531 research outputs found

    On the Complexity of Case-Based Planning

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    We analyze the computational complexity of problems related to case-based planning: planning when a plan for a similar instance is known, and planning from a library of plans. We prove that planning from a single case has the same complexity than generative planning (i.e., planning "from scratch"); using an extended definition of cases, complexity is reduced if the domain stored in the case is similar to the one to search plans for. Planning from a library of cases is shown to have the same complexity. In both cases, the complexity of planning remains, in the worst case, PSPACE-complete

    Enhancement by postfiltering for speech and audio coding in ad-hoc sensor networks

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    Enhancement algorithms for wireless acoustics sensor networks~(WASNs) are indispensable with the increasing availability and usage of connected devices with microphones. Conventional spatial filtering approaches for enhancement in WASNs approximate quantization noise with an additive Gaussian distribution, which limits performance due to the non-linear nature of quantization noise at lower bitrates. In this work, we propose a postfilter for enhancement based on Bayesian statistics to obtain a multidevice signal estimate, which explicitly models the quantization noise. Our experiments using PSNR, PESQ and MUSHRA scores demonstrate that the proposed postfilter can be used to enhance signal quality in ad-hoc sensor networks

    Recombinant Escherichia coli produces tailor-made biopolyester granules for applications in fluorescence activated cell sorting: functional display of the mouse interleukin-2 and myelin oligodendrocyte glycoprotein

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    BACKGROUND: Fluorescence activated cell sorting (FACS) is a powerful technique for the qualitative and quantitative detection of biomolecules used widely in both basic research and clinical diagnostic applications. Beads displaying a specific antigen are used to bind antibodies which are then fluorescently labelled using secondary antibodies. As the individual suspension bead passes through the sensing region of the FACS machine, fluorescent signals are acquired and analysed. Currently, antigens are tediously purified and chemically cross-linked to preformed beads. Purification and coupling of proteins often renders them inactive and they will not be displayed in its native configuration. As an alternative, we genetically engineered Escherichia coli to produce biopolyester (polyhdroxyalkanoate=PHA) granules displaying diagnostically relevant antigens in their native conformation and suitable for FACS analysis. RESULTS: Hybrid genes were constructed, which encode either the mouse interleukin-2 (IL2) or the myelin oligodendrocyte glycoprotein (MOG) fused via an enterokinase site providing linker region to the C terminus of the PHA granule associated protein PhaP, respectively. The hybrid genes were expressed in PHA-accumulating recombinant E. coli. MOG and IL2 fusion proteins were abundantly attached to PHA granules and were identified by MALDI-TOF/MS analysis and N terminal sequencing. A more abundant second fusion protein of either MOG or IL2 resulted from an additional N terminal fusion, which did surprisingly not interfere with attachment to PHA granule. PHA granules displaying either IL2 or MOG were used for FACS using monoclonal anti-IL2 or anti-MOG antibodies conjugated to a fluorescent dye. FACS analysis showed significant and specific binding of respective antibodies. Enterokinase treatment of IL2 displaying PHA granules enabled removal of IL2 as monitored by FACS analysis. Mice were immunized with either MOG or OVA (ovalbumin) and the respective sera were analysed using MOG-displaying PHA granules and FACS analysis showing a specific and sensitive detection of antigen-specific antibodies within a wide dynamic range. CONCLUSION: E. coli can be genetically engineered to produce PHA granules displaying correctly folded eukaryotic proteins and which can be applied as beads in FACS based diagnostics. Since PHA granule formation and protein attachment occurs in one step already inside the bacterial cell, microbial production could be a cheap and efficient alternative to commercial beads

    Two sides of breastfeeding support: experiences of women and midwives

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    <p>Abstract</p> <p>Background</p> <p>Midwives' support of breastfeeding in maternity wards has been proven to provide an impact on women's breastfeeding experiences. In previous studies women describe professional support unfavourably, with an emphasis on time pressures, lack of availability or guidance, promotion of unhelpful practices, and conflicting advice. Thus, the present study aims to investigate women's experiences and reflections of receiving breastfeeding support and midwives' experiences and reflections of giving breastfeeding support.</p> <p>Methods</p> <p>This study was carried out in a county in southwestern Sweden during 2003-2004. A qualitative method, content analysis, was chosen for the study. The data came from interviews with women as well as interviews with midwives who were experienced in breastfeeding support.</p> <p>Results</p> <p>The women's and midwives' experiences and reflections of receiving and giving breastfeeding support were conceptualized as one main theme: <it>"Individualized breastfeeding support increases confidence and satisfaction." </it>This theme contained three categories: "<it>The unique woman," </it><it>"The sensitive confirming process</it>," and <it>"Consistency of ongoing support." </it>In order to feel confident in their new motherhood role, the women wanted more confirmation as unique individuals and as breastfeeding women; they wanted to be listened to; and they wanted more time, understanding, and follow-up from health professionals. In contrast, the midwives described themselves as encouraging and confirming of the women's needs.</p> <p>Conclusions</p> <p>If health care professionals responded to the woman's unique needs, the woman felt that the breastfeeding support was good and was based on her as an individual, otherwise a feeling of uncertainty emerged. The midwives, however, expressed that they gave the women individual support, but they also expressed that the support came from different points of view, because the midwives interpreted women's signals differently.</p

    Elucidating recent history by tracing genetic affinity of three 16th century miners from Sweden.

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    Objectives: Sala Silver Mine in central Sweden was an important manufacturer of silver from at least the 16th till the early 20th century, with production peaking in the 16th, mid 17th and 19th centuries. The job opportunities offered by the mine attracted people to the area resulting in the development of a small township with an associated cemetery in the vicinity of the mining center. People affiliated to the mine were buried on the cemetery for around 150 years. Written sources reveal that common criminal convicts from Sweden-Finland and war prisoners from the numerous wars fought by Sweden during the time were exploited in the mine, and some of them were likely buried on the cemetery. The cemetery has been excavated on several occasions and the recovered human remains were divided into two different groups based on burial custom, demography and biochemical results. One group was believed to contain war prisoners; the aim of this study was to produce and interpret genomic data from these individuals to test if their genetic ancestry is consistent with the hypothesis that they were non-locals. Materials: Teeth from seven different individuals were sampled for dentine. Results: Three of the analyzed teeth contained sufficient amounts of endogenous human DNA for the generation of genomic sequence data to a coverage of 0.04, 0.19 and 0.83, respectively. Discussion: The results show that despite seeming heterogeneity the three individuals grouped within the range of genetic variation of modern and contemporary Swedes, yielding no statistical support to the hypothesis that they were foreign captives. However, due to the lack of contemporary or modern Danish genomic data we cannot refute these individuals originated in Denmark which was suggested as one of possible sources of the 17th century Swedish prisoners of war

    Nitrogen cycle disruption through the application of de-icing salts on upland highways

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    It is hypothesized that episodic introductions of road salt severely disrupt the soil nitrogen cycle at a range of spatial and temporal scales. A field-scale study has confirmed impacts on the nitrogen cycle in soil, soil solution and river samples. There is evidence that ammonium-N retention on cation exchange sites has been reduced by the presence of sodium ions, and that ammonium-N has been flushed from the exchange sites. Increases in soil pH have been caused in naturally acidic uplands. These have enhanced mineralization of organic-N, especially nitrification, leading to a reduction in the mineralizable-N pool of roadside soils. There is evidence to support the hypothesis that organic matter content has been lowered over decades either through desorption or dispersal processes. Multiple drivers are identified that contribute to the disruption of nitrogen cycling processes, but their relative importance is difficult to quantify unequivocally. The influence of road salt on soil and soil solution declines with distance from the highway, but impacts on water chemistry in a local stream are still strongly evident at some distance from the road

    Segundas geraçÔes de cabo-verdianos na Europa: reforçando os laços com o país ancestral

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    Este estudo tem como pĂșblico-alvo as segundas geraçÔes de Cabo-verdianos em Portugal, Holanda, ItĂĄlia e França e visa analisar o reforço de seus laços com Cabo Verde. O estudo Ă© de carĂĄter exploratĂłrio, qualitativo e teoricamente ligado Ă  integração, transnacionalismo, assimilação segmentada, identificação Ă©tnica e laços com o paĂ­s ancestral. Os resultados obtidos quanto Ă s relaçÔes com Cabo Verde permitem-nos identificar trĂȘs grupos: o primeiro adota um sincretismo cultural; o segundo vai a Cabo Verde praticamente sĂł para passar fĂ©rias e se divertir; o terceiro demonstra um ‘sentimento de pertença’ para com o paĂ­s ancestral e jĂĄ conseguiu alcançar maiores nĂ­veis de formação e percurso profissional. TambĂ©m demonstra muito maior interesse em contribuir para o desenvolvimento de Cabo Verde.This study has as target audience the second-generation of Cape Verdeans in Portugal, The Netherlands, Italy and France and aims to analyse the strengthening of their ties with Cape Verde. The study is exploratory, qualitative and theoretically linked to integration, transnationalism, segmented assimilation, ethnic identification and ties with their ancestral land. The results obtained regarding such relationships allow us to identify the following three groups: the first adopts a cultural syncretism; the second visits Cape Verde primarily for holidays and fun; the third demonstrates a ‘sense of Belonging’ towards their ancestral land and has achieved also much higher levels of education and professional career. It shows also much more interest to contribute to the development of Cape Verde.info:eu-repo/semantics/publishedVersio

    Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden

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    We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the ÎŽ13C and ÎŽ15N values for animal references from VĂ€sterĂ„s. This research (BĂ€ckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD
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