340 research outputs found

    ”I was meant to be able to do this”: women’s experiences of breastfeeding. A phenomenological study

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    Introduction. There is strong evidence demonstrating that human breastmilk provides complete nutrition for human infants. While the rate of initiation of breastfeeding in the UK has increased steadily over the last 25 years, rates of exclusive breastfeeding in the early weeks and months over the same time period have shown only marginal increases. Method. An interpretive phenomenological approach informed by the philosophy of Martin Heidegger was adopted. The aim was to understand women’s experience of breastfeeding. Women were recruited from one city in the East Midlands in the UK, where the prevalence of breastfeeding is decreasing. Potential participants were recruited via health visitors at the primary birth visit. Ethical approval was received from the university and NHS research ethics committees. Data were collected between three and six months after the birth of their youngest child and analysis was guided by interpretive phenomenological principles. Findings. The women were found to be ill-prepared for the realities of breastfeeding and, for most women, the shock of this experience was overwhelming. In particular there was a lack of understanding and preparation for common problems and a lack of awareness of newborn behaviour. Misunderstandings of newborn behaviour resulted in the women blaming infantfeeding behaviours, such as crying, wakeful states and cluster feeding, on the specific method of infant-feeding. Frequent feeding cues were overwhelming and the women felt overawed by the sense of responsibility. It also led them to question their ability to provide an adequate milk supply. Discussion. The extent to which inadequate preparation for breastfeeding had a negative impact on the breastfeeding experiences of women in this study was a surprise. Antenatal education should focus more on preparing women for the realities. Education and support for breastfeeding women need to encompass infant-feeding cues and infant behaviours

    Effect of yarn hairiness on energy consumption in rotating a ring-spun yarn package

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    The effect of yarn hairiness on energy consumption when rotating a ring-spun yarn package is investigated theoretically and experimentally. A theoretical model is developed to calculate the energy required to rotate hair fibers, based on hair length and number as well as package speed and size. A single spindle test rig is used to verify the theoretical prediction. The experimental results confirm the theoretical prediction that the package power increases with increased yarn hairiness level and spindle speed

    A review of the relationship between eggshell colour and water vapour conductance

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    This review brings together the available literature that examines the effect of variations in pigmentation on the gas conductance of avian eggshells. Pheasant and Houbara bustard eggs provide some evidence that shell abnormalities can impact upon colour and conductance. By contrast, data from wild birds suggest that neither the degree of maculation or intensity of ground colour impact upon gas conductance. Those studies that purport to show variation in rates of water loss in eggs with different degrees of pigmentation may have been confounded by variation in nest humidity. This emerging field of research remains very much in its infancy

    Flow interactions with an aquatic macrophyte: a field study using stereoscopic particle image velocimetry

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    This paper reports the morphology of a natural patch of Ranunculus penicillatus and presents high-resolution measurements of flow velocities in its wake using a stereoscopic PIV field measurement system. The patch was 3.80 m long, 1.24 m wide and caused substantial changes to downstream mean velocities and turbulence. Vertical profiles of streamwise mean velocity were not logarithmic and flow was redirected under the positively buoyant canopy, enhancing vertical turbulent mixing in the wake and generating a large region where the velocity covariance u'w' was positive. Turbulent kinetic energy was enhanced downstream from the patch lateral shear layer, but not at the centre of the wake. Spectra downstream from the patch showed that turbulence was neither dominated by fine-scale nor large-scale structures, likely due to the low energy of the flow conditions and lack of a developed vortex street within the measurement domain. Sedimentation was observed at the upstream end of the patch, but not underneath the floating canopy. The methods and results of this work will be useful for planning other in situ studies. Also, the reported data on macrophyte geometry and biometrics will assist with the design of more realistic replicas for use in laboratory studies

    Model-Based Filtering of Combinatorial Test Suites

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    International audienceTobias is a combinatorial test generation tool which can efficiently generate a large number of test cases by unfolding a test pattern and computing all combinations of parameters. In this paper, we first propose a model-based testing approach where Tobias test cases are first run on an executable UML/OCL specification. This animation of test cases on a model allows to filter out invalid test sequences produced by blind enumeration, typically the ones which violate the pre-conditions of operations, and to provide an oracle for the valid ones. We then introduce recent extensions of the Tobias tool which support an incremental unfolding and filtering process, and its associated toolset. This allows to address explosive test patterns featuring a large number of invalid test cases, and only a small number of valid ones. For instance, these new constructs could mandate test cases to satisfy a given predicate at some point or to follow a given behavior. The early detection of invalid test cases improves the calculation time of the whole generation and execution process, and helps fighting combinatorial explosion

    Optimization of inhomogeneous electron correlation factors in periodic solids

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    A method is presented for the optimization of one-body and inhomogeneous two-body terms in correlated electronic wave functions of Jastrow-Slater type. The most general form of inhomogeneous correlation term which is compatible with crystal symmetry is used and the energy is minimized with respect to all parameters using a rapidly convergent iterative approach, based on Monte Carlo sampling of the energy and fitting energy fluctuations. The energy minimization is performed exactly within statistical sampling error for the energy derivatives and the resulting one- and two-body terms of the wave function are found to be well-determined. The largest calculations performed require the optimization of over 3000 parameters. The inhomogeneous two-electron correlation terms are calculated for diamond and rhombohedral graphite. The optimal terms in diamond are found to be approximately homogeneous and isotropic over all ranges of electron separation, but exhibit some inhomogeneity at short- and intermediate-range, whereas those in graphite are found to be homogeneous at short-range, but inhomogeneous and anisotropic at intermediate- and long-range electron separation.Comment: 23 pages, 15 figures, 1 table, REVTeX4, submitted to PR

    Longitudinal effects of environmental enrichment on behaviour and physiology of pigs reared on an intensive-stock farm

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    The aim of this paper was to provide a longitudinal evaluation of the effects of physical enrichments on the behaviour and physiology of intensive stock-farming pigs. Twenty-eight crossbred pigs of both sexes, were exposed to four types of enrichments (hemp ropes, steel chains, plastic balls, rubber hoses) over a period of eleven weeks. This investigation was based on specific abnormal behaviours and physiological indicators, including hematologic parameters. For behavioural score, focal sampling was used with recording of abnormal behaviours (body-, tail- and ear-biting), belly nosing, running, and interaction with objects (for Enriched pigs). The presence of skin injuries was also recorded. In general, the frequency of abnormal behaviours was significantly reduced in the Enriched group. A timerelated profile appeared in the use of the enrichments. Males showed higher occurrence of skin injuries than females. Physiological measurements, such as levels of complement system, white blood cells and neutrophils, were lower in pigs from the Enriched group. Enriched pigs, as a whole, presented much lower levels of serum DHEA-S concentration over two weeks. The findings of this study show the successful provision of appropriate enrichments to encourage behaviours which may result in satisfactory animal oral interaction with the enriching objects, preventing them biting pen-mates. In this respect, the objects proposed were strongly effective in producing changes in behaviour which could mitigate inadequate conditions, such as the relationship between animal body weight and the available space allowance
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