788 research outputs found
Social Bonds and the âSocial Premiumâ
Although Social bonds (SB) have witnessed an unprecedented increase especially since the
outburst of the Covid-19 pandemics, their performance vs. conventional bonds (CB) has not attracted
much attention. The aim of this paper is to test the existence, the sign and the determinants of a âsocial
premiumâ, defined as the yield differential between a SB and an otherwise identical CB. To this end
we set up a sample of 64 SB aligned with ICMA (International Capital Market Association) principles
and 64 matched CB, from October 2020 to October 2021 so as to focus on the peak of SB issuances.
We run regressions based on the idea that daily yield differential between SB and CB may be
determined by differences in un-matched characteristics. Based on the FE specification, which turns
out to be preferred vs. OLS and RE, a few main results emerge. First, as for the determinants, the
difference in liquidity and in volatility turn out to be significant: they are, respectively, negatively
and positively correlated with the yield differential. Second, on the whole sample the analysis of the
fixed effects, which represent the social premium, proves the existence of a significantly positive
social premium (1.242 bps). This result is robust to outliers, but differences emerge on subsamples.
Overall, the small magnitude of the social premium emerging from our analysis over the latter two
years would point to a (perhaps more mature) phase of the SB market, whereby the social feature
does not make otherwise comparable bonds any different in terms of yiel
TRS-measurements as a nondestructive method assessing stage of maturity and ripening in plum (Prunus domestica L.)
n plum fruit with dark red or blue blush colour covering the whole fruit, the change in ground colour from green to yellow during maturation and ripening is masked. Hence, the maturity stage is difficult to judge. Time-resolved reflectance spectroscopy (TRS) has been used as a nondestructive method to assess changes in important internal quality factors in âJubileumâ plums (Prunus domestica L.). Absorption coefficients (”a) and scattering coefficients (”s) were measured at both 670 and 758 nm during 5 days of storage. The changes in soluble solids content, titratable acidity and firmness were as expected. No change in soluble solids content was observed, while the plums became less acid and softer during storage. The TRS-measurements of plums indicated that TRS could give interesting information on internal quality factors in plums as the absorption at 670 nm was closely related to firmness, TA and TSS at the time of picking. Absorption at 758 nm was more closely related to the quality parameters after storage. The study did not indicate that scattering could be used in assessing maturity stage in plum
Optical Absorption and Scattering Phenomena in 'Jubileum' Plums in Relation to Their Colour Properties
Absorption and scattering of laser light pulse passing through the fruit determine among others, the optical properties of the product. Efforts have been made in the recent past to utilize innovative techniques such as time-resolved reflectance spectroscopy (TRS) to study the quality aspects of different fruit such as nectarines. These optical properties have been well related to firmness, sugars, acids and other quality attributes. TRS measurements were performed on âJubileumâ plums at two different wavelengths: 670 nm and 758 nm. The fruit were harvested in Norway and brought to Italy under protected conditions. After sorting the fruit by size, TRS measurements were made and the fruit were randomized for different examinations of quality aspects. It was observed that the absorption coefficient (”a) increased for both wavelengths as ripening progressed towards the melting stage of the fruit. The ”a values at 670 nm were higher than those at 758 nm. The higher rate in the ”a was distinguishable from the third day onwards as the fruit ripened. Similarly, it was interesting to note that the internal colour measured after destructing the fruit related well with the TRS absorption coefficient (”a), i.e., a decrease in the CIE L* (towards darker region) and b* (towards blue) value along with an increase in a* (towards red) from third day of storag
Feeding behaviour of larval European sea bass (Dicentrarchus labrax L.) in relation to temperature and prey density
The feeding behaviour of larval European sea bass (Dicentrarchus labrax, L.) was analysed in relation to temperature and prey
density under controlled laboratory conditions with the aim to assess the ability of larval fish to change the feeding tactic as a
response to environmental changes. Larvae were acclimated for 20 days at three different temperatures (19, 22 and 26°C), and
their feeding behaviour was then video-recorded in experimental trials, at two prey densities, consisting of swarms of 400/l
and 1440/l Artemia nauplii. Results showed that there was a significant effect of the interaction between temperature and prey
density on the proportion of swimming activity that was reduced at the high temperature-high prey density combination. This
suggested a switching in the larval feeding behaviour from an active to an ambush tactic, when the temperature reached 26°C
and the prey density was 1440 /l Artemia nauplii. These results are consistent with the current literature on fish larval behaviour
in showing that the foraging tactic can be modulated by the interaction of different abiotic and biotic factors characterising the
rearing environment
Financial fragility across Europe and the US: The role of portfolio choices, household features and economic-institutional setup
This paper investigates householdsâ financial fragility in twelve European countries and in the US by
employing the first wave of the Household Finance and Consumption Survey (HFCS) and the 2010
Survey of Consumer Finances (SCF), respectively. Financial fragility is defined by taking into account
both income constraints and portfolio composition (liquidity and indebtedness). Three main results
emerge. First, the estimation of bivariate probit models reveals that in all countries holding an illiquid
portfolio increases the likelihood of being financially fragile, while having a mortgage generally reduces
it. Second, there are relevant differences among countries in their estimated average probability of
financial fragility. Finally, decomposition of these differences by means of counterfactual methods
provides evidence of a significant role of the countryâs economic-institutional setup in providing a
safety net against financial fragility. This is more true in Europe than in the US
Development of a high-sensitivity torsion balance to investigate the thermal Casimir force
We report development of a high-sensitivity torsion balance to measure the
thermal Casimir force. Special emphasis is placed on experimental
investigations of a possible surface electric force originating from surface
patch potentials that have been recently noticed by several experimental
groups. By gaining a proper understanding of the actual contribution of the
surface electric force in real materials, we aim to undertake precision force
measurements to resolve the Casimir force at finite temperature in real metals,
as well as in other semiconducting materials, such as graphene.Comment: Proceedings of the 10th International Conference "Quantum Field
Theory Under the Influence of External Conditions"; 11 pages and 4 figure
Switching Casimir forces with Phase Change Materials
We demonstrate here a controllable variation in the Casimir force. Changes in
the force of up to 20% at separations of ~100 nm between Au and AgInSbTe (AIST)
surfaces were achieved upon crystallization of an amorphous sample of AIST.
This material is well known for its structural transformation, which produces a
significant change in the optical properties and is exploited in optical data
storage systems. The finding paves the way to the control of forces in
nanosystems, such as micro- or nanoswitches by stimulating the phase change
transition via localized heat sources.Comment: 7 pages, 3 figures The AFM images for the inset in Fig.2 were
replaced with new ones as obtained with tips having high aspect rati
Studies on classification models to discriminate âBraeburnâ apples affected by internal browning using the optical properties measured by time-resolved reflectance spectroscopy
This work aimed at studying the feasibility of time-resolved reflectance spectroscopy (TRS) to nondestructively detect internal browning (IB) in âBraeburnâ apples through the development of classification models based on absorption (ua) and scattering (us') properties of the pulp.This research was carried out in two seasons: in 2009, apples were measured by TRS at 670 nm and inthe 740â1040 nm spectral range on four equidistant points around the equator, whereas in 2010 appleswere measured by TRS at 670 nm and at 780 nm on eight equidistant points. The values of the absorption coefficients measured in the 670â940 nm range increased with IB devel-opment. On the contrary, us'780 was higher in healthy fruit than in IB ones. The ua780 also significantlyincreased with IB severity, showing high values when IB affected the pulp tissues compared to the coreones. Also ua670 changed with IB development, but it was not able to clearly discriminate healthy fruitfrom IB ones because its value was also affected by the chlorophyll content of the pulp. The absorption and scattering coefficients were used as explanatory variables in the linear discriminant analysis in order to classify each apple tissue as healthy or IB; then the models obtained were used forfruit classification. The best classification performance was obtained in 2010 using ua780 and us'780and considering the IB position within the fruit: 90% of healthy fruit and 71% of IB fruit were correctly classified. By using all the ua measured in the 670â1040 nm range plus the us'780, IB fruit classification was slightly better while healthy fruit classification was worse. The better result of 2010 was due tothe increased number of TRS measurement points that allowed better exploration of the fruit tissues. However, the asymmetric nature of this disorder makes detection difficult, especially when the disorderis localized in the inner part of the fruit (core) or when it occurs in spots. A different TRS set-up (position and distance of fibers, time resolution) should be studied in order to reach the deeper tissue within the fruit in order to improve browning detection
Spectrally Resolved Single-Photon Timing of Silicon Photomultipliers for Time-Domain Diffuse Spectroscopy
We characterized the single-photon timing response function of various silicon photomultipliers (SiPMs) over a broad (500-1100 nm) spectral range. We selected two SiPM manufacturers, and we investigated two active areas, i.e., a small (1-1.69 mm2 and a large (9 mm2) one, for each of them. We demonstrate that selected SiPMs are suitable for time-resolved diffuse optics (DO) applications where a very large detection area and sensitivity down to single photons are crucial to detecting the very faint return signal from biological tissues, like the brain, thus allowing replacement of photomultiplier tubes and opening the way to a novel generation of DO multichannel instrumentation. Due to our custom front-end electronics, we show the world's best single-photon timing resolution for SiPMs, namely, 57-ps full-width at half maximum for Hamamatsu 1.69 mm2 and 115 ps for Excelitas 9 mm2. Even further, we provide a thorough spectral investigation of the full single-photon timing response function, also detailing diffusion tails' time constants and dynamic range. The achieved insight and the reported performance open the way to a widespread diffusion of SiPMs not just in many-photon regimes (e.g., PET) but at single-photon counting regimes like DO as well
OVOL2 impairs RHO GTPase signaling to restrain mitosis and aggressiveness of Anaplastic Thyroid Cancer
Background: Anaplastic Thyroid Cancer (ATC) is an undifferentiated and aggressive tumor that often originates from well-Differentiated Thyroid Carcinoma (DTC) through a trans-differentiation process. Epithelial-to-Mesenchymal Transition (EMT) is recognized as one of the major players of this process. OVOL2 is a transcription factor (TF) that promotes epithelial differentiation and restrains EMT during embryonic development. OVOL2 loss in some types of cancers is linked to aggressiveness and poor prognosis. Here, we aim to clarify the unexplored role of OVOL2 in ATC. Methods: Gene expression analysis in thyroid cancer patients and cell lines showed that OVOL2 is mainly associated with epithelial features and its expression is deeply impaired in ATC. To assess OVOL2 function, we established an OVOL2-overexpression model in ATC cell lines and evaluated its effects by analyzing gene expression, proliferation, invasion and migration abilities, cell cycle, specific protein localization through immunofluorescence staining. RNA-seq profiling showed that OVOL2 controls a complex network of genes converging on cell cycle and mitosis regulation and Chromatin Immunoprecipitation identified new OVOL2 target genes. Results: Coherently with its reported function, OVOL2 re-expression restrained EMT and aggressiveness in ATC cells. Unexpectedly, we observed that it caused G2/M block, a consequent reduction in cell proliferation and an increase in cell death. This phenotype was associated to generalized abnormalities in the mitotic spindle structure and cytoskeletal organization. By RNA-seq experiments, we showed that many pathways related to cytoskeleton and migration, cell cycle and mitosis are profoundly affected by OVOL2 expression, in particular the RHO-GTPase pathway resulted as the most interesting. We demonstrated that RHO GTPase pathway is the central hub of OVOL2-mediated program in ATC and that OVOL2 transcriptionally inhibits RhoU and RhoJ. Silencing of RhoU recapitulated the OVOL2-driven phenotype pointing to this protein as a crucial target of OVOL2 in ATC. Conclusions: Collectively, these data describe the role of OVOL2 in ATC and uncover a novel function of this TF in inhibiting the RHO GTPase pathway interlacing its effects on EMT, cytoskeleton dynamics and mitosis
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