1,644 research outputs found
Diffuse Ionized Gas in the Milky Way Disk
We analyze the diffuse ionized gas (DIG) in the first Galactic quadrant from
l=18deg to 40deg using radio recombination line (RRL) data from the Green Bank
Telescope. These data allow us to distinguish DIG emission from HII region
emission and thus study the diffuse gas essentially unaffected by confusion
from discrete sources. We find that the DIG has two dominant velocity
components, one centered around 100km/s associated with the luminous HII region
W43, and the other centered around 45km/s not associated with any large HII
region. Our analysis suggests that the two velocity components near W43 may be
caused by non-circular streaming motions originating near the end of the
Galactic bar. At lower Galactic longitudes, the two velocities may instead
arise from gas at two distinct distances from the Sun, with the most likely
distances being ~6kpc for the 100km/s component and ~12kpc for the 45km/s
component. We show that the intensity of diffuse Spitzer GLIMPSE 8.0um emission
caused by excitation of polyaromatic hydrocarbons (PAHs) is correlated with
both the locations of discrete HII regions and the intensity of the RRL
emission from the DIG. This implies that the soft ultra-violet photons
responsible for creating the infrared emission have a similar origin as the
harder ultra-violet photons required for the RRL emission. The 8.0um emission
increases with RRL intensity but flattens out for directions with the most
intense RRL emission, suggesting that PAHs are partially destroyed by the
energetic radiation field at these locations.Comment: Accepted for publication in ApJ (16 pages, 11 figures, 2 tables
HII Region Ionization of the Interstellar Medium: A Case Study of NGC 7538
Using data from the Green Bank Telescope, we analyze the radio continuum
(free-free) and radio recombination line (RRL) emission of the compact HII
region NGC 7538 (Sharpless 158). We detect extended radio continuum and
hydrogen RRL emission beyond the photodissociation region (PDR) toward the
north and east, but a sharp decrease in emission toward the south and west.
This indicates that a non-uniform PDR morphology is affecting the amount of
radiation "leaking" through the PDR. The strongest carbon RRL emission is found
in the western PDR that appears to be dense. We compute a leaking fraction % of the radio continuum emission measured in the plane of the sky
which represents a lower limit when accounting for the three-dimensional
geometry of the region. We detect an average
abundance ratio by number of inside the HII region and a
decrease in this ratio with increasing distance from the region beyond the PDR.
Using Herschel Space Observatory data, we show that small dust temperature
enhancements to the north and east of NGC 7538 coincide with extended radio
emission, but that the dust temperature enhancements are mostly contained
within a second PDR to the east. Unlike the giant HII region W43, the radiation
leaking from NGC 7538 seems to only affect the local ambient medium. This
suggests that giant HII regions may have a large effect in maintaining the
ionization of the interstellar medium.Comment: Accepted for publication in ApJ (15 pages, 10 figures, 2 tables
Diffuse Ionized Gas in the Milky Way Disk
We analyze the diffuse ionized gas (DIG) in the first Galactic quadrant from
l=18deg to 40deg using radio recombination line (RRL) data from the Green Bank
Telescope. These data allow us to distinguish DIG emission from HII region
emission and thus study the diffuse gas essentially unaffected by confusion
from discrete sources. We find that the DIG has two dominant velocity
components, one centered around 100km/s associated with the luminous HII region
W43, and the other centered around 45km/s not associated with any large HII
region. Our analysis suggests that the two velocity components near W43 may be
caused by non-circular streaming motions originating near the end of the
Galactic bar. At lower Galactic longitudes, the two velocities may instead
arise from gas at two distinct distances from the Sun, with the most likely
distances being ~6kpc for the 100km/s component and ~12kpc for the 45km/s
component. We show that the intensity of diffuse Spitzer GLIMPSE 8.0um emission
caused by excitation of polyaromatic hydrocarbons (PAHs) is correlated with
both the locations of discrete HII regions and the intensity of the RRL
emission from the DIG. This implies that the soft ultra-violet photons
responsible for creating the infrared emission have a similar origin as the
harder ultra-violet photons required for the RRL emission. The 8.0um emission
increases with RRL intensity but flattens out for directions with the most
intense RRL emission, suggesting that PAHs are partially destroyed by the
energetic radiation field at these locations.Comment: Accepted for publication in ApJ (16 pages, 11 figures, 2 tables
Thoracic involvement in generalised lymphatic anomaly (or lymphangiomatosis)
Generalised lymphatic anomaly (GLA), also known as lymphangiomatosis, is a rare disease caused by congenital abnormalities of lymphatic development. It usually presents in childhood but can also be diagnosed in adults. GLA encompasses a wide spectrum of clinical manifestations ranging from singleorgan involvement to generalised disease. Given the rarity of the disease, most of the information regarding it comes from case reports. To date, no clinical trials concerning treatment are available. This review focuses on thoracic GLA and summarises possible diagnostic and therapeutic approaches
Increased adrenal steroid secretion in response to CRF in women with hypothalamic amenorrhea
Objectie: To evaluate adrenal steroid hormone secretion in response to corticotropin-releasing factor (CRF) or to adrenocorticotropin
hormone in women with hypothalamic amenorrhea. Design: Controlled clinical study. Setting: Department of
Reproductive Medicine and Child Development, Section of Gynecology and Obstetrics, University of Pisa, Italy. Patient(s):
Fifteen women with hypothalamic amenorrhea were enrolled in the study. Eight normal cycling women were used as control
group. Interention(s): Blood samples were collected before and after an injection of ovine CRF (0.1 g/kg iv bolus) or after
synthetic ACTH (0.25 mg iv). Main outcome measure(s): Plasma levels of ACTH, 17-hydroxypregnenolone (17OHPe), progesterone
(P), dehydroepiandrosterone (DHEA), 17-hydroxyprogesterone (17OHP), cortisol (F), 11-deoxycortisol (S) and androstenedione
(A). Result(s): Basal plasma concentrations of ACTH, cortisol, 11-deoxycortisol, DHEA and 17OHPe were significantly
higher in patients than in controls, whereas plasma levels of progesterone and 17-OHP were significantly lower in patients than
in controls. In amenorrheic women the ratio of 17-OHPe/DHEA, of 17-OHPe/17-OHP and of 11-deoxycortisol/cortisol were
significantly higher than in controls, while a significant reduction in the ratio of 17-OHP/androstenedione, of 17-OHP/11-deoxycortisol
was obtained. In response to corticotropin-releasing factor test, plasma levels of ACTH, cortisol, 17-OHP, 11-deoxycortisol,
DHEA and androstenedione were significantly lower in patients than in controls. In response to adrenocorticotropin
hormone, plasma levels of 17-OHP, androstenedione and androstenedione/cortisol were significantly higher in patients than in
controls. Conclusions: Patients suffering for hypothalamic amenorrhea showed an increased activation of hypothalamus-pituitaryadrenal
(HPA) axis, as shown by the higher basal levels and by augmented adrenal hormone response to corticotropin-releasing
factor administration. These data suggest a possible derangement of adrenal androgen enzymatic pathway
STEM materials: a new frontier for an intelligent sustainable world
Materials are addressed as possible enablers for solutions to many global societal challenges. A foresight exercise has been conducted to identify research paths to design, with a new approach, a generation of materials which can provide multi-functionalities. These material systems have been named ???stem???, in analogy to living cells where a base of primitive units can be designed and assembled for self-reacting to external inputs. These materials will embed a concept of ???internet in things???, where their processing capacity will enable the systems to interact with the environment and express diverse functionalities. Stem materials do not exist yet, but many clues from diferent theoretical and experimental results suggest they can be developed, and because living organisms exist. This article aims at launching this new approach and promoting the structuring of a multi-disciplinary community to fll the research gaps
Routine e improvvisazione nelle strutture ricettive all’aria aperta italiane
Il testo si occupa dell'organizzazione e del paesaggio delle strutture ricettive all'aria aperta. Affronta lo sviluppo e l'evoluzione del turismo all'aria aperta nel corso degli ultimi due secoli per arrivare alla definizione dell'attualità dei camping e dei villaggi turistici. Il testo affronta la complessità del rapporto tra esperienza del luogo e atopicità della strutturazione dell'offerta turistica. Il paesaggio del turismo open air coniuga esigenze di routine, legate alla ripetitività dell'organizzazione delle strutture, e all'improvvisazione e libertà della esperienza vacanza. L'articolo evidenzia la necessità di una riflessione sui temi dell'architettura e della progettazione degli spazi aperti per creare le condizioni di sviluppo di nuove forme di paesaggio del turismo all'aria aperta
Serum Levels of Tryptophan, 5-Hydroxytryptophan and Serotonin in Patients Affected with Different Forms of Amenorrhea
Tryptophan (Trp) is present in the serum, partly bound to albumine and in the free form. The unbound portion of circulating tryptophan has the property of crossing the hematoencephalic barrier and being converted within the brain into serotonin (5-HT) through the enzymatic processes of hydroxylation and decarboxylation. The serotoninergic system plays an important role in neuroendocrine control of reproductive hormone secretion, and in particular, it may influence GnRH pulsatility, a function essential for reproductive processes. In this study, we analysed serum levels of tryptophan, serotonin and 5-hydroxytryptophan (5-HTP) in women with three different forms of amenorrhea: 16 patients were diagnosed with anorexia nervosa, 60 patients with functional hypothalamic amenorrhea, and 14 patients with hyperprolactinemia. Data were compared with those of a group of 25 healthy women. Serum Trp levels were significantly (P ≤ 0.05) lower in the anorexic (11.64 ± 0.53 μg/ml, mean ± S.E.) than in the control (12.98 ± 0.37 μg/ml) groups. In addition, in the anorexic group a statistical dispersion of Trp values was shown indicating a bimodal data distribution suggesting the existence of two different subgroups of patients. Regarding 5-HTP, an increase of its serum level was observed in all the groups with amenorrhea with the highest value in hyperprolactinemic patients. On the contrary, no statistical differences in serum 5-HT levels among the four analyzed groups were observed
- …