Optimization of Microalgal Harvesting with Inorganic and Organic Flocculants Using Factorial Design of Experiments

Microalgae have a lot of potential as a source of several compounds of interest to various industries. However, developing a sustainable and efficient harvesting process on a large scale is still a major challenge. This is particularly a problem when the production of low-value products is intended. Chemical flocculation, followed by sedimentation, is seen as an alternative method to improve the energetic and economic balance of the harvesting step. In this study, inorganic (aluminum sulfate, ferric sulfate, ferric chloride) and organic (Zetag 8185, chitosan, Tanfloc SG) flocculants were tested to harvest Chlorella vulgaris in batch mode. Preliminary assays were conducted to determine the minimum dosages of each flocculant that generates primary flocs at different pH. Except for chitosan, the organic flocculants required small dosages to initiate floc formation. Additional studies were performed for the flocculants with a better performance in the preliminary assays. Zetag 8185 had the best results, reaching 98.8% and 97.9% efficiencies with dosages of 50 and 100 mg L-1, respectively. Lastly, a 2(4) full factorial design experiment was performed to determine the effects of the flocculant dosage, settling time, and mixing time on the Zetag 8185 harvesting efficiency. The harvesting efficiency of C. vulgaris was optimal at a dosage of 100 mg L-1 and 3 min of rapid mixing

Biological effects of soft denture reline materials on L929 cells in vitro.

Soft denture reline materials have been developed to help patients when their oral mucosa is damaged or affected due to ill-fitting dentures or post-implant surgery. Although reports have indicated that these materials leach monomers and other components that do affect their biocompatibility, there is little information on what cell molecules may be implicated in these material/tissue interactions. The biocompatibility of six soft liners (Ufi Gel P, Sofreliner S, Durabase Soft, Trusoft, Softone and Coe Comfort) was evaluated using a mouse fibroblast cell line, L929. Within 2 h of material disc preparation, each of the materials was exposed by direct contact to L929 cells for periods of 24 and 48 h. The effect of this interaction was assessed by alamarBlue assay (for cell survival). The expression of integrin α5β1 and transforming growth factor β1 was also assessed using plate assays such as enzyme-linked immunosorbent assay. Trusoft, Softone and Coe Comfort showed significantly reduced cell survival compared with the other soft lining materials at each incubation period. Furthermore, there were significant differences with these same materials in the expression of both integrin α5β1 and transforming growth factor β1. Soft liner materials may affect cell viability and cellular proteins that have important roles in wound healing and the preservation of cell viability and function in the presence of environmental challenges and stresses

Current Practice of Imaging-Guided Interventional Procedures in Rheumatic and Musculoskeletal Diseases: Results of a Multinational Multidisciplinary Survey

Objectives: To investigate opinion and routine practice of specialists from different disciplines on imaging techniques for interventional procedures related to rheumatic and musculoskeletal diseases (RMDs). Methods: An English-language questionnaire was developed by an international working group and distributed to health care providers of various disciplines involved in the care of people with RMDs via an online survey tool (SoSci Survey®) from December 2019 to May 2020. Results: A total of 1,105 respondents from 56 countries completed the survey, over 60% of participants were rheumatologists. The majority of respondents (88%) performed interventional procedures in RMDs patients and 90% of them used imaging guidance. Ultrasonography was the most frequently used technique, particularly among rheumatologists. X-ray and computed tomography were mainly used by radiologists. A discrepancy emerged between the importance assigned to certain items such as the availability of a second operator and their actual implementation in clinical practice. Local barriers, lack of resources and facilities were mentioned as the most relevant obstacles in this regard. Lack of training on imaging and/or imaging guided procedures did not emerge as a barrier to perform such interventions; in fact, 19% of respondents performing the procedures indicated not to have received adequate training in this field. Conclusions: This is the first multinational multidisciplinary survey exploring in detail the opinions and practice on imaging guidance for interventional procedures in RMDs. A harmonization of protocols based on international guidelines, along with adequate training programmes and interventions on barriers at national/local levels are the main unmet needs requiring attention

Ultra-processed food consumption and obesity in the Australian adult population

Background: Rapid simultaneous increases in ultra-processed food sales and obesity prevalence have been observed worldwide, including in Australia. Consumption of ultra-processed foods by the Australian population was previously shown to be systematically associated with increased risk of intakes of nutrients outside levels recommended for the prevention of obesity. This study aims to explore the association between ultra-processed food consumption and obesity among the Australian adult population and stratifying by age group, sex and physical activity level. Methods: A cross-sectional analysis of anthropometric and dietary data from 7411 Australians aged ≥20 years from the National Nutrition and Physical Activity Survey 2011–2012 was performed. Food consumption was evaluated through 24-h recall. The NOVA system was used to identify ultra-processed foods, i.e. industrial formulations manufactured from substances derived from foods and typically added of flavours, colours and other cosmetic additives, such as soft drinks, confectionery, sweet or savoury packaged snacks, microwaveable frozen meals and fast food dishes. Measured weight, height and waist circumference (WC) data were used to calculate the body mass index (BMI) and diagnosis of obesity and abdominal obesity. Regression models were used to evaluate the association of dietary share of ultra-processed foods (quintiles) and obesity indicators, adjusting for socio-demographic variables, physical activity and smoking. Results: Significant (P-trend ≤ 0.001) direct dose–response associations between the dietary share of ultra-processed foods and indicators of obesity were found after adjustment. In the multivariable regression analysis, those in the highest quintile of ultra-processed food consumption had significantly higher BMI (0.97 kg/m2; 95% CI 0.42, 1.51) and WC (1.92 cm; 95% CI 0.57, 3.27) and higher odds of having obesity (OR = 1.61; 95% CI 1.27, 2.04) and abdominal obesity (OR = 1.38; 95% CI 1.10, 1.72) compared with those in the lowest quintile of consumption. Subgroup analyses showed that the trend towards positive associations for all obesity indicators remained in all age groups, sex and physical activity level. Conclusion: The findings add to the growing evidence that ultra-processed food consumption is associated with obesity and support the potential role of ultra-processed foods in contributing to obesity in Australia

Estudio bibliométrico de la investigación educativa en las universidades de Andalucía en el SSCI (2002-2010)

The ten Andalusian public universities have a total figure of 1312 professors linked to departments related to educational research. According to this, it could be said that there are enough research staff to make educational scientific production visible. Despite the fact that there are previous studies on Spanish educational production, these are not focused in Andalusia as a whole. The goal is to analyse the educational production, indexed in the Social Sciences Citation Index database (SSCI), carried out by researchers affiliated to some of the Andalusian universities. In particular, we analyse co-authorship patterns, diachronic production, language of the publication and the production per university. We utilize usual bibliometrical techniques for collecting and analysing data. We make the search in the SSCI from which we filter the information and download it. We used a local relational database made for this purpose. A standardization process of the author name and institution was made. An exponential rise of the production analysed is observed, partially due to the increment of educational journals that are indexed by the SSCI along the period studied. Spanish journals have the highest production rate. Likewise, a collaboration networks between Andalusian universities and others was revealed. The research articles are the 89.7% of the whole production analysed. The resulting collaboration index is slightly higher than others found in previous studies in the fields of Social Sciences and Education. In addition, it is shown that the collaboration among the Andalusian universities is low

Quantification and viability analyses of Pseudokirchneriella subcapitata algal cells using image-based cytometry

This work aims to evaluate the feasibility of using image-based cytometry (IBC) in the analysis of algal cell quantification and viability, using Pseudokirchneriella subcapitata as a cell model. Cell concentration was determined by IBC to be in a linear range between 1×105 and 8×106 cells mL1. Algal viability was defined on the basis that the intact membrane of viable cells excludes the SYTOX Green (SG) probe. The disruption of membrane integrity represents irreversible damage and consequently results in cell death. Using IBC, we were able to successfully discriminate between live (SG-negative cells) and dead algal cells (heat-treated at 65 °C for 60 min; SG-positive cells). The observed viability of algal populations containing different proportions of killed cells was well correlated (R 2=0.994) with the theoretical viability. The validation of the use of this technology was carried out by exposing algal cells of P. subcapitata to a copper stress test for 96 h. IBC allowed us to follow the evolution of cell concentration and the viability of copper-exposed algal populations. This technology overcomes several main drawbacks usually associated with microscopy counting, such as labour-intensive experiments, tedious work and lack of the representativeness of the cell counting. In conclusion, IBC allowed a fast and automated determination of the total number of algal cells and allowed us to analyse viability. This technology can provide a useful tool for a wide variety of fields that utilise microalgae, such as the aquatic toxicology and biotechnology fields.FCT Strategic Project PEst- OE/EQB/LA0023/2013. The post-doctoral grant from FCT (SFRH/BPD/72816/2010)

The Genomics of Speciation in Drosophila: Diversity, Divergence, and Introgression Estimated Using Low-Coverage Genome Sequencing

In nature, closely related species may hybridize while still retaining their distinctive identities. Chromosomal regions that experience reduced recombination in hybrids, such as within inversions, have been hypothesized to contribute to the maintenance of species integrity. Here, we examine genomic sequences from closely related fruit fly taxa of the Drosophila pseudoobscura subgroup to reconstruct their evolutionary histories and past patterns of genic exchange. Partial genomic assemblies were generated from two subspecies of Drosophila pseudoobscura (D. ps.) and an outgroup species, D. miranda. These new assemblies were compared to available assemblies of D. ps. pseudoobscura and D. persimilis, two species with overlapping ranges in western North America. Within inverted regions, nucleotide divergence among each pair of the three species is comparable, whereas divergence between D. ps. pseudoobscura and D. persimilis in non-inverted regions is much lower and closer to levels of intraspecific variation. Using molecular markers flanking each of the major chromosomal inversions, we identify strong crossover suppression in F1 hybrids extending over 2 megabase pairs (Mbp) beyond the inversion breakpoints. These regions of crossover suppression also exhibit the high nucleotide divergence associated with inverted regions. Finally, by comparison to a geographically isolated subspecies, D. ps. bogotana, our results suggest that autosomal gene exchange between the North American species, D. ps. pseudoobscura and D. persimilis, occurred since the split of the subspecies, likely within the last 200,000 years. We conclude that chromosomal rearrangements have been vital to the ongoing persistence of these species despite recent hybridization. Our study serves as a proof-of-principle on how whole genome sequencing can be applied to formulate and test hypotheses about species formation in lesser-known non-model systems

Protein interactions in Xenopus germ plasm RNP particles

Hermes is an RNA-binding protein that we have previously reported to be found in the ribonucleoprotein (RNP) particles of Xenopus germ plasm, where it is associated with various RNAs, including that encoding the germ line determinant Nanos1. To further define the composition of these RNPs, we performed a screen for Hermes-binding partners using the yeast two-hybrid system. We have identified and validated four proteins that interact with Hermes in germ plasm: two isoforms of Xvelo1 (a homologue of zebrafish Bucky ball) and Rbm24b and Rbm42b, both RNA-binding proteins containing the RRM motif. GFP-Xvelo fusion proteins and their endogenous counterparts, identified with antisera, were found to localize with Hermes in the germ plasm particles of large oocytes and eggs. Only the larger Xvelo isoform was naturally found in the Balbiani body of previtellogenic oocytes. Bimolecular fluorescence complementation (BiFC) experiments confirmed that Hermes and the Xvelo variants interact in germ plasm, as do Rbm24b and 42b. Depletion of the shorter Xvelo variant with antisense oligonucleotides caused a decrease in the size of germ plasm aggregates and loosening of associated mitochondria from these structures. This suggests that the short Xvelo variant, or less likely its RNA, has a role in organizing and maintaining the integrity of germ plasm in Xenopus oocytes. While GFP fusion proteins for Rbm24b and 42b did not localize into germ plasm as specifically as Hermes or Xvelo, BiFC analysis indicated that both interact with Hermes in germ plasm RNPs. They are very stable in the face of RNA depletion, but additive effects of combinations of antisense oligos suggest they may have a role in germ plasm structure and may influence the ability of Hermes protein to effectively enter RNP particles