103 research outputs found

    Robust Multi-Image HDR Reconstruction for the Modulo Camera

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    Photographing scenes with high dynamic range (HDR) poses great challenges to consumer cameras with their limited sensor bit depth. To address this, Zhao et al. recently proposed a novel sensor concept - the modulo camera - which captures the least significant bits of the recorded scene instead of going into saturation. Similar to conventional pipelines, HDR images can be reconstructed from multiple exposures, but significantly fewer images are needed than with a typical saturating sensor. While the concept is appealing, we show that the original reconstruction approach assumes noise-free measurements and quickly breaks down otherwise. To address this, we propose a novel reconstruction algorithm that is robust to image noise and produces significantly fewer artifacts. We theoretically analyze correctness as well as limitations, and show that our approach significantly outperforms the baseline on real data.Comment: to appear at the 39th German Conference on Pattern Recognition (GCPR) 201

    From multiple perspectives to shared understanding

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    The aim of this study was to explore how learners operating in a small group reach shared understanding as they work out joint research questions and build a theoretical framework and to identify the resources and tools they used in the process. The learners’ own interpretations of their group activities and learning were also taken into account. The data, consisting of group discussions and the documents produced by the group, were subjected to a qualitative content analysis. The group members employed a variety of resources and tools to exchange their individual perspectives and achieve shared understanding. Summaries of relevant literature laid a foundation for the group’s theoretical discussions. Reflective comparisons between their book knowledge and their personal experiences of online interaction and collaboration were frequent, suggesting that such juxtapositions may have enhanced their learning by intertwining the content to be mastered and the activities entailed by this particular content

    Life after hip fracture - Impact of home rehabilitation versus conventional care and patients' experiences of the recovery process in a short- and long-term perspective

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    Aim In a short- and long-term perspective compare a geriatric home rehabilitation programme (HR) for patients with hip fracture with conventional care (CC), and to capture the patients experience of the consequences of the injury and their conceptions of what influences the recovery process. Method The thesis is based on two quantitative and two qualitative studies. The two quantitative studies were randomized and controlled, longitudinal intervention studies in which 102 community-dwelling elderly patients who had received either HR (n = 48) or CC (n = 54) were followed for one year after discharge. The HR programme, which started immediately after admission to hospital, included active participation from patients in setting goals and planning discharge. The programme was focused on encouraging the participants’ self-efficacy and exercising daily activities. Assessment of balance confidence, degree of independence and frequency of daily activities, health-related quality of life, mood, perceived recovery, and basic physical performance were made one month, six months and one year after hospital discharge. In the qualitative, phenomenographic studies 18 patients were interviewed one month and one year after discharge about how they experienced the consequences of the hip fracture and their conceptions of the recovery process. Results The main recovery for all participants took place during the first six months after discharge. The results show that those who had participated in the HR programme recovered faster than those who hade received CC. Additionally, in a longer perspective they were more confident and independent than the CC group, although the differences between the groups had diminished at one year. Only 14 persons in the HR group and five persons in the CC group considered themselves fully recovered after one year. The results from the interviews showed that the hip fracture caused social and existential cracks in the individuals’ lives. The hip fracture came unexpectedly and resulted in an experience of a changed body and a more restricted life. The interviewees experienced that they had increased difficulties to move and to manage independently. One reaction was that their pre-fracture self-view as being healthy and stable had been punctured by the injury. Although positive experiences, such as being satisfied with the recovery, were also expressed, many of the negative consequences remained or had even deepened one year after discharge. A dominating experience was that they were more cautious, afraid of further falls, and felt more sedentary and isolated than before the fracture. Conclusions The results show that the negative consequences of a hip fracture are substantial and long-lasting. However, the HR programme had a more significant impact than CC on the participants’ functioning and confidence, which was most evident in the early phase of the recovery. An essential task for health care should be to create continued possibilities for rehabilitation after discharge from hospital also in a longer perspective, and not primarily focus on the medical and physical needs. The patients’ experiences and psychological reactions that may follow a hip fracture should also be considered

    Rapid cross-border emergence of NDM-5-producing Escherichia coli in the European Union/European Economic Area, 2012 to June 2022

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    Whole genome sequencing data of 874 Escherichia coli isolates carrying blaNDM-5 from 13 European Union/ European Economic Area countries between 2012 and June 2022 showed the predominance of sequence types ST167, ST405, ST410, ST361 and ST648, and an increasing frequency of detection. Nearly a third (30.6%) of these isolates were associated with infections and more than half (58.2%) were predicted to be multidrug-resistant. Further spread of E. coli carrying blaNDM-5 would leave limited treatment options for serious E. coli infections

    Exposure to Apoptotic Activated CD4+ T Cells Induces Maturation and APOBEC3G- Mediated Inhibition of HIV-1 Infection in Dendritic Cells

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    Dendritic cells (DCs) are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4+ T cells (ApoInf) or apoptotic uninfected activated CD4+ T cells (ApoAct) induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4+ T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1α, MIP-1β, MCP-1, and TNF-α; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-α using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4+ T cells (ApoRest). Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection

    Generation of neutralizing antibodies and divergence of SIVmac239 in cynomolgus macaques following short-term early antiretroviral therapy.

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    Neutralizing antibodies (NAb) able to react to heterologous viruses are generated during natural HIV-1 infection in some individuals. Further knowledge is required in order to understand the factors contributing to induction of cross-reactive NAb responses. Here a well-established model of experimental pathogenic infection in cynomolgus macaques, which reproduces long-lasting HIV-1 infection, was used to study the NAb response as well as the viral evolution of the highly neutralization-resistant SIVmac239. Twelve animals were infected intravenously with SIVmac239. Antiretroviral therapy (ART) was initiated ten days post-inoculation and administered daily for four months. Viral load, CD4(+) T-cell counts, total IgG levels, and breadth as well as strength of NAb in plasma were compared simultaneously over 14 months. In addition, envs from plasma samples were sequenced at three time points in all animals in order to assess viral evolution. We report here that seven of the 12 animals controlled viremia to below 10(4) copies/ml of plasma after discontinuation of ART and that this control was associated with a low level of evolutionary divergence. Macaques that controlled viral load developed broader NAb responses early on. Furthermore, escape mutations, such as V67M and R751G, were identified in virus sequenced from all animals with uncontrolled viremia. Bayesian estimation of ancestral population genetic diversity (PGD) showed an increase in this value in non-controlling or transient-controlling animals during the first 5.5 months of infection, in contrast to virus-controlling animals. Similarly, non- or transient controllers displayed more positively-selected amino-acid substitutions. An early increase in PGD, resulting in the generation of positively-selected amino-acid substitutions, greater divergence and relative high viral load after ART withdrawal, may have contributed to the generation of potent NAb in several animals after SIVmac239 infection. However, early broad NAb responses correlated with relatively preserved CD4(+) T-cell numbers, low viral load and limited viral divergence
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