The effect of an early childhood obesity intervention on father's obesity risk behaviors: the Melbourne InFANT program

Background
To investigate the effect of an early childhood obesity prevention intervention, incorporating a parent modelling component, on fathers’ obesity risk-related behaviours.

Methods
Cluster randomized-controlled trial in the setting of pre-existing first-time parents groups organised by Maternal and Child Health Nurses in Victoria, Australia. Participants were 460 first-time fathers mean age = 34.2 (s.d.4.90) years. Dietary pattern scores of fathers were derived using principal component analysis, total physical activity and total television viewing time were assessed at baseline (infant aged three to four months) and after 15 months.

Results
No significant beneficial intervention effect was observed on fathers’ dietary pattern scores, total physical activity or total television viewing time.

Conclusion
Despite a strong focus on parent modelling (targeting parents own diet, physical activity and television viewing behaviours), and beneficial impact on mothers’ obesity risk behaviours, this intervention, with mothers as the point of contact, had no effect on fathers’ obesity risk-related behaviours. Based on the established links between children’s obesity risk-related behaviors and that of their fathers, a need exists for research testing the effectiveness of interventions with a stronger engagement of fathers.

Voltage stability analysis with optimum size and location based synchronous machine DG

Power loss of a distribution system can be reduced significantly by using optimum size and location of distributed generation (DG). Proper allocation of DG with appropriate size maximizes overall system efficiency. Moreover it improves the reliability and voltage profile of the distribution system. In this paper, IEEE 123 node test feeder has been considered to determine the optimum size and location of a synchronous machine based DG for loss reduction of the system. This paper also investigates the steady-state and dynamic voltage profile of that three phase unbalance distribution network in presence of DG with optimum size. This analysis shows that optimum size of DG at proper location minimizes the power loss as well as improves the dynamic voltage profile of the distribution system.

Vector control of a position sensorless SPMSM drive with RNN based stator flux estimator

A position sensorless Surface Permanent Magnet Synchronous Motor (SPMSM) drive based on single layer Recurrent Neural Network (RNN) is presented in this paper. The motor equations are written in rotor fixed d-q reference frame. A PID controller is used to process the speed error to generate the reference torque current keeping the magnetizing current fixed. The RNN estimator is used to estimate flux components along the stator fixed stationary axes. The flux angle and the reference current phasor angle are used in vector rotator to generate the reference phase currents. Hysteresis current controller block controls the switching of the three phase inverter to apply voltage to the motor stator. Simulation studies on different operating conditions indicate the acceptability of the drive system. The proposed estimator can be used to accurately measure the motor fluxes and rotor angle over a wide speed range. The proposed control scheme is robust under load torque disturbances and motor parameter variations. It is also simple and low cost to implememnt in a practical environment

The impact of IT intervention programs for girls

The goal of our study is to investigate the longitudinal effects of one intervention program for schoolgirls in the Information Technology (IT) field. This bi-annual event has been conducted regularly since 2006 with the aim of confronting a decline in the interest among girls to study IT and promoting study and work opportunities in the field. Each event has been evaluated with pre- and post-event surveys. Longitudinally, both students and teachers have also been surveyed three to four years after the event in which they participated. Results from the 2006 cohort surveyed in 2009-2010 are reported on in this paper. The main conclusion is that, unfortunately, any increase in the uptake of IT in schools that occurred as a result of attending the event was transitory. Therefore, it is crucial that inspiring, engaging, and empowering computing classes are being offered continuously at all secondary schools.

Mechanical response of aluminium alloy 6061-T6 after CECAP processing

The potential of new designed continues ECAP machine in intermediate industrial scale has been discussed in the present work. The improved mechanical and microstructural properties of processed materials has been investigated on commercial aluminium alloy 6061 in T6 condition. The 6061-T6 sheet was subjected to one, two, three and four passes of ECAP. The results showing the significant improvement of mechanical properties after ECAP processing.

A comparative study of different power system stabilizers for dynamic stability analysis

Power system stabilizers (PSSs) are extensively used to ensure the dynamic stability of power systems through the modulation of excitation signals supplied to synchronous generators. This paper presents a comparative study of two different PSSs: STAB1 and IEEEST. The stabilizers are designed for the linearized model of a single machine infinite bus (SMIB) system with different loads. Both time-and frequency-domain simulations are carried out to investigate the performance of these stabilizers. For all PSSs, the time-domain simulations are performed by applying a three-phase short-circuit fault at the terminal of the synchronous generator. These simulation results are compared against the open-loop characteristics of the SMIB system where no PSS is implemented. Simulation results demonstrate that the speed-fed PSS provides more damping as compared to frequency- and power-fed stabilizers.

Maternal dietary intake and physical activity habits during the postpartum period: associations with clinician advice in a sample of Australian first time mothers

BACKGROUND: Numerous health benefits are associated with achieving optimal diet and physical activity behaviours during and after pregnancy. Understanding predictors of these behaviours is an important public health consideration, yet little is known regarding associations between clinician advice and diet and physical activity behaviours in postpartum women. The aims of this study were to compare the frequency of dietary and physical activity advice provided by clinicians during and after pregnancy and assess if this advice is associated with postpartum diet and physical activity behaviours.

METHODS: First time mothers (n = 448) enrolled in the Melbourne InFANT Extend trial completed the Cancer Council of Australia's Food Frequency Questionnaire when they were three to four months postpartum, which assessed usual fruit and vegetable intake (serves/day). Total physical activity time, time spent walking and time in both moderate and vigorous activity for the previous week (min/week) were assessed using the Active Australia Survey. Advice received during and following pregnancy were assessed by separate survey items, which asked whether a healthcare practitioner had discussed eating a healthy diet and being physically active. Linear and logistic regression assessed associations of advice with dietary intake and physical activity.

RESULTS: In total, 8.6 % of women met guidelines for combined fruit and vegetable intake. Overall, mean total physical activity time was 350.9 ± 281.1 min/week. Time spent walking (251.97 ± 196.78 min/week), was greater than time spent in moderate (36.68 ± 88.58 min/week) or vigorous activity (61.74 ± 109.96 min/week) and 63.2 % of women were meeting physical activity recommendations. The majority of women reported they received advice regarding healthy eating (87.1 %) and physical activity (82.8 %) during pregnancy. Fewer women reported receiving healthy eating (47.5 %) and physical activity (51.9 %) advice by three months postpartum. There was no significant association found between provision of dietary and/or physical activity advice, and mother's dietary intakes or physical activity levels.

CONCLUSIONS: Healthy diet and physical activity advice was received less after pregnancy than during pregnancy yet no association between receipt of advice and behaviour was observed. More intensive approaches than provision of advice may be required to promote healthy diet and physical activity behaviours in new mothers.

A nonlinear adaptive backstepping approach for coordinated excitation and steam-valving control of synchronous generators

Steam-valving and excitation systems play an important role to maintain the transient stability of power systems with synchronous generators when power systems are subjected to large disturbances and sudden load changes. This paper presents a nonlinear adaptive backstepping approach for controlling excitation and steam-valving systems of synchronous generators. In this paper, the proposed excitation and steam-valving controllers are designed in a coordinated manner so that they can work under several and most severe operating conditions. Both excitation and steam-valving controllers are designed by considering some critical parameters as unknown. The effectiveness of the proposed coordinated control scheme is evaluated on a single machine infinite bus system under different operating conditions such as load changes and three-phase short circuit faults at the generator terminal. Finally, performance of the proposed scheme is compared to that of a similar nonlinear adaptive backstepping excitation controller without any coordination and simulation results demonstrate the superiority of the proposed one.

Nonlinear excitation control of synchronous generators based on adaptive backstepping method

n this paper, the design of a nonlinear excitation control of a synchronous generator is presented where the generator is connected to a single machine infinite bus (SMIB) system. An adaptive backstepping method is used to design the excitation controller with an objective of enhancing the overall dynamic stability of the SMIB system under different contingencies. In this paper, two types of contingencies are considered- i) unknown parameters and physical quantities during the controller design process and ii) controller performance evaluation under different system configurations such as three-phase short circuit faults. The adaption law, which is mainly based on the formulation of Lyapunov function, is used to estimate the unknown parameters which guarantee the convergence of different physical quantities of synchronous generators, e.g., the relative speed, terminal voltage, etc. The effectiveness of the proposed scheme is evaluated under different system configurations as mentioned in the second contingency and compared to that of an existing adaptive backstepping controller and a conventional power system stabilizer (PSS). Simulation results demonstrate the superiority of the proposed control scheme over the existing controllers.

Nonlinear adaptive excitation controller design for multimachine power systems

This paper presents a nonlinear adaptive excitation control scheme to enhance the dynamic stability of multimachine power systems. The proposed controller is designed based on the adaptive backstepping technique where the mechanical power input to the generators and the damping coefficient of each generator are considered as unknown. These unknown quantities are estimated through the adaption laws. The adaption laws are obtained from the formulation of Lyapunov functions which guarantee the convergence of different physical quantities of generators such as the relative speed, terminal voltage, and electrical power output. The proposed scheme is evaluated by applying a three-phase short-circuit fault at one of the key transmission lines in an 11-bus test power system and compared with an existing backstepping controller and conventional power system stabilizer (CPSS). Simulation results show that the proposed scheme is much more effective than existing controllers.

O efeito manada nos fundos de investimento no Brasil: um teste em finanças comportamentais

Utilizando-se de uma amostra de movimentações diárias de fundos de investimento em ações, multimercados e renda fixa no Brasil, por meio de uma metodologia baseada na direção das captações líquidas de um grande número de fundos de investimento, agregados em grupos de investidores de acordo com o porte médio de seu investimento (ricos e pobres), foi encontrada forte evidência da ocorrência de efeito manada de forma heterogênea entre diferentes grupos de investidores, sendo que a intensidade do efeito manada varia de acordo com o porte do investidor, tipo de fundo e com a época. Também foi testado um viés de heurística: a ancoragem de preço, que supõe que após uma nova máxima ou mínima histórica nos preços das ações, haverá uma movimentação anormal de investidores, que acreditam ser este evento um indicador sobre os preços futuros. Encontrou-se evidência de que este fenômeno ocorre em diferentes tipos de fundos de investimento, não apenas os fundos de investimento em ações, e que tem maior impacto quando há uma nova mínima do que quando há uma cotação recorde no índice Ibovespa. Entretanto, o poder de explicação deste viés sobre o efeito manada é pequeno, e há uma série de variáveis ainda não exploradas que têm maior poder de explicação sobre o efeito manada. Desta maneira, este estudo encontrou evidências de que os pressupostos de finanças comportamentais de que a informação e as expectativas dos investidores não são homogêneas, e que os investidores são influenciáveis pelas decisões de outros investidores, estão corretos, mas que há fraca evidência que o viés de heurística de ancoragem de preço tenha papel relevante no comportamento dos investidores.

Obtenção de conceitos no indivíduo e no grupo

O objetivo deste trabalho foi comparar o desempenho de indivíduos e grupos e verificar a influência do tamanho do grupo na solução de problemas sobre a obtenção de conceitos conjuntivos, apresentados através do paradigma de recepção. Usou-se como variável independente o tamanho do grupo, com três níveis: grupos de dois, três e quatro elementos. Os principais resultados encontrados foram: 1) Os grupos de três e quatro elementos apresentaram um desempenho (número de problemas resolvidos corretamente) significantemente superior aos individuos. 2) Não se observaram diferenças significativas de desempenho entre os grupos de dois e os indivíduos. 3) Os grupos de três e quatro elementos apresentaram um desempenho significantemente superior aos grupos de dois. 4) Não se observaram diferenças significativas de desempenho entre os grupos de três e quatro elementos. O modelo A de Lorge e Solomon (1955), segundo o qual o desempenho do grupo reflete o desempenho de seu membro mais apto, foi usado para interpretar os resultados obtidos.

Efetividade do clareamento dentário com peróxido de carbamida a 10% e avaliação dos efeitos adversos sobre o esmalte dentário

The aim of the present study was to assess the effectiveness and adverse effects on dental enamel caused by nightguard vital bleaching with 10% carbamide peroxide. This was accomplished through the interaction of researchers from different areas such as dentistry, materials engineering and physics. Fifty volunteers took part in the doubleblind randomized controlled clinical trial. They were allocated to an experimental group that used Opalescence PF 10% (OPA) and a control group that used a placebo gel (PLA). Fragments of human dental enamel from the vestibular surface of healthy premolars, extracted for orthodontic reasons, were fixed to the vestibular surface of the first upper molars of the volunteers for in situ observation. Bleaching was performed at night for 21 days. The observation periods included Baseline (BL), T0 (21 days), T30 (30 days after treatment) and T180 (180 days after treatment, only for the OPA group). Tooth color was assessed by comparing it with the Vita® scale and by the degree of satisfaction expressed by the volunteer. We also assessed adverse clinical effects, dental sensitivity and gingival bleeding. The study of adverse effects on enamel was conducted in vivo and in situ, using the DIAGNOdent® laser fluorescence device to detect mineral loss. Scanning electron microscopy (SEM) was used to check for superficial morphological alterations, energy dispersive spectrophotometry (EDS) to semiquantitatively assess chemical composition using the Ca/P ratio, and the x-ray diffraction (XRD) technique to observe alterations in enamel microstructure. The results showed that nightguard vital bleaching with 10% carbamide peroxide was effective in 96% of the cases, versus 8% for the PLA group. Dental sensitivity was present in 36% (9/25) of the cases. There was no significant association between gingival bleeding and the type of gel used (p = 1.00). In vivo laser fluorescence analysis showed no difference in values for the control group, whereas in the OPA group there was a statistically significant difference between baseline values in relation to the subsequent periods (p<0.01), with lower mean values for post-bleaching times. There was a significant difference between the groups for times T0 and T30. Micrographic analysis showed no enamel surface alterations related to the treatment performed. No significant alteration in Ca/P ratio was observed in the OPA group (p = 0.624) or in the PLA group (p = 0.462) for each of the observation periods, nor between the groups studied (p=0.102). The XRD pattern for both groups showed the presence of three-phase Hydroxyapatite according to JCPDS files (9-0432[Ca5(PO4)3(OH)], 18-0303[Ca3(PO4)2.xH2O] and 25-0166[Ca5(PO4)3(OH, Cl, F)]). No other peak associated to other phases was found, independent of the group analyzed, which reveals there was no disappearance, nucleation or phase transformation. Neither was there any alteration in peak pattern location. With the methodology and protocol used in this study, nightguard vital bleaching with 10% carbamide peroxide proved to be an effective and safe procedure for dental enamel

Correlations between thermal environment and egg quality of two layer commercial strains

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morfologia floral e biologia reprodutiva de genótipos de aceroleira

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)