Assemblages of myxomycetes associated with three different substrates affected by forest wildfires

Background and aims – In late November and early December of 2016, forest wildfires occurred over portions of the Great Smoky Mountains National Park (USA) and more than 4 000 ha were affected. Previous studies have shown that myxomycete assemblages can be greatly impacted as a result of this type of disturbance; after which, the recovery of the forest determines the availability of substrates for new colonisation. The objective of the project reported herein was to assess the impact of wildfires on the recovery of the assemblages of myxomycetes associated with three different substrates (forest floor leaf litter, the bark of living trees, and woody twigs) in two areas with different fire intensity. Material and methods – Two study areas subjected to different fire intensity were selected and sampled 30 months after the wildfires. Myxomycetes were studied using the moist chamber culture technique as it applies to these organisms. Satellite imagery was used to determine forest recovery and similarity indices were used to compare experimental myxomycete assemblages among study areas and substrates. Historical data were used as a reference to contextualise the results. Key results – A total of 38 species of myxomycetes representing 17 different genera were recorded from the two study areas. Samples from the lower intensity burn area yielded more myxomycetes than samples from the higher intensity burn area, with values of 84% and 59%, respectively. This same pattern was also observed for the number of recorded specimens (133 and 93, respectively). The comparison of experimental assemblages with previous data suggested that ground litter assemblages were still in early stages of recovery, whereas the assemblages associated with bark and twigs had recovered much faster. Conclusion – The relatively higher intensity fire had more of an effect on myxomycetes than the relatively lower intensity fire. Myxomycete assemblages are resilient to wildfires and they recover differentially depending on the substrate they grow on.Slime Mold Project at the University of ArkansasDiscover Life in AmericaUniversidad de Costa Rica /[731-B7-721]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ingeniería::Instituto Investigaciones en Ingeniería (INII)UCR::Vicerrectoría de Docencia::Ingeniería::Facultad de Ingeniería::Escuela de Ingeniería de Biosistema

Prevalence of hepatitis B and hepatitis C in patients of chronic kidney disease

Background: Patients of CKD are highly exposed to HBV and HCV because of multiple blood transfusions and exposure to contaminated equipments. Infections by HBV and HCV are significant cause of morbidity in CKD patients by causing liver damage and membranoproliferative GN. Present study was done to observe the prevalence of HBV and HCV in patients of CKD and to compare the prevalence of these infections in patients who were on maintenance haemodialysis and who were not on maintenance hemodialysis.Methods: This study had been conducted on 140 patients. Patients were diagnosed as having CKD on basis of Cockcroft-gault equation as per KDOQI guidelines. Stage 3, 4 or 5 patients were included for the study whereas patients with stage 1 or 2 were excluded. These 140 cases were divided into 2 groups, Group I included 70 cases who were on maintenance hemodialysis and Group II included 70 patients who were not on maintenance hemodialysis. The prevalence of HBV and HCV in the two groups was observed. Diagnosis of HBV was made by detection of HBsAg (one step immunoassay) and diagnosis of HCV was made by detection of antibodies to Hepatitis C(enzyme linked immunoassay). Prevalence data of NCDC was used for comparison with general population.Results: In Group I, 15 (21%) patients were positive for HCV and 9 (12.9%) were positive for HBV which is significantly higher compared to Group II patients in which 6 (8.6%) and 2 (2.9%) were positive respectively. Overall out of 140 patients,21(15%) were positive for HCV and 11(7.9%) were positive for HBV, which is significantly higher compared to data of NCDC for general population in which prevalence of HCV and HBV is 1% and 4% respectivelyConclusions: Prevalence of HBV and HCV was significantly higher in patients of CKD than the general population, which was further higher in patients who were on maintenance hemodialysis and have received multiple blood transfusions, emphasizing the need to implement the methods to limit the spread of HBV and HCV

Fabrication and characterizations of hydrogels for cartilage repair

YesArticular cartilage is a vascular tissue with limited repair capabilities, leaving an afflicted person in extreme pain. The tissue experiences numerous forces throughout its lifetime. This study focuses on development of a novel hydrogel composed of chitosan and β-glycerophosphate for articular cartilage repair. The aim of this study was to investigate the mechanical properties and swelling behaviour of a novel hydrogel composed of chitosan and β-glycerophosphate for cartilage repair. The mechanical properties were measured for compression forces. Mach-1 mechanical testing system was used to obtain storage and loss modulus for each hydrogel sample to achieve viscoelastic properties of fabricated hydrogels. Two swelling tests were carried out to compare water retaining capabilities of the samples. The hydrogel samples were made of five different concentrations of β-glycerophosphate cross-linked with chitosan. Each sample with different β-glycerophosphate concentration underwent sinusoidal compression forces at three different frequencies -0.1Hz, 0.316Hz and 1Hz. The result of mechanical testing was obtained as storage and loss modulus. Storage modulus represents the elastic component and loss modulus represents the viscosity of the samples. The results obtained for 1Hz were of interest because the knee experiences frequency of 1Hz during walking

New insight into the effects of lead modulation on antioxidant defense mechanism and trace element concentration in rat bone

Risks of heavy metals-induced severe bone disorders generate interest to their toxicity. The present study was undertaken to monitor the biochemical and antioxidant status of bone of 30 and 80 days old male Wistar rats exposed to 5 week lead treatment. At the end of study, the rats were sacrificed, their long bone i.e. femur were excised, cleaned of soft tissue, minced and homogenized. Nucleic acid content, alkaline phosphatase, lipid peroxidation, catalase, glutathione S-transferase and superoxide dismutase were determined in bone. In both groups of treated animals lead treatment increased the production of malondialdehyde, while reducing activities of catalase, glutathione S-transferase and superoxide dismutase, indicating that it causes oxidative stress. Parallely with these effects lead significantly reduced the nucleic acid content and the activity of alkaline phosphatase, considered as biomarkers of osteoblast's function, conditions and development of bones. Moreover the concentrations of copper, zinc, iron and sodium were reduced in the excised bones. The present study indicates that the lead induced bone toxicity and its deteriorated development is the consequence of a primary oxidative stress. Our results may be helpful in understanding the modulation of biochemical parameters under lead toxicity

Evaluation of Fermentative Xylitol Production Potential of Adapted Strains of <i>Meyerozyma caribbica</i> and <i>Candida tropicalis</i> from Rice Straw Hemicellulosic Hydrolysate

Dilute acid hydrolysis of lignocellulosic biomass generates inhibitors in the hydrolysate which hamper yeast metabolism and the fermentation process. Therefore, understanding the effect of these compounds on the performance of microorganisms becomes essential to achieve improved product yields. In this study, the effect of acetic acid, furfural, and hydroxymethylfurfural was evaluated on yeast growth and fermentation efficiency. Various parameters for the pretreatment of rice straw, such as an acid catalyst, and its concentration and residence time, were optimized for the maximum liberation of sugars in the hydrolysate. Further, the yeast strains Candida tropicalis and Meyerozyma caribbica were adapted for the tolerance of inhibitors at higher concentrations. A comparative analysis was carried out using un-adapted and adapted strains of Candida tropicalis and Meyerozyma caribbica for xylitol production. The findings of this study revealed that sulfuric acid (1.25% v/v) at 121 ரC for 30 min can efficiently convert rice straw xylan to xylose, with the release of 16.07 g/L xylose in the hydrolysate. Further, the adaptation results showed an increase of 76.42% and 69.33% in xylose assimilation by C. tropicalis and M. caribbica, respectively. The xylitol production with the adapted C. tropicalis was increased by 7.54% to 28.03 g/L xylitol. However, the xylitol production with the adapted M. caribbica was increased by 8.33%, yielding 26.02 g/L xylitol in the non-detoxified hydrolysate when compared to the un-adapted strains. Repeated batch fermentation was carried out for seven batches, and xylitol was found to be efficiently produced by the yeasts during five successive batches without any significant loss in the xylitol yield. Moreover, the results suggest that M. caribbica is a promising microorganism for the transformation of rice straw-derived xylose to xylitol

Synthesis, Characterization and Evaluation of antioxidant properties of Catechin Hydrate nanoparticles

Catechin hydrate (CH), is an important phyto compound, reported to have potential therapeutic activity for prevention and treatment of various central nervous system (CNS) disorders. However, its therapeutic action is limited by their low oral bioavailability, poor stability and intestinal absorption, therefore, development of a targeted nanoparticle based carrier system which can overcome its physicochemical limitations and can enhance its biological activity is required. The objective of the present study was to formulate nanoparticle based formulation by ionic gelation method for catechin hydrate. Result and conclusion: After optimising the formulation by statistical tool, further, characterization results showed zeta average particle size of 68.76 ± 1.72 nm along with polydispersibility index of 0.174 ± 0.81 and zeta potential of -5.32 mV. Moreover, TEM analysis also confirmed its nanometric size range (range of 61. 8- 128nm) and FT – IR scan showed no bond formation between polymers and loaded extract (CH). The in vitro compound release kinetics  showed a typical linear diffusion profile  and cytotoxicity analysis done on NB41A3 cell lines  results exhibited the cell viability of 89.5 ± 0.25% in catechin loaded nanoparticles (CH NP’s) whereas, it is 82.7 ± 0.34% in CH  indicating negligible toxicity in nanoparticle based formulation. The stability testing was done for CH NP’s after 8 weeks, and results revealed minimal degradation of catechin. Lastly, the antioxidant activities estimated through DPPH (2, 2 – Diphenyl-1-picrylhydrazyl-hydrate),  Nitric oxide (NO) and Hydrogen peroxide (H2O2) scavenging assays revealed that CH NP’s have higher and prolonged antioxidant activity in comparison with CH.