Erratum: First Measurements of Fuel-Ablator Interface Instability Growth in Inertial Confinement Fusion Implosions on the National Ignition Facility [Phys. Rev. Lett. 117, 075002 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.117.075002.

First Measurements of Fuel-Ablator Interface Instability Growth in Inertial Confinement Fusion Implosions on the National Ignition Facility.

Direct measurements of hydrodynamic instability growth at the fuel-ablator interface in inertial confinement fusion (ICF) implosions are reported for the first time. These experiments investigate one of the degradation mechanisms behind the lower-than-expected performance of early ICF implosions on the National Ignition Facility. Face-on x-ray radiography is used to measure instability growth occurring between the deuterium-tritium fuel and the plastic ablator from well-characterized perturbations. This growth starts in two ways through separate experiments-either from a preimposed interface modulation or from ablation front feedthrough. These experiments are consistent with analytic modeling and radiation-hydrodynamic simulations, which say that a moderately unstable Atwood number and convergence effects are causing in-flight perturbation growth at the interface. The analysis suggests that feedthrough from outersurface perturbations dominates the interface perturbation growth at mode 60.

Changes in shear wave speed pre- and post-induction of labor: a feasibility study.

OBJECTIVE: To explore the feasibility of using shear wave speed (SWS) estimates to detect differences in cervical softening pre- and post-ripening in women undergoing induction of labor. METHODS: Subjects at 37-41 weeks' gestation undergoing cervical ripening before induction of labor were recruited (n = 20). Examinations, performed prior to administration of misoprostol and 4 h later included Bishop score, transvaginal ultrasound measurement of cervical length, and 10 replicate SWS measurements using an ultrasound system equipped with a prototype transducer (128 element, 3 mm diameter, 14 mm aperture) attached to the clinician's hand. Subjects were divided into two groups, 'not-in-labor' and 'marked-progression', based on cervical evaluation at the second examination. Measurements were compared via individual paired hypotheses tests and using a linear mixed model, with the latter also used to compare groups. Spearman's rank correlation coefficient was used to compare SWS with Bishop score. The linear mixed model can take into account clustered data and accommodate multiple predictors simultaneously. RESULTS: The Wilcoxon signed-rank paired test established a significant difference in pre- and post-ripening SWS, with mean SWS estimates of 2.53 ± 0.75 and 1.54 ± 0.31 m/s, respectively (P < 0.001) in the not-in-labor group (decrease in stiffness) and 1.58 ± 0.33 and 2.35 ± 0.65 m/s for the marked-progression group (increase in stiffness). The linear mixed model corroborated significant differences in pre- and post-ripening measurements in individual subjects (P < 0.001) as well as between groups (P < 0.0001). SWS estimates were significantly correlated with digitally-assessed cervical softness and marginally correlated with Bishop score as assessed by Spearman's rank correlation coefficient. CONCLUSIONS: In-vivo SWS estimates detected stiffness differences before and after misoprostol-induced softening in term pregnancies. This ultrasonic shear elasticity imaging technique shows promise for assessing cervical softness.

Estimation of shear wave speed in the human uterine cervix.

OBJECTIVES: To explore spatial variability within the cervix and the sensitivity of shear wave speed (SWS) to assess softness/stiffness differences in ripened (softened) vs unripened tissue. METHODS: We obtained SWS estimates from hysterectomy specimens (n = 22), a subset of which were ripened (n = 13). Multiple measurements were made longitudinally along the cervical canal on both the anterior and posterior sides of the cervix. Statistical tests of differences in the proximal vs distal, anterior vs posterior and ripened vs unripened cervix were performed with individual two-sample t-tests and a linear mixed model. RESULTS: Estimates of SWS increase monotonically from distal to proximal longitudinally along the cervix, they vary in the anterior compared to the posterior cervix and they are significantly different in ripened vs unripened cervical tissue. Specifically, the mid position SWS estimates for the unripened group were 3.45 ± 0.95 m/s (anterior; mean ± SD) and 3.56 ± 0.92 m/s (posterior), and 2.11 ± 0.45 m/s (anterior) and 2.68 ± 0.57 m/s (posterior) for the ripened group (P < 0.001). CONCLUSIONS: We propose that SWS estimation may be a valuable research and, ultimately, diagnostic tool for objective quantification of cervical stiffness/softness.

Central venous catheter-related bacteremia due to Tsukamurella species in the immunocompromised host: a case series and review of the literature.

We report 6 cases of bacteremia due to Tsukamurella species, all of which were in immunosuppressed patients with indwelling central venous catheters (CVCs). Fewer than 20 cases of serious illness due to these gram-positive bacilli have been reported in the medical literature; these cases have mostly been ascribed to the species Tsukamurella paurometabola. Tsukamurella species are frequently misidentified as Rhodococcus or Corynebacterium species. We used high-performance liquid chromatography to identify these organisms to the genus level and 16S ribosomal RNA gene sequencing and DNA-DNA dot blots for species identification. Three of our isolates were identified as Tsukamurella pulmonis, 1 was identified as Tsukamurella tyrosinosolvans, and 1 was identified as a unique species. One isolate was not maintained long enough for species identification. All patients were successfully treated with antimicrobial therapy and CVC removal. Infection with this organism should be considered in the immunosuppressed patient with an indwelling CVC and gram-positive bacilli in the blood.

Diversity within reference strains of Corynebacterium matruchotii includes Corynebacterium durum and a novel organism.

Corynebacterium matruchotii has been the subject of numerous dental pathogenesis studies. The purpose of the present study was to resolve concerns about diversity within the reference strains of C. matruchotii through analysis of seven strains procured from the American Type Culture Collection (ATCC). Analysis of whole-cell fatty acid profiles with the library generation software of Microbial ID Inc. revealed that three types of organisms have been deposited in the ATCC as C. matruchotii. These three groups of organisms were also distinguishable by DNA-DNA dot blot hybridization, by sequences of two hypervariable regions of the 16S rRNA gene, and by the pyrrolidonyl arylamidase test. These studies indicate that two C. matruchotii reference strains, ATCC 33449 and ATCC 33822, are members of the recently proposed species, Corynebacterium durum. The colonial morphology and biochemical reactions of the C. durum strains are more diverse than originally reported. Strain ATCC 43833 is unique and represents a novel species. In addition to the type strain, ATCC 14266, true members of the species C. matruchotii include ATCC strains 14265, 33806, and 43832 plus two reference strains, L2 and Richardson 13, which comprise the vast majority of strains used in dental pathogenesis research with this species.

Application of 16S rRNA gene sequencing to identify Bordetella hinzii as the causative agent of fatal septicemia.

We report on the first case of fatal septicemia caused by Bordetella hinzii. The causative organism exhibited a biochemical profile identical to that of Bordetella avium with three commercial identification systems (API 20E, API 20 NE, and Vitek GNI+ card). However, its cellular fatty acid profile was not typical for either B. avium or previously reported strains of B. hinzii. Presumptive identification of the patient's isolate was accomplished by traditional biochemical testing, and definitive identification was achieved by 16S rRNA gene sequence analysis. Phenotypic features useful in distinguishing B. hinzii from B. avium were production of alkali from malonate and resistance to several antimicrobial agents.

Bacteremia caused by a novel Bordetella species, "B. hinzii".

Bordetella spp. cause respiratory tract diseases in warm-blooded animals. Only Bordetella bronchiseptica has been reported to cause bacteremia in humans, and this rare infection usually occurs with pneumonia in immunocompromised patients. We describe "Bordetella hinzii" bacteremia in an AIDS patient without a respiratory illness. Combining biochemical phenotyping with fatty acid analysis permitted preliminary identification of this previously undescribed pathogen; identity was confirmed by DNA-DNA hybridization. This report extends the spectrum of human infections caused by the bordetellae.

Laboratory aspects of "Mycobacterium genavense," a proposed species isolated from AIDS patients.

"Mycobacterium genavense" is a proposed new species recently reported to cause disseminated infections in 18 patients with AIDS in Europe. We have recovered "M. genavense" as slowly growing fastidious mycobacteria in blood cultures of seven patients with AIDS. In the original studies of "M. genavense," the fastidious organism grew only in BACTEC 13A vials. The Seattle, Washington, isolates of "M. genavense" also failed to grow when subcultured from 13A vials to routine solid media, but dysgonic colonies were produced on Middlebrook 7H11 agar supplemented with mycobactin J. The mycolic acid pattern of patients' isolates closely resembled that of the type strain of Mycobacterium simiae when analyzed by one- and two-dimensional thin-layer chromatography and by high-performance liquid chromatography. Whole-cell fatty acid analyses by gas-liquid chromatography distinguished the isolates from M. simiae but misidentified them as Mycobacterium fortuitum. Sequence determinations of the hypervariable regions of the 16S rRNA gene indicate that these organisms belong to the recently proposed new species "M. genavense." Growth from Middlebrook 7H11 agar supplemented with mycobactin J consistently yielded positive tests for catalase (semiquantitative and at 68 degrees C), pyrazinamidase, and urease which enable mycobacteriology laboratories to presumptively identify "M. genavense" without nucleic acid analyses. The failure of "M. genavense" to grow on conventional mycobacterial solid media suggests that mycobacterial blood cultures should include a broth medium incubated for at least 8 weeks.

Evaluation of four mycobacterial blood culture media: BACTEC 13A, Isolator/BACTEC 12B, Isolator/Middlebrook agar, and a biphasic medium.

Four commercially available mycobacterial blood culture systems were compared for sensitivity and time to detection of growth. A 5-ml volume of SPS-anticoagulated blood was cultured in a BACTEC 13A vial and a modified M7H11/BHI biphasic medium. In addition, two aliquots of Isolator concentrates, each derived from 5 ml of blood, were inoculated into a BACTEC 12B vial and onto a pair of Middlebrook 7H11 agar plates (M7H11). Mycobacteria were recovered from 32 of 180 cultured specimens (17.8%). Growth was detected in 30 (93.7%) of the 13A vials, 27 (84.4%) of the M7H11 agar plates, 26 (81.2%) of the 12B vials, and 14 (43.8%) of the biphasic bottles. The mean times to growth detection in the 13A vial (14.2 days) and the 12B vial (13.7 days) were shorter than in either the M7H11 plates (20.8 days) or the biphasic medium (24.1 days). When the Isolator/12B vial-and-M7H11 plates were evaluated as a single system, 29 cultures (90.6%) had a mean time to growth detection of 13.5 days. Colony-forming units per ml were inversely associated with time to growth detection. Delay in transport (greater than 24 h) appeared to reduce viability. The direct inoculation feature makes the 13A vial very suitable for mycobacterial blood cultures.