7,991 research outputs found
Novel role for the LKB1 pathway in controlling monocarboxylate fuel transporters
A question preoccupying many researchers is how signal transduction pathways control metabolic processes and energy production. A study by Jang et al. (Jang, C., G. Lee, and J. Chung. 2008. J. Cell Biol. 183:11–17) provides evidence that in Drosophila melanogaster a signaling network controlled by the LKB1 tumor suppressor regulates trafficking of an Sln/dMCT1 monocarboxylate transporter to the plasma membrane. This enables cells to import additional energy sources such as lactate and butyrate, enhancing the repertoire of fuels they can use to power vital activities
Precursors of non-Markovianity
Using the paradigm of information backflow to characterize a non-Markovian
evolution, we introduce so-called precursors of non-Markovianity, i.e.
necessary properties that the system and environment state must exhibit at
earlier times in order for an ensuing dynamics to be non-Markovian. In
particular, we consider a quantitative framework to assess the role that
established system-environment correlations together with changes in
environmental states play in an emerging non-Markovian dynamics. By defining
the relevant contributions in terms of the Bures distance, which is
conveniently expressed by means of the quantum state fidelity, these quantities
are well defined and easily applicable to a wide range of physical settings. We
exemplify this by studying our precursors of non-Markovianity in discrete and
continuous variable non-Markovian collision models.Comment: 9 pages, 4 figures. Close to published versio
The COVID-19 pandemic and the challenge of using technology for medical education in low and middle income countries
Identification and biotechnological characterization of lactic acid bacteria isolated from chickpea sourdough in northwestern Argentina
Chickpea, a relevant legume worldwide, can be nutritional and functionally improved by fermentation with lactic acid bacteria (LAB). In order to select suitable autochthonous starter cultures, we isolated and identified LAB from kabuli chickpeas cultivated and consumed in northwestern Argentina, and screened their relevant
techno-functional properties. Chickpeas were milled and spontaneously fermented with daily back-slopping at 37 °C for 6 days and evolution of microbial populations were followed by plate counting. Phenotypic and genotypic methods including (GTG)5-based PCR fingerprinting and 16S rDNA sequencing were used to differentiate and identify the isolates to species level. A marked increase of LAB counts was observed throughout fermentation raising from 0.88 ± 0.35 log CFU/g of unfermented flours to 9.61 ± 0.21 log CFU/g after 5 backslopping steps with a concomitant pH decline from 6.09 ± 0.05 to 4.40 ± 0.03. Eighteen strains belonging to four LAB genera and six species: Enterococcus durans, E. mundtii, Lactococcus garvieae, Pediococcus pentosaceus, Weissella cibaria and W. paramesenteroides were identified in chickpea sourdoughs. Based on their abilities, Weissella cibaria CRL 2205 (acidification capacity), W. paramesenteroides CRL 2191 (proteolytic activity), Pediococcus pentosaceus CRL 2145 (gallate decarboxylase and peptidase activities), Lactococcus garviae CRL 2199 (α-galactosidase activity) and E. durans CRL 2193 (antimicrobial activity), were selected to design novel fermented chickpea products.Fil: Saez, Gabriel Dario. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad San Pablo Tucumán; ArgentinaFil: Saavedra, Maria Lucila. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Hebert, Elvira Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Zarate, Gabriela del Valle. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad San Pablo Tucumán; Argentin
Strain-dependent variations in stress coping behavior are mediated by a 5-HT/GABA interaction within the prefrontal corticolimbic system
Background: Serotonin and Îł- Aminobutyric acid (GABA) transmission is crucial in coping strategies. Methods: Here, using mice from 2 inbred strains widely exploited in behavioral neurochemistry, we investigated whether serotonin transmission in medial prefrontal cortex and GABA in basolateral amygdala determine strain-dependent liability to stress response and differences in coping. Results: C57BL/6J mice displayed greater immobility in the forced swimming test, higher serotonin outflow in medial prefrontal cortex, higher GABA outflow in basolateral amygdala induced by stress, and higher serotonin 1A receptor levels in medial prefrontal cortex accompanied by lower GABAb receptor levels in basolateral amygdala than DBA/2J mice. In assessing whether serotonin in medial prefrontal cortex determines GABA functioning in response to stress and passive coping behavior in C57BL/6J and DBA/2J mice, we observed that selective prefrontal serotonin depletion in C57BL/6J and DBA/2J reduced stress-induced GABA outflow in basolateral amygdala and immobility in the forced swimming test. Conclusions: These results show that strain-dependent prefrontal corticolimbic serotonin/GABA regulation determines the strain differences in stress-coping behavior in the forced swimming test and point to a role of a specific neuronal system in genetic susceptibility to stress that opens up new prospects for innovative therapies for stress disorders
Small subunit ribosomal metabarcoding reveals extraordinary trypanosomatid diversity in Brazilian bats
Background:
Bats are a highly successful, globally dispersed order of mammals that occupy a wide array of ecological niches. They are also intensely parasitized and implicated in multiple viral, bacterial and parasitic zoonoses. Trypanosomes are thought to be especially abundant and diverse in bats. In this study, we used 18S ribosomal RNA metabarcoding to probe bat trypanosome diversity in unprecedented detail.
Methodology/Principal Findings:
Total DNA was extracted from the blood of 90 bat individuals (17 species) captured along Atlantic Forest fragments of EspĂrito Santo state, southeast Brazil. 18S ribosomal RNA was amplified by standard and/or nested PCR, then deep sequenced to recover and identify Operational Taxonomic Units (OTUs) for phylogenetic analysis. Blood samples from 34 bat individuals (13 species) tested positive for infection by 18S rRNA amplification. Amplicon sequences clustered to 14 OTUs, of which five were identified as Trypanosoma cruzi I, T. cruzi III/V, Trypanosoma cruzi marinkellei, Trypanosoma rangeli, and Trypanosoma dionisii, and seven were identified as novel genotypes monophyletic to basal T. cruzi clade types of the New World. Another OTU was identified as a trypanosome like those found in reptiles. Surprisingly, the remaining OTU was identified as Bodo saltans–closest non-parasitic relative of the trypanosomatid order. While three blood samples featured just one OTU (T. dionisii), all others resolved as mixed infections of up to eight OTUs.
Conclusions/Significance:
This study demonstrates the utility of next-generation barcoding methods to screen parasite diversity in mammalian reservoir hosts. We exposed high rates of local bat parasitism by multiple trypanosome species, some known to cause fatal human disease, others non-pathogenic, novel or yet little understood. Our results highlight bats as a long-standing nexus among host-parasite interactions of multiple niches, sustained in part by opportunistic and incidental infections of consequence to evolutionary theory as much as to public health.
Author summary:
Bats make up a mega-diverse, intensely parasitized order of volant mammals whose unique behavioural and physiological adaptations promote infection by a vast array of microorganisms. Trypanosomes stand out as ancient protozoan parasites of bats. As cryptic morphology, low parasitaemia and selective growth in culture have recurrently biased survey, we used 18S ribosomal RNA metabarcoding to resolve bat trypanosomatid diversity in Atlantic Forest fragments of southeast Brazil. Next to several unknown species, our deep sequence-based detection and assignment protocol recognized multiple known human-pathogenic trypanosomes, another linked to reptile hosts as well as a non-parasitic kinetoplastid in the blood of various phyllostomid bats. The striking permissivity exposed here, in a region where bat trypanosomes recently featured in a fatal case of Chagas disease, compels further research on bats’ role in the dispersal and spill-over of various microorganisms among humans and wildlife
A Relational Approach for the Understanding of the Hegemonic Masculinities. Insights from Pierre Bourdieu, Georg Simmel and Marianne Weber
This paper addresses the issue of relationality between man and woman and how this
can undermine the forms of masculine hegemony in the society. Simmel’s relational
approach, rooted in an essentialist vision of gender construction, and Bourdieu’s
constructivist realism, seem not effective in questioning the gender relation in itself.
Indeed, both are more concerned to how hegemony works in crystallizing gendered
roles in the society and less on how this changes or can change. The binary scheme that
informs Simmel’s and Bourdieu’s efforts in understanding power in gender relations is,
2
in line with Marianne Weber’s statement, the main obstacle that hides relations
generative of social transformations. Nowadays the symbolic negotiations between the
pluralities of gender configurations require a focus on the relationality and we share this
analytical perspective. Indeed, it is from the point of view of the social construction of
gender that it seems to be possible to approach the hegemonic masculinity and how it
changes in different times and places
The conformational evolution of elongated polymer solutions tailors the polarization of light-emission from organic nanofibers
Polymer fibers are currently exploited in tremendously important
technologies. Their innovative properties are mainly determined by the behavior
of the polymer macromolecules under the elongation induced by external
mechanical or electrostatic forces, characterizing the fiber drawing process.
Although enhanced physical properties were observed in polymer fibers produced
under strong stretching conditions, studies of the process-induced nanoscale
organization of the polymer molecules are not available, and most of fiber
properties are still obtained on an empirical basis. Here we reveal the
orientational properties of semiflexible polymers in electrospun nanofibers,
which allow the polarization properties of active fibers to be finely
controlled. Modeling and simulations of the conformational evolution of the
polymer chains during electrostatic elongation of semidilute solutions
demonstrate that the molecules stretch almost fully within less than 1 mm from
jet start, increasing polymer axial orientation at the jet center. The
nanoscale mapping of the local dichroism of individual fibers by polarized
near-field optical microscopy unveils for the first time the presence of an
internal spatial variation of the molecular order, namely the presence of a
core with axially aligned molecules and a sheath with almost radially oriented
molecules. These results allow important and specific fiber properties to be
manipulated and tailored, as here demonstrated for the polarization of emitted
light.Comment: 45 pages, 10 figures, Macromolecules (2014
Relationship between corneal temperature and i0ntraocular pressure in healthy Individuals. a clinical thermographic analysis
To study the geographical distribution of corneal temperature (CT) and its influence on the intraocular pressure (IOP) of healthy human volunteers. Materials and Methods. Fifteen subjects (7 M, 8 F), 33.8 +/- 17.4 years old, were enrolled in this pilot, cross-sectional study. Measurements of CT were taken after one hour with closed eyelids (CET) or closed eyelids with a cooling mask (cm-CET) and compared to baseline. Results. If compared to baseline, after CET, average CT significantly increased by 0.56 degrees C in the RE and by 0.48 degrees C in the LE (p < 0.001) and IOP concomitantly significantly increased by 1.13 mm Hg and 1.46 mm Hg, respectively, in each eye (p < 0.001). After cm-CET, average CT significantly decreased by 0.11 degrees C and 0.20 degrees C, respectively, in the RE and LE (RE p = 0.04; LE p = 0.024), followed by a significant IOP decrease of 2.19 mm Hg and 1.54 mm Hg, respectively, in each eye (RE p < 0.001; LE = 0.0019). Conclusion. Significant variations of CT occurred after CET and cm-CET and were directly correlated with significant differences of IOP. It can be speculated that both oxidative stress and sympathetic nerve fiber stimulation by temperature oscillations may affect the regulation of AH vortex flow and turnover, thus influencing IOP values
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