Search results for "Bulb"
showing 10 items of 179 documents
Andromonoecy and developmental plasticity in Chaerophyllum bulbosum (Apiaceae–Apioideae)
2013
Background and Aims: Andromonoecy, the presence of hermaphrodite and male flowers in the same individual, is genetically fixed or induced, e.g. by fruit set. Little is known about the forces triggering andromonoecy in the Apiaceae. In the present study, a natural population of the protandrous Chaerophyllum bulbosum was investigated to elucidate architectural constraints and effects of resource reallocation. Methods: Three sets of plants (each n ¼ 15) were treated by hand pollination, pollinator exclusion and removal of low-order inflorescences. Fifteen untreated plants were left as controls. Key Results: Untreated plants produce umbels up to the third branch order, with increasing proportio…
Chromatin remodelling factor Mll1 is essential for neurogenesis from postnatal neural stem cells
2009
Epigenetic mechanisms that maintain neurogenesis throughout adult life remain poorly understood(1). Trithorax group (trxG) and Polycomb group (PcG) gene products are part of an evolutionarily conserved chromatin remodelling system that activate or silence gene expression, respectively(2). Although PcG member Bmi1 has been shown to be required for postnatal neural stem cell self-renewal(3,4), the role of trxG genes remains unknown. Here we show that the trxG member Mll1 (mixed-lineage leukaemia 1) is required for neurogenesis in the mouse postnatal brain. Mll1-deficient subventricular zone neural stem cells survive, proliferate and efficiently differentiate into glial lineages; however, neur…
Sparse Distributed Representation of Odors in a Large-scale Olfactory Bulb Circuit
2013
In the olfactory bulb, lateral inhibition mediated by granule cells has been suggested to modulate the timing of mitral cell firing, thereby shaping the representation of input odorants. Current experimental techniques, however, do not enable a clear study of how the mitral-granule cell network sculpts odor inputs to represent odor information spatially and temporally. To address this critical step in the neural basis of odor recognition, we built a biophysical network model of mitral and granule cells, corresponding to 1/100th of the real system in the rat, and used direct experimental imaging data of glomeruli activated by various odors. The model allows the systematic investigation and g…
Dynamic Changes in the Neurogenic Potential in the Ventricular–Subventricular Zone of Common Marmoset during Postnatal Brain Development
2020
AbstractEven after birth, neuronal production continues in the ventricular–subventricular zone (V–SVZ) and hippocampus in many mammals. The immature new neurons (“neuroblasts”) migrate and then mature at their final destination. In humans, neuroblast production and migration toward the neocortex and the olfactory bulb (OB) occur actively only for a few months after birth and then sharply decline with age. However, the precise spatiotemporal profiles and fates of postnatally born neurons remain unclear due to methodological limitations. We previously found that common marmosets, small nonhuman primates, share many features of V–SVZ organization with humans. Here, using marmosets injected wit…
Second Generation of Freescoo Solar DEC Prototypes for Residential Applications
2015
Freescoo is an innovative all-in-one compact solar Desiccant Evaporative Cooling (DEC) air conditioner concept. Results of the first prototype developed were presented at SHC Conference last year. Now a second generation of freescoo prototypes for applications in residential and small office buildings have been installed in Italy at ENEA Casaccia and at UNIPA. The thermodynamic cycle is based on the use of fixed and cooled adsorption beds and advanced evaporative cooling concepts. The adsorption bed, which is a fin and tube heat exchanger packed with silica gel grains, allows simultaneous dehumidification and cooling of the process air. The indirect evaporative cooling process, operated dow…
Imaging of nitric oxide in a living vertebrate using a diaminofluorescein probe
2007
Abstract Numerous approaches have been described to identify nitric oxide (NO), a free radical involved in various physiological and pathophysiological processes. One of these approaches is based on the use of chemical probes whose transformation by NO generates highly fluorescent derivatives, permitting detection of NO down to nanomolar concentrations. Here, we show that the cell-permeant diaminofluorophore 4-amino-5-methylamino-2′-7′-difluorofluorescein diacetate (DAF-FM-DA) can be used to detect NO production sites in a living vertebrate, the zebrafish Danio rerio. The staining pattern obtained in larvae includes the bulbus arteriosus, forming bones, the notochord, and the caudal fin. Th…
Urethroplasty with dorsal buccal mucosa graft. Is it still the method of choice in long term urethral stenosis?
2017
The aim of our work was to evaluate the long-term changes in symptoms (median 42 months) and to analyze data for any negative predictive factors for the application of the procedure, in patients who underwent to urethroplasty with dorsal buccal mucosa graft. During the period from 2010 to 2015 27 patients were examined. Than they underwent urethroplasty using dorsal buccal mucosa graft (graft of 4 x 2.5 cm). The evaluation of symptoms has been addressed through the application of the IPSS Quality of Life Questionnaire (International Prostatic Symptoms Score) and the evaluation of urinary flow has been carried out by a comparative analysis between the pre- and post-operative uroflowmetry. As…
Peroxisome proliferator-activated receptor γ ligands regulate neural stem cell proliferation and differentiation in vitro and in vivo.
2011
Peroxisome proliferator-activated receptor gamma (PPARγ) belongs to a family of ligand-activated nuclear receptors and its ligands are known to control many physiological and pathological situations. Its role in the central nervous system has been under intense analysis during the last years. Here we show a novel function for PPARγ in controlling stem cell expansion in the adult mammalian brain. Adult rats treated with pioglitazone, a specific ligand of PPARγ, had elevated numbers of proliferating progenitor cells in the subventricular zone and the rostral migratory stream. Electron microscopy analysis also showed important changes in the subventricular zone ultrastructure of pioglitazone-t…
Subventricular Zone-Derived Neuroblasts Migrate and Differentiate into Mature Neurons in the Post-Stroke Adult Striatum
2006
Recent studies have revealed that the adult mammalian brain has the capacity to regenerate some neurons after various insults. However, the precise mechanism of insult-induced neurogenesis has not been demonstrated. In the normal brain, GFAP-expressing cells in the subventricular zone (SVZ) of the lateral ventricles include a neurogenic cell population that gives rise to olfactory bulb neurons only. Herein, we report evidence that, after a stroke, these cells are capable of producing new neurons outside the olfactory bulbs. SVZ GFAP-expressing cells labeled by a cell-type-specific viral infection method were found to generate neuroblasts that migrated toward the injured striatum after middl…
Magnetic resonance imaging of the migration of neuronal precursors generated in the adult rodent brain
2006
Neural progenitor cells (NPCs) reside within the subventricular zone (SVZ) in rodents. These NPCs give rise to neural precursors in adults that migrate to the olfactory bulb (OB) along a well-defined pathway, the rostral migratory stream (RMS). Here we demonstrate that these NPCs can be labeled, in vivo, in adult rats with fluorescent, micron-sized iron oxide particles (MPIOs), and that magnetic resonance imaging (MRI) can detect migrating neural precursors carrying MPIOs along the RMS to the OB. Immunohistochemistry and electron microscopy indicated that particles were inside GFAP(+) neural progenitor cells in the SVZ, migrating PSA-NCAM(+) and Doublecortin(+) neural precursors within the …