6,503 research outputs found
Dental pulp stem cells bioadhesivity: evaluation on mineral-trioxide-aggregate.
Stem cells are undifferentiated cells that have the capacity to self-renew. They have been discovered in many adult tissues, including teeth. Dental Pulp Mesenchymal Stem Cells (DP-MSCs) are involved in dental repair by activation of growth factors, released after caries and have the ability to regenerate a dentin-pulp-like complex. The molecular/cellular research gives the possibility to grow new tissues and biological structures for clinical applications, providing cells for therapies including cell transplantation and tissue engineering. In this study DP-MSCs were derived from dental pulp of 10 donors. To evaluate material toxicity, after in vitro isolation, the cells were seeded on mineral trioxide aggregate (MTA). Initial light microscopy investigation of cells revealed no signs of cell death due to toxicity or infection, on the contrary the scaffolds supplied an excellent support for cell structures, the cells proliferated and adhered to substrate. Similar observation was seen in scanning electron microscopy, in particular the cells had proliferated and spread, covering a considerable part of the surface of the biomaterials investigated, with an elaborate form of attachment, in fact, the cells formed a continuous layer on the upper surface of the MTA. In conclusion, the aim of this study is to demonstrate that DP-MSCs combined with MTA could be a potential source for regenerative medicine, encouraging further study to evaluate the new-dentin formation
Influence of soil temperature and water content on fine-root seasonal growth of European beech natural forest in Southern Alps, Italy
In tree species, fine-root growth is influenced by the interaction between environmental factors such as soil temperature (ST) and soil moisture. Evidences suggest that if soil moisture and nutrient availability are adequate, rates of root growth increase with increasing soil temperature up to an optimum and then decline at supraoptimal temperatures. These optimal conditions vary between different taxa, the native environment and the fine-root diameter sub-classes considered. We investigated the effects of seasonal changes of both ST and soil water content (SWC) on very fine (d < 0.5 mm) and fine-root (0.5 < d < 2 mm) mass (vFRM, FRM) and length (vFRL, FRL) in Italian Southern Alps beech forests (Fagus sylvatica L.). Root samples were collected by soil core method. Turnover rate was higher for the very fine (0.51) than for the fine (0.36) roots. vFRM, FRM, vFRL and FRL displayed a complex seasonal pattern peaking in summer when SWC was around 40 % and ST was around 14 \ub0C. Above this temperature, under almost constant SWC, all above mentioned root traits decreased. vFRM, FRM, vFRL and FRL showed significant second-order polynomial relationship (p < 0.05) with SWC for both diameter classes, with the only exception of SRL. ST showed the same kind of relationship significant only with vFRM and vFRL, the latter within the 12-16 \ub0C smaller range. Interpolation analysis between root mass and length for both diameter classes and investigated soil environmental characteristics (ST and SWC) showed a clear roundish delineation only for vFRM. In conclusion, these findings clarified the occurrence of a bimodal fine-root growth seasonal pattern for our beech forest. The optimal growth ST and SWC ranges were delineated only for very fine roots, giving further evidence on this root category as the more responsiveness to soil environmental changes. Furthermore, F. sylvatica seems to adopt an intensive strategy to cope with decreasing SWC. Finally, fine-root growth, mainly radial type, seems to be driven by SWC, whereas very fine-root growth, mainly longitudinal type, seems to be driven by ST
Root seasonal pattern, spatial distribution, and C:N ratio of matgrasspasture (Nardus stricta L.) in the Lombardy Prealps
The aim of the present study was to investigate carbon and nutrient cycling and the role of root dynamics in terrestrial
ecosystems such as large abandoned pastures and natural grasslands present in the Prealps, for which below-ground
processes are currently enigmatic. In particular, we quantified root/leaf biomass and C:N ratio throughout two growing
seasons. Additionally, root traits such as root length density (RLD), root mass density (RMD), and root diameter classes
(RDC) were also investigated with the aim of understanding the spatial distribution of roots in the soil. In our samples, we
found that the roots could be divided into three main diameter classes and hence quantified the presence of each class along
the soil profile. With regard to total root biomass, we found the occurrence of two peaks of biomass accumulation during
the growth season, and when biomass accumulation was compared with climatic data, it was impossible to obtain a clear
indication of the root turnover rate. In fact, the strong influence of grazing on the above-ground biomass could have
affected, in turn, root biomass. In future, this possible complication will be avoided by repeating the measurements within
enclosures to avoid grazing interference. We found that C:N ratio remained constant, with a single peak, suggesting a lower
root decomposition during the warmest period (August 2006). The concentration of nitrogen in roots decreased with depth
as a result of a decrease in roots with smaller diameters. The reverse was found for carbon content, which increased with
depth, probably due to an increase in roots with larger diameters. This study represents the first attempt to estimate root
turnover rates in this prealpine ecosystem, which have been analysed to date only for the above-ground biomass
Fine-root carbon and nitrogen concentration of European beech (Fagus sylvatica L.) in Italy Prealps: possible implications of coppice conversion to high forest
Fine-root systems represent a very sensitive plant compartment to environmental changes. Gaining further knowledge about their dynamics would improve soil carbon input understanding. This paper investigates C and N concentrations in fine roots in relation to different stand characteristics resulting from conversion of coppiced forests to high forests. In order to evaluate possible interferences due to different vegetative stages of vegetation, fine-root sampling was repeated six times in each stand during the same 2008 growing season. Fine-root sampling was conducted within three different soil depths (0-10; 10-20; and 20-30 cm). Fine-root traits were measured by means of WinRHIZO software which enable us to separate them into three different diameter classes (0-0.5, 0.5-1.0 and 1.0-2.0 mm). The data collected indicate that N concentration was higher in converted stands than in the coppiced stand whereas C concentration was higher in the coppiced stand than in converted stands. Consequently the fine-root C:N ratio was significantly higher in coppiced than in converted stands and showed an inverse relationship with fine-root turnover rate, confirming a significant change of fine-root status after the conversion of a coppice to high forest
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)
Investment portfolios and three dimensions of real estate investment: an Australian perspective
Real estate offers a range of investment alternatives for mutual funds including residential real estate, commercial real estate and units in listed real estate investment trusts (REITs). Our quartery total return data spans the period from the 3rd quarter 1986 to the 3rd quarter 2009 using various combinations of the Australian All Ordinaries share price index and these three classes of real estate investment. Comparison of Sharpe and Sortino (downside risk) measures across a range of portfolios suugest that diversification benefits may be achieved through diversifying into real estate investment, particularly direct investment in residential real estate, given an initial exposure to the equity market
Preliminary analysis of Stearoyl Co-A Desaturase gene transcripts in River buffalo
Stearoyl-CoA desaturase (SCD) is a key enzyme in the biosynthesis of monounsaturated fatty acids (MUFAs). In cattle, SCD gene extends over a DNA segment of ~17.0 Kb, and it is organized in 6 exons and 5 introns. The SCD gene has been indicated as the candidate gene to change the saturated/unsaturated FAs ratio and hence it has been suggested as the gene influencing the fat quality. In cattle, eight SNPs have been identified and one of them, (T→C) at 231st nt of 5th exon, is responsible for the Val→Ala amino acid change. The C allele has been associated with higher content of MUFAs in carcasses, and it is positively related to a higher index of desaturation (C18:0/C18:1 and C16:0/C16:1) in the milk. In this study, we report on preliminary results of analysis of transcripts of the SCD encoding gene in river buffalo. The electrophoretic analysis of the RT-PCR products and the subsequent sequencing showed at least five different populations of mRNA. The most represented population is correctly assembled (~1300 bp), followed by the one which is deleted of ~750bp, corresponding to the 3rd, 4th and 5th exon and partially to the 2nd and 6th exon
Sarcopenia: age-related skeletal muscle changes from determinants to physical disability.
Human aging is characterized by skeletal muscle wasting, a debilitating condition which sets the susceptibility for diseases that directly affect the quality of life and often limit life span. Sarcopenia, i.e. the reduction of muscle mass and/or function, is the consequence of a reduction of protein synthesis and an increase in muscle protein degradation. In addition, the capacity for muscle regeneration is severely impaired in aging and this can lead to disability, particularly in patients with other concomitant diseases or organ impairment. Immobility and lack of exercise, increased levels of proinflammatory cytokines, increased production of oxygen free radicals or impaired detoxification, low anabolic hormone output, malnutrition and reduced neurological drive have been advocated as being responsible for sarcopenia. It is intriguing to notice that multiple pathways converge on skeletal muscle dysfunction, but the factors involved sometimes diverge to different pathways, thus intersecting at critical points. It is reasonable to argue that the activity of these nodes results from the net balance of regulating mechanisms, as in the case of the GH/IGF-1 axis, the testosterone and Cortisol functions, the pro- and anti-inflammatory cytokines and receptors. Both genetic and epigenetic mechanisms operate in regulating the final phenotype, the extent of muscle atrophy and reduction in strength and force generation. It is widely accepted that intervention on lifestyle habits represents an affordable and practical way to modify on a large scale some detrimental outcomes of aging, and particularly sarcopenia. The identification of the molecular chain able to reverse sarcopenia is a major goal of studies on human aging
Poplar woody root proteome during the transition dormancy-active growth
Woody plants living in temperate climates finely regulate their growth and development in relation to seasonal changes; their
transition from vegetative to dormancy phase represents an adaptation to their environment. Events occurring in the shoot
during onset/release from dormancy have been largely investigated, whereas in woody roots they remain completely
unknown. In recent years, we have been interested in understanding the molecular and physiological events occurring in
poplar woody root during release from dormancy. Here, we propose the results of a comparative analysis of the proteome of
poplar woody root sampled at different time points: T0 (dormancy condition), T1 (release from dormancy), and T2 (full
vegetative condition). This study identified proteins that may be involved in the long-term survival of a dormant root or
landmarking a specific time point
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