263 research outputs found
Natural solution to antibiotic resistance: bacteriophages ‘The Living Drugs’
Antibiotics have been a panacea in animal husbandry as well as in human therapy for decades. The huge amount of antibiotics used to induce the growth and protect the health of farm animals has lead to the evolution of bacteria that are resistant to the drug’s effects. Today, many researchers are working with bacteriophages (phages) as an alternative to antibiotics in the control of pathogens for human therapy as well as prevention, biocontrol, and therapy in animal agriculture. Phage therapy and biocontrol have yet to fulfill their promise or potential, largely due to several key obstacles to their performance. Several suggestions are shared in order to point a direction for overcoming common obstacles in applied phage technology. The key to successful use of phages in modern scientific, farm, food processing and clinical applications is to understand the common obstacles as well as best practices and to develop answers that work in harmony with nature
Effect of tail docking in Awassi lambs on metabolizable energy requirements and chemical composition of carcasses
The effect of tail docking on metabolizable energy requirements and carcass characteristics was studied using 80 weaned entire Awassi male lambs. Docking was performed within 3 days of birth and lambs were weaned at 90 days old. Docked and undocked lambs were randomly allocated to four groups, individually penned and offered different amounts of a pelleted concentrate diet. The pelleted diet was estimated to contain 11.8 MJ of metabolizable energy (ME) and 182 g of crude protein (CP) per kg dry matter (DM). Lambs on the high levels of intake were slaughtered at a target weight of approximately 45 kg. Other lambs were maintained on the diet for 149 days before being slaughtered. The right sides of all carcasses were cut into standardized commercial cuts then dissected into muscle, fat and bone. The soft tissue was pooled and analysed for DM, CP, ash and fat. Prediction of live-weight gain (LWG) and empty body gain for a given ME intake (MEI) was made using the growth and MEI data. MEI was expressed as MJ per kg metabolic body weight (M 0.75) per day. Tail docking had no effect (P> 0.05) on lamb growth from birth to weaning. During the post-weaning growth period, LWG and empty body gain were significantly higher (P 0.05) at high levels of intakes (between 0.74 and 1.1 MJ/kg M 0.75 per day). Hot and cold carcass weights were similar (P > 0.05) for the two groups. Differences in empty body weight and fleece-free empty body weight were significant (P 0.05) on food conversion efficiency (FCE). Carcasses from docked lambs had significantly lower (P 0.05) ash content
The Effect of Basal Diet on Lactate-Producing Bacteria and the Susceptibility of Sheep to Lactic Acidosis
The influence of a diet of either pasture or hay on the development of lactic acidosis in sheep was investigated using a grain challenge approach. Twenty-four Merino wethers with a mean live weight of 36.7 (s.e. 3.6) kg were used; 12 were adapted to grass pasture and 12 to hay (lucerne and oaten hay, 60 : 40) for 4 weeks before being given 1 kg of crushed barley via stomach tube. Six sheep in each group were also given virginiamycin (VM; 50 mg/kg barley) with the grain to test the efficacy of this antibiotic in controlling the bacteria responsible for the development of acidosis. Changes in volatile fatty acid (VFA), pH, lactate and bacterial count in the rumen and faecal pH and dry matter (DM) were measured for a 24-h period following administration of the barley. Daily intakes of hay were measured for a 10-day period following grain engorgement. Total ruminal VFA increased (P < 0.01) over time and tended (P = 0.08) to be higher in sheep adapted to hay than in those adapted to pasture (67.5 v. 59.8 mmol/l). The molar proportions of VFA changed (P< 0.01) over time in favour of propionate in both groups. Ruminal pH was higher (P< 0.001) in pasture-adapted sheep, but declined (P< 0.001) in both groups over time following the introduction of barley. This decline in pH was associated with increases in ruminal concentration of VFA in pasture-adapted sheep and VFA and lactate in hay-adapted sheep. The addition of VM resulted in a higher (P < 0.001) proportion of propionate and a trend towards higher (P = 0.24) faecal pH and DM content. Faecal pH and DM content declined (P < 0.001) over time and was lower for the pasture-adapted sheep. The introduction of either barley alone or barley with VM from both hay and pasture diets increased (P < 0.05) the viable counts of total bacteria, Streptococcus bovis and lactic acid bacteria. Bacterial isolates were purified and identified by complete sequencing of the 16S rRNA gene to determine the predominant bacteria during the overfeeding of grain. Isolates from medium selective for S. bovis were all identified as this species when VM was not given. VM had no effect on counts of viable bacteria, but inhibited the growth of S. bovis
Lacking the floor of the mouth: a case study on Coptodon zillii (Cichlidae) from Shatt Al-Arab River, Basrah, Iraq
A single case of double mouth monstrosity was observed and examined in the cichlid fish Coptodon zillii collected from Shatt Al-Arab River, Basrah, Iraq on 15 May 2018. Instead, add the followings,"The floor of the mouth was ruptured, creating an extra mouth opening beneath the normal mouth. An injury may have caused this condition. Morphological examination indicates that the fish had lived with the abnormality for some time
Macroscopic study of syrinx in the common bulbul (Pycnontus barbatus) and indigenous pigeon (Columba domestica)
In this study, syrinx of five male common bulbuls (Pycnontus barbatus) weighing (25.93 ±0.89 g) and five male indigenous pigeons (Columba domestica) weighing (286±0.73 g) were examined for macroscopic structure. The results showed the anatomical positions of the syrinx. The syrinx was observed ventral to the esophagus exactly on the base of heart in the common bulbul, whilst in pigeon; the syrinx was hidden by the heart. The morphological structure of the syrinx in both species could be classified as tracheobronchial type. The number of tracheo-syringeal rings could not be determined certainly in common bulbul, while in the pigeon, tracheo-syringeal part was composed of the two cartilaginous rings (T1 and T2). These two cartilaginous rings were different in diameters and joined each other at the middle. In the common bulbul, tympanum which is the middle part of syrinx has the bilateral bulla; while tympanum of pigeon does not have bulla. Furthermore, the broncho-syringeal cartilages from the caudal part of a syrinx, which is composed of five C-shaped rings in both species. The caudal syringeal part of common bulbul has intrabronchial foramen, which absents in a pigeon
Changes in air quality associated with mobility trends and meteorological conditions during COVID-19 lockdown in Northern England, UK
The COVID-19 pandemic triggered catastrophic impacts on human life, but at the same time demonstrated positive impacts on air quality. In this study, the impact of COVID-19 lockdown interventions on five major air pollutants during the pre-lockdown, lockdown, and post-lockdown periods is analysed in three urban areas in Northern England: Leeds, Sheffield, and Manchester. A Generalised Additive Model (GAM) was implemented to eliminate the effects of meteorological factors from air quality to understand the variations in air pollutant levels exclusively caused by reductions in emissions. Comparison of lockdown with pre-lockdown period exhibited noticeable reductions in concentrations of NO (56.68–74.16%), NO2 (18.06–47.15%), and NOx (35.81–56.52%) for measured data. However, PM10 and PM2.5 levels demonstrated positive gain during lockdown ranging from 21.96–62.00% and 36.24–80.31%, respectively. Comparison of lockdown period with the equivalent period in 2019 also showed reductions in air pollutant concentrations, ranging 43.31–69.75% for NO, 41.52–62.99% for NOx, 37.13–55.54% for NO2, 2.36–19.02% for PM10, and 29.93–40.26% for PM2.5. Back trajectory analysis was performed to show the air mass origin during the pre-lockdown and lockdown periods. Further, the analysis showed a positive association of mobility data with gaseous pollutants and a negative correlation with particulate matter
Industry-relevant implicit large-eddy simulation of a high-performance road car via spectral/HP element methods
This is the author accepted manuscript. The final version is available from the Society for Industrial and Applied Mathematics via the DOI in this recordWe present a successful deployment of high-fidelity Large-Eddy Simulation (LES)
technologies based on spectral/hp element methods to industrial flow problems, which are characterized by high Reynolds numbers and complex geometries. In particular, we describe the numerical
methods, software development and steps that were required to perform the implicit LES of a real
automotive car, namely the Elemental Rp1 model. To the best of the authors’ knowledge, this simulation represents the first high-order accurate transient LES of an entire real car geometry. Moreover,
this constitutes a key milestone towards considerably expanding the computational design envelope
currently allowed in industry, where steady-state modelling remains the standard. To this end, a
number of novel developments had to be made in order to overcome obstacles in mesh generation
and solver technology to achieve this simulation, which we detail in this paper. The main objective
is to present to the industrial and applied mathematics community, a viable pathway to translate
academic developments into industrial tools, that can substantially advance the analysis and design
capabilities of high-end engineering stakeholders. The novel developments and results were achieved
using the academic-driven open-source framework Nektar++.Engineering and Physical Sciences Research Council (EPSRC)European Union Horizon 2020Imperial College High Performance Computing ServiceNational University of SingaporeAirbu
Prediction of Low-Voltage Tetrafluoromethane Emissions Based on the Operating Conditions of an Aluminium Electrolysis Cell
Greenhouse gas (GHG) generation is inherent in the production of aluminium by a technology that uses carbon anodes. Most of those GHG are composed of CO2 produced by redox reaction that occurs in the cell. However, a significant fraction of the annual GHG production is composed of perfluorocarbons (PFC) resulting from anode effects (AE). Multiple investigations have shown that
tetrafluoromethane (CF4) can be generated under low-voltage conditions in the electrolysis cells, without global anode effect. The aim of this paper is to find a quantitative relationship between monitored cell parameters and the emissions of CF4. To achieve this goal, a predictive algorithm has been developed using seven cell indicators. These indicators are based on the cell voltage, the noise level and other parameters calculated from individual anode current monitoring. The predictive algorithm is structured into three different
steps. The first two steps give qualitative information while the third one quantitatively describes the expected CF4 concentration at the duct end of the electrolysis cells. Validations after each step are presented and discussed. Finally, a sensitivity analysis was performed to understand the effect of each indicator on the onset of low-voltage PFC emissions. The standard deviation of
individual anode currents was found to be the dominant variable. Cell voltage, noise level, and maximum individual anode current also showed a significant
correlation with the presence of CF4 in the output gas of an electrolysis cell
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Cross-Sectional Conductive Atomic Force Microscopy of CdTe/CdS Solar Cells: Effects of Etching and Back-Contact Processes; Preprint
We investigated the effects of the etching processes using bromine and nitric-phosphoric acid solutions, as well as of Cu, in the bulk electrical conductivity of CdTe/CdS solar cells using conductive atomic force microscopy (C-AFM). Although the etching process can create a conductive layer on the surface of the CdTe, the layer is very shallow. In contrast, the addition of a thin layer of Cu to the surface creates a conductive layer inside the CdTe that is not uniform in depth, is concentrated at grains boundaries, and may short circuit the device if the CdTe is too thin. The etching process facilitates the Cu diffusion and results in thicker conductive layers. The existence of this inhomogeneous conductive layer directly affects the current transport and is probably the reason for needing thick CdTe in these devices
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