Feedback system design with an uncertain plant

A method is developed to design a fixed-parameter compensator for a linear, time-invariant, SISO (single-input single-output) plant model characterized by significant structured, as well as unstructured, uncertainty. The controller minimizes the H(infinity) norm of the worst-case sensitivity function over the operating band and the resulting feedback system exhibits robust stability and robust performance. It is conjectured that such a robust nonadaptive control design technique can be used on-line in an adaptive control system

Dietary Characteristics of Hyperactive and Control Boys

The purpose of this study was to examine the relationship between dietary habits and behavioral problems in hyperactive boys and to determine how successful parents are in maintaining their children on sugar-free diets. The mothers of 32 hyperactive boys aged 7 to 12 years and 26 matched controls completed 3-day diet records and food frequency interviews. The hyperactive boys were also evaluated in a playroom for impulsivity, compliance, attention, motor activity, memory, and learning. No differences were found in any of the measures of dietary content between the hyperactive and control groups. The only significant differences between those two groups were a lower socioeconomic status and a greater number of parents attempting sugar-restricted diets in the hyperactive group. Boys on sugar-restricted diets had only on significant dietary difference from those not restricted. Correlations between the information obtained in food frequency interviews and in 3-day diet histories were not significant (r=.06 to .33) for the hyperactive group, but the food frequency interviews were significant for the control group (r= .41 to .47). Four behavioral variables showed significant partial correlations with reported sugar intake. Overall, the results demonstrated that the diets of a group of hyperactive boys were similar to those of a control group. There appeared to be little difference between the diets of the families that attempted to restrict sugar and those that did not

The Effects of Stimulant Medication on the Online Story Narrations of Children with ADHD

The current study investigated the inclusion of goal-based story events in the online story narrations of children with ADHD, as compared with their peers, and explored the effect of stimulant medication on the narrations in children with ADHD. Children completed a narration task on two separate occasions. Children with ADHD (n = 17) completed one narration on medication and the other one on placebo. Results indicated that narrations of comparison children (n= 25) were significantly more likely than narrations of children with ADHD to include the story’s positive outcome, completion of the story’s overall goal, and specific attempts linked to the goal. Children with ADHD included a larger total number of clauses in their narrations when on stimulant medication than when on placebo, but medication showed no significant effects for any other variables. Results indicate that stimulant medication may not be effective at reducing goal-based story comprehension deficits in children with ADHD

The Effects of Stimulant Medication on Free Recall of Story Events among Children with ADHD

This study investigated group differences in the recalls of stories by children with attention-deficit/hyperactivity disorder (ADHD) and comparison peers. Further, the study examined whether stimulant medication improved the story recall of children with ADHD relative to a placebo condition. Children were asked to recall both televised and audio taped stories. Free recall protocols were assessed for what information was recalled as a function of story structure features (i.e. status on or off the causal chain and event importance) and were rated for overall coherence. Relative to comparison peers, children with ADHD showed less influence of story structure features on recall, and produced less coherent recall of the audio taped stories. Medication had only limited effects on the story recall of children with ADHD. Specifically, medication did not increase these children’s sensitivity to events central to the stories and had no effect on the coherence of children’s recalls. The implications of the results for guiding future academic interventions are discussed

Alcohol Use and Strenuous Physical Activity in College Students: A Longitudinal Test of 2 Explanatory Models of Health Behavior

Objective: To help clarify the effect of gender on the bidirectional relationship between alcohol use and strenuous physical activity in college students. Participants: Five hundred twenty-four (52% female) college students recruited in August 2008 and 2009 and followed up in April 2009 and April 2011, respectively. Methods: Participants reported their alcohol use and strenuous physical activity on 2 occasions (baseline and follow-up) spaced approximately 1 or 2 years apart. Results: For females, alcohol use quantity at baseline was associated with increased strenuous physical activity at 1- and 2-year follow-ups, and alcohol use frequency at baseline was associated with decreased strenuous physical activity at 2-year follow-up. For males, alcohol use frequency at baseline predicted decreased strenuous physical activity at 1-year follow-up. Conclusions: Gender differences may be explained from an eating disorders perspective such that women use physical activity as a compensatory strategy to combat potential weight gain from calories consumed during alcohol use

Designing a therapeutic hepatitis B vaccine to circumvent immune tolerance

An effective prophylactic hepatitis B virus (HBV) vaccine has long been available but is ineffective for chronic infection. The primary cause of chronic hepatitis B (CHB) and greatest impediment for a therapeutic vaccine is the direct and indirect effects of immune tolerance to HBV antigens. The resulting defective CD4+/CD8+ T cell response, poor cytokine production, insufficient neutralizing anti-body (nAb) and poor response to HBsAg vaccination characterize CHB infection. The objective of this study was to develop virus-like-particles (VLPs) that elicit nAb to prevent viral spread and prime CD4+/CD8+ T cells to eradicate intracellular HBV. Eight neutralizing B cell epitopes from the envelope PreS1 region were consolidated onto a species-variant of the HBV core protein, the woodchuck hepatitis core antigen (WHcAg). PreS1-specific B cell epitopes were chosen because of preferential expression on HBV virions. Because WHcAg and HBcAg are not crossreactive at the B cell level and only partially cross-reactive at the CD4+/CD8+ T cell level, CD4+ T cells specific for WHcAg-unique T cell sites can provide cognate T-B cell help for anti-PreS1 Ab production that is not curtailed by immune tolerance. Immunization of immune tolerant HBV transgenic (Tg) mice with PreS1-WHc VLPs elicited levels of high titer anti-PreS1 nAbs equivalent to wildtype mice. Passive transfer of PreS1 nAbs into human-liver chimeric mice prevented acute infection and cleared serum HBV from mice previously infected with HBV in a model of CHB. At the T cell level, PreS1-WHc VLPs and hybrid WHcAg/HBcAg DNA immunogens elicited HBcAg-specific CD4+ Th and CD8+ CTL responses

Validation of the Wiedemann-Franz Law in solid and molten tungsten above 2000 K through thermal conductivity measurements via steady state temperature differential radiometry

We measure the thermal conductivity of solid and molten tungsten using Steady State Temperature Differential Radiometry. We demonstrate that the thermal conductivity can be well described by application of Wiedemann-Franz Law to electrical resistivity data, thus suggesting the validity of Wiedemann-Franz Law to capture the electronic thermal conductivity of metals in their molten phase. We further support this conclusion using ab initio molecular dynamics simulations with a machine-learned potential. Our results show that at these high temperatures, the vibrational contribution to thermal conductivity is negligible compared to the electronic component

Ensaio regional de variedades de milho na Região Sul - safra 2008/09.

A rede regional de ensaios de variedades de Milho tem por objetivo avaliar o comportamento de variedades comerciais de milho na região sul do Brasil. O resultado dos ensaios é publicado anualmente no Livro das Indicações Técnicas para o Cultivo de Milho e de Sorgo no RS. Esses resultados também servem para determinação do Valor de Cultivo e Uso (VCU), com vistas à extensão da indicação de uso de cultivares comerciais para o RS

Diseño y construcción del modelo a escala de un aerogenerador de eje horizontal para estudios experimentales

En los últimos años, en nuestra región, fundamentalmente Brasil, Chile, Uruguay y Argentina han impulsado fuertemente el desarrollo e instalación de aprovechamientos eólicos, debido a que generan un menor impacto ambiental si se compara con otras fuentes de energía. Con el objeto de optimizar el funcionamiento de los aerogeneradores individualmente o en un parque eólico, es fundamental el estudio de la interacción de la estructura de los mismos y la capa límite atmosférica. Una de las formas de estudiar este comportamiento es mediante ensayos experimentales en túneles de viento utilizando modelos a escala reducida. En este trabajo se describen las etapas de diseño y construcción del modelo a escala de un generador eólico de tres palas de eje horizontal. A partir de los aspectos aerodinámicos vinculados a este tipo de dispositivo, se diseñaron los componentes del aerogenerador y se evaluaron un conjunto de parámetros relacionados al funcionamiento y eficiencia del modelo. El modelo fue construido usando la técnica de impresión 3D de las componentes e incluye un dispositivo para el posicionamiento relativo de las palas con relación a la dirección del viento incidente. Finalmente, el modelo fue montado en el túnel de viento “Jacek Gorecki" de la UNNE y se realizaron ensayos que permitieron una primera evaluación de las características de funcionamiento del aerogenerador a través de la medición de RPM, potencia y torque. Los ensayos se realizaron con viento incidente uniforme considerando dos velocidades distintas; 5,26 m/s y 6,76 m/s. El ángulo que determina la posición de las palas con respecto al viento incidente ha sido modificado para obtener los valores de los parámetros respectivos correspondientes a cada situación.Fil: Milich, Franco G.. Universidad Nacional del NordesteFil: Alvarez y Alvarez, Gisela M. . Universidad Nacional del NordesteFil: Chuaire, Mauricio L.. Universidad Nacional del NordesteFil: Veroli, Cesar G. . Universidad Nacional del NordesteFil: Wittwer, Adrián R.. Universidad Nacional del Nordest

P. falciparum and P. vivax Epitope-Focused VLPs Elicit Sterile Immunity to Blood Stage Infections

In order to design P. falciparum preerythrocytic vaccine candidates, a library of circumsporozoite (CS) T and B cell epitopes displayed on the woodchuck hepatitis virus core antigen (WHcAg) VLP platform was produced. To test the protective efficacy of the WHcAg-CS VLPs, hybrid CS P. berghei/P. falciparum (Pb/Pf) sporozoites were used to challenge immunized mice. VLPs carrying 1 or 2 different CS repeat B cell epitopes and 3 VLPs carrying different CS non-repeat B cell epitopes elicited high levels of anti-insert antibodies (Abs). Whereas, VLPs carrying CS repeat B cell epitopes conferred 98% protection of the liver against a 10,000 Pb/Pf sporozoite challenge, VLPs carrying the CS non-repeat B cell eptiopes were minimally-to-non-protective. One-to-three CS-specific CD4/CD8 T cell sites were also fused to VLPs, which primed CS-specific as well as WHcAg-specific T cells. However, a VLP carrying only the 3 T cell domains failed to protect against a sporozoite challenge, indicating a requirement for anti-CS repeat Abs. A VLP carrying 2 CS repeat B cell epitopes and 3 CS T cell sites in alum adjuvant elicited high titer anti-CS Abs (endpoint dilution titer \u3e1x106) and provided 80–100% protection against blood stage malaria. Using a similar strategy, VLPs were constructed carrying P. vivax CS repeat B cell epitopes (WHc-Pv-78), which elicited high levels of anti-CS Abs and conferred 99% protection of the liver against a 10,000 Pb/Pv sporozoite challenge and elicited sterile immunity to blood stage infection. These results indicate that immunization with epitope-focused VLPs carrying selected B and T cell epitopes from the P.falciparum and P. vivax CS proteins can elicit sterile immunity against blood stage malaria. Hybrid WHcAg-CS VLPs could provide the basis for a bivalent P. falciparum/P. vivax malaria vaccine