3,707 research outputs found
Identifying Multiply-Scattered Wavepaths in Strongly Scattering and DispersiveMedia
The ability to extract information from scattered waves is usually limited to singly scattered energy even if multiple scattering might occur in the medium. As a result, the information in arrival times of higher-order scattered events is underexplored. This information is extracted using fingerprinting theory. This theory has never previously been applied successfully to real measurements, particularly when the medium is dispersive. The theory is used to estimate the arrival times and scattering paths of multiply scattered waves in a thin sheet using an automated scheme in a dispersive medium by applying an additional dispersion compensation method. Estimated times and paths are compared with predictions based on a sequence of straight ray paths for each scattering event given the known scatterer locations. Additionally, numerical modelling is performed to verify the interpretations of the compensated data. Since the source also acts as a scatterer in these experiments, initially, the predictions and the numerical results did not conform to the experimental observations. By reformulating the theory and the processing scheme and adding a source scatterer in the modelling, it is shown that predictions of all observed scattering events are possible with both prediction methods, verifying that the methods are both effective and practically achievable. Applied Geophysics and Petrophysic
Initial fixation placement in face images is driven by top-down guidance
The eyes are often inspected first and for longer period during face exploration. To examine whether this saliency of the eye region at the early stage of face inspection is attributed to its local structure properties or to the knowledge of its essence in facial communication, in this study we investigated the pattern of eye movements produced by rhesus monkeys (Macaca mulatta) as they free viewed images of monkey faces. Eye positions were recorded accurately using implanted eye coils, while images of original faces, faces with scrambled eyes, and scrambled faces except for the eyes were presented on a computer screen. The eye region in the scrambled faces attracted the same proportion of viewing time and fixations as it did in the original faces, even the scrambled eyes attracted substantial proportion of viewing time and fixations. Furthermore, the monkeys often made the first saccade towards to the location of the eyes regardless of image content. Our results suggest that the initial fixation placement in faces is driven predominantly by ‘top-down’ or internal factors, such as the prior knowledge of the location of “eyes” within the context of a face
Routes to diagnosis and the association with the prognosis in patients with cancer – A nationwide register-based cohort study in Denmark
Background: The prognosis of cancer is related to how the cancer is identified, and where in the healthcare system the patient presents, i.e. routes to diagnosis (RtD). We aimed to describe the RtD for patients diagnosed with cancer in Denmark by using routinely collected register-based data and to investigate the association between RtD and prognosis measured as one-year all-cause mortality. /
Methods: We conducted a population-based national cohort study by linking routinely collected Danish registry data. We categorised each patient into one of eight specified RtD based on an algorithm using a stepwise logic decision process. We described the proportions of patients with cancer diagnosed by different RtD. We examined associations between RtD and one-year all-cause mortality using logistic regression models adjusting for sex, age, cancer type, year of diagnosis, region of residence, and comorbidity. /
Results: We included 144,635 cancers diagnosed in 139,023 patients in 2014–2017. The most common RtD were cancer patient pathway from primary care (45.9 %), cancer patient pathway from secondary care (20.0 %), unplanned hospital admission (15.8 %), and population-based screening (7.5 %). The one-year mortality ranged from 1.4 % in screened patients to 53.0 % in patients diagnosed through unplanned hospital admission. Patients with an unplanned admission were more likely to die within the first year after diagnosis (OR = 3.38 (95 %CI: 3.24–3.52)) compared to patients diagnosed through the cancer patient pathway from primary care. /
Conclusion: The majority of cancer patients were diagnosed through a cancer patient pathway. The RtD were associated with the prognosis, and the prognosis was worst in patients diagnosed through unplanned admission. The study suggests that linking routinely collected registry data could enable a national framework for RtD, which could serve to identify variations across patient-, health-, and system-related and healthcare factors. This information could be used in future research investigating markers for monitoring purposes
Winter wheat roots grow twice as deep as spring wheat roots, is this important for N uptake and N leaching losses?
Cropping systems comprising winter catch crops followed by spring wheat could reduce N leaching risks compared to traditional winter wheat systems in humid climates. We studied the soil mineral N (Ninorg) and root growth of winter- and spring wheat to 2.5 m depth during three years. Root depth of winter wheat (2.2 m) was twice that of spring wheat, and this was related to much lower amounts of Ninorg in the 1 to 2.5 m layer after winter wheat (81 kg Ninorg ha-1 less). When growing winter catch crops before spring wheat, N content in the 1 to 2.5 m layer after spring wheat was not different from that after winter wheat. The results suggest that by virtue of its deep rooting, winter wheat may not lead to high levels of leaching as it is often assumed in humid climates. Deep soil and root measurements (below 1 m) in this experiment were essential to answer the questions we posed
Imagen y propaganda en las primeras amonedaciones del rey de Aragón
This study analyzes aspects of the iconographic repertoire that contributed to reaffirm and strengthen the royal power of one of the most emblematic kings of Aragon of the late eleventh century: Sancho Ramírez. The effigies stamped on his first coins, which should be considered among his most effective propaganda vehicles, will be studied, as will an element that reached a symbolic significance only understandable in relation to the royal institution that, in turn, promoted it: the cross, now developed as the clearest element of monarchical proclamation. In addition to considering the political motivations that lie beneath these representations, the relevance of the county of Urgell will be discussed and, in connection with it, Doña Sancha, a figure worthy of deeper investigation.Este estudio analiza parte del repertorio iconográfico que contribuyó a reafirmar y fortalecer el poder real de uno de los más emblemáticos reyes de Aragón de finales del siglo XI: Sancho Ramírez. Además de profundizar sobre las efigies estampadas en sus primeras monedas, efectivo vehículo de propaganda, se abordará otro elemento que alcanzó una trascendencia simbólica sólo explicable en relación con esta regia institución que, a su vez, la promocionaba: la cruz, que ahora se convertirá en elemento de proclamación monárquica. Además de examinar las motivaciones políticas que subyacen bajo estas representaciones, se evidenciará la relevancia del condado de Urgell y, en relación con él, la personalidad de doña Sancha, sobre la que tanto merecería profundizar
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