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Objective: To identify predictors of faster time to virological suppression among infants starting combination antiretroviral therapy (cART) early in infancy. Design: Cohort study of infants from Europe and Thailand included in studies participating in the European Pregnancy and Paediatric HIV Cohort Collaboration. Methods: Infants with perinatal HIV starting cART aged less than 6 months with at least 1 viral load measurement within 15 months of cART initiation were included. Multi-variable interval-censored flexible parametric proportional hazards models were used to assess predictors of faster virological suppression, with timing of suppression assumed to lie in the interval between last viral load at least 400 and first viral load less than 400 copies/ml. Results: Of 420 infants, 59% were female and 56% from Central/Western Europe, 26% United Kingdom/Ireland, 15% Eastern Europe and 3% Thailand; 46 and 54% started a boosted protease inhibitor-based or nonnucleoside reverse transcriptase inhibitor-based regimen, respectively. At cART initiation, the median age, CD4(+) % and viral load were 2.9 [interquartile range (IQR): 1.4-4.1] months, 34 (IQR: 24-45)% and 5.5 (IQR: 4.5-6.0) log(10) copies/ml, respectively. Overall, an estimated 89% (95% confidence interval: 86-92%) achieved virological suppression within 12 months of cART start. In multivariable analysis, younger age [adjusted hazard ratio (aHR): 0.84 per month older; P < 0.001], higher CD4(+) % (aHR: 1.11 per 10% higher; P=0.010) and lower log(10) viral load (aHR: 0.85 per log(10) higher; P < 0.001) at cART initiation independently predicted faster virological suppression. Conclusion: We observed a significant independent effect of age at cART initiation, even within a narrow 6 months window from birth. These findings support the earliest feasible cART initiation in infants and suggest that early therapy influences key virological and immunological parameters that could have important consequences for long-term health.

There has been substantial attention in the reliability literature to redundancy and diversity of components in system reliability. It is typically argued that, whilst additional components in parallel system structures provide redundancy and increase system reliability, their positive effect may be restricted due to common-cause failures which possibly affect all components of a particular type. This problem can be overcome through a combination of redundancy and diversity, so the use of components of different types, leaving the system less severely affected by possible common-cause failures. There is a second and perhaps even more important reason for aiming at diversity of components, which appears to have received little attention in the literature. One may have only limited information about component reliability, which causes the random functioning of multiple components of one type in a system to be mutually dependent, resulting in possibly higher risk than may be expected without careful ...

Count-data models are used to analyze the relationship between patents and research and development spending at the firm level, accounting for overdispersion using a finite mixed Poisson regression model with covariates in both Poisson rates and mixing probabilities. Maximum likelihood estimation using the EM and quasi-Newton algorithms is discussed. Monte Carlo studies suggest that (a) penalized likelihood criteria are a reliable basis for model selection and can be used to determine whether continuous or finite support for the mixing distribution is more appropriate and (b) when the mixing distribution is incorrectly specified, parameter estimates remain unbiased but have inflated variances.

The paper deals with the use of computer simulations both for the design support of a new buildings and HVAC system development and for the optimisation of the system control strategy in the building. This is presented on a real office building in Prague. For a new large bank head office in Prague, computer simulations were carried out to find solutions for reducing the required cooling capacity, verify the fan-coil capacity design, and optimise the external gassing for atriums. Because the design included exposed concrete ceilings, the idea was to apply building thermal mass and find out a way to operate the building. The cooling capacity was initially estimated at 3 MW and simulations proved possibility of decreasing it to 81% for the whole building. Other simulation helped designers to optimise, roof glazing and shading for atria, with stress on thermal comfort in open corridors. The building and HVAC system monitoring and meassurements to confirm the simulation based design changes are presented in the paper.

This PhD thesis deals with the applicability of passive and low energy cooling technologies in the Czech Republic. The work includes climate analysis, gains analysis as well as buildings and systems analysis in order to estimate the potential of passive and low energy cooling technologies. The latter detailed design is based on case studies, which include building simulation and some monitoring. The role of computer simulation in low energy building design and optimisation is presented. Low energy cooling technologies provide cooling in an energy efficient manner, thus reducing energy consumption and peak electricity demand. They do so by making use of low quality sources of cooling; whether it is ambient air or ground temperatures or warmer chilled water. Those technologies may be considered passive and hybrid cooling systems. The following low energy cooling technologies are addressed in this thesis: · Night ventilation – lowers the temperature of the building thermal mass using night ventilation · Evaporative cooling – sensible heat is absorbed as a latent heat to evaporate water · Ground cooling – the air is cooled by the ground via matrix of piping or groundwater (aquifer) cooling · Slab cooling – thermal mass of slab is cooled by air or water

The paper deals with the use of computer simulations both for the design support of HVAC systems development in existing industrial buildings. There is presented selected industrial hall and its HVAC systems concept. The computer simulation using ESP-r software for different rates of ventilation by outdoor air helped to design an air-conditioning system, which comprises of daytime top cooling and night ventilation by outdoor air combined with accumulation of cold in building constructions. Capacity of mechanical cooling was decreased to more that 50% comparing to original design based on manual calculation for peak loads. The importance of internal gains measurements and investigation for industrial halls is presented as well.

The paper deals with applicability of passive and low energy cooling technologies in the Czech Republic. In the paper there are presented two recent studies, where computer simulation helps to design properly the passive and low energy cooling for buildings is the Czech Republic. There is presented case studies applying, night cooling, thermal mass and slab cooling. The role of computer simulation in the low energy building design and optimalization is discussed.

En muchas ocasiones se ha tratado sobre la necesidad de optimizar el sistema mecánico nocturno de refrigeración. En este documento se trata de la utilización de simulaciones por ordenador tanto para el apoyo al diseño de un edificio nuevo y desarrollo de un sistema HVAC, como para la optimización de la estrategia para el control del sistema en edificios terminados. En el proyecto inicial de un edificio comercial nuevo en Praga se llevaron a cabo simulaciones por ordenador para probar los posibles efectos de la ventilación nocturna para enfriamiento. Las predicciones del ambiente interior y el consumo de energía para soluciones opcionales, con vistas a las capacidades de enfriamiento (refrigeración) y los diferentes ratios de ventilación mediante el aire exterior, ayudaron a diseñar un sistema de acondicionamiento de aire, que comprende la refrigeración diurna y la ventilación nocturna por aire exterior, combinadas con la acumulación de frío en las construcciones de edificios. Se procedió a una monitorización durante bastante tiempo y ulteriores simulaciones por ordenador con el fin de optimizar la estrategia de control para el sistema de refrigeración diurna.

The need of optimization for the mechanical night cooling system was discussed in many cases. The paper deals with the use of computer simulations both for the design support of a new building and HVAC system development and for the optimization of the system control strategy in the finished building. In early design of a new commercial building in Prague computer simulations were carried out to prove possible effects of night cooling ventilation. Predictions of the indoor environment and energy consumption for optional solutions regarding cooling capacities and different rates of ventilation by outdoor air helped to design an air-conditioning system, which comprises of daytime top cooling and night ventilation by outdoor air combined with accumulation of cold in building constructions. Long-time monitoring and further computer simulations were performed in order to optimize the control strategy for the top cooling system.

Building performance simulation (BPS) is a powerful tool to support building and system designers in emulating how orientation, building type, HVAC system etc. interacts the overall building performance. Currently BPS is used only for code compliance in the detailed design, neither to make informed choices between different design options nor for building and/ or system optimization [Wilde, 2004].BPS could/ should be used in a way of indicating design solutions, introducing an uncertainty and sensitivity analysis and building and/ or system optimization. This research is about enhancing the use of BPS in the detailed design by supporting design and system optimization.

The paper deals with applicability of passive and low energy cooling technologies in the Czech Republic.There are presented climate, buildings and systems analysis, to find out passive and low energy cooling technologies potential. Some case studies including building simulations and monitoring are introduced (the office building with night ventilation, direct evaporative cooling, slab cooling, role of thermal mass in an historical building, thermal lops). The role of computer simulation in the low energy building design and optimalization is discussed.

This paper deals with the passive and low energy cooling technologies in the Czech Republic. The role of computer simulation in low energy building design and optimization is discussed. The work includes buildings and systems analysis as well as climate analysis in order to estimate the potential of passive and low energy cooling technologies. The former is based on case studies, which include both building simulation and monitoring.

This paper deals with the applicability of passive and low energy cooling technologies in the Czech Republic. The work includes climate analysis as well as buildings and systems analysis in order to estimate the potential of passive and low energy cooling technologies. The latter is based on case studies, which include both building simulation and monitoring. The role of computer simulation in low energy building design and optimization is briefly discussed.

This paper deals with the use of computer simulations both for design support of a new building including its heating, ventilation and airconditioning (HVAC) systems and for optimization of the HVAC control strategy during operation of the completed building. In the early design phases for a new commercial building in Prague computer simulations were carried out in view of possible effects of night cooling ventilation. Predictions of the indoor environment and energy consumption for various options regarding cooling capacity and different outdoor ventilation rates supported the HVAC system design which included daytime top cooling and night ventilation with outdoor air combined with accumulation of cold in building constructions. After completion of the building, occupants' complaints and a set of measurements indicated some problems with the HVAC, which were subsequently solved. Long-term monitoring and further computer simulations were performed in order to optimize the control strategy of the top cooling system.

This paper deals with the use of computer simulations both for design support of a new building including its heating, ventilation and air-conditioning (HVAC) systems and for optimization of the HVAC control strategy during operation of the completed building. In the early design phases for a new commercial building in Prague computer simulations were carried out in view of possible effects of night cooling ventilation. Predictions of the indoor environment and energy consumption for various options regarding cooling capacity and different outdoor ventilation rates supported the HVAC system design which included daytime top-cooling and night ventilation with outdoor air combined with accumulation of cold in building constructions. After completion of the building, occupants' complaints and a set of measurements indicated some problems with the HVAC, which were subsequently solved. Long-term monitoring and further computer simulations were performed in order to optimize the control strategy of the top-cooling system.

This research aims to investigate how building energy simulation tools are used in the first design stages, focusing on the design practice of architects willing to obtain the optimal energy performance in order to create sustainable ar.chitecture. We survey in which measure the simulation tools could guide the choices of the designer, if they are used by consultants or by the designers themselves, and which are the main reasons that prevent their use in the common design practice. The research is conduct through these instruments: literature research, research by professional figures -questionnaires- , research through a case study.

Until the 1970’s most office buildings in central Europe were not equipped with mechanical cooling (air-conditioning). Due to increasing requirements for thermal comfort and warmer summers, nowadays mechanical cooling is often applied to such buildings, however without caring for energy consumption and without considering possibilities of low energy or passive cooling. This paper discusses options for incorporating low energy cooling technologies when retrofitting office buildings in central Europe. Climate analysis, design recommendations and role of computer simulation of building and system in the design process are presented. Applicability of night ventilation, evaporative cooling, and cooled ceiling panels, which can provide optimal thermal comfort in a conditioned space in relation to low energy consumption, will be analyzed. The slab cooling using existing slab heating system is stressed in the paper.

This paper attempts to outline the current state-of-the-art regarding the use of building performance simulation as a design tool for refurbishment of buildings. This is illus-trated by means of three recent studies for conversion of historical buildings (an early 20th century factory, and a water mill and a former church both dating back to the 14th century) into an office development, a museum gallery and a concert hall respectively. The paper elaborates the modeling and simulation work that was carried out to support the design teams of the three projects. This includes a discussion on how the simula-tion results were transformed in relevant design information. The paper finishes by indicating directions for future work that is needed to be better equipped in order to address design problems in the field of construction or restoration of buildings and their heating, ventilation and air-conditioning systems.