1,020 research outputs found
Multispecies diel transcriptional oscillations in open ocean heterotrophic bacterial assemblages
Oscillating diurnal rhythms of gene transcription, metabolic activity, and behavior are found in all three domains of life. However, diel cycles in naturally occurring heterotrophic bacteria and archaea have rarely been observed. Here, we report time-resolved whole-genome transcriptome profiles of multiple, naturally occurring oceanic bacterial populations sampled in situ over 3 days. As anticipated, the cyanobacterial transcriptome exhibited pronounced diel periodicity. Unexpectedly, several different heterotrophic bacterioplankton groups also displayed diel cycling in many of their gene transcripts. Furthermore, diel oscillations in different heterotrophic bacterial groups suggested population-specific timing of peak transcript expression in a variety of metabolic gene suites. These staggered multispecies waves of diel gene transcription may influence both the tempo and the mode of matter and energy transformation in the sea.Gordon and Betty Moore Foundation (GBMF 492.01)Gordon and Betty Moore Foundation (GBMF 3777)National Science Foundation (U.S.) (Grant EF0424599)David & Lucile Packard Foundatio
Ultrabithorax confers spatial identity in a context-specific manner in the Drosophila postembryonic ventral nervous system.
BACKGROUND: In holometabolous insects such as Drosophila melanogaster, neuroblasts produce an initial population of diverse neurons during embryogenesis and a much larger set of adult-specific neurons during larval life. In the ventral CNS, many of these secondary neuronal lineages differ significantly from one body segment to another, suggesting a role for anteroposterior patterning genes. RESULTS: Here we systematically characterize the expression pattern and function of the Hox gene Ultrabithorax (Ubx) in all 25 postembryonic lineages. We find that Ubx is expressed in a segment-, lineage-, and hemilineage-specific manner in the thoracic and anterior abdominal segments. When Ubx is removed from neuroblasts via mitotic recombination, neurons in these segments exhibit the morphologies and survival patterns of their anterior thoracic counterparts. Conversely, when Ubx is ectopically expressed in anterior thoracic segments, neurons exhibit complementary posterior transformation phenotypes. CONCLUSION: Our findings demonstrate that Ubx plays a critical role in conferring segment-appropriate morphology and survival on individual neurons in the adult-specific ventral CNS. Moreover, while always conferring spatial identity in some sense, Ubx has been co-opted during evolution for distinct and even opposite functions in different neuronal hemilineages
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Update to the effectiveness and cost-effectiveness of a mindfulness training programme in schools compared with normal school provision (MYRIAD): study protocol for a randomised controlled trial.
BACKGROUND: MYRIAD (My Resilience in Adolescence) is a superiority, parallel group, cluster randomised controlled trial designed to examine the effectiveness and cost-effectiveness of a mindfulness training (MT) programme, compared with normal social and emotional learning (SEL) school provision to enhance mental health, social-emotional-behavioural functioning and well-being in adolescence. The original trial protocol was published in Trials (accessible at https://doi.org/10.1186/s13063-017-1917-4 ). This included recruitment in two cohorts, enabling the learning from the smaller first cohort to be incorporated in the second cohort. Here we describe final amendments to the study protocol and discuss their underlying rationale. METHODS: Four major changes were introduced into the study protocol: (1) there were changes in eligibility criteria, including a clearer operational definition to assess the degree of SEL implementation in schools, and also new criteria to avoid experimental contamination; (2) the number of schools and pupils that had to be recruited was increased based on what we learned in the first cohort; (3) some changes were made to the secondary outcome measures to improve their validity and ability to measure constructs of interest and to reduce the burden on school staff; and (4) the current Coronavirus Disease 2019 (SARS-CoV-2 or COVID-19) pandemic both influences and makes it difficult to interpret the 2-year follow-up primary endpoint results, so we changed our primary endpoint to 1-year follow-up. DISCUSSION: These changes to the study protocol were approved by the Trial Management Group, Trial Steering Committee and Data and Ethics Monitoring Committees and improved the enrolment of participants and quality of measures. Furthermore, the change in the primary endpoint will give a more reliable answer to our primary question because it was collected prior to the COVID-19 pandemic in both cohort 1 and cohort 2. Nevertheless, the longer 2-year follow-up data will still be acquired, although this time-point will be now framed as a second major investigation to answer some new important questions presented by the combination of the pandemic and our study design. TRIAL REGISTRATION: International Standard Randomised Controlled Trials ISRCTN86619085 . Registered on 3 June 2016
Love in the Time of COVID-19: Negligence in the Nicaraguan Response
The response of the Nicaraguan government to the coronavirus disease 2019 (COVID-19) pandemic has been perhaps the most erratic of any country in the world to date. Directly contradicting mitigation strategies recommended by WHO, President Daniel Ortega has refused to encourage any physical distancing measures. Vice President Rosario Murillo (Daniel Ortega\u27s wife) instead called on thousands of sympathisers to congregate in street marches under the slogan \u27love in the time of COVID-19\u27. By downplaying the danger of the pandemic and increasing the risk of community transmission in the second-poorest country in the western hemisphere, the Nicaraguan government is violating the human rights of its citizens
Plasma metabolomics and clinical predictors of survival differences in COPD patients
Background: Plasma metabolomics profile (PMP) in COPD has been associated with clinical characteristics, but PMP’s relationship to survival has not been reported. We determined PMP differences between patients with COPD who died an average of 2 years after enrollment (Non-survivors, NS) compared to those who survived (S) and also with age matched controls (C).
Methods: We studied prospectively 90 patients with severe COPD and 30 controls. NS were divided in discovery and validation cohorts (30 patients each) and the results compared to the PMP of 30 S and C. All participants completed lung function tests, dyspnea scores, quality of life, exercise capacity, BODE index, and plasma metabolomics by liquid and gas chromatography / mass spectometry (LC/MS, LC/MS2 , GC/MS). Statistically, we used Random Forest Analysis (RFA) and Support Vector Machine (SVM) to determine metabolites that differentiated the 3 groups and compared the ability of metabolites vs. clinical characteristics to classify patients into survivors and non-survivors.
Results: There were 79 metabolites statistically different between S and NS [p < 0.05 and false discovery rate (q value) < 0.1]. RFA and SVM classification of COPD survivors and non-survivors had a predicted accuracy of 74 and 85% respectively. Elevation of tricyclic acid cycle intermediates branched amino acids depletion and increase in lactate, fructose and xylonate showed the most relevant differences between S vs. NS suggesting alteration in mitochondrial oxidative energy generation. PMP had similar predictive power for risk of death as information provided by clinical characteristics.
Conclusions: A plasma metabolomic profile characterized by an oxidative energy production difference between survivors and non-survivors was observed in COPD patients 2 years before death
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Connectomics Analysis Reveals First-, Second-, and Third-Order Thermosensory and Hygrosensory Neurons in the Adult Drosophila Brain.
Animals exhibit innate and learned preferences for temperature and humidity-conditions critical for their survival and reproduction. Leveraging a whole-brain electron microscopy volume, we studied the adult Drosophila melanogaster circuitry associated with antennal thermo- and hygrosensory neurons. We have identified two new target glomeruli in the antennal lobe, in addition to the five known ones, and the ventroposterior projection neurons (VP PNs) that relay thermo- and hygrosensory information to higher brain centers, including the mushroom body and lateral horn, seats of learned and innate behavior. We present the first connectome of a thermo- and hygrosensory neuropil, the lateral accessory calyx (lACA), by reconstructing neurons downstream of heating- and cooling-responsive VP PNs. A few mushroom body-intrinsic neurons solely receive thermosensory input from the lACA, while most receive additional olfactory and thermo- and/or hygrosensory PN inputs. Furthermore, several classes of lACA-associated neurons form a local network with outputs to other brain neuropils, suggesting that the lACA serves as a hub for thermo- and hygrosensory circuitry. For example, DN1a neurons link thermosensory PNs in the lACA to the circadian clock via the accessory medulla. Finally, we survey strongly connected downstream partners of VP PNs across the protocerebrum; these include a descending neuron targeted by dry-responsive VP PNs, meaning that just two synapses might separate hygrosensory inputs from motor circuits. These data provide a comprehensive first- and second-order layer analysis of Drosophila thermo- and hygrosensory systems and an initial survey of third-order neurons that could directly modulate behavior.MRC LMB Graduate Studentship to M.W.P.
Boehringer Ingelheim Fonds PhD Fellowship and a Herchel Smith Studentship to A.S.B.
Cambridge Neuroscience-PSL collaborative grant supported by the Embassy of France in London to G.S.X.E.J
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Pathways to Coastal Resiliency: The Adaptive Gradients Framework
Current and future climate-related coastal impacts such as catastrophic and repetitive flooding, hurricane intensity, and sea level rise necessitate a new approach to developing and managing coastal infrastructure. Traditional “hard” or “grey” engineering solutions are proving both expensive and inflexible in the face of a rapidly changing coastal environment. Hybrid solutions that incorporate natural, nature-based, structural, and non-structural features may better achieve a broad set of goals such as ecological enhancement, long-term adaptation, and social benefits, but broad consideration and uptake of these approaches has been slow. One barrier to the widespread implementation of hybrid solutions is the lack of a relatively quick but holistic evaluation framework that places these broader environmental and societal goals on equal footing with the more traditional goal of exposure reduction. To respond to this need, the Adaptive Gradients Framework was developed and pilot-tested as a qualitative, flexible, and collaborative process guide for organizations to understand, evaluate, and potentially select more diverse kinds of infrastructural responses. These responses would ideally include natural, nature-based, and regulatory/cultural approaches, as well as hybrid designs combining multiple approaches. It enables rapid expert review of project designs based on eight metrics called “gradients”, which include exposure reduction, cost efficiency, institutional capacity, ecological enhancement, adaptation over time, greenhouse gas reduction, participatory process, and social benefits. The framework was conceptualized and developed in three phases: relevant factors and barriers were collected from practitioners and experts by survey; these factors were ranked by importance and used to develop the initial framework; several case studies were iteratively evaluated using this technique; and the framework was finalized for implementation. The article presents the framework and a pilot test of its application, along with resources that would enable wider application of the framework by practitioners and theorists
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The connectome of the adult Drosophila mushroom body provides insights into function.
Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit in Drosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work
Structured inquiry-based learning: Drosophila GAL4 enhancer trap characterization in an undergraduate laboratory course.
We have developed and tested two linked but separable structured inquiry exercises using a set of Drosophila melanogaster GAL4 enhancer trap strains for an upper-level undergraduate laboratory methods course at Bucknell University. In the first, students learn to perform inverse PCR to identify the genomic location of the GAL4 insertion, using FlyBase to identify flanking sequences and the primary literature to synthesize current knowledge regarding the nearest gene. In the second, we cross each GAL4 strain to a UAS-CD8-GFP reporter strain, and students perform whole mount CNS dissection, immunohistochemistry, confocal imaging, and analysis of developmental expression patterns. We have found these exercises to be very effective in teaching the uses and limitations of PCR and antibody-based techniques as well as critical reading of the primary literature and scientific writing. Students appreciate the opportunity to apply what they learn by generating novel data of use to the wider research community
The connectome of the adult Drosophila mushroom body provides insights into function
Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit in Drosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work
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