743 research outputs found
Spectroscopic Classification of Post-AGB Candidates: (Searching for Proto-Planetary Nebulae)
We have determined the spectral classification of approximately 50 candidates for post-AGB, proto-planetary nebula (PPN) objects. The candidates were chosen based on their infrared excesses as seen in the IRAS data. The spectra are of low-resolution (R~550) and were obtained with the Kitt Peak National Observatory 2.1-m and the Steward Observatory 2.3-m telescopes. Spectroscopy has permitted us to discriminate between PPNe and other objects with dust, such as pre-main sequence stars and planetary nebulae. Most of the objects appear to be PPNe, ranging in spectral type from K to B, with some of the hotter ones showing hydrogen emission lines. A number of the objects have published classifications, which we list for comparison. Some were previously classified as PPNe but a few are new identifications. We are also carrying on a photometric monitoring program of many of these objects to study light variability. This research is supported by the NSF (most recently AST-1413660)
Xylem plasticity in Pinus pinaster and Quercus ilex growing at sites with different water availability in the Mediterranean region: relations between Intra-Annual Density Fluctuations and environmental conditions.
Fluctuations in climatic conditions during the growing season are recorded in Mediterranean tree-rings and often result in intra-annual density fluctuations (IADFs). Dendroecology and quantitative wood anatomy analyses were used to characterize the relations between the variability of IADF traits and climatic drivers in Pinus pinaster Aiton and Quercus ilex L. growing at sites with different water availability on the Elba island in Central Italy. Our results showed that both species present high xylem plasticity resulting in the formation of L-type IADFs (L-IADFs), consisting of earlywood-like cells in latewood. The occurrence of such IADFs was linked to rain events following periods of summer drought. The formation of L-IADFs in both species increased the hydraulic conductivity late in the growing season, due to their larger lumen area in comparison to "true latewood". The two species expressed greater similarity under arid conditions, as unfavorable climates constrained trait variation. Wood density, measured as the percentage of cell walls over total xylem area, IADF frequency, as well as conduit lumen area and vessel frequency, specifically in the hardwood species, proved to be efficient proxies to encode climate signals recorded in the xylem. The response of these anatomical traits to climatic variations was found to be species- and site-specific
FECAL MICROBIOTA TRANSPLANTATION BEFORE OR AFTER ALLOGENEIC HEMATOPOIETIC TRANSPLANTATION IN PATIENTS WITH HEMATOLOGICAL MALIGNANCIES CARRYING MULTIDRUG-RESISTANCE BACTERIA
Fecal microbiota transplantation is an effective treatment in recurrent Clostridium difficile infection. Promising results to eradicate multidrug-resistant bacteria have also been reported with this procedure, but there are safety concerns in immunocompromised patients. We report results in 10 adult patients colonized with multidrug-resistant bacteria, undergoing fecal microbiota transplantation before (n=4) or after (n=6) allogeneic hematopoietic stem cell transplantation for hematologic malignancies.
Stools were obtained from healthy related or unrelated donors. Fecal material was delivered either by enema or via nasogastric tube. Patients were colonized or had infections from either carbapenemase-producing bacteria (n=8) or vancomycin-resistant enterococci (n=2). The median age at fecal microbiota transplantation was 48 (range 16-64) years. Three patients needed a second transplant from the same donor, due to initial failure of the procedure.
With a median follow-up of 13 (range 4-40) months, decolonization was achieved in seven out of ten patients. In all patients, fecal microbiota transplantation was safe: one patient presented with constipation during the first 5 days after FMT and 2 patients had grade I diarrhea. One case of gut grade III acute graft-versus-host disease occurred after fecal microbiota transplantation. In patients carrying or infected by multidrug-resistant bacteria, fecal microbiota transplantation is an effective and safe decolonization strategy, even in those with hematologic malignancies undergoing hematopoietic stem cell transplantation
Spectroscopic Classification of Post-AGB Candidates: (Searching for Proto-Planetary Nebulae)
We have determined the spectral classification of approximately 50 candidates for post-AGB, proto-planetary nebula (PPN) objects. The candidates were chosen based on their infrared excesses as seen in the IRAS data. The spectra are of low-resolution (R~550) and were obtained with the Kitt Peak National Observatory 2.1-m and the Steward Observatory 2.3-m telescopes. Spectroscopy has permitted us to discriminate between PPNe and other objects with dust, such as pre-main sequence stars and planetary nebulae. Most of the objects appear to be PPNe, ranging in spectral type from K to B, with some of the hotter ones showing hydrogen emission lines. A number of the objects have published classifications, which we list for comparison. Some were previously classified as PPNe but a few are new identifications. We are also carrying on a photometric monitoring program of many of these objects to study light variability. This research is supported by the NSF (most recently AST-1413660)
Evaluation of SCION for User-driven Path Control:a Usability Study
The UPIN (User-driven Path verification and control in Inter-domain Networks) project aims to implement a way for users of a network to control how their data is traversing it. In this paper we investigate the possibilities and limitations of SCION for user-driven path control. Exploring several aspects of the performance of a SCION network allows us to define the most efficient path to assign to a user, following specific requests. We extensively analyze multiple paths, specifically focusing on latency, bandwidth and data loss, in SCIONLab, an experimental testbed and implementation of a SCION network. We gather data on these paths and store it in a database, that we then query to select the best path to give to a user to reach a destination, following their request on performance or devices to exclude for geographical or sovereignty reasons. Results indicate our software is a viable option to offer users many paths to choose from, following a series of requests, and therefore perform user-driven path control in a SCION network.</p
La tradizione religiosa degli Ainu e la rivitalizzazione di antichi rituali
The Ainu are a group of populations settled on the Kamchatka Peninsula, on the island of Sakhalin, in the Kurils and in Hokkaidō. I will examine the Ainu of the island of Hokkaidō. During the Tokugawa (1603-1868) and Meiji (1868-1912) periods, the Japanese imposed reforms and forced assimilation, depriving them of their cultural heritage. Initially labeled as "last", over time the Ainu have been invited to folklore along with a slow restitution of their cultural tradition, albeit with some compromise. In this way, tourist centers have most likely become the main gateways to a universe still pervaded by mystery. This article explores the changes in religious tradition, starting with the cosmogonic world, passing through ceremonies in their most traditional form, to examining how such ceremonials have been transformed for tourism purposes.Los Ainu son un grupo de poblaciones asentadas en la península de Kamchatka, en la isla de Sakhalin, en las Kuriles y en Hokkaidō. Examinaré a los Ainu de la isla de Hokkaidō. Durante los períodos Tokugawa (1603-1868) y Meiji (1868-1912), los japoneses impusieron reformas y forzaron su asimilación, despojándolos de su herencia cultural. Inicialmente etiquetados como "últimos", con el tiempo los Ainu han sido invitados al folclore junto con una lenta restitución de su tradición cultural, aunque con cierto compromiso. De esta forma, los centros turísticos se han convertido muy probablemente en las principales puertas de entrada a un universo todavía impregnado de misterio. Este artículo explora los cambios en la tradición religiosa, comenzando por el mundo cosmogónico, pasando por las ceremonias en su forma más tradicional, hasta examinar cómo dichas ceremonias se han transformado con fines turísticos
Comparing Methods for the Analysis of δ 13C in Falanghina Grape Must from Different Pedoclimatic Conditions
Agroforestry applications in viticulture are considered a promising strategy to improve vine water status by mitigating the threats of increasing drought due to climate change. The analysis of δ13 C is often used in viticulture to understand vine water use. In this study, the analysis of δ13 C was performed on the must of Falanghina grapevines growing in different pedoclimatic conditions. The aim was to compare the results obtained by the application of two different methodologies, using the whole must or extracted sugars as the matrix. The results showed that the δ13 C values obtained by applying the two methodologies were comparable in all analyzed vineyards independently from the pedoclimatic conditions. Indeed, the proposed method of extraction of the δ13 C on the must as a whole can be both cost-and time-saving for the analysis. This is valuable, considering that the δ13 C of must is becoming more and more used as indicator of vines’ water use. Therefore, the possibility to utilize a simplified method of extraction would enhance the application of the δ13 C at a larger scale to evaluate vine adaptation in the context of climate-change-driven increases in drought
Tree-ring growth and stable isotopes (13C and 15N) detect effects of wildfires on tree physiological processes in Pinus sylvestris L
Forest fires may alter the physiological and growth processes of trees by causing stress in trees and modifying the availability of soil nutrient. We investigated if, after a high-severity fire, changes in tree-ring growth can be observed, as well as changes in the nitrogen and carbon isotope composition of tree rings of surviving trees. Two wildfires that occurred in Pinus sylvestris L. stands in Northern Italy, one at the beginning and one at the end of the vegetative season, were chosen as the focus of this study. After the fires, the surviving trees showed growth suppression with very narrow tree rings or locally absent rings. The carbon isotope ratio was more negative in tree rings formed in the 5years following fire, indicating better water supply in a situation of less competition. The nitrogen isotope ratio followed opposite trends in the two wildfire stands. In trees cored in the stand where the fire happened at the beginning of the vegetative season, there was no change in the nitrogen isotope ratio, whereas in samples collected in the other fire site, higher nitrogen isotope ratios were observed in the tree rings formed after the fire, reflecting changes in the soil nitrogen supply. Modifications in the growth and isotope composition of the fire-stressed trees disappeared from 6 to 10years after the fire. By studying trees before and after fire, we were able to show that fire affects not only the growth of surviving trees, but also their physiological processe
Neuroendocrine effects of carnitines on reproductive impairments
Carnitines are quaternary amines involved in various cellular processes such as fatty acid uptake, β‐oxidation and glucose metabolism regulation. Due to their neurotrophic activities, their integrative use has been studied in several different physio‐pathological conditions such as anorexia nervosa, chronic fatigue, vascular diseases, Alzheimer’s disease and male infertility. Being metabol-ically active, carnitines have also been proposed to treat reproductive impairment such as functional hypothalamic amenorrhea (FHA) and polycystic ovary syndrome (PCOS) since they improve both hormonal and metabolic parameters modulating the neuroendocrine impairments of FHA. Moreo-ver, they are capable of improving the lipid profile and the insulin sensitivity in patients with PCOS
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