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匹配条件: “Mariyana I. Lyubenovа” ,找到相关结果约87465条。
Chemical Elements in Mulch and Litterfall of Beech Ecosystems and Their Total Turnover
Mariyana I. Lyubenovа,Violeta G. Dimitrova
Ecologia Balkanica , 2011,
Abstract: The beech communities on the territory of Bulgaria had been objects of regional, local as well as large scale national investigations aiming their classification, determination of their ecological characteristics, conservation status, habitats etc. They are included as objects of the intensive monitoring of forest ecosystems in Bulgaria also. The investigations of chemical content of the litter – fall in these forests were conducted until now. The novelty of the present research is investigation of these elements in the mulch and the ratio between the established quantities calculation. The main goal is the biological turnover special features characterization of the investigated elements which give us a chance to define the investigated ecosystems state and functioning. The indexes as litter – mulch and acropetal coefficients were used for this aim. The content of macroelements as N, Ca and K and microelements as Pb, Zn, Mn and Fe in soils, mulch and in different litter fall fractions have been calculated. The investigation was carried out on three sample plots. During the investigation was established that the soils are characterized with acid reaction, high content of Fe, N and Mn and low content of Ca and K. The concentration of Zn and Pb are high also. The calculated average store of investigated elements in litter – fall is 81.312 kg.ha1 and in the mulch 314 kg.ha1. According to the acropetal coefficient N is accumulated mainly in the acorns, K – in the annual phytomass fractions and Ca – in the perennial fractions. The leaves and the acorns fraction accumulate Mn, and cupolas Fe. The litter – mulch coefficient vary from 1,6 (Mn) to 4,2 (Pb). The tendencies of Zn and Ca turnovers acceleration are discovered, while the turnover of more investigated elements is inhibited. The litter – mulch coefficient for Zn and Ca is 0,8 and 1,4 accordingly, i.е. corresponding to the intensive type of turnovers which is not typical for the broadleaved forest communities. The determination of cause factors and the functioning of beech communities in the future have a great importance for the environment and the economy of the country.
Research of the stopping distance for different road conditions
Transport Problems : an International Scientific Journal , 2011,
Abstract: In this paper a modern method for determination of stopping distance is represented. Application of the non-contact VBOX 3i 100Hz GPS Data Logger speed and distance measurement system is represented. A description of the total stopping distance of vehicle main components - driver reaction time, vehicle reaction time and vehicle braking capability has been made. Research of the total stopping distance of a vehicle for different road conditions has been made. The results for the stopping distance can be very useful in the expert practice.
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2005,
Abstract: The selection of individuals adaptable to environment and with high fruit quality in the case of apricot-trees is the main aim presented in this paper. The study of the rich genetic resources (3600 of seedlings) created in the Regional Centre of Applied Science - Silistra, Bulgaria, allows us to enrich the genetic fund of that plant species. By primary estimation of 1217 apricot seedlings are selected apricot elites that are studied through comparative assay with reference cultivars. The next step of the selection cycle will be the official registration of the elites for commercial aim by the State Variety Committee and a forthcoming dissemination.
New Bulgarian Work on Psychology of Creativity
Mariyana D. Nyagolova
Psychological Thought , 2012,
Abstract: A new Bulgarian work on Psychology of Creativity has been published recently. This book focuses on theoretical and methodological approaches to creativity. The results from a study of students' creativity are presented. They are related to the motives for success.
Сontribution to the History of Psychology in Bulgaria (From the Liberation to 1912)
Mariyana D. Nyagolova
Psychological Thought , 2012,
Abstract: In the history of the Bulgarian science, the period from the liberation from the Ottoman rule to 1912 is remarkable for its serious boom, for a full expression of the freedom of the science in its national and personal aspect. In these times, the beginning of the scientific psychology in the country was laid. The main schools and trends that have formed the Bulgarian psychological thought are presented here: the Leipzig School of W. Wundt, the Jena Pedagogical School, and the Geneva School of E. Claparede. The discussion on the subject of psychology in the medical circles is also stated as well as the question of teaching psychology in the secondary and higher schools. An overview of the first textbooks on psychology of Bulgarian authors is given. The historical and psychological analysis focuses on the complete works of the most famous authors who worked during the studied period.
Metabolic Syndrome and Neurotrophins: Effects of Metformin and Non-Steroidal Antiinflammatory Drug Treatment
Mariyana G. Hristova
Eurasian Journal of Medicine , 2011,
Abstract: Objective: Metabolic syndrome (MS) presents with central obesity, impaired glucose metabolism, dyslipidemia and hypertension. Our aim was to examine the effect of metformin treatment either alone or in combination with non-steroidal anti-inflammatory drugs (NSAID) on plasma levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in patients with early stage MS (MS-es) and generalized MS (MS-ge).Materials and Methods: The study compared 35 female patients with MS-es (mean age of 43.39±1.54 years) and 40 patients with MS-ge (mean age of 45.69±2.18 years) to 10 age-matched controls each. Patients with MS-es were administered 850 mg metformin twice daily. The patients with MS-ge were divided into two groups of 20 patients per group. One group received metformin alone, while the other group received metformin in combination with 500 mg aspirin and 150 mg Diclac daily. Plasma NGF and BDNF levels were measured by ELISA. Statistical data analysis was performed using ANOVA.Results: Plasma NGF and BDNF levels were significantly higher in MS-es patients and lower in MS-ge patients than in controls. NGF levels were decreased in both groups after treatment with metformin. NGF levels were significantly higher in MS-ge patients on combined therapy than in those on metformin only.Conclusion: The combination of metformin and NSAID treatment is more effective than metformin alone on NGF and BDNF production as well as on metabolism-related anthropometric and laboratory features. This represents a pathogenetic therapeutic mechanism in MS due to its strong anti-inflammatory effect and improves MS-ge symptoms.
Epidemiological Study of Hepatitis A in Plovdiv Region—Bulgaria, 2005-2008  [PDF]
Mariyana Stoycheva, Nikolay Vatev, Andrey Petrov, Chavdar Venchev, Maria Atanasova
World Journal of Vaccines (WJV) , 2011, DOI: 10.4236/wjv.2011.14017
Abstract: Background: Hepatitis A is a social disease and has great importance for public health in countries with high level of incidence rate. The problem is particularly serious for Bulgaria because the morbidity rate in the country is several times higher in comparison with the other countries of the European Union. The aim of the study is to establish the contemporary epidemiological characteristics of viral hepatitis A in Bulgaria. Methods: Analysis of the incidence rate and the age distribution has been done among two groups of the population differentiated depending on their hygienic living conditions: 1st group—living in bad hygienic conditions; 2nd group—living in good hygienic conditions. A large epidemic outbreak of hepatitis A with 1004 persons of Roma origin has been described. The comprehensive method for epidemiological research and serological methods for determining the diagnosis have been used. To study the risk factors the methods of case-control and multi-factor logistic regression are used. Results: Nine times higher incidence rate has been established in the 1st group 450/100,000 in comparison with the 2nd 50/100,000. The patients from the 1st group are predominantly children aged 5 - 9 years and from the 2nd adults aged 30 - 39 years. The level of significance of the risk factors for the biggest epidemic outbreak has been established—bad personal hygiene is of the greatest importance. The risk for travellers to countries and regions with high endemicity and during epidemic outbreaks has been shown. Conclusions: There are essential differences in the epidemiology of HAV between the groups with different hygienic living conditions. That is why the analyses of the incidence rate and age distribution of hepatitis A have to be done separately for different population groups. Recommendations for providing differentiated measures for prevention and control of hepatitis A among the two groups are given.
Epidemic Outbreaks in Plovdiv Region (Bulgaria) of Vaccine-Preventable Diseases: Measles, Mumps, Hepatitis A  [PDF]
Nikolay Todorov Vatev, Mariyana Vartigova Stoycheva, Andrei Ivanov Petrov, Rayna Dimitrova Velcheva
World Journal of Vaccines (WJV) , 2012, DOI: 10.4236/wjv.2012.23023
Abstract: Aim: To analyze the reasons for epidemic outbreaks of measles, mumps and viral hepatitis A and to propose measures to prevent them in future. Materials and methods: Тhe incidence of measles, mumps and hepatitis A in Plovdiv region was studied for the period 2006-2010. An analysis of the age structure of the patients was made, while taking into account the time for routine immunization performed against measles and mumps (first and second dose). Results: In 2006-2009 single cases of measles were found occasionally, but in 2010 they were 2787 (incidence 395/100,000). Most of them (51%) were for ages 13 months-12years, 27%-0-13 months and 11%-13 to 18 years. The incidence of mumps for 2006-2010 varied widely, and has increased significantly in 2007 (130/100,000) and 2008 (169/100,000). The majority of patients (over 34%) during the epidemics were aged 13 months-12years, and over 26% of them-13-19 years. For the period 2006-2010 the incidence of hepatitis A ranged from 2.98/100, 000 (2009) to 426/100,000 (2006). Over 50% of the cases involved children aged up to 9 years. For the three diseases over 80% of patients were individuals of Roma origin. Conclusions: 1. Epidemic spread of measles in 2010 was mainly due to shortcomings in the routine immunization carried as a prevention of the disease. 2. There are two reasons for the outbreak of mumps: А) Failure to administer the second vaccine dose at 12 years in Bulgaria until 2001. B) Shortcomings in routinely performed immunization. 3. The extremely high incidence of hepatitis A in 2006 (and in the rest of the years) is due to the lack of routine immunization. 4. Essential for the outbreaks in all three diseases are the poor hygienic living conditions, the low social status and the lack of health promotion of the population at risk 5. To prevent future outbreaks of the diseases hereby in question, we suggest it is appropriate: А) To introduce compulsory immunization against hepatitis A; B) To carry out periodic catch-up vaccination campaigns against measles and mumps.
Nedialka Petkova,Mariyana Angelova,Petko Petkov
Petroleum and Coal , 2009,
Abstract: The aim of the present paper is to establish the reasons for the enhanced corrosion observed in thecrude oil atmospheric distillation unit of LUKoil Neftochim Bourgas Co. The results from theinvestigation define the measures necessary to be taken to reduce the risk of accidents and prove thenecessity for preliminary monitoring of the sulfur and naphthenic acids content in the raw materialprocessed. World experience shows that the processing of petroleum with high content of naphthenicacids results in accelerated degradation of equipment in the temperature range 200 - 400°C. Underthese conditions characteristic for the middle-distillate fractions of the atmospheric and vacuuminstallations, naphthenic acids of low molecular weight are produced which are highly active towardsmetals. To avoid unwanted consequences for the technological equipment, it is necessary to determinethe total acidity number (TAN) and naphthenic acids number (NAN), beside the routine analyses. Whenthe presence of naphthenic acids exceeds certain limits then proper combination of measures shouldbe taken to protect the petroleum processing installation against corrosion.
Assessment of causal link between psychological factors and symptom exacerbation in inflammatory bowel disease: a protocol for systematic review of prospective cohort studies
Schoultz Mariyana,Atherton Iain,Hubbard Gill,Watson Angus JM
Systematic Reviews , 2013, DOI: 10.1186/2046-4053-2-8
Abstract: Background Inflammatory bowel disease is an idiopathic chronic disease that affects around 28 million people worldwide. Symptoms are distressing and have a detrimental effect on patients’ quality of life. A possible link between exacerbation of symptoms and psychological factors has been suspected but not established. Previous reviews concerned with this link had conceptual and methodological limitations. In this paper we set out a protocol that lays the foundations for a systematic review that will address these shortcomings. The aim of this review is to provide researchers and clinicians with clarity on the role of psychological factors in inflammatory bowel disease symptom exacerbation. Method/design We will identify all original, published, peer reviewed studies relevant to the topic and published in English from inception to November 2012. The databases MEDLINE, EMBASE, CINAHL and PsychINFO will be systematically searched. The search terms will include: inflammatory bowel disease, Crohn’s disease, ulcerative colitis, psychological stress, mental stress, life stress, family stress, hassles, social stress, coping, mood disorders, anxiety and depression in sequential combinations. Studies will be screened according to predetermined inclusion and exclusion criteria by two reviewers. We will include clinical prospective cohort studies of all human participants aged 18 years or over with a diagnosis of inflammatory bowel disease. All eligible papers will be independently and critically appraised using the Critical Appraisal Skills Programme (CASP) tool by two reviewers. Two reviewers will independently extract and synthesise data from the studies using a predefined data extraction sheet. Disagreements will be resolved by discussion between reviewers and a third party will be consulted if agreement is not reached. Synthesised data will be analysed using Bradford Hill criterion for causality. If data permits, meta-analysis will be performed. Discussion This study will provide the most comprehensive review and synthesis of current evidence around the link between psychological factors and symptom exacerbation in inflammatory bowel disease. Results will inform clinicians in appropriate intervention development for this patient group that would reduce symptom exacerbation and therefore improve patients’ quality of life.

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