1,181 research outputs found

    Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy

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    The purpose of this study was to investigate refraction at birth and during the first year of life in a large cohort of babies born in a single center in Northern Italy. We also aimed to analyze refractive errors in relation to the gestational age at birth. An observational ophthalmological assessment was performed within 24 h of birth on 12,427 newborns. Refraction was examined using streak retinoscopy after the administration of tropicamide (1%). Values in the range of between +0.50 ≤ D ≤ +4.00 were defined as physiological refraction at birth. Newborns with refraction values outside of the physiological range were followed up during the first year of life. Comparative analyses were conducted in a subgroup of babies with known gestational ages. The following distribution of refraction at birth was recorded: 88.03% of the babies had physiological refraction, 5.03% had moderate hyperopia, 2.14% had severe hyperopia, 3.4%, had emmetropia, 0.45%, had myopia, 0.94% had astigmatism, and 0.01% had anisometropia. By the end of the first year of life, we observed reductions in hyperopia and astigmatism, and stabilization of myopia. Preterm babies had a four-fold higher risk of congenital myopia and a three-fold higher risk of congenital emmetropia as compared to term babies. Refraction profiles obtained at birth changed during the first year of life, leading to a normalization of the refraction values. Gestational age at birth affected the incidence of refractive errors and amblyopia

    the effect of laurus nobilis on the blood and lenses antioxidant activity in rabbit under fat enriched diet

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    Fat-enriched diet is strongly associated with cataract development. Laurus nobilis shows antioxidant activity. Herein we evaluated the effect of Laurus nobilis oral administration on the blood and lenses antioxidant activity in rabbits under fat-enriched diet. Sixty rabbits divided into 4 groups were used. One group represented the control (N-CTR). The second group (P-CTR) fed a diet supplemented with 2.5 % of pig fat; the third group (EXP1) received a diet supplemented with 2.5 % of pig fat and 1 g/kg of dried-bay leaves; the fourth group (EXP2) was treated with dried-bay leaves at the rate of 1 g/kg of feed. At baseline and at the end of the study (56 days) the following blood parameters were determined: thiobarbituric acid reactive substances (TBARS), reactive oxygen metabolites (ROMs), total phenols, superoxide dismutase (SOD), oxygen radical absorbance capacity (ORACpca), ferric ion reducing antioxidant power (FRAP), retinol and alfa-tocopherol. At the end of the follow-up, the eyes were enucleated and the antioxidant profile, such as total antioxidant activity (TAC), TBARS, retinol and alfa-tocopherol of lenses was evaluated. Plasma ROMs and TBARS levels were statistically lower in the groups receiving bay leaves integration. A significant increase of plasma retinol, FRAP and ORACpca levels was found in EXP1 and EXP2 groups, whereas plasma alfa-tocopherol resulted statistically higher only in EXP2 group. Bay leaves supplementation enhanced TAC, retinol and alfa-tocopherol in rabbit lens, particularly in EXP2 group; whereas lenses TBARS levels significantly decreased in both treated groups. These findings demonstrate that Laurus nobilis oral administration exerts a protective effect on the risk of cataract development in rabbits under fat-enriched diet

    The effect of Laurus nobilis on the blood and lenses antioxidant activity in rabbit under fat-enriched diet

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    Fat-enriched diet is strongly associated with cataract development. Laurus nobilis shows antioxidant activity. Herein we evaluated the effect of Laurus nobilis oral administration on the blood and lenses antioxidant activity in rabbits under fat-enriched diet. Sixty rabbits divided into 4 groups were used. One group represented the control (N-CTR). The second group (P-CTR) fed a diet supplemented with 2.5 % of pig fat; the third group (EXP1) received a diet supplemented with 2.5 % of pig fat and 1 g/kg of dried-bay leaves; the fourth group (EXP2) was treated with dried-bay leaves at the rate of 1 g/kg of feed. At baseline and at the end of the study (56 days) the following blood parameters were determined: thiobarbituric acid reactive substances (TBARS), reactive oxygen metabolites (ROMs), total phenols, superoxide dismutase (SOD), oxygen radical absorbance capacity (ORACpca), ferric ion reducing antioxidant power (FRAP), retinol and alfa-tocopherol. At the end of the follow-up, the eyes were enucleated and the antioxidant profile, such as total antioxidant activity (TAC), TBARS, retinol and alfa-tocopherol of lenses was evaluated. Plasma ROMs and TBARS levels were statistically lower in the groups receiving bay leaves integration. A significant increase of plasma retinol, FRAP and ORACpca levels was found in EXP1 and EXP2 groups, whereas plasma alfa-tocopherol resulted statistically higher only in EXP2 group. Bay leaves supplementation enhanced TAC, retinol and alfa-tocopherol in rabbit lens, particularly in EXP2 group; whereas lenses TBARS levels significantly decreased in both treated groups. These findings demonstrate that Laurus nobilis oral administration exerts a protective effect on the risk of cataract development in rabbits under fat-enriched diet

    Assessing the Usability of a Visual Tool for the definition of E-learning Processes

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    In this paper, we present a usability study aiming at assessing a visual language-based tool for developing adaptive e-learning processes. The tool implements the adaptive self-consistent learning object SET (ASCLO-S) visual language, a special case of flow diagrams, to be used by instructional designers to define classes of learners through stereotypes and to specify the more suited adaptive learning process for each class of learners. The usability study is based on the combined use of two techniques: a questionnaire-based survey and an empirical analysis. The survey has been used to achieve feedbacks from the subjects' point of view. In particular, it has been useful to capture the perceived usability of the subjects. The outcomes show that both the proposed visual notation and the system prototype are suitable for instructional designers with or without experience on the computer usage and on tools for defining e-learning processes. This result is further confirmed by the empirical analysis we carried out by analysing the correlation between the effort to develop adaptive e-learning processes and some measures suitable defined for those processes. Indeed, the empirical analysis revealed that the effort required to model e-learning processes is not influenced by the experience of the instructional designer with the use of e-learning tools, but it only depends on the size of the developed process

    Evidence for a chemically differentiated outflow in Mrk 231

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    Aims: Our goal is to study the chemical composition of the outflows of active galactic nuclei and starburst galaxies. Methods: We obtained high-resolution interferometric observations of HCN and HCO+^+ J=1→0J=1\rightarrow0 and J=2→1J=2\rightarrow1 of the ultraluminous infrared galaxy Mrk~231 with the IRAM Plateau de Bure Interferometer. We also use previously published observations of HCN and HCO+^+ J=1→0J=1\rightarrow0 and J=3→2J=3\rightarrow2, and HNC J=1→0J=1\rightarrow0 in the same source. Results: In the line wings of the HCN, HCO+^+, and HNC emission, we find that these three molecular species exhibit features at distinct velocities which differ between the species. The features are not consistent with emission lines of other molecular species. Through radiative transfer modelling of the HCN and HCO+^+ outflow emission we find an average abundance ratio X(HCN)/X(HCO+)≳1000X(\mathrm{HCN})/X(\mathrm{HCO}^+)\gtrsim1000. Assuming a clumpy outflow, modelling of the HCN and HCO+^+ emission produces strongly inconsistent outflow masses. Conclusions: Both the anti-correlated outflow features of HCN and HCO+^+ and the different outflow masses calculated from the radiative transfer models of the HCN and HCO+^+ emission suggest that the outflow is chemically differentiated. The separation between HCN and HCO+^+ could be an indicator of shock fronts present in the outflow, since the HCN/HCO+^+ ratio is expected to be elevated in shocked regions. Our result shows that studies of the chemistry in large-scale galactic outflows can be used to better understand the physical properties of these outflows and their effects on the interstellar medium (ISM) in the galaxy.Comment: 12 pages, 8 figures, accepted for publication in A&

    Effects of orexins on 17β-estradiol synthesis and P450 aromatase modulation in the testis of alpaca (Vicugna pacos).

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    The steroidogenic enzyme P450 aromatase (ARO) has a key role in the conversion of testosterone (T) into estrogens (E), expressed as 17β-estradiol. The presence and localization of this key enzyme have not been described before in the South American camelid alpaca (Vicugna pacos). In our previous studies of the expression and biological effects of orexin A (OxA) and OxB on the alpaca testis demonstrated that OxA, via its specific receptor 1 (OX1R), stimulated T synthesis. In order to extend these findings, we presently explored the presence and localization of ARO in the alpaca male gonad, and the possible correlation between ARO and the orexinergic complex. Western blotting and immunohistochemistry demonstrated the presence of ARO in tissue homogenates and its localization in the tubular and interstitial compartments of the alpaca testis, respectively. The addition of OxA to fresh testicular slices decreased the 17β-estradiol E levels. This effect was annulled by the sequential addition of the selective OX1R antagonist, SB-408124. OxB incubation did not have any effect on the biosynthesis of E. Furthermore, the OxA-mediated down-regulation of E secretion could be ascribed to ARO inhibition by exogenous OxA, as indicated by measurement of ARO activity in tissue slices incubated with OxA. Overall, our findings suggest that locally secreted OxA interacting with OX1R could indirectly inhibit ARO activity, disabling the conversion of T to E, and consequently lowering E biosynthesis and increasing the production of T in mammalian testis

    VO2 indirect maximum and fitness age of sedentary and non-sedentary

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    El objetivo es: comparar la edad cronológica con la edad fitness obtenida por medio del VO2 máximo indirecto, de un grupo de personas sedentarias y no sedentarias. Método: 253 personas fueron evaluadas respecto a masa corporal, estatura, perímetro de cintura, frecuencia cardiaca basal y un cuestionario del modelo web "Fitness Calculator". Los resultados demostraron diferencias significativas en las variables antropométricas y fisiológicas entre personas sedentarias y no sedentarias (P<,001). Las personas no sedentarias tienen un mayor VO2máx en comparación con las personas sedentarias. Las personas sedentarias indican que presentan una edad fitness que se encuentra sobre 12 años cronológicos promedio de lo esperado. Conclusión: Las personas sedentarias tienen una mayor edad fitness, esto permite establecer que su cuerpo se deteriora más rápido que los no sedentarios. El bajo VO2 máx es un potente predictor de la capacidad cardiorrespiratoria y se establece como un predictor de enfermedades cardiovascularesThe purpose was to compare chronological age with fitness age obtained through indirect VO2max in a group of sedentary and non-sedentary people. Method: 253 people were evaluated for body mass, height, waist circumference, basal heart rate and a web model questionnaire "Fitness Calculator". The results: showed significant differences in anthropometric and physiological variables between sedentary and non-sedentary people (P <.001). Non- Sedentary people have a greater higher VO2máx group compared to sedentary people. This indicates that sedentary people have a fitness age 12 years over their expected chronological average age. Conclusion: Sedentary people have a higher fitness age; therefore your body deteriorates faster than the nonsedentary people. A low level of VO2máx is a powerful predictor of cardiorespiratory capacity and of cardiovascular diseasesEl estudio fue financiado por la Escuela de Kinesiología de la Universidad Bernardo O`higgin

    effects of an antioxidant protective topical formulation on eye exposed to ultraviolet irradiation a study in rabbit animal model

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    Ultraviolet-radiation exerts a well-known role in the development of various ocular diseases and may contribute to the progress of age-related macular degeneration. Therefore, the use of compounds able to protect the eyes from UV-induced cellular damage is challenging. The aim of this study has been to test the protective effects of an antioxidant topical formulation against UV-induced damage in rabbit eyes. Twelve male rabbits were used. Animals were divided into 4 groups of 3 animals each. Control group (CG) did not receive any irradiation and/or eye drop. The other three experimental groups were treated as follows: the first group received only UVR irradiation for 30 min, without eye drop supplementation (Irradiation group, IG), the second (G30) and the third (G60) groups received UV irradiation for 30' and 60', respectively, and eye drop supplementation (riboflavin, d-α-tocopheryl polyethylene glycol, proline, glycine, lysine and leucine solution) every 15 min for three hours. In the IG group a significant increase of oxidized glutathione (GSSG) and hydrogen peroxide (H2O2) was recorded in the aqueous humor, whereas ascorbic acid levels were significantly lower when compared to control eyes. In the groups exposed to UVR rays for 30 min, and treated with the topical antioxidant formulation, the GSSG, H2O2 and ascorbic acid levels were similar to those recorded in controls, whereas in the G60 group the three markers significantly differ from control group. In the lens, a significant decrease of alpha tocopherol and total antioxidant capacity (TAC) was recorded in IG-animals as compared to control group, whereas malondialdehyde (MDA) levels were significantly higher in UV-induced eye than in control eyes. In the G30 groups the alpha tocopherol, MDA and TAC levels do not significantly differ from those recorded in controls, whereas in the G60 group these three markers significantly differ from control group. Present findings demonstrate that topical treatment with the antioxidant formulation used herein protects ocular structures from oxidative stress induced by UV exposure in in vivo animal model
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