bluuebunny/crossref_metadata_2025_split huggingface dataset:
Outer membrane-deprived cyanobacteria liberate periplasmic and thylakoid luminal components that support the growth of heterotrophs
Authors: Kojima Seiji , Okumura Yasuaki 
Published: March 2020

ABSTRACTChloroplasts originate from endosymbiosis of a cyanobacterium within a heterotrophic host cell. Establishing endosymbiosis requires the translocation across its envelope of photosynthetic products generated inside the once free-living cyanobacterium to be exploited by host metabolism. However, the nature of this translocation event is unknown. We previously found that most cyanobacterial outer membrane components were eliminated during the primitive stage of chloroplast evolution, suggesting the importance of evolutionary changes of the outer membrane. Here, we removed the outer membrane fromSynechocystissp. PCC 6803 by disrupting the physical interaction with peptidoglycan, and characterized the effects on cell function. Outer membrane-deprived cells liberated diverse substances into the environment without significantly compromising photoautotrophic growth. The amount of liberated proteins increased to ~0.35 g/L within five days of culture. Proteomic analysis showed that most liberated proteins were periplasmic and thylakoid luminal components. Connectivity between the thylakoid lumen-extracellular space was confirmed by findings that an exogenous hydrophilic oxidant was reduced by photosynthetic electron transport chain on the thylakoid membrane. Metabolomic analysis detected the release of nucleotide-related metabolites at concentrations around 1 μM. The liberated materials supported the proliferation of heterotrophic bacteria. These findings show that breaching the outer membrane, without any manipulations to the cytoplasmic membrane, converts a cyanobacterium to a chloroplast-like organism that conducts photosynthesis and releases its biogenic materials. This conversion not only represents a potential explanation why the outer membrane markedly changed during the earliest stage of chloroplast evolution, but also provides the opportunity to harness cyanobacterial photosynthesis for biomanufacturing processes.SIGNIFICANCE STATEMENTAlthough it is well accepted that chloroplasts stem from endosymbiosis of a cyanobacterium within a heterotrophic host cell, the issue of how photosynthetic products generated inside a formerly free-living cyanobacterium are translocated across its envelope and exploited by host metabolism has been little addressed. Here we show that breaching the cyanobacterial outer membrane barrier converts a cyanobacterium to a chloroplast-like organism that conducts photosynthesis and releases its diverse biogenic materials into its external environment, which sustains the growth of heterotrophic organisms. This conversion represents a possible example of metabolic exploitation of cyanobacterial photosynthesis. Further, this “quasi-chloroplast” provides a potential opportunity for industrial application such as producing feedstock for biomanufacturing processes that harnesses heterotrophic bacteria.
Moving-average based index to timely evaluate the current epidemic situation after COVID-19 outbreak
Authors: Yun-ting He , Xiao-jin Wang , Hao He , Jing Zhai , Bing-shun Wang 
Published: March 2020

[ABSTRACT]A pneumonia outbreak caused by a novel coronavirus (COVID-19) occurred in Wuhan, China at the end of 2019 and then spread rapidly to the whole country. A total of 81,498 laboratory-confirmed cases, including 3,267 deaths (4.0%) had been reported in China by March 22, 2020, meanwhile, 210,644 laboratory-confirmed cases and 9,517 deaths (4.5%) were reported outside China. Common symptoms of COVID-19 pneumonia included fever, fatigue and dry cough. In face of such a sudden outbreak of emerging novel infectious diseases, we have no history to learn from and no evidence to count on. Traditional models often predict inconsistent results. There is an urgent need to establish a practical data-driven method to predict the evolutionary trend of the epidemic, track and prejudge the current epidemic situation after the COVID-19 outbreak. Here we propose a simple, directly and generally applicable index and we name it ‘epidemic evaluation index’ (EEI), which is constructed by 7-day moving average of the log-transformed daily new cases (LMA). EEI could be used to support the decision-making process and epidemic prevention and control strategies through the evaluation of the current epidemic situation. First, we used SARS epidemic data from Hong Kong in 2003 to verify the practicability of the new index, which shows that the index is acceptable. The EEI was then applied to the COVID-19 epidemic situation analysis. We found that the trend direction of different districts in China changed on different date during the epidemic. At the national level and at local Hubei Province level, the epidemic both peaked on February 9. While the peak occurred relatively earlier, i.e. on February 5 in other provinces. It demonstrated the effectiveness of decisive action and implementations of control measures made by Chinese governments. While local governments should adjust management measures based on local epidemic situation. Although the epidemic has eased since late February, continued efforts in epidemic control are still required to prevent transmission of imported cases in China. However, the global COVID-19 epidemic outside China continues to expand as indicated by the EEI we proposed. Currently, efforts have been made worldwide to combat the novel coronavirus pandemic. People all over the world should work together and governments of all countries should take efficient measures in the light of Chinas experience and according to national circumstances and local conditions.
One size does not fit all. Genomics differentiates among binge-eating disorder, bulimia nervosa, and anorexia nervosa
Authors: Hübel Christopher , Abdulkadir Mohamed , Herle Moritz , Loos Ruth J.F. , Breen Gerome , Bulik Cynthia M. , Micali Nadia 
Published: March 2020

AbstractObjectiveGenome-wide association studies have identified multiple genomic regions associated with anorexia nervosa. Relatively few or no genome-wide studies of other eating disorders, such as bulimia nervosa and binge-eating disorder, have been performed, despite their substantial heritability. Exploratively, we aimed to identify traits that are genetically associated with binge-type eating disorders.MethodWe calculated genome-wide polygenic scores for 269 trait and disease outcomes using PRSice v2.2 and their association with anorexia nervosa, bulimia nervosa, and binge-eating disorder in up to 640 cases and 17,050 controls from the UK Biobank. Significant associations were tested for replication in the Avon Longitudinal Study of Parents and Children (up to 217 cases and 3018 controls).ResultsIndividuals with binge-type eating disorders had higher polygenic scores than controls for other psychiatric disorders, including depression, schizophrenia, and attention deficit hyperactivity disorder, and higher polygenic scores for body mass index.DiscussionOur findings replicate some of the known comorbidities of eating disorders on a genomic level and motivate a deeper investigation of shared and unique genomic factors across the three primary eating disorders.
Mathematical modeling of COVID-19 transmission and mitigation strategies in the population of Ontario, Canada
Authors: Tuite Ashleigh R. , Fisman David N. , Greer Amy L. 
Published: March 2020

AbstractBackgroundWe evaluated how non-pharmaceutical interventions could be used to control the COVID-19 pandemic and reduce the burden on the healthcare system.MethodsUsing an age-structured compartmental model of COVID-19 transmission in the population of Ontario, Canada, we compared a base case with limited testing, isolation, and quarantine to scenarios with: enhanced case finding; restrictive social distancing measures; or a combination of enhanced case finding and less restrictive social distancing. Interventions were either implemented for fixed durations or dynamically cycled on and off, based on projected ICU bed occupancy. We present median and credible intervals (CrI) from 100 replicates per scenario using a two-year time horizon.ResultsWe estimated that 56% (95% CrI: 42-63%) of the Ontario population would be infected over the course of the epidemic in the base case. At the epidemic peak, we projected 107,000 (95% CrI: 60,760-149,000) cases in hospital and 55,500 (95% CrI: 32,700-75,200) cases in ICU. For fixed duration scenarios, all interventions were projected to delay and reduce the height of the epidemic peak relative to the base case, with restrictive social distancing estimated to have the greatest effect. Longer duration interventions were more effective. Dynamic interventions were projected to reduce the proportion of the population infected at the end of the two-year period. Dynamic social distancing interventions could reduce the median number of cases in ICU below current estimates of Ontario’s ICU capacity.InterpretationWithout significant social distancing or a combination of moderate social distancing with enhanced case finding, we project that ICU resources would be overwhelmed. Dynamic social distancing could maintain health system capacity and also allow periodic psychological and economic respite for populations.
Prevalence of Malaria from Blood Smears Examination: A Three-Year Retrospective Study from Nakfa Hospital, Eritrea
Authors: Kesete Yafet , Mhretab Shewit , Tesfay Meron 
Published: March 2020

AbstractBackgroundMalaria afflicts more than 90 countries in the tropical and subtropical region in which more than half of cases are present in sub-Saharan, Africa. It is one of the major health issues in Eritrea in which about 3.6 million (71%) of Eritrean population live in areas conducive for high transmission of malaria. Studying its prevalence is necessary to implement effective control measures. Therefore, this study was conducted to determine the three-year prevalence of malaria from peripheral blood smear examination.MethodsA retrospective study was conducted at Nakfa Hospital from September 2016 to August 2019. All demographic details of subjects and positive malaria cases data were collected from laboratory registration book.ResultsThe overall prevalence of smear positive malaria cases was 33.0% (1921 cases out of 5826). Males (58.19%) were more prone to have a positive malaria smear than females (41.8%). A higher prevalence of malaria was observed in the adult age group (35%) compared with children under 5 years old children (27%). The highest prevalence of malaria cases was found in the year 2016 in which correspond to 48.8%. A comparative incidence was also observed during the next year of 2017 with rate of 41% (1087 cases out of 2680) and decreased to low levels in recent couple of years. High slide positive rate was seen in summer (40%) and Autumn (39.52%) whereas Spring had the lowest frequency of cases (14.3%). Similarly, months of July (45%) and September (40.6%) had been noted to have the maximum number of cases.Plasmodium vivaxconstituted the most predominant malaria infections (78.06%), while markedly lowerp. falciparumwas also present (21.26 %). Almost around 70% of cases were reported from patients living in and at the peripheries of Nakfa town.ConclusionEritrea is one of the few countries which has made a profound progress on decreasing transmission of common communicable diseases. However, vigilant surveillance is required especially during malaria transmission peaks from July to October which also overlap with harvesting seasons in Eritrea. Therefore, health planners need to organize intensive health education to increase community awareness via promotion of information and communication.
Enhanced mirroring upon mutual gaze: Multimodal evidence from TMS-assessed corticospinal excitability and the EEG mu rhythm
Authors: Prinsen Jellina , Alaerts Kaat 
Published: March 2020

AbstractEye-to-eye contact is a salient cue for regulating everyday social interaction and communication. Previous research has demonstrated that direct eye contact between actor and observer specifically enhances the ‘mirroring’ of others’ actions in the observer, as measured by transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs; an index of motor cortex excitability during action observation). However, it remains unknown whether other markers of mirror system activation, such as suppression of the EEG mu rhythm (i.e. attenuation of neural oscillations in the 8-13 Hz frequency band over the sensorimotor strip), are also susceptible to perceived eye contact. In the current study, a multimodal approach was adopted to assess both TMS-induced MEPs and EEG mu suppression (in separate sessions), while 32 participants (20 men; mean age: 24;8 years) observed a simple hand movement in combination with direct or averted gaze from the live stimulus person. Both indices of mirror system functioning were significantly modulated by perceived eye gaze; showing a significant increase in MEP amplitude and a significant attenuation of the mu rhythm when movement observation was accompanied with direct compared to averted gaze. Importantly, while inter-individual differences in absolute MEP and mu suppression scores were not significantly related, a significant association was identified between gaze-related changes in MEP responses and mu suppression. As such, it appears that while the neurophysiological substrates underlying mu suppression and TMS-induced MEP responses differ, both are similarly affected by the modulatory impact of gaze-related cues. In sum, our results suggest that both EEG mu rhythm and TMS-induced MEPs are sensitive to the social relevance of the observed actions, and that a similar neural substrate may drive gaze-related changes in these distinct markers of mirror system functioning.
Motor-evoked neural responses in auditory cortex are associated with improved sensitivity to self-generated sounds
Authors: Reznik Daniel , Hacohen Noa , Buaron Batel , Zion-Golumbic Elana , Mukamel Roy 
Published: March 2020

AbstractSensory perception is a product of complex interactions between the internal state of an organism and the physical attributes of a stimulus. One factor that modulates the internal state of the perceiving agent is voluntary movement. It has been shown across the animal kingdom that perception and sensory-evoked physiological responses are modulated depending on whether or not the stimulus is the consequence of voluntary actions. These phenomena are often attributed to motor signals sent to relevant sensory regions (efference copies), that convey information about expected upcoming sensory consequences. However, to date, there is nodirectevidence in humans for efferent signals underlying these motor-sensory interactions. In the current study we recorded neurophysiological (using Magnetoencephalography) and behavioral responses from 16 healthy subjects performing an auditory detection task of faint tones. Tones were either generated by subjects’ voluntary button presses or occurred predictably following a visual cue. By introducing a constant temporal delay between button press/cue and tone delivery and applying source-level analysis we decoupled motor-evoked and auditory-evoked activity in auditory cortex. We show motor-related evoked-responses in auditory cortex following sound-triggering actions and preceding sound onset. Such evoked-responses were not found for button-presses that were not coupled with expected sounds. Furthermore, the amplitude of these evoked-responses corresponded with subsequent sound detection, suggesting their functional relevance to auditory processing. Our results provide firstdirectevidence for efferent signals in sensory cortex that are evoked by voluntary actions coupled with sensory consequences.
Transcriptomic and proteomic dynamics during metamorphosis of Pacific oysterCrassostrea gigas
Authors: Xu Fei , Zhang Guofan 
Published: March 2020

AbstractMany marine invertebrate phyla are characterized by indirect development. These animals transit from planktonic larvae to benthic adults via settlement and metamorphosis, which contributes to the adaption to the marine environment. Studying the biological process of metamorphosis is thus a key to understand the origin and evolution of indirect development. Numerous studies have been conducted on the relationships of metamorphosis with the marine environment, microorganisms, as well as the neurohormones, however, little is known on the gene regulation network (GRN) dynamics during metamorphosis. Metamorphosis competent pediveliger of Pacific oysterCrassostrea gigaswas assayed in this study. By identifying genes enriched in competent pediveliger and early spat, as well as pediveligers treated with epinephrine, the dynamics of genes and proteins was examined with transcriptomics and proteomics methods. The results indicated significantly different gene regulation networks before, during, and post metamorphosis. Genes encoding membrane integrated receptors and related to the remodeling of the nervous system were upregulated before the initiation of metamorphosis. Massive biogenesis, e.g., various enzymes and structural proteins, occurred during metamorphosis. Correspondingly, the protein synthesis system was comprehensively activated after epinephrine stimulation. Hierarchical downstream gene networks were also stimulated, where some transcription factors showed different temporal response patterns, including some important Homeobox, basic helix-loop-helix factors and nuclear receptors. Nuclear receptors, as well as their retinoic acid receptor partners, should play critical roles during the oyster metamorphosis, although they may not be responsible for the initiation process. Enriched genes in early spat were mainly related to environmental stress responses, indicating the GRN complexity of the transition stage during oyster metamorphosis.
Axenicin-vitrocultivation of nineteen peat-moss (SphagnumL.) species as a resource for basic biology, biotechnology and paludiculture
Authors: Heck Melanie A. , Lüth Volker M. , Krebs Matthias , Kohl Mira , Prager Anja , Joosten Hans , Decker Eva L. , Reski Ralf 
Published: March 2020

SummaryThe cultivation ofSphagnummosses reduces CO2emissions by rewetting drained peatlands and by substituting peat with renewable biomass. ‘Sphagnum farming’ requires large volumes of founder material, which can only be supplied sustainably by axenic cultivation in bioreactors.We established axenicin-vitrocultures from sporophytes of 19Sphagnumspecies collected in Austria, Germany, Latvia, Netherlands, Russia and Sweden, namelyS. angustifolium, S. balticum, S. capillifolium, S. centrale, S. compactum, S. cuspidatum, S. fallax, S. fimbriatum, S. fuscum, S. lindbergii, S. medium/divinum, S. palustre, S. papillosum, S. rubellum, S. russowii, S. squarrosum, S. subnitens, S. subfulvum, andS. warnstorfii. These species cover five of the six EuropeanSphagnumsections, namelyAcutifolia, Cuspidata, Rigida, SphagnumandSquarrosa.Their growth was measured in axenic suspension cultures, whereas their ploidy was determined by flow cytometry and compared with the genome size ofPhyscomitrella patens. We identified haploid and diploidSphagnumspecies, found that their cells are predominantly arrested in the G1-phase of the cell cycle, and did not find a correlation between plant productivity and ploidy.With this collection, high-quality founder material for diverse large-scale applications but also for basicSphagnumresearch is available from the International Moss Stock Center (IMSC).
Physical confinement impacts cellular phenotype within living materials
Authors: Priks Hans , Butelmann Tobias , Illarionov Aleksandr , Johnston Trevor G. , Fellin Christopher , Tamm Tarmo , Nelson Alshakim , Kumar Rahul , Lahtvee Petri-Jaan 
Published: March 2020

AbstractAdditive manufacturing allows three-dimensional printing of polymeric materials together with cells, creating living materials for applications in biomedical research and biotechnology. However, understanding the cellular phenotype within living materials is lacking and a key limitation for their wider application. Herein, we present an approach to characterize the cellular phenotype within living materials. We immobilized the budding yeastSaccharomyces cerevisiaein three different photocross-linkable triblock polymeric hydrogels containing F127-bis-urethane methacrylate, F127-dimethacrylate, or poly(alkyl glycidyl ether)-dimethacrylate. Using optical and scanning electron microscopy, we showed that hydrogels based on these polymers were stable under physiological conditions, but yeast colonies showed differences in the interaction within the living materials. We found that the physical confinement, imparted by compositional and structural properties of the hydrogels, impacted the cellular phenotype by reducing the size of cells in living materials compared with suspension cells. These properties also contributed to the differences in immobilization patterns, growth of colonies, and colony coatings. We observed that a composition-dependent degradation of polymers was likely possible by cells residing in the living materials. In conclusion, our investigation highlights the need for a holistic understanding of the cellular response within hydrogels to facilitate the synthesis of application-specific polymers and the design of advanced living materials in the future.
Temporal resource continuity increases predator abundance in a metapopulation model: insights for conservation and biocontrol
Authors: Spiesman Brian J. , Iuliano Benjamin , Gratton Claudio 
Published: March 2020

AbstractThe amount of habitat in a landscape is an important metric for evaluating the effects of land cover and land use on biodiversity and ecosystem services, yet it fails to capture complex temporal dimensions of resource availability that could be consequential for species population dynamics. If ephemeral resources across multiple habitat patches are synchronously available, resource gaps could be detrimental to population growth. In contrast, asynchronously available resources create a mosaic of temporally complementary resources that mobile organisms can track across the landscape. Knowledge is especially lacking on the relevance of temporal complementation for tri-trophic interactions and biological pest control. Here we use a spatially-explicit predator-prey metapopulation model to test the effect of different spatiotemporal resource patterns on insect predators and their prey. We examined prey and predator responses in model landscapes that varied in both the amount and temporal variability of basal vegetation resources. Further, we examined cases where prey comprised either a single generalist species or two specialist species that use different resources available either early or late in the growing season. We found that predators and generalist prey benefitted from lower temporal variance of basal resources, which increased both of their landscape-scale abundances. However, increasing the amount of basal resources also increased the variability of generalist prey populations, resulting in a negative correlation between basal resource amount and predator abundance. Specialist prey, on the other hand, did not benefit from less temporally variable in basal resources, since they were restricted by habitat type while also suffering greater predation. Predators feeding on specialists achieved greater prey suppression in landscapes with less temporally variable resources. Our simulations demonstrate the joint importance of landscape-scale temporal dynamics of resources and resource amount in understanding how landscape heterogeneity influences biodiversity and ecosystem services such as the biological control of agricultural pests.