Acoustic energy transmission in cast iron pipelines

In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure

New method for the orthogonal labeling and purification of Toxoplasma gondii proteins while inside the host cell

oxoplasma gondii is an obligate intracellular protozoan parasite that is capable of causing severe disease in immunocompromised humans. How T. gondii is able to modulate the host cell to support itself is still poorly understood. Knowledge pertaining to the host-parasite interaction could be bolstered by developing a system to specifically label parasite proteins while the parasite grows inside the host cell. For this purpose, we have created a strain of T. gondii that expresses a mutant Escherichia coli methionyl-tRNA synthetase (MetRSNLL) that allows methionine tRNA to be loaded with the azide-containing methionine analog azidonorleucine (Anl). Anl-containing proteins are susceptible to a copper-catalyzed “click” reaction to attach affinity tags for purification or fluorescent tags for visualization. The MetRSNLL-Anl system labels nascent T. gondii proteins in an orthogonal fashion, labeling proteins only in MetRSNLL-expressing parasites. This system should be useful for nonradioactive pulse-chase studies and purification of nascently translated proteins. Although this approach allows labeling of a diverse array of parasite proteins, secreted parasite proteins appear to be only minimally labeled in MetRSNLL-expressing T. gondii. The minimal labeling of secreted proteins is likely a consequence of the selective charging of the initiator tRNA (and not the elongator methionine tRNA) by the heterologously expressed bacterial MetRS. IMPORTANCE Studying how T. gondii modifies the host cell to permit its survival is complicated by the complex protein environment of the host cell. The approach presented in this article provides the first method for specific labeling of T. gondii proteins while the parasite grows inside the host cell. We show that this approach is useful for pulse-chase labeling of parasite proteins during in vitro growth. It should also be applicable during in vivo infections and in other apicomplexan parasites, including Plasmodium spp

Investigating management strategies of large litters in pigs

Modern hyper-prolific sows often do not have enough teats to feed all of their piglets. The resulting competition for colostrum and milk hampers piglet growth and survival. This is exacerbated by low birth-weights, which are also common in large litters. Three experiments were conducted for this thesis; each investigated a management strategy hypothesised to improve outcomes for piglets from large litters. The first experiment evaluated the use of nurse sows to rear supernumerous piglets (i.e. when there are more piglets than teats). At 1 day old, piglets from large litters either remained with their mother or were moved to a nurse sow who was either 7 or 21 days into lactation. Aspects of piglet (growth, survival and suckling behaviour) and sow (salivary cortisol, back-fat thickness, body lesions, and nursing behaviour) welfare were monitored until weaning. Rearing by a nurse sow did not compromise pre-weaning survival, compared to rearing by the mother, regardless of the nurse sows’ stage of lactation (7 or 21 days) when the piglets were transferred to her. Piglets reared by a nurse sow were initially heavier than piglets remaining with their dam, but all piglets were weaned at similar weights. Regardless of whether a nurse sow or biological mother, sows in late lactation had shorter nursing bouts and their litter showed more fighting behaviour, compared to sows in early lactation. Despite longer lactation length, nurse sows did not differ from biological mothers in salivary cortisol concentration, backfat thickness and body lesion scores. The second experiment looked at using an artificial rearing system to rear 7 day old piglets until weaning. Litters of 12 piglets were assigned at 7 days old to be either sow-reared (SR) or artificially-reared (AR) until weaning. Pre-weaning survival, growth and behaviour were recorded, emotional state was assessed using Qualitative Behavioural Assessment pre- and post-weaning, and reactivity tests were conducted post-weaning. Survival did not differ between treatments. AR piglets were lighter than SR piglets from the day following transfer until weaning. They performed more negative behaviours (belly-nosing, ear and tail biting) and their emotional state was scored lower pre-weaning, compared to SR piglets. However, post-weaning the emotional state of AR piglets was scored higher than SR pigs and AR piglets had a lower emotional reaction to a fear test (startling event) and human contact. The third experiment evaluated whether 2ml of an energy-rich neonatal supplement (coconut oil or a commercial product) would enhance survival and vitality of low birth-weight piglets. At three hours post-birth, low birthweight piglets (<1.1 kg) were dosed with one of the supplements, water, or sham-dosed. Blood glucose content, rectal temperature, and pre-weaning survival and growth were recorded but none were affected by treatment. Post-weaning, piglets were tested for spatial learning and memory in a T-maze set-up, or were tested for short-term memory in a spontaneous object recognition test. There were no treatment differences on the performance of pigs in any of the two tests, meaning that the birth energy supplementation did not enhance post-weaning cognitive performances. This thesis demonstrated that a single dose of energy supplementation at birth did not improve outcomes for low birth-weight piglets, and that the rearing strategies to promote piglet survival in large litters do work in terms of survival but can impair some aspects of piglet welfare and development. The most pronounced welfare impacts were observed with artificial rearing. Therefore management of large litters remains a significant challenge and the strategies investigated deserve further improvements

Modelling phosphorus fluxes in Loweswater

1. This is the final report to the Loweswater Care Project (in support of the Catchment Restoration Fund for England) ECRC-ENSIS Project 298, 'Loweswater 12-13'. The study was concerned with the spatial and temporal concentrations of sediment phosphorus (P) in the lake and the use of P measurements from the water column and inflow and outflow samples to derive a simple mass balance model for P in the lake. 2. A review of published and unpublished literature on Loweswater highlighted trends in water chemistry since the mid-eighteenth century. Land use and farming practises have changed over the past 200 years which have led to increased nutrient loading to the lake with significant increases occurring in the mid part of the last century. Agricultural intensification is likely to be a significant cause of the problem as well as inadequate septic tank management. Local management efforts, led by the Loweswater Care Project, has sought to reduce the primary sources of nutrients reaching the lake, but total phosphorus (TP) concentrations in the lake remain higher than desired. 3. Temperature and dissolved oxygen (DO) profiling confirmed that the site stratified in summer with major changes in DO occurring below a depth of 8 m. The deeper waters were almost entirely anoxic. During stratification the maximum TP value was recorded at the lake bottom. This is a clear indication that P is being released from the lake bed during summer stratification. 4. Analysis of the stream water from the Dub Beck inflow (data for 2013), shows that P influx remains high enough to explain the elevated lake water P concentrations, despite considerable efforts to reduce catchment P sources. 5. Analysis of the water column P profiles shows that P release from the sediment is only a minor contribution to the P load. While the sediment core data reveals a substantial pool of P in the sediment very little of this should be released each year to the water column. In 2013 it is estimated that more than 90% of the P came from the catchment and only ~10% from the sediment. 6. As with all modelling exercises there are uncertainties inherent in the approach. In this case the model output is based on a single year of input data for the inflow P flux calculations and it would be preferable to have a longer data series to inform the modelling. Inflow fluxes are highly dependent on flow conditions and here, in the absence of flow data from Dub Beck, we used data from a nearby stream. Further, the monthly sampling has resulted in most samples being taken in low flow conditions, thus missing potential storm flow conditions. Finally, stream input information is restricted to Dub Beck, and contributions from the other stream is unknown. 7. Nevertheless, the results from the modelling are clear and on that basis we conclude that the priority is for P loading to the lake to be reduced by better catchment management and that lake manipulation is not warranted. Integrated catchment management supported by modelling together with local stakeholder engagement should provide the most effective means of improving the condition of the lake

Miniaturized wet-wet differential pressure sensor

We report a miniaturized wet-wet differential pressure sensor with applications in pressure and flow sensing in water networks and other harsh environments. The device is similar in concept to a conventional wet-wet differential pressure sensor in that the sensing element is protected from the external environment by oil-filled cavities closed off by corrugated diaphragms. However, with a package envelope of 11.0 x 4.8 x 3.4 mm 3 , corresponding to a volume of only 0.18 cm 3 , the device is considerably smaller than commercially available wet-wet differential pressure sensors. A high degree of miniaturization has been achieved by using micromachining to fabricate the corrugated diaphragms. Preliminary experimental results are presented showing operation of the device as a delta-pressure flow speed sensor in a water flow test rig

Birth data accessibility via primary care health records to classify health status in a multi-ethnic population of children: an observational study

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The feasibility of using pedometers and brief advice to increase activity in sedentary older women:a pilot study

Background: People over the age of 70 carry the greatest burden of chronic disease, disability and health care use. Participation in physical activity is crucial for health, and walking accounts for much of the physical activity undertaken by sedentary individuals. Pedometers are a useful motivational tool to encourage increased walking and they are cheap and easy to use. The aim of this pilot study was to evaluate the feasibility of the use of pedometers plus a theory-based intervention to assist sedentary older women to accumulate increasing amounts of physical activity, mainly through walking. Methods: Female participants over the age of 70 were recruited from primary care and randomised to receive either pedometer plus a theory-based intervention or a theory-based intervention alone. The theory-based intervention consisted of motivational techniques, goal-setting, barrier identification and self-monitoring with pedometers and daily diaries. The pedometer group were further randomised to one of three target groups: a 10%, 15% or 20% monthly increase in step count to assess the achievability and acceptability of a range of targets. The primary outcome was change in daily activity levels measured by accelerometry. Secondary outcome measures were lower limb function, health related quality of life, anxiety and depression. Results: 54 participants were recruited into the study, with an average age of 76. There were 9 drop outs, 45 completing the study. All participants in the pedometer group found the pedometers easy to use and there was good compliance with diary keeping (96% in the pedometer group and 83% in the theory-based intervention alone group). There was a strong correlation (0.78) between accelerometry and pedometer step counts i.e. indicating that walking was the main physical activity amongst participants. There was a greater increase in activity (accelerometry) amongst those in the 20% target pedometer group compared to the other groups, although not reaching statistical significance (p = 0.192). Conclusion: We have demonstrated that it is feasible to use pedometers and provide theory-based advice to community dwelling sedentary older women to increase physical activity levels and a larger study is planned to investigate this further.Publisher PDFPeer reviewe

Endogenous endophthalmitis caused by Pseudomonas aeruginosa in a preterm infant: a case report

Endophthalmitis is an infection of the vitreous or aqueous humor of the eye. Although it rarely occurs in the neonatal period it has been previously diagnosed in preterm infants