A critique of the “ultra‐high risk” and “transition” paradigm

The transdiagnostic expression of psychotic experiences in common mental disorder (anxiety/depression/substance use disorder) is associated with a poorer prognosis, and a small minority of people may indeed develop a clinical picture that meets criteria for schizophrenia. However, it appears neither useful nor valid to observe early states of multidimensional psychopathology in young people through the “schizo”‐prism, and apply misleadingly simple, unnecessary and inefficient binary concepts of “risk” and “transition”. A review of the “ultra‐high risk” (UHR) or “clinical high risk” (CHR) literature indicates that UHR/CHR samples are highly heterogeneous and represent individuals diagnosed with common mental disorder (anxiety/depression/substance use disorder) and a degree of psychotic experiences. Epidemiological research has shown that psychotic experiences are a (possibly non‐causal) marker of the severity of multidimensional psychopathology, driving poor outcome, yet notions of “risk” and “transition” in UHR/CHR research are restrictively defined on the basis of positive psychotic phenomena alone, ignoring how baseline differences in multidimensional psychopathology may differentially impact course and outcome. The concepts of “risk” and “transition” in UHR/CHR research are measured on the same dimensional scale, yet are used to produce artificial diagnostic shifts. In fact, “transition” in UHR/CHR research occurs mainly as a function of variable sample enrichment strategies rather than the UHR/CHR “criteria” themselves. Furthermore, transition rates in UHR/CHR research are inflated as they do not exclude false positives associated with the natural fluctuation of dimensional expression of psychosis. Biological associations with “transition” thus likely represent false positive findings, as was the initial claim of strong effects of omega‐3 polyunsatured fatty acids in UHR samples. A large body of UHR/CHR intervention research has focused on the questionable outcome of “transition”, which shows lack of correlation with functional outcome. It may be more productive to consider the full range of person‐specific psychopathology in all young individuals who seek help for mental health problems, instead of “policing” youngsters for the transdiagnostic dimension of psychosis. Instead of the relatively inefficient medical high‐risk approach, a public health perspective, focusing on improved access to a low‐stigma, high‐hope, small scale and youth‐specific environment with acceptable language and interventions may represent a more useful and efficient strategy.     

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.     

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.     

Optimization of culture conditions and scale-up to pilot and plant scales for coenzyme Q<Subscript>10</Subscript> production by <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

This report describes the optimization of culture conditions for coenzyme Q₁₀ (CoQ₁₀) production by Agrobacterium tumefaciens KCCM 10413, an identified high-CoQ₁₀-producing strain (Kim et al., Korean patent. 10-0458818, 2002b). Among the conditions tested, the pH and the dissolved oxygen (DO) levels were the key factors affecting CoQ₁₀ production. When the pH and DO levels were controlled at 7.0 and 0–10%, respectively, a dry cell weight (DCW) of 48.4 g l⁻¹ and a CoQ₁₀ production of 320 mg l⁻¹ were obtained after 96 h of batch culture, corresponding to a specific CoQ₁₀ content of 6.61 mg g-DCW⁻¹. In a fed-batch culture of sucrose, the DCW, specific CoQ₁₀ content, and CoQ₁₀ production increased to 53.6 g l⁻¹, 8.54 mg g-DCW⁻¹, and 458 mg l⁻¹, respectively. CoQ₁₀ production was scaled up from a laboratory scale (5-l fermentor) to a pilot scale (300 l) and a plant scale (5,000 l) using the impeller tip velocity (V _tip) as a scale-up parameter. CoQ₁₀ production at the laboratory scale was similar to those at the pilot and plant scales. This is the first report of pilot- and plant-scale productions of CoQ₁₀ in A. tumefaciens.     

Comparative evaluation of compact photobioreactors for large-scale monoculture of microalgae

Engineering analyses combined with experimental observations in horizontal tubular photobioreactors and vertical bubble columns are used to demonstrate the potential of pneumatically mixed vertical devices for large-scale outdoor culture of photosynthetic microorganisms. Whereas the horizontal tubular systems have been extensively investigated, their scalability is limited. Horizontal tubular photobioreactors and vertical bubble column type units differ substantially in many ways, particularly with respect to the surface–to–volume ratio, the amount of gas in dispersion, the gas–liquid mass transfer characteristics, the nature of the fluid movement and the internal irradiance levels. As illustrated for eicosapentaenoic acid production from the microalga Phaeodactylum tricornutum, a realistic commercial process cannot rely on horizontal tubular photobioreactor technology. In bubble columns, presence of gas bubbles generally enhances internal irradiance when the Sun is low on the horizon. Near solar noon, the bubbles diminish the internal column irradiance relative to the ungassed state. The optimal dimensions of vertical column photobioreactors are about 0.2 m diameter and 4 m column height. Parallel east–west oriented rows of such columns located at 36.8°N latitude need an optimal inter-row spacing of about 3.5 m. In vertical columns the biomass productivity varies substantially during the year: the peak productivity during summer may be several times greater than in the winter. This seasonal variation occurs also in horizontal tubular units, but is much less pronounced. Under identical conditions, the volumetric biomass productivity in a bubble column is 60% of that in a 0.06 m diameter horizontal tubular loop, but there is substantial scope for raising this value.     

Metarhizium anisopliae conidia production in packed-bed bioreactor using rice as substrate in successive cultivations

This paper presents a study on scale-up and cost reduction of the production of spores of Metarhizium anisopliae IBCB 425, entomopathogenic fungus used in sugarcane crops. Rice was mixed with sugarcane bagasse (9:1 w/w) for substrate composition, assuring adequate physical structure for cultivation in packed-beds. Spores yield from only rice in bench-scale packed-bed bioreactor was 56 % of the one obtained from the mixture 9:1 w/w. In comparison to plastic packages used in bioindustries, equivalent spores yields per gram of substrate have been achieved in bench and pilot-scale bioreactors built by cylindrical jacketed modules, that provide better control of operational and environmental variables, attested by little variability among replicates. Although non-negligible temperature rise (5 °C above the ideal) occurred within the pilot-scale bioreactor, spores production was not harmed in comparison to bench-scale. By reusing rice up to three successive cultivations, a 2.5-fold increase of spores yields was achieved in comparison to single use. Temperatures and CO₂ profiles corroborates the fungus adapted differently to substrate at each usage. Such results are valuable for industrial producers of commercial formulations of the fungus spores, allowing process modernization by using packed-bed bioreactors and production costs and rice demand reduction by recycling the substrate.     

Discursive constructions of race talk among Black men and women living in the United States

Race talk within discourse analytic traditions have largely focused on the discursive construction of racism in majority groups. This article extends this work by examining how Black adults discursively engaged in race talk. Across focus groups, two conversations emerged: explanations of racialized experiences and how racialized experiences should be dealt with. In explanations of racialized experiences, participants highlighted their own negative behaviours or constructed experiences as imprecise or an artefact of ignorance. These discourses functioned to circumvent inequitable relations premised on White normativity. In explanations of how racialized experiences should be dealt with, participants constructed themselves as having responsibilities, downplayed their racialized experiences or framed them as inevitable. Each of these discourses functioned to construct racialization as something that could be corrected through good behaviour or they placed ideological limits for what is possible for Blacks in society. Implications for the existing literature on race talk are discussed.     

Social representations of ‘mixed-race’ in early twenty-first-century Britain: content,limitations, and counter-narratives

Over the last two decades, lay and professional interest in Britain's ‘mixed-race’ population has markedly increased, following dramatic growth in mixing and mixedness. As is often the case with new phenomena, agencies in the sphere of popular culture have stepped in to offer the wider public interpretative representations of this ‘new’ group. Drawing on challenging concepts, like demographic growth rates and projections, the family ‘norm’, the ostensible benefits of heterozygosity, and the drawbacks of claimed ‘in-betweenness’, they have offered us a picture of the ‘mixed-race’ population that is sometimes at variance with lived experiences or the harder image of statistical reality. Social representation theory is used to explore the limitations of these representations and to offer a number of counter-narratives that are grounded in the evidence base.     

Self-experience in the early phases of schizophrenia: 5-year follow-up of the Copenhagen Prodromal Study

Despite the avalanche of empirical data on prodromal/"at risk" conditions, the essential aspects of the vulnerability to the schizophrenia spectrum remain largely unaddressed. We report here the results of the Copenhagen Schizophrenia Prodromal Study, a prospective, observational study of first admission patients in putative state of beginning psychosis (N=151) with a follow-up length of 60 months. At follow-up, the rate of conversion to schizophrenia spectrum diagnosis was 37%, whereas the conversion rate from schizotypal disorder to schizophrenia was 25%. High levels of perplexity and self-disorders baseline scores yielded the best prediction of the subsequent development of schizophrenia spectrum disorders. Escalating transitions within the spectrum (i.e., from schizotypal disorder to schizophrenia) were not associated to any candidate psychopathological predictor.     

Efficient production of cordycepin by the Cordyceps militaris mutant G81-3 for practical use

Cordycepin is one of the most versatile metabolites of Cordyceps militaris. When C. militaris G81-3, the mutant obtained by a proton beam irradiation, was cultivated by liquid surface culture, cordycepin was found to crystallize in the medium due to high cordycepin concentration. Because the cordycepin crystals strongly attached to the mycelial mat, complete recovery of cordycepin was difficult. To prevent cordycepin crystallization, increase of the initial medium volume was examined to decrease the condensation rate by vaporization, in combination with decrease of the initial substrate level. Besides, addition of the water to the culture bottle was examined to cancel out the medium condensation. A 7.4 g/L of cordycepin was obtained without crystallization by the former method. The upper limit of cordycepin production, 14.3 g/L, was obtained by the latter method and this value was the highest level of all the previous reports. A 2.5-fold scale-up of the culture slightly declined the production rate, however, the amount of cordycepin production was properly 2.5 times higher than that of the small scale. In addition, differences in sensitivities to the substrates between the mutant and the wild-type strain are discussed.