Local ciliate communities associated with aquatic macrophytes

This study, based within the catchment area of the River Frome, an important chalk stream in the south of England, compared ciliated protozoan communities associated with three species of aquatic macrophyte common to lotic habitats: Ranunculus penicillatus subsp. pseudofluitans, Nasturtium officinale and Sparganium emersum. A total of 77 ciliate species were counted. No species-specific ciliate assemblage was found to be typical of any one plant species. Ciliate abundance between plant species was determined to be significantly different. The ciliate communities from each plant species were unique in that the number of species increased with ciliate abundance. The community associated with R. penicillatus subsp. pseudofluitans showed the highest consistency and species richness whereas S. emersum ciliate communities were unstable. Most notably, N. officinale was associated with low ciliate abundances and an apparent reduction in biofilm formation, discussed herein in relation to the plant’s production of the microbial toxin phenethyl isothiocyanate. We propose that the results reflect differences in the quantity and quality of biofilm present on the plants, which could be determined by the different plant morphologies, patterns of plant decay and herbivore defense systems, all of which suppress or promote the various conditions for biofilm growth. [Int Microbiol 2014; 17(1):31-40]Keywords: Ranunculus · Nasturtium · toxin phenethyl isothiocyanate (PEITC) · biofilms · macrophytes · ciliates · microbial biodiversit

The physiology of alien chloroplasts: light adaptation mechanisms in cytoplasmic hybrids of the Solanaceae family.

PhDThe investigation presented here is of a new plant model for photosynthesis research. The plant's novelty is a hybrid cytoplasm which was engineered to contain the nuclear genome of Nicotiana tabacum (tobacco) and the chloroplast genome of Hyoscyamus niger (henbane). For photosynthesis research the implications of cytoplasmic hybridisation centre on the nuclear and chloroplast encoded pigment protein complexes of the photosynthetic machinery in the thylakoid membrane of the chloroplast. We investigate how the energy input from nuclear-encoded light harvesting complexes to the chloroplast-encoded core complexes is regulated in the cybrid plants, when light limits or exceeds photochemical capacity. When light limited, the phenomenon of state transitions (ST) serves to redress the imbalance of light input at PSI and PSII. In excess light, non-photochemical quenching (NPQ) mechanisms are activated in order to safely dissipate potentially harmful energy that has been absorbed by the system. Our investigation at first indicated that the cybrid plants had a greater capacity for NPQ compared to wildtype N. tabacum and H. niger. LHCII aggregation, xanthopyll cycle activity and PsbS were investigated for a possible reasons for the increase. However no difference or contradictory evidence was found. NPQ measurements were repeated and showed large variability and no significant difference in NPQ capacity compared to the wildtype parent species. The reason for the variability in the cybrid results could not be resolved but is suggested to be due to heightened environmental sensitivity. STs were found to be consistently inhibited in cybrids. Investigation of cybrid LHC isoelectric points and molecular weight revealed novelties. LHCs were then subjected to proteomic analysis that indicated possible truncation at the N-terminus, and thus the possible removal of a phosphorylation site that crucial for the initiation of ST. We also investigate the ability of the Nt(Hn) cybrid to adjust to high and low intensity light environments in terms of acclimation at the level of the whole plant, leaf, tissue, cell, chloroplast, thylakoid membrane, pigment, and electron transport rates.BBSR

Drivers of inter-year variability of plant production and decomposers across contrasting island ecosystems

Despite the likely importance of inter-year dynamics of plant production and consumer biota for driving community- and ecosystem-level processes, very few studies have explored how and why these dynamics vary across contrasting ecosystems. We utilized a well characterized system of 30 lake islands in the boreal forest zone of northern Sweden across which soil fertility and productivity vary considerably, with larger islands being more fertile and productive than smaller ones. In this system we assessed the inter-year dynamics of several measures of plant production and the soil microbial community (primary consumers in the decomposer food web) for each of 9 years, and soil microfaunal groups (secondary and tertiary consumers) for each of 6 of those years. We found that for measures of plant production and each of the three consumer trophic levels, inter-year dynamics were strongly affected by island size. Further, many variables were strongly affected by island size (and thus bottom-up regulation by soil fertility and resources) for some years but none in others, most likely due to inter-year variation in climatic conditions. For each of the plant and microbial variables for which we had 9 years of data, we also determined the inter-year coefficient of variation (CV), an inverse measure of stability. We found that CVs of some measures of plant productivity were greater on large islands while those of other measures were greater on smaller islands; CVs of microbial variables were unresponsive to island7 size. We also found that the effects of island size on the temporal dynamics of some variables were related to inter-year variability of macroclimatic variables. As such, our results show that the inter year dynamics of both plant productivity and decomposer biota across each of three trophic levels, as well as the inter-year stability of plant productivity, differs greatly across contrasting ecosystems, with potentially important but largely overlooked implications for community and ecosystem processes

The Bangor Gambling Task: Characterising the performance of survivors of traumatic brain injury

The Bangor Gambling Task (BGT, Bowman & Turnbull, 2004) is a simple test of emotion-based decision-making, with contingencies varying across five blocks of 20 trials. This is the first study to characterise BGT performance in survivors of traumatic brain injury (TBI) relative to healthy controls. The study also aimed to explore sub-groups (cluster analysis), and identify predictors of task performance (multiple regression). Thirty survivors of TBI and 39 controls completed the BGT and measures of premorbid IQ, working memory, and executive function. Results showed that survivors of TBI made more gamble choices than controls (total BGT score), although the groups did not significantly differ when using a cut-off score for ‘impaired’ performance. Unexpectedly, the groups did not significantly differ in their performance across the blocks, however, the cluster analysis revealed three subgroups (with survivors of TBI and controls represented in each cluster). Findings also indicated that age and group were significant predictors of overall BGT performance, but not gender, premorbid IQ, or working memory and executive function. In conclusion, the study findings are consistent with an individual differences account of emotion-based decision-making, and a number of issues need to be addressed prior to recommending the clinical use of the BGT

Absence of photosynthetic state transitions in alien chloroplasts

MAIN CONCLUSION:The absence of state transitions in a Nt(Hn) cybrid is due to a cleavage of the threonine residue from the misprocessed N-terminus of the LHCII polypeptides. The cooperation between the nucleus and chloroplast genomes is essential for plant photosynthetic fitness. The rapid and specific interactions between nucleus-encoded and chloroplast-encoded proteins are under intense investigation with potential for applications in agriculture and renewable energy technology. Here, we present a novel model for photosynthesis research in which alien henbane (Hyoscyamus niger) chloroplasts function on the nuclear background of a tobacco (Nicotiana tabacum). The result of this coupling is a cytoplasmic hybrid (cybrid) with inhibited state transitions-a mechanism responsible for balancing energy absorption between photosystems. Protein analysis showed differences in the LHCII composition of the cybrid plants. SDS-PAGE analysis revealed a novel banding pattern in the cybrids with at least one additional 'LHCII' band compared to the wild-type parental species. Proteomic work suggested that the N-terminus of at least some of the cybrid Lhcb proteins was missing. These findings provide a mechanistic explanation for the lack of state transitions-the N-terminal truncation of the Lhcb proteins in the cybrid included the threonine residue that is phosphorylated/dephosphorylated in order to trigger state transitions and therefore crucial energy balancing mechanism in plants

Predictors of Long-Term Victimization After Early Pediatric Traumatic Brain Injury

Pediatric traumatic brain injuries (TBIs) adversely affect long-term functional and social outcomes. Limited research suggests children with TBI are more likely to be victimized by peers than noninjured children. Deficits in social information processing (SIP), cognitive ability, and executive functioning (EF) may contribute to increased victimization risk. This study examined rates of peer victimization/bullying in children with early TBI compared with children with orthopedic injuries (OIs) and the role of processing speed, executive function (EF), and SIP as mediators of the association of TBI and peer victimization

Associations between maternal thyroid function in pregnancy and child neurodevelopmental outcomes at 20 months in the Seychelles Child Development Study, Nutrition Cohort 2 (SCDS NC2)

Maternal thyroid hormones facilitate optimal foetal neurodevelopment; however, the exact role of the thyroid hormones on specific cognitive outcomes is unknown. The present study aimed to investigate associations between maternal thyroid function and neurodevelopmental outcomes in the Seychelles Child Development Study (SCDS) Nutrition 2 cohort (n 1328). Maternal free thyroid hormones (fT3, fT4 and fTSH) were assessed at 28 weeks’ gestation with a range of child cognitive outcomes analysed at 20 months. Dietary iodine intake was analysed for a subset of women through a Food Frequency Questionnaire. Linear regression analysis was used to test associations between serum concentrations of maternal thyroid hormones and child neurodevelopment outcomes. Thyroid hormones were analysed as continuous data and categorised as quintiles. 95% of mothers had optimal thyroid function based on fTSH concentrations. Overall, the present study shows that maternal thyroid function is not associated with neurodevelopmental outcomes in this high fish-eating population. However, a positive association, using quintiles for fT3, was reported for the Mental Developmental Index, between Q3 v. Q4 (β 0⋅073; P 0⋅043) and for Q3 v. Q5 (β value 0⋅086; P 0⋅018). To conclude, mothers in our cohort, who largely have optimal thyroid function and iodine intakes, appear able to regulate thyroid function throughout pregnancy to meet neurodevelopmental needs. However, it is possible that minor imbalances of fT3, as indicated from our secondary analysis, may impact offspring neurodevelopment. Further investigation of the relationship between maternal thyroid function and infant neurodevelopment is warranted, particularly in populations with different dietary patterns and thereby iodine intakes

Early pushing urge in labour and midwifery practice: A prospective observational study at an Italian maternity hospital

OBJECTIVE: to investigate the early pushing urge (EPU) incidence in one maternity unit and explore how it is managed by midwives. The relation to some obstetric outcomes was also observed but not analysed in depth. DESIGN: prospective observational study. SETTING: Italian maternity hospital. SAMPLE: 60 women (44 nullips and 16 multips) experiencing EPU during labour. FINDINGS: the total EPU incidence percentage was 7.6%. The single midwives’ incidences range had a very wide margin, noting an inverse proportion between the number of diagnoses of EPU and midwife’s waiting time between urge to push and vaginal examination. Two care policies were adopted in relation to the phenomenon: the stop pushing technique (n¼52/60) and the ‘let the woman do what she feels’ technique (n¼8/60). In case of stop pushing techniques, midwives proposed several combined techniques (change of maternal position, blowing breath, vocalisation, use of the bath). The EPU diagnosis at less than 8 cm of cervical dilatation was associated with more medical interventions. Maternal and neonatal outcomes were within the range of normal physiology. An association between the dilatation at EPU diagnosis and obstetric outcomes was observed, in particular the modality of childbirth and perineal outcomes. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: this paper contributes new knowledge to the body of literature around the EPU phenomenon during labour and midwifery practices adopted in response to it. Overall, it could be argued that EPU is a physiologic variation in labour if maternal and fetal conditions are good. Midwives might suggest techniques to woman to help her to stay with the pain, such as change of position, blowing breath, vocalisation and use of the bath. However, the impact of policies, guidelines and culture on midwifery practices of the specific setting are a limitation of the study because it is not representative of other similar maternity units. Thus, a larger scale work should be considered, including different units and settings. The optimal response to the phenomenon should be studied, considering EPU at different dilatation ranges. Future investigations could also focus on qualitative analysis of women and midwives’ personal experience in relation to the phenomenon

Dr. Godfrey Mbaruku: A tribute and review of the life of a maternal health crusader in Tanzania

Dr. Godfrey Mbaruku, an obstetrician-gynecologist and one of Tanzania’s most dedicated maternal health researchers, passed away in September 2018. His professional career spanned over four decades, with the last decade of his life dedicated to maternal health research, advocacy and policy in Africa. We undertook a review of the key global milestones in maternal health policy, funding and research that took place during Dr. Mbaruku’s career until his untimely death in 2018. We then reflect on the progress of the maternal health agenda from 2018 to 2021 as lower middle income countries (LMICs) continue to strive to reach the sustainable development goals (SDGs) in the midst of a global pandemic. Dr. Godfrey Mbaruku’s commitment to improving maternal health in Tanzania through his advocacy and research contributions over his professional life will forever serve as foundational pillars for the ongoing global effort to reduce maternal mortality.   Le Dr Godfrey Mbaruku, obstétricien-gynécologue et l'un des chercheurs en santé maternelle les plus dévoués de Tanzanie, est décédé en septembre 2018. Sa carrière professionnelle a duré plus de quatre décennies, la dernière décennie de sa vie étant consacrée à la recherche, au plaidoyer et aux politiques en santé maternelle en Afrique. Nous avons entrepris un examen des principales étapes mondiales de la politique, du financement et de la recherche en matière de santé maternelle qui ont eu lieu au cours de la carrière du Dr Mbaruku jusqu'à sa mort prématurée en 2018. Nous réfléchissons ensuite aux progrès du programme de santé maternelle de 2018 à 2021 en tant que milieu inférieur. Les pays à revenu intermédiaire (PRFI) continuent de s'efforcer d'atteindre les objectifs de développement durable (ODD) au milieu d'une pandémie mondiale. L'engagement du Dr Godfrey Mbaruku à améliorer la santé maternelle en Tanzanie grâce à ses contributions de plaidoyer et de recherche au cours de sa vie professionnelle servira à jamais de piliers fondamentaux pour l'effort mondial en cours pour réduire la mortalité maternelle

Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle

International audienceAbstractBackgroundWhite spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein–Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein–Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date.ResultsUsing imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region.ConclusionsOur findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics