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See detailDifferential operators acting on tensor densities
Mathonet, Pierre ULg

Doctoral thesis (1998)

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See detailDifferential pathomechanisms of epidermal necrolytic blistering diseases.
Paquet, Philippe ULg; Pierard, Gérald ULg

in International Journal of Molecular Medicine (2002), 10(6), 695-9

Staphylococcal scalded skin syndrome (SSSS) results from the effect of exfoliative-toxins produced by staphylococcal strains. The disease affects predominantly children, and is rare in adults. We report ... [more ▼]

Staphylococcal scalded skin syndrome (SSSS) results from the effect of exfoliative-toxins produced by staphylococcal strains. The disease affects predominantly children, and is rare in adults. We report two cases of the adult type of SSSS. Corticotherapy, chronic alcohol abuse and epilepsy-related immune changes might have been predisposing factors in these patients. The immunopathological characteristics of the inflammatory cell infiltrate in adults SSSS have not been thoroughly explored so far in the literature. Biopsies from 2 patients with bullous SSSS skin were studied by means of immunochemistry using a panel of 10 antibodies directed to FXIIIa, CD15, CD31, CD45R0, CD50, CD54, CD62E, CD95, CD106, and L1-protein, respectively. Cutaneous biopsies from related blistering diseases were compared. They included drug-induced toxic epidermal necrolysis (TEN), bullous impetigo and superficial pemphigus. A dense cell infiltrate composed of granulocytes (CD15+), macrophages (L1 protein+) and memory T cells (CD45R0+) and a strong expression of ICAM-3 (CD50) were present in the epidermis. CD95+ keratinocytes were lining the intraepidermal blisters. Type I dermal dendrocytes (Factor XIIIa+) were numerous and plump in the dermis. Bullous impetigo exhibited the same pattern of inflammatory cells, but with a lower density in type I dermal dendrocytes. TEN differed from SSSS by both the absence of CD15+ granulocytes and a stronger expression of the pro-apoptotic CD95 antigen in the epidermis. In superficial pemphigus, CD95 antigen was not expressed, and CD15+ granulocytes, CD45R0+ lymphocytes and L1 protein+ monocytes were much less numerous. It is concluded that the specific binding of SSSS-induced exotoxins to the desmosomes alters the keratinocyte metabolism leading to an inflammatory reaction followed by focal apoptosis. Our findings are in line with the concept that SSSS exotoxins might be superantigens. A common pathomechanism leading to epidermal destruction is likely operative in SSSS and bullous impetigo. The inflammatory cell composition in TEN and superficial pemphigus markedly differs from that in SSSS. [less ▲]

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See detailDifferential Performance between Two Timber Species in Forest Logging Gaps and in Plantations in Central Africa
Fayolle, Adeline ULg; Ouedraogo, Dakis-Yaoba ULg; Ligot, Gauthier ULg et al

in Forests (2015), 6(2), 380-394

To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae), and of the non-pioneer ... [more ▼]

To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae), and of the non-pioneer light demander Pericopsis elata (assamela, Fabaceae) in logging gaps and in plantations in highly degraded areas in south-eastern Cameroon. The survival and size of each seedling was regularly monitored in the silvicultural experiments. Differences in performance and allometry were tested between species in logging gaps and in plantations. The two species performance in logging gaps was significantly different from plantations and concurred with the expectations of the performance trade-off hypothesis but not with the expectations of species light requirements. The pioneer M. excelsa survived significantly better in logging gaps while the non-pioneer P. elata grew significantly faster in plantations. The high mortality and slow growth of M. excelsa in plantations is surprising for a pioneer species but could be explained by herbivory (attacks from a gall-making psyllid). Identifying high-value native timber species (i) with good performance in plantations such as P. elata is of importance to restore degraded areas; and (ii) with good performance in logging gaps such as M. excelsa is of importance to maintain timber resources and biodiversity in production forests. [less ▲]

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See detailDifferential PIXE measurements for the stratigraphic analysis of the painting Madonna dei Fusi by Leonardo da Vinci
Grassi, Novella; Migliori, Alessandro; Mandò, PierAndrea et al

in X-Ray Spectrometry [=XRS] (2005), 34(4), 306-309

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See detailDifferential population studies using asteroseismology: Solar-like oscillating giants in CoRoT fields LRc01 and LRa01
Miglio, A.; Chiappini, C.; Morel, Thierry ULg et al

in European Physical Journal Web of Conferences (2013, March 01)

Solar-like oscillating giants observed by the space-borne satellites CoRoT and Kepler can be used as key tracers of stellar populations in the Milky Way. When combined with additional photometric ... [more ▼]

Solar-like oscillating giants observed by the space-borne satellites CoRoT and Kepler can be used as key tracers of stellar populations in the Milky Way. When combined with additional photometric/spectroscopic constraints, the pulsation spectra of solar-like oscillating giant stars not only reveal their radii, and hence distances, but also provide well-constrained estimates of their masses, which can be used as proxies for the ages of these evolved stars. In this contribution we provide supplementary material to the comparison we presented in Miglio et al. (2013) between populations of giants observed by CoRoT in the fields designated LRc01 and LRa01. [less ▲]

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See detailDifferential production of cytokines and activation of NF-kappa B in HPV-transformed keratinocytes
Havard, L.; Delvenne, Philippe ULg; Frare, P. et al

in Virology (2002), 298(2), 271-285

We have proposed that chronic infection of keratinocytes by HPV modifies the expression of potentially important cytokines by interfering with the NF-kappaB signal pathway We evaluated the constitutive ... [more ▼]

We have proposed that chronic infection of keratinocytes by HPV modifies the expression of potentially important cytokines by interfering with the NF-kappaB signal pathway We evaluated the constitutive and IL-1beta-induced expression of GM-CSF and TNF-alpha and the expression/activity of NF-kappaB in HPV+ and HPV- cell lines. Despite the enhanced expression of the functional components of the NF-kappaB signaling pathway in HPV+ cell lines by a mechanism implicating the HPV oncoprotein E6, the constitutive activity of NF-kappaB and the expression of GM-CSF/TNF-alpha were significantly reduced relative to the HPV- cell line and normal keratinocytes. In contrast, we observed a superactivation of NF-kappaB activity after IL-1beta stimulation, a strong and transient induction of GM-CSF/TNF-alpha mRNA, but undetectable levels of secreted proteins in HPV+ cell lines. Our data demonstrate that E6 modulates the NF-kappaB signaling pathway and suggest that other HPV proteins also interfere with GM-CSF/TNF-alpha expression by transcriptional and/or posttranscriptional mechanisms. (C) 2002 Elsevier Science (USA). [less ▲]

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See detailDifferential proteomic analysis of a human breast tumor and its matched bone metastasis identifies cell membrane and extracellular proteins associated with bone metastasis
Dumont, Bruno ULg; Castronovo, Vincenzo ULg; Peulen, Olivier ULg et al

in Journal of Proteome Research (2012)

The classical fate of metastasizing breast cancer cells is to seed and form secondary colonies in bones. The molecules closely associated with these processes are predominantly present at the cell surface ... [more ▼]

The classical fate of metastasizing breast cancer cells is to seed and form secondary colonies in bones. The molecules closely associated with these processes are predominantly present at the cell surface and in the extracellular space, establishing the first contacts with the target tissue. In this study, we had the rare opportunity to analyze a bone metastatic lesion and its corresponding breast primary tumor obtained simultaneously from the same patient. Using mass spectrometry, we undertook a proteomic study on cell surface and extracellular protein-enriched material. We provide a repertoire of significantly modulated proteins, some with yet unknown roles in the bone metastatic process as well as proteins notably involved in cancer cell invasiveness and in bone metabolism. The comparison of these clinical data with those previously obtained using a human osteotropic breast cancer cell line highlighted an overlapping group of proteins. Certain differentially expressed proteins are validated in the present study using immunohistochemistry on a retrospective collection of breast tumors and matched bone metastases. Our exclusive set of selected proteins supports the set-up of further investigations on both clinical samples and experimental bone metastasis models that will help to reveal the finely coordinated expression of proteins that favor the development of metastases in the bone microenvironment. [less ▲]

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See detailDifferential Regulation of Chondrocyte Metabolism by Oncostatin M and Interleukin-6
Sanchez, Christelle ULg; Deberg, Michelle ULg; Devel, Philippe et al

in Osteoarthritis and Cartilage (2004), 12(10), 801-10

OBJECTIVE: To determine the effects of interleukin (IL)-6 and oncostatin M (OSM) added separately or in combination with IL-1beta on human osteoarthritic (OA) chondrocytes in alginate beads. DESIGN: Human ... [more ▼]

OBJECTIVE: To determine the effects of interleukin (IL)-6 and oncostatin M (OSM) added separately or in combination with IL-1beta on human osteoarthritic (OA) chondrocytes in alginate beads. DESIGN: Human chondrocytes were isolated from OA cartilage and cultured in alginate beads for 12 days, in the absence or in the presence of increasing amounts of IL-6 (20-500ng/ml) with its soluble receptor or OSM (0.1-10ng/ml) and with or without IL-1beta (1.7ng/ml). Aggrecan (AGG), transforming growth factor-beta1 (TGF-beta1), stromelysin-1 [matrix metalloprotease (MMP)-3], tissue inhibitor of metalloproteinases-1 (TIMP-1), macrophage inflammatory protein-1 beta (MIP-1beta), IL-6 and IL-8 productions were assayed by specific enzyme amplified sensitivity immunoassays. Prostaglandin (PG)E(2) was measured by a specific radioimmunoassay and nitrite (NO(2)(-)) by a spectrophotometric method based upon the Griess reaction. RESULTS: OSM, but not IL-6, decreased basal AGG and TGF-beta1 synthesis. Although IL-6 stimulated basal TIMP-1 production, it did not significantly modify MMP-3/TIMP-1 ratio. In contrast, 10ng/ml OSM highly increased TIMP-1 production, and decreased by half the ratio MMP-3/TIMP-1. IL-1beta highly stimulated *NO, IL-8, IL-6, MIP-1beta and PGE(2) synthesis but decreased AGG and TGF-beta1 production. Neither IL-6 nor OSM modulated IL-1beta-inhibitory effect on AGG production. IL-6, but not OSM, reversed IL-1beta-induced TGF-beta1 inhibition. At 1-10ng/ml, OSM significantly decreased IL-1beta-stimulated IL-8, MIP-1beta, PGE(2) and *NO production but amplified IL-1beta stimulating effect on IL-6 production. IL-6 had no effect on these parameters. CONCLUSIONS: OSM and IL-6, two glycoprotein 130 binding cytokines, show different activity profiles on OA chondrocytes, indicating that these cytokines could play different roles in the OA disease process. [less ▲]

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See detailDifferential regulation of the REGγ–proteasome pathway by p53/TGF-β signalling and mutant p53 in cancer cells
Ali, Amjad ULg; Wang, Zhuo; Fu, Junjiang et al

in Nature Communications (2013)

Proteasome activity is frequently enhanced in cancer to accelerate metastasis and tumorigenesis. REGγ, a proteasome activator known to promote p53/p21/p16 degradation, is often overexpressed in cancer ... [more ▼]

Proteasome activity is frequently enhanced in cancer to accelerate metastasis and tumorigenesis. REGγ, a proteasome activator known to promote p53/p21/p16 degradation, is often overexpressed in cancer cells. Here we show that p53/TGF-β signalling inhibits the REGγ–20S proteasome pathway by repressing REGγ expression. Smad3 and p53 interact on the REGγ promoter via the p53RE/SBE region. Conversely, mutant p53 binds to the REGγ promoter and recruits p300. Importantly, mutant p53 prevents Smad3/N-CoR complex formation on the REGγ promoter, which enhances the activity of the REGγ–20S proteasome pathway and contributes to mutant p53 gain of function. Depletion of REGγ alters the cellular response to p53/TGF-β signalling in drug resistance, proliferation, cell cycle progression and proteasome activity. Moreover, p53 mutations show a positive correlation with REGγ expression in cancer samples. These findings suggest that targeting REGγ–20S proteasome for cancer therapy may be applicable to human tumours with abnormal p53/Smad protein status. Furthermore, this study demonstrates a link between p53/TGF-β signalling and the REGγ–20S proteasome pathway, and provides insight into the REGγ/p53 feedback loop. [less ▲]

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See detailDifferential regulation of the REGγ–proteasome pathway by p53/TGF-β signalling and mutant p53 in cancer cells
Ali, Amjad ULg; wang, zhou; Fu, Junjiang et al

in Nature Communications (2013), 1(4), 1-16

Proteasome activity is frequently enhanced in cancer to accelerate metastasis and tumorigenesis. REGγ, a proteasome activator known to promote p53/p21/p16 degradation, is often overexpressed in cancer ... [more ▼]

Proteasome activity is frequently enhanced in cancer to accelerate metastasis and tumorigenesis. REGγ, a proteasome activator known to promote p53/p21/p16 degradation, is often overexpressed in cancer cells. Here we show that p53/TGF-β signalling inhibits the REGγ–20S proteasome pathway by repressing REGγ expression. Smad3 and p53 interact on the REGγ promoter via the p53RE/SBE region. Conversely, mutant p53 binds to the REGγ promoter and recruits p300. Importantly, mutant p53 prevents Smad3/N-CoR complex formation on the REGγ promoter, which enhances the activity of the REGγ–20S proteasome pathway and contributes to mutant p53 gain of function. Depletion of REGγ alters the cellular response to p53/TGF-β signalling in drug resistance, proliferation, cell cycle progression and proteasome activity. Moreover, p53 mutations show a positive correlation with REGγ expression in cancer samples. These findings suggest that targeting REGγ–20S proteasome for cancer therapy may be applicable to human tumours with abnormal p53/Smad protein status. Furthermore, this study demonstrates a link between p53/TGF-β signalling and the REGγ–20S proteasome pathway, and provides insight into the REGγ/p53 feedback loop. [less ▲]

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See detailDifferential regulation of wild-type and mutant alpha-synuclein binding to synaptic membranes by cytosolic factors.
Wislet-Gendebien, Sabine ULg; Visanji, Naomi P; Whitehead, Shawn N et al

in BMC Neuroscience (2008), 9

BACKGROUND: Alpha-Synuclein (alpha-syn), a 140 amino acid protein associated with presynaptic membranes in brain, is a major constituent of Lewy bodies in Parkinson's disease (PD). Three missense ... [more ▼]

BACKGROUND: Alpha-Synuclein (alpha-syn), a 140 amino acid protein associated with presynaptic membranes in brain, is a major constituent of Lewy bodies in Parkinson's disease (PD). Three missense mutations (A30P, A53T and E46K) in the alpha-syn gene are associated with rare autosomal dominant forms of familial PD. However, the regulation of alpha-syn's cellular localization in neurons and the effects of the PD-linked mutations are poorly understood. RESULTS: In the present study, we analysed the ability of cytosolic factors to regulate alpha-syn binding to synaptic membranes. We show that co-incubation with brain cytosol significantly increases the membrane binding of normal and PD-linked mutant alpha-syn. To characterize cytosolic factor(s) that modulate alpha-syn binding properties, we investigated the ability of proteins, lipids, ATP and calcium to modulate alpha-syn membrane interactions. We report that lipids and ATP are two of the principal cytosolic components that modulate Wt and A53T alpha-syn binding to the synaptic membrane. We further show that 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16:0 PAF) is one of the principal lipids found in complex with cytosolic proteins and is required to enhance alpha-syn interaction with synaptic membrane. In addition, the impaired membrane binding observed for A30P alpha-syn was significantly mitigated by the presence of protease-sensitive factors in brain cytosol. CONCLUSION: These findings suggest that endogenous brain cytosolic factors regulate Wt and mutant alpha-syn membrane binding, and could represent potential targets to influence alpha-syn solubility in brain. [less ▲]

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See detailDifferential reinforcement of perching duration in the pigeon : a comparison with differential-reinforcement-of-low-rate key-pecking
Lejeune, Helga ULg; Richelle, Marc ULg

in Behaviour Analysis Letters (1982), 2

Pigeons were required to jump on a perch and sit on it for a specified duration before stepping off, in order to gain access to food. This duration was progressively increased by 1-sec steps. Median ... [more ▼]

Pigeons were required to jump on a perch and sit on it for a specified duration before stepping off, in order to gain access to food. This duration was progressively increased by 1-sec steps. Median response duration approximated the required repsonse duration up to values of 40 or even 50 sec and efficiency remained high. Response duration distribution had sharp peaks and comparable dispersions throughout the critical values range. These results contrast with the performance of the same birds in a conventional differential-reinforcement-of-low-rate schedule involving a key-peck response. This indicates that pigeons are able to regulate in time their own motor behaviour over much longer time intervals in the case of a perching response than in the case of key-pecking. [less ▲]

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See detailDifferential resistance/susceptibility patterns to pneumovirus infection among inbred mouse strains
Bui Tran Anh, Dao; Faisca, Rui-Pedro; Desmecht, Daniel ULg

in American Journal of Physiology - Lung Cellular and Molecular Physiology (2006), 291

Respiratory syncytial virus (RSV) is a prominent cause of airway morbidity in children under 1 yr of age. It is assumed that host factors influence the severity of the disease presentation and thus the ... [more ▼]

Respiratory syncytial virus (RSV) is a prominent cause of airway morbidity in children under 1 yr of age. It is assumed that host factors influence the severity of the disease presentation and thus the need for hospitalization. As a first step toward the identification of the underlying genes involved, this study was undertaken to establish whether inbred mouse strains differ in susceptibility to pneumonia virus of mice (PVM), the murine counterpart of RSV, which has been shown to accurately mimic the RSV disease of children. With this purpose in mind, double-chamber plethysmography and carbon monoxide uptake data were collected daily for 7 days after inoculation of PVM in six inbred strains of mice. In parallel, histological examinations and lung viral titration were carried out from day 5 to day 7 after inoculation. Pulmonary structure/function values reflected the success of viral replication in the lungs and revealed a pattern of continuous variation, with resistant, intermediate, and susceptible strains. The results suggest that SJL (resistant) and 129/Sv (susceptible) strains should be used in crossing experiments aimed at identifying genes controlling pneumovirus replication by the positional cloning approach. Similarly, crossing experiments using BALB/c or C57BL/6 (resistant) and DBA/2 or 129/Sv (susceptible) will allow the identification of the genes involved in the control of pulmonary inflammation during pneumovirus infection. [less ▲]

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See detailDifferential responsiveness between broiler and layer embryos upon different doses of L-carnitine administration. 1. Hatchability and blood parameters
Tona, K.; Nouboukpo, K. E.; Willemsen, H. et al

in Archiv Für Geglügelkunde = European Poultry Science = Revue de Science Avicole Européenne (2013), 77(4), 240-246

L-carnitine enhances the transport of long chain fatty acids through mitochondrial membrane. It can be produced by animals' organism from lysine and methionine. However, it was reported that chicken ... [more ▼]

L-carnitine enhances the transport of long chain fatty acids through mitochondrial membrane. It can be produced by animals' organism from lysine and methionine. However, it was reported that chicken embryos have a limited capacity to synthesize L-carnitine. For this study, hatching eggs from Ross and Isa Brown breeders of 35 wk old (600 eggs per line) were used. At d 18 of incubation, eggs from each genotype were divided into 4 groups i.e. control eggs, Saline (injection of saline solution), eggs injected with L-carnitine of 500 μmol (LC500) or 1000 μmol (LC1000). At hatch and 7 d post hatch, blood samples were collected for triglyceride, glucose, total protein, uric acids, triiodothyronine (T3), thyroxine (T4) and corticosterone concentrations determination. Results indicate that hatchability and percentage of chick of optimal quality were higher in Ross than Isa Brown. Overall, layer chicks had higher levels of T4, total protein and uric acid than broiler chicks. With regard to L-carnitine injection, eggs of LC1000 groups had the lowest hatchability and this negative effect was more pronounced in Isa Brown eggs. At hatch and 7 d post-hatch, control chicks had the lowest levels of triglyceride and T3 but the highest levels of T4. At 7 d-old, the highest and the lowest levels of corticosterone were obtained in chicks of LC1000 and LC500 groups, respectively, compared to control and saline groups. In conclusion, L-carnitine administration during embryonic life affected differentially hatchability and blood parameters during post-hatch juvenile growth and this in a dose dependent manner. © Verlag Eugen Ulmer, Stuttgart. [less ▲]

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See detailDifferential role of snail1 and snail2 zinc fingers in E-cadherin repression and epithelial to mesenchymal transition
Villarejo; Cortés-Cabrera, Alvaro; Molina Ortiz, Patricia ULg et al

in Journal of Biological Chemistry (2014), 289(2), 930-941

Snail1 (Snail) and Snail2 (Slug) are transcription factors that share a similar DNA binding structure of four and five C2H2 zinc finger motifs (ZF), respectively. Both factors bind specifically to a ... [more ▼]

Snail1 (Snail) and Snail2 (Slug) are transcription factors that share a similar DNA binding structure of four and five C2H2 zinc finger motifs (ZF), respectively. Both factors bind specifically to a subset of E-box motifs (E2-box: CAGGTG/CACCTG) in target promoters like the E-cadherin promoter and are key mediators of epithelial-to-mesenchymal transition (EMT). However, there are differences in the biological actions, in binding affinities to E-cadherin promoter, and in the target genes of Snail1 and Snail2, although the molecular bases are presently unknown. In particular, the role of each Snail1 and Snail2 ZF in the binding to E-boxes and in EMT induction has not been previously explored. We have approached this question by modeling Snail1 and Snail2 protein-DNA interactions and through mutational and functional assays of different ZFs. Results show that Snail1 efficient repression and binding to human and mouse E-cadherin promoter as well as EMT-inducing ability require intact ZF1 and ZF2, while for Snail2, either ZF3 or ZF4 is essential for those functions. Furthermore, the differential distribution of E2-boxes in mouse and human E-cadherin promoters also contributes to the differential Snail factor activity. These data indicate a non-equivalent role of Snail1 and Snail2 ZFs in gene repression, contributing to the elucidation of the molecular differences between these important EMT regulators. [less ▲]

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See detailDifferential roles of lipopeptides in plant host defenses and pathogen suppression.
Ongena, Marc ULg; Henry, G.; Jourdan, Emmanuel ULg et al

in Phytopathology (2010), 100

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See detailDifferential roles of lipopeptides(LPs) in plant host defenses and pathogen suppression.
Ongena, Marc ULg; Henry, G.; Jourdan, E. et al

Conference (2010)

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See detailDifferential Seismic Modeling of Stars
Ozel, N.; Mosser, B.; Dupret, Marc-Antoine ULg et al

in Astronomical Society of the Pacific Conference Series (2013, December 01)

CoRoT (Convection Rotation and planetary Transits) observations provide the opportunity to study a large sample of stars ranging from the Main Sequence (MS) to the Red Giant Branch. With the large ... [more ▼]

CoRoT (Convection Rotation and planetary Transits) observations provide the opportunity to study a large sample of stars ranging from the Main Sequence (MS) to the Red Giant Branch. With the large increase in the number of stars showing solar-like oscillations, we intend to extract as much information as possible from a low signal-to-noise ratio (SNR) oscillation spectrum, benefiting from comparison with a reference star having similar seismic and fundamental parameters. We propose a differential method to determine stellar properties of solar-like oscillations which we call “differential seismology of stellar twins”. [less ▲]

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See detailDifferential sensitivity of two insect GABA-gated chloride channels to dieldrin, fipronil and picrotoxinin
Le Corronch, Hervé; Alix, Philippe ULg; Hue, B

in Journal of Insect Physiology (2002), 48

In the central nervous system of both vertebrates and invertebrates inhibitory neurotransmission is mainly achieved through activation of gamma-aminobutyric acid (GABA) receptors. Extensive studies have ... [more ▼]

In the central nervous system of both vertebrates and invertebrates inhibitory neurotransmission is mainly achieved through activation of gamma-aminobutyric acid (GABA) receptors. Extensive studies have established the structural and pharmacological properties of vertebrate GABA receptors. Although the vast majority of insect GABA-sensitive responses share some properties with vertebrate GABAA receptors, peculiar pharmacological properties of these receptors led us to think that several GABA-gated chloride channels are present in insects. We describe here the pharmacological properties of two GABA receptor subtypes coupled to a chloride channel on dorsal unpaired median (DUM) neurones of the adult male cockroach. Long applications of GABA induce a large biphasic hyperpolarization, consisting of an initial transient hyperpolarization followed by a slow phase of hyperpolarization that is not quickly desensitized. With GABA, the transient hyperpolarization is sensitive to picrotoxinin, fipronil and dieldrin whereas the slow response is insensitive to these insecticides.When GABA is replaced by muscimol and cis-4-aminocrotonic acid (CACA) a biphasic hyperpolarization consisting of an initial transient hyperpolarization followed by a sustained phase is evoked which is blocked by picrotoxinin and fipronil. Exposure to dieldrin decreases only the early phase of the muscimol and CACA-induced biphasic response, suggesting that two GABA-gated chloride channel receptor subtypes are present in DUM neurones. This study describes, for the first time, a dieldrin resistant component different to the dieldrin- and picrotoxinin-resistant receptor found in several insect species. [less ▲]

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