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81.
OBJECTIVE: To evaluate the prevalence of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) in horses and horse personnel. DESIGN: Prospective prevalence study. SAMPLE POPULATION: 972 horses and 107 personnel from equine farms in Ontario, Canada and New York state. PROCEDURE: Nasal swab specimens were collected from horses and humans on farms with (targeted surveillance) and without (nontargeted surveillance) a history of MRSA colonization or infection in horses during the preceding year. Selective culture for MRSA was performed. Isolates were typed via pulsed-field gel electrophoresis, and antibiograms were determined. RESULTS: MRSA was isolated from 46 of 972 (4.7%) horses (0/581 via nontargeted surveillance and 46/391 [12%] via targeted surveillance). Similarly, MRSA was isolated from 14 of 107 (13%) humans (2/41 [5%] from nontargeted surveillance and 12/66 [18%] from targeted surveillance). All isolates were subtypes of Canadian epidemic MRSA-5, an uncommon strain in humans. All isolates were resistant to at least 1 antimicrobial class in addition to beta-lactams. On all farms with colonized horses, at least 1 human was colonized with an indistinguishable subtype. For horses, residing on a farm that housed > 20 horses was the only factor significantly associated with MRSA colonization. For humans, regular contact with > 20 horses was the only identified risk factor. CONCLUSIONS AND CLINICAL RELEVANCE: Results confirm a reservoir of colonized horses on a variety of farms in Ontario and New York and provide evidence that 1 MRSA strain is predominantly involved in MRSA colonization in horses and humans that work with horses.  相似文献   
82.
Analysis of data from the Infrared Astronomical Satellite has yielded evidence for narrow trails of dust coincident with the orbits of periodic comets Tempel 2, Encke, and Gunn. Dust was found both ahead of and behind the orbital positions of these comets. This dust was produced by the low-velocity ejection of large particles during perihelion passage. More than 100 additional dust trails are suggested by the data, almost all near the detection limits of the satellite. Many of these dust trails may be derived from previously unobserved comets.  相似文献   
83.
The performance of raw bagasse (RB), and tartaric acid-modified bagasse (TAMB) as adsorbents on decolorization and chemical oxygen demand (COD) reduction of methylene blue (MB) aqueous solution was studied. The effects of five factors namely: adsorbent dosage, pH, shaking speed, contact time, and temperature on decolorization and COD reduction were studied and optimized using central composite design (CCD). The results of the analysis show that all selected factors exhibit significant effect on decolorization and COD reduction. Maximum decolorization (78.16%) and COD reduction (77.95%) for RB was achieved at 0.82 g of adsorbent dosage, pH 9.4, 122 rpm of shaking speed, 44 min of contact time, and 55°C. For TAMB, maximum decolorization (99.05%) and COD reduction (98.45%) was achieved at 0.78 g adsorbent dosage, pH 9.4, shaking speed of 120 rpm, 34 min contact time, and 49°C. TAMB was found to be more effective than RB in decolorization and COD reduction of MB aqueous solution.  相似文献   
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G. R. Mackay  R. J. Low 《Euphytica》1975,24(2):525-529
Summary On screening samples of seed of commercial kale for spontaneous haploids, unexpectedly large numbers of triploid seeds were found in the small seed fractions. These are presumed to have arisen from unreduced gametes and may be similar in origin to diploid maternals, more usually obtained via interspecific pollination.  相似文献   
87.
A novel sorbent, chitosan-immobilized pumice, has been prepared for the sorption of As(V) from waters prior to its determination by hydride generation atomic absorption spectrometry. The success of the immobilization has been checked with such characterization techniques as scanning electron microscopy, thermal gravimetric analysis, and elemental analysis. Points of zero charge of the sorbents were determined with potentiometric mass titration. Batch-type equilibration studies have shown that the novel sorbent can be employed at a wide pH range resulting in quantitative sorption (>90 %) at pH 3.0–7.0 and greater than 70 % sorption at pH >8.0. These results demonstrate the advantage of immobilizing chitosan onto pumice, because, under the same conditions, pumice displays <20 % sorption toward As(V), whereas chitosan gives approximately 90 % sorption only at pH 3.0. The validity of the method was verified through the analysis of ultrapure, bottled drinking, and tap water samples spiked with arsenate; the respective sorption percentages of 93.2 (±0.7), 89.0 (±1.0), and 80.9 (±1.3) were obtained by batch-type equilibration. Arsenic sorption was also examined in the presence of common interfering ions resulting in competing effects of PO4 3? and NO3 ? on As(V) adsorption.  相似文献   
88.
The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth-the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.  相似文献   
89.
DDE, TDE, and polychlorinated biphenyls (PCBs) as Aroclors 1260 and 1254 were detected in low concentrations in eggs of western grebes (Aechmophorus occidentalis) from Bear River Migratory Bird Refuge, Utah. DDE was the only contaminant which was both negatively correlated with eggshell thickness and a significant variable in a multiple regression model for predicting eggshell thickness. The eggshell thickness index for western grebe decreased 2.3 percent from pre- to post-DDT-use periods. Incubation stage appeared to have no measurable correlation with eggshell thickness. The small amount of eggshell thinning seen in western grebe eggs at Bear River Migratory Bird Refuge appeared to have no detectable effect on reproduction.  相似文献   
90.
L F Yap  S Low  W Liu  H Loh  T P Teo  J Kwang 《Avian diseases》2001,45(2):410-415
Screening and identification of Salmonella enteritidis in commercial poultry flocks have assumed principal roles in preventing transmission of this pathogen to humans from hen eggs. Serologic diagnosis of S. enteritidis infection in commercial flocks currently relies on laboratory-based tests for detection of antibodies to the lipopolysaccharide, whole flagella, and bacteria. We amplified a sequence from the g,m flagellin of S. enteritidis, followed by cloning, expression, and purification of the protein. The recombinant protein was first characterized by western blot and subsequently evaluated as enzyme-linked immunosorbent assay (ELISA) antigen for detection of S. enteritidis infection. A total number of 49 positive sera and 40 negative sera were tested for ELISA validation. A cutoff value of 0.14 was shown to be sufficient to discriminate the negative and positive sera. Results obtained by testing sera raised against different bacterial strains/serotypes further confirmed that this recombinant flagellin-based ELISA was indeed specific for the detection of S. enteritidis. Both sensitivity and specificity of the developed ELISA test were comparable with a commercially available test, indicating that it is a highly promising and reliable diagnostic tool for S. enteritidis infection.  相似文献   
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