198 research outputs found
The chemoreceptor genes of the waterflea Daphnia pulex: many Grs but no Ors
<p>Abstract</p> <p>Background</p> <p>Chemoreception is vitally important for all animals, yet little is known about the genetics of chemoreception in aquatic organisms. The keystone species <it>Daphnia pulex</it>, a well known crustacean, is the first aquatic invertebrate to have its genome sequenced. This has allowed us the initial investigation of chemoreceptor genes in an aquatic invertebrate, and to begin the study of chemoreceptor evolution across the arthropod phylum.</p> <p>Results</p> <p>We describe 58 Grs (gustatory receptors), belonging to the insect chemoreceptor superfamily, which were identified bioinformatically in the draft genome of the crustacean waterflea <it>Daphnia pulex</it>. No genes encoding proteins similar to the insect odorant receptors (Ors) were identified. These 58 Grs form 3 distinctive subfamilies of 37, 12, and 5 genes, as well as a highly divergent singleton (Gr58). In addition, Grs55–57 share distinctive amino acid motifs and cluster with the sugar receptors of insects, and may illuminate the origin of this distinctive subfamily. ESTs, tiling array, and PCR amplification results support 34 predicted gene models, and preliminary expression data comparing the sexes indicates potential female-biased expression for some genes.</p> <p>Conclusion</p> <p>This repertoire of 58 chemoreceptors presumably mediates the many chemoperception abilities of waterfleas. While it is always possible that the entire Or gene lineage was lost at some point in the history of <it>Daphnia pulex</it>, we think it more likely that the insect Or lineage is indeed a relatively recently expanded gene lineage concomitant with the evolution of terrestriality in the insects or their hexapod ancestors.</p
Utilization of recycled polypropylene, cellulose and newsprint fibres for production of green composites
This work investigates the feasibility of using the recycled polypropylene (rPP), cellulose (CF) and newsprint (NP) fibres in polyolefin reinforced composites. Recycled PP filled with 40 wt.% of cellulose (rPP/CF) or newsprint (rPP/NP), with the addition of impact modifier (IM) and compatibilizing agent (CA), have been prepared with ex-trusion melting and injection moulding. Melting and crystallization behaviour of plain matrix and composites were measured by differential scanning calorimetry (DSC). Morphological and mechanical properties were also studied using scanning electron microscope (SEM) and tensile testing, respectively. Thermal stability of composites was similar to neat rPP for both types of the filler used. Though, the crystallinity was progressively decreased with the addition of CF or NP. The DSC further revealed an occurrence of the two distinct melting transitions, meaning that the examined materials were not based on pure polypropylene (PP), but are rather blends of high-density polyethylene (HDPE) and PP, what has been confirmed also by the Fourier transform infrared spectroscopy (FTIR). The largest single source of contaminations in recycled PP comes from HDPE since both polymers are identified by a similar density and can be accidentally mixed during the conventional physical separation process. Composites reinforced with CF have shown better mechanical performances than those based on reclaimed NP fibres, what can be attributed to the initial fibre quality. Tensile strength of the composites filled with CF and NP fibres was 36 MPa and 29 MPa, respectively, in disparity to 23 MPa measured for neat rPP. The fibre addition further resulted in substantial increase in Young modulus of the composites. The addition of CF and NP fibres lead to an improved modulus of elasticity by 16 and 47%, respectively. Waste paper in the form of recovered cellulose or reclaimed newsprint fibre can thus meet all the technical requirements to become an alternative to inor-ganic fillers in thermoplastic composites
AntVideoRecord: Autonomous system to capture the locomotor activity of leafcutter ants
The leafcutter ants (LCA) are considered plague in a great part of the American continent,
causing great damage in production fields. Knowing the locomotion and foraging rhythm in
LCA on a continuous basis would imply a significant advance for ecological studies, fundamentally
of animal behavior. However, studying the forage rhythm of LCA in the field
involves a significant human effort. This also adds a risk of subjective results due to the
operator fatigue. In this work a new development named ‘AntVideoRecord’ is proposed
to address this issue. This device is a low-cost autonomous system that records videos of
the LCA path in a fixed position. The device can be easily reproduced using the freely accessible
source code provided. The evaluation of this novel device was successful because it
has exceeded all the basic requirements in the field: record continuously for at least seven
days, withstand high and low temperatures, capture acceptable videos during the day and
night, and have a simple configuration protocol by mobile devices and laptops. It was possible
to confirm the correct operation of the device, being able to record more than 1900 h
in the field at different climate conditions and times of the day.
2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CCANII: FMV 15605
Mitochondrial membrane models built from native lipid extracts: Interfacial and transport properties
The mitochondrion is an essential organelle enclosed by two membranes whose functionalities depend on their very specific protein and lipid compositions. Proteins from the outer mitochondrial membrane (OMM) are specialized in mitochondrial dynamics and mitophagy, whereas proteins of the inner mitochondrial membrane (IMM) have dedicated functions in cellular respiration and apoptosis. As for lipids, the OMM is enriched in glycerophosphatidyl choline but cardiolipin is exclusively found within the IMM. Though the lipid topology and distribution of the OMM and IMM are known since more than four decades, little is known about the interfacial and dynamic properties of the IMM and OMM lipid extracts. Here we build monolayers, supported bilayers and giant unilamellar vesicles (GUVs) of native OMM and IMM lipids extracts from porcine heart. Additionally, we perform a comparative analysis on the interfacial, phase immiscibility and mechanical properties of both types of extract. Our results show that IMM lipids form more expanded and softer membranes than OMM lipids, allowing a better understanding of the physicochemical and biophysical properties of mitochondrial membranes.Fil: Schiaffarino, Olivia. Universidad Complutense de Madrid; EspañaFil: Valdivieso González, David. Hospital Universitario 12 de Octubre; España. Universidad Complutense de Madrid; EspañaFil: García Pérez, Inés M.. Universidad Complutense de Madrid; EspañaFil: Peñalva, Daniel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur; ArgentinaFil: Almendro Vedia, Víctor G.. Universidad Complutense de Madrid; España. Hospital Doce de Octubre, Madrid; EspañaFil: Natale, Paolo. Universidad Complutense de Madrid; España. Hospital Universitario 12 de Octubre; EspañaFil: López Montero, Iván. Universidad Complutense de Madrid; España. Hospital Universitario 12 de Octubre; Españ
Robocasting of dense 8Y zirconia parts: Rheology, printing, and mechanical properties
Advanced ceramics with complex geometry have become indispensable in engineering applications. Due to limitations of traditional ceramic fabrication processes, additive manufacturing represents a revolution for shaping and consolidation because of its unique capabilities for increasing shape complexity and reducing waste material. Among the additive manufacturing techniques, robocasting is often considered to yield fine and dense ceramic structures with geometrically complex morphology and high strength. Within this context, it is the objective to attain dense 8 mol% yttria-stabilized zirconia (8Y-ZrO2) by evaluating the influence of solid loading and filament orientation on the physical and mechanical properties of sintered parts. In doing so, a printable ink was developed using an inverse-thermoresponsive hydrogel. Results revealed that ceramic charges of 67.5 and 70 wt% achieved the best balance regarding density, hardness, and compression strength. Furthermore, rectilinear geometry with a filament orientation at 45º displayed higher mechanical response than 0/90º and cylindrical ones.Peer ReviewedPostprint (published version
Disease severity in familial cases of IBD
Background: Phenotypic traits of familial IBD relative to sporadic cases are controversial, probably related to limited statistical power of published evidence.
Aim: To know if there are phenotype differences between familial and sporadic IBD, evaluating the prospective Spanish registry (ENEIDA) with 11,983 cases.
Methods: 5783 patients (48.3%) had ulcerative colitis (UC) and 6200 (51.7%) Crohn's disease (CD). Cases with one or more 1st, 2nd or 3rd degree relatives affected by UC/CD were defined as familial case.
Results: In UC and CD, familial cases compared with sporadic cases had an earlier disease onset (UC: 33 years [IQR 25–44] vs 37 years [IQR 27–49]; p b 0.0001); (CD: 27 years [IQR 21–35] vs 29 years [IQR 22–40]; p b 0.0001), higher prevalence of extraintestinal immune-related manifestations (EIMs) (UC: 17.2% vs 14%; p = 0.04); (CD: 30.1% vs 23.6%; p b 0.0001). Familial CD had higher percentage of ileocolic location (42.7% vs 51.8%; p = 0.0001), penetrating behavior (21% vs 17.6%; p = 0.01) and perianal disease (32% vs 27.1%; p = 0.003). Differences are not influenced by degree of consanguinity.
Conclusion: When a sufficiently powered cohort is evaluated, familial aggregation in IBD is associated to an earlier disease onset, more EIMs and more severe phenotype in CD. This feature should be taken into account at establishing predictors of disease course
New interfacial microtubule inhibitors of marine origin, PM050489/PM060184, with potent antitumor activity and a distinct mechanism
We have investigated the target and mechanism of action of a new family of cytotoxic small molecules of marine origin. PM050489 and its dechlorinated analogue PM060184 inhibit the growth of relevant cancer cell lines at subnanomolar concentrations. We found that they are highly potent microtubule inhibitors that impair mitosis with a distinct molecular mechanism. They bind with nanomolar affinity to unassembled αβ-tubulin dimers, and PM050489 binding is inhibited by known Vinca domain ligands. NMR TR-NOESY data indicated that a hydroxyl-containing analogue, PM060327, binds in an extended conformation, and STD results define its binding epitopes. Distinctly from vinblastine, these ligands only weakly induce tubulin self-association, in a manner more reminiscent of isohomohalichondrin B than of eribulin. PM050489, possibly acting like a hinge at the association interface between tubulin heterodimers, reshapes Mg2+-induced 42 S tubulin double rings into smaller 19 S single rings made of 7 ± 1 αβ-tubulin dimers. PM060184-resistant mutants of Aspergillus nidulans map to β-tubulin Asn100, suggesting a new binding site different from that of vinblastine at the associating β-tubulin end. Inhibition of assembly dynamics by a few ligand molecules at the microtubule plus end would explain the antitumor activity of these compounds, of which PM060184 is undergoing clinical trials.We wish to thank J. M. Fernandez Sousa (PharmaMar) for useful discussions and support, E. Hamel (NCI) for providing eribulin, C. Scazzocchio and G. Diallinas for useful advice on mutant screening, H. N. Arst for advice on mutant screening and mapping and for kindly providing strains MAD3688 and MAD4655, T. J. Fitzgerald (A&M University) for MTC and C. Alfonso (CIB) for AUC analysis. We also thank Rhône Poulenc Rorer Aventis for supplying docetaxel and Matadero Municipal Vicente de Lucas de Segovia for providing the calf brains for tubulin purification. B.P. had a contract from Comunidad de Madrid, and A.C. had a Ramon y Cajal contract, J.R.-S. had a fellowship from “Programa de Cooperación Científica entre el Ministerio de Ciencia, Tecnologías y Medio Ambiente de la República de Cuba (CITMA) y el CSIC”. This work was supported by grants BIO2010-16351 (J.F.D.), BQU2009-08536 (J.J.-B.), CAM S2010/BMD-2457 (J.F.D.), CAM S2010/BMD-2353 (J.J.-B., J.M.A.), IPT-2011-0752-900000 and BIO2012-30965 (M.A.P.), BFU2011-23416 (J.M.A.) and PharmaMar-CSIC contracts
Current challenges of research on filamentous fungi in relation to human welfare and a sustainable bio-economy: a white paper.
The EUROFUNG network is a virtual centre of multidisciplinary expertise in the field of fungal biotechnology. The first academic-industry Think Tank was hosted by EUROFUNG to summarise the state of the art and future challenges in fungal biology and biotechnology in the coming decade. Currently, fungal cell factories are important for bulk manufacturing of organic acids, proteins, enzymes, secondary metabolites and active pharmaceutical ingredients in white and red biotechnology. In contrast, fungal pathogens of humans kill more people than malaria or tuberculosis. Fungi are significantly impacting on global food security, damaging global crop production, causing disease in domesticated animals, and spoiling an estimated 10 % of harvested crops. A number of challenges now need to be addressed to improve our strategies to control fungal pathogenicity and to optimise the use of fungi as sources for novel compounds and as cell factories for large scale manufacture of bio-based products. This white paper reports on the discussions of the Think Tank meeting and the suggestions made for moving fungal bio(techno)logy forward
Encapsulation of Lactobacillus plantarum in casein-chitosan microparticles facilitates the arrival to the colon and develops an immunomodulatory effect
The current work describes the capability of casein-chitosan microparticles to encapsulate Lactobacillus plantarum
(CECT 220 and WCFS1 strains) and evaluates their ability to target the distal areas of the gut and to stimulate the
immune system. Microparticles were prepared by complex coacervation, between sodium caseinate and chitosan
in an aqueous suspension of the bacteria, and dried by spray-drying. In order to increase the survival rate of the
loaded bacteria, microparticles were cross-linked with one of the following cross-linkers: tripolyphosphate,
calcium salts or vanillin.
Overall, microparticles displayed a mean size of about 7.5 μm with a bacteria loading of about 11 Log CFU/g,
when cross-linked with vanillin (MP-LP-V). For conventional microparticles, the payload was 10.12 Log CFU/g.
The storage stability study at 25 ◦C/60% RH, MP-LP-V offered the highest degree of protection without signif-
icant modification of the payload in 260 days. Compared with control (aqueous suspension of bacteria), MP-LP-V
also displayed a significantly higher degree of protection against probiotic inactivation in simulated gastric and
intestinal fluids. In vivo results evidenced that microparticles, orally administered to rats, were able to reach the
distal ileum and colon in about 4 h post-administration. Additionally, the effect of the daily administration of
107 CFU/mouse of MP-LP-V, for 3 weeks, induced an immunomodulatory effect characterized by an important
enhancement of Th1 and Th17 responses. In conclusion, these microparticles seem to be a promising strategy for
increasing survival and efficacy of probiotics, allowing the formulation of cost-effective and more stable and
effective probiotic-based nutraceuticals
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