Influence of airfoil geometry on delta wing leading-edge vortices and vortex-induced aerodynamics at supersonic speeds

An assessment of the influence of airfoil geometry on delta wing leading edge vortex flow and vortex induced aerodynamics at supersonic speeds is discussed. A series of delta wing wind tunnel models were tested over a Mach number range from 1.7 to 2.0. The model geometric variables included leading edge sweep and airfoil shape. Surface pressure data, vapor screen, and oil flow photograph data were taken to evaluate the complex structure of the vortices and shocks on the family of wings tested. The data show that airfoil shape has a significant impact on the wing upper surface flow structure and pressure distribution, but has a minimal impact on the integrated upper surface pressure increments

Alteration of Neutrophil Function in BCG-Treated and Non-Treated Swine after Exposure to Salmonella typhimurium

Salmonella typhimurium infection in swine causes an enterocolitis followed by a persistent carrier state, but little is known about the mechanisms that allow this organism to colonize and persist in host tissues. Neutrophils provide a first line of defense against invading pathogens such as Salmonella typhimurium. The purpose of this study was to evaluate porcine neutrophil function after in vivo exposure to Salmonella and to determine if the immunomodulator, bacillus Calmette Guerin (BCG), exerts any effect on neutrophil function or on the colonization and persistence of S. typhimurium in the pig. Compared to negative controls, neutrophils from pigs exposed to S. typhimurium exhibited significantly decreased iodination, cytochrome-C reduction, antibody-dependent cell-mediated cytotoxicity, random migration, and chemotaxis (P≤0.05). Neutrophil bactericidal activity against S. typhimurium was significantly enhanced. Most of the significant differences were noted in the first two days after exposure to Salmonella. Often the functional alterations were biphasic, peaking again 7–10 days after exposure. BCG alone significantly depressed random migration and cytochrome-C reduction in unstimulated neutrophils. The clinical course, colonization pattern, and persistence of Salmonella were similar between pigs receiving BCG and untreated pigs. These data suggest that S. typhimurium infection causes a depression in oxidative metabolism and motility, yet an increase in overall bactericidal activity against S. typhimurium in circulating porcine neutrophils. It also appears that BCG treatment, as reported here, does not enhance resistance of pigs to S. typhimurium colonization or reduce the number of persistent organisms in the porcine ileum

In Vivo Effects of a Thymosin a1-Containing Colostral Whey Product on N eutrophils and Lymphocytes from Lactating Cows Without and With Experimentally Induced Staphylococcus aureus Mastitis

Two separate experiments evaluated ID-1 (a commercial bovine whey product containing 5200 pg of thymosin α1/ml) as an immunotherapeutic agent in lactating cows. In the first experiment, cows without mastitis were evaluated for blood leukogram, milk production, total and differential milk cell counts, lymphocyte (Lc) blastogenesis, and neutrophil (PMN) functions (random and directed migration under agarose, chemiluminescence, ingestion of bacteria, iodination, cytochrome C reduction, antibody-independent neutrophil-mediated cytotoxicity, and antibody-dependent cell-mediated cytotoxicity) before and after ID-1 therapy. ID-1 treatment resulted in a significant treatment group by time period interaction for the relative proportion of mononuclear cells (MNC) in milk (P\u3c0.009) and for PMN random migration (P\u3c0.01). Based on these interactions, ID-1 treatment appeared to slightly increase the proportion of small MNC in milk and to increase random migration from pretreatment levels by 73% more than increases observed in controls. No significant effect of ID-1 treatment on milk production, total milk somatic cell counts, Lc blastogenesis, or other PMN functions was observed. In cows with experimental Staphylococcus aureus intramammary infections, ID-1 treatment resulted in a significant decline in blood leukocyte count (P\u3c0.001) and blood PMN count (P\u3c0.02), and maintained PMN random migration (P\u3c0.01) while controls declined and abrogated a depression in the ability of Lc to respond to mitogens (P\u3c0.05) that developed in controls as a result of S. aureus mastitis. Injection of ID-1 into cows had no adverse effect on their overall health or level of milk production, but did cause subtle and potentially favorable changes in several in vitro immune parameters. In spite of these subtle changes which might indicate increased resistance to mastitis, cows actually developed a more severe S. aureus intramammary infection based on a 9% increase in log10 bacterial shedding in milk

Ultrasound based technology for removal of scale from downhole production tubing, an experimental verification

Open Access via the Elsevier Agreement The authors are grateful to the Net Zero Technology Center (NZTC) and University of Aberdeen UK, for providing the laboratory facilities required to complete this research.Peer reviewe

Persistence of Multiple Paramyxoviruses in a Closed Captive Colony of Fruit Bats (Eidolon helvum).

Bats have been identified as the natural hosts of several emerging zoonotic viruses, including paramyxoviruses, such as Hendra and Nipah viruses, that can cause fatal disease in humans. Recently, African fruit bats with populations that roost in or near urban areas have been shown to harbour a great diversity of paramyxoviruses, posing potential spillover risks to public health. Understanding the circulation of these viruses in their reservoir populations is essential to predict and prevent future emerging diseases. Here, we identify a high incidence of multiple paramyxoviruses in urine samples collected from a closed captive colony of circa 115 straw-coloured fruit bats (Eidolon helvum). The sequences detected have high nucleotide identities with those derived from free ranging African fruit bats and form phylogenetic clusters with the Henipavirus genus, Pararubulavirus genus and other unclassified paramyxoviruses. As this colony had been closed for 5 years prior to this study, these results indicate that within-host paramyxoviral persistence underlies the role of bats as reservoirs of these viruses.This research was funded by Research England, the Royal Veterinary College, the Medical Research Council (grant number MR/P025226/1) and the Defense Advanced Research Projects Agency (DARPA) administered through Cooperative Agreement #D18AC00031-PREEMPT. JLNW and OR are funded by The Alborada Trust. AAC was part-funded by a Royal Society Wolfson Research Merit award

Where are the horses? With the sheep or cows? Uncertain host location, vector-feeding preferences and the risk of African horse sickness transmission in Great Britain

Understanding the influence of non-susceptible hosts on vector-borne disease transmission is an important epidemiological problem. However, investigation of its impact can be complicated by uncertainty in the location of the hosts. Estimating the risk of transmission of African horse sickness (AHS) in Great Britain (GB), a virus transmitted by Culicoides biting midges, provides an insightful example because: (i) the patterns of risk are expected to be influenced by the presence of non-susceptible vertebrate hosts (cattle and sheep) and (ii) incomplete information on the spatial distribution of horses is available because the GB National Equine Database records owner, rather than horse, locations. Here, we combine land-use data with available horse owner distributions and, using a Bayesian approach, infer a realistic distribution for the location of horses. We estimate the risk of an outbreak of AHS in GB, using the basic reproduction number (R0), and demonstrate that mapping owner addresses as a proxy for horse location significantly underestimates the risk. We clarify the role of non-susceptible vertebrate hosts by showing that the risk of disease in the presence of many hosts (susceptible and non-susceptible) can be ultimately reduced to two fundamental factors: first, the abundance of vectors and how this depends on host density, and, second, the differential feeding preference of vectors among animal species

Can insecticide-treated netting provide protection for Equids from Culicoides biting midges in the United Kingdom?

BACKGROUND: Biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) cause a significant biting nuisance to equines and are responsible for the biological transmission of African horse sickness virus (AHSV). While currently restricted in distribution to sub-Saharan Africa, AHSV has a history of emergence into southern Europe and causes one of the most lethal diseases of horses and other species of Equidae. In the event of an outbreak of AHSV, the use of insecticide treated nets (ITNs) to screen equine accomodation is recommended by competent authorities including the Office International des Épizooties (OIE) in order to reduce vector-host contact. METHODS: Seven commercially avaliable pyrethroid insecticides and three repellent compounds, all of which are licensed for amateur use, were assessed in modified World Health Organization (WHO) cone bioassay trials in the laboratory using a colony line of Culicoides nubeculosus (Meigen), 1830. Two field trials were subsequently conducted to test the efficiency of treated net screens in preventing entry of Culicoides. RESULTS: A formulation of cypermethrin (0.15 % w/w) and pyrethrins (0.2 % w/w) (Tri-Tec 14®, LS Sales (Farnham) Ltd, Bloxham, UK) applied to black polyvinyl-coated polyester insect screen (1.6 mm aperture; 1.6 mm thickness) inflicted 100 % mortality on batches of C. nubeculosus following a three minute exposure in the WHO cone bioassays at 1, 7 and 14 days post-treatment. Tri-Tec 14® outperformed all other treatments tested and was subsequently selected for use in field trials. The first trial demonstrated that treated screens placed around an ultraviolet light-suction trap entirely prevented Culicoides being collected, despite their collection in identical traps with untreated screening or no screening. The second field trial examined entry of Culicoides into stables containing horses and found that while the insecticide treated screens reduced entry substantially, there was still a small risk of exposure to biting. CONCLUSIONS: Screened stables can be utilised as part of an integrated control program in the event of an AHSV outbreak in order to reduce vector-host contact and may also be applicable to protection of horses from Culicoides during transport.The work of LEH and GLI was supported by funding from the Horserace Betting Levy Board (HBLB) (Vet/PRJ/766); TR was supported by funding from the University of Surrey; and JW was supported by the Alborada Trust and by the European Union FP7 project ANTIGONE (contract number 278976). RN is supported through a combined contribution to the Animal Health Trust’s Equine Infectious Disease Service from the HBLB, the Racehorse Owners’ Association (ROA) and the Thoroughbred Breeders’ Association (TBA). The Pirbright Institute receives grant aided support from the Biotechnology and Biological Sciences Research Council of the United Kingdom.This is the final version of the article. It was first available from BioMed Central via http://dx.doi.org/10.1186/s13071-015-1182-

Antibodies against Lagos Bat Virus in Megachiroptera from West Africa

To investigate the presence of Lagos bat virus (LBV)–specific antibodies in megachiroptera from West Africa, we conducted fluorescent antibody virus neutralization tests. Neutralizing antibodies were detected in Eidolon helvum (37%), Epomophorus gambianus (3%), and Epomops buettikoferi (33%, 2/6) from Ghana. These findings confirm the presence of LBV in West Africa