844 research outputs found
Palomar 5 and its Tidal Tails::A Search for New Members in the Tidal Stream
In this paper we present the results of a search for members of the globular
cluster Palomar 5 and its associated tidal tails. The analysis has been
performed using intermediate and low resolution spectroscopy with the AAOmega
spectrograph on the Anglo-Australian Telescope. Based on kinematics, line
strength and photometric information, we identify 39 new red giant branch stars
along 20 of the tails, a larger angular extent than has been
previously studied. We also recover eight previously known tidal tail members.
Within the cluster, we find seven new red giant and one blue horizontal branch
members and confirm a further twelve known red giant members. In total, we
provide velocity data for 67 stars in the cluster and the tidal tails. Using a
maximum likelihood technique, we derive a radial velocity for Pal 5 of km s and a velocity dispersion of km s. We
confirm and extend the linear velocity gradient along the tails of km s deg, with an associated intrinsic velocity dispersion
of km s. Neither the velocity gradient nor the dispersion
change in any significant way with angular distance from the cluster, although
there is some indication that the gradient may be smaller at greater angular
distances in the trailing tail. Our results verify the tails as kinematically
cold structures and will allow further constraints to be placed on the orbit of
Pal 5, ultimately permitting a greater understanding of the shape and extent of
the Galaxy's dark matter halo.Comment: 14 pages, 9 figures, 4 tables; Accepted for publication in MNRA
A Metrological Based Realization of Time-of-Flight Diffraction Technique
AbstractTime-of-Flight Diffraction (ToFD) is a technique of non-destructive testing by ultrasound used for detecting faults and discontinuities in different components. The development and implementation of this technique was based on ISO 16828:2012 (Non-Destructive testing – Ultrasonic Testing – Time-of-Flight Diffraction Technique as a method for Detection and Sizing of Discontinuities). Controlling the different characteristics of the system, from the specification of the ultrasonic characteristics, to the imaging technique, was possible to identify the sources of uncertainty and estimate the ToFD measurement uncertainty. For a 25mm deep stainless steel test object, expanded uncertainties less than 0.5%(0.093 mm) was achieved with ToFD. For larger ultrasonic paths, the technique is able to depict even lower uncertainties, regarding some care are taken in the ultrasonic measurement setup
Ultrasound Methods for Biodiesel Production and Analysis
Ultrasonic techniques have been widely used in biodiesel production, since the acoustic cavitation is a phenomenon capable of accelerating potentially the transesterification reactions. The equipment employed in such approach was simply equipment available in any regular laboratory of chemistry. Further developments introduced the ultrasound as an important tool to produce biodiesel. The main advantage is increasing the conversion of esters at reduced reaction times, with significantly lower production costs. As a method for characterization and analysis of materials, ultrasound has been used since several decades ago. However, ultrasonic analytical methods based on metrological principles are fairly recent investigated. Using ultrasound as physical principle to interrogate biodiesel is a promising field of research, with some remarkable outcomes produced so far. The aim of this chapter is to demonstrate advances of using ultrasonic techniques in production and characterization of biodiesel, as well as an appraisal of the current technology status, and provide insights into future developments
Ultrasound as a Metrological Tool for Monitoring Transesterification Kinetics
Ultrasound has been widely used as a technological alternative way to analyse non-invasively an assortment of materials. It includes liquids with dissimilar physical characteristics, including mono- and multi-phasic mixtures, suspension formation and dissolution, in-line processing, among other practical applications. Regardless the huge spread of uses, so far ultrasound has not been proved to be able to quantify transesterification kinetics with a metrological approach. The aim of this chapter is to demonstrate that a properly designed ultrasonic experiment can be developed to identify remarkable stages of a transesterification reaction to produce biodiesel. The method was compared both with gas chromatography and hydrogen nuclear magnetic resonance (1H NMR). For an in-line application, ultrasound has been proved to work properly as a monitoring tool for chemical reaction kinetics
Fibromyalgia: description of the syndrome in athletes and its implications
Fibromyalgia syndrome is a very common feature in the daily practice of rheumatologists. Therapy is based on the use of analgesics, anti-depressants, and other drugs. Many physicians indicate exercise, stretching, and relaxing programs as adjuvant therapies. It was surprising to find fibromyalgia in well-trained athletes. The syndrome, however, appears in athletes that reported recurrent tendon-muscle lesions. In this study, the authors analyzed a group of gymnastics and track and field athletes involved in competitive training. They found a significant incidence of the syndrome (7 in 20 subjects) in this group. This is an important finding, since fibromyalgia causes muscular pain and stiffness, and can predispose the athletes to muscle lesions and damage. Another important point regarding the syndrome is that some of its symptoms are related to overtraining and to the chronic fatigue syndrome. Therefore, the authors suggest that there is an important connection between those aspects.A fibromialgia é uma patologia de alta prevalência na população geral, cujo tratamento é feito por meio de medicamentos como antiinflamatórios, antidepressivos e miorrelaxantes, que pode ser complementado por medidas físicas como relaxamento, alongamento e exercícios físicos. A observação de fibromialgia entre atletas constatada em exames de rotina, em especial naqueles que apresentavam lesões musculares de repetição, levou os autores a pesquisar, de maneira prospectiva, um grupo de atletas praticantes de ginástica olímpica e atletismo, nos quais puderam confirmar alta incidência desta síndrome. Como a fibromialgia predispõe ao aparecimento de lesões por contratura muscular, sugerem que ela possa atuar como um mecanismo de indução ao surgimento de lesões musculares de repetição. Ainda devido às semelhanças dos sintomas encontrados na síndrome do supertreinamento, síndrome da fadiga crônica e fibromialgia, propõem uma possível ligação entre estes quadros.UNIFESP-EPMPMSP COTPUNIFESP-EPM Departamento de FisiologiaUSP Departamento de HistologiaUNIFESP, EPM, Depto. de FisiologiaSciEL
Experimental evidence for adaptive divergence in response to a warmed habitat reveals roles for morphology, allometry, and parasite resistance
Ectotherms are expected to be particularly vulnerable to climate change–driven increases in temperature. Understanding how populations adapt to novel thermal environments will be key for informing mitigation plans. We took advantage of threespine stickleback (Gasterosteus aculeatus) populations inhabiting adjacent geothermal (warm) and ambient (cold) habitats to test for adaptive evolutionary divergence using a field reciprocal transplant experiment. We found evidence for adaptive morphological divergence, as growth (length change) in non-native habitats related to head, posterior and total body shape. Higher growth in fish transplanted to a non-native habitat was associated with morphological shape closer to native fish. The consequences of transplantation were asymmetric with cold sourced fish transplanted to the warm habitat suffering from lower survival rates and greater parasite prevalence than warm sourced fish transplanted to the cold habitat. We also found divergent shape allometries that related to growth. Our findings suggest that wild populations can adapt quickly to thermal conditions, but immediate transitions to warmer conditions may be particularly difficult
Electronic health record in dermatology service
In this paper we describe the implementation of an Electronic Health Record in the Dermatology service of a Portuguese hospital. This system must follow the principle of simplicity, enabling recording quality and analytical processing. Standards and norms were also followed and it is shown that interoperability has a key role in the whole process. This project is a good example of cooperation between academic and healthcare institutions and shows the impact of new technology on healthcare organizations.Fundação para a Ciência e a Tecnologia (FCT
The use of a task through virtual reality in cerebral palsy using two different interaction devices (concrete and abstract) - a cross-sectional randomized study.
BACKGROUND: Cerebral Palsy (CP) is characterised by variable difficulties in muscular action, resulting in inability of the individual to perform functional movement. An option to provide functionality to the individual with CP is the use of computer innovation. The aim of this paper was to verify if there was any performance improvement in a task performed in a virtual environment and if there was transfer to the task performed in the real environment and vice versa in this population. METHODS: A computer program was developed comprising a motor task, but with two possibilities of user interaction: a) concrete interface (with physical contact): in which the individual touches the computer screen to finish the task and b) abstract interface (no physical contact): in which the individual performs a hand movement in front of the Kinect device. Participants were split into two groups. The experimental group consisted of 28 individuals with CP within the ages of 6 and 15 years old. The control group included 28 typically developing individuals mirroring the age and sex of the experimental group. RESULTS: Individuals from both groups were able to improve task performance and retain acquired information. The CP group presented worse performance than the control group in all phases of the study. Further findings showed that the CP group presented better performance in the abstract interface than in the concrete interface, whereas, in the control group, the opposite occurred: their best performance was in the concrete. CONCLUSIONS: Motor tasks performed by individuals with CP through an interface with a more virtual environment feature (abstract interface: Kinect) provided better performance when compared to an interface with a more real characteristic (concrete interface: Touchscreen). TRIAL REGISTRATION: ClinicalTrials.gov Identifier - NCT03352440; Date of registration - November 17, 2017
Seismic Performance of Masonry Cross Vaults through Shaking Table Testing on a Scaled Model
Masonry cross vaults are among the most widely used typologies of horizontal structural elements for covering spaces of both ordinary and monumental buildings in the European countries. Their seismic vulnerability has been proved by systematic damages and collapses surveyed throughout the centuries. Therefore, the assessment of their structural safety is a crucial issue for the conservation and preservation of historical buildings. Although various methods have been developed and used to analyse both the stability (e.g. equilibrium method) and the dynamic behaviour (e.g. finite and discrete element approaches) of vaulted structures, experimental studies are constantly needed to validate and calibrate models. In this regard, limited experimental studies to understand the dynamic response of vaults have been done. The present paper describes the results of shake table tests on a 1:5 scaled cross vault model made of 3D printed blocks assembled with dry joints, carried out at the 3D LNEC shake table (Portugal). The main aim of the tests is to investigate one of the most typical seismic damage for cross vaults: the shear failure. This type of mechanism frequently affects vaults of lateral aisles and it is mainly caused by a significant difference in stiffness of vaults’ supports. Indeed, the lower stiffness of the central nave colonnade compared to the external wall may induce an in-plane shear distortion of the vault caused by a differential longitudinal displacement of its opposite sides. Incremental seismic motions are conducted up to collapse using Emilia Romagna earthquake. The results are analysed in terms crack pattern and damage mechanisms
SCI1 Is a Direct Target of AGAMOUS and WUSCHEL and Is Specifically Expressed in the Floral Meristematic Cells
The specified floral meristem will develop a pre-established number of floral organs and, thus, terminate the floral meristematic cells. The floral meristematic pool of cells is controlled, among some others, by WUSCHEL (WUS) and AGAMOUS (AG) transcription factors (TFs). Here, we demonstrate that the SCI1 (Stigma/style cell-cycle inhibitor 1) gene, a cell proliferation regulator, starts to be expressed since the floral meristem specification of Nicotiana tabacum and is expressed in all floral meristematic cells. Its expression is higher in the floral meristem and the organs being specified, and then it decreases from outside to inside whorls when the organs are differentiating. SCI1 is co-expressed with N. tabacum WUSCHEL (NtWUS) in the floral meristem and the whorl primordia at very early developmental stages. Later in development, SCI1 is co-expressed with NAG1 (N. tabacum AG) in the floral meristem and specialized tissues of the pistil. In silico analyses identified cis-regulatory elements for these TFs in the SCI1 genomic sequence. Yeast one-hybrid and electrophoresis mobility shift assay demonstrated that both TFs interact with the SCI1 promoter sequence. Additionally, the luciferase activity assay showed that NAG1 clearly activates SCI1 expression, while NtWUS could not do so. Taken together, our results suggest that during floral development, the spatiotemporal regulation of SCI1 by NtWUS and NAG1 may result in the maintenance or termination of proliferative cells in the floral meristem, respectively
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