Anatomy and Ultrastructure of Galls Induced by Neuroterus quercusbaccarum (Hymenoptera: Cynipidae) on Oak Leaves (Quercus robur)

The structure and ultrastructure of two developmental stages of the spangle gall induced by Neuroterus quercusbaccarum (Hymenoptera, Cynipidae) were investigated using light microscopy (LM), fluorescence microscopy (FM), and transmission (TEM) and scanning (SEM) electron microscopy. The general design of the gall structure was typical of Cynipidae, but some structural features distinguished the spangle gall. Previously undescribed, characteristic multicellular epidermal protuberances with large openings were observed in autumn on the surface of galls. These may facilitate the gas exchange between the atmosphere and the inside of the gall, thus assisting larval respiration. The larval chamber is surrounded by both a sclerenchymatous capsule and numerous cells containing calcium oxalate crystals that may both serve as protective barriers. In young galls, the nutritive tissue is a wall-less protoplasmic mass, potentially easily accessible to young larvae with delicate mandibles. Cell walls only develop at a later stage. The nutritive tissue was found to be rich in proteins and lipids, but starch grains were not observed. Cellular topology suggests that spangle galls grow by anticlinal division of marginal epidermal cells and periclinal division of subepidermal cells. Cellular proliferation (hyperplasia) also occurs in the leaf tissue near the connection with the gall peduncle, which eventually lignifies.

Hydrogen sulfide facilitates reprogramming and trans-differentiation in 3D dermal fibroblast

The efficiency of cell reprogramming in two-dimensional (2D) cultures is limited. Given that cellular stemness is intimately related to microenvironmental changes, 3D cell cultures have the potential of overcoming this limited capacity by allowing cells to self-organize by aggregation. In 3D space, cells interact more efficiently, modify their cellular topology, gene expression, signaling, and metabolism. It is yet not clear as how 3D culture environments modify the reprogramming potential of fibroblasts. We demonstrate that 3D spheroids from dermal fibroblasts formed under ultra-low attachment conditions showed increased lactate production. This is a requisite for cell reprogramming, increase their expression of pluripotency genes, such as OCT4, NANOG and SOX2, and display upregulated cystathionine-β-synthase (CBS) and hydrogen sulfide (H2S) production. Knockdown of CBS by RNAi suppresses lactic acid and H2S production and concomitantly decreases the expression of OCT4 and NANOG. On the contrary, H2S donors, NaHS and garlic-derived diallyl trisulfide (DATS), promote the expression of OCT4, and support osteogenic trans-differentiation of fibroblasts. These results demonstrate that CBS mediated release of H2S regulates the reprogramming of dermal fibroblasts grown in 3D cultures and supports their trans-differentiation.

Projection of Sensitive Reality into Cellular Topology

The purpose of this paper is to discuss about the abstract representation of some reality in a given referential into a cellular topology[1]. From this projection, tensorial algebra can then be employed to translate mathematically the behavior of this perceptible reality[2]. The first discussion wears on an experience realized on some object. We speak firstly of the perception of the object. How it can be seen, identified depending on various point of views. It fixes the reference frame where the observation is made. In this reference frame, environment involves domains for which parameters are defined: temperature, pressure, etc. A stimulus can be applied on known conditions in this environment and defined observable can be measured. From this pragmatic but stilling complex experience, a law can be extracted giving a relation between the stimulus and the observable. This law can be seen as a function, part of a non-linear metric when the same object is enclosed in a larger system[3]. Conditions on the domains and experiences must be detailed in order to control the system behavior, but masked parameters can influence the evolution of the system, being possible explanations for emergences. The whole system is modeling using “gamma matrices”, transformers and “tenfolds”.

A Taxonomy for Representing Prismatic Cellular Materials

A taxonomy is developed to describe prismatic cellular materials (PCM) explicitly to allow for unambiguous discussion of cellular topology. The taxonomy represents a PCM through describing (1) the unit cell (UC) and (2) the tiling or unit cell arrangements. The UC is described through three characteristics: boundary, interior, and connections of the unit cell with its adjacent structural members. Each of these are further refined into sub-divisions. The taxonomy is evaluated through three metrics: completeness, perceptual orthogonality, and depth. Using this descriptive taxonomy, researchers can more uniformly describe the development efforts that they are pursuing.