387 research outputs found
A novel approach to the analysis of human growth
OBJECTIVES: Several formulations have been proposed in order to model human growth from birth to maturity. They are usually based on âad hocâ heuristic assumptions. In the present contribution we adopt, as an alternative, a completely general (interdisciplinary) approach, based on the formalism of the Phenomenological Universalities (PUN). METHODS: The main PUN class investigated to date, i.e. UN, can only account for the overall growth pattern. For a realistic description it is necessary to add to it one or more âspurtsâ, as expected on biological grounds, due to the stimulation of growth and sex hormones. RESULTS: A new PUN class (UNâ+âFM) is generated and shown to be able to provide excellent agreement with standard auxological datasets. The accuracy of the fitting and reliability of the model suggest applications both at the diagnostic and therapeutic level. CONCLUSIONS: The developed formalism can be suitably related to the biological description of bone plate growth under selective hormonal stimulation on the bone epiphysis; i.e., the additional increase of stature is the âmacroscopicâ response to a well defined biological signal
Propagation of uncertainty in atmospheric parameters to hyperspectral unmixing
Atmospheric correction (AC) is important in pre-processing of airborne hyperspectral imagery. AC requires knowledge on the atmospheric state expressed by atmospheric condition parameters. Their values are affected by uncertainties that propagate to the application level. This study investigates the propagation of uncertainty from column water vapor (CWV) and aerosol optical depth (AOD) towards abundance maps obtained by means of spectral unmixing. Both Fully Constrained Least Squares (FCLS) and FCLS with Total Variation (FCLS-TV) are applied. We use five simulated datasets contaminated by various noise levels. Three datasets cover two spectral scenarios with different endmembers. A univariate and a bivariate analysis are carried out on CWV and AOD. The other two datasets are used to analyze the effect of surface albedo. The analysis identifies trends in performance degradation caused by the gradual shift in parameter values from their true value. The maximum achievable performance depends upon spectral characteristics of the datasets, noise level, and surface albedo. As expected, under noisy conditions FCLS-TV performs better than FCLS. Our research opens new perspectives for applications where estimation of reflectance is so far considered to be deterministic
Assessment of Antifungal Activity of Lactic Acid Bacteria Strains Against Bread Spoilage Fungus Aspergillus ochraceus
Lactic acid bacteria (LAB) are generally recognized as safe and can be used against fungi that contaminate various food commodities. The aim of the research was to select LAB strains with high antifungal activity for the biocontrol of Aspergillus ochraceus. The antifungal activity of eight strains of lactic acid bacteria has been evaluated by overlay assay method against the spoilage fungus, Aspergillus ochraceus isolated from white bread. The antifungal effect was assessed by co-cultivation of lactic acid bacteria strains and Aspergillus ochraceus in liquid media and mycelium growth inhibition was monitored for over 14 days. The LAB strains Lpl, LAB 43 and LAB 13 presented intense antifungal activity with large inhibition zones of fungal growth and sporulation, but smaller for Lpa and LAB 15 strains. Total inhibition of mycelia growth was induced by the strains LAB 43, LAB 13 and Lpa. The strains LAB 15 and LAB 35 had a moderate inhibition activity on the mycelia growth. The results of this study demonstrated the antifungal activity of several LAB strains by overlay assay and by co-cultivation method. Therefore, it was confirmed the inhibitory effect of the strains LAB 43 and LAB 13 against Aspergillus ochraceus. The experiment revealed that these LAB strains could be further used as biocontrol agents
Persistent median artery in the carpal tunnel: anatomy, embryology, clinical significance, and review of the literature
The median artery usually regresses after the eighth week of intrauterine life, but
in some cases it persists into adulthood. The persistent median artery (PMA) passes
through the carpal tunnel of the wrist, accompanying the median nerve.
During anatomical dissection in our department, we found two unilateral cases
of PMA originating from the ulnar artery. In both cases the PMA passed through
the carpal tunnel, reached the palm, and anastomosed with the ulnar artery,
forming a medio-ulnar type of superficial palmar arch. In addition, in both cases
we observed a high division of the median nerve before entering the carpal
tunnel. Such an artery may result in several complications such as carpal tunnel
syndrome, pronator syndrome, or compression of the anterior interosseous nerve.
Therefore, the presence of a PMA should be taken into consideration in clinical
practice. This study presents two cases of PMA along with an embryological
explanation, analysis of its clinical significance, and a review of the literature. The
review of the literature includes cases observed during surgical procedures or
anatomical dissections. Cases observed by means of imaging techniques were
not included in the study
Recovering Hydrogen Sulfide from Sulfurous Waters with PEM Fuel Cells
AbstractHydrogen sulfide is an environmental pollutant and abundant in various sulfurous waters such as Black Sea. Hydrogen sulfide is in the same time a potential energetic materials as source for hydrogen production. In this respect, designing an appropriate fuel cell with proton exchange membranes (PEMFC) for hydrogen sulfide recovering from sulfurous water is challenge. This study reports a PEMFC with Pt/Pt-Ru catalysts and membrane with perflurosulfonic ionomer. PEMFC was run at different concentrations of hydrogen sulfide in water (50-150mg/L). Even though power densities are in the range microwatts the experimental set-up shows a promising perspective for sulfurous water treatment. A short overview on the actual state of the art in hydrogen sulfide recovering and potential applications of the fuel cells is presented in introduction
Severe head injury: The place for regional centers
We are discussing the administrative aspect of solving the severe head trauma and the new modern aspects for pre and post operatory survey, using as a point of departure the case of a patient explored and sent to our department. The aim is not always to improve patient prognosis but to be more precise in depicting patient future evolution especially with patient with isolated, severe head injury who are most prone to be subjects for organ transplantation
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