741 research outputs found

    Normal spatial learning and improved spatial working memory in mice (mus musculus) lacking dopamine d4 receptors

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    Dopamine terminals in the hippocampus and prefrontal cortex modulate cognitive processes such as spatial learning and working memory. Because dopamine D4 receptors are expressed in these brain areas we have analyzed mutant mice lacking this receptor subtype (Drd4-/-). Wild-type and Drd4-/- mice were challenged in two spatial learning paradigms: the Morris water maze and an alternation T-maze. Drd4-/- mice showed normal place learning ability to find a hidden platform based on spatial extra-maze cues. In addition, Drd4-/- mice were able to find a new platform location with the same learning plasticity as wild type-mice. Spatial working memory assessed on a T maze showed that Drd4-/- mice were more efficient than wild-type mice in acquiring the maximum plateau of correct alternation scores. These results provide further evidence that the functional consequence of lacking D4 receptors is more evident in behaviors dependent on the integrity of the prefrontal cortex.Fil: Falzone, Tomas Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Avale, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Gelman, Diego Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    External localization system for mobile robotics

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    We present a fast and precise vision-based software intended for multiple robot localization. The core component of the proposed localization system is an efficient method for black and white circular pattern detection. The method is robust to variable lighting conditions, achieves sub-pixel precision, and its computational complexity is independent of the processed image size. With off-the-shelf computational equipment and low-cost camera, its core algorithm is able to process hundreds of images per second while tracking hundreds of objects with millimeter precision. We propose a mathematical model of the method that allows to calculate its precision, area of coverage, and processing speed from the camera’s intrinsic parameters and hardware’s processing capacity. The correctness of the presented model and performance of the algorithm in real-world conditions are verified in several experiments. Apart from the method description, we also publish its source code; so, it can be used as an enabling technology for various mobile robotics problems

    Photophysical and photodynamic analysis of different formulations of riboflavin

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    Background: Riboflavin (Rb) has been used in the ophthalmological procedure known as corneal cross-linking (CXL). Pathologies requiring this treatment include keratoconus, corneal ectasia, and infectious keratitis. Rb is instilled via different molecules that are transported into the tissues. However, each vehicle imparts different properties that alter the photodynamic behavior of Rb, leading to variable concentrations of free radicals within the medium. The objective of this study was to measure the concentrations of free radicals produced by commonly used Rb formulations. To determine the free radical production level of each formulation, L-tryptophan (L-Tryp) was used as a model substrate because it can be efficiently photo-oxidized. Methods: We investigated the photodegradation of L-Tryp and its kinetics upon light exposure. The spectra were recorded using a Shimadzu UV-1800 PC spectrophotometer and a Cary Eclipse fluorescence spectrophotometer. A high-power solid-state LED light source was used for irradiation. L-Tryp degradation was performed using a 9-W LED lamp, and steady-state photolysis was conducted in quartz cells. The observed rate constants for L-Tryp degradation were determined by analyzing the changes in absorbance and fluorescence intensity. Data analysis was performed using Origin software. Results: We examined the characteristics of the photophysical and photodynamic action of the carriers in different commercially available Rb formulations. These included a) Rb with dextran, b) Rb without dextran, c) VibeX Rapid® (hydroxypropylmethylcellulose as a vehicle), d) Trans-Epithelial Kit (I) (sodium chloride as a vehicle), and e) Trans-Epithelial Kit (II) (benzalkonium chloride as a vehicle), using L-Tryp as a model substrate, and focusing on absorption and emission spectra. VibeX Rapid® exhibited the highest photo-degradation constant. The study affirmed the stability of Rb formulations for CXL and highlighted the efficacy of VibeX Rapid® in L-Tryp photo-oxidation and this rationalizes its current use as a CXL agent. Conclusions: We demonstrated that formulations for transport of Rb are of crucial importance in CXL applications. Rb in the VibeX Rapid® formulation is more effective in generating photo-degradation, and this reflects its superior performance in CXL. Future experiments should be designed and conducted to quantitatively differentiate the production of free radicals. Studies involving human participants could shed light on the clinical efficacy and safety of the available Rb formulations

    WhyCon: an efficient, marker-based localization system

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    We present an open-source marker-based localization system intended as a low-cost easy-to-deploy solution for aerial and swarm robotics. The main advantage of the presented method is its high computational efficiency, which allows its deployment on small robots with limited computational resources. Even on low-end computers, the core component of the system can detect and estimate 3D positions of hundreds of black and white markers at the maximum frame-rate of standard cameras. The method is robust to changing lighting conditions and achieves accuracy in the order of millimeters to centimeters. Due to its reliability, simplicity of use and availability as an open-source ROS module (http://purl.org/robotics/whycon), the system is now used in a number of aerial robotics projects where fast and precise relative localization is required

    Image features and seasons revisited

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    We present an evaluation of standard image features in the context of long-term visual teach-and-repeat mobile robot navigation, where the environment exhibits significant changes in appearance caused by seasonal weather variations and daily illumination changes. We argue that in the given long-term scenario, the viewpoint, scale and rotation invariance of the standard feature extractors is less important than their robustness to the mid- and long-term environment appearance changes. Therefore, we focus our evaluation on the robustness of image registration to variable lighting and naturally-occurring seasonal changes. We evaluate the image feature extractors on three datasets collected by mobile robots in two different outdoor environments over the course of one year. Based on this analysis, we propose a novel feature descriptor based on a combination of evolutionary algorithms and Binary Robust Independent Elementary Features, which we call GRIEF (Generated BRIEF). In terms of robustness to seasonal changes, the GRIEF feature descriptor outperforms the other ones while being computationally more efficient

    Cytokine responses during chronic denervation

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    BACKGROUND: The aim of the present study was to examine inflammatory responses during Wallerian degeneration in rat peripheral nerve when the regrowth of axons was prevented by suturing. METHODS: Transected rat sciatic nerve was sutured and ligated to prevent reinnervation. The samples were collected from the left sciatic nerve distally and proximally from the point of transection. The endoneurium was separated from the surrounding epi- and perineurium to examine the expression of cytokines in both of these compartments. Macrophage invasion into endoneurium was investigated and Schwann cell proliferation was followed as well as the expression of cytokines IL-1β, IL-10, IFN-γ and TNF-α mRNA. The samples were collected from 1 day up to 5 weeks after the primary operation. RESULTS: At days 1 to 3 after injury in the epi-/perineurium of the proximal and distal stump, a marked expression of the pro-inflammatory cytokines TNF-α and IL-1β and of the anti-inflammatory cytokine IL-10 was observed. Concurrently, numerous macrophages started to gather into the epineurium of both proximal and distal stumps. At day 7 the number of macrophages decreased in the perineurium and increased markedly in the endoneurium of both stumps. At this time point marked expression of TNF-α and IFN-γ mRNA was observed in the endo- and epi-/perineurium of the proximal stump. At day 14 a marked increase in the expression of IL-1β could be noted in the proximal stump epi-/perineurium and in the distal stump endoneurium. At that time point many macrophages were observed in the longitudinally sectioned epineurium of the proximal 2 area as well as in the cross-section slides from the distal stump. At day 35 TNF-α, IL-1β and IL-10 mRNA appeared abundantly in the proximal epi-/perineurium together with macrophages. CONCLUSION: The present studies show that even during chronic denervation there is a cyclic expression pattern for the studied cytokines. Contrary to the previous findings on reinnervating nerves the studied cytokines show increased expression up to 35 days. The high expressions of pro-inflammatory and anti-inflammatory cytokines in the proximal epi-/perineurial area at day 35 may be involved in the formation of fibrosis due to irreversible nerve injury and thus may have relevance to the formation of traumatic neuroma

    Protein composition of the occlusion bodies of Epinotia aporema granulovirus

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    Within family Baculoviridae, members of the Betabaculovirus genus are employed as bio-control agents against lepidopteran pests, either alone or in combination with selected members of the Alphabaculovirus genus. Epinotia aporema granulovirus (EpapGV) is a fast killing betabaculovirus that infects the bean shoot borer (E. aporema) and is a promising bio-pesticide. Because occlusion bodies (OBs) play a key role in baculovirus horizontal transmission, we investigated the composition of EpapGV OBs. Using mass spectrometry-based proteomics we could identify 56 proteins that are included in the OBs during the final stages of larval infection. Our data provides experimental validation of several annotated hypothetical coding sequences. Proteogenomic mapping against genomic sequence detected a previously unannotated ac110-like core gene and a putative translation fusion product of ORFs epap48 and epap49. Comparative studies of the proteomes available for the family Baculoviridae highlight the conservation of core gene products as parts of the occluded virion. Two proteins specific for betabaculoviruses (Epap48 and Epap95) are incorporated into OBs. Moreover, quantification based on emPAI values showed that Epap95 is one of the most abundant components of EpapGV OBs.Fil: Masson, Tomas. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Fabre, Maria Laura. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Ferrelli, Maria Leticia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Pidre, Matias Luis. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: Romanowski, Victor. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; Argentin

    Predicting peek readiness-to-train of soccer players using long short-term memory recurrent neural networks

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    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We are witnessing the emergence of a myriad of hardware and software systems that quantifies sport and physical activities. These are frequently touted as game changers and important for future sport developments. The vast amount of generated data is often visualized in graphs and dashboards, for use by coaches and other sports professionals to make decisions on training and match strategies. Modern machine-learning methods has the potential to further fuel this process by deriving useful insights that are not easily observable in the raw data streams. This paper tackles the problem of deriving peaks in soccer players' ability to perform from subjective self-reported wellness data collected using the PMSys system. For this, we train a long short-term memory recurrent neural network model using data from two professional Norwegian soccer teams. We show that our model can predict performance peaks in most scenarios with a precision and recall of at least 90%. Equipped with such insight, coaches and trainers can better plan individual and team training sessions, and perhaps avoid over training and injuries
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