Insects express 3 lines of protection from infections and invasions. Their cuticles and peritrophic membranes are physical barriers. Infections and invasions are quickly recognized within insect bodies, and recognition launches 2 lines of innate immune reactions. Humoral reactions involve induced synthesis of antimicrobial peptides, the bacteriolytic enzyme lysozyme and activation of the prophenoloxidase system. Cellular immune reactions include phagocytosis, nodulation and encapsulation. These reactions entail direct interactions between circulating hemocytes and the invaders. Cellular immune reactions begin immediately after an invasion is detected while antimicrobial peptides typically appear in the hemolymph some hours after infection. Microaggregation is a step in the nodulation process, which is responsible for clearing the bulk of bacterial infections from circulation. Coordinated cellular actions lead to encapsulation of invaders, such as parasitoid eggs, that are very much ...

Nodulation is the first and quantitatively most important cellular defense reaction to bacterial infections in insects. Treating adults of the 17-year periodical cicadas, Magicicada septendecim and M. cassini, with eicosanoid biosynthesis inhibitors immediately prior to intrahemocoelic injections of the bacterium, Serratia marcescens, sharply reduced the nodulation response to bacterial challenges. Separate treatments with specific inhibitors of phospholipase A2, cyclooxygenase, and lipoxygenase reduced nodulation, supporting our view that nodule formation is a multi-step process in which individual steps are separately mediated by lipoxygenase and cyclooxygenase products. The inhibitory influence of dexamethasone was apparent by 2 h after injection, and nodulation was significantly reduced, relative to control insects, over the following 14 h. The dexamethasone effects were reversed by treating bacteria-challenged insects with the eicosanoid-precursor polyunsaturated fatty acid, arachidonic acid. Low levels of arachidonic acid were detected in fat body phospholipids. These findings in adults of an exopterygote insect species with an unusual life history pattern broaden our hypothesis that eicosanoids mediate cellular immune reactions to bacterial infections in most, if not all, insects.

Abstract The present work mainly focused on the susceptibility of Schistocerca gregaria (Forskal( 5th instar nymphs to the entomopathogenic nematodes, Steinernema glaseri (Rhabditida: Steinernematidae) as a natural exposure experiment. The entomopathogenic nematode, S. glaseri turned out to be successful parasitoid of the orthopteran insect S. gregaria. The death rate of locusts (sprayed with nematode on clover leafs) was remarkably high. Nematode killed approximately 65% of the locust with in72 hours post infection at semi-field trial. The impact of parasitation on locusts' immune defense was closely investigated for S. gregaria parasitized by S. glaseri. Nymphs died within 48-72 h after being fed clover leafs contaminated with 1500/ml S. glaseri juveniles or previously contaminated with the dual cyclooxygenase/lipoxygenase inhibitor, phenidone. The injection of S. gregaria nymphs with, phenidone exhibited significant reduction in microaggegation in response to the nematode injections. At 12 h post-injection, insignificant differences were recorded of the individual inhibitor on microaggregation, compared to the ethanol-treated (control) nymphs. Cellular defense components were strongly influenced by parasitation within the first 12 h after injection of the nematodes. Nymph's haemolymph was assayed.

Eicosanoids are lipid mediators with multiple functions in vertebrate tissues and invertebrate organisms. In this review the roles of eicosanoids--mostly prostaglandins (PGs), thromboxanes and leukotrienes--in parasite physiology and host-parasite interactions are discussed. PGs are present in the saliva of blood-sucking arthropods facilitating feeding by increasing local blood flow and prolonged attachment of ticks by immune suppression. Release of various eicosanoids has also been demonstrated for a number of protozoan and metazoan endoparasites. These substances appear to play a role in penetration, immune suppression, inflammation or modulation of haemostasis, enabling parasite invasion and establishment. Moreover, endogenous eicosanoids serve various functions in parasite metabolism and physiology. In many parasitic infections eicosanoids are involved in host pathology, e.g. granuloma formation, coagulopathy, secretory diarrhoea, or fever. Immune suppression by induction of PG ...

1) Nodulation is the first, and qualitatively predominant, cellular defense reaction to bacterial infections in insects and other invertebrates; 2) treating silkworms, Bombyx mori, with the eicosanoid biosynthesis inhibitor, dexamethasone, strongly reduced nodulation responses to bacterial infections; 3) the influence of dexamethasone was reversed by injecting the eicosanoid-precursor polyunsaturated fatty acid, arachidonic acid (20:4n-6), into dexamethasone-treated, infected larvae; 4) the presence of an eicosanoid biosynthesis system in silkworms was documented. Demonstrated elements include a digestive phospholipase A2, incorporation of exogenous 20:4n-6 into fat body phospholipids, the presence of 20:4n-6 in cellular phospholipids, a fat body intracellular phospholipase A2 that can hydrolyze 20:4n-6 from cellular phospolipids, and eicosanoid biosynthetic enzymes; and 5) these findings support the hypothesis that eicosanoids mediate cellular immune responses to bacterial infections in silkworms.

Mettre nos vies en accord avec nos paroles et nos écrits apparaît comme une exigence nouvelle à l'heure où les incertitudes sur le devenir de nos sociétés sont de plus en plus fortes. En adoptant une focale africaine, je voudrais envisager la littérature comme le lieu où nos manières de vivre sont mises en discussion dans un cercle très large, qui comprend les morts et leurs lieux. Si l'on attend de plus en plus clairement aujourd'hui que la littérature nous oblige, c'est peut-être qu'elle prend explicitement en charge les forces souterraines qui n'ont cessé de régir nos vies et qui sont récemment remontées en surface.

Every man is a creature of the age in which he lives and few are able to raise themselves above the ideas of the time. - Voltaire Mannheim and Historical Synergy: Mannheim's argument was pretty much common sense - that the economic - political reality would be a profound influence on worldviews and the social sciences - philosophy, psychology, political science - and even spiritual and religious views. Common sense would seem to dictate that peoples' worldviews and orientations would necessarily adopt and adjust to the economic-political “reality” and “the physical world” they live in. Historically that has proved to be a good rule of thumb - though not perfect pattern as it were. Mannheim's worldview was in line with many other philosophers of his time - Nietzsche, Gasset, etc. And as Voltaire observed, “Every man is a creature of the age in which he lives and few are able to raise themselves above the ideas of the time.” Unfortunately, even with scholars and scientists today that is too true. For perspective, there is a big difference between reason and rational analysis. Rational analysis is viewed by some as inherently good. Rational analysis is a tool – used by the Nazi’s to improve the efficiency of their death camps or by scientists to improve food production. Similarly, there is a huge difference between the Age of Reason and this new Age of Materialism. The widespread view of truth as conditional and in part a product of social convention (Nietzsche or circumstances (Gasset), materialist thinking and methodology is intolerant and absolute because of the emphasis on quantification Esther, the administrator for a "neuroscience" FB group, sent me a message stating, “Esther ************ Charles Peck Jr "there are theorists from years ago who were not as scientific as more modern theorists. That is because we follow the scientific method and therefore our theories are raised from scientific deduction through the empirical method. Our practices today are not just cooked up in simple observations or hearsay. Practices and approaches are not philosophies but scientifically repeatable theories and laws (not just hunches and hypothesis).” From discussions, I would say that view of science in terms of an absolute is common and widespread. Nietzsche, Gasset and Mannheim were discarded by the new materialists. They also ignore modern neuroscientists like Damasio. Antonio Damasio, the famous neuroscientist states, in Descartes' Error: Emotion, Reason, and the Human Brain (2005), “I am skeptical of science’s presumption of objectivity and definitiveness. I have difficulty in seeing scientific results, especially in neurobiology, as anything but provisional approximations.” Materialist Methodology “severely restricts and limits the analyses that can be performed The bottom line is materialists ‘came into power’ and became the dominant force in the academic institution – and brought with them the argument that quantification makes science infallible. From a purely scientific view – it is the opposite as McGilChrist points out. As Claudia Nielsen pointed out, the psychiatrist McGilChrist observes that “The scope of inquiry and understanding of the Materialist Doctrine with its rigid adherence to the actually arbitrary principle of quantification and over-emphasis on physiological characteristics is severely restricted and limited in the analyses that can be performed.” Half of human conscious is not quantifiable: hope, art, dreams, music, poetry, true love, awe-wonder, freedom, ideals, justice, - not to mention death. I would briefly question that how a methodology – described by McGilChrist as a “rigid adherence to quantification” – which is appropriate to physics or chemistry got applied to human consciousness is mindboggling. I would add that – if you take a close look at the social sciences, the materialist methodology has generated a rather serious from of researcher bias – no viable form of social consciousness, no spiritual and religious beliefs as a drive and motivation, no “community” in the “universally accepted definition of religion”, no readily apparent prosocial norms inherent in psychology theories (i.e social cognitive theory – weak on motivation)