5 research outputs found
Accuracy of rats in discriminating visual objects Is explained by the complexity of their perceptual strategy
Despite their growing popularity as models of visual functions, it is widely assumed that rodents deploy perceptual strategies not nearly as advanced as those of primates, when processing visual objects. Such belief is fostered by the conflicting findings about the complexity of rodent pattern vision, which appears to range from mere detection of overall object luminance to view-invariant processing of discriminant shape features. Here, we sought to clarify how refined object vision is in rodents, by measuring how well a group of rats discriminated a reference object from eleven distractors, spanning a spectrum of image-level similarity with the reference. We also presented the animals with random variations of the reference, and we processed their responses to these stimuli to obtain subject-specific models of rat perceptual choices. These models captured very well the highly variable discrimination performance observed across subjects and object conditions. In particular, they revealed how the animals that succeeded with the more challenging distractors were those that integrated the wider variety of discriminant features into their perceptual strategy. Critically, these features remained highly subject-specific and largely invariant under changes in object appearance (e.g., size variation), although they were properly reformatted (e.g., rescaled) to deal with the specific transformations the objects underwent. Overall, these findings show that rat object vision, far from being poorly developed, can be characterized as a feature-based filtering process (iterated across multiple scales, positions, etc.), similar to the one that is at work in primates and state-of-the-art machine vision systems, such as convolutional neural networks
Predictability of Lead-210 in Surface Air Based on Multivariate Analysis
Dependence of the lead-210 activity concentration in surface air on meteorological variables and teleconnection indices is investigated using multivariate analysis, which gives the Boosted Decision Trees method as the most suitable for variable analysis. A mapped functional behaviour of the lead-210 activity concentration is further obtained, and used to test predictability of lead-210 in surface air. The results show an agreement between the predicted and measured values. The temporal evolution of the measured activities is satisfactorily matched by the prediction. The largest qualitative differences are obtained for winter months.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr
Comparative pathological findings in mute swans (Cygnus olor) naturally infected with highly pathogenic Avian influenza viruses H5N1 and H5N8 in Serbia
The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 Glade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8
Predictability of Lead-210 in Surface Air Based on Multivariate Analysis
Dependence of the lead-210 activity concentration in surface air on meteorological variables and teleconnection indices is investigated using multivariate analysis, which gives the Boosted Decision Trees method as the most suitable for variable analysis. A mapped functional behaviour of the lead-210 activity concentration is further obtained, and used to test predictability of lead-210 in surface air. The results show an agreement between the predicted and measured values. The temporal evolution of the measured activities is satisfactorily matched by the prediction. The largest qualitative differences are obtained for winter months.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr
Electrophoresis, as a Method of Rational Application of Medicament of Contemporary Management in Health Care
Preclinical studies of the intake of drugs in the body by electrophoresis and systemic route (intravenous), we examined the concentrations of drugs and the efficiency of the drug application in both ways. We found high-significance concentrations of drugs in the desired tissue, with multiple smaller amounts of drugs administered by electrophoresis, and high values of Students T-test and significance for all investigated drugs p <0.001. Investigating economic costeffectiveness, this methodology of drug intake, we observed by evaluating the cost of medicines of significant material savings with drug application with ionophoresis, which is recommended both from the health and material-financial aspect as a rational modern method of drug intake in clinical practice, wherever clinical possibilities allow it