Leveraging explicitly disclosed location information to understand tourist dynamics: a case study

In recent years, the large deployment of mobile devices has led to a massiveincrease in the volume of records of where people have been and when they were there.The analysis of these spatio-temporal data can supply high-level human behaviorinformation valuable to urban planners, local authorities, and designer of location-basedservices. In this paper, we describe our approach to collect and analyze the history ofphysical presence of tourists from the digital footprints they publicly disclose on the web.Our work takes place in the Province of Florence in Italy, where the insights on thevisitors’ flows and on the nationalities of the tourists who do not sleep in town has beenlimited to information from survey-based hotel and museums frequentation. In fact, mostlocal authorities in the world must face this dearth of data on tourist dynamics. In thiscase study, we used a corpus of geographically referenced photos taken in the provinceby 4280 photographers over a period of 2 years. Based on the disclosure of the locationof the photos, we design geovisualizations to reveal the tourist concentration and spatiotemporalflows. Our initial results provide insights on the density of tourists, the points ofinterests they visit as well as the most common trajectories they follow.

On the origin of the MR image phase contrast: an in vivo MR microscopy study of the rat brain at 14.1 T.

Recent studies at high magnetic fields using the phase of gradient-echo MR images have shown the ability to unveil cortical substructure in the human brain. To investigate the contrast mechanisms in phase imaging, this study extends, for the first time, phase imaging to the rodent brain. Using a 14.1 T horizontal bore animal MRI scanner for in vivo micro-imaging, images with an in-plane resolution of 33 microm were acquired. Phase images revealed, often more clearly than the corresponding magnitude images, hippocampal fields, cortical layers (e.g. layer 4), cerebellar layers (molecular and granule cell layers) and small white matter structures present in the striatum and septal nucleus. The contrast of the phase images depended in part on the orientation of anatomical structures relative to the magnetic field, consistent with bulk susceptibility variations between tissues. This was found not only for vessels, but also for white matter structures, such as the anterior commissure, and cortical layers in the cerebellum. Such susceptibility changes could result from variable blood volume. However, when the deoxyhemoglobin content was reduced by increasing cerebral blood flow (CBF) with a carbogen breathing challenge, contrast between white and gray matter and cortical layers was not affected, suggesting that tissue cerebral blood volume (and therefore deoxyhemoglobin) is not a major source of the tissue phase contrast. We conclude that phase variations in gradient-echo images are likely due to susceptibility shifts of non-vascular origin.

CT arthrography of the glenohumeral joint: CT fluoroscopy versus conventional CT and fluoroscopy--comparison of image-guidance techniques.

PURPOSE: To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography. MATERIALS AND METHODS: Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software. RESULTS: Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv. CONCLUSION: CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality--preliminary findings.

BACKGROUND: Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. OBJECTIVE: To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. MATERIALS AND METHODS: Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI(vol) 4.8-7.9 mGy, DLP 37.1-178.9 mGy·cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. RESULTS: The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. CONCLUSION: Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone.

Perceived self-image in adolescent idiopathic scoliosis: an integrative review of the literature

Objective: To learn about the experiences of adolescents diagnosed with idiopathic scoliosis. Method: Integrative review of the literature published within a specified time frame. Results: For both sexes, the predominant clinical symptom of this condition appears to be the negative effect that the deformity exerts on perceived self-image. Quantitative studies used numerical scores to assess perceptions of body image but did not analyse emotional aspects. Patients treated surgically were found to have a better self-image than patients treated with a brace. Quality of life was improved by a reduction in the magnitude of the curve. Conclusion: Spinal deformity exerts a psychological effect on adolescent girls.


Trabecular bone score: a noninvasive analytical method based upon the DXA image.

The trabecular bone score (TBS) is a gray-level textural metric that can be extracted from the two-dimensional lumbar spine dual-energy X-ray absorptiometry (DXA) image. TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard bone mineral density (BMD) measurement. Based on experimental variograms of the projected DXA image, TBS has the potential to discern differences between DXA scans that show similar BMD measurements. An elevated TBS value correlates with better skeletal microstructure; a low TBS value correlates with weaker skeletal microstructure. Lumbar spine TBS has been evaluated in cross-sectional and longitudinal studies. The following conclusions are based upon publications reviewed in this article: 1) TBS gives lower values in postmenopausal women and in men with previous fragility fractures than their nonfractured counterparts; 2) TBS is complementary to data available by lumbar spine DXA measurements; 3) TBS results are lower in women who have sustained a fragility fracture but in whom DXA does not indicate osteoporosis or even osteopenia; 4) TBS predicts fracture risk as well as lumbar spine BMD measurements in postmenopausal women; 5) efficacious therapies for osteoporosis differ in the extent to which they influence the TBS; 6) TBS is associated with fracture risk in individuals with conditions related to reduced bone mass or bone quality. Based on these data, lumbar spine TBS holds promise as an emerging technology that could well become a valuable clinical tool in the diagnosis of osteoporosis and in fracture risk assessment.

Perfil dos Turistas que Visitam a Ilha de São Vicente

O presente trabalho tem por objectivo definir o perfil do turista que visitou a ilha de São Vicente e avaliar o grau de satisfação do turista enquanto consumidor de diferentes bens e serviços, nos meses de Maio e Junho do decorrente ano. Para se fazer uma abordagem qualitativa falou-se da problemática do mercado turístico - procura e oferta turística – e a importância da segmentação desse sistema turístico juntamente com algumas teorias do comportamento do consumidor. Por sua vez, para o estudo do perfil e satisfação dos turistas utilizou-se uma abordagem quantitativa, através da aplicação de questionários no Aeroporto Internacional Cesária Évora e entrevistas aos estabelecimentos hoteleiros, 150 e 7 respectivamente. Após a análise explicativa, com base na bibliografia seleccionada, nas entrevistas e questionários realizados, os resultados da pesquisa indicam que estudar o perfil e a satisfação dos turistas permite fazer um levantamento de diversas variáveis importantes como, por exemplo, a nacionalidade do turista, a principal razão e objectivo da viagem e o que gostaram, ou desejavam ver no destino. E assim, entender-se o perfil do visitante e propor-se estratégias, que contribuam para um planeamento sustentável do desenvolvimento turístico na região pretendida. A complexidade do processo de decisão do turista por um ou outro destino é que verdadeiramente motiva esta pesquisa. The objective of the following work is to define the profile of a tourist that visited São Vicente, and evaluate the levels of satisfaction of the tourist as a consumer of different items and services, on May and June of the current year. For a quality methodological approach, the problematic of the touristic industry (demand and touristic offer) – the essential of subdivision of these touristic systems alongside with the principles of the consumer behavior were discussed. In continuity, to define the profile and satisfaction of the tourists, a quantity approach was also used, through the application of questionnaires at the International Airport Cesária Évora and interviews throughout hotel establishments, 150 and 7 respectively. After an explanatory analyses, based on a selected bibliography, the applied interviews and questionnaires, the outcome of this research shows that by studying the profile and the satisfaction of the tourists allows to have variable important results, for example, the tourist´s nationality, the main reason and objective of the trip and what they enjoyed or would like to see on their destination. Thus, understanding the visitor´s profile and suggesting strategies, that contributes for a sustainable planning of a touristic development on the intended region. The process complexity of the decision making of the tourist for one destination is truly the main motivation for this research.

Entre a Terra e o Mar - Grau de Satisfação dos Cruzeiristas na Ilha de São Vicente

Este trabalho apresenta os resultados de um estudo realizado em São Vicente, de Março a Abril de 2012 a turistas de cruzeiro. Este estudo teve como objectivo analisar o perfile a satisfação dos visitantes durante a sua estadia na ilha, para ajudar a indústria do turismo na melhoria do produto e infra-estrutura turística, e ao fazê-lo melhorar aexperiência para os cruzeiristas. O estudo foi conduzido através da revisão da literaturasobre turismo de cruzeiro, imagem do destino, elementos da oferta turística, qualidade esatisfação e sua relação com o turismo. Para a avaliação do perfil e satisfação do turistade cruzeiro, aplicou-se um questionário a uma amostra de 131 cruzeiristas, no fim dasua visita à ilha. Os resultados do questionário aplicado aos cruzeiristas evidenciaram maior satisfação com aspectos como paisagem natural, clima, simpatia da população local, oportunidadepara conhecer pessoas e limpeza urbana. Os atributos que demonstraram valores maisaltos de insatisfação são: museus, sanitários, gastronomia, sinalização, serviços derestauração e de informação turística. O perfil do cruzeirista é caracterizado pela disponibilidade em viajar, nível académico eprofissional médio alto, poder de compra médio alto e de média idade. Verificou-se que os vários sectores não estão bem organizados e integrados entre si paraatender às necessidades e desejos dos visitantes. Assim, recomenda-se uma série deactividades, tendo em vista, minimizar os aspectos negativos identificados peloscruzeiristas e integrar a oferta turística entre os vários elementos que a compõem. This research is based on the results acquired from tourists who traveled to the island of Sao Vicente on cruise ships during the months of March and April of 2012. The object of this study was to analyze the characteristics and level of satisfaction of those visiting the island of Sao Vicente, in order to help improve the tourism industry, and its infrastructure in hopes of bettering the overall experience for cruise tourists. The study emerged from a profound revision of cruise ship literature, now detailing destination images, available touristic elements, as well as quality and satisfaction ratings in relationship to tourism. In order to measure the satisfaction of the tourists we implemented a questionnaire where a sample of 131 people was surveyed at the end of their visit to the island. The questionnaire resulted in evidence detailing higher satisfaction regarding natural landscape, climate, local acceptance, ability to meet others and urban cleanliness. However, elements such as museums, sanitation, gastronomy, signage, restaurant services and travel information demonstrated higher levels of dissatisfaction. Cruise tourists are characterized as middle aged, frequent travelers with high academic and professional levels, and by their ability to consume heavily. This study verifies that various elements within the tourism sector are not well organized to satisfy the necessities and desires of cruise tourists. Therefore, an implementation of more activities is recommended for those visiting the island of Sao Vicente on cruise ships. While considering the need to minimize the negative aspects identified by the surveyed cruise tourists it is also important to integrate the offered tourist attractions within the various elements that embody tourism.

Management of patient dose and image noise in routine pediatric CT abdominal examinations.

The aim was to propose a strategy for finding reasonable compromises between image noise and dose as a function of patient weight. Weighted CT dose index (CTDI(w)) was measured on a multidetector-row CT unit using CTDI test objects of 16, 24 and 32 cm in diameter at 80, 100, 120 and 140 kV. These test objects were then scanned in helical mode using a wide range of tube currents and voltages with a reconstructed slice thickness of 5 mm. For each set of acquisition parameter image noise was measured and the Rose model observer was used to test two strategies for proposing a reasonable compromise between dose and low-contrast detection performance: (1) the use of a unique noise level for all test object diameters, and (2) the use of a unique dose efficacy level defined as the noise reduction per unit dose. Published data were used to define four weight classes and an acquisition protocol was proposed for each class. The protocols have been applied in clinical routine for more than one year. CTDI(vol) values of 6.7, 9.4, 15.9 and 24.5 mGy were proposed for the following weight classes: 2.5-5, 5-15, 15-30 and 30-50 kg with image noise levels in the range of 10-15 HU. The proposed method allows patient dose and image noise to be controlled in such a way that dose reduction does not impair the detection of low-contrast lesions. The proposed values correspond to high- quality images and can be reduced if only high-contrast organs are assessed.

Turismo em Cabo Verde:um estudo exploratório

Esta dissertação é um trabalho exploratório sobre o turismo em Cabo Verde. Partindo de um esquema teórico herdeiro fundamentalmente da Sociologia e Antropologia do turismo, começaremos por discutir alguns dos seus temas centrais para o nosso objecto de estudo. O turismo em Cabo Verde é assumido como o eixo central do desenvolvimento do país e a indústria turística cabo-verdiana encontra-se em franca expansão. Através de uma caracterização do fenómeno turístico em Cabo Verde, desde o seu florescimento até aos dias de hoje, pretendemos dar conta da evolução do sector e das recentes reconfigurações no panorama turístico cabo-verdiano que se espelham nos discursos narrativos e visuais presentes na promoção turística deste destino. Com base numa análise do discurso promocional, procuramos desvendar a forma como este arquipélago é descrito enquanto destino turístico, revelando a diversidade de elementos presentes na imagem turística contemporânea de Cabo Verde.