819 resultados para Visual surveillance, Human activity recognition, Video annotation


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Ergonomic design of products demands accurate human dimensions-anthropometric data. Manual measurement over live subjects, has several limitations like long time, required presence of subjects for every new measurement, physical contact etc. Hence the data currently available is limited and anthropometric data related to facial features is difficult to obtain. In this paper, we discuss a methodology to automatically detect facial features and landmarks from scanned human head models. Segmentation of face into meaningful patches corresponding to facial features is achieved by Watershed algorithms and Mathematical Morphology tools. Many Important physiognomical landmarks are identified heuristically.

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Ligand-induced stabilization of G-quadruplex structures formed by the human telomeric DNA is an active area of research. The compounds which stabilize the G-quadruplexes often lead to telomerase inhibition. Herein we present the results of interaction of new monomeric and dimeric ligands having 1,3-phenylene-bis(piperazinyl benzimidazole) unit with G-quadruplex DNA (G4DNA) formed by human telomeric repeat d(G(3)T(2)A)(3)G(3)]. These ligands efficiently stabilize the preformed G4DNA in the presence of 100 mM monovalent alkali metal ions. Also, the G4DNA formed in the presence of low concentrations of ligands in 100 mM K+ adopts a highly stable parallel-stranded conformation. The G-quadruplexes formed in the presence of the dimeric compound are more stable than that induced by the corresponding monomeric counterpart. The dimeric ligands having oligo-oxyethylene spacers provide much higher stability to the preformed G4DNA and also exert significantly higher telomerase inhibition activity. Computational aspects have also been discussed.

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The study of anticancer agents that act via stabilization of telomeric G-quadruplex DNA (G4DNA) is important because such agents often inhibit telomerase activity. Several types of G4DNA binding ligands are known. In these studies, the target structures often involve a single G4 DNA unit formed by short DNA telomeric sequences. However, the 3'-terminal single-stranded human telomeric DNA can form higher-order structures by clustering consecutive quadruplex units (dimers or nmers). Herein, we present new synthetic gemini (twin) bisbenzimidazole ligands, in which the oligo-oxyethylene spacers join the two bisbenzimidazole units for the recognition of both monomeric and dimeric G4DNA, derived from d(T2AG3)4 and d(T2AG3) 8 human telomeric DNA, respectively. The spacer between the two bisbenzimidazoles in the geminis plays a critical role in the G4DNA stability. We report here (i) synthesis of new effective gemini anticancer agents that are selectively more toxic towards the cancer cells than the corresponding normal cells; (ii) formation and characterization of G4DNA dimers in solution as well as computational construction of the dimeric G4DNA structures. The gemini ligands direct the folding of the single-stranded DNA into an unusually stable parallel-stranded G4DNA when it was formed in presence of the ligands in KCl solution and the gemini ligands show spacer length dependent potent telomerase inhibition properties.

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A series of macrobicyclic dizinc(II) complexes Zn2L1-2B](ClO4)(4) (1-6) have been synthesized and characterized (L1-2 are polyaza macrobicyclic binucleating ligands, and B is the N,N-donor heterocyclic base (viz. 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)). The DNA and protein binding, DNA hydrolysis and anticancer activity of these complexes were investigated. The interactions of complexes 1-6 with calf thymus DNA were studied by spectroscopic techniques, including absorption, fluorescence and CD spectroscopy. The DNA binding constant values of the complexes were found to range from 2.80 x 10(5) to 5.25 x 10(5) M-1, and the binding affinities are in the following order: 3 > 6 > 2 > 5 > 1 > 4. All the dizinc(II) complexes 1-6 are found to effectively promote the hydrolytic cleavage of plasmid pBR322 DNA under anaerobic and aerobic conditions. Kinetic data for DNA hydrolysis promoted by 3 and 6 under physiological conditions give observed rate constants (k(obs)) of 5.56 +/- 0.1 and 5.12 +/- 0.2 h(-1), respectively, showing a 10(7)-fold rate acceleration over the uncatalyzed reaction of dsDNA. Remarkably, the macrobicyclic dizinc(II) complexes 1-6 bind and cleave bovine serum albumin (BSA), and effectively promote the caspase-3 and caspase-9 dependent deaths of HeLa and BeWo cancer cells. The cytotoxicity of the complexes was further confirmed by lactate dehydrogenase enzyme levels in cancer cell lysate and content media.

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Urea-based molecular constructs are shown for the first time to be nonlinear optically (NLO) active in solution. We demonstrate self-assembly triggered large amplification and specific anion recognition driven attenuation of the NLO activity. This orthogonal modulation along with an excellent nonlinearity-transparency trade-off makes them attractive NLO probes for studies related to weak self-assembly and anion transportation by second harmonic microscopy.

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Due to limited available therapeutic options, developing new lead compounds against hepatitis C virus is an urgent need. Human La protein stimulates hepatitis C virus translation through interaction with the hepatitis C viral RNA. A cyclic peptide mimicking the beta-turn of the human La protein that interacts with the viral RNA was synthesized. It inhibits hepatitis C viral RNA translation significantly better than the corresponding linear peptide at longer post-treatment times. The cyclic peptide also inhibited replication as measured by replicon RNA levels using real time RT-PCR. The cyclic peptide emerges as a promising lead compound against hepatitis C.

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Germline mutations in RECQL4 and p53 lead to cancer predisposition syndromes, Rothmund-Thomson syndrome (RTS) and Li-Fraumeni syndrome (LFS), respectively. RECQL4 is essential for the transport of p53 to the mitochondria under unstressed conditions. Here, we show that both RECQL4 and p53 interact with mitochondrial polymerase (Pol gamma A/B2) and regulate its binding to the mitochondrial DNA (mtDNA) control region (D-loop). Both RECQL4 and p53 bind to the exonuclease and polymerase domains of Pol gamma A. Kinetic constants for interactions between Pol gamma A-RECQL4, Pol gamma A-p53 and Pol gamma B-p53 indicate that RECQL4 and p53 are accessory factors for Pol gamma A-Pol gamma B and Pol gamma A-DNA interactions. RECQL4 enhances the binding of Pol gamma A to DNA, thereby potentiating the exonuclease and polymerization activities of Pol gamma A/B2. To investigate whether lack of RECQL4 and p53 results in increased mitochondrial genome instability, resequencing of the entire mitochondrial genome was undertaken from multiple RTS and LFS patient fibroblasts. We found multiple somatic mutations and polymorphisms in both RTS and LFS patient cells. A significant number of mutations and polymorphisms were common between RTS and LFS patients. These changes are associated with either aging and/or cancer, thereby indicating that the phenotypes associated with these syndromes may be due to deregulation of mitochondrial genome stability caused by the lack of RECQL4 and p53. Summary: The biochemical mechanisms by which RECQL4 and p53 affect mtDNA replication have been elucidated. Resequencing of RTS and LFS patients' mitochondrial genome reveals common mutations indicating similar mechanisms of regulation by RECQL4 and p53.

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Wave propagation around various geometric expansions, structures, and obstacles in cardiac tissue may result in the formation of unidirectional block of wave propagation and the onset of reentrant arrhythmias in the heart. Therefore, we investigated the conditions under which reentrant spiral waves can be generated by high-frequency stimulation at sharp-edged obstacles in the ten Tusscher-Noble-Noble-Panfilov (TNNP) ionic model for human cardiac tissue. We show that, in a large range of parameters that account for the conductance of major inward and outward ionic currents of the model fast inward Na+ current (INa), L-type slow inward Ca2+ current (I-CaL), slow delayed-rectifier current (I-Ks), rapid delayed-rectifier current (I-Kr), inward rectifier K+ current (I-K1)], the critical period necessary for spiral formation is close to the period of a spiral wave rotating in the same tissue. We also show that there is a minimal size of the obstacle for which formation of spirals is possible; this size is similar to 2.5 cm and decreases with a decrease in the excitability of cardiac tissue. We show that other factors, such as the obstacle thickness and direction of wave propagation in relation to the obstacle, are of secondary importance and affect the conditions for spiral wave initiation only slightly. We also perform studies for obstacle shapes derived from experimental measurements of infarction scars and show that the formation of spiral waves there is facilitated by tissue remodeling around it. Overall, we demonstrate that the formation of reentrant sources around inexcitable obstacles is a potential mechanism for the onset of cardiac arrhythmias in the presence of a fast heart rate.

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Shape and texture are both important properties of visual objects, but texture is relatively less understood. Here, we characterized neuronal responses to discrete textures in monkey inferotemporal (IT) cortex and asked whether they can explain classic findings in human texture perception. We focused on three classic findings on texture discrimination: 1) it can be easy or hard depending on the constituent elements; 2) it can have asymmetries, and 3) it is reduced for textures with randomly oriented elements. We recorded neuronal activity from monkey inferotemporal (IT) cortex and measured texture perception in humans for a variety of textures. Our main findings are as follows: 1) IT neurons show congruent selectivity for textures across array size; 2) textures that were easy for humans to discriminate also elicited distinct patterns of neuronal activity in monkey IT; 3) texture pairs with asymmetries in humans also exhibited asymmetric variation in firing rate across monkey IT; and 4) neuronal responses to randomly oriented textures were explained by an average of responses to homogeneous textures, which rendered them less discriminable. The reduction in discriminability of monkey IT neurons predicted the reduced discriminability in humans during texture discrimination. Taken together, our results suggest that texture perception in humans is likely based on neuronal representations similar to those in monkey IT.

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Action recognition plays an important role in various applications, including smart homes and personal assistive robotics. In this paper, we propose an algorithm for recognizing human actions using motion capture action data. Motion capture data provides accurate three dimensional positions of joints which constitute the human skeleton. We model the movement of the skeletal joints temporally in order to classify the action. The skeleton in each frame of an action sequence is represented as a 129 dimensional vector, of which each component is a 31) angle made by each joint with a fixed point on the skeleton. Finally, the video is represented as a histogram over a codebook obtained from all action sequences. Along with this, the temporal variance of the skeletal joints is used as additional feature. The actions are classified using Meta-Cognitive Radial Basis Function Network (McRBFN) and its Projection Based Learning (PBL) algorithm. We achieve over 97% recognition accuracy on the widely used Berkeley Multimodal Human Action Database (MHAD).

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Poly(ADP-ribose) polymerase (PARP) is a critical nuclear enzyme which safeguards genome stability from genotoxic insults and helps in DNA repair. Inhibition of PARP results in sustained DNA damage in cancer cells. PARP inhibitors are known to play an important role in chemotherapy as single agents in many DNA repair pathway deficient tumor cells or in combination with several other chemotherapeutic agents. In the present study, we synthesize and characterize novel pyridazine derivatives, and evaluate their potential for use as PARP inhibitors. Results show that pyridazine derivatives inhibited the PARP1 enzymatic activity at the nanomolar range and showed anti-proliferative activity in leukemic cells. Interestingly, human leukemic cell line, Nalm6, in which PARP1 and PARP2 expression as well as intrinsic PARP activity are high, showed significant sensitivity for the novel inhibitors compared to other leukemic cells. Among the inhibitors, P10 showed maximum inhibition of intrinsic PARP activity and inhibited cell proliferation in Nalm6 cells. Besides P10 also showed maximum inhibition against purified PARP1 protein, which was comparable to olaparib in our assays. Newly synthesized compounds also showed remarkable DNA trapping ability, which is a signature feature of many PARP inhibitors. Importantly, P10 also induced late S and G2/M arrest in Nalm6 cells, indicating accumulation of DNA damage. Therefore, we identify P10 as a potential PARP inhibitor, which can be developed as a chemotherapeutic agent.

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Mammalian cells subjected to conditions of spaceflight and the microgravity environment ofspace; manifest a number of alterations in structure and function. Among the most notable changes incells flown on the Space Shuttle are reduced growth activation and decline in growth rate in the totalpopulation. Other changes include chromosomal aberrations, inhibited locomotion, alteredcytokine production, changes in PKC distribution, and increased apoptos.

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In the life of the Law School, focus on the “visual” can operate at three different levels: learning, teaching, and examining (legal concepts). My main interest in this paper is to explore the latter level, “examining”, broadly considered so as to encompass evaluation in general. Furthermore, that interest is pinned down here to the area of constitutional rights and human rights in general, even though the conclusions reached can (and should) likely be extrapolated to other areas of the law... In effect, the first logical step regarding the relevance of the visual approach has to do with using it yourself when you study —assuming that you came to the conclusion that you are a “visual learner”. As you know, VARK theorists propose a quadripartite classification of learners. The acronym VARK stands for Visual, Aural, Read/write, and Kinesthetic sensory modalities that are used for learning information. This model was designed in the late 80s by Neil Fleming and it has received some acceptance and a lot of attention...

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Resumen: De acuerdo con el autor, la capacidad del alma de conocerse a sí misma está en la raíz del problema de la persona. Más aún, el entendimiento deber ser interpretado antológicamente como una actividad del alma. Se lleva a cabo un análisis del concepto de persona en algunos filósofos medievales y modernos. También hay referencias a pensadores contemporáneos. El autor sostiene que la noción que Spaemann introduce, considerando la intencionalidad como meramente un sentimiento o negatividad, es insuficiente. El mencionado sentimiento subjetivo es idéntico al concepto de ‘intuición experienciante’ en la fenomenología; pero es insuficiente para permitirnos comprender la esencia de la persona como una entidad espiritual. El autor afirma que cada ser humano debería ser reconocido, no sólo como una creatura racional, sino también como persona, en especial cuando nos referimos a este ser humano o a esta alma. Agrega que las consecuencias prácticas de esta perspectiva son de gran importancia.