539 research outputs found
City, Nature, Culture. New way of Living Sociability (the Case of Reggio Calabria)
Abstract The paper tackles the problems of our modern political society related to city, nature and culture. The policies concerning such specific sectors, if designed in a coordinated and coherent way, are capable of creating an important development model. The case of Reggio Calabria, metropolitan city, is exemplary of this model. The specific characteristics of Reggio Calabria bring out the urgent need to rethink urbanization, together with nature and culture and thus change the very idea of cit
Synthetic spectra of H Balmer and HeI absorption lines. I: Stellar library
We present a grid of synthetic profiles of stellar H Balmer and HeI lines at
optical wavelengths with a sampling of 0.3 A. The grid spans a range of
effective temperature 4000 K < Teff < 50000 K, and gravity 0.0 < log g < 5.0 at
solar metallicity. For Teff > 25000 K, NLTE stellar atmosphere models are
computed using the code TLUSTY (Hubeny 1988). For cooler stars, Kurucz (1993)
LTE models are used to compute thesynthetic spectra. The grid includes the
profiles of the high-order hydrogen Balmer series and HeI lines for effective
temperatures and gravities that have not been previously synthesized. The
behavior of H8 to H13 and HeI 3819 with effective temperature and gravity is
very similar to that of the lower terms of the series (e.g. Hb) and the other
HeI lines at longer wavelengths; therefore, they are suited for the
determination of the atmospheric parameters of stars. These lines are
potentially important to make predictions for these stellar absorption features
in galaxies with active star formation. Evolutionary synthesis models of these
lines for starburst and post-starburst galaxies are presented in a companion
paper. The full set of the synthetic stellar spectra is available for retrieval
at our website http://www.iaa.es/ae/e2.html and
http://www.stsci.edu/science/starburst/ or on request from the authors at
[email protected]: To be published in ApJS. 28 pages and 12 figure
DESIGN AND SYNTHESIS OF NATURAL COMPOUNDS ANALOGUES WITH CYTOTOXIC ACTIVITY
This Ph.D. work was carried out as a part of project focusing on the search of new naturally-derived topoisomerase I inhibitors as potential antitumor compounds. Topoisomerase I is the target of anticancer drug campthotecin (CPT). First generation analogues of CPT are already approved as anticancer agents in human therapy, and several second and third generation derivatives are well advanced in clinical trials. Nevertheless, identification of new campthotecins or alternative molecular scaffolds endowed with similar properties is highly desirable because CPT derivatives were shown to be worth of improvement, above all for the unstable \uf061-hydroxylactone moiety. First, new CPT derivatives were planned and synthesized, in an effort to decrease the toxicity and improve the E ring stability of the natural alkaloid. The study was undertaken to explore new structural changes at the E ring, while keeping a lactone moiety in this portion of the molecule. Thus, new analogues with an inverted lactone ring were designed and synthesized. The compounds retained a good cytotoxic activity on human non-small cancer cells H460. At the same time, the search of new scaffolds showing topoisomerase I inhibitory activity was developed. Attention focused on a new class of marine alkaloids called lamellarins that have been recently studied as Topo I inhibitors. In this Ph.D. work new lamellarin analogues were designed. Molecular models of the ternary complex formed between the DNA-Topo I ensemble and the new derivatives were built, and allowed to optimize the scaffold structure. Thus the synthesis of a number of new compounds endowed with cytotoxicity in the low micromolar range was accomplished
Synthetic spectra of H Balmer and HeI absorption lines. II: Evolutionary synthesis models for starburst and post-starburst galaxies
We present evolutionary stellar population synthesis models to predict the
spectrum of a single-metallicity stellar population, with a spectral sampling
of 0.3 A in five spectral regions between 3700 and 5000 A. The models, which
are optimized for galaxies with active star formation, synthesize the profiles
of the hydrogen Balmer series (Hb, Hg, Hd, H8, H9, H10, H11, H12 and H13) and
the neutral helium absorption lines (HeI 4922, HeI 4471, HeI 4388, HeI 4144,
HeI 4121, HeI 4026, HeI 4009 and HeI 3819) for a burst with an age ranging from
1 to 1000 Myr, and different assumptions about the stellar initial mass
function. Continuous star formation models lasting for 1 Gyr are also
presented. The input stellar library includes NLTE absorption profiles for
stars hotter than 25000 K and LTE profiles for lower temperatures. The
temperature and gravity coverage is 4000 K <Teff< 50000 K and 0.0< log g$< 5.0,
respectively.
The models can be used to date starburst and post-starburst galaxies until 1
Gyr. They have been tested on data for clusters in the LMC, the super-star
cluster B in the starburst galaxy NGC 1569, the nucleus of the dwarf elliptical
NGC 205 and a luminous "E+A" galaxy. The full data set is available for
retrieval at http://www.iaa.es/ae/e2.html and at
http://www.stsci.edu/science/starburst/, or on request from the authors at
[email protected]: To be published in ApJS. 48 pages and 20 figure
Translation, Identity, Society: The European Case of Cultural Multiplicity
The article discusses the philosophy of the translation of Domenico Jervolino applying it to the case of the European Union. The models of multi-culturalism and interculture are implemented within the EU
Conservative treatment for cystic duct stenosis in a child.
Introduction. Few cases of common bile duct stenosis have been reported in the literature, and observations of strictures in the cystic duct are even more rare. Surgical cholecystectomy is the treatment needed in most cases of gallbladder hydrops. This paper describes the diagnosis and successful medical treatment of a rare pediatric case of cystic duct stenosis and gallbladder hydrops. Case Report. A formerly healthy one-year-old girl was admitted with colicky abdominal pain. Blood tests were normal, except for an increase in transaminases. Abdominal ultrasound excluded intestinal intussusception and identified a distended gallbladder with biliary sludge. MR cholangiography revealed a dilated gallbladder containing bile sediment and no detectable cystic duct, while the rest of the intra- and extrahepatic biliary tree and hepatic parenchyma were normal. This evidence was consistent with gallbladder hydrops associated with cystic duct stenosis. The baby was treated with i.v. hydration, corticosteroids, antibiotics, and ursodeoxycholic acid. Her general condition rapidly improved, with no further episodes of abdominal pain and normalization of liver enzymes. This allowed to avoid cholecystectomy, and the child is well 1.5 years after diagnosis. Conclusions. Although cholecystectomy is usually necessary in case of gallbladder hydrops, our experience suggests that surgical procedures can be avoided when the distension is caused by a cystic duct stenosis
Spectrophotometric investigations of Blue Compact Dwarf Galaxies: Markarian 35
We present results from a detailed spectrophotometric analysis of the blue
compact dwarf galaxy Mrk 35 (Haro 3), based on deep optical (B,V,R,I) and
near-IR (J,H,K) imaging, Halpha narrow-band observations and long-slit
spectroscopy. The optical emission of the galaxy is dominated by a central
young starburst, with a bar-like shape, while an underlying component of stars,
with elliptical isophotes and red colors, extends more than 4 kpc from the
galaxy center. High resolution Halpha and color maps allow us to identify the
star-forming regions, to spatially discriminate them from the older stars, and
to recognize several dust patches. We derive colors and Halpha parameters for
all the identified star-forming knots. Observables derived for each knot are
corrected for the contribution of the underlying older stellar population, the
contribution by emission lines, and from interstellar extinction, and compared
with evolutionary synthesis models. We find that the contributions of these
three factors are by no means negligible and that they significantly vary
across the galaxy. Therefore, careful quantification and subtraction of
emission lines, galaxy host contribution, and interstellar reddening at every
galaxy position, are essential to derive the properties of the young stars in
BCDs. We find that we can reproduce the colors of all the knots with an
instantaneous burst of star formation and the Salpeter initial mass function
with an upper mass limit of 100 M_solar. In all cases the knots are just a few
Myr old. The underlying population of stars has colors consistent with being
several Gyr old.Comment: 21 pages, 13 figures. Accepted for publication in ApJ, tentatively
scheduled for the ApJ November 1, 2007 v669n1 issu
Spectrophotometric Observations of Blue Compact Dwarf Galaxies: Mrk 370
We present results from a detailed spectrophotometric analysis of the blue
compact dwarf galaxy (BCD) Mrk 370, based on deep UBVRI broad-band and Halpha
narrow-band observations, and long-slit and two-dimensional spectroscopy of its
brightest knots. The spectroscopic data are used to derive the internal
extinction, and to compute metallicities, electronic density and temperature in
the knots. By subtracting the contribution of the underlying older stellar
population, modeled by an exponential function, removing the contribution from
emission lines, and correcting for extinction, we can measure the true colors
of the young star-forming knots. We show that the colors obtained this way
differ significantly from those derived without the above corrections, and lead
to different estimates of the ages and star-forming history of the knots. Using
predictions of evolutionary synthesis models, we estimate the ages of both the
starburst regions and the underlying stellar component. We found that we can
reproduce the colors of all the knots with an instantaneous burst of star
formation and the Salpeter initial mass function with an upper mass limit of
100 solar masses. The resulting ages range between 3 and 6 Myrs. The colors of
the low surface brightness component are consistent with ages larger than 5
Gyr. The kinematic results suggest ordered motion around the major axis of the
galaxy.Comment: 26 pages with 14 figures; accepted for publication in Ap
Autologous transplantation of amniotic fluid-derived mesenchymal stem cells into sheep fetuses
Long-term engraftment and phenotype correction has been difficult to achieve in humans after in utero stem cell transplantation mainly because of allogeneic rejection. Autologous cells could be obtained during gestation from the amniotic fluid with minimal risk for the fetus and the mother. Using a sheep model, we explored the possibility of using amniotic fluid mesenchymal stem cells (AFMSCs) for autologous in utero stem cell/gene therapy. We collected amniotic fluid (AF) under ultrasound-guided amniocentesis in early gestation pregnant sheep (n = 9, 58 days of gestation, term = 145 days). AFMSCs were isolated and expanded in all sampled fetal sheep. Those cells were transduced using an HIV vector encoding enhanced green fluorescent protein (GFP) with 63.2% (range 38.3-96.2%) transduction efficiency rate. After expansion, transduced AFMSCs were injected into the peritoneal cavity of each donor fetal sheep at 76 days under ultrasound guidance. One ewe miscarried twin fetuses after amniocentesis. Intraperitoneal injection was successful in the remaining 7 fetal sheep giving a 78% survival for the full procedure. Tissues were sampled at postmortem examination 2 weeks later. PCR analysis detected GFP-positive cells in fetal tissues including liver, heart, placenta, membrane, umbilical cord, adrenal gland, and muscle. GFP protein was detected in these tissues by Western blotting and further confirmed by cytofluorimetric and immunofluorescence analyses. This is the first demonstration of autologous stem cell transplantation in the fetus using AFMSCs. Autologous cells derived from AF showed widespread organ migration and could offer an alternative way to ameliorate prenatal congenital diseas
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