Circular Business Model for Digital Health Solutions: Protocol for a Scoping Review.

BACKGROUND: The circular economy reshapes the linear "take, make, and dispose" approach and evolves around minimizing waste and recapturing resources in a closed-loop system. The health sector accounts for 4.6% of global greenhouse gas emissions and has, over the decades, been built to rely on single-use devices and deal with high volumes of medical waste. With the increase in the adoption of digital health solutions in the health care industry, leading the industry into a new paradigm of how we provide health care, a focus must be put on the amount of waste that will follow. Digital health solutions will shape health care through the use of technology and lead to improved patient care, but they will also make medical waste more complex to deal with due to the e-waste component. Therefore, a transformation of the health care industry to a circular economy is a crucial cornerstone in decreasing the impact on the environment. OBJECTIVE: This study aims to address the lack of direction in the current literature on circular business models. It will consider micro, meso, and macro factors that would impact the operational validity of circular models using the digital health solutions ePaper label (medical packaging), smart wearable sensor (health monitoring devices), smart pill box (medication management), and endo-cutter (surgical equipment) as examples. METHODS: The study will systematically perform a scoping review through a database and snowball search. We will analyze and classify the studies from a predetermined set of categories and then summarize them into an evidence map. Based on the review, the study will develop a 2D framework for businesses to follow or for future research to take a standpoint from. RESULTS: Preliminarily, the review has analyzed 26 studies in total. The results are close to equally distributed among the micro (8/26, 31%), meso (10/26, 38%), and macro (8/26, 31%) levels. Circular economy studies emphasize several circular practices such as recycling (17/26, 65%), reusing (18/26, 69%), reducing (15/26, 58%), and remanufacturing (8/26, 31%). The value proposition in the examined business model is mostly dominated by stand-alone products (18/26, 69%) compared to product as a service (7/26, 27%), involving stakeholders such as health care professionals or hospitals (20/26, 77%), manufacturers (11/26, 42%), and consumers (9/26, 35%). All studies encompass societal (12/26, 46%), economic (23/26, 88%), and environmental (24/26, 92%) viewpoints. CONCLUSIONS: The study argues that each digital health solution would have to be accessed individually to find the optimal business model to follow. This is due to their differing life cycles and complexity. The manufacturer will need a layered value proposition, implementing several business models dependent on their respective product portfolios. The need to incorporate several business models implies an ecosystem perspective that is relevant to consider. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/47874.

Shifts in dietary patterns and risk of type-2 diabetes in a Caribbean adult population: ways to address diabetes burden.

PURPOSE: As the French West Indies are facing an ongoing nutrition transition with increasing type-2 diabetes mellitus (T2DM) prevalence, our study aimed to evaluate the effect of potential shifts in dietary patterns on T2DM risk in French West Indian adults according to several scenarios. METHODS: We used a cross-sectional multistage sampling survey on dietary intake conducted in 2013 on a representative sample of Guadeloupeans and Martinicans adults (n = 1063). From previously identified current dietary patterns, we used PRIME-Diabetes, a comparative risk assessment model, to estimate the effect of potential shifts from the "transitioning" pattern to the "convenient," the "prudent," and the "traditional" ones on T2DM risks. RESULTS: Potential shift in dietary intakes from the "transitioning" pattern to the "traditional" one reduced the T2DM risk in women (- 16% [- 22; - 10]) and in men - 14% [- 21; - 7]), as the shift in dietary intakes toward the "prudent" pattern (- 23% [- 29; - 17] and - 19% - 23; - 14], respectively). These risk reductions were mostly driven by increased whole grains, fruits, green leafy vegetable intakes, and decreases in potatoes, red meats, processed meats, and sugar-sweetened beverages. The shift in dietary intakes toward the "convenient" pattern did not affect the T2DM risks. CONCLUSION: To curb the increase in T2DM prevalence and reduce this burden, one public health action could be to target transitioning adults and help them to shift towards a diet associated with a reduced risk of T2DM as a prudent or a traditional diet.

How Different Are Industrial, Artisanal and Homemade Soft Breads?

Soft bread has a significant relevance in modern diets, and its nutritional impact on human health can be substantial. Within this product category, there is an extensive range of ingredients, formulations, and processing methods, which all contribute to the vast diversity found in the final products. This work compared the impact of three different processing methods (industrial, artisanal, and homemade preparation) on the technological (formulation and processing, as they are interconnected in real-life conditions), nutritional, and physicochemical properties of soft bread. In total, 24 types of soft bread were analyzed: 10 industrial, 6 artisanal, and 8 homemade. Although production diagrams were similar among the three methods, industrial recipes contained on average more ingredients and more additives. Industrial bread was lower in saturated fat compared to the other two groups, but contained more sugar than homemade bread. The physical properties of all loaves were comparable, with the exception of higher crumb elasticity in industrial bread compared to homemade. An analysis of volatile molecules revealed more lipid oxidation markers in industrial bread, more fermentation markers in artisanal bread, and fewer markers of Maillard reactions in homemade bread. Chemical reactions during processing seem to be the principal criterion making possible to discriminate the different processing methods. These results offer a quantitative assessment of the differences within a single product category, reflecting the real-world choices for consumers.

A Probabilistic Structural Equation Model to Evaluate Links between Gut Microbiota and Body Weights of Chicken Fed or Not Fed Insect Larvae.

Feeding chicken with black soldier fly larvae (BSF) may influence their rates of growth via effects on the composition of their gut microbiota. To verify this hypothesis, we aim to evaluate a probabilistic structural equation model because it can unravel the complex web of relationships that exist between the bacteria involved in digestion and evaluate whether these influence bird growth. We followed 90 chickens fed diets supplemented with 0%, 5% or 10% BSF and measured the strength of the relationship between their weight and the relative abundance of bacteria (OTU) present in their cecum or cloaca at 16, 28, 39, 67 or 73 days of age, while adjusting for potential confounding effects of their age and sex. Results showed that OTUs (62 genera) could be combined into ten latent constructs with distinctive metabolic attributes. Links were discovered between these constructs that suggest nutritional relationships. Age directly influenced weights and microbiotal composition, and three constructs indirectly influenced weights via their dependencies on age. The proposed methodology was able to simplify dependencies among OTUs into knowledgeable constructs and to highlight links potentially important to understand the role of insect feed and of microbiota in chicken growth.

Impact of intra-category food substitutions on the risk of type 2 diabetes: a modelling study on the pizza category.

Advice on replacing unhealthy foods with healthier alternatives within the same food category may be more acceptable and might ease the transition towards a healthy diet. Here, we studied the potential impact of substitutions within the pizza category on the risk of type 2 diabetes (T2D). The study sample consisted of 2510 adults from the INCA2 French national survey. Based on their nutritional characteristics, the 353 pizzas marketed in France were grouped into 100 clusters that were used to run various scenarios of pizza substitutions, which were either isoenergetic (IE) or non-isoenergetic (NIE). We then used a model structurally similar to the Preventable Risk Integrated ModEl to assess the expected rate of change in risk of T2D. Pizzas characterised by a low energy, high vegetable content and whole grain dough were associated with a greater reduction in the risk of T2D. The rates of change in risk of T2D were markedly stronger in men and for NIE substitutions. When the rates of change were estimated in the subsample of pizza consumers, replacing the observed pizzas with the best pizza resulted in a T2D risk reduction of -6·7 % (-8·4 %; -4·9 %, IE) and -8·9 % (-11·2 %; -6·3 %, NIE), assuming that this is their usual diets. The greatest risk reduction induced by an IE substitution of the observed pizza with a mixed dish was similar to that observed with the best pizzas. Overall, this modelling study suggests that healthy swaps within a category can effectively supplement broader dietary changes towards a healthier diet.

Public health potential of guidelines-based dietary scores for non-communicable diseases mortality prevention: simulation study using the Preventable Risk Integrated ModEl (PRIME) model.

OBJECTIVE: Dietary indexes measure the adherence of individuals to a set of nutritional recommendations. However, the health gains associated with adherence to various dietary indexes may vary. Our objective was to compare the magnitude of estimated avoided deaths by chronic diseases obtained by improving diet quality in the French population, measured by a variety of dietary indexes. DESIGN: Simulation study based on observational data. SETTING: Weighted data from a French population-based cohort study. PARTICIPANTS: In participants from the NutriNet-Santé cohort, we computed dietary scores reflecting the adherence to various recommendations (Medi-Lite, Healthy Diet Indicator (HDI), Programme National Nutrition Santé/National Nutrition and Health Program - Guidelines Score, Diet Quality Index (DQI), Alternative Healthy Eating Index (AHEI) and the modified Food Standards Agency nutrient profiling system dietary index (FSAm-NPS DI)). Quintiles of the food groups' consumption and dietary intakes were used as input in a simulation model (Preventable Risk Integrated ModEl (PRIME)), yielding the number of delayed or avoided deaths in nutrition-related non-communicable diseases, comparing between very high or very low nutritional quality of the diet and medium nutritional quality. RESULTS: A modification of dietary intakes from medium quality to very low quality (i.e. from the middle quintile to the quintile with the lowest nutritional quality) was associated with an increased number of deaths ranging from 3485 (95 % uncertainty interval (CI) 4002, 2987) for HDI and 3379 (95 % CI 3881, 2894) for FSAm-NPS DI to 838 (95 % CI 1163, 523) for Medi-Lite. Conversely, a modification of dietary intakes from medium quality to very high quality was associated with a decrease in the number of deaths ranging from 1995 (95 % CI 1676, 2299) for Probability of Adequate Nutrient intake diet, 1986 (95 % CI 1565, 2361) for DQI-International, 1931 (95 % CI 1499, 2316) for FSAm-NPS DI and 858 (95 % CI 499, 1205) for HDI. CONCLUSIONS: Our results provide some insights as the potential impact of following various dietary guidelines to reduce mortality from nutrition-related diseases.

Valuing breeders' preferences in the conservation of the Koundoum sheep in Niger by multi-attribute analysis.

This study characterises farmer's preferences for breeding rams and tackles their willingness to contribute to the Koundoum sheep conservation programme through their quantified appreciation of the main phenotypic features of the sheep breed in the region. The Koundoum is the main wool sheep of Niger and shows a remarkable adaptation to the environment of the Niger River valley. In Tillabéri region, i.e. the Koundoum sheep's area of origin, the proportional piling tool is first used in 11 focus group discussions of breeders to determine the main selection criteria of breeding rams. The multi-attribute analysis method is then applied with 168 sheep owners. The econometric estimation of the utility function of breeders is conducted with a conditional logit model and the marginal willingness to pay is calculated. The results reveal a strong rejection by the breeders of characteristics like wool and black-coloured coat and thus shows the poor acceptability of an in situ conservation programme. Few breeders with a particular concern for the breed's conservation for cultural motives may nevertheless join such a conservation programme that should mainly be based on ex situ strategies.

Phenotypic parameters affecting reproduction and production performances of dairy cattle in peri-urban of Bamako, Mali.

AIM: The present study was conducted to evaluate the reproduction and production performances of crossbred and local dairy cattle in peri-urban of Bamako, the capital of Mali. MATERIALS AND METHODS: A total of 17 randomly selected households with 450 dairy cattle from four peri-urban of Bamako were individually interviewed, given register format and divided into four focus group discussions. The participants were dairy farmers and they were asked to know the phenotype that seems to them the more interesting for the reproduction and production performances of their dairy cattle. RESULTS: The calving interval (CI) obtained exceeded 433 days in all phenotypic types with average milk yields of 5.13±1.84 kg/day, 4.76±2.41, and 3.05±1.32 kg/day, respectively, for the Holstein crossbred, Montbeliard crossbred, and the local breeds (Zebu Peul and/or Zebu Maure). Crossbred was more productive than local breeds with significant (p<0.05) differences for lactation length, CI and total production and not significant on parity. The results also showed the advantages of the crossbred cows in terms of CI (460±80 days) compared to local zebus breeds (433±115 days) to keep the time of milking as long as possible. However, the Zebu Azawak breed whose cradle is located in Northern Mali, managed under extensive peri-urban rearing conditions, has less favorable production parameters than those of other local cattle breeds in milk production (636±43.3 kg vs. 681±41.1 kg). CONCLUSION: The present study revealed that crossbred dairy cattle performed better in terms of CI, lactation length, and production compared to the local breeds. The study also showed that the local Azawak breed numerically performed less compared to the other local breeds evaluated in this study, namely, Peul and Maure.

Effects of stinging nettle (Urtica dioica) powder on laying performance, egg quality, and serum biochemical parameters of Japanese quails.

The aim of this experiment was to evaluate the effects of dietary supplementation of stinging nettle powder (SNP) on laying performance, egg quality, and some selected serum biochemical parameters of quails. One hundred and forty-four 10-wk-old Japanese quails (initial body weight = 199 ± 18 g) were divided into 3 dietary treatment groups (basic diet without SNP [SNP0], SNP0 with 3% SNP [SNP3], SNP0 with 6% SNP [SNP6]) with 4 replicates of 12 quails for a rearing period of 12 wk. At 22 wk of age, the final body weights of the SNP3 and SNP6 groups were significantly (P = 0.001) reduced compared to that of the SNP0 group. Daily feed intake was not statistically different among the groups. The mean number of eggs laid ranged from 65 to 69 with laying rates from 76.8% to 82.1%. The percentage of cracked eggs was not significantly different among the groups and ranged from 1.6% to 1.9%. The egg weight was similar and the feed conversion ratio was closer among the groups. The egg yolk cholesterol, serum cholesterol and serum triglyceride levels in the SNP6 group were significantly reduced (P < 0.001) compared to those of the SNP0 group. Serum Ca, P and Mg were not significantly influenced by the supplementation. In conclusion, the results demonstrated that the supplementation of SNP to the quail diet at the level of 6% reduced quail egg yolk cholesterol, serum total cholesterol and serum triglyceride levels and did not negatively influence quail performance.

Accounting for consumers' preferences in the analysis of dietary recommendations.

BACKGROUND/OBJECTIVES: The goal of this article is to present and demonstrate the applicability of an original method to assess the economic and health impacts of compliance with food-based recommendations. The method takes account of consumers' preferences and the associated adoption cost in the assessment of various recommendations. SUBJECTS/METHODS: We combine an economic model of diet choice with an epidemiological model to compute the health impacts of dietary changes. To demonstrate the use of the method, we analyse the impacts of a 5% variation in the consumption of seven food groups taken separately: a 5% increase in consumption of fruits and vegetables (F&V) and milk products; and a 5% decrease in consumption of red meat, all meats, salty/sweet products, ready meals and butter/cream/cheese. RESULTS: A recommendation, when adopted by consumers, generates important changes in the whole diet due to substitutions and complementarities among foods. All simulated recommendations have a positive impact on health. The F&V recommendation has the largest impact on the number of DALYs averted, but the highest adoption cost for consumers, especially for low-income consumers. Alone, the change in energy intake explains from 71% to 98% of the DALYs averted induced by a recommendation. CONCLUSIONS: Small increases in recommended foods have the potential of generating relatively significant health gains. Preference-driven substitutions among foods have a major effect on simulated health outcomes and should be included in the assessment of dietary recommendations, together with the adoption cost borne by consumers.

Performances of local poultry breed fed black soldier fly larvae reared on horse manure.

In poultry, feed based on maggots, like larvae of black soldier fly (Hermetia illucens) is an attractive option to substitute current ingredients which are expensive and often in direct or indirect competition with human food. Little information is currently available on the utility of these larvae in poultry feed, so goals of this study were to determine whether larvae could be reared on horse manure under traditional farming conditions and to evaluate the growth performances of a local poultry fed these larvae and the fatty acids profiles of their meat. After freezing and thawing, larvae were introduced in the feed of Ardennaise chickens between 30 and 80 days of age. Birds in the control group received a commercial standard feed, while those in the treatment group received the same commercial feed in which 8% was substituted with whole fresh larvae corresponding to 2% on a dry matter basis. Means ± standard errors of larval length and weight were 20.67 ± 2.21 mm and 0.14 ± 0.02 g, respectively. Mean larval percentages of dry matter and of substances extractable in diethyl ether were 24.6% and 23.1%, respectively. Larval fatty acids profiles were predominantly composed of lauric acid (28.1%) and palmitic acid (22.0%). Least squares means of weekly weights of chicken, adjusted for the effects of sex, replication and initial weights, were significantly higher (P < 0.05) by 77.03 ± 53.37 g in larvae-fed than in control chickens. All other measurements were not statistically different between larvae-fed and control chicken, including fatty acid profiles, protein content and ω6/ω3 ratio.

Trypanosomiasis challenge estimation using the diminazene aceturate (Berenil) index in Zebu in Gabon.

A longitudinal study was conducted within a cattle ranch in Gabon to determine the diminazene aceturate (Berenil) index (DAI) in a group of Zebu, raised under low tsetse density; this measure providing an assessment of trypanosomiasis risk. The objective was to evaluate the trypanosomiasis pressure thus informing trypanosomiasis control methods and cattle management. Twenty female adult Zebu were monitored for 24 weeks during the dry season. Blood samples were collected on a weekly basis and subjected to parasitological and haematological analysis (n = 480), using the buffy-coat method and the packed cell volume value (PCV), respectively, infected animals were treated with a single intramuscular injection of diminazene aceturate (8 mg/kg). Twenty-nine single infectious events were recorded and a DAI of 1.45 was calculated. Two trypanosome species were identified: Trypanosoma congolense (96.2%) and Trypanosoma vivax (3.8%). The mean PCV value of the infected animals was lower (26.6) compared to non-infected animals (32.0). This study shows that DAI may be a useful tool to assess trypanosomiasis. However, this is a time-consuming method that may be improved by using randomly selected sentinel animals to adapt the chemoprophylactic schemes, hence decreasing the costs and the drug resistance risk.

Beyond Wishful Thinking: Integrating Consumer Preferences in the Assessment of Dietary Recommendations.

Convenience, taste, and prices are the main determinants of food choices. Complying with dietary recommendations therefore imposes a "taste cost" on consumers, potentially hindering adoption of those recommendations. The study presents and applies a new methodology, based on economic theory, to quantify this taste cost and assess the health and welfare effects of different dietary recommendations. Then, by comparison of those effects, we identify socially desirable recommendations that are most compatible with consumer preferences (i.e., that best balance health benefits against"taste cost") and should be prioritized for promotion. The methodology proceeds in three-steps: first, an economic-behavioral model simulates how whole diets would change if consumers complied with dietary recommendations; second, an epidemiological model estimates the number of deaths avoided (DA) due to the dietary change; third, an efficiency analysis weighs the health benefits against the taste and policy costs of each recommendation. The empirical model is calibrated using French data. We find that recommendations to reduce consumption of red meat and soft-drinks, or raise consumption of milk products and fish/seafood impose relatively moderate taste costs. By comparison, recommendations related to F&V consumption and, to a lesser extent, butter/cream/cheese, snacks, and all meats impose larger taste costs on consumers. The F&V recommendation is the costliest for consumers to comply with, but it also reduces diet-related mortality the most, so that a large budget could be allocated to promoting F&V consumption while keeping this policy cost-beneficial. We conclude that promotion of most dietary recommendations improves social welfare. Our framework complements the programming models available in nutrition and public health: those models are best used to identify dietary targets, following which our framework identifies cost-beneficial ways of moving towards those targets.

Economic assessment of nutritional recommendations.

The effect of consumers' compliance with nutritional recommendations is uncertain because of potentially complex substitutions. To lift this uncertainty, we adapt a model of consumer behaviour under rationing to the case of linear nutritional constraints. Dietary adjustments are derived from information on consumer preferences, consumption levels, and nutritional contents of foods. A calibration exercise simulates, for different income groups, how the French diet would respond to various nutrition recommendations, and those behavioural adjustments are translated into health outcomes through the DIETRON epidemiological model. This allows for the ex-ante comparison of the efficiency, equity and health effects of ten nutritional recommendations. Although most recommendations impose significant taste costs on consumers, they are highly cost-effective, with the recommendations targeting salt, saturated fat, and fruits and vegetables (F&V) ranking highest in terms of efficiency. Most recommendations are also economically progressive, with the exception of that targeting F&V.

Characterisation of camel breeding practices in the Ansongo Region, Mali.

Despite its importance in Mali's economy, camel breeding in the country remains poorly documented, impeding effective policy-making in this regard. This study consisted in a 3-month survey and aimed at characterising camel breeding systems in Ansongo, in the region of Gao, Mali. It highlights the diversity of strategies adopted by breeders and their evolutions. Supplementary feeding and veterinary care were seldom practised. In zones close to the Niger River, cattle were substituted to camels. Transhumance routes also are modified but mobility keeps its vital role in the breeding system. Important differences within the study region in the classification of camel breeds have been reported that will influence the implementation of a collective action for animal genetic improvement. The improvement goals should take the actual management, including mobility and the mixed nature of the herds into account.

Proteomic investigation of aphid honeydew reveals an unexpected diversity of proteins.

Aphids feed on the phloem sap of plants, and are the most common honeydew-producing insects. While aphid honeydew is primarily considered to comprise sugars and amino acids, its protein diversity has yet to be documented. Here, we report on the investigation of the honeydew proteome from the pea aphid Acyrthosiphon pisum. Using a two-Dimensional Differential in-Gel Electrophoresis (2D-Dige) approach, more than 140 spots were isolated, demonstrating that aphid honeydew also represents a diverse source of proteins. About 66% of the isolated spots were identified through mass spectrometry analysis, revealing that the protein diversity of aphid honeydew originates from several organisms (i.e. the host aphid and its microbiota, including endosymbiotic bacteria and gut flora). Interestingly, our experiments also allowed to identify some proteins like chaperonin, GroEL and Dnak chaperones, elongation factor Tu (EF-Tu), and flagellin that might act as mediators in the plant-aphid interaction. In addition to providing the first aphid honeydew proteome analysis, we propose to reconsider the importance of this substance, mainly acknowledged to be a waste product, from the aphid ecology perspective.

Optimisation of a semiochemical slow-release alginate formulation attractive towards Aphidius ervi Haliday parasitoids.

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-ß-farnesene and E-ß-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow-release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca(2+)). Other formulation parameters were optimised: ionic strength (0.5 M), Ca(2+) (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl(2) solution (48 h). After physical characterisation of beads, semiochemical slow-release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 µg of E-ß-farnesene and 1791 µg of E-ß-caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E-ß-farnesene and E-ß-caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow-release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields.

Microorganisms from aphid honeydew attract and enhance the efficacy of natural enemies.

Aphids are one of the most serious pests of crops worldwide, causing major yield and economic losses. To control aphids, natural enemies could be an option but their efficacy is sometimes limited by their dispersal in natural environment. Here we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which acts as a kairomone enhancing the efficiency of aphid natural enemies. Our findings represent the first case of a host-associated bacterium driving prey location and ovipositional preference for the natural enemy. We show that this bacterium has a key role in tritrophic interactions because it is the direct source of volatiles used to locate prey. Some specific semiochemicals produced by S. sciuri were also identified as significant attractants and ovipositional stimulants. The use of this host-associated bacterium could certainly provide a novel approach to control aphids in field and greenhouse systems.

Placenta-like structure of the aphid endoparasitic wasp Aphidius ervi: a strategy of optimal resources acquisition.

Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body.

Isolation, pure culture and characterization of Serratia symbiotica sp. nov., the R-type of secondary endosymbiont of the black bean aphid Aphis fabae.

An intracellular symbiotic bacterium was isolated from the flora of a natural clone of the black bean aphid Aphis fabae. The strain was able to grow freely in aerobic conditions on a rich medium containing 1 % of each of the following substrates: glucose, yeast extract and casein peptone. Pure culture was achieved through the use of solid-phase culture on the same medium and the strain was designated CWBI-2.3(T). 16S rRNA gene sequence analysis revealed that strain CWBI-2.3(T) was a member of the class Gammaproteobacteria, having high sequence similarity (>99 %) with 'Candidatus Serratia symbiotica', the R-type of secondary endosymbiont that is found in several aphid species. As strain CWBI-2.3(T) ( = LMG 25624(T) = DSM 23270(T)) was the first R-type symbiont to be isolated and characterized, it was designated as the type strain of Serratia symbiotica sp. nov.