Exposure to inorganic arsenic (iAs) early in life is associated with adverse health effects in infants, children, and adults, and yet the biological mechanisms that underlie these effects are understudied. The objective of this research was to examine the proteomic shifts associated with prenatal iAs exposure using cord blood samples isolated from 50 newborns from Gómez Palacio, Mexico. Levels of iAs in maternal drinking water (DW-iAs) and the sum of iAs and iAs metabolites in maternal urine (U-tAs) were determined. Cord blood samples representing varying iAs exposure levels during the prenatal period (DW-iAs ranging from <1 to 236 μg As/l) were analyzed for altered expression of proteins associated with U-tAs using a high throughput, antibody-based method. A total of 111 proteins were identified that had a significant association between protein level in newborn cord blood and maternal U-tAs. Many of these proteins are regulated by tumor necrosis factor and are enriched in functionality related to immune/inflammatory response and cellular development/proliferation. Interindividual differences in proteomic response were observed in which 30 newborns were "activators," displaying a positive relationship between protein expression and maternal U-tAs. For 20 "repressor" newborns, a negative relationship between protein expression level and maternal U-tAs was observed. The activator/repressor status was significantly associated with maternal U-tAs and head circumference in newborn males. These results may provide a critical groundwork for understanding the diverse health effects associated with prenatal arsenic exposure and highlight interindividual responses to arsenic that likely influence differential susceptibility to adverse health outcomes.
Background: In the Philippines, 86% of incident dialysis patients are started on hemodialysis (HD) and 14% are treated with peritoneal dialysis (PD), representing a decline over a 2-year period. One important factor which affects patients’ choice of dialysis modality is the input of their physicians. Our objective was to identify the factors affecting attitudes and recommendations of Filipino nephrologists regarding HD and PD. Methods: Attendees of the annual national nephrology meeting completed an anonymous self-administered questionnaire. Results: Respondents were heavily involved in clinical dialysis work, and 86.7% had most/all of their patients on HD. Recommendations about dialysis modality were based most strongly on overall cost to patient (4.4 on a scale of 1 [not important] to 5 [most important], residual renal function (RRF) preservation (4.4), patient preference (4.3) availability of dialysis support staff (4.3), and comparative quality of life data (4.3). Least important was physician reimbursement (2.8). Patient-related factors favoring HD were: poor personal hygiene, impaired vision and manual dexterity; while favoring PD were: age <10 years, living far from HD unit, and the availability of trainable family members. When asked which modality they would recommend to an equally eligible patient, 49.2% responded they would not recommend either modality and would allow the patient to choose, while 40.7% would recommend HD and 10.2% would recommend PD. Conclusion: Respondents consider overall cost and RRF preservation as the most important factors in dialysis modality selection, yet only 10.2% would recommend PD as first choice. It is likely that factors other than those addressed in the survey are stronger determinants of the patient’s final choice of modality.
In this paper, the convergence aspects of the Extended Kalman Filter, when used as a deterministic observer for a nonlinear discrete-time systems, are addressed and analyzed. The conditions needed to ensure the boundedness of the error covariances which are related to the observability properties of the nonlinear systems are identified through difference equations. Furthermore, boundedness and stability conditions are provided in a noisy environment systems.
Voltage-mode-control of a phase-shift-modulated fullbridge DC-DC converter, using a digital Proportional-Integral (PI) controller, is described in this paper. For implementing the digital controller, a low cost 16 bit microcontroller, dsPIC30F2010, is used. External hardware requirements are quite minimum, as the microcontroller has an inbuilt PWM module and ADC. Frequency response method is employed here to directly design the digital controller. Alongside, the concern of limit cycle oscillations is addressed, while maintaining converter switching frequency and ADC resolution at comfortably high levels. Performance of the digital feedback controller is checked using a 300 W, 100 V prototype converter.
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