Functional trait diversity can provide insight into ecosystem function beyond that provided by species diversity measures. The relationship between functional diversity and natural stressors has ...received less attention compared to anthropogenic stressors. In this study, we investigated how two natural stressors, water salinity and flow intermittence, affect functional richness and functional redundancy of aquatic invertebrate communities using seven biological traits and 39 modalities. For this purpose, we characterized these functional diversity measures in 22 Mediterranean streams with a gradient of natural salinity and flow intermittence. Our findings showed that both functional richness and functional redundancy decreased with increased stress by water salinity and flow intermittence for all the studied traits but more rapidly for the former, suggesting that water salinity is a stronger environmental stressor than flow intermittence. Our study also described an antagonistic interaction of the two study stressors, in which the net effect of both is less than the sum of their independent effects. This study emphasizes that in saline streams, characterized by lower functional richness and functional redundancy, the loss of any taxon can have a huge impact on community functioning. In particular, the functional singularity of saline intermittent streams makes them extremely sensitive to additional anthropogenic impacts. In the context of future global change scenarios, which predict higher flow intermittence and water salinity, this study gives a better understanding of the functional features of these types of ecosystems.
Ion channel conformational changes within the lipid membrane are a key requirement to control ion passage. Thus, it seems reasonable to assume that lipid composition should modulate ion channel ...function. There is increasing evidence that this implicates not just an indirect consequence of the lipid influence on the physical properties of the membrane, but also specific binding of selected lipids to certain protein domains. The result is that channel function and its consequences on excitability, contractility, intracellular signaling or any other process mediated by such channel proteins, could be subjected to modulation by membrane lipids. From this it follows that development, age, diet or diseases that alter lipid composition should also have an influence on those cellular properties. The wealth of data on the non-annular lipid binding sites in potassium channel from Streptomyces lividans (KcsA) makes this protein a good model to study the modulation of ion channel structure and function by lipids. The fact that this protein is able to assemble into clusters through the same non-annular sites, resulting in large changes in channel activity, makes these sites even more interesting as a potential target to develop lead compounds able to disrupt such interactions and hopefully, to modulate ion channel function. This Article is Part of a Special Issue Entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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•Specific lipids bound to ion channels modulate their structure and function.•Non-annular lipid binding sites on KcsA mediate interactions leading to protein clustering.•Lipid–protein and protein–protein interactions strongly modulate KcsA function.
Sirtuin 1 (Sirt1) and Sirtuin 2 (Sirt2) belong to the family of NAD+ (nicotinamide adenine dinucleotide-positive)-dependent class III histone deacetylases and are involved in regulating lifespan. As ...cancer is a disease of ageing, targeting Sirtuins is emerging as a promising antitumour strategy. Here we present Salermide (N-{3-(2-hydroxy-naphthalen-1-ylmethylene)-amino-phenyl}-2-phenyl-propionamide), a reverse amide with a strong in vitro inhibitory effect on Sirt1 and Sirt2. Salermide was well tolerated by mice at concentrations up to 100 muM and prompted tumour-specific cell death in a wide range of human cancer cell lines. The antitumour activity of Salermide was primarily because of a massive induction of apoptosis. This was independent of global tubulin and K16H4 acetylation, which ruled out a putative Sirt2-mediated apoptotic pathway and suggested an in vivo mechanism of action through Sirt1. Consistently with this, RNA interference-mediated knockdown of Sirt1, but not Sirt2, induced apoptosis in cancer cells. Although p53 has been reported to be a target of Sirt1, genetic p53 knockdowns showed that the Sirt1-dependent proapoptotic effect of Salermide is p53-independent. We were finally able to ascribe the apoptotic effect of Salermide to the reactivation of proapoptotic genes epigenetically repressed exclusively in cancer cells by Sirt1. Taken together, our results underline Salermide's promise as an anticancer drug and provide evidence for the molecular mechanism through which Sirt1 is involved in human tumorigenesis.
Recent studies suggest that immune-modulating single-nucleotide polymorphisms (SNPs) influence the risk of developing cancer-related infections. Here, we evaluated whether 36 SNPs within 14 ...immune-related genes are associated with the risk of invasive aspergillosis (IA) and whether genotyping of these variants might improve disease risk prediction. We conducted a case-control association study of 781 immunocompromised patients, 149 of whom were diagnosed with IA. Association analysis showed that the IL4Rrs2107356 and IL8rs2227307 SNPs (using dbSNP numbering) were associated with an increased risk of IA (IL4Rrs2107356 odds ratio OR, 1.92; 95% confidence interval CI, 1.20 to 3.09; IL8rs2227307 OR, 1.73; 95% CI, 1.06 to 2.81), whereas the IL12Brs3212227 and IFNγrs2069705 variants were significantly associated with a decreased risk of developing the infection (IL12Brs3212227 OR, 0.60; 95% CI, 0.38 to 0.96; IFNγrs2069705 OR, 0.63; 95% CI, 0.41 to 0.97). An allogeneic hematopoietic stem cell transplantation (allo-HSCT)-stratified analysis revealed that the effect observed for the IL4Rrs2107356 and IFNγrs2069705 SNPs was stronger in allo-HSCT (IL4Rrs2107356 OR, 5.63; 95% CI, 1.20 to 3.09; IFNγrs2069705 OR, 0.24; 95% CI, 0.10 to 0.59) than in non-HSCT patients, suggesting that the presence of these SNPs renders patients more vulnerable to infection, especially under severe and prolonged immunosuppressive conditions. Importantly, in vitro studies revealed that carriers of the IFNγrs2069705C allele showed a significantly increased macrophage-mediated neutralization of fungal conidia (P = 0.0003) and, under stimulation conditions, produced higher levels of gamma interferon (IFNγ) mRNA (P = 0.049) and IFNγ and tumor necrosis factor alpha (TNF-α) cytokines (P value for 96 h of treatment with lipopolysaccharide PLPS-96 h, 0.057; P value for 96 h of treatment with phytohemagglutinin PPHA-96 h, 0.036; PLPS+PHA-96 h = 0.030; PPHA-72 h = 0.045; PLPS+PHA-72 h = 0.018; PLPS-96 h = 0.058; PLPS+PHA-96 h = 0.0058). Finally, we also observed that the addition of SNPs significantly associated with IA to a model including clinical variables led to a substantial improvement in the discriminatory ability to predict disease (area under the concentration-time curve AUC of 0.659 versus AUC of 0.564; P-2 log likehood ratio test = 5.2 · 10(-4) and P50.000 permutation test = 9.34 · 10(-5)). These findings suggest that the IFNγrs2069705 SNP influences the risk of IA and that predictive models built with IFNγ, IL8, IL12p70, and VEGFA variants can used to predict disease risk and to implement risk-adapted prophylaxis or diagnostic strategies.
We investigated central fatigue in 50 patients with chronic fatigue syndrome (CFS) and 50 matched healthy controls (HC). Resting state EEG was collected from 19 scalp locations during a 3 min, ...eyes-closed condition. Current densities were localized using exact low-resolution electromagnetic tomography (eLORETA). The Multidimensional Fatigue Inventory (MFI-20) and the Fatigue Severity Scale (FSS) were administered to all participants. Independent t-tests and linear regression analyses were used to evaluate group differences in current densities, followed by statistical non-parametric mapping (SnPM) correction procedures. Significant differences were found in the delta (1–3 Hz) and beta-2 (19–21 Hz) frequency bands. Delta sources were found predominately in the frontal lobe, while beta-2 sources were found in the medial and superior parietal lobe. Left-lateralized, frontal delta sources were associated with a clinical reduction in motivation. The implications of abnormal cortical sources in patients with CFS are discussed.
The application of nano-biotechnology to crop-science/agriculture (‘nanoagriculture’) is a recent development. While carbon nanotubes (CNTs) have been shown to dramatically improve germination of ...some comestible plants, deficiencies in consistency of behavior and reproducibility arise, partially from the variability of the CNTs used. In this work, factory-synthesized multi-walled-CNTs (MWCNTs) of quality-controlled specifications were seen to enhance the germinative growth of maize seedlings at low concentrations but depress it at higher concentrations. Growth enhancement principally arose through improved water delivery by the MWCNT. Polarized EDXRF spectrometry showed that MWCNTs affect mineral nutrient supply to the seedling through the action of the mutually opposing forces of inflow with water and retention in the medium by the ion-CNT transient-dipole interaction. The effect varied with ion type and MWCNT concentration. The differences of the Fe tissue concentrations when relatively high equimolar Fe
2+
or Fe
3+
was introduced, implied that the ion-CNT interaction might induce redox changes to the ion. The tissue Ca
2+
concentration manifested as the antipode of the Fe
2+
concentration indicating a possible cationic exchange in the cell wall matrix. SEM images showed that MWCNTs perforated the black-layer seed-coat that could explain the enhanced water delivery. The absence of perforations with the introduction of FeCl
2
/FeCl
3
reinforces the idea of the modification of MWCNT functionality by the ion-CNT interaction. Overall, in normal media, low dose MWCNTs were seen to be beneficial, improving water absorption, plant biomass and the concentrations of the essential Ca, Fe nutrients, opening a potential for possible future commercial agricultural applications.
•AR and VR have been successfully used to improve the student's performance.•A challenge for AR and VR lies in the digital literacy of teachers and students.•AR and VR require user's prior ...preparation to be exploited at its fullest.•The use of AR and VR in education might globally increase over the coming years.
Virtual and Augmented Reality (VR and AR, respectively) are technologies with potential impact in education, and can facilitate subjects, such as mathematics, that may be difficult for students. This manuscript presents a comprehensive review of works using VR and/or AR for teaching mathematics at all academic levels during the timespan from 2015 to June 2020. The work contributes by providing an overview of the findings, challenges, and trends for the use of these technologies. Results from the review indicate that both VR and AR have seen acceptance by students but using the technologies might be complicated if lectures are not designed adequately. Moreover, the number of publications involving AR and VR in teaching and learning maths has increased over time, and the demographics indicate that the technology is taking prevalence in developing countries.
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The growing demand for clean and efficient fuels in the world reflects the rapid growth in automotive vehicles and more stringent environmental regulations. Hence, the refining industry must employ ...diverse strategies to obtain a gasoline pool made up of streams from different processes focused on improving the fuel quality and the octane ratings suitable for the current demanding automotive performance. The composition of gasoline varies mainly from each country's policies, climate, environmental regulations, financial capacity, and local producer's oil refining infrastructure. However, a generally accepted composition by source of the gasoline pool is: FCC naphtha and reformate, making up about 60%, light straight-run naphtha and alkylate gasoline, around 30%, isomerate, close to 5%, and variable proportions of butane, oxygenating agents, such as methyl-ter-butyl ether (MTBE), ter-amyl-methyl ether (TAME) and/or ethanol and additives for the remaining 5%. This review is focused on the recent research in the advancement and development of catalysts for the different processes used by the oil refining industry to improve the composition and properties of gasoline fuels. A detailed section on the Fischer-Tropsch process, where liquid hydrocarbons are potentially employed to further produce clean gasoline, is also discussed. A section devoted to research on biogasoline as a potential renewable fuel is also addressed. Finally, a discussion of the physicochemical properties of the gasoline blending components is also provided.
We present here CAFE, the Calar Alto Fiber-fed Échelle spectrograph, a new instrument built at the Centro Astronomico Hispano Alemán (CAHA). CAFE is a single-fiber, high-resolution (R ~ 70 000) ...spectrograph, covering the wavelength range between 3650−9800 Å. It was built on the basis of the common design for Échelle spectrographs. Its main aim is to measure radial velocities of stellar objects up to V ~ 13−14 mag with a precision as good as a few tens of m s-1. To achieve this goal the design was simplified at maximum, removing all possible movable components, the central wavelength is fixed, as is the wavelength coverage; there is no filter wheel, etc. Particular care was taken with the thermal and mechanical stability. The instrument is fully operational and publically accessible at the 2.2 m telescope of the Calar Alto Observatory. In this article we describe (i) the design, summarizing its manufacturing phase; (ii) characterize the main properties of the instrument; (iii) describe the reduction pipeline; and (iv) show the results from the first light and commissioning runs. The preliminar results indicate that the instrument fulfills the specifications and can achieve the planned goals. In particular, the results show that the instrument is more efficient than anticipated, reaching a signal-to-noise of ~20 for a stellar object as faint as V ~ 14.5 mag in ~2700 s integration time. The instrument is a wonderful machine for exoplanetary research (by studying large samples of possible systems cotaining massive planets), galactic dynamics (highly precise radial velocities in moving groups or stellar associations), or astrochemistry.
A comparison of lignocellulose degradation, energy requirements, biogas production and microbial community analysis was done between a fungal (Pleurotus ostreatus, 28 d, 35 °C), thermal (1 h, 121 °C) ...and acid (2% HCl, 2 h, 123 °C) pre-treatment of bean straw. The results revealed that the type of pre-treatment had a great impact on lignocellulose degradation and energy demand, where the acid pre-treatment had higher solubilization capacity (lignin 67%, hemicellulose 68% and 0.49 g sugars·g−1 bean straw) and demanded less energy as compared with the fungal pre-treatment. Contrary, the type of pre-treatment did not have an apparent effect on the anaerobic digestion of the hydrolysates after 37 days of bioreactors operation in terms of biogas yield (142–165 mL g−1 chemical oxygen demand-COD), COD and sugars degradation (>80%). The bioreactor using acid pre-treatment hydrolysates showed differences in the total bacterial and archaea estimates, with a more pronounced increase in archaea (Euryarchaeota) and bacteria (Bacteroidetes, Firmicutes, and Proteobacteria), suggesting a more favorable composition for microbial growth. Overall, the acid pre-treatment was the most effective on all the parameters compared in this study. Further studies should include other important parameters to consider when selecting a pre-treatment method including environmental and economic implications of solid phase disposal and pH adjustment.
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•Effect of a fungal, acid and thermal pre-treatment of bean straw were compared.•Anaerobic digestion of hydrolysates from pre-treatments were also compared.•Acid pre-treatment yielded higher sugar solubilization with less energy demand.•Type of pre-treatment led to similar biogas yield but not microbial community.•Increase of archaea/bacteria occurred in the bioreactor from the acid pre-treatment.
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