This paper discusses the design and use of low-temperature (850°C to 950°C) cofired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low-voltage to high-voltage (> 100-V) with significant volumetric constraints. Measured performance and modeling results for multiple designs show that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling, and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrate LTCC transformer designs capable of greater than 2-kV output. Finally, the paper investigates the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this paper applies to designs requiring lower voltage.
Summary of the results in the context of EDCAT 5 project aims: 1. By comparing appropriate biomarkers in fish sampled from STW-impacted sites and control sites during the pre-remediation period, to determine whether there was evidence for any effects that might be attributed to the presence of estrogenic (or androgenic, or anti-androgenic/-estrogenic) endocrine disrupting chemicals in the former. This aim was addressed by measuring concentrations of the estrogen-dependent yolk protein precursor vitellogenin, and the androgen-dependent nest glue spiggin in male and female sticklebacks. In addition histological examination of the gonadal structure of fish captured at the impacted and non-impacted sites was employed to seek evidence of overt alterations in reproductive physiology of the fish. For a subset of matched samples from the two rivers, the relative induction of hepatic choriogenin mRNA, a biomarker of estrogen exposure, was measured. Conclusions: Chemistry data provided by EDCAT3&4 showed that estrogenicity of the effluent was low prior to remediation and lower still following installation of the GAC plant. No evidence of overt estrogenic effects was detected in male sticklebacks in the Ray, VTG and ChG levels were similar in males from both rivers. Nor was there any evidence of alterations in spiggin concentrations in the kidneys of males from the Ray compared to the Ock. However, VTG concentrations in female sticklebacks from the Ray were increased following the STW upgrade as were hepatic ChG transcript levels, and kidney spiggin concentrations. No changes in these elements of the reproductive system were observed in females from the Ock across the same time periods. Chemical analysis of the effluent indicated that prior to installation of the GAC plant substantial concentrations of anti-androgenic chemicals were present, together with a wide range of other organics. Concentrations of these were much reduced following the plant upgrade. It is reasonable to suppose that the changes observed in the female reproductive endocrine system following the upgrade were related to the removal of some or all of this complex mixture of chemicals. The absence of effects in males may be related to the balance between exogenous and endogenous signals, or to the specificity of effects exerted by the chemicals present. No intersex fish were detected from either river. A significant bias in favour of females was detected in the stickleback populations in both rivers suggesting a factor associated with life-history of the fish, rather than contaminant burden, was responsible. 2. By comparing appropriate biomarkers in fish sampled from STW-impacted sites and control sites during the pre-remediation period, to determine whether there was evidence for any effects that might be attributed to the presence of “conventionally” toxic chemicals. This was addressed by measurement of the activity of a key Phase I transforming enzyme in the liver of fish, either using direct enzymatic assay (EROD) or by quantifying the levels of expression of the corresponding gene (CYP1A). Conclusions: EROD activity was significantly greater in fish from the Ray than the Ock in two samples collected prior to the installation of the GAC plant (2006, 2007) and this likely reflects the differential contaminant loading in the two rivers. A single sample following the commissioning of the GAC plant (2008) indicated that EROD activity had increased among fish from the Ock while that in fish from the Ray remained unchanged. While a delayed recovery of this biomarker in fish from the Ray may be expected depending on the route of exposure (direct via water or indirect via contaminated food) the reasons for elevated EROD activity in fish from the Ock/Childrey Brook are not immediately evident. Provision of a full data set for Cyp1A expression awaits the repeat of the assay. When this is complete the factors underlying the EROD findings may become clear. 3. To determine whether the adaptive capacity and energetic status of fish varied between the STW-impacted and non-impacted sites. This was addressed by measurement of indicators of stress (whole-body corticosteroid levels), metabolic status (whole-body glucose levels) and anabolic activity (RNA:DNA ratios). Conclusions: The data provide no evidence that the stress response of fish captured in the Ray prior to installation of the GAC plant was modified by exposure to the effluent. However, large variations in whole-body corticosteroid and glucose concentrations in fish from both rivers, with clear trends over time, were closely linked to perturbations in the river flow regime. Whether there was interaction between environmental and chemical factors in determining corticosteroid and glucose status is difficult to discern but it seems likely that variation in these indicators of the stress axis was driven primarily by environmental factors. The RNA:DNA ratios were closely linked with seasonal change in temperature and closely matched observed patterns of weight and length gain in stickleback populations in the two rivers. The longer growth period enjoyed by fish in the Ray was clearly evident. For both rivers, mean anabolic activity was greater during 2008 than 2007 and it seems likely that this is related to adverse effects associated with the periods of extreme flow change observed on both rivers in 2007. 4. To assess whether there were differences in population size and structure between STW-impacted and non-impacted sites. This was addressed by comparison of key somatic measures, in particular frequency distributions for fork length. Conclusions: Because of the extreme patchiness of the distribution of stickleback populations in both rivers accurate abundance estimates were not obtained. However, the catch per unit effort across the life of the project was similar for both rivers. While population size, and age structure (both rivers hosted annual populations), appeared to be similar fish in the Ray were overall larger than those from the Ock, and spawned earlier. The differences in growth and timing of spawning between the rivers were likely to have been associated with the Rodbourne STW effluent. Downstream of the discharge on the Ray water temperatures were consistently 2 – 3oC above those of the Ock. This temperature difference, in combination with the introduction of additional nutrients into the river which is likely to have affected the availaibility of food, probably accounts for the different growth profile among the sticklebacks in the two rivers. However, over and above this difference, there was a significant increase in size of sticklebacks in the Ray between the matched pre- and post-remediation periods in the Ray while no change in size of the fish in the Ock occurred during the same period. Similarly, the RNA:DNA ratio was higher in fish from the Ock during 2007 but greater in fish from the Ray during 2008. Taken together, these observations suggest that there was an improvement in the status of the fish in the Ray following the commissioning of the GAC plant, while the population in the Ock remained relatively stable. It is reasonable to suppose that this may be linked to the reduction of the chemical load entering the Ray at Rodbourne following the installation of the GAC plant. The Ray is “cleaner” now than was the case prior to remediation but remains nutrient rich and several degrees warmer than the Ock, this combination of factors providing fish in the Ray with greater scope for growth relative to populations in the Ock.
Reconnecting a child with an absent parent is a complex process. This article describes variables influencing the reconnection and proposes a seven‐stage model for supporting successful reconnections. Case examples illustrate the discussion. Ethical dilemmas for practitioners and courts involved in reconnections are outlined. Guidelines for working with reconnections and directions for future work are proposed. Experience with the model underscores the importance of maintaining a child‐centered focus and timeline, understanding safety and risk issues and implementing an appropriate safety plan, the critical role of assessment and support services, and the value of consultation and teamwork.
Reconnecting a child with an absent parent is a complex process. This article describes variables influencing the reconnection and proposes a seven-stage model for supporting successful reconnections. Case examples illustrate the discussion. Ethical dilemmas for practitioners and courts involved in reconnections are outlined. Guidelines for working with reconnections and directions for future work are proposed. Experience with the model underscores the importance of maintaining a child-centered focus and timeline, understanding safety and risk issues and implementing an appropriate safety plan, the critical role of assessment and support services, and the value of consultation and teamwork.
The term multiplex PCR refers to simultaneous amplification of more than one target in a single PCR. This method has some advantages but presents the possibility of competition between multiple targets for a finite number of reagents, which may invalidate the assay. The Roche Cobas AMPLICOR multiplex PCR for Chlamydia trachomatis and Neisseria gonorrhoeae, a U.S. Food and Drug Administration-approved assay, can detect both C. trachomatis and N. gonorrhoeae from a single specimen. PCR amplification of C. trachomatis and N. gonorrhoeae proceeds in one tube with a shared enzyme and shared nucleotides but independent biotinylated primers. An optional internal control (IC) permits detection of amplification inhibition. The IC DNA has primer binding sequences identical to those of the C. trachomatis target. Detection is accomplished by using oligonucleotide probes that are unique for C. trachomatis, N. gonorrhoeae, and IC, respectively, with colorimetric quantification by spectophotometer. A negative assay result is valid if the IC optical density (OD) is ≥0.2, indicating successful amplification (Method Manual, Cobas Amplicor, Roche Diagnostics, 12/1999, Revision 3.0). We performed 580 multiplex PCRs on endocervical and urethral swab specimens, and 58 assays yielded positive results for C. trachomatis alone (OD ≥ 2.0), 13 assays yielded positive results for N. gonorrhoeae alone (OD ≥ 3.5), and 4 assays yielded positive results for both. Of the 58 assays positive for C. trachomatis, 13 (22.4%) had IC OD values that were <0.2 (mean OD, 0.059). The results of these 13 assays were correctly interpreted as C. trachomatis positive (mean C. trachomatis OD, 3.187). Because of the failure of the IC to amplify, the N. gonorrhoeae OD values for these 13 were invalid. The limiting reagent could be the primer, shared by C. trachomatis and IC. In the absence of IC amplification, it was not clear that there were a sufficient number of reagents, aside from the primer, to amplify N. gonorrhoeae. Of these 13 assays, 11 had OD values interpreted as negative for N. gonorrhoeae (mean N. gonorrhoeae OD, 0.047). Five of these specimens from the 11 assays were cultured and yielded negative results. Two additional specimens that turned out to be N. gonorrhoeae culture positive had equivocal N. gonorrhoeae OD values of 2.013 and 3.492, respectively, resolvable as positive by duplicate repeat testing. A Roche Molecular Systems study suggested that competitive inhibition occurs when the relative concentration of one target is extremely high and that the competition is for reagents other than the primer. This Roche paper discusses the optional use of the IC for increased sensitivity as well as retesting of existing specimens to eliminate nonspecific, labile polymerase inhibition, which we saw in five specimens not discussed here (1). However, we had a very high rate of competitive inhibition not correctable by repetition. Experimental dilution of the specimens did result in IC amplification, but also, in one case, converted a positive C. trachomatis assay result to negative. The Molecular Pathology Checklist of the College of American Pathologists states that “the laboratory should be able to distinguish a true negative result from a false negative result due to PCR failure.” ICs accomplish this. The competitive inhibition described could be resolved by repeat amplification with only the N. gonorrhoeae primer. For the two equivocal specimens, positive for C. trachomatis, the initial OD value cutoff for N. gonorrhoeae positivity could be lower than the stated 3.5; perhaps 2.0 could be used as the cutoff OD value for duplicate repeat testing of specimens that produce equivocal results. Competitive inhibition is not fully addressed in the Method Manual. Undetected false negatives, due to failure to include the so-called optional IC, are misleading.