1,252 research outputs found

    The risk of rabies spread in Japan: a mathematical modeling assessment

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    Rabies was eliminated from Japan in 1957. In the 60 years since elimination, vaccination coverage has declined and dog ownership habits have changed. The purpose of this study was to assess the current risk of rabies spread in Japan. A spatially explicit transmission model was developed at the 1 km2 grid scale for Hokkaido and Ibaraki Prefectures. Parameters associated with dog movement and bite injuries were estimated using historical records from Japan, and were used with previously published epidemiological parameters. The final epidemic size, efficacy of rabies contingency plans and the influence of dog owner responses to incursions were assessed by the model. Average outbreak sizes for dog rabies were 3.1 and 4.7 dogs in Hokkaido and Ibaraki Prefectures, respectively. Average number of bite injury cases were 4.4 and 6.7 persons in Hokkaido and Ibaraki Prefectures, respectively. Discontinuation of mandatory vaccination increased outbreak sizes in these prefectures. Sensitivity analyses showed that higher chance of unintentional release of rabid dogs by their owners (from 0.5 to 0.9 probability) increased outbreak size twofolds. Our model outputs suggested that at present, incursions of rabies into Japan are very unlikely to cause large outbreaks. Critically, the reaction of dog owners to their dogs developing rabies considerably impacts the course of outbreaks. Contingency measures should therefore include sensitisation of dog owners

    The reports of questionnaire about the diagnosis and prevention of weak calf syndrome in calves

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    A questionnaire survey aiming to elucidate the perception among veterinarians on the association between diarrhea in calves and Weak Calf Syndrome (WCS) was conducted in Japan, and 248 veterinarians in 39 prefectures answered the questionnaire. Among the respondents, 85.5% belonged to NOSAI (Farmers’ Mutual Aid Association), 3.2% were independent veterinarians, 5.2% were herd management service veterinarians, and 6.5% answered others. Male were 83.5%, and female 16.5%. Questionnaire covered reasons of WCS, diagnosis and prevention, characteristics of well-managed farms with fewer cases of diarrhea, and collection of information on calf diarrhea. Regarding the contribution of WCS on diarrhea, 77.8% answered that the contribution is large or non-negligible, and 56.3% answered that the proportion of diarrhea with WCS is less than 5%, and 22.1% answered that the proportion is more than 10%. According to the cattle breeds which the veterinarian deals with mainly, the proportion of answering that WCS affects diarrhea greatly or non-negligibly was significantly higher among those who deal with Holstein (Hol, 64/92, 69.5%) breed than Japanese Black (JB, 91/110, 82.7%, x2 = 4.2, df = 1, p = 0.04). The most common two answers for the cause of WCS were pedigree and nutritional status at the late stage of pregnancy, and especially veterinarians of 40s and 50s age raised pedigree. Nutrition status at fetus stage, and history of colostrum feeding were second and third common answers. When the respondents are stratified by main breeds dealing with, both groups dealing with Hol and JB prioritized pedigree and nutritional status at the late stage of pregnancy. However, Hol group tended to raise accidents at delivery and infection in fetus, while JB group pedigree and nutrition at fetus stage, in the second place. Most common criterion of diagnosis with WCS was light body weight, and low vitality, weak suckling of colostrum followed, and as higher age, larger proportion answered light body weight. Most common counter major against WCS was nutrition management around delivery, which accounted more than 50%, and selection of pedigree at insemination and colostrum management followed. Common answers as the second rank were suckling and environmental hygiene management after delivery. Veterinarians chose hygiene, delivery - colostrum management, skill for observation, and feeding management commonly as characteristic of good practice farms with fewer diarrhea; however the proportions varied. For the same question, Hol group tended to answer delivery – colostrum management, while JB group feeding management. As shown above, the perception of WCS among veterinarians differed according to their age and the main cattle breeds dealing with

    A non-resonant RF cavity loaded with amorphous alloy for proton cancer therapy

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    A non-resonant RF cavity loaded with amorphous alloy cores has been designed and tested. The cavity has a re-entrant structure loaded with 8 amorphous alloy toroidal core and its characteristic impedance is designed as 450 Omega . The RF power is fed by 1 kW solid state amplifier using a step-up transformer with 1:9 impedance ratio. In the high power test, an accelerating gap voltage of more than 900 V was measured with input power of 1 kW in the frequency range of 1 to 10 MHz. The voltage standing wave ratio (VSWR) was less than 2.0. The results prove that the cavity may be used successfully within a compact proton synchrotron for a cancer therapy facility. (3 refs)

    Observation of a continuous phase transition in a shape-memory alloy

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    Elastic neutron-scattering, inelastic x-ray scattering, specific-heat, and pressure-dependent electrical transport measurements have been made on single crystals of AuZn and Au_{0.52}Zn_{0.48} above and below their martensitic transition temperatures (T_M=64K and 45K, respectively). In each composition, elastic neutron scattering detects new commensurate Bragg peaks (modulation) appearing at Q = (1.33,0.67,0) at temperatures corresponding to each sample's T_M. Although the new Bragg peaks appear in a discontinuous manner in the Au_{0.52}Zn_{0.48} sample, they appear in a continuous manner in AuZn. Surprising us, the temperature dependence of the AuZn Bragg peak intensity and the specific-heat jump near the transition temperature are in favorable accord with a mean-field approximation. A Landau-theory-based fit to the pressure dependence of the transition temperature suggests the presence of a critical endpoint in the AuZn phase diagram located at T_M*=2.7K and p*=3.1GPa, with a quantum saturation temperature \theta_s=48.3 +/- 3.7K.Comment: 6 figure

    Fermi Surface as a Driver for the Shape-Memory Effect in AuZn

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    Martensites are materials that undergo diffusionless, solid-state transitions. The martensitic transition yields properties that depend on the history of the material and may allow it to recover its previous shape after plastic deformation. This is known as the shape-memory effect (SME). We have succeeded in identifying the primary electronic mechanism responsible for the martensitic transition in the shape-memory alloy AuZn by using Fermi-surface measurements (de Haas-van Alphen oscillations) and band-structure calculations. This strongly suggests that electronic band structure is an important consideration in the design of future SME alloys

    Pharmacological Comparison of Human Internal Mammary Artery and Radial Artery in Terms of Conduits for Revascularization

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    Internal mammary arteries (IMA) are routinely used for coronary artery bypass grafting (CABG), but can exhibit impairment of endothelium-dependent vascular relaxation. The use of radial artery (RA) grafts for CABG has been recently reintroduced. The long-term patency of these grafts may depend on the ability of these vessels to produce endotheliumderived nitric oxide (NO). We therefore sought to determine if the RA exhibits better endothelial function compared with IMA harvested from the same patient. Using the organ bath technique, vessels were preconstricted with the thromboxane A2 analogue (U46619) and exposed to increasing concentrations of either acetylcholine (ACh ), calcium ionophore A23187 (A23187), or nitroglycerin (NTG). We prepared the rubbed RA for comparison of between RA with and without endothelium on response to ACh relaxation. KCI and U46619 constricted RA (11.3ツア4.9g and 16.0ツア4.3g respectively) more than IMA(2.4ツア1.4g and 4.5ツア1.7 respectively). Both RA and IMA relaxed 100% of the preconstricted tension to NTG. ACh induced less relaxation in the IMA(28ツア24%) when compared with the RA(49ツア16%)(p<0.05). A23187 demonstrated relaxation in both the RA(86ツア14%)and IMA(76ツア18%), but there was no statistical difference. RA without endothelium showed same response to ACh as IMAs. Compared with the IMA, the RA has better ACh induced endothelium-dependent relaxation. This pathway mainly involves NO production which also inhibits the atherosclerotic process. Therefore, the RA may provide longer term graft patency than IMA

    An estimation of thermophilic Campylobacter population in ready-to-eat roast beef and chicken sold and hygiene practices of sellers in beer bars in Arusha, Tanzania.

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    Background: In Tanzania, ‘nyama-choma’ (roast beef) and ‘kuku-choma’ (roast chicken) are popular ready-to-eat foods served in beer bars. A separate risk assessment for thermophilic Campylobacter in Arusha showed that the incidence rate was 6.4 people (90% CI: 3.4-10.4) per 1000 peopleper day but the concentration of Campylobacter in beef, which was not studied, was the factor influencing the results of the assessment the most. The present study was thus conducted to understand the concentration of thermophilic Campylobacter on roast beef and chicken surfaces as well as that on raw beef using the most probable number (MPN) approach. Methods: A survey was conducted in Arusha, Tanzania in September and October 2010 and 30 samples of beef sold at butchers and 30 samples of roast beef and 10 samples of roast chicken sold at nyama-choma beer bars were collected and these butchers and bar owners were interviewed for the sales and hygiene information. Fifty grams of samples were rinsed with 25 ml of Phosphate Buffered Saline (PBS) and one ml of each three replicates of this solution and 10 and 100 times diluted solutions were inoculated to Preston broth and incubated at 42°C for 24 hours in a CO2 jar. The solutions were then cultured on CCDA agar at 42°C for 48 hours and the isolates were sub-cultured on blood agar and the DNA was extracted. The extracted DNA was tested for thermophilic Campylobacter using PCR and positive DNA was tested for both C. jejuni and C. coli. The MPN of the isolates was obtained from the MPN table. Results: Out of 70 samples, thermophilic Campylobacter isolates were detected from one sample of roast chicken and identified as C. coli. The prevalence was therefore 0% (0/30) for beef at butchers, 0% (0/30) for roast beef and 10% (1/10) for roast chicken. The MPN of the C. coli was 0.37/g of meat (95% CI: 0.07 – 1.0). A low recovery rate and the small value of MPN might be due to dry and hot selling environment in butchers and heat of roasted meats. According to the interviews with 30 butchers, 7 respondents (23%) had a refrigerator and 16 (53%) had received hygiene training. Similarly, out of 40 nyama-choma beer bar owners where 30 roast beef and 10 roast chicken were sampled, 8 (20%) had a refrigerator and 21 (53%) had been trained. All the respondents used tap water in their operation. The fact that C. coli was recovered from roast chicken suggested possible post-roast contamination and although the owner of the bar which C. coli was detected did not use same utensils for both raw and roasted meat, 38% (15/40) of nyama-choma bar operators reported using. The proportions of pubs using the same utensils for both raw and roast meat were not significantly different between those trained for hygiene (7/21, 33%) and not trained (8/19, 42%, x2=0.06, df=1, p=0.81), suggesting ineffectiveness of hygiene training provided by the health authorities. Future research should focus on updating the risk assessment and incentives of compliance to hygiene regulation

    Stellar jitter from variable gravitational redshift: implications for RV confirmation of habitable exoplanets

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    A variation of gravitational redshift, arising from stellar radius fluctuations, will introduce astrophysical noise into radial velocity measurements by shifting the centroid of the observed spectral lines. Shifting the centroid does not necessarily introduce line asymmetries. This is fundamentally different from other types of stellar jitter so far identified, which do result from line asymmetries. Furthermore, only a very small change in stellar radius, ~0.01%, is necessary to generate a gravitational redshift variation large enough to mask or mimic an Earth-twin. We explore possible mechanisms for stellar radius fluctuations in low-mass stars. Convective inhibition due to varying magnetic field strengths and the Wilson depression of starspots are both found to induce substantial gravitational redshift variations. Finally, we investigate a possible method for monitoring/correcting this newly identified potential source of jitter and comment on its impact for future exoplanet searches.Comment: 6 pages, 1 figure, 1 tabl
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