariable regions (HVRs). A clustering approach based upon patterns of HVR haplotype diversity was used to group similar WSP sequences and to estimate the relative contribution of mutation and recombination during early stages of protein divergence. Results indicate that although point mutations generate most of the new protein haplotypes, recombination is a predominant force triggering diversity since the very first steps of protein evolution, causing at least 50% of the total amino acid variation observed in recently diverged proteins. Analysis of synonymous variants indicates that individual WSP protein types are subject to a very rapid turnover and that HVRs can accommodate a virtually unlimited repertoire of peptides. Overall distribution of WSP across hosts supports a non-random association of WSP with the host genus, although extensive horizontal transfer has occurred also in recent times.</p> <p>Conclusions</p> <p>In OMPs of vertebrate pathogens, large recombination impact, positive selection, reduced structural and compositional constraints, and extensive lateral gene transfer are considered hallmarks of evolution in response to the adaptive immune system. However, <it>Wolbachia </it>do not infect vertebrates. Here we predict that the rapid turnover of WSP loop motifs could aid in evading or inhibiting the invertebrate innate immune response. Overall, these features identify WSP as a strong candidate for future studies of host-<it>Wolbachia </it>interactions that affect establishment and persistence of this widespread endosymbiosis.</p

Funding, Turnover, Sustainability and Digital Technologies: A Multicriteria Research Model for SMEs Facing a Challenging Context

none7sìAbstract: The pandemic crisis has meant a challenge for SMEs and a factor that can change the way of doing business. The current paper analyses the correlations between financial resources, turnover, sustainability, and digital technologies and how these components can be adapted to changes in the economy triggered by the pandemic crisis in the structure of activities carried out by SMEs. Resting on the importance of integrating the innovative, digital component to the activities of SMEs, in close connection with the financial resources component, a multicriteria research model for business has been developed, assessing the correlations between key variables and their influence on European SMEs. In order to fully define the concepts envisaged and to emphasise these correlations, multiple linear regression, clustering techniques, and correlation analysis were used. In the end, the proposed solution provided a common language through which companies can evaluate traditional processes and bring together the research components into business activities.Received: 26 February 2022 Accepted: 24 March 2022 Published: 27 March 2022openDel Baldo, M.; Sitnikov, C.; Vasilescu, L.; Mandache, L.; Ogarc˘a, R.; B˘andoi, A.; Ganea, E.Del Baldo, M.; Sitnikov, C.; Vasilescu, L.; Mandache, L.; Ogarc˘a, R.; B˘andoi, A.; Ganea, E

Underage drinking on saturday nights, sociodemographic and environmental risk factors: a cross-sectional study

BACKGROUND: Excessive alcohol consumption in underage people is a rising phenomenon. A major proportion of the disease burden and deaths of young people in developed nations is attributable to alcohol abuse. The aim of this study was to investigate social, demographic and environmental factors that may raise the risk of Saturday night drinking and binge drinking among Italian school students. METHODS: The study was conducted on a sample of 845 Italian underage school students, by means of an anonymous, self-test questionnaire. Multivariate logistic regression was applied to identify independent risk factors for alcohol drinking and binge drinking. Ordered logistic regression was used to identify independent risk factors for harmful drinking patterns. RESULTS: The independent variables that confer a higher risk of drinking in underage students are older age classes, male sex, returning home after midnight, belonging to a group with little respect for the rules, or to a group where young people are not seen as leaders. The higher the perception of alcohol consumption by the group, the higher the risk. Spending time in bars or discos coincides with a two-fold or four-fold increase, respectively, in the risk of alcohol consumption. CONCLUSION: Our findings show that certain environmental and social risk factors are associated with underage drinking. The most important role for preventing young people's exposure to these factors lies with the family, because only parents can exert the necessary control and provide a barrier against potentially harmful situations