Childhood adversities and psychosis: evidence,challenges, implications

There is a substantial body of research reporting evidence of associations between various forms of childhood adversity and psychosis, across the spectrum from experiences to disorder. This has been extended, more recently, to include studies of cumulative effects, of interactions with other factors, of specific effects, and of putative biological and psychological mechanisms. In this paper we evaluate this research and highlight the remaining methodological issues and gaps that temper, but do not dismiss, conclusions about the causal role of childhood adversity. We also consider the emerging work on cumulative, synergistic, and specific effects and on mechanisms; and discuss the broader implications of this line of research for our understanding of psychosis. We conclude that the current balance of evidence is that childhood adversities – particularly exposure to multiple adversities involving hostility and threat – do, in some people, contribute to the onset of psychotic experiences and psychotic disorders.     

Production of biomass and useful compounds from adventitious roots of high-value added medicinal plants using bioreactor

The increasing global demand for biomass of medicinal plant resources reflects the issues and crisis created by diminishing renewable resources and increasing consumer populations. Moreover, diverse usage of plants and reduced land for cultivation in the world accelerated the deficiency of plant resources. In addition, the preparation of safety of plant based medicine whips up demand for biomass of valuable medicinal plants. As one of alternative approach to upswing the productivity of plant-based pharmaceutical compounds, automation of adventitious root culture system in air-lift bioreactor was adopted to produce cosmic amount of root biomass along with enriched diverse bioactive molecules. In this review, various physiological, engineering parameters, and selection of proper cultivation strategy (fed-batch, two-stage etc.) affecting the biomass production and secondary metabolite accumulation have been discussed. In addition, advances in adventitious root cultures including factors for process scale-up as well as recent research aimed at maximizing automation of the bioreactor production processes are also highlighted. Examples of the scale-up of cultures of adventitious roots of Morinda citrifolia, Echinacea purpurea and angustifolia, Hypericum perforatum and Panax ginseng by applying 20L to 10,000L bioreactors in our lab were demonstrated with a view of commercial application.     

Comparison of Cell Growth and Alkaloid Production of Catharanthus roseus Cells Cultured in Shake Flask and in Bioreactor

The cell growth and alkaloid production of Catharanthus roseus (L.) G. Don cells cultured in the shake flasks with different volumes and in the stirred tank bioreactor (10 L) were compared. Cell dry weight and alkaloid production showed no significant difference in the small volume scale-up shake flasks. When more broths were added to a certain volume in the shake flask, both cell weight and alkaloid production were decreased. The maximum cell dry weight was similar between the cell cultures in the shake flask and the bioreactor, but the alkaloid production of cells was much less in the bioreactor. Gas regime and shear stress were recognized to be the main factors contributing the important effect on alkaloid production during the scale-up processes.     

A microwell platform for the scale-up of a multistep bioconversion to bench-scale reactors: Sitosterol side-chain cleavage

The microwell-scale approach is widely used for screening purposes and one-pot biotransformations, but it has seldom been applied to complex whole cell multistep bioconversions, requiring prolonged incubation periods. The present study aims to contribute to filling this gap. The side-chain cleavage of sitosterol to androstenedione (AD) with Mycobacterium sp. NRRL B-3805 cells was used as a model system, and focus was given to the screening of suitable bioconversion media with 24-well microwell plates. Results show that to perform this particular bioconversion growing cells are preferred over resting cells due to higher conversion yields obtained in aqueous medium. The use of resting cells may nevertheless present an interesting approach provided catalytic activity is retained throughout successive runs. Maintaining suitable aeration levels (air flow of 1 mL/min) allowed minimizing the decay of catalytic activity typically observed alongside consecutive bioconversion runs with resting cells. Microwell plates with dedicated oxygen and pH monitoring capabilities proved effective in media development for complex multistep bioconversions using relatively slow-growing bacteria. Under constant k_La (0.044/s) similar AD production and dissolved oxygen profiles were observed in microwell plates and in a bench-scale reactor. Selection of a suitable k_La value proved critical, since under lower k_La values scale-up proved unsuccessful. The same pattern was observed when other scale-up criteria were evaluated to perform the scale-up of this particular bioconversion. Results gathered seem to validate the proposed approach “from microwell plate to bench-scale fermentor”.     

Academic network for nature conservation in Tandilia System,Buenos Aires,Argentina

The Tandilia System, located in the Southern Pampa region of Argentina, contains areas with conservation value scattered throughout its agricultural landscape. Unfortunately, efforts for their conservation and sustainable management are scarce and isolated, which may be explained by the lack of articulation and linkage between the different social actors in the territory. Based on 123 surveys of academics working in this field, we analyzed research lines, management and outreach experiences, and the synergies and interactions between them. The most frequent research topics were related to biodiversity, terrestrial ecosystems, landscapes, anthropic pressures, and environmental management. Twenty-six environmental management experiences were reported in which the creation and/or planning of protected areas were the most frequent. The analysis of academic-social networks allowed us to explore the relationship between actors. A high degree of network modularity was identified, with strong links within the research groups, but few connections between them. In general terms, these connections depend on a few actors with a high degree of intermediation. Additionally, some professionals presented a high degree of betweenness, which is an important potential for the efficient coordination of conservation and management projects. Our results suggest the relevance of fostering greater interaction between professionals and research groups, as well as of promoting joint management activities concerning nature care in the Tandilia System.     

Isolation of a novel high erythritol-producing <Emphasis Type="Italic">Pseudozyma tsukubaensis</Emphasis> and scale-up of erythritol fermentation to industrial level

This study isolated a novel erythritol-producing yeast strain, which is capable of growth at high osmolarity. Characteristics of the strain include asexual reproduction by multilateral budding, absence of extracellular starch-like compounds, and a negative Diazonium blue B color reaction. Phylogenetic analysis based on the 26S rDNA sequence and physiological analysis indicated that the strain belongs to the species Pseudozyma tsukubaensis and has been named P. tsukubaensis KN75. When P. tsukubaensis KN75 was cultured aerobically in a fed-batch culture with glucose as a carbon source, it produced 245 g/L of erythritol, corresponding to 2.86 g/L/h productivity and 61% yield, the highest erythritol yield ever reported by an erythritol-producing microorganism. Erythritol production was scaled up from a laboratory scale (7 L fermenter) to pilot (300 L) and plant (50,000 L) scales using the dissolved oxygen as a scale-up parameter. Erythritol production at the pilot and plant scales was similar to that at the laboratory scale, indicating that the production of erythritol by P. tsukubaensis KN75 holds commercial potential.     

Revisiting the influence of learning in predator functional response,how it can lead to shapes different from type III

Predator/parasitoid functional response is one of the main tools used to study predation behavior, and in assessing the potential of biological control candidates. It is generally accepted that predator learning in prey searching and manipulation can produce the appearance of a type III functional response. Holling proposed that in the presence of alternative prey, at some point the predator would shift the preferred prey, leading to the appearance of a sigmoid function that characterized that functional response. This is supported by the analogy between enzyme kinetics and functional response that Holling used as the basis for developing this theory. However, after several decades, sigmoidal functional responses appear in the absence of alternative prey in most of the biological taxa studied. Here, we propose modeling the effect of learning on the functional response by using the explicit incorporation of learning curves in the parameters of the Holling functional response, the attack rate (a), and the manipulation time (h). We then study how the variation in the parameters of the learning curves causes variations in the shape of the functional response curve. We found that the functional response product of learning can be either type I, II, or III, depending on what parameters act on the organism, and how much it can learn throughout the length of the study. Therefore, the presence of other types of curves should not be automatically associated with the absence of learning. These results are important from an ecological point of view because when type III functional response is associated with learning, it is generally accepted that it can operate as a stabilizing factor in population dynamics. Our results, to the contrary, suggest that depending on how it acts, it may even be destabilizing by generating the appearance of functional responses close to type I.     

Single-cell-bioreactors as end of miniaturization approaches in biotechnology: progresses with characterised bioreactors and a glance into the future

Incidents with single cells and their genesis have not been the major focus of science up to now. This fact is supported by the difficulties one faces when wanting to monitor and cultivate small populations of cells in a defined compartment under controlled conditions, in vitro. Several approaches of up- and down-scaling have often led to poorly understood results which might be better elucidated by understanding the cellular genesis as a function of its microenvironment. This review of the approaches of scale-up and scale-down processes illustrates technical possibilities and shows up their limitations with regard to obtainable data for the characterisation of cellular genesis and impact of the cellular microenvironment. For example, stem cell research advances underline the lack of information about the impact of the microenvironment on cellular development. Finally, a proposal of future research efforts is given on how to overcome this lack of data via a novel bioreactor setup.     

Rotating biological contactors: a review on main factors affecting performance

Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, step-feeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.