2,708 research outputs found
Student Recital: Felicia I. Colvin, Soprano; Skip Buss, Piano; February 23, 1975
Centennial East Recital HallSunday AfternoonFebruary 23, 19754:00 p.m
Environmental enrichment extends photoreceptor survival and visual function in a mouse model of retinitis pigmentosa
Slow, progressive rod degeneration followed by cone death leading to blindness is the pathological signature of all forms of
human retinitis pigmentosa (RP). Therapeutic schemes based on intraocular delivery of neuroprotective agents prolong the
lifetime of photoreceptors and have reached the stage of clinical trial. The success of these approaches depends upon
optimization of chronic supply and appropriate combination of factors. Environmental enrichment (EE), a novel
neuroprotective strategy based on enhanced motor, sensory and social stimulation, has already been shown to exert
beneficial effects in animal models of various disorders of the CNS, including Alzheimer and Huntington disease. Here we
report the results of prolonged exposure of rd10 mice, a mutant strain undergoing progressive photoreceptor degeneration
mimicking human RP, to such an enriched environment from birth. By means of microscopy of retinal tissue,
electrophysiological recordings, visual behaviour assessment and molecular analysis, we show that EE considerably
preserves retinal morphology and physiology as well as visual perception over time in rd10 mutant mice. We find that
protective effects of EE are accompanied by increased expression of retinal mRNAs for CNTF and mTOR, both factors known
as instrumental to photoreceptor survival. Compared to other rescue approaches used in similar animal models, EE is highly
effective, minimally invasive and results into a long-lasting retinal protection. These results open novel perspectives of
research pointing to environmental strategies as useful tools to extend photoreceptor survival
Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
We report magnetic and electrical measurements of Nb Josephson junctions with
strongly ferromagnetic barriers of Co, Ni and Ni80Fe20 (Py). All these
materials show multiple oscillations of critical current with barrier thickness
implying repeated 0-pi phase-transitions in the superconducting order
parameter. We show in particular that the Co barrier devices can be accurately
modelled using existing clean limit theories and so that, despite the high
exchange energy (309 meV), the large IcRN value in the pi-state means Co
barriers are ideally suited to the practical development of superconducting
pi-shift devices.Comment: 4 pages 3 figures 1 table. Revised version as accepted for
publication. To appear in Physical Review Letter
Structural analysis of the architecture and in situ localization of the main S-layer complex in Deinococcus radiodurans
Bacterial surface layers are paracrystalline assemblies of proteins that provide the first line of defense against environmental shocks. Here, we report the 3D structure, in situ localization, and orientation of the S-layer deinoxanthin-binding complex (SDBC), a hetero-oligomeric assembly of proteins that in Deinococcus radiodurans represents the main S-layer unit. The SDBC is resolved at 11-Ã… resolution by single-particle analysis, while its in situ localization is determined by cryo-electron crystallography on intact cell-wall fragments leading to a projection map at 4.5-Ã… resolution. The SDBC exhibits a triangular base with three comma-shaped pores, and a stalk departing orthogonally from the center of the base and oriented toward the intracellular space. Combining state-of-the-art techniques, results show the organization of this S-layer and its connection within the underlying membranes, demonstrating the potential for applications from nanotechnologies to medicine
Myriocin Effect on Tvrm4 Retina, an Autosomal Dominant Pattern of Retinitis Pigmentosa
Tvrm4 mice, a model of autosomal dominant retinitis pigmentosa (RP), carry a mutation of Rhodopsin gene that can be activated by brief exposure to very intense light. Here, we test the possibility of an anatomical, metabolic, and functional recovery by delivering to degenerating Tvrm4 animals, Myriocin, an inhibitor of ceramide de novo synthesis previously shown to effectively slow down retinal degeneration in rd10 mutants (Strettoi et al., 2010; Piano et al., 2013). Different routes and durations of Myriocin administration were attempted by using either single intravitreal (i.v.) or long-term, repeated intraperitoneal (i.p.) injections. The retinal function of treated and control animals was tested by ERG recordings. Retinas from ERG-recorded animals were studied histologically to reveal the extent of photoreceptor death. A correlation was observed between Myriocin administration, lowering of retinal ceramides, and preservation of ERG responses in i.v. injected cases. Noticeably, the i.p. treatment with Myriocin decreased the extension of the retinal-degenerating area, preserved the ERG response, and correlated with decreased levels of biochemical indicators of retinal oxidative damage. The results obtained in this study confirm the efficacy of Myriocin in slowing down retinal degeneration in genetic models of RP independently of the underlying mutation responsible for the disease, likely targeting ceramide-dependent, downstream pathways. Alleviation of retinal oxidative stress upon Myriocin treatment suggests that this molecule, or yet unidentified metabolites, act on cellular detoxification systems supporting cell survival. Altogether, the pharmacological approach chosen here meets the necessary pre-requisites for translation into human therapy to slow down RP
Chlamydia pneumoniae in asymptomatic carotid atherosclerosis.
We evaluated, in 415 patients with asymptomatic carotid atherosclerosis: (i) the prevalence of C. pneumoniae DNA in atherosclerotic carotid plaques and peripheral blood mononuclear cells (PBMC); (i..
AGILE Observations of the Gravitational Wave Event GW150914
We report the results of an extensive search in the AGILE data for a
gamma-ray counterpart of the LIGO gravitational wave event GW150914. Currently
in spinning mode, AGILE has the potential of covering with its gamma-ray
instrument 80 % of the sky more than 100 times a day. It turns out that AGILE
came within a minute from the event time of observing the accessible GW150914
localization region. Interestingly, the gamma-ray detector exposed about 65 %
of this region during the 100 s time intervals centered at -100 s and +300 s
from the event time. We determine a 2-sigma flux upper limit in the band 50 MeV
- 10 GeV, obtained
about 300 s after the event. The timing of this measurement is the fastest ever
obtained for GW150914, and significantly constrains the electromagnetic
emission of a possible high-energy counterpart. We also carried out a search
for a gamma-ray precursor and delayed emission over timescales ranging from
minutes to days: in particular, we obtained an optimal exposure during the
interval -150 / -30 s. In all these observations, we do not detect a
significant signal associated with GW150914. We do not reveal the weak
transient source reported by Fermi-GBM 0.4 s after the event time. However,
even though a gamma-ray counterpart of the GW150914 event was not detected, the
prospects for future AGILE observations of gravitational wave sources are
decidedly promising.Comment: 20 pages, 6 figures. Submitted to the Astrophysical Journal Letters
on April 1, 201
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