Search results for "Nod"
showing 10 items of 4007 documents
Least energy solutions to the Dirichlet problem for the equation −D(u) = f (x, u)
2017
Let be a bounded smooth domain in RN. We prove a general existence result of least energy solutions and least energy nodal ones for the problem −u = f(x, u) in u = 0 on ∂ (P) where f is a Carathéodory function. Our result includes some previous results related to special cases of f . Finally, we propose some open questions concerning the global minima of the restriction on the Nehari manifold of the energy functional associated with (P) when the nonlinearity is of the type f(x, u) = λ|u| s−2u − μ|u| r−2u, with s, r ∈ (1, 2) and λ,μ > 0.
Kokemus elämänhallinnasta eläkkeelle siirryttäessä ja kolmannessa iässä
2008
Suomalaisen yhteiskunnan vanheneminen ja suurten ikäluokkien siirtyminen eläkkeelle ja kolmanteen ikään nostaa esille kysymyksiä, miten vastattaisiin tulevaisuuden palvelujen tarpeisiin ja miten palvelujärjestelmää olisi kehitettävä. Tutkimuksen tarkoitus on selvittää 60- ja 65-vuotiaiden ikääntyvien elämänhallintaa ja nykyistä sekä tulevaa tuen tarvetta. Elämänhallinnan viitekehyksenä on Antonovskyn koherenssiteoria, jossa elämänhallinta rakentuu merkityksellisyydestä, hallinnantunteesta ja ymmärrettävyydestä. Aineisto koostuu 35 Helsingin Vanhan kaupungin alueella asuvan henkilön haastattelusta. Haastateltavista enemmistö oli jo eläkkeellä, mutta osa oli vielä työelämässä. Haastattelu rak…
Ectopic hbox12 Expression Evoked by Histone Deacetylase Inhibition Disrupts Axial Specification of the Sea Urchin Embryo
2015
Dorsal/ventral patterning of the sea urchin embryo depends upon the establishment of a Nodal-expressing ventral organizer. Recently, we showed that spatial positioning of this organizer relies on the dorsal-specific transcription of the Hbox12 repressor. Building on these findings, we determined the influence of the epigenetic milieu on the expression of hbox12 and nodal genes. We find that Trichostatin-A, a potent and selective histone-deacetylases inhibitor, induces histone hyperacetylation in hbox12 chromatin, evoking broad ectopic expression of the gene. Transcription of nodal concomitantly drops, prejudicing dorsal/ventral polarity of the resulting larvae. Remarkably, impairing hbox12 …
Function of RAR? and RAR?2 at the initiation of retinoid signaling is essential for avian embryo survival and for distinct events in cardiac morphoge…
2003
Avian embryogenesis requires retinoid receptor activation by the vitamin A active form, retinoic acid (RA), during neurulation. We conducted loss-of-function analysis in quail embryos by nutritional deprivation of RA and by blocking generation of retinoid receptors. Here we identify a distinct role for RARα2 in cardiac inflow tract morphogenesis and for RARγ in cardiac left/right orientation and looping morphogenesis. Blocking normal embryos with antisense oligonucleotides to RARα2 or RXRα diminishes GATA-4 transcripts, while blocking RARγ or RXRα diminishes nodal and Pitx2 transcripts; the expression of these genes in the heart forming region resembles that of the vitamin A-deficient embry…
Early asymmetric cues triggering the dorsal/ventral gene regulatory network of the sea urchin embryo
2014
Dorsal/ventral (DV) patterning of the sea urchin embryo relies on a ventrally-localized organizer expressing Nodal, a pivotal regulator of the DV gene regulatory network. However, the inceptive mechanisms imposing the symmetry-breaking are incompletely understood. In Paracentrotus lividus, the Hbox12 homeodomain-containing repressor is expressed by prospective dorsal cells, spatially facing and preceding the onset of nodal transcription. We report that Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent transcription. Reciprocally, impairing hbox12 function disrupts DV polarity by allowing ectopic expression of nodal. Clonal loss-of-function, inflicted by b…
Overexpression of the truncated form of high mobility group a proteins (HMGA2) in human myometrial cells induces leiomyoma-like tissue formation
2014
The pathogenesis of uterine leiomyomas, the most common benign tumor in women, is still unknown. This lack of basic knowledge limits the development of novel non-invasive therapies. Our group has previously demonstrated that leiomyoma side population (SP) cells are present in tumor lesions and act like putative tumor-initiating stemcells in human leiomyoma. Moreover, accumulated evidence demonstrates that these benign tumors of mesenchymal origin are characterized by rearrangements of the High Mobility Group A proteins (HMGA). In this work, we tested the hypothesis that leiomyoma development may be due to overexpression of HMGA2 (encoding high mobility group AT-hook2) in myometrial stem cel…
Endoscopic ultrasound and early diagnosis of pancreatic cancer
2007
Incidence of pancreatic cancer has increased, but prognosis remains poor. Curative treatment is dependent on early diagnosis. Endoscopic ultrasound (EUS) has been described as highly sensitive and accurate in staging, superior to other imaging modalities in early publications. With rapid advances in technology, other imaging techniques have reached better results. EUS still has the highest accuracy in assessing tumor size and lymph node involvement. For assessment of tumor respectability, a combination of a computed tomography (CT) scan and EUS seems to be the procedure with the highest accuracy. Promising new techniques might improve the diagnostic yield of EUS. But there are several reaso…
Tumour vascularization via endothelial differentiation of glioblastoma stem-like cells
2010
Glioblastoma is a highly angiogenetic malignancy, the neoformed vessels of which are thought to arise by sprouting of pre-existing brain capillaries. The recent demonstration that a population of glioblastoma stem-like cells (GSCs) maintains glioblastomas indicates that the progeny of these cells may not be confined to the neural lineage. Normal neural stem cells are able to differentiate into functional endothelial cells. The connection between neural stem cells and the endothelial compartment seems to be critical in glioblastoma, where cancer stem cells closely interact with the vascular niche and promote angiogenesis through the release of vascular endothelial growth factor(VEGF) and str…
Enhancing carbon dots fluorescence via plasmonic resonance energy transfer
2022
Using plasmonic interactions to engineer optical properties at the nanoscale is an important challenge of current photonics. Here we establish a general strategy to enhance the orange emission of carbon dots by coupling them to gold nanoparticles through a polymeric spacer in solution. We exploit the overlap between the surface plasmon resonance of gold and the electronic transitions of carbon dots to achieve a fivefold increase of their fluorescence in the orange region, which is usually very weak. We demonstrate that this enhancement stems from an ultrafast resonance energy transfer from the coherent plasmonic state of the gold nanoantenna to the coupled carbon dot. Our study advances the…
ERCP : Energy-Efficient and Reliable-Aware Clustering Protocol for Wireless Sensor Networks
2022
Wireless Sensor Networks (WSNs) have been around for over a decade and have been used in many important applications. Energy and reliability are two of the major problems with these kinds of applications. Reliable data delivery is an important issue in WSNs because it is a key part of how well data are sent. At the same time, energy consumption in battery-based sensors is another challenge. Therefore, efficient clustering and routing are techniques that can be used to save sensors energy and guarantee reliable message delivery. With this in mind, this paper develops an energy-efficient and reliable clustering protocol (ERCP) for WSNs. First, an efficient clustering technique is proposed for…