2,080 research outputs found

    Adding rotation to translation: percepts and illusions

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    This study investigated how the perception of a translating object is affected by rotation. Observers were asked to judge the motion and trajectory of objects that rotated around their centroid while linearly translating. The expected percept, consistent with the actual dynamics used to generate the movie sequences, is that of a translating and rotating object, akin to a tumbling rugby ball. Observers, however, do not always report this and, under certain circumstances, perceive the object to translate on an illusory curved trajectory, similar to a car driving on a curved road. The prevalence of veridical versus nonveridical percepts depends on a number of factors. First, if the object's orientation remains within a limited range relative to the axis of translation, the illusory, curved percept dominates. If the orientation, at any point of the movie sequence, differs sufficiently from the axis of translation, the percept switches to linear translation with rotation. The angle at which the switch occurs is dependent upon a number of factors that relate to an object's elongation and, with it, the prominence of its orientation. For an ellipse with an aspect ratio of 3, the switch occurs at approximately 45°. Higher aspect ratios increase the range; lower ratios decrease it. This applies similarly to rectangular shapes. A line is more likely to be perceived on a curved trajectory than an elongated rectangle, which, in turn, is more likely seen on a curved path than a square. This is largely independent of rotational and translational speeds. Measuring perceived directions of motion at different instants in time allows the shape of the perceived illusory curved path to be extrapolated. This results in a trajectory that is independent of object size and corresponds closely to the actual object orientation at different points during the movie sequence. The results provide evidence for a perceptual transition from an illusory curved trajectory to a veridical linear trajectory (with rotation) for the same object. Both are consistent with special real-world cases such as objects rotating around a centre outside of the object so that their orientation remains tangent to the trajectory (cheetahs running along a curve, sailboats) or objects tumbling along simple trajectories (a monkey spinning in air, spinning cars on ice). In certain cases, the former is an illusion. </jats:p

    Centralized or decentralized? A case study of Norwegian hospital reform

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    In recent years, decentralization of financial and political power has been perceived as a useful means to improve outcomes of the health care sector. Such reforms are often a result of fashion, rather than being based on knowledge of “what works”. If decentralization is the favored strategy in health care, studies of countries that go against the current trend will be of interest and importance as they provide information about the potential drawbacks of decentralization. In Norway, specialized health care has recently been recentralized. In this paper, we review some of the evidence now available on its economic effects. The most striking observation is that recentralization did not affect the variables related to cost containment and soft budgeting.Health care system; decentralization; recentralization; Norway.

    Dihydroartemisinin-piperaquine versus artesunate-amodiaquine for treatment of malaria infection in pregnancy in Ghana: an open-label, randomized, non-inferiority trial.

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    To determine whether dihydroartemisinin-piperaquine (DHA-PPQ) is non-inferior to artesunate-amodiaquine (ASAQ) for treating uncomplicated malaria infection in pregnancy. 417 second/ third trimester pregnant women with confirmed asymptomatic Plasmodium falciparum parasitaemia were randomized to receive DHA-PPQ or ASAQ over 3 days. Women were followed up on days 1, 2, 3, 7, 14, 28 and 42 after treatment start and at delivery for parasitological, haematological, birth outcomes and at 6-weeks post-partum to ascertain the health status of the babies. Parasitological efficacy (PE) by days 28 and 42 were co-primary outcomes. Analysis was per-protocol (PP) and modified intention-to-treat (ITT). Non-inferiority was declared if the two-sided 95% confidence interval for PE at the endpoints excluded 5% lower efficacy for DHA-PPQ. Secondary outcomes were assessed for superiority. In PP analysis, PE was 91.6% for DHA-PPQ and 89.3% for ASAQ by day 28 and 89.0% and 86.5% respectively by day 42. DHA-PPQ was non-inferior to ASAQ with respect to uncorrected PE {adjusted difference by day 28 (DHA-PPQ-ASAQ); 3.5% (95%CI: -1.5, 8.5) and day 42: 3.9% (95%CI: -2.7, 10.4)}. ITT analysis gave similar results. PCR to distinguish recrudescence and reinfection was unsuccessful. DHA-PPQ recipients had fewer adverse events of vomiting, dizziness and general weakness compared to ASAQ. Both drugs were well-tolerated and there was no excess of adverse birth outcomes. DHA-PPQ was non-inferior to ASAQ for treatment of malaria infection during pregnancy. No safety concerns were identified. Our findings contribute to growing evidence that DHA-PPQ is useful for control of malaria in pregnancy. This article is protected by copyright. All rights reserved

    Maltreated and non-maltreated children's true and false memories of neutral and emotional word lists in the DRM task

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    Maltreated (n = 26) and non - maltreated (n = 31) 7 - to 12 - year - old children were tested on the Deese/Roediger - McDermot (DRM) false memory task using emotional and neutral word lists. True recall was significantly better for non - maltreated than maltreated children regardless of list valence. The proportion of false recall for neutral lists was comparable regardless of maltreatment status. However, maltreated children showed a significantly higher false recall rate for the emotional lists than non - maltreated children. Together, these results provide new evidence that maltreated children could be more prone to false memory illusions for negatively - valenced information than their non - maltreated counterparts

    Evidences on overweight of regular blood donors in a center of Southern Italy

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    Objective: Smoking, unhealthy diet and obesity, sedentary behavior and inability to maintain adequate exercise have significant consequences for several chronic disorders. Blood centers can play a public health role in obesity surveillance and interventions. The purpose study was to evaluate the health status of the blood donors by monitoring the nutritional habits and lifestyle. Methods: A descriptive cross-sectional face-to-face questionnaire was developed. It included a 41 item dietary assessment, reporting semi-quantitative food frequency, dietary behavior and questions on self-rated health status. Donors were regular repeat blood donors, eligible to donate. Results: Of the 2468 blood donors enrolled between July 2017 and January 2018, 1390 were repeat donors. Only 205 agreed to respond to the questionnaire. Data showed that donors followed mainly a Mediterranean diet and had more awareness to lifestyle, women more than men, in comparison with general population. The prevalence of overweight was found 50.7% in men and 16.9% in women. Conclusions: Overweight and obesity are common among regular blood donors and it is more frequent in men than women. The female blood donors seem to be characterized by better knowledge on the relationship between lifestyle and health, and by a better “putting into practice” of the information possessed

    Light cigarette smoking increases risk of all-cause and cause-specific mortality: Findings from the NHIS Cohort Study

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    Very few studies have examined the association between light cigarette smoking (i.e., ≤5 cigarettes per day) and mortality. The aim of this study was to examine the association of light cigarette smoking with all-cause and cause-specific mortality among adults in the United States. Data were from 13 waves of the National Health Interview Survey (1997 to 2009) that were linked to the National Death Index records through December 31, 2011. A total of 329,035 participants aged ≥18 years in the United States were included. Deaths were from all cause, cancer, cardiovascular disease (CVD) and respiratory disease and were confirmed by death certification. During a median follow-up of 8.2 years, 34,862 participants died, of which 8415 were from cancer, 9031 from CVD, and 2040 from respiratory disease. Compared with never-smokers, participants who smoked 1-2 (hazard ratios (HR) = 1.94, 95%CI = 1.73-2.16) and 3-5 cigarettes (HR = 1.99, 1.83-2.17) per day were at higher risk of all-cause mortality after adjustment for demographic variables, lifestyle factors and physician-diagnosis of chronic disease. The associations were stronger for respiratory disease-specific mortality, followed by cancer-specific mortality and CVD-specific mortality. For example, the HRs (95% CIs) of smoking 1-2 cigarettes per day were 9.75 (6.15-15.46), 2.28 (1.84-2.84) and 1.93 (1.58-2.36), respectively, for these three cause-specific mortalities. This study indicates that light cigarette smoking increases risk of all-cause and cause-specific mortality in US adults

    The impact of anthelmintic treatment intervention on malaria infection and anaemia in school and preschool children in Magu district, Tanzania: an open label randomised intervention trial.

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    BACKGROUND: Some studies have suggested that helminth infections increase the risk of malaria infection and are associated with increased number of malaria attacks and anaemia. Thus interventions to control helminth infections may have an impact on incidence of clinical malaria and anaemia. The current study assessed the impact of two anthelmintic treatment approaches on malaria infection and on anaemia in school and pre-school children in Magu district, Tanzania. METHODS: A total of 765 children were enrolled into a prospective randomized anthelmintic intervention trial following a baseline study of 1546 children. Enrolled children were randomized to receive either repeated treatment with praziquantel and albendazole four times a year (intervention group, 394 children) or single dose treatment with praziquantel and albendazole once a year (control group, 371 children). Follow up examinations were conducted at 12 and 24 months after baseline to assess the impact of the intervention. Stool and urine samples were collected and examined for schistosome and soil transmitted helminth infections. Blood samples were also collected and examined for malaria parasites and haemoglobin concentrations. Monitoring of clinical malaria attacks was performed at each school during the two years of the intervention. RESULTS: Out of 1546 children screened for P. falciparum, S. mansoni, S. haematobium, hookworm and T. Trichiura at baseline, 1079 (69.8%) were infected with at least one of the four parasites. There was no significant difference in malaria infection (prevalence, parasite density and frequency of malaria attacks) and in the prevalence of anaemia between the repeated and single dose anthelmintic treatment groups at 12 and 24 months follow up (p>0.05). However, overall, there was significant improvement in mean haemoglobin concentrations (p<0.001) from baseline levels of 122.0 g/L and 123.0 g/L to 136.0 g/L and 136.8 g/L for the repeated and single dose treatment groups, respectively, at 24 months follow-up which resulted in significant reduction in prevalence of anaemia. CONCLUSIONS: These results suggest that repeated anthelmintic treatment did not have an impact on malaria infection compared to single dose treatment. However, both treatment approaches had overall impact in terms of improvements of haemoglobin levels and hence reductions in prevalence of anaemia

    Long-term follow-up of disability pensioners having musculoskeletal disorders

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    <p>Abstract</p> <p>Background</p> <p>Previously we have conducted a randomised controlled trial (RCT) to evaluate the effect of a brief cognitive behavioural program with a vocational approach aiming to return disability pensioners with back pain to work, as compared to no intervention. One year after the intervention, 10 participants (22%) who received the program and 5 (11%) in the control group reported to have entered a return to work process. The aims of this study were to evaluate long-term effects of the intervention, and compare this effect to 2 reference populations not participating in the original trial.</p> <p>Methods</p> <p>Three groups of disability pensioners were investigated: 1) Disability pensioners having back pain (n = 89) previously participating in the RCT (randomized to either a brief cognitive behavioural intervention or to a control group), 2) 342 disability pensioners having back pain, but refusing to participate in the study and 3) 449 disability pensioners having other musculoskeletal disorders than back pain. Primary outcome was return to work, defined as a reduction in payment of disability pension.</p> <p>Results</p> <p>Only 2 of 89 (2.3%) participants from the RCT had reduced disability pension at 3-years follow-up, both from the control group. None of the participants that had been in a process of returning to work after 1 year had actually gained employment at 3-years follow-up. In the 2 groups not participating in the previous RCT, only 4 (1.2%) and 8 (1.6%) had returned to work after 3 years respectively.</p> <p>Conclusion</p> <p>The number of pensioners who returned to work was negligible in all groups regardless of having participated in a cognitive behavioural intervention or not.</p
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