The contents of consciousness are complex and dynamic and are embedded in perception and cognitio... more The contents of consciousness are complex and dynamic and are embedded in perception and cognition. The study of consciousness and subjective experience has been central to philosophy for centuries. However, despite its relevance for understanding cognition and behaviour, the empirical study of consciousness is relatively new, embroiled by the seemingly opposing subjective and objective sources of data. Francisco Varela (1946–2001) pioneered the empirical study of consciousness by developing novel, naturalised and rich approaches in a non-reductive and comprehensive manner. In this article, we review the main conceptual distinctions and philosophical challenges of consciousness research and highlight the main contributions of Varela and his associates: the development of neurophenomenology as a methodological framework that builds a bridge between subjective and objective sources of data and the discovery of gamma-band phase synchronisation as a neural marker of perceptual awareness...
Vector-borne diseases with reservoir cycles are complex to understand because new infections come... more Vector-borne diseases with reservoir cycles are complex to understand because new infections come from contacts of the vector with humans and different reservoirs. In this scenario, the basic reproductive number $\mathcal{R}^h_0$ of the system where the reservoirs are not included could turn out to be less than one, yet, an endemic equilibrium be observed. Indeed, when the reservoirs are taken back into account, the basic reproductive number $\mathcal{R}_0^r$, of only vectors and reservoirs, explains the endemic state. Furthermore, reservoirs cycles with a small basic reproductive number could contribute to reach an endemic state in the human cycle. Therefore, when controlling for the spread of a disease, it could not be enough to focus on specific reservoir cycles or only on the vector. In this work, we created a simple epidemiological model with a network of reservoirs where $\mathcal{R}_0^r$ is a bifurcation parameter of the system, explaining disease endemicity in the absence of...
Honey bees (Apis mellifera) are responsible for pollinating nearly 80% of all food-producing plan... more Honey bees (Apis mellifera) are responsible for pollinating nearly 80% of all food-producing plants, therefore, the success or failure of a colony is vital to global food production. However, not all insects are beneficial to humankind and sometimes it is necessary to reduce the population of disease-carrying mosquitoes by using insecticides. These chemical products not only affect mosquitoes but other insects such as Honey bees, causing imbalances across most ecosystems around the world. Our goal is to describe the influence of brood deaths on Honey Bee population dynamics and the potential impact of insecticides on these natural changes. We constructed a compartmental model using ordinary differential equations to describe brood birth, mortality, maturation and how the newly emerged adults live and die. To obtain our parameters we used data from 1975-76 to estimate the parameters in order to see how well our model fits the data. Finally, we implemented seasonality in our simulatio...
BackgroundAging is accompanied by alterations in immune response which leads to increased suscept... more BackgroundAging is accompanied by alterations in immune response which leads to increased susceptibility to infectious diseases, cancer, autoimmunity, and inflammatory disorders. This decline in immune function is termed as immunosenescence; however, the mechanisms are not fully elucidated. Experimental approaches of adaptive immunity, particularly for T cells, have been the main focus of immunosenescence research. This systematic review evaluates and discusses T cell markers implicated in immunosenescence.ObjectiveTo determine the best flow cytometry markers of circulating T cells associated with immunosenescence.MethodsWe systematically queried PubMed, MEDLINE, EBSCO, and BVS databases for original articles focused on two age groups of healthy humans: 18–44 (young adults) and >60 (older adults) years. In accordance with the Cochrane methodology, we synthesized data through qualitative descriptions and quantitative random effects meta-analysis due to extensive heterogeneity.Resu...
Background: The bacterial genus Exiguobacterium includes several species that inhabit environment... more Background: The bacterial genus Exiguobacterium includes several species that inhabit environments with a wide range of temperature, salinity, and pH. This is why the microorganisms from this genus are known generically as polyextremophiles. Several environmental isolates have been explored and characterized for enzyme production as well as for bioremediation purposes. In this line, toxic metal(loid) reduction by these microorganisms represents an approach to decontaminate soluble metal ions via their transformation into less toxic, insoluble derivatives. Microbial-mediated metal(loid) reduction frequently results in the synthesis of nanoscale structures—nanostructures (NS) —. Thus, microorganisms could be used as an ecofriendly way to get NS.Results: We analyzed the tolerance of Exiguobacterium acetylicum MF03, E. aurantiacum MF06, and E. profundum MF08 to silver(I), gold(III), and tellurium(IV) compounds. Specifically, we explored the ability of cell-free extracts from these bacte...
In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrog... more In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied. The silver nanoparticles were synthesized into each prepared hydrogel matrix achieving three significant, different-sized nanoparticles that were spherical in shape with a narrow size distribution. It is likely that the polymer network stabilized the nanoparticles. It was determined that the hydrogel network structure can control the size and shape of the nanoparticles. The hydrogel/silver nanohybrids were characterized by swelling degree, Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Antibacterial activity against Staphylococcus...
Magnetic nanoparticles have been extensively explored for the development of platforms for drug d... more Magnetic nanoparticles have been extensively explored for the development of platforms for drug delivery and imaging probes. In this work, we have used a modular capping strategy to produce magnetic gold-coated FeO (FeO@Au) nanoparticles, which have been decorated with a copper (II) complex containing a thioether derivative of clip-phen (FeO@Au@Cu), where the complex [Cu(2CP-Bz-SMe)] has affinity to bind DNA and proven nuclease activity (2CP-Bz-SMe=1,3-bis((1,10-phenanthrolin-2-yl)oxy)-N-(4-(methylthio)benzylidene)propan-2-imine). The functionalization of FeO@Au with the copper complex occurs through the sulfur atom of the thioether moiety, as indicated by Raman scattering on surface. The magnetic measurements showed the nanomaterial FeO@Au@Cu is still magnetic although the gold shell and the functionalization with the copper complex have diminished the magnetization due to the dilution of the magnetic core. The nuclease assays performed with FeO@Au@Cu indicate that the nuclease act...
Cutaneous leishmaniasis (CL) is a neglected tropical disease, which causes severe skin lesions. D... more Cutaneous leishmaniasis (CL) is a neglected tropical disease, which causes severe skin lesions. Due to the lack of effective vaccines, and toxicity or reduced effectiveness of available drugs in addition to complex and prolonged treatments, there is an urgent need to develop alternatives for the treatment for CL with different mechanisms of action. In our effort to search for new promising hits against parasites we prepared 18 acyl hydrazone derivatives of thiochroman-4-ones. Compounds were evaluated for their in vitro antileishmanial activity against the intracellular amastigote form of and cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Our results show that derivatization of the thiochroman-4-ones with acyl hydrazones significantly enhances the antileishmanial activity. Among the compounds tested semicarbazone and thiosemicarbazone derivatives of thioflavanone and displayed the highest antileishmanial activities, with EC values of 5.4 and 5.1 µM and low cytoto...
The S-containing heterocyclic compounds benzothiopyrans or thiochromones stand out as having prom... more The S-containing heterocyclic compounds benzothiopyrans or thiochromones stand out as having promising biological activities due to their structural relationship with chromones (benzopyrans), which are widely known as privileged scaffolds in medicinal chemistry. In this work, we report the synthesis of 35 thiochromone derivatives and the in vitro antileishmanial and cytotoxic activities. Compounds were tested against intracellular amastigotes ofand cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Compounds bearing a vinyl sulfone moiety,,,,,and, displayed the highest antileishmanial activity, with ECvalues lower than 10 μM and an index of selectivity over 100 for compoundsand. When the double bond or the sulfone moiety was removed, the activity decreased. Our results show that thiochromones bearing a vinyl sulfone moiety are endowed with high antileishmanial activity and low cytotoxicity.
This article attempts to clarify Francisco Varela's proposal of a neurophenomenology of time ... more This article attempts to clarify Francisco Varela's proposal of a neurophenomenology of time consciousness in the light of distinctions based on the philosophical literature of phenomenology and recent advances of neurobiology. The analysis is carried out considering three aspects. In the first of them, we discuss the phenomenological aspect of consciousness, accessible in first-person, which describes time as a structure with three inseparable moments (past-present-future) and three levels of temporality, and not merely as the chronometric time or clock time. In the second one, we analyze the neurobiological aspect of consciousness that tends to "explain" the phenomenological time in terms of three possible levels of neuronal integration. Thus, we propose a correspondence between the levels of phenomenological time and neural integration processes. Finally, we try to analyze this "correspondence" and the issues that follow from this by considering that the n...
The contents of consciousness are complex and dynamic and are embedded in perception and cognitio... more The contents of consciousness are complex and dynamic and are embedded in perception and cognition. The study of consciousness and subjective experience has been central to philosophy for centuries. However, despite its relevance for understanding cognition and behaviour, the empirical study of consciousness is relatively new, embroiled by the seemingly opposing subjective and objective sources of data. Francisco Varela (1946–2001) pioneered the empirical study of consciousness by developing novel, naturalised and rich approaches in a non-reductive and comprehensive manner. In this article, we review the main conceptual distinctions and philosophical challenges of consciousness research and highlight the main contributions of Varela and his associates: the development of neurophenomenology as a methodological framework that builds a bridge between subjective and objective sources of data and the discovery of gamma-band phase synchronisation as a neural marker of perceptual awareness...
Vector-borne diseases with reservoir cycles are complex to understand because new infections come... more Vector-borne diseases with reservoir cycles are complex to understand because new infections come from contacts of the vector with humans and different reservoirs. In this scenario, the basic reproductive number $\mathcal{R}^h_0$ of the system where the reservoirs are not included could turn out to be less than one, yet, an endemic equilibrium be observed. Indeed, when the reservoirs are taken back into account, the basic reproductive number $\mathcal{R}_0^r$, of only vectors and reservoirs, explains the endemic state. Furthermore, reservoirs cycles with a small basic reproductive number could contribute to reach an endemic state in the human cycle. Therefore, when controlling for the spread of a disease, it could not be enough to focus on specific reservoir cycles or only on the vector. In this work, we created a simple epidemiological model with a network of reservoirs where $\mathcal{R}_0^r$ is a bifurcation parameter of the system, explaining disease endemicity in the absence of...
Honey bees (Apis mellifera) are responsible for pollinating nearly 80% of all food-producing plan... more Honey bees (Apis mellifera) are responsible for pollinating nearly 80% of all food-producing plants, therefore, the success or failure of a colony is vital to global food production. However, not all insects are beneficial to humankind and sometimes it is necessary to reduce the population of disease-carrying mosquitoes by using insecticides. These chemical products not only affect mosquitoes but other insects such as Honey bees, causing imbalances across most ecosystems around the world. Our goal is to describe the influence of brood deaths on Honey Bee population dynamics and the potential impact of insecticides on these natural changes. We constructed a compartmental model using ordinary differential equations to describe brood birth, mortality, maturation and how the newly emerged adults live and die. To obtain our parameters we used data from 1975-76 to estimate the parameters in order to see how well our model fits the data. Finally, we implemented seasonality in our simulatio...
BackgroundAging is accompanied by alterations in immune response which leads to increased suscept... more BackgroundAging is accompanied by alterations in immune response which leads to increased susceptibility to infectious diseases, cancer, autoimmunity, and inflammatory disorders. This decline in immune function is termed as immunosenescence; however, the mechanisms are not fully elucidated. Experimental approaches of adaptive immunity, particularly for T cells, have been the main focus of immunosenescence research. This systematic review evaluates and discusses T cell markers implicated in immunosenescence.ObjectiveTo determine the best flow cytometry markers of circulating T cells associated with immunosenescence.MethodsWe systematically queried PubMed, MEDLINE, EBSCO, and BVS databases for original articles focused on two age groups of healthy humans: 18–44 (young adults) and >60 (older adults) years. In accordance with the Cochrane methodology, we synthesized data through qualitative descriptions and quantitative random effects meta-analysis due to extensive heterogeneity.Resu...
Background: The bacterial genus Exiguobacterium includes several species that inhabit environment... more Background: The bacterial genus Exiguobacterium includes several species that inhabit environments with a wide range of temperature, salinity, and pH. This is why the microorganisms from this genus are known generically as polyextremophiles. Several environmental isolates have been explored and characterized for enzyme production as well as for bioremediation purposes. In this line, toxic metal(loid) reduction by these microorganisms represents an approach to decontaminate soluble metal ions via their transformation into less toxic, insoluble derivatives. Microbial-mediated metal(loid) reduction frequently results in the synthesis of nanoscale structures—nanostructures (NS) —. Thus, microorganisms could be used as an ecofriendly way to get NS.Results: We analyzed the tolerance of Exiguobacterium acetylicum MF03, E. aurantiacum MF06, and E. profundum MF08 to silver(I), gold(III), and tellurium(IV) compounds. Specifically, we explored the ability of cell-free extracts from these bacte...
In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrog... more In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied. The silver nanoparticles were synthesized into each prepared hydrogel matrix achieving three significant, different-sized nanoparticles that were spherical in shape with a narrow size distribution. It is likely that the polymer network stabilized the nanoparticles. It was determined that the hydrogel network structure can control the size and shape of the nanoparticles. The hydrogel/silver nanohybrids were characterized by swelling degree, Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Antibacterial activity against Staphylococcus...
Magnetic nanoparticles have been extensively explored for the development of platforms for drug d... more Magnetic nanoparticles have been extensively explored for the development of platforms for drug delivery and imaging probes. In this work, we have used a modular capping strategy to produce magnetic gold-coated FeO (FeO@Au) nanoparticles, which have been decorated with a copper (II) complex containing a thioether derivative of clip-phen (FeO@Au@Cu), where the complex [Cu(2CP-Bz-SMe)] has affinity to bind DNA and proven nuclease activity (2CP-Bz-SMe=1,3-bis((1,10-phenanthrolin-2-yl)oxy)-N-(4-(methylthio)benzylidene)propan-2-imine). The functionalization of FeO@Au with the copper complex occurs through the sulfur atom of the thioether moiety, as indicated by Raman scattering on surface. The magnetic measurements showed the nanomaterial FeO@Au@Cu is still magnetic although the gold shell and the functionalization with the copper complex have diminished the magnetization due to the dilution of the magnetic core. The nuclease assays performed with FeO@Au@Cu indicate that the nuclease act...
Cutaneous leishmaniasis (CL) is a neglected tropical disease, which causes severe skin lesions. D... more Cutaneous leishmaniasis (CL) is a neglected tropical disease, which causes severe skin lesions. Due to the lack of effective vaccines, and toxicity or reduced effectiveness of available drugs in addition to complex and prolonged treatments, there is an urgent need to develop alternatives for the treatment for CL with different mechanisms of action. In our effort to search for new promising hits against parasites we prepared 18 acyl hydrazone derivatives of thiochroman-4-ones. Compounds were evaluated for their in vitro antileishmanial activity against the intracellular amastigote form of and cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Our results show that derivatization of the thiochroman-4-ones with acyl hydrazones significantly enhances the antileishmanial activity. Among the compounds tested semicarbazone and thiosemicarbazone derivatives of thioflavanone and displayed the highest antileishmanial activities, with EC values of 5.4 and 5.1 µM and low cytoto...
The S-containing heterocyclic compounds benzothiopyrans or thiochromones stand out as having prom... more The S-containing heterocyclic compounds benzothiopyrans or thiochromones stand out as having promising biological activities due to their structural relationship with chromones (benzopyrans), which are widely known as privileged scaffolds in medicinal chemistry. In this work, we report the synthesis of 35 thiochromone derivatives and the in vitro antileishmanial and cytotoxic activities. Compounds were tested against intracellular amastigotes ofand cytotoxic activity against human monocytes (U-937 ATCC CRL-1593.2). Compounds bearing a vinyl sulfone moiety,,,,,and, displayed the highest antileishmanial activity, with ECvalues lower than 10 μM and an index of selectivity over 100 for compoundsand. When the double bond or the sulfone moiety was removed, the activity decreased. Our results show that thiochromones bearing a vinyl sulfone moiety are endowed with high antileishmanial activity and low cytotoxicity.
This article attempts to clarify Francisco Varela's proposal of a neurophenomenology of time ... more This article attempts to clarify Francisco Varela's proposal of a neurophenomenology of time consciousness in the light of distinctions based on the philosophical literature of phenomenology and recent advances of neurobiology. The analysis is carried out considering three aspects. In the first of them, we discuss the phenomenological aspect of consciousness, accessible in first-person, which describes time as a structure with three inseparable moments (past-present-future) and three levels of temporality, and not merely as the chronometric time or clock time. In the second one, we analyze the neurobiological aspect of consciousness that tends to "explain" the phenomenological time in terms of three possible levels of neuronal integration. Thus, we propose a correspondence between the levels of phenomenological time and neural integration processes. Finally, we try to analyze this "correspondence" and the issues that follow from this by considering that the n...
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