29 research outputs found

    Bioreactivity, Guttation and Agents Influencing Surface Tension of Water Emitted by Actively Growing Indoor Mould Isolates

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    The secretion of metabolites in guttation droplets by indoor moulds is not well documented. This study demonstrates the guttation of metabolites by actively growing common indoor moulds. Old and fresh biomasses of indoor isolates of Aspergillus versicolor, Chaetomium globosum, Penicillium expansum, Trichoderma atroviride, T. trixiae, Rhizopus sp. and Stachybotrys sp. were compared. Metabolic activity indicated by viability staining and guttation of liquid droplets detected in young (6 months old) cultures consisting of dehydrated hyphae and dormant conidia. Fresh

    PALAEORUNOFF FROM LAKE LADOGA TO THE BALTIC SEA DURING THE HOLOCENE

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    The article presents the results of the palaeohydrological analysis of the river system reorganization in the North-West of Russia, the Karelian Isthmus. This study aimed at the hydrological calculation of the runoff through the Heinjoki water connection of Lake Ladoga, the Gulf of Finland and PalaeoVuoksa during different periods of the Holocene. The methods of the equation of water balance, hydraulic-morphometric dependencies and the method of geographical analogy were used in this research. The main result of the carried work is the refinement of the existing regional flow model. In particular, the role of the Heinjoki Strait and the Neva River channel in different stages of the Holocene is considered. The authors came to the conclusion that Lake Ladoga always had a runoff to the Baltic Sea. It is shown that most probably in the period of 10,200-3,500 years ago the runoff was carried out through the Heinjoki waterway. The study underlines that the isostatic factor played a significant role in the forming of the water flow. The change in the runoff direction from the Heinjoki waterway to the Neva River is mainly related to the isostatic uplift of the Karelian Isthmus and the northern part of Lake Ladoga. Quantitative parameters of the Heinjoki palaeoflow (flow rate, annual runoff, runoff layer, runoff coefficient) seem to be roughly equivalent to the modern parameters of the flow of the Neva River. The article is dedicated to our colleague, a talented geographer and teacher, PhD Oleg Borisovich Averichkin (1979-2010) who first performed the calculations of the paleorunoff of Lake LadogaThe article presents the results of the palaeohydrological analysis of the river system reorganization in the North-West of Russia, the Karelian Isthmus. This study aimed at the hydrological calculation of the runoff through the Heinjoki water connection of Lake Ladoga, the Gulf of Finland and PalaeoVuoksa during different periods of the Holocene. The methods of the equation of water balance, hydraulic-morphometric dependencies and the method of geographical analogy were used in this research. The main result of the carried work is the refinement of the existing regional flow model. In particular, the role of the Heinjoki Strait and the Neva River channel in different stages of the Holocene is considered. The authors came to the conclusion that Lake Ladoga always had a runoff to the Baltic Sea. It is shown that most probably in the period of 10,200-3,500 years ago the runoff was carried out through the Heinjoki waterway. The study underlines that the isostatic factor played a significant role in the forming of the water flow. The change in the runoff direction from the Heinjoki waterway to the Neva River is mainly related to the isostatic uplift of the Karelian Isthmus and the northern part of Lake Ladoga. Quantitative parameters of the Heinjoki palaeoflow (flow rate, annual runoff, runoff layer, runoff coefficient) seem to be roughly equivalent to the modern parameters of the flow of the Neva River. The article is dedicated to our colleague, a talented geographer and teacher, PhD Oleg Borisovich Averichkin (1979-2010) who first performed the calculations of the paleorunoff of Lake Ladog

    Problems of personnel irradiation in modern medical technologies

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    BACKGROUND: The widespread use of radiation sources in medical practice (cardio-endovascular surgery, endoscopy, traumatology, urology, neurosurgery, dentistry, and radioisotope diagnostics departments) leads to irradiation of the lens of the eye and the skin of the hands. The introduction of new recommendations by the IAEA to reduce the limit of the annual equivalent dose to the lens (20 mSv) has led to an inaccurate dose assessment based on the effective dose. AIM: To analyze approaches and assess equivalent doses of irradiation of the lens of the eye and skin of the hands of medical personnel during various diagnostic studies under the influence of X-rays and radiopharmaceuticals studies and to compare the results obtained with previously published data. MATERIALS AND METHODS: Thermo-luminescent dosimetry was used. Dose assessment was performed by cardio-endovascular surgery, endoscopy, isotope diagnostics, dentistry, and urology personnel. RESULTS: The estimated annual equivalent doses to the lens of the eye for doctors of cardio-endovascular surgery departments, in most cases, ranging 3590 mSv, 619 mSv for the average medical staff (in some cases, the doctor [225 mSv] and the nurse [180 mSv]) and 4.59 mSv for the staff of the department of radioisotope diagnostics. The annual calculated equivalent doses to the skin of the hands for cardio-endovascular surgery personnel were 17100 and 24220 mSv for the staff working with radiopharmaceuticals. It is shown that the use of an estimate of the average dose per operation by cardio-endovascular surgery doctors, as a rule, inevitably leads to an excess of the equivalent dose to the lens of the eye after a certain number of operations. CONCLUSION: When a certain number of operations are exceeded (100200), equivalent doses to the eyes lens in cardio-endovascular surgery doctors above 20 mSv per year can be formed. At current radiation levels, a lesion of the eyes lens was found in a cardio-endovascular surgery doctor. The results indicate the need for further dosimetric measurements and epidemiological studies, based on which recommendations for radiation protection of the eyes lens and the skin of the hands of medical personnel working in low-intensity, scattered, gamma X-ray radiation can be developed

    Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

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    Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen
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