147 research outputs found
Asthma Prevalence Associated with Geographical Latitude and Regional Insolation in the United States of America and Australia
BACKGROUND: It has been proposed that vitamin D deficiency may be responsible for an increase in the prevalence of allergic diseases and asthma worldwide. Human ability to generate physiologically required quantities of vitamin D through sun exposure is decreasing with increasing geographical latitude. OBJECTIVES: Considering that vitamin D deficiency is usually due to lack of outdoor sun exposure, this study is designed to test the hypothesis that a higher prevalence of asthma should be expected at high relative to low geographical latitudes. METHODS: Linear regression analyses are performed on asthma prevalence in the U.S. adult population vs. geographical latitude, insolation, air temperature, and air pollution (PM(2.5)) for 97 major metropolitan/micropolitan statistical areas of the continental United States of America and on general population asthma prevalence vs. geographical latitude in eight metropolitan areas of Australia. RESULTS: A 10Ā° change in geographical latitude from southern to northern regions of the Eastern Seaboard is associated with a 2% increase in adult asthma prevalence (p<0.001). Total insolation in winter months is almost as strong as latitude in its ability to explain the observed spatial variation in the prevalence of asthma (r(2)ā=ā0.43; p<0.001). Similar results are obtained using the Australian data (r(2)ā=ā0.73; p<0.01), suggesting a consistent association between the latitude/insolation and asthma prevalence worldwide. CONCLUSIONS: The results of this study suggest that, as a known modulator of the immune response closely linked with the geographical latitude and erythemal UV irradiation, vitamin D may play an important role in the development/exacerbation of asthma
DESIGN OF FIRST ORDER DIFFERENTIATOR WITH PARALLEL ALL-PASS STRUCTURE
In this paper a new method for design of the first order differentiator is presented. The proposed differentiator consists of two parallel branches, i.e. direct path and IIR all-pass filter. The described design method allows one to obtain solution with minimum mean relative error at the desired region by controlling the ratio of phase response extremes. A small relative magnitude error, as well as a low phase error, at low frequencies is condition for good time domain behaviour. The obtained differentiator can be realized by means of only two multipliers, hence being a good choice for real time applications. The proposed solution provides a lower magnitude error than several known differentiators with similar phase error
Fractional Calculus Model of Electrical Impedance Applied to Human Skin
Fractional calculus is a mathematical approach dealing with derivatives and integrals of arbitrary and complex orders. Therefore, it adds a new dimension to understand and describe basic nature and behavior of complex systems in an improved way. Here we use the fractional calculus for modeling electrical properties of biological systems. We derived a new class of generalized models for electrical impedance and applied them to human skin by experimental data fitting. The primary model introduces new generalizations of: 1) Weyl fractional derivative operator, 2) Cole equation, and 3) Constant Phase Element (CPE). These generalizations were described by the novel equation which presented parameter (beta) related to remnant memory and corrected four essential parameters (R-0, R-infinity, alpha, tau(alpha)). We further generalized single generalized element by introducing specific partial sum of Maclaurin series determined by parameters (beta(*), gamma,delta ...). We defined individual primary model elements and their serial combination models by the appropriate equations and electrical schemes. Cole equation is a special case of our generalized class of models for beta* = gamma = delta = ... = 0. Previous bioimpedance data analyses of living systems using basic Cole and serial Cole models show significant imprecisions. Our new class of models considerably improves the quality of fitting, evaluated by mean square errors, for bioimpedance data obtained from human skin. Our models with new parameters presented in specific partial sum of Maclaurin series also extend representation, understanding and description of complex systems electrical properties in terms of remnant memory effects
UkrŔtena rezistentnost ambrozije pelenaste (Ambrosia artemisiifolia L.) na herbicide ALS inhibitore u Srbiji
Ambrozija pelenasta (Ambrosia artemisiifolia L.) predstavlja jednu od najvažnijih invazivnih korovskih vrsta u Srbiji, za cĢije suzbijanje se u vecĢini ratarskih useva najcĢesĢcĢe koriste herbicidi ALS inhibitori. U poslednjih nekoliko godina na podruÄju južne i centralne BaÄke, ovi herbicidi nisu ispoljili oÄekivanu efikasnost u suzbijanju ove korovske vrste. Cilj ispitivanja je bio da se ispita postojanje rezistentnosti ovog korova na ALS inhibitore i njena rasprostranjenost u Srbiji. U 2018. i 2019. godine, na prostoru centralne i južne BaÄke, sa 36 polja soje, suncokreta, Å”eÄerne repe i kukuruza, sakupljeno je seme populacija ambrozije pelenaste u kojima se pretpostavlja da je doÅ”lo do razvoja rezistentnosti na herbicide ALS inhibitore. Biotestovi sa ovim populacijama imali su cilj da se proceni rasprostranjenost rezistentnosti i kreiraju mape
Trends in agile innovation management
The scope and type of applied innovations, as well as the speed of innovation by companies, today show a growing trend, which requires special efforts from the companies that claim to be leaders in the market. Therefore, these companies are forced to transform their innovative management into new forms. As an especially effective way to transform innovative management into the forefront, agile innovative management has emerged. Therefore, the theoretical desktop research of the state of development of agile innovative management from a number of perspectives has been carried out, as follows: agile innovation systems (AIS) as a phenomenon; the history of the creation of AIS; application of agile methods in companies; the basic function of agile innovation; places of agile innovation in the company; key elements of agile innovation; useful recommendations for companies that develop agile innovation; the process of agile innovation; agile behavioral approach; the uncertainty of agile innovation, and the measurement of agile innovation in companies. This paper summarizes the results of this research and gives guidelines to companies how to successfully implement agile innovation management
Methodology for evaluation of entrepreneurial training
Entrepreneurship is a field of practical action by people that integrates their ability to first discover the prospective business opportunities from the environment, then select the one that by their criteria is the most promising, then accept the risk and provide the necessary conditions for its realization, and finally to persist on the sustainability of the initiated entrepreneurial venture. In order to stimulate the development of entrepreneurship, especially in the case of people who start their own entrepreneurial venture, and in order to reduce the risk of failure, it is necessary to design appropriate entrepreneurial training. As a rule, the program of entrepreneurial training includes motivational training, training for the development of creative ideas, training in the preparation of a business plan, as well as training for its successful presentation. Here, from the standpoint of its effectiveness, the following key questions are raised: is it possible and to what extent to be evaluated the delivered entrepreneurial training in terms of learned as well as the commitment to undertake their own entrepreneurial venture? In this paper, the methodology developed for this purpose is presented in a shortened scope. The basic methodology is the standard Kirkpatrick model that consists of four levels of evaluation. Due to the specificity of the phenomenon, which is evaluated on this occasion, the model is specifically adapted to the evaluation of entrepreneurial training. The methodology is based on the survey of entrepreneurial knowledge and attitudes of the participants before and after the entrepreneurial training, as well as the subsequent analysis in order to anticipate the realized entrepreneurial effects
Prednosti zajedniÄke primene tembotriona i terbutilazina posle nicanja kukuruza
ZajedniÄka primena dva ili viÅ”e herbicida razliÄitih mehanizama delovanja je Äesta praksa, Äiji ciljevi su proÅ”irenje spektra delovanja, smanjenje troÅ”kova i spreÄavanje razvoja rezistentnosti korova na odreÄene herbicide. U zavisnosti od mehanizma delovanja, interakcije izmeÄu herbicida mogu biti sinergistiÄke, antagonistiÄke ili aditivne, u skladu sa tim da li je zajedniÄki efekat na biljke vecĢi, manji ili jednak zbiru efekata herbicida kada se primenjuju sami. Istovremena primena herbicida iz grupe triketona i triazina je korisna zbog sinergistiÄke interakcije kojom se postiže efikasnije suzbijanje korova u odnosu na njihovu pojedinaÄnu primenu. SinergistiÄka interakcija u kukuruzu je najÄeÅ”Äe koriÅ”Äena kod zajedniÄke primene mezotriona (iz grupe triketona) i terbutilazina (grupa triazina), a Å”to je moguÄe postiÄi i kombinovanjem drugih predstavnika pomenutih grupa herbicida. Cilj istraživanja je bio da se utvrdi koje su moguÄnosti zajedniÄke primene tembotriona i terbutilazina, odnosno eventualne prednosti i nedostaci, u odnosu na pojedinaÄnu primenu tembotriona i standardnu kombinaciju mezotriona i terbutilazina u kukuruzu
Toxicological analysis of the risk of lead exposure in metal processing
Purpose: To evaluate toxicological risks for workers who are exposed to lead in their work environment. Methods: Since it is an important indicator of toxicological risk, a statistical analysis of lead concentration and biological lead toxicity markers in blood and urine were performed for both exposed and control groups. Both experimental groups consisted of employees from "NISSAL" JSC factory. Analytical epidemiological method in the form of a retrospective cohort study was applied, and covered the period from 2001 to 2010. The concentration of lead, Ī“-aminolevulinic acid, and coproporphyrin in biological samples were determined by spectrophotometric methods. Results: The results showed a high positive correlation between lead concentrations in blood and urine and the length of exposure of the participants (p < 0.01). Also, increase of lead concentration in the biological material significantly increased Ī“-aminolevulinic acid (p < 0.01) and slightly increased the concentration of coproporphyrin, both of which are important indicators of toxicological risk. Conclusion: The control group of employees belonged to the normal risk category, while the exposed group belonged to a moderate risk category. Correlation between the monitored parameters is statistically significant at p < 0.01 and p < 0.05. Keywords: Lead, Ī“-Aminolevulinic acid, Coproporphyrin, Chronic exposure, Toxicity, Correlatio
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