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Effective discipline and contingency management systems in an urban junior high/middle school with an emphasis on developmental needs of young adolescents.
Relative behavior of notch-toughness tests for welded steel
Eleven structural steels in a variety of confitions were tested using the notched slow-bend, Naval Research Laboratory drop-weight and V-notch Charpy tests in order to develop a basis of comparison for these tests
When good bugs go bad: Epidemiology and antimicrobial resistance profiles of Corynebacterium striatum, an emerging multidrug-resistant, opportunistic pathogen
ABSTRACT
Infections with
Corynebacterium striatum
have been described in the literature over the last 2 decades, with the majority being bacteremia, central line infections, and occasionally, endocarditis. In recent years, the frequency of
C. striatum
infections appears to be increasing; a factor likely contributing to this is the increased ease and accuracy of the identification of
Corynebacterium
spp., including
C. striatum
, from clinical cultures. The objective of this study was to retrospectively characterize
C. striatum
isolates recovered from specimens submitted as part of routine patient care at a 1,250-bed, tertiary-care academic medical center. Multiple strain types were recovered, as demonstrated by repetitive-sequence-based PCR. Most of the strains of
C. striatum
characterized were resistant to antimicrobials commonly used to treat Gram-positive organisms, such as penicillin, ceftriaxone, meropenem, clindamycin, and tetracycline. The MIC
50
for ceftaroline was >32 μg/ml. Although there are no interpretive criteria for susceptibility with telavancin, it appeared to have potent
in vitro
efficacy against this species, with MIC
50
and MIC
90
values of 0.064 and 0.125 μg/ml, respectively. Finally, as previously reported in case studies, we demonstrated rapid
in vitro
development of daptomycin resistance in 100% of the isolates tested (
n
= 50), indicating that caution should be exhibited when using daptomycin for the treatment of
C. striatum
infections.
C. striatum
is an emerging, multidrug-resistant pathogen that can be associated with a variety of infection types.
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Critical-layer structures and mechanisms in elastoinertial turbulence
Simulations of elastoinertial turbulence (EIT) of a polymer solution at low
Reynolds number are shown to display localized polymer stretch fluctuations.
These are very similar to structures arising from linear stability
(Tollmien-Schlichting (TS) modes) and resolvent analyses: i.e., critical-layer
structures localized where the mean fluid velocity equals the wavespeed.
Computation of self-sustained nonlinear TS waves reveals that the critical
layer exhibits stagnation points that generate sheets of large polymer stretch.
These kinematics may be the genesis of similar structures in EIT.Comment: 5 pages, 4 figures; Accepted in Physical Review Letter
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