953 resultados para Open clusters and associations: general


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper discusses 226 earlier Neolithic pits found at Kilverstone in Norfolk. In particular, it focuses on the dynamics involved in the site's creation, investigating what had happened to the material found in the pits prior to deposition, and exploring the material connections (refitting sherds and flints) across the site. As a result of these material insights, it proved possible to shed important light on the character of that place in particular, and on the temporality of Neolithic deposition and occupation in general.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective: The objective was to report a case of olfactory reference syndrome (ORS) with several co-occurring disorders and to discuss ORS differential diagnoses, diagnostic criteria and classification.Method: Case report.Results: A 37-year-old married woman presented overvalued ideas of having bad breath since adolescence. Shemet current diagnostic criteria for social anxiety disorder, specific phobia, obsessive-compulsive disorder, generalized anxiety disorder, body dysmorphic disorder and major depressive disorder. ORS similarities and differences with some related disorders are discussed.Conclusion: Further studies regarding symptoms, biomarkers and outcomes are needed to fully disentangle ORS from existing depressive, anxiety and obsessive-compulsive spectrum disorders. (C) 2014 Elsevier Inc. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The project investigated the presentation of crime in the Lithuanian media and its possible impact on the general public's understanding of crime-related problems in society. Dobryninas concentrated on three main aspects of this problem: the development of the image of crime in the Lithuanian press and television, journalists' principles in presenting crime-related information, and the public attitude to the presentation of crime in the media. A content analysis of national newspapers from the period of 1992-1997 showed not only increasing interest in crime problems, but also the distorted nature of the image of crime in the media. In-depth interviews with Lithuanian journalists demonstrated that they understood their role in presenting crime-related information firstly as providing information oriented to high public demand, although at the same time they did not deny the commercial and entertainment aspects of crime reporting. Readership and audience research illustrated the clear influence of the media on the public understanding of crime problems in society. However, the virtual image of crime did not greatly affect the system of values and beliefs of Lithuanians, nor did it challenge their insistence that problems of crime could and should be managed within the framework of a civil and open society.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Earth observations (EO) represent a growing and valuable resource for many scientific, research and practical applications carried out by users around the world. Access to EO data for some applications or activities, like climate change research or emergency response activities, becomes indispensable for their success. However, often EO data or products made of them are (or are claimed to be) subject to intellectual property law protection and are licensed under specific conditions regarding access and use. Restrictive conditions on data use can be prohibitive for further work with the data. Global Earth Observation System of Systems (GEOSS) is an initiative led by the Group on Earth Observations (GEO) with the aim to provide coordinated, comprehensive, and sustained EO and information for making informed decisions in various areas beneficial to societies, their functioning and development. It seeks to share data with users world-wide with the fewest possible restrictions on their use by implementing GEOSS Data Sharing Principles adopted by GEO. The Principles proclaim full and open exchange of data shared within GEOSS, while recognising relevant international instruments and national policies and legislation through which restrictions on the use of data may be imposed.The paper focuses on the issue of the legal interoperability of data that are shared with varying restrictions on use with the aim to explore the options of making data interoperable. The main question it addresses is whether the public domain or its equivalents represent the best mechanism to ensure legal interoperability of data. To this end, the paper analyses legal protection regimes and their norms applicable to EO data. Based on the findings, it highlights the existing public law statutory, regulatory, and policy approaches, as well as private law instruments, such as waivers, licenses and contracts, that may be used to place the datasets in the public domain, or otherwise make them publicly available for use and re-use without restrictions. It uses GEOSS and the particular characteristics of it as a system to identify the ways to reconcile the vast possibilities it provides through sharing of data from various sources and jurisdictions on the one hand, and the restrictions on the use of the shared resources on the other. On a more general level the paper seeks to draw attention to the obstacles and potential regulatory solutions for sharing factual or research data for the purposes that go beyond research and education.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As part of a long term effort to understand pre-main sequence Li burning, we have obtained high resolution spectroscopic observations of 14 late type stars (G0-M1) in the young open cluster IC 4665. Most of the stars have Hα filled-in and Li I absorption, as expected for their young age. From the equivalent widths of Hα emission excess (obtained using the spectral subtraction technique) and the the Li i λ6708 feature, we have derived Hα emission fluxes and photospheric Li abundances. The mean Li abundance of IC 4665 solar-type stars is log N(Li) = 3.1; the same as in other young clusters (α Per, Pleiades) and T Tauri stars. Our results support the conclusions from previous works that PMS Li depletion is very small for masses ∼ 1 M_⨀ . Among the IC 4665 late-G and early K-type stars, there is a spread in Li abundances of about one order of magnitude. The Li-poor IC 4665 members have low Hα excess and vsini≤10. Hence, the Li-activity-rotation connection which has been clearly established in the Pleiades also seems to hold in IC 4665. One M-type IC 4665 star that we have observed does not show Li, implying a very efficient Li depletion as observed in α Per stars of the same spectral type. The level of chromospheric activity and Li depletion among the low-mass stars of IC 4665 is similar to that in the Pleiades. In fact, we note that the Li abundance distributions in several young clusters (α Per, Pleiades, IC 2391, IC 4665) and in post T Tauri stars are strikingly similar. This result suggests that Hα emission and Li abundance not well correlated with age for low-mass stars between 20 and 100 Myr old. We argue that a finer age indicator, the ''LL-clock'', would be the luminosity at which the transition between efficient Li depletion and preservation takes place for fully convective objects. The LL-clock could allow in the near future to derive the relative ages of young open clusters, and clarify the study of PMS evolution of cool stars.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"September 1989"--Cover.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Low vitamin D status is common in Europe. The major source of vitamin D in humans is ultraviolet B (UVB)-induced dermal synthesis of cholecalciferol, whereas food sources are believed to play a lesser role. Our objectives were to assess UVB availability (Jm−2) across several European locations ranging from 35° N to 69° N, and compare these UVB data with representative population serum 25-hydroxyvitamin D (25(OH)D) data from Ireland (51–54° N), Iceland (64° N) and Norway (69° N), as exemplars. Vitamin D-effective UVB availability was modelled for nine European countries/regions using a validated UV irradiance model. Standardized serum 25(OH)D data was accessed from the EC-funded ODIN project. The results showed that UVB availability decreased with increasing latitude (from 35° N to 69° N), while all locations exhibited significant seasonal variation in UVB. The UVB data suggested that the duration of vitamin D winters ranged from none (at 35° N) to eight months (at 69° N). The large seasonal fluctuations in serum 25(OH)D in Irish adults was much dampened in Norwegian and Icelandic adults, despite considerably lower UVB availability at these northern latitudes but with much higher vitamin D intakes. In conclusion, increasing the vitamin D intake can ameliorate the impact of low UVB availability on serum 25(OH)D status in Europe.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We simulate currents and concentration profiles generated by Ca2+ release from the endoplasmic reticulum (ER) to the cytosol through IP3 receptor channel clusters. Clusters are described as conducting pores in the lumenal membrane with a diameter from 6 nm to 36 nm. The endoplasmic reticulum is modeled as a disc with a radius of 1–12 mm and an inner height of 28 nm. We adapt the dependence of the currents on the trans Ca2+ concentration (intralumenal) measured in lipid bilayer experiments to the cellular geometry. Simulated currents are compared with signal mass measurements in Xenopus oocytes. We find that release currents depend linearly on the concentration of free Ca2+ in the lumen. The release current is approximately proportional to the square root of the number of open channels in a cluster. Cytosolic concentrations at the location of the cluster range from 25 μM to 170 μM. Concentration increase due to puffs in a distance of a few micrometers from the puff site is found to be in the nanomolar range. Release currents decay biexponentially with timescales of < 1 s and a few seconds. Concentration profiles decay with timescales of 0.125–0.250 s upon termination of release.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This Thesis aims at presenting the general results achieved during my PhD, that was focused on the study and characterisation of new homoleptic and heteroleptic metal carbonyl clusters. From a dimensional point of view, the nuclearity of such species ranges from 2 to 44 metal atoms. Lower nuclearity compounds may be viewed as polymetallic complexes, whereas higher nuclearity species can reach the nanocluster size, by resembling to ultrasmall nanoparticles (USNPs). Initially, my research was focused on the investigation of small MCCs stabilised by N-Heterocyclic carbene (NHCs) ligands. At this regard, a general strategy for the synthesis of mono-anionic [Fe(CO)4(MNHC)]− and neutral Fe(CO)4(MNHC)2, Co(CO)4(MNHC) (M = Cu, Ag, Au; NHC = IMes, IPr) species has been developed. Furthermore, during this investigation, neutral trimetallic Fe(CO)4(MNHC)(M’NHC) (M, M’ = Cu, Ag, Au; M ≠ M'; NHC = IPr) and neutral heteroleptic Fe(CO)4(MNHC)(MNHC’) (M = Au; NHC = IMes, IPr) compounds have been isolated. Thermal treatment turned out to be an efficient method for the growth of the dimension of MCCs. Indeed, species of the type [M3Fe3(CO)12]3– and [M4Fe4(CO)16]4– (M = Ag, Au) as well as larger clusters were formed during the thermal treatment of the new Fe-M (M = Ag, Cu, Au) carbonyl compounds. These species inspired the investigation of promising reaction paths for the synthesis of Fe-M (M = Ag, Cu, Au) carbonyl compounds devoid of ancillary ligands and alloy MCCs, such as the heterometallic [MxM’5-xFe4(CO)16]3− (M, M' = Cu, Ag, Au; M ≠ M'; x = 0-5) carbonyl clusters. The second part of this Thesis regards high nuclearity MCCs. In particular, new strategies for the growth of platinum carbonyl clusters involving, for instance, the employment of bidentate phosphines are described, as well as the syntheses and the thermal decomposition of new Ni-M (Pd, Pt) carbonyl clusters.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Executive Summary ALT has produced this call to action to highlight to education policy makers and professionals how Open Education and OER can expand inclusive and equitable access to education and lifelong learning, widen participation, and create new opportunities for the next generation of teachers and learners, preparing them to become fully engaged digital citizens. Open Education can also promote knowledge transfer while enhancing quality and sustainability, supporting social inclusion and creating a culture of inter-institutional collaboration and sharing. One of ALT’s three strategic aims is to increase the impact of Learning Technology for the wider community and we are issuing this call to action for policy makers to mandate that publicly funded educational resources are released under open licence to ensure that they reside in the public domain and are freely and openly available to all. This will be of wide benefit, but in particular will enable education providers and learning technology professionals to: Keep up to date with the rapid pace of technological innovation Develop critical, informed approaches to the implementation of Learning Technology and the impact on learners Scale up knowledge sharing and its benefits across sectors.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9% saline, ethyl alcohol, Emulphor® (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We present a re-analysis of the Geneva-Copenhagen survey, which benefits from the infrared flux method to improve the accuracy of the derived stellar effective temperatures and uses the latter to build a consistent and improved metallicity scale. Metallicities are calibrated on high-resolution spectroscopy and checked against four open clusters and a moving group, showing excellent consistency. The new temperature and metallicity scales provide a better match to theoretical isochrones, which are used for a Bayesian analysis of stellar ages. With respect to previous analyses, our stars are on average 100 K hotter and 0.1 dex more metal rich, which shift the peak of the metallicity distribution function around the solar value. From Stromgren photometry we are able to derive for the first time a proxy for [alpha/Fe] abundances, which enables us to perform a tentative dissection of the chemical thin and thick disc. We find evidence for the latter being composed of an old, mildly but systematically alpha-enhanced population that extends to super solar metallicities, in agreement with spectroscopic studies. Our revision offers the largest existing kinematically unbiased sample of the solar neighbourhood that contains full information on kinematics, metallicities, and ages and thus provides better constraints on the physical processes relevant in the build-up of the Milky Way disc, enabling a better understanding of the Sun in a Galactic context.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Our group have recently proposed that low prenatal vitamin D may be a risk-modifying factor for schizophrenia. Climate variability impacts on vitamin D levels in a population via fluctuations in the amount of available UV radiation. In order to explore this hypothesis, we examined fluctuations in the birthrates for people with schizophrenia born between 1920 and 1967 and three sets of variables strongly associated with UV radiation. These included: (a) the Southern Oscillation Index (SOI), a marker of El Nino which is the most prominent meteorological factor that influences Queensland weather: (b) measures of cloud cover and (c) measures of sunshine. Schizophrenia births were extracted from the Queensland Mental Health register and corrected for background population birth rates. Schizophrenia birth rates had several apparently non-random features in common with the SO1. The prominent SO1 fluctuation event that occurred between 1937 and 1943 is congruent with the most prominent fluctuation in schizophrenia birth rates. The relatively flat profile of SOI activity between 1927 and 1936 also corresponds to the flattest period in the schizophrenia time series. Both time series have prominent oscillations in the 3 ~, year range between 1946 and 1960. Significant associations between schizophrenia birth rates and measures of both sunshine and cloud cover were identified,and all three time series shared periodicity in the 3-4 year range. The analyses suggest that the risk of schizophrenia is higher for those born during times of increased cloud cover,reduced sunshine and positive SO1. These ecological analyses provide initial support for the vitamin D hypothesis, however alternative non-genetic candidate exposures also need to be considered. Other sites with year-to-year fluctuations in cloud cover and sunshine should examine patterns of association between these climate variables and schizophrenia birth rates. The Stanley Foundation supported this project.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Temperament and character traits may determine differences in clinical presentations and outcome of bipolar disorder. We compared personality traits in bipolar patients and healthy individuals using the Temperament and Character Inventory (TCI) and sought to verify whether comorbidity with alcoholism or anxiety disorders is associated with specific personality traits. Seventy-three DSM-IV bipolar patients were compared to 63 healthy individuals using the TCI. In a second step, the bipolar sample was subgrouped according to the presence of psychiatric comorbidity (alcoholism, n = 10; anxiety disorders; n = 23; alcoholism plus anxiety disorders, n = 21; no comorbidity, n = 19). Bipolar patients scored statistically higher than the healthy individuals on novelty seeking, harm avoidance and self-transcendence and lower on self-directedness and cooperativeness. Bipolar patients with only comorbid alcoholism scored statistically lower than bipolar patients without any comorbidity on persistence. Bipolar patients with only comorbid anxiety disorders scored statistically higher on harm avoidance and lower on self-directedness than bipolar patients without any comorbidity. Limitations of this study include the cross-sectional design and the small sample size, specifically in the analysis of the subgroups. However, our results suggest that bipolar patients exhibit a different personality structure than healthy individuals and that presence of psychiatric comorbidity in bipolar disorder is associated with specific personality traits. These findings suggest that personality, at least to some extent, mediates the comorbidity phenomena in bipolar disorder. (C) 2007 Elsevier Ltd. All rights reserved.