Evaluation of xylanases from Aspergillus niger and Trichoderma sp. on dough rheological properties

Although starch is the main polysaccharide used in the fermentation of bread dough, wheat flour also contain some non-starch polysaccharides such as pentosans or hemicelluloses, which may contribute up to 3% of the total polysaccharide content of the flour. Despite being present in relatively low amounts, pentosans and hemicelluloses play an important role in dough rheology and bread properties. The aim of this work is to understand how the xylanases from Aspergillus niger and Trichoderma sp. influence dough rheology, such as elasticity, extensibility, strength and stability. When the extensograph parameters such as extensibility (E) and elasticity (R) were determined, it was possible to note that all dosages of xylanase from A. niger were capable of decreasing the dough elasticity in 21%. Depending on the dosage, the xylanase from Trichoderma sp. can decrease dough stability in the mixing and, consequently, the mixing time during the process. An increased dosage of Trichoderma xylanase decreased the elasticity in 32% and increased the extensibility by 8% following 45 min. It was also observed that raising dosages of Trichoderma xylanase in flour content affected the dough rheology more significantly than raising dosages of A. niger xylanase.Key words: Xylanase, dough rheological properties, bread, Aspergillus niger, Trichoderma sp

Techniques of intestinal transplantation in rat

Two surgical models of intestinal transplantation in the rat are described. One is the implantation of fetal and newborn intestine as free grafts into the omentum of adult recipients, the other the adult intestine transplantation as an accessory graft using vascular anastomoses. A hundred and sixteen small-bowel transplantations were done; 36 of which were fetal intestine (group I), 40 of newborn intestine (group II), and 40 of adult intestine (group III). In the fetal and newborn intestinal transplantation, we emphasize the practices that allowed us to avoid ischemic and traumatic injury to the graft. In the adult intestine transplantation with vascular anastomoses, we heighten the modifications in the surgical technique that made the operation easier and the strategies used to prevent hypothermia and hypovolemic shock. Once experienced with the two chosen surgical techniques, transplantation using an avascular segment became much easier and quicker than transplantation with vascular anastomose

Evolutionary Constraints in the b-Globin Cluster: The Signature of Purifying Selection at the d-Globin (HBD) Locus and Its Role in Developmental Gene Regulation

Human hemoglobins, the oxygen carriers in the blood, are composed by two α-like and two β-like globin monomers. The β-globin gene cluster located at 11p15.5 comprises one pseudogene and five genes whose expression undergoes two critical switches: the embryonic-to-fetal and fetal-to-adult transition. HBD encodes the δ-globin chain of the minor adult hemoglobin (HbA2), which is assumed to be physiologically irrelevant. Paradoxically, reduced diversity levels have been reported for this gene. In this study, we sought a detailed portrait of the genetic variation within the β-globin cluster in a large human population panel from different geographic backgrounds. We resequenced the coding and noncoding regions of the two adult β-globin genes (HBD and HBB) in European and African populations, and analyzed the data from the β-globin cluster (HBE, HBG2, HBG1, HBBP1, HBD, and HBB) in 1,092 individuals representing 14 populations sequenced as part of the 1000 Genomes Project. Additionally, we assessed the diversity levels in nonhuman primates using chimpanzee sequence data provided by the PanMap Project. Comprehensive analyses, based on classic neutrality tests, empirical and haplotype-based studies, revealed that HBD and its neighbor pseudogene HBBP1 have mainly evolved under purifying selection, suggesting that their roles are essential and nonredundant. Moreover, in the light of recent studies on the chromatin conformation of the β-globin cluster, we present evidence sustaining that the strong functional constraints underlying the decreased contemporary diversity at these two regions were not driven by protein function but instead are likely due to a regulatory role in ontogenic switches of gene expression

Leadership During a Pandemic: A Lexical Analysis

To manage pandemics, like COVID-19, leadership can enable health services to weather the storm. Yet there is limited clarity on how leadership manifested and was discussed in the literature during COVID-19. This can have considerable public health implications given the importance of leadership in the health sector. This article addresses this missed opportunity by examining the literature on leadership during a pandemic. Following a systematic search of nine academic databases in May 2021, 1,747 publications were screened. Following this, a lexical analysis of the results section was conducted, sourced from a corpus of publications across myriad journals. The results found a prevalence of references to “leader” as a sole actor, risking the perpetuation of a view that critical decisions emanate from a singular source. Moreover, “leadership” was a concept disconnected from the fray of frontline workers, patients, and teams. This suggests a strong need for more diverse vocabularies and conceptions that reflect the “messiness” of leadership as it takes shape in relation to the challenges and uncertainties of COVID-19. There is a considerable opportunity to advance scholarship on leadership via further empirical studies that help to clarify different approaches to lead teams and organizations during a pandemic.</jats:p

Spatially explicit analysis reveals complex human genetic gradients in the Iberian Peninsula

The Iberian Peninsula is a well-delimited geographic region with a rich and complex human history. However, the causes of its genetic structure and past migratory dynamics are not yet fully understood. In order to shed light on them, here we evaluated the gene flow and genetic structure throughout the Iberian Peninsula with spatially explicit modelling applied to a georeferenced genetic dataset composed of genome-wide SNPs from 746 individuals belonging to 17 different regions of the Peninsula. We found contrasting patterns of genetic structure throughout Iberia. In particular, we identified strong patterns of genetic differentiation caused by relevant barriers to gene flow in northern regions and, on the other hand, a large genetic similarity in central and southern regions. In addition, our results showed a preferential north to south migratory dynamics and suggest a sex-biased dispersal in Mediterranean and southern regions. The estimated genetic patterns did not fit with the geographical relief of the Iberian landscape and they rather seem to follow political and linguistic territorial boundaries.IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). J.P. and A.M.L. are funded by the Portuguese Government through the FCT fellowship SFRH/BD/97200/2013 and the research contract IF/01262/2014, respectively. M.A. was supported by the “Ramón y Cajal” grant RYC-2015-18241 from the Spanish Government. D.C. was supported by the Spanish grant CGL2016-75389-P (AEI, MINEICO/FEDER, UE), and “Unidad María de Maeztu” funded by the MINECO (MDM-2014-0370)

New combined CFH/MCP mutations and a rare clinical course in atypical haemolytic uraemic syndrome

Atypical haemolytic uraemic syndrome (aHUS) is a rare, life-threatening, chronic, genetic disease due to uncontrolled alternative pathway complement activation. In this report, we discuss the case of a heterozygous carrier of a mutation on both factor H and membrane cofactor protein, who persistently presents haemolytic anaemia without need for blood transfusions, normal platelet count, normal renal function and no signs or symptoms of organ injury due to thrombotic microangiopathy 4 years after the diagnosis of aHUS.info:eu-repo/semantics/publishedVersio

Testing the Coulomb/Accessible Surface Area solvent model for protein stability, ligand binding, and protein design

<p>Abstract</p> <p>Background</p> <p>Protein structure prediction and computational protein design require efficient yet sufficiently accurate descriptions of aqueous solvent. We continue to evaluate the performance of the Coulomb/Accessible Surface Area (CASA) implicit solvent model, in combination with the Charmm19 molecular mechanics force field. We test a set of model parameters optimized earlier, and we also carry out a new optimization in this work, using as a target a set of experimental stability changes for single point mutations of various proteins and peptides. The optimization procedure is general, and could be used with other force fields. The computation of stability changes requires a model for the unfolded state of the protein. In our approach, this state is represented by tripeptide structures of the sequence Ala-X-Ala for each amino acid type X. We followed an iterative optimization scheme which, at each cycle, optimizes the solvation parameters and a set of tripeptide structures for the unfolded state. This protocol uses a set of 140 experimental stability mutations and a large set of tripeptide conformations to find the best tripeptide structures and solvation parameters.</p> <p>Results</p> <p>Using the optimized parameters, we obtain a mean unsigned error of 2.28 kcal/mol for the stability mutations. The performance of the CASA model is assessed by two further applications: (i) calculation of protein-ligand binding affinities and (ii) computational protein design. For these two applications, the previous parameters and the ones optimized here give a similar performance. For ligand binding, we obtain reasonable agreement with a set of 55 experimental mutation data, with a mean unsigned error of 1.76 kcal/mol with the new parameters and 1.47 kcal/mol with the earlier ones. We show that the optimized CASA model is not inferior to the Generalized Born/Surface Area (GB/SA) model for the prediction of these binding affinities. Likewise, the new parameters perform well for the design of 8 SH3 domain proteins where an average of 32.8% sequence identity relative to the native sequences was achieved. Further, it was shown that the computed sequences have the character of naturally-occuring homologues of the native sequences.</p> <p>Conclusion</p> <p>Overall, the two CASA variants explored here perform very well for a wide variety of applications. Both variants provide an efficient solvent treatment for the computational engineering of ligands and proteins.</p

Biomarkers of Thermal Adaptation: New Tools in Sustainable Livestock Production under Climate Change

Climate changes have been identified as one of the greatest environmental, social and economic threats to the planet and humanity. The increase of extreme weather events, such as prolonged droughts, extreme ambient temperatures or periods with high and intensive precipitation has effects on animal production systems. Crops, and consequently forage productivity and availability are compromised, the risk of new diseases increase, and animal production is impaired (growth, reproductive performance, metabolic and health status, and immune response can be affected). In this way the development of resilient and robust animal production systems, together with an improvement in the knowledge of the environmental impact in animal production and welfare are crucial to enhance innovation, sustainability and productivity in the animal sector. Ambient temperature and its abrupt extreme events have a major impact on the energy metabolism of livestock. This implies that animals presenting more physiological versatility can be best adapted, and therefore less susceptible to thermal stress and more productive. To achieve a production system where the detrimental effect of the climate change can be the minimum is necessary to improve the ability of the animal to cope with environmental stress by management and selection. The existence of biomarkers that allow to identify the levels of thermal stress and/or acclimation are valuable in the process of selecting the best well suited animals for each environmental condition, to propose selection programs based on that and for the herds management. Ideally biomarkers should be obtained from readily accessible samples, preferably non-invasively or minimally invasive, such as saliva, sweat and milk, hair and feces. Nowadays, the most commonly fluid used in biomarkers studies is the blood/plasma, but with growing tendency for being replaced. Blood cortisol has been one of the parameters more frequently used for assessing stressful conditions such as thermal stress. Nevertheless, it does not allow a full understanding of heat stress, due to its circadian cycle and because the confounding with other types of stress. Moreover, and taking the advantage of saliva as a non-invasive source of this corticosteroid, salivary cortisol has been also referred as potentially interesting. However, some of the limitations in taking conclusions from salivary cortisol results are the same reported for blood cortisol. Consequently, new and better non-invasive methods, than allow assessing stress, are necessary. The aim of this chapter is to present the state of the art on stress responses (climate, housing) and the principal effects of great temperature amplitudes in livestock production and the existing means to evaluate heat stress and acclimation capacity. Focus will be put on the importance of new reliable biomarkers. Saliva, hair, milk and feces will be discussed as potential sources of such non-invasive biomarkers

Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers

This work was supported by the Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grants E-26/202.974/2015 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grants 229755/2013-5, Brazil. LMLB is a senior research fellow of CNPq and Faperj. NG acknowledged support from the Wellcome Trust (Trust (097377, 101873, 200208) and MRC Centre for Medical Mycology (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD