Carapace ontogeny of the bromeliad dwelling ostracod Elpidium bromeliarum Müller, 1880 (Crustacea: Ostracoda)

Ostracods have discontinuous development, marked by ecdyses, and determinate growth. Ontogenetic studies have suggested a pattern of nine postembryonic stages (eight juvenile phases and the adult) for the main freshwater ostracod superfamilies Cypridoidea, Cytheroidea and Darwinuloidea. However, cases of a supposed extra moult in the adult stage have been proposed for some ostracod species, which would amount to 10 postembryonic growth stages. One such example is Elpidium bromeliarum Müller, 1880, a cytheroidean that inhabits tank-bromeliads. The present study is aimed at investigating the ontogenetic development of E. bromeliarum using width and length measurements, as well as carapace and appendage morphology in order to test the existing hypothesis of an additional growth stage in adults of this species. Our results revealed nine postembryonic growth stages (eight juvenile and the adult), with sexual dimorphism beginning its expression in the last juvenile stage. Thus, the ontogenetic development of E. bromeliarum agrees with the overall pattern observed for podocopid ostracods and the hypothesis of 10 postembryonic growth stages was not corroborated. We argue that the inability to differentiate juveniles from adults, or different species from one another, may have misled to the assumption of an additional moult in E. bromeliarum.     

Action Research in Reverse Logistics for End-Of-Life Tire Recycling

At the end of their product life cycle, tires require special handling and treatment in order to avoid damaging the environment and society. Reverse Logistics (RL) is necessary to manage this type of solid waste. In Brazilian cities, collection is one of the bottlenecks. One of the main difficulties in this process is enabling joint-action between the main stakeholders: Final consumers, the government and private companies. The main objective of this paper is to identify e implement opportunities for improvement in the collection phase of end-of-life tires through action-research, involving simultaneous participation between public and private organizations. The motive for this is that the knowledge generated can serve as a basis of information and references which aid in decision-making for public authorities who need to start similar programs or improve existing ones. The Action-Research occurred in a Brazilian city with less than 100,000 inhabitants, which fits the profile of 94.91% of the country’s municipalities. Final results proved the efficiency of the action-research proposal; after implementing the changes, the monthly collections grew by 50% (action), and the Action-Research team was able to generate and document knowledge which can now help other cities to improve their own processes.     

Mitochondria dynamism: of shape,transport and cell migration

Mitochondria are highly dynamic and functionally versatile organelles that continuously fragment and fuse in response to different physiological needs of the cell. The list of proteins that strictly regulate the morphology of these organelles is constantly growing, adding new players every day and new pieces to the comprehension and elucidation of this complex machinery. The structural complexity of mitochondria is only paralled by their functional versatility. Indeed, changes in mitochondria shape play critical roles in vertebrate development programmed cell death and in various processes of normal cell physiology, such as calcium signaling, reactive oxygen species production, and lifespan. Here, we present the latest findings on the regulation of mitochondrial dynamics and some of their physiological roles, focusing on cell migration. In cells where migration represents a crucial function in their physiology, such as T and tumoral metastatic cells, mitochondria need to be fragmented and recruited to specific subcellular regions to make movement possible. In depth analysis of this role of mitochondrial dynamics should help in identifying potential targeted therapy against cancer or in improving the immune system’s efficiency.     

A new quaternary ammonium compound with plant growth regulatory activity

Summary Of several quaternary ammonium derivatives tested, 1-allyl-1-(3,7-dimethyloctyl)piperidinium bromide showed the best growth-retarding activity. OnChrysanthemum morifolium the growth retardation obtained with a single application of 100–200 ppm compared favourably with that obtained from 2–3 applications of 3400 ppm of N-dimethylaminosuccinamic acid (daminozide).     

Regulation of calcium signalling in T lymphocytes by the second messenger cyclic ADP-ribose

Cyclic ADP-ribose (cADPR) is a natural compound that mobilizes calcium ions in several eukaryotic cells. Although it can lead to the release of calcium ions in T lymphocytes, it has not been firmly established as a second messenger in these cells. Here, using high-performance liquid chromatography analysis, we show that stimulation of the T-cell receptor/CD3 (TCR/CD3) complex results in activation of a soluble ADP-ribosyl cyclase and a sustained increase in intracellular levels of cADPR. There is a causal relation between increased cADPR concentrations, sustained calcium signalling and activation of T cells, as shown by inhibition of TCR/CD3-stimulated calcium signalling, cell proliferation and expression of the early- and late-activation markers CD25 and HLA-DR by using cADPR antagonists. The molecular target for cADPR, the type-3 ryanodine receptor/calcium channel, is expressed in T cells. Increased cADPR significantly and specifically stimulates the apparent association of [3H]ryanodine with the type-3 ryanodine receptor, indicating a direct modulatory effect of cADPR on channel opening. Thus we show the presence, causal relation and biological significance of the major constituents of the cADPR/calcium-signalling pathway in human T cells.