RESUMO
Single-point measurements from towers in cities cannot properly quantify the impact of all terms in the turbulent kinetic energy (TKE) budget and are often not representative of horizontally-averaged quantities over the entire urban domain. A series of large-eddy simulations (LES) is here performed to quantify the relevance of non-measurable terms, and to explore the spatial variability of the flow field over and within an urban geometry in the city of Basel, Switzerland. The domain has been chosen to be centered around a tower where single-point turbulence measurements at six heights are available. Buildings are represented through a discrete-forcing immersed boundary method and are based on detailed real geometries from a surveying dataset. The local model results at the tower location compare well against measurements under near-neutral stability conditions and for the two prevailing wind directions chosen for the analysis. This confirms that LES in conjunction with the immersed boundary condition is a valuable model to study turbulence and dispersion within a real urban roughness sublayer (RSL). The simulations confirm that mean velocity profiles in the RSL are characterized by an inflection point z γ located above the average building height z h . TKE in the RSL is primarily produced above z γ , and turbulence is transported down into the urban canopy layer. Pressure transport is found to be significant in the very-near-wall regions. Further, spatial variations of time-averaged variables and non-measurable dispersive terms are important in the RSL above a real urban surface and should therefore be considered in future urban canopy parametrization developments.
RESUMO
AIM: The aim of the study was to assess the consequences of early and systematic nutritional intervention on the clinical conditions of amyotrophic lateral sclerosis (ALS) patients and on the opportunity to maintain a good nutritional status for as long as possible. METHODS: Thirty-three subjects with ALS. Protocol Group: 12 subjects (9 M and 3 F) monitored according to a precise nutritional intervention protocol. CONTROL GROUP: 21 subjects (10 M and 11 F) monitored before applying the protocol. RESULTS: Data recorded at the time of initial assessment were compared and expressed as the mean ± standard deviation for the Protocol Group vs. the CONTROL GROUP: BMI (kg/m2) 23.6 ± 4.1 vs. 21.6 ± 3.5; weight loss as a percentage of usual weight 6.6 ± 7.9 vs. 16.3 ± 8.8 (P=0.003). At six months: weight loss as a percentage of usual weight 4.9 ± 6.2 vs. 16.9 ± 10.2 (P=0.002). At 12 months: weight loss as a percentage of usual weight 7.3 ± 7.1 vs. 17.5 ± 11.1 (P=0.03). At the first follow-up visit, fewer patients in the Protocol Group were receiving enteral nutrition (25%) than patients in the CONTROL GROUP (60%). At six-month follow-up visit: 30% vs. 68%. Standard enteral nutrition formulas were used. One year after initial assessment, the mortality rate was 17% for the Protocol Group, whereas it was 24% at six months and 33% after one year for the CONTROL GROUP. CONCLUSION: If patients are treated before any significant weight loss occurs, early and specific nutritional intervention allows good nutritional status to be maintained for a longer period; if artificial nutrition is required, standard diets are able to ensure adequate clinical results.
