1,561 research outputs found
Beeswax organogels: Influence of gelator concentration and oil type in the gelation process
This work focused on how different types of oil phase, MCT (medium chain triglycerides) and LCT (long chain triglycerides), exert influence on the gelation process of beeswax and thus properties of the organogel produced thereof. Organogels were produced at different temperatures and qualitative phase diagrams were constructed to identify and classify the type of structure formed at various compositions. The microstructure of gelator crystals was studied by polarized light microscopy. Melting and crystallization were characterized by differential scanning calorimetry and rheology (flow and small amplitude oscillatory measurements) to understand organogels' behaviour under different mechanical and thermal conditions. FTIR analysis was employed for a further understanding of oil-gelator chemical interactions. Results showed that the increase of beeswax concentration led to higher values of storage and loss moduli (G, G) and complex modulus (G*) of organogels, which is associated to the strong network formed between the crystalline gelator structure and the oil phase. Crystallization occurred in two steps (well evidenced for higher concentrations of gelator) during temperature decreasing. Thermal analysis showed the occurrence of hysteresis between melting and crystallization. Small angle X-ray scattering (SAXS) analysis allowed a better understanding in terms of how crystal conformations were disposed for each type of organogel. The structuring process supported by medium or long-chain triglycerides oils was an important exploit to apprehend the impact of different carbon chain-size on the gelation process and on gels' properties.The authors thank the Brazilian Synchrotron Light Laboratory (LNLS,
Campinas, SP, Brazil) for the opportunity to carry out SAXS measurements.
The author Miguel A. Cerqueira is recipient of a fellowship (SFRH/BPD/72753/2010) supported by Fundação para a Ciência e a Tecnologia, POPH-QREN and FSE (FCT, Portugal). The financial support
of CAPES/FCT Project “Nanotechnological systems based in biocompatible ingredients: characterization, controlled release and in vitro digestion” (CAPES/FCT no. 348/13) and CNPq (Universal 479459/2012-6)
are gratefully acknowledged. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
Phage Display Technology in Biomaterials Engineering: Progress and Opportunities for Applications in Regenerative Medicine
This work was supported by national funds through the Portuguese Foundation for Science and Technology under the scope of the project PTDC/EBB-BIO/114523/2009 and by the European Regional Development Fund (ERDF) through the Operational Competitiveness Programme “COMPETE” (FCOMP-01-0124-FEDER-014758). The authors are also thankful for the financial support of the Portuguese Foundation for Science and Technology under the strategic funding of UID/ BIO/04469/2013 unit and RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the European Union under the Marie Curie Career Integration Grant SuprHApolymers (PCIG14-GA-2013-631871)
Low‐cost tools mitigate climate change during reproduction in an endangered marine ectotherm
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData Availability Statement:
Data available via the Dryad Digital Repository https://doi.org/10.5061/dryad.3r2280gfq. (Clarke et al., 2021)The impacts of anthropogenic climate change will be most dramatic for species that live in narrow thermal niches, such as reptiles. Given the imminent threat to biodiversity, and that actions to reduce carbon emissions are not yet sufficient, it is important that a sound evidence base of potential mitigation options is available for conservation managers.
Successful incubation and production of male sea turtle hatchlings is threatened by increased global temperatures (sex is determined by the temperature at which eggs incubate). Here we test two conservation tools to reduce incubation temperatures: clutch splitting and clutch shading, on a nesting loggerhead turtle (Caretta caretta) population in the Eastern Atlantic Ocean.
During the thermosensitive period of incubation, split and shaded clutches were both 1.00 ˚C cooler than control nests. Clutch splitting (mean: 45 eggs) reduced nest temperatures by reducing metabolic heating during incubation compared to controls (mean: 92 eggs). Modelled primary sex ratios differed between nest treatments, with 1.50 % (± 6 % S.E.) females produced in shaded nests, 45.00 % (± 7 % S.E.) females in split nests and 69.00 % (± 6% S.E.) females in controls. Neither treatment affected hatchling size, success, mass or vigour. When clutch splitting was repeated two years later, hatch success was higher in split clutches compared to controls.
Synthesis and Applications: Clutch splitting and clutch shading successfully altered the thermal profile of incubating turtle nests. When there is sufficient knowledge to better understand the effects of intervention on fundamental population demographics, they will be useful for reducing incubation temperatures in sea turtle nests, potentially increasing nest survival and male hatchling production. The effect of clutch splitting in reducing nest temperature was lower relative to clutch shading, but requires significantly less funding, materials and specialist skill, key factors for management of turtle rookeries that are often in remote, resource‐limited areas.Worldwide Fund for NatureWAVE Foundation of Newport Aquariu
Recovery following rugby union matches: Effects of cold water immersion on markers of fatigue and damage
© 2019, Canadian Science Publishing. All rights reserved. We investigated the effect of postmatch cold-water immersion (CWI) on markers of muscle damage, neuromuscular fatigue, and perceptual responses within 72 h after a rugby match. Twenty-two professional male rugby players were randomized into CWI (10 °C/10 min; n = 11) or control (CON: 30 min seated; n = 11) groups. Activity profile from Global Positioning Satellite systems and postmatch rating of perceived exertion were measured to determined match load. Biochemical (tumor necrosis factor alpha (TNF-α), interleukin-6), neuromuscular performance (squat (SJ) and countermovement jumps (CMJ), peak power output (PPO), rate of force development (RFD), stiffness, 10-and 30-m sprint time, and perceptual markers (soreness, perceived recovery) were obtained before and immediately after the match, and then at 30 min, 24 h, 48 h, and 72 h after the match. Magnitude-based inference and Cohen’s effect size (ES) were used to analyze change over time and between groups. Thus, the higher/beneficial, similar/trivial, or lower/harmful differences were evaluated as follows: 99%, almost certainly. Changes were unclear for the match loads, sprint times, and perceptual markers between groups. Higher %ΔSJ at 24 h (very likely (ES = 0.75)) and in %ΔPPO_SJ at 48 h (likely (ES = 0.51)) were observed in CWI than in CON. Values in %ΔRDF_CMJ were higher immediately after (likely (ES = 0.83)), 30 min after (very likely (ES = 0.97)), and 24 h after the match (likely (ES = 0.93)) in CWI than in CON. Furthermore, %Δlog TNF-α were lower in the CWI group than in the CON group immediately after (almost certainly (ES = −0.76)), 24 h after (very likely (ES = −1.09)), and 72 h after the match (likely (ES = −0.51)), and in Δstiffness_SJ at 30 min after (likely (ES = −0.67)) and 48 h after the match (very likely (ES = −0.97)). Also, different within-groups effects throughout postmatch were reported. Implementing postmatch CWI-based strategies improved the recovery of markers of inflammation and fatigue in rugby players, despite no change in markers of speed or perceptual recovery
Full Genome Characterization of the Culicoides-Borne Marsupial Orbiviruses: Wallal Virus, Mudjinbarry Virus and Warrego Viruses
Viruses belonging to the species Wallal virus and Warrego virus of the genus Orbivirus were identified as causative agents of blindness in marsupials in Australia during 1994/5. Recent comparisons of nucleotide (nt) and amino acid (aa) sequences have provided a basis for the grouping and classification of orbivirus isolates. However, full-genome sequence data are not available for representatives of all Orbivirus species. We report full-genome sequence data for three additional orbiviruses: Wallal virus (WALV); Mudjinabarry virus (MUDV) and Warrego virus (WARV). Comparisons of conserved polymerase (Pol), sub-core-shell 'T2' and core-surface 'T13' proteins show that these viruses group with other Culicoides borne orbiviruses, clustering with Eubenangee virus (EUBV), another orbivirus infecting marsupials. WARV shares <70% aa identity in all three conserved proteins (Pol, T2 and T13) with other orbiviruses, consistent with its classification within a distinct Orbivirus species. Although WALV and MUDV share <72.86%/67.93% aa/nt identity with other orbiviruses in Pol, T2 and T13, they share >99%/90% aa/nt identities with each other (consistent with membership of the same virus species - Wallal virus). However, WALV and MUDV share <68% aa identity in their larger outer capsid protein VP2(OC1), consistent with membership of different serotypes within the species - WALV-1 and WALV-2 respectively
Clinical and genetic analysis of 29 Brazilian patients with Huntington’s disease-like phenotype
Huntington’s disease (HD) is a neurodegenerative disorder characterized by chorea,
behavioral disturbances and dementia, caused by a pathological expansion of the CAG
trinucleotide in the HTT gene. Several patients have been recognized with the typical HD
phenotype without the expected mutation. The objective of this study was to assess the
occurrence of diseases such as Huntington’s disease-like 2 (HDL2), spinocerebellar ataxia
(SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and choreaacanthocytosis
(ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group
analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not
reached in 79.3% of the patients. HDL2 was the main cause of the HD-like phenotype in
the group analyzed, and is attributable to the African ancestry of this population. However,
the etiology of the disease remains undetermined in the majority of the HD negative
patients with HD-like phenotype.
Key words: Huntington’s disease, Huntington’s disease-like, chorea-acanthocytosis,
Huntington’s disease-like 2
Low‐cost tools mitigate climate change during reproduction in an endangered marine ectotherm
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData Availability Statement:
Data available via the Dryad Digital Repository https://doi.org/10.5061/dryad.3r2280gfq. (Clarke et al., 2021)The impacts of anthropogenic climate change will be most dramatic for species that live in narrow thermal niches, such as reptiles. Given the imminent threat to biodiversity, and that actions to reduce carbon emissions are not yet sufficient, it is important that a sound evidence base of potential mitigation options is available for conservation managers.
Successful incubation and production of male sea turtle hatchlings is threatened by increased global temperatures (sex is determined by the temperature at which eggs incubate). Here we test two conservation tools to reduce incubation temperatures: clutch splitting and clutch shading, on a nesting loggerhead turtle (Caretta caretta) population in the Eastern Atlantic Ocean.
During the thermosensitive period of incubation, split and shaded clutches were both 1.00 ˚C cooler than control nests. Clutch splitting (mean: 45 eggs) reduced nest temperatures by reducing metabolic heating during incubation compared to controls (mean: 92 eggs). Modelled primary sex ratios differed between nest treatments, with 1.50 % (± 6 % S.E.) females produced in shaded nests, 45.00 % (± 7 % S.E.) females in split nests and 69.00 % (± 6% S.E.) females in controls. Neither treatment affected hatchling size, success, mass or vigour. When clutch splitting was repeated two years later, hatch success was higher in split clutches compared to controls.
Synthesis and Applications: Clutch splitting and clutch shading successfully altered the thermal profile of incubating turtle nests. When there is sufficient knowledge to better understand the effects of intervention on fundamental population demographics, they will be useful for reducing incubation temperatures in sea turtle nests, potentially increasing nest survival and male hatchling production. The effect of clutch splitting in reducing nest temperature was lower relative to clutch shading, but requires significantly less funding, materials and specialist skill, key factors for management of turtle rookeries that are often in remote, resource‐limited areas.Worldwide Fund for NatureWAVE Foundation of Newport Aquariu
Genetic diversity of Brazilian isolates of feline immunodeficiency virus
We isolated Feline immunodeficiency virus (FIV) from three adult domestic cats, originating from two open shelters in Brazil. Viruses were isolated from PBMC following co-cultivation with the feline T-lymphoblastoid cell line MYA-1. All amplified env gene products were cloned directly into pGL8MYA. The nucleic acid sequences of seven clones were determined and then compared with those of previously described isolates. The sequences of all of the Brazilian virus clones were distinct and phylogenetic analysis revealed that all belong to subtype B. Three variants isolated from one cat and two variants were isolated from each of the two other cats, indicating that intrahost diversity has the potential to pose problems for the treatment and diagnosis of FIV infection
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