3,735 research outputs found
Observation of Microlensing towards the Galactic Spiral Arms. EROS II 2 year survey
We present the analysis of the light curves of 8.5 million stars observed
during two seasons by EROS (Experience de Recherche d'Objets Sombres), in the
galactic plane away from the bulge. Three stars have been found that exhibit
luminosity variations compatible with gravitational microlensing effects due to
unseen objects. The corresponding optical depth, averaged over four directions,
is 0.38 (+0.53, -0.15) 10^{-6}. All three candidates have long Einstein radius
crossing times ( 70 to 100 days). For one of them, the lack of evidence
for a parallax or a source size effect enabled us to constrain the lens-source
% geometric configuration. Another candidate displays a modulation of the
magnification, which is compatible with the lensing of a binary source.
The interpretation of the optical depths inferred from these observations is
hindered by the imperfect knowledge of the distance to the target stars. Our
measurements are compatible with expectations from simple galactic models under
reasonable assumptions on the target distances.Comment: 11 pages, 13 figures, accepted by A&A in Aug 9
Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges
Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI‐2/2, and HbI‐1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10°C to their critical thermal maximum [CTM] or 22°C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10°C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9° ± 0.2°C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbI‐1/1 fish grew more (by 15%–30% during the first 9 mo) when reared at 10° ± 1°C and had a slightly enhanced hypoxia tolerance at 10°C (e.g., the critical O2 levels for HbI‐1/1, HbI‐2/2, and HbI‐1/2 cod were 35.56% ± 1.24%, and 40.20% ± 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply—that is, reduced standard metabolic rates and/or increased metabolic capacity—and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.<br /
Microjansky sources at 1.4 GHz
We present a deep 1.4 GHz survey made with the Australia Telescope Compact
Array (ATCA), having a background RMS of 9 microJy near the image phase centre,
up to 25 microJy at the edge of a 50' field of view. Over 770 radio sources
brighter than 45 microJy have been catalogued in the field. The differential
source counts in the deep field provide tentative support for the growing
evidence that the microjansky radio population exhibits significantly higher
clustering than found at higher flux density cutoffs. The optical
identification rate on CCD images is approximately 50% to R=22.5, and the
optical counterparts of the faintest radio sources appear to be mainly single
galaxies close to this optical magnitude limit.Comment: 6 pages, 4 figures, accepted by ApJ Letters 4 May 199
The Tip of the Iceberg: Cutaneous Manifestations of Paediatric Diseases with Neurological Involvement
Introdução: Algumas alterações cutâneas podem ser as primeiras manifestações clínicas de diversas entidades nosológicas com
atingimento sistémico. O presente trabalho tem como objectivo rever a semiologia dermatológica relevante no contexto das doenças com envolvimento neurológico na infância.
Material e Métodos: Revisão dos artigos indexados à MedLine publicados nos últimos 12 anos e com relevância para o tema.
Resultados: Os principais grupos nosológicos relevantes para o tema compreendem as genodermatoses (com destaque para as
síndromes neurocutâneas), as alterações da pigmentação, as doenças vasculares, as endócrinas, os défices enzimáticos congénitos
e os disrafismos espinhais ocultos.
Discussão: O reconhecimento da semiologia cutânea específica é importante pois pode permitir um diagnóstico muito mais precoce
Performance comparison of Machine Learning algorithms in classifying information technologies incident tickets
Technological problems related to everyday work elements are real, and IT professionals can solve them. However, when they encounter a problem, they must go to a platform where they can detail the category and textual description of the incident so that the support agent understands. However, not all employees are rigorous and accurate in describing an incident, and there is often a category that is totally out of line with the textual description of the ticket, making the deduction of the solution by the professional more time-consuming. In this project, a solution is proposed that aims to assign a category to new incident tickets through their classification, using Text Mining, PLN and ML techniques, to try to reduce human intervention in the classification of tickets as much as possible, reducing the time spent in their perception and resolution. The results were entirely satisfactory and allowed to us determine which are the best textual processing procedures to be carried out, subsequently achieving, in most of the classification models, an accuracy higher than 90%, making its implementation legitimate.This work has been suported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020
Hipertiroidismo por Secreção Inapropriada Não Tumoral de TSH
Apresenta-se um caso clínico de hipertiroidismo por secreção inapropriada não tumoral de TSH, numa mulher de 31 anos, investigado na sequência do achado de T3 e TSH elevados após tiroidecto
mia. A resposta exagerada de TSH à TRH e a supressão parcial após triiodotironina aliadas à normal expressão morfológica tomodensitométrica da região selar confirmaram o diagnóstico. As terapêuticas
com bromocriptina e ocjreotido revelaram-se ineficazes na supressa da TSH. O ensaio com 3-5-3’ ácido triiodotiroacético ficou deferido pela ocorrência de gravidez e aleitamento
An efficient adaptive data-link-layer architecture for LoRa networks
LoRa is one of the most popular low-power wireless network technologies for implementation of the Internet of Things, with the advantage of providing long-range communication, but lower data rates, when compared with technologies such as Zigbee or Bluetooth. LoRa is a single-channel physical layer technology on top of which LoRaWAN implements a more complex multi-channel network with enhanced functionalities, such as adaptive data rate. However, LoRaWAN relies on expensive hardware to support these functionalities. This paper proposes a LoRa data-link-layer architecture based on a multi-layer star network topology that adapts relevant LoRa parameters for each end node dynamically taking into account its link distance and quality in order to balance communication range and energy consumption. The developed solution is comprised of multiple components, including a LoRa parameter calculator to help the user to configure the network parameters, a contention-free MAC protocol to avoid collisions, and an adaptive spreading factor and transmission power mechanism. These components work together to ensure a more efficient use of the chosen ISM band and end node resources, but with low-cost implementation and operation requirements.This research was funded by FEDER through COMPETE2020—Programa Operacional
Competitividade e Internacionalização (POCI) grant number POCI-01-0145-FEDER-028247 and by
FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/202
Schwannoma, a rare tumor of the seminal vesicle
We present a rare case of a schwannoma of the seminal vesicle that occurred in a 43-year-old male with symptoms of the lower urinary tract. Ultrasonography and magnetic resonance imaging documented a solid mass in the patient's left seminal vesicle. A transvesical approach with a transtrigonal midline incision was successfully performed. The microscopic aspect was compatible with schwannoma
Business Against Markets: Employer Resistance to Collective Bargaining Liberalization During the Eurozone Crisis
Employer organizations have been presented as strong promoters of the liberalization of industrial relations in Europe. This article, in contrast, argues that the preferences of employers vis-à-vis liberalization are heterogeneous and documents how employer organizations in Spain, Italy, and Portugal have resisted state-led reforms to liberalize collective bargaining during the Euro crisis. It shows that the dominance of small firms in the economies of these countries make employer organizations supportive of selective aspects of sectoral bargaining and state regulation. Encompassing sectoral bargaining is important for small firms for three reasons: it limits industrial conflict, reduces transaction costs related to wage-bargaining, and ensures that member firms are not undercut by rivals offering lower wages and employment conditions. Furthermore, the maintenance of sectoral bargaining and its extension to whole sectors by the state is a matter of survival for employer organizations. The article presents rationales for employer opposition to liberalization that differ from the varieties of capitalism approach.Introduction Collective Bargaining and Employer Preferences in Southern Europe Cases and Methods Italy Spain Portugal Conclusions Acknowledgements Notes Reference
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