Spatial distribution of Aphanomyces euteiches inoculum in a naturally infested pea field

The main objective of the study was to describe the horizontal and vertical distribution of Aphanomyces root rot in a naturally infested pea field. Measurements of inoculum potential clearly indicated a horizontal distribution of inoculum among several foci in the field, these foci differing in size and disease intensity. A highly significant relationship was observed between disease severity on plants during the cropping season and soil inoculum potential. In terms of the vertical distribution of inoculum in the soil, detection was maximal at a depth of 10 to 40 cm, but inoculum was detected down to a depth of 60 cm. Generally, inoculum potential was lowest for the layers at depths of 0 to 10 and 50 to 60 cm. Inoculum distribution and the value of the methodologies used are discussed in terms of possible use for epidemiology and disease forecasting.     

Xylella fastidiosa subspecies and sequence types detected in Philaenus spumarius and in infected plants in France share the same locations

In Europe, the meadow spittlebug Philaenus spumarius is the main known vector of the quarantine bacterium Xylella fastidiosa. So far detection and identification of X. fastidiosa has more often been performed from plant matrices than insects, mainly using a real-time PCR and multilocus sequence typing (MLST) approach. Detection of X. fastidiosa in its insect vectors would enhance knowledge of the epidemiologic situation in France, specifically in the already infected Corsica and Provence-Alpes-Côte d’Azur (PACA) regions. The aim of this study was to validate a methodological approach to detect X. fastidiosa in P. spumarius, analysed individually or in groups of 10, using real-time PCR and MLST, and to apply the approach to more than 4,000 individuals collected between 2015 and 2019 from infected areas. The corresponding results expanded our knowledge of the epidemiology of X. fastidiosa in France: (a) X. fastidiosa subsp. multiplex including the sequence types ST6 and ST7 were identified in the insect vector; (b) the rate of positive insects per infected area was as high as 33.3% in Corsica or 50% in the PACA region; (c) positive adults were found during winter; and (d) the bacterial load in P. spumarius (droplet digital PCR) usually ranged from 10³ to 10⁴ cells per insect, but could be as high as 10⁵ or 10⁶ cells per insect for some individuals (13%). The subspecies and sequence types detected in P. spumarius corresponded to the situation officially reported for plants in the same areas.     

Efficiency of working dogs undergoing a new Human Familiarization and Training Program

The study of human-dog interaction has increased over the past several years. It has been demonstrated that dogs can use a number of human social cues to successfully accomplish a task, and that they do so better than apes. Many authors agree that these abilities are a result of 10,000 years of domestication by humans. Domestication may have genetically predisposed dogs to accurately recognize human communication signals. However, only a few authors have studied the performance of working dogs, implying recognition of human communication signals. Haverbeke et al. (2008) found that military working dogs do not always perform as they are expected to. To investigate this finding, we studied the performance of obedience and protection work exercises between 2 groups of dog-handler teams: a control group (CG), trained using the current training method used by the Belgian Defense, and an experimental group (EG) that underwent a new human familiarization and training program. During obedience and protection work exercises, EG teams obtained better results than CG teams and EG dogs exhibited a higher body posture than CG dogs. The results suggest that even if dogs are genetically predisposed toward the recognition of human communication signals, this aptitude alone does not explain the dogs' performance and their interactions with humans in this study. Regular training combined with positive dog-handler interaction is also required to increase the dog-handler (DH) team's performances.     

Increased productivity through integrated soil fertility management in cassava–legume intercropping systems in the highlands of Sud-Kivu,DR Congo

Smallholder farmers in sub-Saharan Africa are confronted by low productivity and limited investment capacity in nutrient inputs. Integrated soil fertility management (ISFM) aims at increased productivity through the combined use of improved germplasm, judicious fertilizer application and organic matter management, adapted to the local farming conditions. We hypothesize that the application of these different ISFM components can result in significant increases in productivity and economic benefits of cassava–legume intercropping systems. Participatory demonstration trials were conducted in the highlands of Sud-Kivu, DR Congo with 12 farmer groups during 3 seasons. Treatments included the farmers’ common practice (local common bean and cassava varieties, seed broadcast and manure addition) and sequentially added ISFM components: improved bean and cassava germplasm, modified crop arrangements, compound NPK fertilizer application and alternative legume species (groundnut or soybean). The use of improved germplasm did not result in yield increases without simultaneous implementation of other ISFM components. Modifying the crop arrangement by planting cassava at 2 m between rows and 0.5 m within the row, intercropped with four legume lines, increased bean yields during the first season and permits a second bean intercrop, which can increase total legume production by up to 1 t ha⁻¹ and result in an additional revenue of almost 1000 USD ha⁻¹. Crop arrangement or a second legume intercrop did not affect cassava storage root yields. Fertilizer application increased both legume and cassava yield, and net revenue by 400–700 USD ha⁻¹ with a marginal rate of return of 1.6–2.7. Replacing the common bean intercrop by groundnut increased net revenue by 200–400 USD ha⁻¹ partly because of the higher market value of the grains, but mostly due to a positive effect on cassava storage root yield. Soybean affected cassava yields negatively because of its high biomass production and long maturity period; modifications are needed to integrate a soybean intercrop into the system. The findings demonstrate the large potential of ISFM to increase productivity in cassava–legume systems in the Central-African highlands. Benefits were, however, not observed in all study sites. In poor soils, productivity increases were variable or absent, and soil amendments are required. A better understanding of the conditions under which positive effects occur can enable better targeting and local adaptation of the technologies.     

Morphological and molecular diversity within Algerian cowpea (<Emphasis Type="Italic">Vigna unguiculata</Emphasis> (L.) Walp.) landraces

Twenty landraces of cowpea (Vigna unguiculata (L.) Walp.) scattered throughout Algeria were compared through morphological and genetic characterization. At the morphological level, for qualitative characters there was no intra-landrace variation and for quantitative characters the variations were low except for landrace NAG2 Three different cultigroups were located in Algeria: Biflora that was dominant in the Sahara, Melanophtalmus in the North and Unguiculata including one landrace in Kabylia and two in Sahara. The AMOVA analysis indicated that the genetic variation was lower within than among agro-ecological regions. A Mantel test, revealed a correlation between the qualitative morphological data and the geographical data (R = 0.28; P < 0.01), indicating that the degree of morphological change among landraces was roughly proportional to the geographical distances separating them. Genetic diversity was analyzed by using 11 random amplified polymorphic DNA (RAPD) and 12 inter-simple sequence repeat (ISSR) markers. No intra-landrace variability was found. The eleven RAPD primers yielded 77 bands, of which 45 (58.44%) were polymorphic; the genetic similarity ranged from 66.0 to 96.7%. The twelve ISSR primers provided a total of 104 bands, of which 65 (62.5%) were polymorphic; the genetic similarity ranged from 62.8 to 97.8%. cluster analysis showed a good match between genetic background and geographical distribution, which was confirmed by the results of the Mantel test. In particular, geographical data and genetic data were found to be correlated: (R = 0.33; P < 0.01) for RAPD, (R = 0.37; P < 0.01) for ISSR, and (R = 0.33; P < 0.01) for a combined RAPD-ISSR dataset. Moreover, despite the absence of significant correlation between morphological and RAPD data (R = 0.14; P = 0.14), significant correlations between morphological data and both ISSR (R = 0.27, P < 0.05) and a combined RAPD-ISSR dataset (R = 0.22, P < 0.05) were noted. ISSR markers were better linked to morphological variation than were RAPD markers. However, despite this, genetic distances among these landraces were found to be essentially the same no matter which markers were used.     

Influence of the Iron-Reducing Bacteria on the Release of Heavy Metals in Anaerobic River Sediment

The impact of autochthonous anaerobic bacteria on the release of metals in river sediment was studied. The sediments were characterized and bacterial activity was monitored in a batch reactor, where the sediments were incubated with a synthetic substrate solution containing glucose as carbon source. The results showed that metal release was correlated to the bacterial growth (carbon mineralization). In particular, a relationship between iron reduction and metal release was observed indicating that iron-reducing bacteria had a strong influence. By reductive dissolution of iron oxides, bacteria also released their associated toxic elements into the liquid phase. While organic analysis showed acetate and butyrate production leading to a decrease in pH and indicating a Clostridium fermentative bacteria activity, the results did not indicate any direct role of organic acids in the dissolution of iron and their associated metals.     

(E)-Methylisoeugenol and elemicin: antibacterial components of Daucus carota L. essential oil against Campylobacter jejuni

The essential oil of wild Daucus carota L. obtained from aerial parts at the end of the flowering stage (DCEO) was reported as antimicrobial against the human enteropathogen Campylobacter jejuni. The aim of the present study was to extend this analysis to other Campylobacter species and to identify the active compounds of the essential oil, subjected to GC, GC-MS, and (13)C NMR analysis. A minimum inhibitory concentration assay was used to quantify the antimicrobial activity of DCEO and the major components, isolated on column chromatography. Growth of all the C. jejuni, Campylobacter coli, and Campylobacter lari strains tested, including one multidrug resistant C. jejuni, was inhibited to the same extent by DCEO. Molecules that were responsible for the antibacterial activity were identified as (E)-methylisoeugenol and elemicin. Moreover, the use of structural analogues of these compounds allowed us to identify important features that may account for the activity.     

Relationship between haptoglobin, serum amyloid A, and clinical status in a survey of dairy herds during a 6-month period

BACKGROUND: Haptoglobin and serum amyloid A are major acute phase proteins in cattle. Dairy cattle often develop pathologic conditions in the peripartum period; acute phase proteins may be useful in their diagnosis. OBJECTIVES: The purpose of this study was to compare the accuracy of serum haptoglobin (Hp) and serum amyloid A (SAA) concentrations with clinical health status for diagnosing disease during the peripartum period in dairy cattle. METHODS: Dairy cows from 4 herds were evaluated every 15 days over a 6-month period. Health status was determined by thorough clinical examination. Haptoglobin and SAA concentrations were measured in serum using validated methods and the results were classified as positive or negative based on defined cutoff points. Disease prevalence, sensitivity, and specificity were compared using clinical examination as the gold standard. RESULTS: A total of 1896 samples from 158 cows were analyzed. Significant increases in mean Hp and SAA concentrations were observed in the week following parturition in both primiparous and multiparous cows, although high interindividual variability was observed. Both Hp and SAA had low sensitivity but higher specificity in determining disease status compared with clinical examination. Increased concentrations of Hp and SAA were found in <10% of samples from clinically healthy cows, except in the week after parturition. CONCLUSIONS: Haptoglobin and serum amyloid A should be used with caution as markers of inflammation in the week after calving. Poor sensitivity in other postpartum periods could be related to the higher incidence of chronic (vs acute) inflammation. Haptoglobin may be appropriate for routine screening, but further work needs to be done to assess its value as an indicator of herd health.     

Alterations in 5-HT1B receptor function by p11 in depression-like states

The pathophysiology of depression remains enigmatic, although abnormalities in serotonin signaling have been implicated. We have found that the serotonin 1B receptor [5-hydroxytryptamine (5-HT1B) receptor] interacts with p11. p11 increases localization of 5-HT1B receptors at the cell surface. p11 is increased in rodent brains by antidepressants or electroconvulsive therapy, but decreased in an animal model of depression and in brain tissue from depressed patients. Overexpression of p11 increases 5-HT1B receptor function in cells and recapitulates certain behaviors seen after antidepressant treatment in mice. p11 knockout mice exhibit a depression-like phenotype and have reduced responsiveness to 5-HT1B receptor agonists and reduced behavioral reactions to an antidepressant.     

Dynamic MRI and thermal simulation to interpret deformation and water transfer in meat during heating

Understanding and controlling structural and physical changes in meat during cooking is of prime importance. Nuclear magnetic resonance imaging (MRI) is a noninvasive, nondestructive tool that can be used to characterize certain properties and structures both locally and dynamically. Here we show the possibilities offered by MRI for the in situ dynamic imaging of the connective network during the cooking of meat to monitor deformations between 20 and 75 °C. A novel device was used to heat the sample in an MR imager. An MRI sequence was developed to contrast the connective tissue and the muscle fibers during heating. The temperature distribution in the sample was numerically simulated to link structural modifications and water transfer to temperature values. The contraction of myofibrillar and collagen networks was observed at 42 °C, and water began to migrate toward the interfascicular space at 40 °C. These observations are consistent with literature results obtained using destructive and/or nonlocalized methods. This new approach allows the simultaneous monitoring of local deformation and water transfer, changes in muscle structure and thermal history.