The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Veronica Rodrigues - One of the best experts on this subject based on the ideXlab platform.
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Expression and function of the empty spiracles gene in Olfactory Sense organ development of Drosophila melanogaster
Development, 2010Co-Authors: Beate Hartmann, Heinrich Reichert, Veronica RodriguesAbstract:In Drosophila, the cephalic gap gene empty spiracles plays key roles in embryonic patterning of the peripheral and central nervous system. During postembryonic development, it is involved in the development of central Olfactory circuitry in the antennal lobe of the adult. However, its possible role in the postembryonic development of peripheral Olfactory Sense organs has not been investigated. Here, we show that empty spiracles acts in a subset of precursors that generate the Olfactory Sense organs of the adult antenna. All empty spiracles-expressing precursor cells co-express the proneural gene amos and the early patterning gene lozenge. Moreover, the expression of empty spiracles in these precursor cells is dependent on both amos and lozenge. Functional analysis reveals two distinct roles of empty spiracles in the development of Olfactory Sense organs. Genetic interaction studies in a lozenge-sensitized background uncover a requirement of empty spiracles in the formation of trichoid and basiconic Olfactory sensilla. MARCM-based clonal mutant analysis reveals an additional role during axonal targeting of Olfactory sensory neurons to glomeruli within the antennal lobe. Our findings on empty spiracles action in Olfactory Sense organ development complement previous studies that demonstrate its requirement in Olfactory interneurons and, taken together with studies on the murine homologs of empty spiracles, suggest that conserved molecular genetic programs might be responsible for the formation of both peripheral and central Olfactory circuitry in insects and mammals.
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patterning an epidermal field drosophilalozenge a member of the aml 1 runt family of transcription factors specifies Olfactory Sense organ type in a dose dependent manner
Developmental Biology, 1998Co-Authors: Bhagwati P Gupta, Gail V Flores, Utpal Banerjee, Veronica RodriguesAbstract:Abstract Sense organ development in the Drosophila antenna is initiated by the selection of a founder cell from an epidermal field. This cell is believed to recruit neighbours to form a cluster of cells which then divides to form a mature Sense organ. In most systems so far studied, Sense organ type appears to be specified by the identity of proneural genes involved in the selection of precursors. The regulation of proneural gene expression is, in turn, controlled by the prepatterning genes. In the antenna, the only known proneural function is that of atonal, a gene that is involved in founder cell choice in the sensilla coeloconica, and no prepatterning gene function has yet been demonstrated. In this study, we show that Lozenge, a protein which possesses a DNA binding domain similar to that of the Acute myeloid leukemia-1/Runt transcription factors, functions in a dose-dependent manner to specify the fate of the other two types of Sense organs in the antenna: the sensilla trichoidea and the sensilla basiconica. Our results suggest that Lozenge may act on the epidermal field, resulting in founder cells acquiring specific cell fates that lead to the development of an appropriate type of Sense organ.
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atonal is a proneural gene for a subset of Olfactory Sense organs in drosophila
Genes to Cells, 1997Co-Authors: Bhagwati P Gupta, Veronica RodriguesAbstract:Background: The antenna of the adult fruit fly, Drosophila melanogaster, is covered with three morphologically distinct types of Olfactory Sense organs. In addition, mechano- and hygro-sensitive receptors are also present on its surface. While much has been learnt about the development of peripheral nervous system in Drosophila, the mechanisms underlying the development of Olfactory sensilla are just beginning to be unraveled. The antennal Sense organs have several properties that make them distinct from other Sense organs. While each sensillum type is arranged in a well-defined region of the antenna, the position of an individual sensillum is not fixed. The development of these Sense organs appears to combine an initial step of cell recruitment, as in photoreceptors, followed by cell lineage mechanisms, as in the development of other external Sense organs. The earliest step in development, the selection of a sensory organ precursor, involves the interaction of proneural and neurogenic genes. The proneural gene for the antennal Sense organs has been elusive so far. Results: We show that the basic helix-loop-helix (bHLH) transcription factor encoded by atonal (ato) is a proneural gene for one morphological type of Olfactory sensilla on the antenna and for all the Olfactory sensilla on the maxillary palp. Loss of function and overexpression experiments together reveal that ato is both necessary and sufficient to specify these sensilla. Immunohistochemical experiments show that Ato expresses in a dynamic pattern in the developing antennal disc. Conclusions: Our results demonstrate that ato acts solely in the specification of antennal sensilla coeloconica. This along with our previous observation that the AS-C genes do not function in antenna allows us to suggest that other proneural genes must operate in the specification of sensilla basiconica and trichoidea. Our experiment involving overexpression of extramacrochaetae, a negative regulator of bHLH encoding genes, results in a significant reduction in the number of all three types of antennal sensilla. This suggests that the unidentified proneural gene(s) possibly encode bHLH factors.
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development of the drosophila Olfactory Sense organs utilizes cell cell interactions as well as lineage
Development, 1997Co-Authors: G V Reddy, Bhagwati P Gupta, Veronica RodriguesAbstract:We have examined the mechanisms underlying the development of the Olfactory Sense organs on the third segment of the antenna of Drosophila. Our studies suggest that a novel developmental strategy is employed. Specification of the founder or precursor cell is not governed by the genes of the achaete-scute complex. Another basic helix-loop-helix encoding gene, atonal, is essential for determination of only a subset of the sensilla types--the sensilla coeloconica. Therefore, we predict the existence of additional proneural genes for the selection of sensilla trichoidea and sensilla basiconica. The choice of a founder cell from the presumed proneural domain is regulated by Notch activity. Soon after delamination of the founder cell, two to three additional neighboring cells also take on a sensory fate and these cells together form a presensillum cluster. The selection of neighbors does not occur when endocytosis is blocked using a temperature sensitive allele of shibire, thus suggesting that cell-cell communication is required for this step. The cells of the cluster divide once before terminal differentiation which is influenced by Notch activity. The final cell number within each sensillum is controlled by programmed cell death.
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cellular events during development of the Olfactory Sense organs in drosophila melanogaster
Developmental Biology, 1995Co-Authors: Veronica RodriguesAbstract:Abstract The Olfactory sensilla on the antenna of adult Drosophila melanogaster develop during the first 36 hr after pupariation, from their anlagen in the cephalic disc. We have used tissue-specific β-galactosidase expression in the enhancer trap strain A101.IF3 and the monoclonal antibody 22C10 as sensory cell markers, as well as the lineage tracer 5-bromo-2′-deoxyuridine (BrdU), to describe this process. The development of an Olfactory sensillum begins with the selection of a "founder cell" (FC). These cells are distinct in that they possess large apically located nuclei revealed by β-galactosidase expression in A101.IF3. In the following 6 hr, a few cells neighboring the FC also start expressing β-galactosidase and together comprise a group. Cells of this group, denoted a "presensillum-cluster" (PSC), undergo at least one round of replication and give rise to all of the cells of a sensillum. A subset of the cells within each PSC and, later, all the sensory neurons are recognized by MAb22C10. The antennae of the mutant lozenge 3 ( lz 3 ) lack all basiconic and some trichoid sensilla. The mutation apparently affects early steps in sensillum development and many of the FCs fail to form. Those that are present, however, proceed to form mature Olfactory sensilla. Therefore, we conclude that the selection of an FC is the first step in Olfactory Sense organ development. Our study reveals novel aspects of sensory development in Drosophila .
Bhagwati P Gupta - One of the best experts on this subject based on the ideXlab platform.
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patterning an epidermal field drosophilalozenge a member of the aml 1 runt family of transcription factors specifies Olfactory Sense organ type in a dose dependent manner
Developmental Biology, 1998Co-Authors: Bhagwati P Gupta, Gail V Flores, Utpal Banerjee, Veronica RodriguesAbstract:Abstract Sense organ development in the Drosophila antenna is initiated by the selection of a founder cell from an epidermal field. This cell is believed to recruit neighbours to form a cluster of cells which then divides to form a mature Sense organ. In most systems so far studied, Sense organ type appears to be specified by the identity of proneural genes involved in the selection of precursors. The regulation of proneural gene expression is, in turn, controlled by the prepatterning genes. In the antenna, the only known proneural function is that of atonal, a gene that is involved in founder cell choice in the sensilla coeloconica, and no prepatterning gene function has yet been demonstrated. In this study, we show that Lozenge, a protein which possesses a DNA binding domain similar to that of the Acute myeloid leukemia-1/Runt transcription factors, functions in a dose-dependent manner to specify the fate of the other two types of Sense organs in the antenna: the sensilla trichoidea and the sensilla basiconica. Our results suggest that Lozenge may act on the epidermal field, resulting in founder cells acquiring specific cell fates that lead to the development of an appropriate type of Sense organ.
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atonal is a proneural gene for a subset of Olfactory Sense organs in drosophila
Genes to Cells, 1997Co-Authors: Bhagwati P Gupta, Veronica RodriguesAbstract:Background: The antenna of the adult fruit fly, Drosophila melanogaster, is covered with three morphologically distinct types of Olfactory Sense organs. In addition, mechano- and hygro-sensitive receptors are also present on its surface. While much has been learnt about the development of peripheral nervous system in Drosophila, the mechanisms underlying the development of Olfactory sensilla are just beginning to be unraveled. The antennal Sense organs have several properties that make them distinct from other Sense organs. While each sensillum type is arranged in a well-defined region of the antenna, the position of an individual sensillum is not fixed. The development of these Sense organs appears to combine an initial step of cell recruitment, as in photoreceptors, followed by cell lineage mechanisms, as in the development of other external Sense organs. The earliest step in development, the selection of a sensory organ precursor, involves the interaction of proneural and neurogenic genes. The proneural gene for the antennal Sense organs has been elusive so far. Results: We show that the basic helix-loop-helix (bHLH) transcription factor encoded by atonal (ato) is a proneural gene for one morphological type of Olfactory sensilla on the antenna and for all the Olfactory sensilla on the maxillary palp. Loss of function and overexpression experiments together reveal that ato is both necessary and sufficient to specify these sensilla. Immunohistochemical experiments show that Ato expresses in a dynamic pattern in the developing antennal disc. Conclusions: Our results demonstrate that ato acts solely in the specification of antennal sensilla coeloconica. This along with our previous observation that the AS-C genes do not function in antenna allows us to suggest that other proneural genes must operate in the specification of sensilla basiconica and trichoidea. Our experiment involving overexpression of extramacrochaetae, a negative regulator of bHLH encoding genes, results in a significant reduction in the number of all three types of antennal sensilla. This suggests that the unidentified proneural gene(s) possibly encode bHLH factors.
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development of the drosophila Olfactory Sense organs utilizes cell cell interactions as well as lineage
Development, 1997Co-Authors: G V Reddy, Bhagwati P Gupta, Veronica RodriguesAbstract:We have examined the mechanisms underlying the development of the Olfactory Sense organs on the third segment of the antenna of Drosophila. Our studies suggest that a novel developmental strategy is employed. Specification of the founder or precursor cell is not governed by the genes of the achaete-scute complex. Another basic helix-loop-helix encoding gene, atonal, is essential for determination of only a subset of the sensilla types--the sensilla coeloconica. Therefore, we predict the existence of additional proneural genes for the selection of sensilla trichoidea and sensilla basiconica. The choice of a founder cell from the presumed proneural domain is regulated by Notch activity. Soon after delamination of the founder cell, two to three additional neighboring cells also take on a sensory fate and these cells together form a presensillum cluster. The selection of neighbors does not occur when endocytosis is blocked using a temperature sensitive allele of shibire, thus suggesting that cell-cell communication is required for this step. The cells of the cluster divide once before terminal differentiation which is influenced by Notch activity. The final cell number within each sensillum is controlled by programmed cell death.
Touradj Ebrahimi - One of the best experts on this subject based on the ideXlab platform.
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Subject-Independent Odor Pleasantness Classification Using Brain and Peripheral Signals
IEEE Transactions on Affective Computing, 2016Co-Authors: Eleni Kroupi, Jean-marc Vesin, Touradj EbrahimiAbstract:Enhanced sensation of reality from multimedia contents can be achieved by creating realistic multimedia environments, using visual, auditory, and Olfactory information. Although the affective information from video and audio has been extensively studied, the Olfactory Sense has received less attention. A way to assess human experience from audio, video or odors, is by investigating physiological signals. In this study, 23 subjects experienced pleasant, unpleasant, and neutral odors while their electroencephalogram (EEG), and electrocardiogram (ECG) were recorded. Two independent three-class classifiers were trained and tested, using EEG or ECG features. The results reveal a significant increase in the classification performance when EEG features were used (Cohen's kappa k = 0.44 ± 0.14; p
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Functional connectivity from EEG signals during perceiving pleasant and unpleasant odors
2015 International Conference on Affective Computing and Intelligent Interaction (ACII), 2015Co-Authors: He Xu, Eleni Kroupi, Touradj EbrahimiAbstract:The Olfactory Sense is strongly related to memory and emotional processes. Studies on the effects of odor perception from brain activity have been conducted by using different neuro-imaging techniques. In this paper, we analyse electroencephalography (EEG) of 23 subjects during perceiving pleasant and unpleasant odor stimuli. We describe the construction of brain functional connectivity networks measured by most commonly used models. We discuss the network-based features of functional connectivity, and design classifiers by applying different functional connectivity network features. Finally, we show that pleasant and unpleasant emotions from Olfactory perceptions can be better classified if we see the brain as a nonlinear small-world network. By extracting appropriate features from functional connectivity networks, we manage to classify pleasant and unpleasant Olfactory perceptions with an average Kappa value of 0.11 ± 0.17, which is significantly non-random.
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Non-linear EEG features for odor pleasantness recognition
2014 Sixth International Workshop on Quality of Multimedia Experience (QoMEX), 2014Co-Authors: Eleni Kroupi, Dionisije Sopic, Touradj EbrahimiAbstract:Since Olfactory Sense is gaining ground in multimedia applications, it is important to understand the way odor pleasantness is perceived. Although several studies have explored the way odor pleasantness perception influences the power spectral density of the electroencephalography (EEG) in various brain regions, there are still no studies that investigate the way odor pleasantness perception affects the non-linear temporal variations of EEG. In this study two non-linear metrics are used, namely permutation entropy, and dimension of minimal covers, to explore the possibility of recognizing odor pleasantness perception from the non-linear properties of EEG signals. The results reveal that it is possible to discriminate between pleasant and unpleasant odors from the EEG nonlinear properties, using a Linear Discriminant Analysis classifier with cross-validation.
Hai Pham Dinh Minh - One of the best experts on this subject based on the ideXlab platform.
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Improvement of Olfactory display using solenoid valves
2007 IEEE Virtual Reality Conference, 2007Co-Authors: Takamichi Nakamoto, Hai Pham Dinh MinhAbstract:The research on Olfactory Sense in virtual reality has gradually expanded even though the technology is still premature. We have developed an Olfactory display composed of multiple solenoid valves. In the present study, an extended Olfactory display, where 32 component odors can be blended in any recipe, is described; the previous version has only 8 odor components. The size was unchanged even though the number of odor components was four times larger than that in the previous display. The complexity of blending was greatly reduced because of algorithm improvement. The blending method and the fundamental experiment using a QCM (quartz crystal microbalance) sensor are described here
Jungwook Choi - One of the best experts on this subject based on the ideXlab platform.
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A Study on the Development of Ubiquitous CellPhone Robot
2006 IEEE RSJ International Conference on Intelligent Robots and Systems, 2006Co-Authors: Dongik Oh, Yongrae Jung, Jaeil Choe, Jungwook ChoiAbstract:In this video clip, the development of ubiquitous CPR(Cellular Phone Robot), which adds personal robotic features such as mobility and emotion to CP(Cellular Phone), is presented. We described a prototype implementation of CPR and demonstrated its successful navigational ability. CPR movement are controlled by the data acquired from velocity sensors and the coordinates from RFID tags on the floor. Emotion modules of the CPR Interaction system stimulate human touch-Sense through vibrations, Olfactory-Sense through perfumes, and visual-Sense through motion patterns. Biometric signals of human can be effectively measured with ECG and EDR. Experimental results show these easy-to-mount on CPR Equipments are sufficient for generating reliable signal measurements. People will rely more and more on robotic assistants in the near future. Personal robots will lead the way to the new era. CPR provides a stepping stone.
