1,401 research outputs found
Cell-type specific plasticity at intrapallidal synapses in a mouse model of Parkinson's Disease
The cell types that comprise neural networks are critical in determining their function.
Within the globus pallidus externa (GPe), a nucleus of the basal ganglia implicated in
Parkinsonism, several neuronal subpopulations have been described genetically and
anatomically, but functional and physiological studies have been limited. This study examines
the previously undescribed collateral connections between two key cell types in the GPe, defined
by the genetic expression of parvalbumin (PV) or LIM homeobox 6 (Lhx6). Further investigation
of this network in a mouse model of Parkinson’s Disease reveals a selective weakening of
synaptic input from PV to Lhx6 neurons following dopamine lesions. This study builds on recent
literature elucidating the roles of specific GPe cell types to basal ganglia function in health and
disease
Pediatric Hepatology: A three-year experience with pediatric liver transplantation with cyclosporine and steroids
El Roque de Los Muchachos Site Characteristics. III. Analysis of Atmospheric Dust and Aerosol Extinction
Canary Islands are normally interested by dominant North-East winds that, in
some meteorological conditions, can transport sand at high altitude from the
Sahara desert. The dust may affect the efficiency of the telescopes and
decreases the transparency of the sky. In order to maximize the scientific
return of the telescopes located at the ORM, we present an analysis of the
atmospheric dust content and its effects on astronomical observations. B, V and
I dust aerosol astronomical extinction are derived. Using a 5 years series
database of data taken from the four channel TNG dust monitor, we compute a
mean hourly and daily values of the dust content. We have detected particles
having size 0.3, 0.5, 1.0 and 5.0 um. Using a power law we have derived the
content of 10.0 um particles. We found a typical local dust concentration
ranging from 3x10^6 particles per cubic meter at 0.3 um, to 10^3 at 5.0 um and
10 at 10.0 um, increasing up to 3 order of magnitudes during the dust storms,
with a relative higher increase of 1.0, 5.0 and 10.0 um particles. The number
of local dust storm events is the same in winter- and summertime, but, the
average background and storm-related increases in the dust concentration in
summer are significantly higher than in winter. In a uniform approximation,
during the dust storms, an average height of the dust layer of 2.5 km above the
telescope is inferred. During the sand storms La Palma Island is affected by an
almost uniform layer extending up to 5 km above the sea level, down, at least
the height of the telescope. The visible extinction is dominated by particles
at 1.0, 5.0 and 10.0 um. In agreement with the results from Carlsberg Automatic
Meridian Circle (CAMC) we find a typical extinction during dust storms of about
0.2 mag/airmass.Comment: Accepted for publication in A&A. 9 pages, 11 figures. This work is
the continuation of a series of papers concerning a detailed study of the
Astroclimatology at ORM. The two previous papers (both Lombardi et al.) have
reference PASP.2006.118.1198-1204 and PASP.2007.119.292-30
El Roque de Los Muchachos Site Characteristics. II. Analysis of Wind, Relative Humidity and Air Pressure
In this paper we present an analysis of wind speed, wind direction, relative
humidity and air pressure taken at TNG, CAMC and NOT at Observatorio del Roque
de Los Muchachos, in the Canary Islands. Data are compared in order to check
local variations and both long term and short term trends of the microclimate.
Furthermore, influence of wind speed on the astronomical seeing is estimated to
the aim to better understand the influence of wide scale parameters on local
meteorological data. The three telescopes show different prevailing wind
direction, wind speed, relative humidity and air pressure confirming
differences in local microclimate. We found that seeing deteriorates when wind
speed is lower than 3.3 m/s. Comparison in terms of wind speed and high
relative humidity (> 90%) shows that TNG seems to have optimal observational
conditions with respect to CAMC and NOT. Air pressure analysis shows that ORM
is dominated by high pressure. Short time variations of pressure anticipate
temperature variations tipically by 2-3 hours, this property vanishes in time
scales higher than some hours and disappear in longer time scales.Comment: 10 pages, 9 figures, accepted for publication in PAS
Orthotopic liver transplantation in children. Two-year experience with 47 patients
During a 24-month period (May 1981 to May 1983), 47 pediatric patients (ranging in age from 7 months to 18 years) underwent orthotopic liver transplantation using cyclosporine and prednisone. Major indications were biliary atresia/hypoplasia, and metabolic liver disease. Thirty-two of 138 patients evaluated for the procedure died prior to transplantation. Thirty patients are alive from 6 to 29 months later including 7/15 patients who required retransplantation. Twenty-one of 32 patients are alive at 1 year following initial transplantation. All 30 survivors are clinically well and living at home; only one has an abnormal bilirubin level. Serious, life-threatening medical and surgical complications were common during the early months following transplantation. With one exception, deaths and major rejection episodes occurred early (before 120 days). All survivors are relieved of the stigmata of chronic liver disease, and many have demonstrated catch-up growth. Liver transplantation is an effective treatment for end-stage pediatric liver disease
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