757 research outputs found
A critique of full reserve banking
Proposals for full reserve banking have been put forward as a radical way of preventing further financial crises. They rest on the argument that crises are caused by excessive money supply growth brought about by inadequately controlled bank credit creation. Our aim is to provide a critique of the theoretical assumptions underlying the plans for full reserve banking. In particular some of the plans rely on the view that the money supply is a key causal variable and that it is feasible for central banks to identify and enforce an optimal quantity. Second, the plans all rely on an unsupported confidence in the efficiency of financial markets outside the centrally controlled banking system. Third, by removing profit-making opportunities from banks, the proposals may unduly tip the balance further in favour of shadow banking. Finally, as the case of 95% liquidity requirements on Kaupthing, Singer and Friedlander in the wake of the Great Financial Crash shows that modern financial engineering makes such policy-making difficult to execute. A Minskyan analysis rather emphasises the inherent instability of the financial system such that it is subject to systemic crises and the indeterminacy of demand for liquidity, while also emphasising the contribution prudent banking can make to financing economic activity and providing a safe money asset. While a return to a traditional separation of retail banking (regulated and supported by the central bank) from investment banking (regulated differently but not supported) would contribute to financial stability, it is argued that the full reserve banking proposals go too far
Overexpression of the nerve growth factor-inducible PC3 immediate early gene is associated with growth inhibition
PC3 (pheochromocytoma cell-3) is an immediate early gene isolated as sequence induced in the rat PC12 cell line during neuronal differentiation by nerve growth factor (NGF). PC3, which is expressed in vivo in the neuroblast when it ceases proliferating and differentiates into a neuron, has partial homology with two antiproliferative genes, BTG1 and Tob. Here we report that overexpression of PC3 in NIH3T3 and PC12 cells leads to marked inhibition of cell proliferation. In stable NIH3T3 clones expressing PC3, the transition from G1 to S phase was impaired, whereas the retinoblastoma (RB) protein was detected as multiple isoforms of M(r) 105,000-115,000 (indicative of a hyperphosphorylated state) only in low-density cultures. Such findings are consistent with a condition of growth inhibition. Thus, PC3 might be a negative regulator of cell proliferation, possibly acting as a transducer of factors influencing cell growth and/or differentiation, such as NGF, by a RB-dependent pathway. This is the first evidence of a NGF-inducible immediate early gene displaying antiproliferative activity
Photoreceptors' gene expression of Arabidopsis thaliana grown with biophilic LEDsourced lighting systems
Using specific photoreceptors, plants can sense light signals fundamental to their growth and development under changing light conditions. Phytochromes sense red and far-red light, cryptochromes and phototropins sense UV-A and blue light, while the UVR8 gene senses UV-B signals. The study of the molecular mechanisms used by plants to respond to artificial biophilic lighting is of pivotal importance for the implementation of biophilic approaches in indoor environments. CoeLux® is a new lighting system that reproduces the effect of natural sunlight entering through an opening in the ceiling, with a realistic sun perceived at an infinite distance surrounded by a clear blue sky. We used the model plant Arabidopsis thaliana to assess the gene expression of the main plant photoreceptors at different light intensities and at different times after exposure to the CoeLux® light type, using highpressure sodium (HPS) lamps as control light type. Genes belonging to different families of photoreceptors showed a similar expression pattern, suggesting the existence of a common upstream regulation of mRNA transcription. In particular, PHYA, PHYC, PHYD, CRY1, CRY2, PHOT1, and UVR8, showed a common expression pattern with marked differences between the two light types applied; under the HPS light type, the expression levels are raising with the decrease of light intensity, while under the CoeLux® light type, the expression levels remain nearly constant at a high fold. Moreover, we showed that under biophilic illumination the light spectrum plays a crucial role in the response of plants to light intensity, both at the molecular and morphological levels
Fusion of 40Ca + 40Ca, 40Ca + 48Ca and 48Ca + 48Ca
The recent experiment on fusion of 40 Ca + 40 Ca is described in some detail and the results are reported. A full excitation function has been measured from well above the Coulomb barrier, down to low energies where the cross section reduces to ≃20 µ b. A comparison is done with the recently published data on fusion of 40 Ca + 48 Ca and of 48 Ca + 48 Ca. The trends are different, in particular as far as the logarithmic derivatives (slopes) are concerned, in the interesting energy region below the barrier. The slope for systems where 40 Ca is involved, show a characteristic behavior with a tendency to saturate in a limited energy range just below the main barrier. The slopes resume increasing at lower energies, possibly indicating the influence of nuclear structure (the strong octupole vibration of 40 Ca) at such low energies, together with the clear presence of the fusion hindrance phenomenon. The results of coupled-channels calculations are presented
Oscillations above the barrier in the fusion of 28Si + 28Si
Fusion cross sections of 28Si + 28Si have been measured in a range above the
barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular
oscillations have been observed, best evidenced in the first derivative of the
energy-weighted excitation function. For the first time, quite different
behaviors (the appearance of oscillations and the trend of sub-barrier cross
sections) have been reproduced within the same theoretical frame, i.e., the
coupled-channel model using the shallow M3Y+repulsion potential. The
calculations suggest that channel couplings play an important role in the
appearance of the oscillations, and that the simple relation between a peak in
the derivative of the energy-weighted cross section and the height of a
centrifugal barrier is lost, and so is the interpretation of the second
derivative of the excitation function as a barrier distribution for this
system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters
Asymmetrical copper root pruning may improve root traits for reforesting steep and/or windy sites
Our research demonstrates that plant material can be produced in the nursery with asymmetrical root systems, which may have utility for reforestation of difficult planting sites characterized by steep slopes and/or windy conditions. Such a root system can be generated using chemical root pruning by applying cupric carbonate (Cu) that can arrest the development of, or cause mortality to, root apical meristems resulting in the formation of new lateral roots with an overall increase in the biomass, length, and volume of the root system. Our objective was to investigate the effect of chemical root pruning on the morphological and architectural traits of adventitious roots produced by poplar cuttings (Populus nigra L.) grown in containers coated with Cu in various symmetrical (Side, Bottom, Side + Bottom) and asymmetrical (half side + half bottom) patterns. After six weeks, roots of the cuttings were extracted from different container depths (Top, Middle, and Bottom) and portions (non-coated, Cu-coated), and analyzed. The root systems reacted to all coating patterns by increasing length, biomass, volume, and average diameters, but magnitude of increase was further affected by depth. In particular, root growth was unaffected at the Top of the container, and length was the highest at the Bottom depth. The Middle depth had a significant increment in both biomass and volume. Also, the root population increased in diameter as a possible response to Cu exposure. Interestingly, in the asymmetrically coated containers this depth response in the non-coated portions was of higher magnitude than in the Cu-coated portions
Effect of tree density on root distribution in Fagus sylvatica stands: a semi-automatic digitising device approach to trench wall method
5Knowledge of root profiles is essential for
measuring and predicting ecosystem dynamics and function.
In the present study, the effects of management
practices on root (0.5 <= ø < 20 mm) spatial distribution
were examined in a 40-year-old coppice stand (CpS 1968)
and other two stands converted from coppice to thinned
high forest in 1994 (CvS 1994) and 2004 (CvS 2004),
respectively. The use of a semi-automatic digitising device
approach was compared with a conventional root mapping
method in order to estimate the time per person required
from fieldwork to the final digital map. In July 2009, six
trench walls per stand were established according to tree
density, i.e. as equidistant as possible from all surrounding
trees. Findings highlighted differences between the stands
with CvS 1994 showing a lower number of small roots
(2 <= ø < 5 mm), a higher mean cross-sectional area
(CSA) of coarse roots (5 <= ø < 20 mm) and different root
depth distribution as compared to CpS 1968 and CvS 2004
whose values were close to each other. The three diameter
classes selected in this study showed significant relationships
in terms of number of roots, scaling down from
coarse- to small- and fine-roots. Forest management
practices significantly affected only the number of small
roots. The number of fine roots (0.5 <= ø < 2 mm) was isometrically related to their root length density (RLD,
cm cm-3). No relationship occurred with RLD of very fine
roots (ø < 0.5 mm). In conclusion, forest management
practices in terms of conversion thinnings significantly
affected belowground biomass distribution of beech forest
in space and time. In particular, frequency of coarse roots
was related to the stand tree density, frequency of small
roots was related to the cutting age. Size of coarse roots
was related to tree density but only several years after
felling. The allometric relationship occurring between fineand
small-roots highlighted how fine root number and RLD
were only indirectly affected by forest management practices.
These findings suggest that future investigations on
the effect of forest thinning practices on fine-root traits like
number, length and biomass several years after felling
cannot ignore those on small roots.openDi Iorio, A.; Montagnoli, A.; Terzaghi, M.; Scippa, G.S.; Chiatante, D.DI IORIO, Antonino; Montagnoli, A.; Terzaghi, M.; Scippa, G. S.; Chiatante, Donat
Fine-root seasonal pattern, production and turnover rate of European beech (Fagus sylvatica L.) stands in Italy Prealps: Possible implications of coppice conversion to high forest
The aim of this study was to investigate the possible effects of coppice conversion to high forest on the beech fine-root
systems. We compared the seasonal pattern of live and dead fine-root mass (d<2 mm), production and turnover in three
beech stands that differed in management practices. Tree density was higher in the 40-year-old coppice stand than in the
stands that were converted from coppice to high forest in 1994 and 2004, respectively. We found that a reduction in tree
density reduced the total fine-root biomass (Coppice stand, 353.8 g m-2; Conversion 1994 stand, 203.6 g m-2;
Conversion 2004 stand, 176.2 g m-2) which continued to be characterised by a bimodal pattern with two major peaks,
one in spring and one in early fall. Conversion to high forest may also affect the fine-root soil depth distribution. Both
fine-root production and turnover rate were sensitive to management practices. They were lower in the Coppice stand
(production 131.5 g m-2 year-1; turnover rate 0.41 year-1) than in the converted stands (1994 Conversion stand:
production 232 g m-2 year-1, turnover rate 1.06 year-1; 2004 Conversion stand: production 164.2 g m-2 year-1,
turnover rate 0.79 year-1)
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