4,013 research outputs found
Adaptive Function Segmentation Methodology for Resources Optimization of Hardware-Based Function Evaluators
This thesis presents a new adaptive function segmentation methodology (AFSM), for the evaluation of mathematical functions through piecewise polynomial approximation (PPA) methods. This methodology is planned to be employed for the development of an efficient hardware-based channel emulator in future development steps of the current project. In contrast to state-of-art segmentation methodologies, which applicability is limited because these are highly dependent on the function shape and require significant intervention from the user to setup appropriately the algorithm, the proposed segmentation methodology is flexible and applicable to any continuous function within an evaluation interval. Through the analysis of the first and second order derivatives, the methodology becomes aware of the function shape and adapts the algorithm behavior accordingly. The proposed segmentation methodology aims towards hardware architectures of limited resources that resort to fixed-point numeric representation where hardware designer should make a compromise between resources consumption and output accuracy. An optimization algorithm is implemented to assist the user in searching the best segmentation parameters that maximize the outcome of the design trade-offs for a given signal-to-quantization-noise ratio requirement. When compared to state-of-the-art segmentation methodologies, the proposed AFSM delivers better performance of approximation for the hardware-based evaluation of transcendental functions given that fewer segments and consequently fewer hardware resources are required.Consejo Nacional de Ciencia y TecnologĂ
New method for the deposition of nickel oxide in porous scaffolds for electrodes in solid oxide fuel cells and electrolyzers
A simple chemical bath deposition is used to coat a complex porous ceramic scaffold with a conformal nickel layer. The resulting composite is used as a Solid Oxide Fuel Cell electrode and its electrochemical response is measured in humidified hydrogen. X-Ray tomography is used to determine microstructural parameters of the uncoated and Ni-coated porous structure, among other, the surface area to total volume, the radial pore size and size of the necks between pores
The Impact of Faculty Feedback on Student Perceptions of Faculty-Student Relationships
This qualitive study examined four communication sciences and disorders (CSD) graduate students’ experiences with feedback from CSD faculty members to understand how it affected their relationships with faculty. Review of the literature revealed the importance and impact of feedback; however, it offered little research examining feedback within the field of CSD. Graduate CSD students who completed their undergraduate degrees in CSD were interviewed to reflect on feedback experiences they received from faculty during their undergraduate and graduate education. The students were also presented with two mock papers with differing feedback styles and were asked their reactions to the feedback. It was discovered that feedback received directly contributed to faculty’s overall perceived approachability, with more imbalanced critical feedback increasing the perception of unapproachability towards faculty members. Additionally, the feedback modality, language used, and balance of positive and negative comments strongly influenced participant’s perception of the feedback being given as an inherently pleasant or unpleasant
Peruvian Parents Perceptions of Children's Obesity
Although parents are critical to childhood obesity prevention, little is known about Peruvian parents' perceptions regarding childhood obesity, a country undergoing an emerging obesity epidemic. The study assessed Peruvian parents' perceptions regarding their children's obesity risks and behaviors. The specific objectives were to: (a) assess the knowledge, attitudes, and behaviors of parents regarding nutrition and physical activity of their preschool-aged children, and (b) assess parents’ ability to recognize overweight status in their children. Methods: The cross-sectional study surveyed 202 parents of preschool children (Mean age= 49.4 months, SD = 8.5) in the peri-urban slum communities of Lima, Peru utilizing a modified version of the Behavior and Attitudes Questionnaire for Healthy Habits (BAQ-HH) questionnaire. Children's body mass index (BMI) was compared with parental descriptions of the child's weight. Results: Nearly half (41.3%) of children had exceeded healthy weight (defined as BMI- for-age Z- score >-2 and £1). Parents demonstrated high knowledge, positive behaviors, and concerned attitudes. Parental knowledge and attitude scores predicted parental behavior scores (p=0.004). More than half (56.6%) accurately perceived their child's weight. However, 90.4% of parents of overweight/obese children underestimated their weight. Conclusions: Understanding Peruvian parents' perceptions of their children's obesity risk is essential to planning comprehensive interventions
Gasotransmitters, poisons, and antimicrobials: it's a gas, gas, gas!
We review recent examples of the burgeoning literature on three gases that have major impacts in biology and microbiology. NO, CO and H2S are now co-classified as endogenous gasotransmitters with profound effects on mammalian physiology and, potentially, major implications in therapeutic applications. All are well known to be toxic yet, at tiny concentrations in human and cell biology, play key signalling and regulatory functions. All may also be endogenously generated in microbes. NO and H2S share the property of being biochemically detoxified, yet are beneficial in resisting the bactericidal properties of antibiotics. The mechanism underlying this protection is currently under debate. CO, in contrast, is not readily removed; mounting evidence shows that CO, and especially organic donor compounds that release the gas in biological environments, are themselves effective, novel antimicrobial agents
CO-releasing Metal Carbonyl Compounds as Antimicrobial Agents in the Post-antibiotic Era
The possibility of a “post-antibiotic era” in the 21st century, in which common infections may kill, has prompted research into radically new antimicrobials. CO-releasing molecules (CORMs), mostly metal carbonyl compounds, originally developed for therapeutic CO delivery in animals, are potent antimicrobial agents. Certain CORMs inhibit growth and respiration, reduce viability, and release CO to intracellular hemes, as predicted, but their actions are more complex, as revealed by transcriptomic datasets and modeling. Progress is hindered by difficulties in detecting CO release intracellularly, limited understanding of the biological chemistry of CO reactions with non-heme targets, and the cytotoxicity of some CORMs to mammalian cells
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