691 research outputs found
Distribution et détection du Sirococcus clavigignenti-juglandacearum au Québec
La maladie du chancre du noyer cendré, causée par le Sirococcus clavigignenti-juglandacearum, affecte principalement le noyer cendré, Juglans cinerea, bien que le noyer noir, Juglans nigra, et les noyers hybrides puissent en être atteints. La maladie est présente dans plusieurs États américains ainsi qu'en Ontario et au Québec. Au Québec, elle a été rapportée pour la première fois en 1990, dans la région de Fort-Coulonge, en Outaouais. Depuis, de nouveaux foyers d'infection ont été notés en forêt naturelle ainsi que dans une plantation. En 1995, elle a été observée pour la première fois sur des semis de noyer dans deux pépinières forestières québécoises. Cette détection constitue le premier cas documenté de la maladie sur des semis de noyer cendré et de noyer noir dans des pépinières forestières.Although the Sirococcus canker of butternut, caused by Sirococcus clavigignenti-juglandacearum, has caused damage only to butternut, Juglans cinerea, black walnut, Juglans nigra, and hybrids of walnut are also susceptible to a certain degree. The disease is present in the United States, in Ontario and in Quebec. In Quebec, the disease was first reported in 1990 near Fort-Coulonge, in the Outaouais region. Since then, new infection sites have been observed in natural stands and in one plantation. In 1995, this disease was isolated for the first time from seedlings in two forest nurseries in Quebec. This constitutes the first report of the disease on butternut and black walnut seedlings in forest nurseries
Mirroring Pain in the Brain: Emotional Expression versus Motor Imitation
Perception of pain in others via facial expressions has been shown to involve brain areas responsive to self-pain, biological motion, as well as both performed and observed motor actions. Here, we investigated the involvement of these different regions during emotional and motor mirroring of pain expressions using a two-task paradigm, and including both observation and execution of the expressions. BOLD responses were measured as subjects watched video clips showing different intensities of pain expression and, after a variable delay, either expressed the amount of pain they perceived in the clips (pain task), or imitated the facial movements (movement task). In the pain task condition, pain coding involved overlapping activation across observation and execution in the anterior cingulate cortex, supplementary motor area, inferior frontal gyrus/anterior insula, and the inferior parietal lobule, and a pain-related increase (pain vs. neutral) in the anterior cingulate cortex/supplementary motor area, the right inferior frontal gyrus, and the postcentral gyrus. The 'mirroring' response was stronger in the inferior frontal gyrus and middle temporal gyrus/superior temporal sulcus during the pain task, and stronger in the inferior parietal lobule in the movement task. These results strongly suggest that while motor mirroring may contribute to the perception of pain expressions in others, interpreting these expressions in terms of pain content draws more heavily on networks involved in the perception of affective meaning
A Superheated Droplet Detector for Dark Matter Search
We discuss the operation principle of a detector based on superheated
droplets of Freon-12 and its feasibility for the search of weakly interacting
cold dark matter particles. In particular we are interested in a neutralino
search experiment in the mass range from 10 to 10^4 GeV/c^2 and with a
sensitivity of better than 10^-2 events/kg/d. We show that our new proposed
detector can be operated at ambient pressure and room temperature in a mode
where it is exclusively sensitive to nuclear recoils like those following
neutralino interactions, which allows a powerful background discrimination. An
additional advantage of this technique is due to the fact that the detection
material, Freon-12, is cheap and readily available in large quantities.
Moreover we were able to show that piezoelectric transducers allow efficient
event localization in large volumes.Comment: 15 pages LATEX; 11 figures on request from [email protected]
submitted to Nuclear Instruments and Methods
Dynamics in the deep Canada Basin, Arctic Ocean, inferred by thermistor chain time series
Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 37 (2007): 1066–1076, doi:10.1175/JPO3032.1.A 50-day time series of high-resolution temperature in the deepest layers of the Canada Basin in the Arctic Ocean indicates that the deep Canada Basin is a dynamically active environment, not the quiet, stable basin often assumed. Vertical motions at the near-inertial (tidal) frequency have amplitudes of 10– 20 m. These vertical displacements are surprisingly large considering the downward near-inertial internal wave energy flux typically observed in the Canada Basin. In addition to motion in the internal-wave frequency band, the measurements indicate distinctive subinertial temperature fluctuations, possibly due to intrusions of new water masses
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Membrane-initiated nuclear trafficking of the glucocorticoid receptor in hypothalamic neurons
Glucocorticoid binding to the intracellular glucocorticoid receptor (GR) stimulates the translocation of the GR from the cytosol to the nucleus, which leads to the transactivation or transrepression of gene transcription. However, multiple lines of evidence suggest that glucocorticoid signaling can also be initiated from the plasma membrane. Here, we provide evidence for membrane-initiated glucocorticoid signaling by a membrane-impermeant dexamethasone-bovine serum albumin (Dex-BSA) conjugate, which induced GR nuclear trafficking in hypothalamic neurons in vitro and in vivo. The GR nuclear translocation induced by a membrane-impermeant glucocorticoid suggests trafficking of an unliganded GR. The membrane-initiated GR trafficking was not blocked by inhibiting ERK MAPK, p38 MAPK, PKA, Akt, Src kinase, or calcium signaling, but was inhibited by Akt activation. Short-term exposure of hypothalamic neurons to dexamethasone (Dex) activated the glucocorticoid response element (GRE), suggesting transcriptional transactivation, whereas exposure to the Dex-BSA conjugate failed to activate the GRE, suggesting differential transcriptional activity of the liganded compared to the unliganded GR. Microarray analysis revealed divergent transcriptional regulation by Dex-BSA compared to Dex. Together, our data suggest that signaling from a putative membrane glucocorticoid receptor induces the trafficking of unliganded GR to the nucleus, which elicits a pattern of gene transcription that differs from that of the liganded receptor. The differential transcriptional signaling by liganded and unliganded receptors may contribute to the broad range of genetic regulation by glucocorticoids, and may help explain some of the different off-target actions of glucocorticoid drugs
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Multicenter assessment of quantitative sensory testing (QST) for the detection of neuropathic-like pain responses using the topical capsaicin model
Background: The use of quantitative sensory testing (QST) in multicenter studies has been quite limited, due in part to lack of standardized procedures among centers.
Aim: The aim of this study was to assess the application of the capsaicin pain model as a surrogate experimental human model of neuropathic pain in different centers and verify the variation in reports of QST measures across centers.
Methods: A multicenter study conducted by the Quebec Pain Research Network in six laboratories allowed the evaluation of nine QST parameters in 60 healthy subjects treated with topical capsaicin to model unilateral pain and allodynia. The same measurements (without capsaicin) were taken in 20 patients with chronic neuropathic pain recruited from an independent pain clinic.
Results: Results revealed that six parameters detected a significant difference between the capsaicin-treated and the control skin areas: (1) cold detection threshold (CDT) and (2) cold pain threshold (CPT) are lower on the capsaicin-treated side, indicating a decreased in cold sensitivity; (3) heat pain threshold (HPT) was lower on the capsaicin-treated side in healthy subjects, suggesting an increased heat pain sensitivity; (4) dynamic mechanical allodynia (DMA); (5) mechanical pain after two stimulations (MPS2); and (6) mechanical pain summation after ten stimulations (MPS10), are increased on the capsaicin-treated side, suggesting an increased in mechanical pain (P < 0.002). CDT, CPT and HPT showed comparable effects across all six centers, with CPT and HPT demonstrating the best sensitivity. Data from the patients showed significant difference between affected and unaffected body side but only with CDT.
Conclusion: These results provide further support for the application of QST in multicenter studies examining normal and pathological pain responses
A New Class of Non-Linear Stability Preserving Operators
We extend Br\"and\'en's recent proof of a conjecture of Stanley and describe
a new class of non-linear operators that preserve weak Hurwitz stability and
the Laguerre-P\'olya class.Comment: Fixed typos, spelling, and updated links in reference
A new class of coherent states with Meixner-Pollaczek polynomials for the Gol'dman-Krivchenkov Hamiltonian
A class of generalized coherent states with a new type of the identity
resolution are constructed by replacing the labeling parameter zn/n! of the
canonical coherent states by Meixner-Pollaczek polynomials with specific
parameters. The constructed coherent states belong to the state Hilbert space
of the Gol'dman-Krivchenkov Hamiltonian.Comment: 10 pages, Submitte
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