In vitro pre-exposure of Haemonchus contortus L3 to blood eosinophils reduces their establishment potential in sheep

Different authors have reported that eosinophils are capable of immobilising infective larvae of different species of nematodes in vitro. However, classifying larvae as mobile or immobile is so subjective that it does not always mean all apparently immobile larvae are dead or those that are mobile are capable of surviving further immune responses if administered to their natural hosts. The objective of this experimental study was therefore to substantiate the role of eosinophils in the killing of Haemonchus contortus infective larvae by comparing the infectivity in sheep of larvae that had been incubated with eosinophil-enriched cell suspensions with control larvae. Since it was not possible to isolate pure eosinophils from sheep blood, we were compelled to evaluate the effects of other blood cells contaminating our eosinophil-enriched suspensions. Although eosinophils and neutrophils were the only cells found adherent to H. contortus infective larvae in vitro, induced eosinophils in the presence of immune serum were primarily responsible for the drastic reduction in larval motility compared to the minor effects of neutrophils and mononuclear cells. Corresponding reductions in faecal egg count and worm numbers were observed when the incubated larvae were transferred intra-abomasally to sheep. Interestingly, the proportion of larvae that failed to establish was much higher following incubation with induced eosinophils compared with other cells or with immune serum alone. Although this study did not address the in vivo role of eosinophils in sheep, the results strongly indicate that sheep blood eosinophils have a larval killing potential in vitro, and a larval mobility test alone may not fully explain the level of damage inflicted on the larvae.     

trans-C18:1 isomers in cheeses enriched in unsaturated fatty acids and manufactured with different milk fat globule sizes

Increasing the knowledge on dietary fat composition, mainly the minor components, will improve the nutritional value of foods and their labeling. In this study, we examined the trans-octadecenoic acid (C18:1) composition of Emmental cheeses enriched in unsaturated fatty acids (FA) and manufactured with milks produced by cows selected to produce small and large fat globules. The FA composition of the milks was not significantly ( P > 0.05) different from the FA composition of the corresponding Emmental cheeses. Increasing the unsaturated FA content of the cheeses using dietary manipulations lead to an increase in the trans-C18:1 and changed their isomeric profiles. In milk fat produced with the linseed-enriched diet, the trans-10 C18:1 concentration was greater than trans-11 C18:1 (vaccenic acid), which is classically the major trans-C18:1 in milk fat. The content in trans-C18:1 and more particularly in trans-10 C18:1 was negatively correlated with the size of fat globules ( r (2) = 0. 82 and 0.87, respectively) and related to milk fat depression. The trans-C18:1 content was negatively correlated with the saturated FA (slope = -0.35; r (2) = 0.81) and positively correlated with the unsaturated (slope = 0.29; r (2) = 0.85) and monounsaturated (slope = 0.32; r (2) = 0.81) FA. Focusing on the health-related considerations of fat in food products, further nutritional studies are needed to elucidate the role of trans-C18:1 isomers.     

Competing Visions: Domestic Forests, Politics and Forest Policy in the Central Western Ghats of South India

Rural people in developing countries including India continue to access a number of types of ‘forests’ to meet specific needs such as fuelwood, fodder, food, non-timber forest produce and timber for both subsistence and income generation. While a plethora of terms exist to describe the types of forests that rural people use—such as farm forests, social forests, community forests and small-scale forests—the expression domestic forest has recently been proposed. Domestic forest is a term aimed at capturing the diversity of forests transformed and managed by rural communities and a way to introduce a new scientific domain that recognises that production and conservation can be reconciled and that local communities can be effective managers. This paper argues in the context of the central Western Ghats of south India that while the domestic forest concept is a useful umbrella term to capture the diversity of forests used by rural people, these domestic forests are often not autonomous local forests but sites of contestation between local actors and the state forest bureaucracy. Hence, a paradigm shift within the forest bureaucracy will only occur if the scientific forestry community questions its own normative views on forest management and sees forest policy as a means to recognise local claims and support existing practices of forest dependent communities.     

Potential spread of the pine processionary moth in France: preliminary results from a simulation model and future challenges

Context

Some forest insect pests are currently extending their range as a consequence of climate warming. However, in most cases, the evidence is mainly based on correlations and the underlying mechanism is not clearly known.

Aims

One of the most severe pests of pine forests in Europe, the pine processionary moth, Thaumetopoea pityocampa, is currently expanding its distribution as a result of climate warming and does not occupy entirely its potential habitat. A model describing its spread was developed to simulate its potential range in France under various climate change scenarios.

Methods

The spread model was divided into several sub-models to describe the growth, survival and dispersal of the species. The model was validated on the observed change of species distribution, its sensitivity was tested, and spread scenarios were simulated for the future.

Results

The model shows that climate warming initiated the species range expansion in France since the early 1990s. The spread is now limited by dispersal capability, but human-mediated dispersal could accelerate the range expansion.

Conclusion

Species range expansion is an indicator of climate change. However, time lags can appear due to limited dispersal capabilities, and human-mediated dispersal could create satellite colonies and artificially accelerate the spread.     

Yield and grain protein concentration in bread wheat: how to use the negative relationship between the two characters to identify favourable genotypes?

A study of the relationship between grain yield (GY) and grain protein concentration (GPC) in bread wheat was carried out on a 11-year series of trials conducted by the Groupement d’Etude des Variétés Et Semences (GEVES) for the registration of new cultivars on the French National List. Values for GY and GPC came from 458 individual trials, grouped together in 21 series of bi-annual and multi-site data. The correlations between the two characters, calculated environment by environment, appeared highly variable due to high “genotype × environment” interactions for GY and GPC. The use of mean values, calculated on the 21 series of GEVES trials, enabled a better assessment of the relationship between the two characters, and an algorithm was proposed to avoid bias due to potential outliers. Using the well-assessed relationship obtained, grain protein deviations (GPDs) were defined as the standardized residuals of the regression of GPC on GY. These deviations appeared to have a partly genetic basis, as the lines with high deviations were about the same in the two independent datasets constituted by the two consecutive years of GEVES experiments. Some lines used as standards in GEVES trials obtained significant GPD for different series of bi-annual and multi-site trials, confirming the genetic origin of high-GPD. Simulations made to determine the minimum experimental design, showed that at least five sites per year for two consecutive years, were necessary to have a good assessment of the GY–GPC relationship, and hence reliable estimates of GPD.     

Antioxidant profiling of native Andean potato tubers (Solanum tuberosum L.) reveals cultivars with high levels of beta-carotene, alpha-tocopherol, chlorogenic acid, and petanin

The antioxidant profile of 23 native Andean potato cultivars has been investigated from a human nutrition perspective. The main carotenoid and tocopherol compounds were studied using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) and a fluorescence detector, respectively, whereas polyphenols (including anthocyanins in colored tubers) were identified by means of both HPLC-mass spectrometry and HPLC-DAD. Antioxidant profiling revealed significant genotypic variations as well as cultivars of particular interest from a nutritional point of view. Concentrations of the health-promoting carotenoids, lutein and zeaxanthin, ranged from 1.12 to 17.69 microg g(-1) of dry weight (DW) and from 0 to 17.7 microg g(-1) of DW, with cultivars 704353 and 702472 showing the highest levels in lutein and zeaxanthin, respectively. Whereas beta-carotene is rarely reported in potato tubers, remarkable levels of this dietary provitamin A carotenoid were detected in 16 native varieties, ranging from 0.42 to 2.19 microg g(-1) of DW. The amounts of alpha-tocopherol found in Andean potato tubers, extending from 2.73 to 20.80 microg g(-1) of DW, were clearly above the quantities generally reported for commercial varieties. Chlorogenic acid and its isomers dominated the polyphenolic profile of each cultivar. Dark purple-fleshed tubers from the cultivar 704429 contained exceptionally high levels of total anthocyanins (16.33 mg g(-1) of DW). The main anthocyanin was identified as petanin (petunidin-3-p-coumaroyl-rutinoside-5-glucoside). The results suggest that Andean potato cultivars should be exploited in screening and breeding programs for the development of potato varieties with enhanced health and nutritional benefits.     

Andean potato cultivars (Solanum tuberosum L.) as a source of antioxidant and mineral micronutrients

Potato tubers were evaluated as a source of antioxidants and minerals for the human diet. A genetically diverse sample of Solanum tuberosum L. cultivars native to the Andes of South America was obtained from a collection of nearly 1000 genotypes using microsatellite markers. This size-manageable collection of 74 landraces, representing at best the genetic diversity among potato germplasm, was analyzed for iron, zinc, calcium, total phenolic, total carotenoid, and total vitamin C contents. The hydrophilic antioxidant capacity of each genotype was also measured using the oxygen radical absorbance capacity (ORAC) assay. The iron content ranged from 29.87 to 157.96 microg g-1 of dry weight (DW), the zinc content from 12.6 to 28.83 microg g-1 of DW, and the calcium content from 271.09 to 1092.93 microg g-1 of DW. Total phenolic content varied between 1.12 and 12.37 mg of gallic acid equiv g-1 of DW, total carotenoid content between 2.83 and 36.21 microg g-1 of DW, and total vitamin C content between 217.70 and 689.47 microg g-1 of DW. The range of hydrophilic ORAC values was 28.25-250.67 micromol of Trolox equiv g-1 of DW. The hydrophilic antioxidant capacity and the total phenolic content were highly and positively correlated (r = 0.91). A strong relationship between iron and calcium contents was also found (r = 0.67). Principal component analysis on the studied nutritional contents of the core collection revealed that most potato genotypes were balanced in terms of antioxidant and mineral contents, but some of them could be distinguished by their high level in distinct micronutrients. Correlations between the micronutrient contents observed in the sample and the genetic distances assessed by microsatellites were weakly significant. However, this study demonstrated the wide variability of health-promoting micronutrient levels within the native potato germplasm as well as the significant contribution that distinct potato tubers may impart to the intake in dietary antioxidants, zinc, and iron.