A hungry need for knowledge on the black soldier fly digestive system

The interest towards the black soldier fly (BSF), Hermetia illucens, has grown impressively in the last few years, fostered by the legislative changes in the European landscape that have lifted the ban regarding the use of BSF larvae as feedstuff. In addition, bioconversion mediated by the larvae of the BSF is viewed as one of the most promising technologies for organic waste processing and valorisation. Finally, new, alternative applications to exploit various larval products such as lipids, chitin, antimicrobial peptides, and frass are being explored. However, this positive trend, confirmed by the increasing number of companies that deal with BSF mass rearing and processing, is in sharp contrast with the limited information on the biology of this insect, in particular on aspects related to its digestive features. This lack of knowledge needs to be carefully considered and filled in coming years, as a deep characterisation of the morphology, physiology, transcriptomics, and proteomics of the digestive system of the insect, as well a fine dissection of related aspects as gut microbiota and pathogens, is a prerequisite to improve the amazing bioconversion capabilities of this dipteron. So far, the larval stages received the most attention in research, but there might still be a lot to win by focusing more on the adult stage. Further expanding the basic knowledge on both the larval and the adult gut could lead to unexpected findings and open new perspectives to produce value-added bioproducts

Anomalous Perception of Biological Motion in Autism: A Conceptual Review and Meta-Analysis

Despite its popularity, the construct of biological motion (BM) and its putative anomalies in autism spectrum disorder (ASD) are not completely clarified. In this article, we present a meta-analysis investigating the putative anomalies of BM perception in ASD. Through a systematic literature search, we found 30 studies that investigated BM perception in both ASD and typical developing peers by using point-light display stimuli. A general meta-analysis including all these studies showed a moderate deficit of individuals with ASD in BM processing, but also a high heterogeneity. This heterogeneity was explored in different additional meta-analyses where studies were grouped according to levels of complexity of the BM task employed (first-order, direct and instrumental), and according to the manipulation of low-level perceptual features (spatial vs. temporal) of the control stimuli. Results suggest that the most severe deficit in ASD is evident when perception of BM is serving a secondary purpose (e.g., inferring intentionality/action/emotion) and, interestingly, that temporal dynamics of stimuli are an important factor in determining BM processing anomalies in ASD. Our results question the traditional understanding of BM anomalies in ASD as a monolithic deficit and suggest a paradigm shift that deconstructs BM into distinct levels of processing and specific spatio-temporal subcomponents

Dynamical and stationary critical behavior of the Ising ferromagnet in a thermal gradient

In this paper we present and discuss results of Monte Carlo numerical simulations of the two-dimensional Ising ferromagnet in contact with a heat bath that intrinsically has a thermal gradient. The extremes of the magnet are at temperatures $T_1<T_c<T_2$, where $T_c$ is the Onsager critical temperature. In this way one can observe a phase transition between an ordered phase ($TT_c$) by means of a single simulation. By starting the simulations with fully disordered initial configurations with magnetization $m\equiv 0$ corresponding to $T=\infty$, which are then suddenly annealed to a preset thermal gradient, we study the short-time critical dynamic behavior of the system. Also, by setting a small initial magnetization $m=m_0$, we study the critical initial increase of the order parameter. Furthermore, by starting the simulations from fully ordered configurations, which correspond to the ground state at T=0 and are subsequently quenched to a preset gradient, we study the critical relaxation dynamics of the system. Additionally, we perform stationary measurements ($t\rightarrow\infty$) that are discussed in terms of the standard finite-size scaling theory. We conclude that our numerical simulation results of the Ising magnet in a thermal gradient, which are rationalized in terms of both dynamic and standard scaling arguments, are fully consistent with well established results obtained under equilibrium conditions

A viral chitinase enhances oral activity of TMOF

In this study we investigate the combined effect on Heliothis virescens (Lepidoptera, Noctuidae) larvae of Aedes aegypti-Trypsin Modulating Oostatic Factor (. Aea-TMOF), a peptide that inhibits trypsin synthesis by the gut, impairing insect digestive function, and Autographa californica nucleopolyhedrovirus Chitinase A (AcMNPV ChiA), an enzyme that is able to alter the permeability of the peritrophic membrane (PM). Aea-TMOF and AcMNPV ChiA were provided to the larvae by administering transgenic tobacco plants, co-expressing both molecules. Experimental larvae feeding on these plants, compared to those alimented on plants expressing only one of the two molecules considered, showed significantly stronger negative effects on growth rate, developmental time and mortality. The impact of AcMNPV ChiA on the PM of H. virescens larvae, measured as increased permeability to molecules, was evident after five days of feeding on transgenic plants expressing ChiA. This result was confirmed by in vitro treatment of PM with recombinant ChiA, extracted from the transgenic plants used for the feeding experiments. Collectively, these data indicate the occurrence of a positive interaction between the two transgenes concurrently expressed in the same plant. The hydrolytic activity of ChiA on the PM of tobacco budworm larvae enhances the permeation of TMOF molecules to the ectoperitrophic space, and its subsequent absorption. The permeation through the paracellular route of Aea-TMOF resulted in a spotted accumulation on the basolateral domain of enterocytes, which suggests the occurrence of a receptor on the gut side facing the haemocoel. The binding of the peptide, permeating at increased rates due to the ChiA activity, is considered responsible for the enhanced insecticide activity of the transgenic plants expressing both molecules. These data corroborate the idea that ChiA can be effectively used as gut permeation enhancer in oral delivery strategies of bioinsecticides targeting haemocoelic receptors

Polypeptides from Hermetia illucens: a bio source for innovative materials in the framework of a circular economy model

Plastic waste reduction is one of the main challenges of the 21st century from an environmental and sustainability perspective. Still nowadays, relatively little plastic waste is collected for recycling (less than 10%) and a large fraction (approximately 20%) of Municipal Solid Waste (MSW) goes to landfill. At the global level, the generation of municipal solid waste (MSW) is estimated to be 2.5 billion tonnes per year, of which 30-55% is represented by the so-called organic fraction of municipal solid waste (OFMSW). While the use of alternative, plastic-like materials from natural sources could be one of the most appealing solutions, the massive occupation of agricultural soils for their supply is a big concern. In this scenario, waste valorization is gaining major relevance within the framework of circular economy models, with bio-conversion mediated from insects being one possible and effective answer. The project RICH (Turning Rubbish Into biobased materials: a sustainable CHain for the full valorization of organic waste) aims to develop an innovative and integrated circular economy chain, which, starting from the biotransformation of the organic fraction of municipal solid waste (OFMSW), allows the targeted production of biobased materials with high technological value, such as bioplastics and other advanced protein-based materials. In the present study, proteins and polypeptides were extracted from larvae of Hermetia illucens, also known as black soldier fly. Extracts were characterized by means of proteomics techniques such as BCA, SDSPAGE, and LC-MS analyses. Procedures were next defined to prepare materials such as films, tuning the mechanical properties, and investigating the correlation with the molecular structure. Elastic films were obtained and the elasticity was correlated with the chemical composition and the protocol for film preparation. The results so far obtained pave the way for the application of these materials in the biomedical and packaging fields, bringing us closer to the completion of a new circular economy model

Insights Into the Immune Response of the Black Soldier Fly Larvae to Bacteria

In insects, a complex and effective immune system that can be rapidly activated by a plethora of stimuli has evolved. Although the main cellular and humoral mechanisms and their activation pathways are highly conserved across insects, the timing and the ef\ufb01cacy of triggered immune responses can differ among different species. In this scenario, an insect deserving particular attention is the black soldier \ufb02 y (BSF), Hermetia illucens (Diptera: Stratiomyidae). Indeed, BSF larvae can be reared on a wide range of decaying organic substrates and, thanks to their high protein and lipid content, they represent a valuable source of macromolecules useful for different applications (e.g., production of feedstuff, bioplastics, and biodiesel), thus contributing to the development of circular economy supply chains for waste valorization. However, decaying substrates bring the larvae into contact with different potential pathogens that can challenge their health status and growth. Although these life strategies have presumably contributed to shape the evolution of a sophisticated and ef \ufb01 cient immune system in this dipteran, knowledge about its functional features is still fragmentary. In the present study, we investigated the processes underpinning the immune response to bacteria in H. illucens larvae and characterized their reaction times. Our data demonstrate that the cellular and humoral responses in this insect show different kinetics: phagocytosis and encapsulation are rapidly triggered after the immune challenge, while the humoral components intervene later. Moreover, although both Gram-positive and Gram-negative bacteria are completely removed from the insect body within a few hours after injection, Gram-positive bacteria persist in the hemolymph longer than do Gram-negative bacteria. Finally, the activity of two key actors of the humoral response, i.e., lysozyme and phenoloxidase, show unusual dynamics as compared to other insects. This study represents the \ufb01 rst detailed characterization of the immune response to bacteria of H. illucens larvae, expanding knowledge on the defense mechanisms of this insect among Diptera. This information is a prerequisite to manipulating the larval immune response by nutritional and environmental factors to increase resistance to pathogens and optimize health status during mass rearing

Innovative bioplastics from polypeptides of Hermetia illucens

The environmentally sustainable waste management, together with waste valorization, is one of the actual challenges pursued by the European Commission. UE policies are thus contributing in the frameworks of circular economy by promoting the extraction of high quality materials from wastes. At the European level, the generation of municipal solid waste (MSW) is estimated to be 500 kg per capita, of which 70% (discarded food, yard trimmings, paper and wood) is represented by the so-called organic fraction of municipal solid waste (OFMSW). In this scenario, organic waste valorization is gaining major relevance within circular economy models, with bioconversion mediated from insects being one possible and effective answer to the problem. The project RICH (Turning Rubbish Into biobased materials: a sustainable CHain for the full valorization of organic waste) aims to develop an innovative and integrated circular economy chain, which, starting from the biotransformation of the organic fraction of municipal solid waste (OFMSW), allows the targeted production of biobased materials with high technological value, such as bioplastics and other advanced protein-based materials. In the present study, proteins and polypeptides were extracted from larvae and pupae of Hermetia illucens, also known as Black Soldier Fly. The extraction efficiency from both stages was assessed. Crude extracts were characterized by means of proteomics techniques such as BCA, SDS-PAGE, and LC-MS analyses. State of art materials were prepared, investigating the correlation with the molecular structure through physical techniques (FTIR, Contact Angle, TGA). Results clearly points out a correlation between film-forming ability and the chosen larval stage, with extracts from Larvae at the 6th instar leading to the best results. A correlation with polypeptide chain length is proposed

Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase

Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex

Determining the reference range of blood presepsin in term and preterm neonates

Introduction Sepsis is still a major cause of morbidity and mortality in neonates, especially in preterm infants. Mortality can reach 60-70% in very low birth weight infants (birthweight 0.20). This reduced model explains 3.8% of the total sum of squares. After adjustment for all the factors in the model, presepsin levels appear to be significantly lower in twins (496 pg/ml \uf0b1 65.5 vs 655 pg/ml \uf0b1 11.8) and in neonates with Apgar at 1 min 658 (644 pg/ml \uf0b1 11.8 vs 774 pg/ml \uf0b1 56.2). So none of the above factors seems worth to be taken into account in determining the reference limits for presepsin blood levels in healthy term neonates. Preterm neonates. The largest differences in presepsin level are observed between small for gestational age (SGA) (903 pg/ml \uf0b1 57.1) and adequate for gestational age (AGA) neonates (703 pg/ml \uf0b1 26.7), between neonates with and without mechanical ventilation at blood sampling (1090 pg/ml \uf0b1 86.9 vs 711 pg/ml \uf0b1 24.7) and at delivery (855 pg/ml \uf0b1 87.3 vs 729 pg/ml \uf0b1 25.8), between neonates with and without venous catether (801 pg/ml \uf0b1 47.5 vs 716 pg/ml \uf0b1 28.9), between neonates who underwent blood sampling after the 4th day or before (797 pg/ml \uf0b1 46.2 vs 716 pg/ml \uf0b1 29.2), between males and females (778 pg/ml \uf0b1 35.1 vs 701 pg/ml \uf0b1 34.7). All these factors, when simultaneously introduced into a multivariable linear model, explain only 18.8% of the total sum of squares. A second multivariable linear model was fitted after removing the factors that showed the lowest effect on presepsin level (those associated with a p-value >0.50). This reduced model explains 13.4% of the total sum of squares. A third and more parsimonious multivariable linear model was fitted after removing the factors that showed the lowest effect on presepsin level (those associated with a p-value >0.20). This reduced model explains 12.3% of the total sum of squares. After adjustment for all the factors in the model, presepsin levels result to be significantly lower in AGA neonates (706 pg/ml \uf0b1 25.7 vs 890 pg/ml \uf0b1 55.0) and between neonates with and without mechanical ventilation at blood sampling (1074 pg/ml \uf0b1 85.3 vs 712 pg/ml \uf0b1 24.2). Even in this case, none of the above factors is expected to substantially affect the reference limits for presepsin blood levels in preterm neonates. Conclusion Presepsin blood levels seem to be quite independent of most of maternal and neonatal conditions examined in this study both in preterm and term neonates. The factors exerting significant effects (multiple birth and Apgar at 1 min, in term neonates, weight by gestational age and mechanical ventilation in preterm neonates) are expected to affect presepsin reference limits only to minor extent. References [1] Evaluation of a newly identified soluble CD14 subtype as a marker for sepsis. Yaegashi Y., Shirakawa K., Sato N., Suzuki Y., Kojika M., Imai S., Takahashi G., Miyata M., Furusako S., Endo S. J Infect Chemother. 2005;11:234-8. [2] CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infection in the acute care setting. Horan T.C., Andrus M., Dudeck M.A. Am J Infect Control. 2008;36:309-32