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2021 ◽  
Vol 8 ◽  
pp. 27-44
Author(s):  
Charlotte Priddy ◽  
Amy Regis ◽  
Stuart Clarke ◽  
A. Leslie ◽  
Thomas Dodd

This study presents a detailed synopsis of the sedimentological and structural features displayed within an underdescribed enigmatic facies observed in the basal Lower Jurassic Kayenta Formation of the Colorado Plateau. The facies comprises pebble to cobble-sized clasts of fine to medium-grained crossbedded sandstone with mud-draped and deformed foresets, as well as clasts of parallel-laminated but highly contorted siltstone and mudstone, supported in a silty to sandy matrix. The deposits are internally deformed and show both ductile and brittle structures in close spatial proximity, with a consistent and pervasive westdirected sense of shear. The facies occurs consistently within the same approximate stratigraphic interval, at or near the base of the Kayenta Formation. It is, however, observed only at four localities, distributed in a crudely linear arrangement parallel to the Utah-Idaho trough, despite extensive studies of outcrops of the same stratigraphic interval widely distributed across both Utah and Arizona. This study interprets the depositional processes as that of a partially subaerial debris flow with depositional events perhaps taking place during the waning period after ephemeral stream activity. The clast morphology and composition suggests a local source for the sediment entrained within the flow, and a limited transport distance. All of these observations are difficult to reconcile with the consistency of the stratigraphic interval in which the facies occur, or with the regional distribution of preserved examples. Consequently, this study discusses the potential for a common and time-equivalent triggering mechanism across all examples, which may have regional significance in the Jurassic evolution of the region.


2021 ◽  
Vol 923 (1) ◽  
pp. 21
Author(s):  
Denilso Camargo

Abstract This work communicates the discovery of a binary open cluster within the Galaxy. NGC 1605 presents an unusual morphology with a sparse stellar distribution and a double core in close angular proximity. The 2MASS and Gaia-EDR3 field-star decontaminated color–magnitude diagrams (CMDs) show two distinct stellar populations located at the same heliocentric distance of ∼2.6 kpc, suggesting that there are two clusters in the region, NGC 1605a and NGC 1605b, with ages of 2 Gyr and 600 Myr, respectively. Both Gaia parallax and PM distributions are compact and very similar indicating that they are open clusters (OCs) and share the same kinematics. The large age difference, 1.4 Gyr, point to a formation by tidal capture during a close encounter and the close spatial proximity and similar kinematics suggest an ongoing merger event. There is some prominent tidal debris that appears to trace the cluster's orbits during the close encounter and, unexpectedly, some of them appear to be bound structures; this may suggest that in addition to the evaporation, the merging clusters are being broken apart into smaller structures by the combination of the Galactic disk, the Perseus arm, and mutual tidal interactions. In this sense, the newly found binary cluster may be a key object in the observational validation of theoretical studies on binary cluster pairs formation by tidal capture as well as in the formation of massive clusters by merging, and tidal disruption of stellar systems.


Author(s):  
Dolores Piniella ◽  
Elena Martínez-Blanco ◽  
David Bartolomé-Martín ◽  
Ana B. Sanz-Martos ◽  
Francisco Zafra

AbstractDopamine (DA) transporters (DATs) are regulated by trafficking and modulatory processes that probably rely on stable and transient interactions with neighboring proteins and lipids. Using proximity-dependent biotin identification (BioID), we found novel potential partners for DAT, including several membrane proteins, such as the transmembrane chaperone 4F2hc, the proteolipid M6a and a potential membrane receptor for progesterone (PGRMC2). We also detected two cytoplasmic proteins: a component of the Cullin1-dependent ubiquitination machinery termed F-box/LRR-repeat protein 2 (FBXL2), and the enzyme inositol 5-phosphatase 2 (SHIP2). Immunoprecipitation (IP) and immunofluorescence studies confirmed either a physical association or a close spatial proximity between these proteins and DAT. M6a, SHIP2 and the Cullin1 system were shown to increase DAT activity in coexpression experiments, suggesting a functional role for their association. Deeper analysis revealed that M6a, which is enriched in neuronal protrusions (filopodia or dendritic spines), colocalized with DAT in these structures. In addition, the product of SHIP2 enzymatic activity (phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2]) was tightly associated with DAT, as shown by co-IP and by colocalization of mCherry-DAT with a specific biosensor for this phospholipid. PI(3,4)P2 strongly stimulated transport activity in electrophysiological recordings, and conversely, inhibition of SHIP2 reduced DA uptake in several experimental systems including striatal synaptosomes and the dopaminergic cell line SH-SY5Y. In summary, here we report several potential new partners for DAT and a novel regulatory lipid, which may represent new pharmacological targets for DAT, a pivotal protein in dopaminergic function of the brain.


Author(s):  
Natalie Viscariello ◽  
Matthew D. Greer ◽  
Upendra Parvathaneni ◽  
Jay J. Liao ◽  
George E. Laramore ◽  
...  

Abstract Purpose Neutron therapy is a high linear energy transfer modality that is useful for the treatment of radioresistant head and neck (H&N) cancers. It has been limited to 3-dimensioanal conformal-based fast-neutron therapy (3DCNT), but recent technical advances have enabled the clinical implementation of intensity-modulated neutron therapy (IMNT). This study evaluated the comparative dosimetry of IMNT and 3DCNT plans for the treatment of H&N cancers. Materials and Methods Seven H&N IMNT plans were retrospectively created for patients previously treated with 3DCNT at the University of Washington (Seattle). A custom RayStation model with neutron-specific scattering kernels was used for inverse planning. Organ-at-risk (OAR) objectives from the original 3DCNT plan were initially used and were then systematically reduced to investigate the feasibility of improving a therapeutic ratio, defined as the ratio of the mean tumor to OAR dose. The IMNT and 3DCNT plan quality was evaluated using the therapeutic ratio, isodose contours, and dose volume histograms. Results When compared with the 3DCNT plans, IMNT reduces the OAR dose for the equivalent tumor coverage. Moreover, IMNT is most advantageous for OARs in close spatial proximity to the target. For the 7 patients with H&N cancers examined, the therapeutic ratio for IMNT increased by an average of 56% when compared with the 3DCNT. The maximum OAR dose was reduced by an average of 20.5% and 20.7% for the spinal cord and temporal lobe, respectively. The mean dose to the larynx decreased by an average of 80%. Conclusion The IMNT significantly decreases the OAR doses compared with 3DCNT and provides comparable tumor coverage. Improvements in the therapeutic ratio with IMNT are especially significant for dose-limiting OARs near tumor targets. Moreover, IMNT provides superior sparing of healthy tissues and creates significant new opportunities to improve the care of patients with H&N cancers treated with neutron therapy.


2021 ◽  
Author(s):  
Anna K. Simonsen

AbstractBacteria have highly flexible pangenomes, which are thought to facilitate evolutionary responses to environmental change, but the impacts of environmental stress on pangenome evolution remain unclear. Using a landscape pangenomics approach, I demonstrate that environmental stress leads to consistent, continuous reduction in genome content along four environmental stress gradients (acidity, aridity, heat, salinity) in naturally occurring populations of Bradyrhizobium diazoefficiens (widespread soil-dwelling plant mutualists). Using gene-level network and duplication functional traits to predict accessory gene distributions across environments, genes predicted to be superfluous are more likely lost in high stress, while genes with multi-functional roles are more likely retained. Genes with higher probabilities of being lost with stress contain significantly higher proportions of codons under strong purifying and positive selection. Gene loss is widespread across the entire genome, with high gene-retention hotspots in close spatial proximity to core genes, suggesting Bradyrhizobium has evolved to cluster essential-function genes (accessory genes with multifunctional roles and core genes) in discrete genomic regions, which may stabilise viability during genomic decay. In conclusion, pangenome evolution through genome streamlining are important evolutionary responses to environmental change. This raises questions about impacts of genome streamlining on the adaptive capacity of bacterial populations facing rapid environmental change.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2101
Author(s):  
Andrea M. Harvey ◽  
John M. Morton ◽  
David J. Mellor ◽  
Vibeke Russell ◽  
Rosalie S. Chapple ◽  
...  

We previously developed a Ten-Stage Protocol for scientifically assessing the welfare of individual free-roaming wild animals using the Five Domains Model. The protocol includes developing methods for measuring or observing welfare indices. In this study, we assessed the use of remote camera traps to evaluate an extensive range of welfare indicators in individual free-roaming wild horses. Still images and videos were collected and analysed to assess whether horses could be detected and identified individually, which welfare indicators could be reliably evaluated, and whether behaviour could be quantitatively assessed. Remote camera trapping was successful in detecting and identifying horses (75% on still images and 72% on video observation events), across a range of habitats including woodlands where horses could not be directly observed. Twelve indicators of welfare across the Five Domains were assessed with equal frequency on both still images and video, with those most frequently assessable being body condition score (73% and 79% of observation events, respectively), body posture (76% for both), coat condition (42% and 52%, respectively), and whether or not the horse was sweating excessively (42% and 45%, respectively). An additional five indicators could only be assessed on video; those most frequently observable being presence or absence of weakness (66%), qualitative behavioural assessment (60%), presence or absence of shivering (51%), and gait at walk (50%). Specific behaviours were identified in 93% of still images and 84% of video events, and proportions of time different behaviours were captured could be calculated. Most social behaviours were rarely observed, but close spatial proximity to other horses, as an indicator of social bonds, was recorded in 36% of still images, and 29% of video observation events. This is the first study that describes detailed methodology for these purposes. The results of this study can also form the basis of application to other species, which could contribute significantly to advancing the field of wild animal welfare.


Author(s):  
Guus Christian van Bentum ◽  
Marc Mathijs van Wanrooij ◽  
A. John Van Opstal

To program a goal-directed response in the presence of acoustic reflections, the audio-motor system should suppress the detection of time-delayed sources. We examined the effects of spatial separation and inter-stimulus delay on the ability of human listeners to localize a pair of broadband sounds in the horizontal plane. Participants indicated how many sounds were heard and where these were perceived by making one or two head-orienting localization responses. Results suggest that perceptual fusion of the two sounds depends on delay and spatial separation. Leading and lagging stimuli in close spatial proximity required longer stimulus delays to be perceptually separated than those further apart. Whenever participants heard one sound, their localization responses for synchronous sounds were oriented to a weighted average of both source locations. For short delays, responses were directed towards the leading stimulus location. Increasing spatial separation enhanced this effect. For longer delays, responses were again directed towards a weighted average. When participants perceived two sounds, the first and the second response were directed to either of the leading and lagging source locations. Perceived locations were interchanged often in their temporal order (in ~40% of trials). We show that the percept of two sounds occurring requires sufficient spatiotemporal separation, after which localization can be performed with high accuracy. We propose that the percept of temporal order of two concurrent sounds results from a different process than localization, and discuss how dynamic lateral excitatory-inhibitory interactions within a spatial sensorimotor map could explain the findings.


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 973
Author(s):  
Geoffrey R. Squire ◽  
Mark Young ◽  
Linda Ford ◽  
Gillian Banks ◽  
Cathy Hawes

Soil organic carbon (SOC) is declining globally due to intensification of agriculture. Reversing declines should reduce soil erosion, maintain yields, raise the soil’s atmospheric carbon sink, and improve habitat for biodiversity. Commercial fields were sampled in a diverse European Atlantic zone cropland to relate SOC status to cropping intensity and to define a realistic target for restoration. SOC (%C by mass) decreased from 4% to 2% as the proportion of high-intensity crops increased from zero to 55% (linear regression, F pr. < 0.001). In further sampling in and around high-intensity fields, mean SOC increased from 2.4% in cultivated soil to 3.3% in field margins and 4.8% in nearby uncultivated land (F pr. < 0.001). Three broad zones of SOC in close spatial proximity were then defined: 1) high-intensity arable from 1% to 3%, 2) mid-intensity arable and arable-grass from 3% to 5% and 3) uncultivated and semi-natural land from 5% upwards. C:N ratio was constrained around 12, unaffected by cropping intensity, but slightly lower in fields than in margins and uncultivated land (F pr. < 0.001). A feasible target SOC of just above 3% was defined for high-intensity sites. There should be no biophysical obstacle to raising SOC above 3% in the high-input sector. Results argue against treating cropland of this type as uniform: assessment and restoration should be implemented field by field.


2020 ◽  
Vol 117 (23) ◽  
pp. 13033-13043
Author(s):  
Ayelen Lizarraga ◽  
Zach Klapholz O’Brown ◽  
Konstantinos Boulias ◽  
Lara Roach ◽  
Eric Lieberman Greer ◽  
...  

Trichomonas vaginalisis a common sexually transmitted parasite that colonizes the human urogenital tract causing infections that range from asymptomatic to highly inflammatory. Recent works have highlighted the importance of histone modifications in the regulation of transcription and parasite pathogenesis. However, the nature of DNA methylation in the parasite remains unexplored. Using a combination of immunological techniques and ultrahigh-performance liquid chromatography (UHPLC), we analyzed the abundance of DNA methylation in strains with differential pathogenicity demonstrating that N6-methyladenine (6mA), and not 5‐methylcytosine (5mC), is the main DNA methylation mark inT. vaginalis. Genome-wide distribution of 6mA reveals that this mark is enriched at intergenic regions, with a preference for certain superfamilies of DNA transposable elements. We show that 6mA inT. vaginalisis associated with silencing when present on genes. Interestingly, bioinformatics analysis revealed the presence of transcriptionally active or repressive intervals flanked by 6mA-enriched regions, and results from chromatin conformation capture (3C) experiments suggest these 6mA flanked regions are in close spatial proximity. These associations were disrupted when parasites were treated with the demethylation activator ascorbic acid. This finding revealed a role for 6mA in modulating three-dimensional (3D) chromatin structure and gene expression in this divergent member of the Excavata.


2020 ◽  
Vol 32 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Veronica Mäki-Marttunen ◽  
Thomas Hagen ◽  
Bruno Laeng ◽  
Thomas Espeseth

When engaged in dynamic visuospatial tasks, the brain copes with perceptual and cognitive processing challenges. During multiple-object tracking (MOT), the number of objects to be tracked (i.e., load) imposes attentional demands, but so does spatial interference from irrelevant objects (i.e., close encounters). Presently, it is not clear whether the effect of load on accuracy solely depends on the number of close encounters. If so, the same cognitive and physiological mechanisms deal with increasing load by preparing for and dealing with spatial interference. However, this has never been directly tested. Such knowledge is important to understand the neurophysiology of dynamic visual attention and resolve conflicting views within visual cognition concerning sources of capacity limitations. We varied the processing challenge in MOT task in two ways: the number of targets and the minimum spatial proximity between targets and distractors. In a first experiment, we measured task-induced pupil dilations and saccades during MOT. In a separate cohort, we measured fMRI activity. In both cohorts, increased load and close encounters (i.e., close spatial proximity) led to reduced accuracy in an additive manner. Load was associated with pupil dilations, whereas close encounters were not. Activity in dorsal attentional areas and frequency of saccades were proportionally larger both with higher levels of load and close encounters. Close encounters recruited additionally ventral attentional areas that may reflect orienting mechanisms. The activity in two brainstem nuclei, ventral tegmental area/substantia nigra and locus coeruleus, showed clearly dissociated patterns. Our results constitute convergent evidence indicating that different mechanisms underlie processing challenges due to load and object spacing.


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