2,364 research outputs found
Xylem plasticity in Pinus pinaster and Quercus ilex growing at sites with different water availability in the Mediterranean region: relations between Intra-Annual Density Fluctuations and environmental conditions.
Fluctuations in climatic conditions during the growing season are recorded in Mediterranean tree-rings and often result in intra-annual density fluctuations (IADFs). Dendroecology and quantitative wood anatomy analyses were used to characterize the relations between the variability of IADF traits and climatic drivers in Pinus pinaster Aiton and Quercus ilex L. growing at sites with different water availability on the Elba island in Central Italy. Our results showed that both species present high xylem plasticity resulting in the formation of L-type IADFs (L-IADFs), consisting of earlywood-like cells in latewood. The occurrence of such IADFs was linked to rain events following periods of summer drought. The formation of L-IADFs in both species increased the hydraulic conductivity late in the growing season, due to their larger lumen area in comparison to "true latewood". The two species expressed greater similarity under arid conditions, as unfavorable climates constrained trait variation. Wood density, measured as the percentage of cell walls over total xylem area, IADF frequency, as well as conduit lumen area and vessel frequency, specifically in the hardwood species, proved to be efficient proxies to encode climate signals recorded in the xylem. The response of these anatomical traits to climatic variations was found to be species- and site-specific
Neutrons from Piezonuclear Reactions
We report the results obtained by cavitating water solutions of iron salts
(iron chloride and iron nitrate) with different concentrations at different
ultrasound powers. In all cases we detected a neutron radiation well higher
than the background level. The neutron production is perfectly reproducible and
can at some extent be controlled. These evidences for neutron emission
generated by cavitation support some preliminary clues for the possibility of
piezonuclear reactions (namely nuclear reactions induced by pressure and shock
waves) obtained in the last ten years. We have been able for the first time to
state some basic features of such a neutron emission induced by cavitation,
namely: 1) a marked threshold behavior in power, energy and time; 2) its
occurring without a concomitant production of gamma radiation.Comment: 8 figures; we added some more important references; we replaced some
figures with more detailed ones; we added more comprehensive details which
could not be desclosed before as part of private patents which have been
published no
Functional role of ambient GABA in refining neuronal circuits early in postnatal development
Early in development, \u3b3-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the mature brain, depolarizes and excites targeted neurons by an outwardly directed flux of chloride, resulting from the peculiar balance between the cation-chloride importer NKCC1 and the extruder KCC2. The low expression of KCC2 at birth leads to accumulation of chloride inside the cell and to the equilibrium potential for chloride positive respect to the resting membrane potential. GABA exerts its action via synaptic and extrasynaptic GABAA receptors mediating phasic and tonic inhibition, respectively. Here, recent data on the contribution of "ambient" GABA to the refinement of neuronal circuits in the immature brain have been reviewed. In particular, we focus on the hippocampus, where, prior to the formation of conventional synapses, GABA released from growth cones and astrocytes in a calcium- and SNARE (soluble N -ethylmaleimide-sensitive-factor attachment protein receptor)-independent way, diffuses away to activate in a paracrine fashion extrasynaptic receptors localized on distal neurons. The transient increase in intracellular calcium following the depolarizing action of GABA leads to inhibition of DNA synthesis and cell proliferation. Tonic GABA exerts also a chemotropic action on cell migration. Later on, when synapses are formed, GABA spilled out from neighboring synapses, acting mainly on extrasynaptic \u3b15, \u3b22, \u3b23, and \u3b3 containing GABAA receptor subunits, provides the membrane depolarization necessary for principal cells to reach the window where intrinsic bursts are generated. These are instrumental in triggering calcium transients associated with network-driven giant depolarizing potentials which act as coincident detector signals to enhance synaptic efficacy at emerging GABAergic and glutamatergic synapses. \ua9 2013 Cellot and Cherubini
Prion expression is activated by Adenovirus 5 infection and affects the adenoviral cycle in human cells
The prion protein is a cell surface glycoprotein whose physiological role remains elusive, while its implication
in transmissible spongiform encephalopathies (TSEs) has been demonstrated. Multiple interactions between
the prion protein and viruses have been described: viruses can act as co-factors in TSEs and life cycles of
different viruses have been found to be controlled by prion modulation.
We present data showing that human Adenovirus 5 induces prion expression. Inactivated Adenovirus did
not alter prion transcription, while variants encoding for early products did, suggesting that the prion is
stimulated by an early adenoviral function. Down-regulation of the prion through RNA interference showed
that the prion controls adenovirus replication and expression.
These data suggest that the prion protein could play a role in the defense strategy mounted by the host
during viral infection, in a cell autonomous manner. These results have implications for the study of the prion
protein and of associated TSEs
The E1B19K-deleted oncolytic adenovirus mutant Ad Delta 19K sensitizes pancreatic cancer cells to drug-induced DNA-damage by down-regulating Claspin and Mre11
This study was supported by a generous grant from
the UK charity Pancreatic Cancer Research Fund (PCRF)
and by the BCI CRUK Centre Grant [grant number
C16420/A18066]
Effects of Node Position on Lateral Bud Outgrowth in the Decapitated Shoot of Ipomoea nil
Author Institution: Department of Plant Biology, The Ohio State UniversityThe effects of node position and initial bud size on lateral bud outgrowth were studied following the release of apical dominance by decapitation of the main shoot of Ipomoea nil just above each of the first six nodes. Position effects were found. The greatest outgrowth occurred during a four-day period in the buds at the middle and higher nodes, with the least growth occurring in the bud at the lowest and oldest node. Variation in leaf number had no effect. Although initial bud size appears to have some influence over the outgrowth of lateral buds following decapitation, age and the associated factor of inhibitor content probably play a more significant role
SELSE, vers. 1.0”. Un Database in formato Microsoft ACCESS per la digitalizzazione dei dati raccolti con la Scheda “geologica” di II livello per la “Valutazione degli effetti locali nei siti di ubicazione di singoli edifici (edilizia ordinaria, strategica e monumentale)”
È stato realizzato un database relazionale (figura 1), denominato SELSE (Scheda Effetti
Locali per il Singolo Edificio), che consente la digitalizzazione delle informazioni rilevate con la scheda “geologica” per la “Valutazione degli effetti locali nei siti di ubicazione di singoli edifici” (di seguito indicata come scheda “Effetti Locali”; Compagnoni et al., 2009)
Accident Management in VVER-1000
The present paper deals with the investigation study on accident management in VVER-1000 reactor type conducted in the framework of a European Commission funded project. The mentioned study involved both experimental and computational fields. The purpose of this paper is to summarize the main findings from the execution of a wide-range analysis focused on AM in VVER-1000 with main regard to the qualification of computational tools and the proposal for an optimal AM strategy for this kind of NPP
Magnetic resonance findings and outcome in ten cats with traumatic spondylomyelopathy
In this retrospective study, the MR findings of ten cats with acute post-traumatic spondylomyelopathy were described and the most useful MR sequences were determined. Spinal cord injury (SCI), bone and muscle trauma were compared with the clinical outcome (recovery or euthanasia). The extension of spinal cord injury (SCI) was measured in vertebral body length (VBL). Of the ten cats, only five fully recovered. In the recovery group, no SCI (n=1) or SCI <1 VBL (n=4) were found. In the group of euthanized dogs, SCI > 2 VBLs (n=4) or spinal cord transection (n=1) were found. Lesions were best seen on T2WSE (spinal cord injury), STIR (soft tissue trauma) and T1WSE (bone injury). Low-field MR was therefore helpful to assess feline spinal trauma and may prove helpful to predict the clinical outcome, although a larger case series is needed. The authors suggest that protocols with low-field MR should include T1WSE, T2WSE and STIR sequences
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