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The effect of weight gain during mid- and late gestation in dairy heifers on performance at the start of first lactation was studied. In this experiment, 47 Holstein heifers with first calving at 36 months of age were used. The plane of nutrition aimed to have a high (900 g/d, H; n = 23) and low (500, L; n = 24) average daily gain (ADG) from the 4th month of gestation until 3 weeks before the expected day of calving, achieved by ad libitum intake of high quality pasture (H) or controlled intake of a total mixed ration (L). Body weight (BW), body condition score (BCS), milking, and reproductive performances were recorded. Concentrations of plasma non-esterified fatty acids (NEFA), glucose, beta-hydroxybutyric acid (BHBA), and urea were characterised at weeks 2, 4, 6 and 8 of lactation. Milk fatty acid composition was determined at weeks 3 and 6. A total of 39 heifers successfully calved and completed first lactation. During feeding treatment the required ADG were achieved. BW and BCS were higher in H heifers at calving compared to L heifers: 707 vs. 640 kg, and 3.91 vs. 3.01 respectively. H heifers lost more weight, BCS and had lower feed intake during the beginning of first lactation (−0.8 kg DM/d/heifer over the first 4 weeks of lactation). Per day of lactation, H heifers produced significantly more milk (29.2 vs. 26.2 kg), fat (1.27 vs. 1.07 kg) and protein (0.84 vs. 0.477 kg) from 0 to 8 weeks of lactation. Concentrations of NEFA, glucose and BHBA were higher in H heifers compared to L heifers, but urea concentration was not affected. Concentration of preformed fatty acids in the milk (C16 and more) was higher. As a result, the calculated daily net energy balance during the first 8 weeks of lactation was −1.53 and −5.95 MJ for L and H heifers, respectively.
Weeds are often spatially aggregated in maize fields, and the level of
aggregation varies across and within fields. Several annual weed species are
present in maize fields before postemergence herbicide application, and
herbicides applied will control several species at a time. The goal of this
study was to assess the spatial distribution of multispecies weed
infestation in maize fields. Ground-based imagery was used to map weed
infestations in rain-fed maize fields. Image segmentation was used to
extract weed cover information from geocoded images, and an expert-based
threshold of 0.102% weed cover was used to generate maps of weed
presence/absence. From 19 site-years, 13 (68%) demonstrated a random spatial
distribution, whereas six site-years demonstrated an aggregated spatial
pattern of either monocotyledons, dicotyledons, or both groups. The results
of this study indicated that monocotyledonous and dicotyledonous weed groups
were not spatially segregated, but discriminating these weed groups slightly
increased the chances of detecting an aggregated pattern. It was concluded
that weeds were not always spatially aggregated in maize fields. These
findings emphasize the need for techniques allowing the assessment of weed
aggregation prior to conducting site-specific weed management.
Hip or knee arthroplasty infection (HKAI) leads to heavy medical consequences even if rare.
To assess the routine use of a hospital discharge detection algorithm of prosthetic joint infection as a novel additional tool for surveillance.
A historic 5-year cohort study was built using a hospital database of people undergoing a first hip or knee arthroplasty in 1 French region (2.5 million inhabitants, 39 private and public hospitals): 32,678 patients with arthroplasty code plus corresponding prosthetic material code were tagged. HKAI occurrence was then tracked in the follow-up on the basis of a previously validated algorithm using International Statistical Classification of Disease, Tenth Revision, codes as well as the surgical procedures coded. HKAI density incidence was estimated during the follow-up (up to 4 years after surgery); risk factors were analyzed using Cox regression.
A total of 604 HKAI patients were identified: 1-year HKAI incidence was1.31%, and density incidence was 2.2/100 person-years in hip and 2.5/100 person-years in knee. HKAI occurred within the first 30 days after surgery for 30% but more than 1 year after replacement for 29%. Patients aged 75 years or older, male, or having liver diseases, alcohol abuse, or ulcer sore had higher risk of infection. The inpatient case fatality in HKAI patients was 11.4%.
The hospital database method used to measure occurrence and risk factors of prosthetic joint infection helped to survey HKAI and could optimize healthcare delivery.
Infect Control Hosp Epidemiol 2015;36(10):1198–1207
The implementation of site-specific weed management requires information about weed cover and decision support systems to determine weed cover thresholds and concomitant herbicide rates. Although it is possible to create accurate weed cover maps over large areas, weed cover thresholds have generally been evaluated using tedious weed density counts. To bridge this gap between weed cover obtained by machine vision and the concept of economic threshold, crop advisers specializing in weed scouting were asked to evaluate over 2,500 weed cover images (2 m by 3 m) and determine if a given image would require herbicide application or not. Using the area under the “receiver operating characteristic” curve method, an optimal weed cover threshold was established. The derived economic thresholds ranged from 0.06 to 0.31% weed cover contingent on the level of tolerance of the expert adviser. Although this threshold seems low, it is comparable with economic threshold values based on weed density.
Catherine Esnouf, Institut National de la Recherche Agronomique (INRA), Paris,Marie Russel, Institut National de la Recherche Agronomique (INRA), Paris,Nicolas Bricas, Centre de Co-opération Internationale en Recherche Agronomique pour le Développement (CIRAD), Paris
Regional and global food systems are constantly evolving, thus the contextual elements presented in Chapter 1 are likely to evolve, and food systems will be transformed. Because it is impossible to predict the food systems of tomorrow, we have adopted a foresight approach in order to try and understand possible future changes. Our approach, which is presented in the first part of this chapter, has therefore mainly been based on identifying the main drivers of the transformation of food systems. This work was the fruit of collective discussions by a multidisciplinary group made up of some 15 experts. The plurality of their views and their areas of competence allowed them to analyse the potential impacts of the different evolutions identified relative to the sustainability of food systems in terms of their nutritional, economic, social, cultural, environmental and territorial dimensions. This step of the analysis also enabled us to highlight a certain number of points at issue, which are presented in the second part of the chapter; this does not end with a presentation of different scenarios (as might have been expected), but concludes with the three transversal messages arising from debate by this workshop: issues linked to inequalities of access to food, territorial dynamics and the governance of food systems.
Food systems evolving under the effects of various factors
Through the identification of factors underlying the transformation of food systems, it appears clearly that some trends have already been identified (see, in particular, Chapter 1 on the context and the challenges of food systems, and the retrospective analysis described in Chapter 2). Nevertheless, these trends involve a certain number of questions and uncertainties, notably regarding the nature and degree of their potential effects. These uncertainties thus open the way to contrasting scenarios for food systems throughout the world (see Figure 9.1).
New sedimentological, biostratigraphical and geochemical data recording the Toarcian Oceanic Anoxic Event (T-OAE) are reported from a marginal marine succession in southern Beaujolais, France. The serpentinum and bifrons ammonite zones record black shales with high (1–10 wt%) total organic carbon contents (TOC) and dysoxia-tolerant benthic fauna typical of the ‘Schistes Carton’ facies well documented in contemporaneous nearby basins. The base of the serpentinum ammonite zone, however, differs from coeval strata of most adjacent basinal series in that it presents several massive storm beds particularly enriched in juvenile ammonites and the dysoxia-tolerant, miniaturized gastropod Coelodiscus. This storm-dominated interval records a marked negative 5‰ carbonate and organic carbon isotope excursion being time-equivalent with that recording storm- and mass flow-deposits in sections of the Lusitanian Basin, Portugal, pointing to the existence of a major tempestite/turbidite event over tropical areas during the T-OAE. Although several explanations remain possible at present, we favour climatically induced changes in platform morphology and storm activity as the main drivers of these sedimentological features. In addition, we show that recent weathering, most probably due to infiltration of O2-rich meteoric water, resulted in the preferential removal of 12C-enriched organic carbon, dramatic TOC loss and total destruction of the lamination of the black shale sequence over most of the studied exposure. These latter observations imply that extreme caution should be applied when interpreting the palaeoenvironmental significance of sediments lacking TOC enrichment and lamination from outcrops with limited surface exposures.
At the field scale, weeds generally appear aggregated rather than randomly distributed, and this aggregation is linked to the spatial heterogeneity of biotic and abiotic factors. Crop management practices shape the spatial pattern of weed infestations by modifying certain factors having an impact on weed emergence and growth. Although crop seeding is often the last in-field disturbance before crop and weed emergence, its effect on the distribution of weeds has received little attention in the literature. The purpose of this study was to assess the influence of the planting operation on weed cover and presence in corn fields using digital images to investigate the possibility of sensing the interrow to infer the presence or absence of weeds on the corn row. A total of 18 site-years under conventional tillage treated with a single POST application of herbicide were selected across seven locations. Image analysis, at the V2 to V4 growth stage of corn, was used to compare the weed cover in three zones: the undisturbed interrows, the corn rows, and the interrows compacted by tractor wheel traffic. For 61% of site-years, there was no significant difference among the zones. When there was a significant difference compared with the other two zones, the undisturbed interrow was usually less infested. Point-to-point comparisons of weed presence or absence (based on a threshold of five pixels) between the interrow and the corn row revealed 70 or 73% correspondence, depending on the type of interrow (undisturbed or tracked). However the error of inference of the corn row weed cover generated by sensing only adjacent interrows may be too high for efficient commercial weed control.
Care-related infections are a major public health concern. Their transmission can be associated with environmental factors. This study looks at air contamination around 45 patients colonized with multidrug-resistant organisms (MDROs). We found that 30 hospital rooms (67%) were contaminated with MDRO species and 10 rooms (22%) were contaminated with at least 1 MDRO.
Weed management decisions based on weed threshold models offer the opportunity to reduce herbicide use by allowing the possibility of forgoing treatment or lowering rates. Weed thresholds based on a relative leaf-cover model were tested during a 4-yr period at two locations. Two 1.62-ha fields, planted to conventional and glyphosate-resistant corn (2004, 2005, 2007) or soybean (2006), were divided in 900 m2 sections. Herbicides were applied postemergence to each of these sections with either variable rates based on weed thresholds, or constant full rates. Variable herbicide rates included: no application, half rate, or full rate. Relative weed cover values of 0.2 and 0.4 (corn) or 0.1 and 0.3 (soybean) served as thresholds for incremental rates. Digital images were used to evaluate the relative weed cover. Weed density was assessed before and after herbicide application. Weed seed production was estimated for two species in 2004 and 2005. No difference in crop yield, relative weed cover, weed density, or weed seed production was observed between conventional and glyphosate-resistant cropping systems. During the first year, herbicide use reduction was obtained (−85.4%) with marginal crop yield loss (5 to 15%). In the subsequent 3 yr, preherbicide weed densities increased and concomitant increases in relative weed cover values did not allow more than a 10% overall reduction in herbicide use. This threshold model designed to maintain crop yields within a given year did not allow significant reduction in herbicide use during the following 3 yr. Residual weed populations most likely replenished the seed bank to levels that allowed weed densities to increase afterward. Increased weed density over time in plots treated with full rates of herbicide every year also indicated that a single postemergence herbicide treatment was not sufficient to contain weed populations at low levels every year in this corn–soybean rotation.
Le présent article traite des interactions
fluide/structure dans le domaine des moyennes fréquences. En effet, dans
ce domaine fréquentiel, il n'est pas possible de modéliser un
système fluide/structure en FEM car la densité modale du milieu
fluide est trop importante, ni de le modéliser en SEA car cette
modélisation ne serait pas valide. Une méthode hybride FEM/SEA est
donc développée : la méthode SEA-like. La méthode SEA-like
est une méthode énergétique dont la matrice est calculée
avec des méthodes de type "basses fréquences". Les coefficients
SEA-like sont calculés avec une condensation dynamique afin de prendre
en compte la densité modale importante dans le système. Dans cet
article, la matrice SEA-like d'un système couplé plaque/cavité
est calculé avec une analyse modale. On obtient alors une expression
simplifiée des coefficients SEA-like. La matrice SEA-like est alors
validée dans le domaine des basses fréquences avec modélisation
FEM du système couplé et dans le domaine des hautes fréquences
avec une modélisation SEA du système couplé.
Anthocyanins are natural dietary pigments with a wide array of biological properties that are possibly involved in the prevention of various diseases. These properties depend on their absorption and metabolism in the body. In the present study we first examined the gastric and intestinal absorption of pelargonidin 3-glucoside (Pg 3-glc) using rat in situ models. A high proportion of Pg 3-glc was rapidly absorbed from both the stomach (23 %) and small intestine (24 %). Its metabolism was further studied by feeding rats during 8 d with a diet enriched in freeze-dried strawberries. Only low amounts of total anthocyanins were recovered in 24 h urine (0·163 (sem 0·013) % of ingested anthocyanins; n 8). Strawberry anthocyanins were analysed in urine by HPLC-electrospray ionisation-tandem MS. Similar proportions of intact glycosides (about 53 %) and glucuronidated metabolites (about 47 %) were found. Pg 3-glc was thus glucuronidated to a larger extent than cyanidin 3-glucoside. These results highlight the influence of the aglycone structure on anthocyanin metabolism.
The aim of the present study was to assess the respective contributions of regional and socio-economic factors to dietary pattern. We used the data from the final MONICA (MONItoring of trends and determinants in Cardiovascular disease) population survey conducted in the three French centres in 1995–7 among a representative sample of 976 men aged 45–64 years. Dietary intake was assessed using a 3-d record method. Dietary patterns were identified by a factor analysis, based on fifteen food items. An analysis of variance was then used to study their relationship with regional and socio-economic determinants. Two major dietary patterns were identified: a ‘Western diet’, characterized by high intakes of sugar and sweets, grains, butter, added fats, eggs, potatoes and cheese; a ‘prudent diet’, mainly distinguished by high intakes of fruit, vegetables, olive oil and fish and low intakes of alcohol, high-fat meat and potatoes. Strong associations were mostly observed with the ‘prudent diet’ pattern, with a significant relationship with region, educational and income-tax levels, leisure-time physical activity and smoking status. There was also a statistically significant interaction between region and educational level (P=0·05), and between region and income-tax level (P=0·03), indicating that the influence of socio-economic factors is different among regions. In conclusion, these results indicate large regional and socio-economic differences in the dietary patterns of this French male population. When considering the ‘prudent diet’ pattern, they also suggest that traditional regional influences may now be overcome by socio-economic determinants.
The survival of female Anopheles gambiae s.s. mosquitoes inside two village house types (grass-thatched and iron-roofed) was studied in relation to diet and ambient indoor microclimatic conditions. Two batches of 20–30, 1-day-old laboratory-bred mosquitoes were maintained inside cages in the grass-thatched (n=2) and iron-roofed (n=2) houses and fed daily, one group on 10% glucose and the other on human blood. Throughout the experiments, indoor temperature and relative humidity of the houses were recorded, and mortality of mosquitoes monitored daily until all had died. The experiments were replicated thrice. There was no significant variation in the overall mean temperature (P=0.93) or relative humidity profiles (P=0.099) between the two house types, although the iron-roofed houses recorded higher temperature peaks. A Kaplan–Meier survival analysis showed that the mean survival times of mosquitoes were 8 and 10 days in the two grass-thatched huts and 7 and 10 days in the two iron-roof houses for mosquitoes feeding on blood and sugar meals, respectively. The mean survival times of mosquitoes maintained inside similar house types differed only due to diet. In the proportionality of hazards model (Cox regression), the dietary regimes significantly influenced the probability of survival (P=0.0001), with mosquitoes surviving longer on sugar meals than on blood. Microclimatic factors inside houses also significantly influenced mosquito survival. Although higher peak temperatures were recorded in corrugated iron-roofed houses, the survival of the mosquitoes resting in them did not differ significantly from that in grass-thatched houses. However, the impact of these temperatures on the development of malaria parasites inside the vector needs to be investigated.