Sequence complexity of poly(A) RNA fromPhysarum polycephalum

Summary Poly(A) RNA from S phase, G₂ phase and starved macroplasmodia of Physarum contain mRNA sequences which when translated in vitro, yield similar patterns of polypeptides after fluorography.Reassociation of nick-translated DNA (Cot) allows the isolation of highly labeled single copy DNA which, after saturation hybridization with poly(A) RNA, gives values of 23% for growth and 17% for starvation.Homologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that 22–28% of the genome is transcribed during growth and 12% during starvation and that about half of the cDNA reacts with 0.1% of the genome and could represent 50–80 RNA species, each present in about 1,000 copies per nucleus. Up to 25,000 different RNA species, 1–5 copies each per nucleus, are estimated to be present during growth, and about 15,000 during starvation. Heterologous cDNA/poly(A) RNA hybridization reactions (Rot) indicate that the RNA sequences in S and G₂ phase of the cell cycle are similar, with RNA sequences being more abundant in G₂ phase.During starvation about 25% of the sequences present during growth cannot be detected and those sequences present during growth have become diluted during starvation.     

Lysophosphatidic Acid Acyltransferase from Coconut Endosperm Mediates the Insertion of Laurate at the sn-2 Position of Triacylglycerols in Lauric Rapeseed Oil and Can Increase Total Laurate Levels

Expression of a California bay laurel (Umbellularia californica) 12:0-acyl-carrier protein thioesterase, bay thioesterase (BTE), in developing seeds of oilseed rape (Brassica napus) led to the production of oils containing up to 50% laurate. In these BTE oils, laurate is found almost exclusively at the sn-1 and sn-3 positions of the triacylglycerols (T.A. Voelker, T.R. Hayes, A.C. Cranmer, H.M. Davies [1996] Plant J 9: 229–241). Coexpression of a coconut (Cocos nucifera) 12:0-coenzyme A-preferring lysophosphatitic acid acyltransferase (D.S. Knutzon, K.D. Lardizabal, J.S. Nelsen, J.L. Bleibaum, H.M. Davies, J.G. Metz [1995] Plant Physiol 109: 999–1006) in BTE oilseed rape seeds facilitates efficient laurate deposition at the sn-2 position, resulting in the acccumulation of trilaurin. The introduction of the coconut protein into BTE oilseed rape lines with laurate above 50 mol % further increases total laurate levels.     

Nuclei plug septal pores in severed hyphae of Sordaria brevicollis

Colonies of Sordaria brevicollis cut with a razor blade were examined and compared to undamaged control colonies using light and transmission electron microscopy. Cut hyphae lost cytoplasm from severed compartments but retained cytoplasm in adjacent compartments due to the plugging of septal pores by nuclei. Hexagonal crystals were observed in hyphae but were neither positioned near to septal pores nor observed plugging them. Approximately 36% of setpal pores in undamaged hyphae were found to contain a nucleus, presumably migrating through them. It is suggested that nuclei plug septal pores in severed hyphae of S. brevicollis because they are more conveniently positioned to do so than the distant hexagonal crystals.     

Neural activation and functional connectivity during motor imagery of bimanual everyday actions

Bimanual actions impose intermanual coordination demands not present during unimanual actions. We investigated the functional neuroanatomical correlates of these coordination demands in motor imagery (MI) of everyday actions using functional magnetic resonance imaging (fMRI). For this, 17 participants imagined unimanual actions with the left and right hand as well as bimanual actions while undergoing fMRI. A univariate fMRI analysis showed no reliable cortical activations specific to bimanual MI, indicating that intermanual coordination demands in MI are not associated with increased neural processing. A functional connectivity analysis based on psychophysiological interactions (PPI), however, revealed marked increases in connectivity between parietal and premotor areas within and between hemispheres. We conclude that in MI of everyday actions intermanual coordination demands are primarily met by changes in connectivity between areas and only moderately, if at all, by changes in the amount of neural activity. These results are the first characterization of the neuroanatomical correlates of bimanual coordination demands in MI. Our findings support the assumed equivalence of overt and imagined actions and highlight the differences between uni- and bimanual actions. The findings extent our understanding of the motor system and may aid the development of clinical neurorehabilitation approaches based on mental practice.     

Large-scale production of a therapeutic protein in transgenic tobacco plants: effect of subcellular targeting on quality of a recombinant dog gastric lipase

A recombinant dog gastric lipase with therapeutic potential for the treatment of exocrine pancreatic insufficiency was expressed in transgenic tobacco plants. We targeted the protein using two different signal sequences for either vacuolar retention or secretion. In both cases, an active glycosylated recombinant protein was obtained. The recombinant enzymes and the native enzyme displayed similar properties including acid resistance and acidic optimum pH. The proteolytic maturation and the specific activity of the recombinant proteins, however, were found to be dependent on subcellular compartmentalization. Expression levels of recombinant dog gastric lipase were about 5% and 7% of acid extractable plant proteins for vacuolar retention and secretion respectively. This expression system already has allowed the production of tens of grams of purified lipase through open-field culture of transgenic tobacco plants.     

Chilling outweighs photoperiod in preventing precocious spring development

It is well known that increased spring temperatures cause earlier onset dates of leaf unfolding and flowering. However, a temperature increase in winter may be associated with delayed development when species' chilling requirements are not fulfilled. Furthermore, photosensitivity is supposed to interfere with temperature triggers. To date, neither the relative importance nor possible interactions of these three factors have been elucidated. In this study, we present a multispecies climate chamber experiment to test the effects of chilling and photoperiod on the spring phenology of 36 woody species. Several hypotheses regarding their variation with species traits (successional strategy, floristic status, climate of their native range) were tested. Long photoperiods advanced budburst for one‐third of the studied species, but magnitudes of these effects were generally minor. In contrast to prior hypotheses, photosensitive responses were not restricted to climax or oceanic species. Increased chilling length advanced budburst for almost all species; its effect greatly exceeding that of photoperiod. Moreover, we suggest that photosensitivity and chilling effects have to be rigorously disentangled, as the response to photoperiod was restricted to individuals that had not been fully chilled. The results indicate that temperature requirements and successional strategy are linked, with climax species having higher chilling and forcing requirements than pioneer species. Temperature requirements of invasive species closely matched those of native species, suggesting that high phenological concordance is a prerequisite for successful establishment. Lack of chilling not only led to a considerable delay in budburst but also caused substantial changes in the chronological order of species' budburst. The results reveal that increased winter temperatures might impact forest ecosystems more than formerly assumed. Species with lower chilling requirements, such as pioneer or invasive species, might profit from warming winters, if late spring frost events would in parallel occur earlier.     

Response of severed Penicillium chrysogenum hyphae following rapid Woronin body plugging of septal pores

Colonies of Penicillium chrysogenum (Thom) Wisconsin strain Q176 were fixed at varying time intervals after having been severed with a razor blade and were examined by transmission electron microscopy. Within such colonies Woronin bodies were found to have plugged septal pores on either side of the cut, both towards and away from the hyphal apices. A very close association of Woronin bodies with septa was retained in damaged compartments emptied of virtually all other contents. In colonies fixed 3 h after cutting, deposition of material over the plugged pores occurred on the side of the septum away from the cut. The newly deposited material was similar in appearance to hyphal wall and septal plate constituents. This consolidation of the seal was apparently completed within 3 h because no further change was observed in colonies fixed 17 h after cutting.     

Evaluation of the Growth Assessment Protocol (GAP) for antenatal detection of small for gestational age: The DESiGN cluster randomised trial

BackgroundAntenatal detection and management of small for gestational age (SGA) is a strategy to reduce stillbirth. Large observational studies provide conflicting results on the effect of the Growth Assessment Protocol (GAP) in relation to detection of SGA and reduction of stillbirth; to the best of our knowledge, there are no reported randomised control trials. Our aim was to determine if GAP improves antenatal detection of SGA compared to standard care.Methods and findingsThis was a pragmatic, superiority, 2-arm, parallel group, open, cluster randomised control trial. Maternity units in England were eligible to participate in the study, except if they had already implemented GAP. All women who gave birth in participating clusters (maternity units) during the year prior to randomisation and during the trial (November 2016 to February 2019) were included. Multiple pregnancies, fetal abnormalities or births before 24⁺¹ weeks were excluded. Clusters were randomised to immediate implementation of GAP, an antenatal care package aimed at improving detection of SGA as a means to reduce the rate of stillbirth, or to standard care. Randomisation by random permutation was stratified by time of study inclusion and cluster size. Data were obtained from hospital electronic records for 12 months prerandomisation, the washout period (interval between randomisation and data collection of outcomes), and the outcome period (last 6 months of the study). The primary outcome was ultrasound detection of SGA (estimated fetal weight <10th centile using customised centiles (intervention) or Hadlock centiles (standard care)) confirmed at birth (birthweight <10th centile by both customised and population centiles). Secondary outcomes were maternal and neonatal outcomes, including induction of labour, gestational age at delivery, mode of birth, neonatal morbidity, and stillbirth/perinatal mortality. A 2-stage cluster–summary statistical approach calculated the absolute difference (intervention minus standard care arm) adjusted using the prerandomisation estimate, maternal age, ethnicity, parity, and randomisation strata. Intervention arm clusters that made no attempt to implement GAP were excluded in modified intention to treat (mITT) analysis; full ITT was also reported. Process evaluation assessed implementation fidelity, reach, dose, acceptability, and feasibility. Seven clusters were randomised to GAP and 6 to standard care. Following exclusions, there were 11,096 births exposed to the intervention (5 clusters) and 13,810 exposed to standard care (6 clusters) during the outcome period (mITT analysis). Age, height, and weight were broadly similar between arms, but there were fewer women: of white ethnicity (56.2% versus 62.7%), and in the least deprived quintile of the Index of Multiple Deprivation (7.5% versus 16.5%) in the intervention arm during the outcome period. Antenatal detection of SGA was 25.9% in the intervention and 27.7% in the standard care arm (adjusted difference 2.2%, 95% confidence interval (CI) −6.4% to 10.7%; p = 0.62). Findings were consistent in full ITT analysis. Fidelity and dose of GAP implementation were variable, while a high proportion (88.7%) of women were reached. Use of routinely collected data is both a strength (cost-efficient) and a limitation (occurrence of missing data); the modest number of clusters limits our ability to study small effect sizes.ConclusionsIn this study, we observed no effect of GAP on antenatal detection of SGA compared to standard care. Given variable implementation observed, future studies should incorporate standardised implementation outcomes such as those reported here to determine generalisability of our findings.Trial registrationThis trial is registered with the ISRCTN registry, ISRCTN67698474.

Matias C Vieira and colleagues evaluate the Growth Assessment Protocol (GAP) for antenatal detection of small for gestational age in the DESiGN cluster randomised trial.     

The Burden of Research on Trauma for Respondents: A Prospective and Comparative Study on Respondents Evaluations and Predictors

The possible burden of participating in trauma research is an important topic for Ethical Committees (EC''s), Review Boards (RB''s) and researchers. However, to what extent research on trauma is more burdensome than non-trauma research is unknown. Little is known about which factors explain respondents evaluations on the burden: to what extent are they trauma-related or dependent on other factors such as personality and how respondents evaluate research in general? Data of a large probability based multi-wave internet panel, with surveys on politics and values, personality and health in 2009 and 2011, and a survey on trauma in 2012 provided the unique opportunity to address these questions. Results among respondents confronted with these events in the past 2 years (N = 950) showed that questions on trauma were significantly and systematically evaluated as less pleasant (enjoyed less), more difficult, but also stimulated respondents to think about things more than almost all previous non-trauma surveys. Yet, the computed effect sizes indicated that the differences were (very) small and often meaningless. No differences were found between users and non-users of mental services, in contrast to posttraumatic stress symptoms. Evaluations of the burden of previous surveys in 2011 on politics and values, personality and health most strongly, systematically and independently predicted the burden of questions on trauma, and not posttraumatic stress symptoms, event-related coping self-efficacy and personality factors. For instance, multiple linear regression analyses showed that 30% of the variance of how (un)pleasant questions on trauma and life-events were evaluated, was explained by how (un)pleasant the 3 surveys in 2011 were evaluated, in contrast to posttraumatic stress symptoms (not significant) and coping self-efficacy (5%). Findings question why EC''s, RB''s and researchers should be more critical of the possible burden of trauma research than of the possible burden of other non-trauma research.     

Blood–Brain Transfer of Glucose and Glucose Analogs in Newborn Rats

Little is known of the selectivity of the blood-brain barrier at birth. Hexoses are transported through the barrier by a facilitating mechanism. To study the capacity of this mechanism to distinguish between analogs of D-glucose, we compared the transport of fluorodeoxyglucose, deoxyglucose, glucose, methylglucose, mannose, galactose, mannitol, and iodoantipyrine across the cerebral capillary endothelium in newborn Wistar rats. Cerebral blood flow, glucose consumption, and the blood-brain permeabilities of the hexoses were 25-50% of the adult values but the ratios between the permeabilities of the individual hexoses were similar to the ratios observed in adult rats. The mannitol clearance into brain was considerably higher than in adult rats (about 10-fold), indicating a higher endothelial permeability to small polar nonelectrolytes. The brain water content was higher in newborn than in adult rats and was associated with a higher steady-state distribution of labeled methylglucose between brain and blood. Hexose concentrations were determined relative to whole blood because the apparent erythrocyte membrane permeability to glucose was as high as in humans and thus considerably higher than in adult rats. The half-saturation concentration of glucose transport across the blood-brain barrier was considerably higher than in adult rats, about three-fold, suggesting that net blood-brain glucose transfer is less sensitive to blood glucose fluctuation in newborn than in adult rats.