Impulse responses in a hall were calculated by the finite-difference time-domain (FDTD) method, and typical room acoustic parameters were obtained from the responses. The calculated parameters were compared with those actually measured in the hall. In the FDTD calculation, the impedance boundary condition was modeled by an equivalent mechanical system comprising masses, springs, and dampers. To calculate the impulse responses, the normal acoustic impedance of the interior finishing materials of the various surfaces in the hall were measured by applying the impedance-tube method, and the model of the room boundary condition was determined for the respective parts. A comparison between the calculated and measured values showed that the values of reverberation time RT, definition D 50 , clarity C 80 , and center time T s were in good agreement in the middle-frequency bands. However, in low-frequency bands, large discrepancies were observed because of the difficulties in determining and modeling the boundary conditions.

ABSTRACT. We examined the susceptibility in vitro of 99 isolates of Mycoplasma (M. bovirhinis, M. bovis, M. alkalescens and M. bovoculi) and one of Acholeplasma laidlawii collected in 2008 and 2009 from Japanese homebred cattle and cows imported from Australia to 13 antimicrobial agents. Mycoplasma species isolated from homebred cattle were susceptible to spectinomycin and fluoroquinolones but resistant to macrolides, tetracyclines, thiamphenicol and flumequine. Kanamycin, lincomycin and chloramphenicol maintained intermediate effectiveness against these species. The isolates from the imported cows maintained sufficient susceptibility to all antimicrobials examined except for erythromycin and thiamphenicol. These results showed that four species of Mycoplasma isolated from Japanese homebred cattle had obviously higher drug resistance compared with previous reports, even within this decade.KEY WORDS: bovine respiratory diseases, drug resistance, Mycoplasma spp.J. Vet. Med. Sci. 72(12): 1661-1663, 2010 Bovine respiratory disease complex (BRDC) caused by several combinations of viral and bacterial infections together with stress is a significant problem that has considerable economic impact on the cattle industry [4,12]. Mycoplasma is a causative agent of BRDC [2,6,7,10,12]. Because vaccination of cattle to prevent Mycoplasma infection has not yet been approved in Japan, other approaches are needed, such as preventing bacterial invasion of farms through hygiene management, preventing respiratory symptoms through nutritional management and antibiotic treatment of cattle with abnormal respiratory manifestations. Although the antimicrobial susceptibility of Mycoplasma species has changed [6,7,10], there has been no report of examination of the susceptibility in Japan since isolates were collected from 1996-1997 [6]. Therefore, this study examined the antimicrobial susceptibility of Mycoplasma strains recently isolated from cattle in Japan.We analyzed 99 isolates of Mycoplasma (M. bovirhinis, M. bovis, M. alkalescens and M. bovoculi) and one of Acholeplasma laidlawii collected in 2008 and 2009 from Japanese homebred cattle that were 15 days to 11 months old at 33 farms in Kyusyu and healthy cows imported from Australia that were 14 to 15 months old. At the time of sampling, the Australian cattle were isolated from other cows because of quarantine restrictions at the destination farm.We examined the minimum inhibitory concentrations (MICs) of 13 antimicrobial agents (kanamycin, spectinomycin, erythromycin, tylosin, tilmicosin, lincomycin, oxytetracycline, chlortetracycline, chloramphenicol, thiamphenicol, flumequine, enrofloxacin and danofloxacin) required to completely suppress the growth of the four species of Mycoplasma and A. laidlawii. The MICs were determined using agar dilution according to the Clinical and Laboratory Standards Institute (CLSI) guidelines [3] and a previous report [5]. Mycoplasma species and A. laidlawii were grown and diluted 1:100 in M broth [9]. Bacterial suspensions (about 10 6 colony formi...

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SCE-129 [3-(4-carbamoyl-1-pyridiniomethyl)-7,8-(D-a-sulfophenylacetamido)-ceph-3-em-4-carboxylate monosodium salt], a new semisynthetic cephalosporin, shows potent in vitro antibacterial activities against Pseudomonas aeruginosa and some gram-positive bacteria, whereas it shows lower activity against many gram-negative rods. Against clinical isolates of P. aeruginosa this cephalosporin exhibited higher activity than did carbenicillin, and against the strains of Staphylococcus aureus, SCE-129 had similar activity to carbenicillin. Variations in pH, addition of horse serum, and type of growth medium had no significant effects on the activity of the cephalosporin; however, the inoculum size had some effect on the activity. SCE-129 is an effective bactericidal agent against P. aeruginosa and S. aureus. The protective effects of SCE-129 in mice infected with P. aeruginosa and S. aureus were more potent than those of carbenicillin. The protective effects of SCE-129 on Pseudomonas infection in mice varied according to the dosage schedule and the challenge dose. In a multiple dose schedule, a smaller amount of SCE-129 was necessary than that in a single dose schedule. The effects of SCE-129 after subcutaneous or intraperitoneal administration were more potent than were those by intravenous administration. No protective effect was observed by oral administration.

Fifty‐seven Shiga toxin‐producing Escherichia coli (STEC) strains isolated from pigs with edema disease (ED) from 1997 to 2001 in Japan were examined for antimicrobial susceptibilities. The susceptibilities were compared with those of E. coli ATCC 23546 isolated from pig with ED in the 1950's. Consequently, the isolated STECs showed high susceptibility to peptides and bicozamycin in a way similar to the reference strain. On the other hand, the STECs showed low susceptibility to beta‐lactams, tetracyclines, novobiocin, fosfomycin, trimethoprim, and old quinolones. It became clear that the susceptibilities of the isolated STECs had diminished in regard to antimicrobials.