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We report reliable, reversible trapping of live magnetotactic bacteria, Magnetospirillum magneticum AMB-1, using a commercial magnetic recording head. The magnetic recording head was modified to generate spatially localized magnetic fields of high magnitude and gradient, and effectively trapped AMB-1, which have a magnetic moment per cell one order of magnitude smaller than cells previously trapped using Amperian fields. We also describe selective trapping of magnetic wild-type AMB-1 with discrimination against a nonmagnetic mutant strain of the same bacteria. Finally, we discuss the prospects of using the built-in spin valve sensor on a recording head for integrated detection of trapped bacteria. Using the chip-based methods we describe, it may be possible to capture, sort, and count magnetic bacteria quickly from samples taken directly from their natural aquatic habitat. More generally, the method may be applicable to the manipulation, spatial control, and integrated detection of magnetically labeled cells and magnetic nanoparticles. [ABSTRACT FROM AUTHOR]

The promotion of polycyclic aromatic hydrocarbon (PAH) degradation was demonstrated in the rhizosphere of Festuca arundinacea with Pseudomonas fluorescens. P. fluorescens 5RL more significantly interacted with salicylate and dextrose in the agar containing tall fescue than agar without plant roots. Although the presence of tall fescue did not promote catabolic enzyme induction in the absence of salicylate, an increase in dioxygenase activity relative to no plant controls implies that this plant may enhance the degradation of PAHs or facilitate the genotypes that are capable of transforming PAH in the rhizosphere. [ABSTRACT FROM AUTHOR]

Sedgley CM, Nagel AC, Hall D, Applegate B.Influence of irrigant needle depth in removing bioluminescent bacteria inoculated into instrumented root canals using real-time imagingin vitro.International Endodontic Journal,38, 97–104, 2005.To test the hypothesis that the mechanical efficacy of irrigation in reducing bacteria in the root canal is dependent on depth of placement of the irrigation needle.The root canals of 30 permanent cuspids were instrumented to apical size 60 using a crown-down technique. A suspension of the bioluminescent reporter strainPseudomonas fluorescens5RL was inoculated into each canal of sterilized teeth. Emission of bioluminescence (photons s−1) from each tooth was quantified on four sequential occasions using luminometry and bioluminescence imaging: (i) background, (ii) after inoculation, (iii) after irrigating the inoculated teeth with 3 mL of a nonantimicrobial irrigant delivered either 1 mm (group 1,n = 15) or 5 mm (group 2,n = 15) from working length (WL) using a 28G safety-ended irrigating needle, (iv) after an additional 3 mL irrigation (total 6 mL). Intragroup and intergroup comparisons were made using Wilcoxon matched pairs and Mann–Whitney tests, respectively.In group 1, there was a mean log10 decrease in bacteria of 0.68 ± 0.26 after 3 mL of irrigant compared with 1.19 ± 0.48 after 6 mL (P < 0.001); in group 2 the mean log10 decrease was 0.58 ± 0.28 after 3 mL of irrigant compared with 0.69 ± 0.35 after 6 mL (P < 0.02) (Wilcoxon matched pairs). Using 3 mL of irrigant, needle depth did not have a significant effect on reduction of intracanal bacteria (P = 0.407), but the effect became significant when 6 mL of irrigant was used (P < 0.002) (Mann–Whitney tests).The mechanical efficacy of 6 mL of irrigant in reducing intracanal bacteria was significantly greater when delivered 1 mm compared with 5 mm from WL. [ABSTRACT FROM AUTHOR]

This study compared vicarious trauma in a random sample of male and female clinicians who treat survivors (n=95) and those who treat offenders (n=252). A national survey was conducted with members of the Association for the Treatment of Sexual Abusers (ATSA) and the American Professional Society on the Abuse of Children (APSAC). These data were used to test the relative contribution of variables theorized to contribute to two vicarious trauma effects (avoidance and intrusions) using the Impact of Event Scale. The sample reported high levels of avoidance and intrusions. Variables associated with vicarious trauma differed based on client population served. Sequential regression analyses were used to examine theoretically derived variables. Implications for practice and further research are discussed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the differences between iEMG activity of the medial head (MH) and lateral head (LH) of the gastrocnemius of normal right legs during partial weight bearing isometric plantarflexion contractions under varying percentages of body weight (BW) and maximal contractions. Fifty-three healthy volunteers ranging in age from 18 to 35, with no history of right lower extremity injury or disease volunteered for this study. Each subject's age, height, weight, and medical history were recorded. A chronaximeter was used to identify the motor points of the MH and LH. After performing a 5-minute warm-up, surface electrodes were placed just distal to the motor point, and subjects were positioned on the sliding board of the Total Gym Therapy System. The percentage of BW used as resistance was determined by the angle of inclination of the slide board. The subjects were then directed to plantarflex to 20 degrees, with 8 second iEMG recordings, with a proprioceptive cue, under four conditions: 30%, isometric (1 trial). Paired t-tests concluded the MH consistently demonstrated a larger percent of total iEMG activity than the LH in the 30, 50, and 70% difference between iEMG activity of the MH and LH during the maximum isometric trial was not statistically significant (p= 0.2958). A repeated measures ANOVA and post-hoc analysis demonstrated the percent of total iEMG differences to be greater at the lighter loads (D30 > D50 > D70; p< 0.0001). These findings strongly suggest separate but complementary functions of the two heads of the gastrocnemius muscle. [ABSTRACT FROM AUTHOR]

In a cross-sectional household sample of 9-through 17-year-old youths from 4 U.S. communities, youths with earlier ages of onset of conduct problems engaged in more conduct problems than youths with later ages of onset when current age and gender were controlled. Specifically, youths with earlier ages of onset were more likely to engage in several types of physical aggression, frequent lying, theft, and vandalism and were less likely to engage in only truancy. There also was an inverse relation between age of onset and level of functional impairment, mental health service use, and meeting diagnostic criteria for conduct disorder, attention-deficit hyperactivity disorder, and oppositional defiant disorder. Within the limits of cross-sectional data, these results support the hypothesis that key aspects of the heterogeneity of conduct problems among youths are related to the age of onset of conduct problems. [ABSTRACT FROM AUTHOR]

Presents several SAS Graph programs for convenient graphical presentations of item and test characteristic curves and related functions from one, two, or three parameter Item Response Theory (IRT) models.