1,458 research outputs found
Polarization-based Light-Atom Quantum Interface with an All-optical Trap
We describe the implementation of a system for studying light-matter
interactions using an ensemble of cold rubidium 87 atoms, trapped in a
single-beam optical dipole trap. In this configuration the elongated shape of
the atomic cloud increases the strength of the collective light-atom coupling.
Trapping all-optically allows for long storage times in a low decoherence
environment. We are able to perform several thousands of measurements on one
atomic ensemble with little destruction. We report results on paramagnetic
Faraday rotations from a macroscopically polarized atomic ensemble. Our results
confirm that strong light-atom coupling is achievable in this system which
makes it attractive for single-pass quantum information protocols.Comment: 8 pages, 4 figure
Comparative Analysis of Gene Expression Data Reveals Novel Targets of Senescence-Associated microRNAs
In the last decades, cellular senescence is viewed as a complex mechanism involved in different processes, ranging from tumor suppression to induction of age-related degenerative alterations. Senescence-inducing stimuli are myriad and, recently, we and others have demonstrated the role exerted by microRNAs in the induction and maintenance of senescence, by the identification of a subset of Senescence-Associated microRNAs (SAmiRs) up-regulated during replicative or stress-induced senescence and able to induce a premature senescent phenotype when over-expressed in human primary cells. With the intent to find novel direct targets of two specific SAmiRs, SAmiR-494 and -486-5p, and cellular pathways which they are involved in, we performed a comparative analysis of gene expression profiles available in literature to select genes down-regulated upon replicative senescence of human primary fibroblasts. Among them, we searched for SAmiR’s candidate targets by analyzing with different target prediction algorithms their 3’UTR for the presence of SAmiR-binding sites. The expression profiles of selected candidates have been validated on replicative and stress-induced senescence and the targeting of the 3’UTRs was assessed by luciferase assay. Results allowed us to identify Cell Division Cycle Associated 2 (CDCA2) and Inhibitor of DNA binding/differentiation type 4 (ID4) as novel targets of SAmiR-494 and SAmiR-486-5p, respectively. Furthermore, we demonstrated that the over-expression of CDCA2 in human primary fibroblasts was able to partially counteract etoposide-induced senescence by mitigating the activation of DNA Damage Response
‘Implore me not, Dog’. The Dog in the Classical World: An Apotropaic View
In the Classical world, the dog has polysemic meaning, as proved by the analysis of poetic and ethological ancient sources. As a symbol of absolute fidelity to its owner, the dog stands for a fundamental iconographic marker for the aristocratic elfrepresentation,
but it can also be interpreted in a negative sense. The ambiguity gives it a liminal meaning, in which the symbolic value is intensified by its relationship to the gods, connected to the concept of passage from one state to another. This double aspect contributes to project an apotropaic sense onto itself, which remained in the Roman world until Late Antiquity
Loss of miR-107, miR-181c and miR-29a-3p promote activation of Notch2 signaling in pediatric high-grade gliomas (pHGGs)
The mechanisms by which microRNAs control pediatric high-grade gliomas (pHGGs) have
yet to be fully elucidated. Our studies of patient-derived pHGG tissues and of the pHGG cell line
KNS42 revealed down-regulation in these tumors of three microRNAs, specifically miR-107, miR-181c,
and miR-29a-3p. This down-regulation increases the proliferation of KNS42 cells by de-repressing
expression of the Notch2 receptor (Notch2), a validated target of miR-107 and miR-181c and a
putative target of miR-29a-3p. Inhibition (either pharmacologic or genetic) of Notch2 or re-expression
of the implicated microRNAs (all three combined but also individually) significantly reduced KNS42
cell proliferation. These findings suggest that Notch2 pathway activation plays a critical role in
pHGGs growth and reveal a direct epigenetic mechanism that controls Notch2 expression, which
could potentially be targeted by novel forms of therapy for these childhood tumors characterized by
high-morbidity and high-mortality
The Politics of Territory in Ethnically Polarized Cities: Looking for a Comparative Framework
Study of the Decay phi --> eta pi0 gamma with the KLOE detector
In a sample of 5.3x10^7 phi-decays observed with the KLOE detector at the
Frascati phi-factory Dafne we find 605 eta pi0 gamma events with eta -->
gamma\gamma and 197 eta pi0 gamma events with eta --> pi+ pi- pi0. The decay
phi --> eta pi0 gamma is dominated by the process phi --> a0 gamma. From a fit
to the eta pi0 mass spectrum we find BR(phi --> ao(980) gamma)= (7.4 +-
0.7)x10^-5.Comment: 12 pages, 6 figures, submitted to Phys.Lett.
Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals
We report the results of a search for axions from the 14.4 keV M1 transition
from Fe-57 in the core of the sun using the axio-electric effect in TeO2
bolometers. The detectors are 5x5x5 cm3 crystals operated at about 10 mK in a
facility used to test bolometers for the CUORE experiment at the Laboratori
Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg d of data was made
using a newly developed low energy trigger which was optimized to reduce the
detectors energy threshold. An upper limit of 0.63 c kg-1 d-1 was established
at 95% C.L.. From this value, a lower bound at 95% C.L. was placed on the
Peccei-Quinn energy scale of fa >= 0.76 10**6 GeV for a value of S=0.55 for the
flavor-singlet axial vector matrix element. Bounds are given for the interval
0.15 < S < 0.55.Comment: 14 pages, 6 figures, submitted to JCA
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