447 research outputs found

    Optimization of Chaetoceros gracilis microalgae production for fish feeding using an airlift photobioreactor

    Get PDF
    An experimental procedure was carried out to maximize Chaetoceros gracilis growth. Chaetoceros gracilis, marine microalgae, is considered for feeding fisheries with no GMO (Genetically Modified Organisms) to avoid human health hazards. Furthermore, following United Nations Resolution on water, the microalgae is grown in photobioreactors due to its low water usage. To maximize the microalgae growth, an experimental design was carried out to analyze the effects of Light Intensity, CO2 supply per day, Sparger type, Photoperiod and Inlet airflow, pH and water temperature were monitored but not controlled. It was found that Light intensity and CO2 supply per day have statistical significance. Out of three possible scenarios, 1700 lux and 80 gr/day of CO2, leads to a cell density at day three of 310×104 cel/mL which represents 20% more of the density attained in day two under bag (standard) growing conditions. It was also found that water Ph has also a strong effect over cell density

    VIRTUAL DIVING IN THE UNDERWATER ARCHAEOLOGICAL SITE OF CALA MINNOLA

    Get PDF
    The paper presents the application of the technologies and methods defined in the VISAS project for the case study of the underwater archaeological site of Cala Minnola located in the island of Levanzo, in the archipelago of the Aegadian Islands (Sicily, Italy). The VISAS project (http://visas-project.eu) aims to improve the responsible and sustainable exploitation of the Underwater Cultural Heritage by means the development of new methods and technologies including an innovative virtual tour of the submerged archaeological sites. In particular, the paper describes the 3D reconstruction of the underwater archaeological site of Cala Minnola and focus on the development of the virtual scene for its visualization and exploitation. The virtual dive of the underwater archaeological site allows users to live a recreational and educational experience by receiving historical, archaeological and biological information about the submerged exhibits, the flora and fauna of the place

    Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections

    Get PDF
    SummaryObjectivesThe kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue infection were studied.DesignSerum, saliva, and urine samples were collected from 22 patients with clinical and confirmed dengue 3 virus infection during the outbreak in Havana City in 2001. They were tested by capture IgM (MAC-ELISA), IgA (AAC-ELISA), and IgE (EAC-ELISA) and IgG ELISA inhibition method (EIM) to detect specific dengue antibodies.ResultsSimilar kinetics were observed in IgM, IgA, and IgG antibodies in saliva and IgA and IgG in urine samples from secondary cases compared with kinetics in serum samples, although the values were lower. No IgG antibody was detected in saliva and urine samples in primary cases and IgM antibody was not detected in urine samples from either primary or secondary infection. All secondary cases were positive for IgG in saliva and urine samples at day 7. The kinetics of specific IgE antibodies in primary and secondary cases were different.ConclusionsThe kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infection were studied for the first time, showing its behavior and usefulness in dengue virus diagnosis. The specific IgE could play a role as a serological marker in secondary infections

    Burkholderia from fungus gardens of fungus-growing ants produce antifungals that inhibit the specialized parasite Escovopsis.

    Get PDF
    Within animal-associated microbiomes, the functional roles of specific microbial taxa are often uncharacterized. Here, we use the fungus-growing ant system, a model for microbial symbiosis, to determine the potential defensive roles of key bacterial taxa present in the ants’ fungus gardens. Fungus gardens serve as an external digestive system for the ants, with mutualistic fungi in the genus Leucoagaricus converting the plant substrate into energy for the ants. The fungus garden is host to specialized parasitic fungi in the genus Escovopsis. Here, we examine the potential role of Burkholderia spp. that occur within ant fungus gardens in inhibiting Escovopsis. We isolated members of the bacterial genera Burkholderia and Paraburkholderia from 50% of the 52 colonies sampled, indicating that members of the family Burkholderiaceae are common inhabitants in the fungus gardens of a diverse range of fungus-growing ant genera. Using antimicrobial inhibition bioassays, we found that 28 out of 32 isolates inhibited at least one Escovopsis strain with a zone of inhibition greater than 1cm. Genomic assessment of fungus garden-associated Burkholderiaceae indicated that isolates with strong inhibition all belonged to the genus Burkholderia and contained biosynthetic gene clusters that encoded the production of two antifungals: burkholdine1213 and pyrrolnitrin. Organic extracts of cultured isolates confirmed that these compounds are responsible for antifungal activities that inhibit Escovopsis but, at equivalent concentrations, not Leucoagaricus spp. Overall, these new findings, combined with previous evidence, suggest that members of the fungus garden microbiome play an important role in maintaining the health and function of fungus-growing ant colonies.National Institutes of Health/[U19 TW009872]/NIH/Estados UnidosNational Institutes of Health/[U19 AI142720]/NIH/Estados UnidosNational Institutes of Health/[T32 AI055397]/NIH/Estados UnidosNational Science Foundation/[DEB-1927155]/NSF/Estados UnidosSão Paulo Research Foundation/[2013/50954-0]/FAPESP/BrasilUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

    A Pictorial Exploration of Mammary Paget Disease: Insights and Perspectives

    Get PDF
    Mammary Paget disease (MPD) is a rare condition primarily affecting adult women, characterized by unilateral skin changes in the nipple–areolar complex (NAC) and frequently associated with underlying breast carcinoma. Histologically, MPD is identified by large intraepidermal epithelial cells (Paget cells) with distinct characteristics. Immunohistochemical profiles aid in distinguishing MPD from other skin conditions. Clinical evaluation and imaging techniques, including magnetic resonance imaging (MRI), are recommended if MPD is suspected, although definitive diagnosis always requires histological examination. This review delves into the historical context, epidemiology, pathogenesis, clinical manifestations, and diagnosis of MPD, emphasizing the need for early detection. The classification of MPD based on pathogenesis is explored, shedding light on its varied presentations. Treatment options, including mastectomy and breast-conserving surgery, are discussed with clear guidelines for different scenarios. Adjuvant therapies are considered, particularly in cases with underlying breast cancer. Prognostic factors are outlined, underlining the importance of early intervention. Looking to the future, emerging techniques, like liquid biopsy, new immunohistochemical and molecular markers, and artificial intelligence-based image analysis, hold the potential to transform MPD diagnosis and treatment. These innovations offer hope for early detection and improved patient care, though validation through large-scale clinical trials is needed

    Microevolution of Helicobacter pylori during prolonged infection of single hosts and within families

    Get PDF
    Our understanding of basic evolutionary processes in bacteria is still very limited. For example, multiple recent dating estimates are based on a universal inter-species molecular clock rate, but that rate was calibrated using estimates of geological dates that are no longer accepted. We therefore estimated the short-term rates of mutation and recombination in Helicobacter pylori by sequencing an average of 39,300 bp in 78 gene fragments from 97 isolates. These isolates included 34 pairs of sequential samples, which were sampled at intervals of 0.25 to 10.2 years. They also included single isolates from 29 individuals (average age: 45 years) from 10 families. The accumulation of sequence diversity increased with time of separation in a clock-like manner in the sequential isolates. We used Approximate Bayesian Computation to estimate the rates of mutation, recombination, mean length of recombination tracts, and average diversity in those tracts. The estimates indicate that the short-term mutation rate is 1.4×10−6 (serial isolates) to 4.5×10−6 (family isolates) per nucleotide per year and that three times as many substitutions are introduced by recombination as by mutation. The long-term mutation rate over millennia is 5–17-fold lower, partly due to the removal of non-synonymous mutations due to purifying selection. Comparisons with the recent literature show that short-term mutation rates vary dramatically in different bacterial species and can span a range of several orders of magnitude

    Asymmetric Azidation under Hydrogen Bonding Phase-Transfer Catalysis: A Combined Experimental and Computational Study

    Get PDF
    [Image: see text] Asymmetric catalytic azidation has increased in importance to access enantioenriched nitrogen containing molecules, but methods that employ inexpensive sodium azide remain scarce. This encouraged us to undertake a detailed study on the application of hydrogen bonding phase-transfer catalysis (HB-PTC) to enantioselective azidation with sodium azide. So far, this phase-transfer manifold has been applied exclusively to insoluble metal alkali fluorides for carbon–fluorine bond formation. Herein, we disclose the asymmetric ring opening of meso aziridinium electrophiles derived from β-chloroamines with sodium azide in the presence of a chiral bisurea catalyst. The structure of novel hydrogen bonded azide complexes was analyzed computationally, in the solid state by X-ray diffraction, and in solution phase by (1)H and (14)N/(15)N NMR spectroscopy. With N-isopropylated BINAM-derived bisurea, end-on binding of azide in a tripodal fashion to all three NH bonds is energetically favorable, an arrangement reminiscent of the corresponding dynamically more rigid trifurcated hydrogen-bonded fluoride complex. Computational analysis informs that the most stable transition state leading to the major enantiomer displays attack from the hydrogen-bonded end of the azide anion. All three H-bonds are retained in the transition state; however, as seen in asymmetric HB-PTC fluorination, the H-bond between the nucleophile and the monodentate urea lengthens most noticeably along the reaction coordinate. Kinetic studies corroborate with the turnover rate limiting event resulting in a chiral ion pair containing an aziridinium cation and a catalyst-bound azide anion, along with catalyst inhibition incurred by accumulation of NaCl. This study demonstrates that HB-PTC can serve as an activation mode for inorganic salts other than metal alkali fluorides for applications in asymmetric synthesis
    • …
    corecore