In situ degradability of conventional and unconventional starch sources for ruminants,and factors determining their washable fraction: methodological implications

BACKGROUND: The in situ technique (IS) is used for characterising, screening and evaluating feedstuffs in ruminants. However, it is often not adapted to the particular characteristics of feeds (i.e. kinetics of starchy feeds with a standard framework used in forage). This may lead to potential biases in the final conclusions. In two successive experiments, we evaluated the degradative characteristics of conventional (CON) and unconventional (UNC) starchy feedstuffs (ING) and factors affecting their washable fractions (WF). The suitability of IS was then assessed. RESULTS: Two well‐defined ruminal fermentation patterns (CON and UNC) were observed. The WF and insoluble washable (ISWF) fractions were affected by ING, state of presentation [WAY, fresh (F) or pre‐dried (D)], particle size (PSI) and their interactions. The UNC and F feeds had greater WF and ISWF than CON and D, respectively. Increasing PSI linearly reduced WF and its proportion of ISWF. CONCLUSION: The PSI and WAY are critical factors to consider when designing experiments for the evaluation of starchy feedstuffs for ruminants using IS. It is still very risky to propose ‘standard’ parameters as this will always depend on the particular ING evaluated. Conducting pre‐evaluation tests before implementing each research protocol could help to refine the procedure. Copyright © 2009 Society of Chemical Industry     

Fungal pretreatment of wheat straw: Effects on the biodegradability of cell walls,structural polysaccharides,lignin and phenolic acids by rumen microorganisms

Disappearance of cell wall components of untreated straw and straw treated with the ligninolytic white-rot fungi Phanerochaete chrysosporium, Dichomitus squalens and Cyathus stercoreus were determined during the course of rumen digestion of samples in nylon bags. The first fungus degraded hemicelluloses and cellulose non-selectively, adversely affecting the digestion rate of crude cell walls. Dichomitus squalens and C. stercoreus preferentially degraded hemicelluloses and lignin, affording cell wall degradation rates 1.5 times higher than in native straw. Furthermore, the extent of cell wall digestion was also significantly enhanced. Both strains improved the extent of cellulose digestion, whereas the potentially degradable xylan fraction remained unchanged. Polysaccharide digestion rates were influenced in different ways depending on the strain tested: straw degraded by C. stercoreus showed an increase in cellulose digestion rate by 50%, whereas residual arabinose units were slowly degraded. Xylan was degraded 1.8 times faster in straw decayed' by D. squalens, while cellulose digestion remained unchanged. Phanerochaete chrysosporium depressed both xylan and cellulose digestion rates. Fungal-treated lignins were solubilised in the rumen faster than in untreated straw, whereas only treatment by C. stercoreus resulted in higher lignin losses. Esterified phenolic acids were extensively degraded by all three fungi. Residual ferulic and p-coumaric acids accumulated during rumen digestion, although only the former decreased in the original straw.     

The dynamics of aroma release during consumption of candies of different structures,and relationship with temporal perception

We investigated the role of both candy texture and eating technique (melting or chewing) on the dynamics of aroma release. One novelty of this type of analysis was the simultaneous application of instrumental and sensory analysis. Four candy textures were established based on their storage modulus at 1 Hz by varying the gelatine content between 0 and 15% w/w. The invivo release of three aroma compounds was monitored using Proton Transfer Reaction Mass Spectrometry and with a trained panel of testers. The gelatine content had no significant effect on the headspace/product partition and diffusion properties of the aroma compounds. The highest invivo release for all aroma compounds was obtained with the 2% gelatine sample. Our findings indicated that aroma release was determined by interaction between the product properties and oral behaviour. Relations between the dynamics of release and perception (method of Temporal Dominance of Sensations) have been established on temporal parameters.     

Search for the optimal schedule for the oxaliplatin/5-fluorouracil association modulated or not by folinic acid: preclinical data

The combination of oxaliplatin (LOHP)-5-fluorouracil (FU)-folinic acid (FA) has provided high response rates in pretreated patients with advanced colorectal cancer that is resistant to FU-FA. However, the choice of the optimal schedule between LOHP, FU, and FA remains open. The purpose of the present study was to compare, at equivalent drug area under the curve, different schedules for the LOHP-FU +/- FA combinations on four human colorectal cancer cell lines. FU +/- FA was tested as a 2-h short exposure ("bolus"), a 118-h continuous exposure ("infusion"), or a 22-h mixed exposure ("De Gramont protocol"). LOHP was administered for 2 h before, during, or after FU +/- FA exposure. Isobologram analyses revealed that LOHP associated with FU +/- FA resulted in synergistic cytotoxic effects whatever the tested schedules (in > or = 75% of cases). For the FU-LOHP combination, cytotoxicity was significantly different according to the FU exposure type (short > mixed > continuous) and was independent of the LOHP position. In contrast, for the FU-FA-LOHP combination, neither the FU exposure type nor the LOHP position significantly influenced cytotoxicity. The presence of FA significantly enhanced the cytotoxicity of FU-LOHP (P < 0.001); this potentiation was independent of the FU exposure type and was significantly influenced by the LOHP position (LOHP after FU-FA > LOHP during FU-FA > LOHP before FU-FA). In conclusion, in contrast with the recognized superiority of continuous FU exposure over short exposure when the drug is given alone, the FU-LOHP combination is more cytotoxic when FU is given as a short exposure. This suggests the potential interest of such a schedule in the clinical setting.     

Health status recovery at one year in children injured in a road accident: A cohort study

Despite the frequency of traumatic injuries due to road accidents and potential importance of identifying children at risk of impaired recovery one year after a road accident, there is a lack of data on long-term recovery of health status, except in children with severe traumatic brain injury. The aim of the present study was to evaluate predictive factors of recovery in children one year after road traffic injuries. The prospective cohort study was composed of children aged <16 years, admitted to public or private sector hospitals in the Rhône administrative area of France following a road accident. Recovery of health status one year after the accident and information concerning quality of life and the consequences of the accident for the child or family 1 year after the accident were collected by questionnaire, usually completed by the parents. Victims were in majority male (64.6%) and had mild or moderate injuries (81.9% with Maximum Abbreviated Injury Scale (M-AIS) <3). One year after the accident, 75.0% of the mild-to-moderate and 34.8% of the severe cases estimated health status as fully recovered. After adjustment, severity score (M-AIS ≥ 3) and lower limb injury (AIS > 1) were associated with incomplete recovery of health status: weighted odds ratio (OR_w), 4.3 [95% confidence interval (95% CI), 1.3–14.6] and OR_w, 6.5 [95% CI, 1.9–21.7], respectively. Recovery status correlated significantly with quality of life physical scores (r = 0.46), especially body pain (r = 0.48) and role/social–physical (r = 0.50) and, to a lesser extent, quality of life psychosocial scores (r = 0.21). In a cohort of children injured in a road accident, those with high injury severity score and those with lower limb injuries are less likely to recover full health status by 1 year. Impaired health status was associated with a lower physical quality of life score at 1 year.     

Periodic event‐triggered observation and control for nonlinear Lipschitz systems using impulsive observers

In this paper, we investigate the observation and stabilization problems for a class of nonlinear Lipschitz systems, subject to network constraints, and partial state knowledge. In order to address these problems, an impulsive observer is designed, making use of the event‐triggered technique in order to diminish the network communications. Sufficient conditions are given to ensure a milder version of the separation principle for these systems, controlled via an event‐triggered controller. The proposed observer ensures practical state estimation, while the corresponding dynamic controller ensures practical stabilization. The sampling and the data transmission are carried out asynchronously. The dynamic controller is tested in simulation on a flexible joint. Copyright © 2017 John Wiley & Sons, Ltd.     

Remotely sensed surface water extent as an indicator of short-term changes in ecohydrological processes in sub-Saharan Western Africa

The highly variable rainfall in the arid and semi-arid regions of sub-Saharan Western Africa drives both surface water availability and vegetation cover. Recent studies have established linkages between rainfall and vegetation cover at local to regional scales, but no study related yet remote sensing derived rainfall and vegetation cover to the available surface water. A new dataset based on SPOT VEGETATION (VGT) represents surface water bodies (SWB) in the arid and semi-arid regions of sub-Saharan Western Africa. Water bodies represent the integrated hydrological response of a catchment, and changes in their spatial extent involve complex interactions at the catchment scale. We analyzed time series of remotely sensed vegetation cover, rainfall and surface water extent for the period 1999–2008, and could detect and statistically demonstrate the links between these biophysical variables. Our findings for two regions in Mali and Burkina Faso suggest that vegetation cover is positively related to the amount of available surface water for those catchments that are mainly covered by annual plants. The observed relationships between remotely sensed variables allow developing ecological indicators that can indicate short-term changes in arid and semi-arid ecosystems at local to regional scales.