497 research outputs found
A low-energy perspective on the minimal left-right symmetric model
We perform a global analysis of the low-energy phenomenology of the minimal
left-right symmetric model (mLRSM) with parity symmetry. We match the mLRSM to
the Standard Model Effective Field Theory Lagrangian at the left-right-symmetry
breaking scale and perform a comprehensive fit to low-energy data including
mesonic, neutron, and nuclear -decay processes, and CP-even and -odd processes in the bottom and strange sectors, and electric
dipole moments (EDMs) of nucleons, nuclei, and atoms. We fit the
Cabibbo-Kobayashi-Maskawa and mLRSM parameters simultaneously and determine a
lower bound on the mass of the right-handed boson. In models where a
Peccei-Quinn mechanism provides a solution to the strong CP problem, we obtain
TeV at C.L. which can be significantly improved
with next-generation EDM experiments. In the -symmetric mLRSM without a
Peccei-Quinn mechanism we obtain a more stringent constraint TeV at C.L., which is difficult to improve with low-energy
measurements alone. In all cases, the additional scalar fields of the mLRSM are
required to be a few times heavier than the right-handed gauge bosons. We
consider a recent discrepancy in tests of first-row unitarity of the CKM
matrix. We find that, while TeV-scale bosons can alleviate some of the
tension found in the determinations, a solution to the discrepancy
is disfavored when taking into account other low-energy observables within the
mLRSM.Comment: 42 pages plus appendices. Published versio
Review on the simultaneous determination of total prostate-specific antigen and free prostate-specific antigen
Differential activation of frontoparietal attention networks by social and symbolic spatial cues
Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer’s attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a ‘special’ category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain’s response during target localization in which laterally presented targets were preceded by uninformative gaze or arrow cues. Reaction times were faster during valid than invalid trials for both arrow and gaze cues. However, differential patterns of activity were evoked in the brain. Trials including invalid rather than valid arrow cues resulted in a stronger hemodynamic response in the ventral attention network. No such difference was seen during trials including valid and invalid gaze cues. This differential engagement of the ventral reorienting network is consistent with the notion that the facilitation of target detection by gaze cues and arrow cues is subserved by different neural substrates
Differential Activation of Frontoparietal Attention Networks by Social and Symbolic Spatial Cues
Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer’s attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a ‘special’ category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain’s response during target localization in which laterally presented targets were preceded by uninformative gaze or arrow cues. Reaction times were faster during valid than invalid trials for both arrow and gaze cues. However, differential patterns of activity were evoked in the brain. Trials including invalid rather than valid arrow cues resulted in a stronger hemodynamic response in the ventral attention network. No such difference was seen during trials including valid and invalid gaze cues. This differential engagement of the ventral reorienting network is consistent with the notion that the facilitation of target detection by gaze cues and arrow cues is subserved by different neural substrates
Transcriptome analysis reveals the contribution of oligodendrocyte and radial glia-derived cues for maintenance of microglia identity
Microglia are increasingly being recognized as druggable targets in neurodegenerative disorders, and good in vitro models are crucial to address cell biological questions. Major challenges are to recapitulate the complex microglial morphology and their in vivo transcriptome. We have therefore exposed primary microglia from adult rhesus macaques to a variety of different culture conditions including exposure to soluble factors as M-CSF, IL-34, and TGF-β as well as serum replacement approaches, and compared their morphologies and transcriptomes to those of mature, homeostatic in vivo microglia. This enabled us to develop a new, partially serum-free, monoculture protocol, that yields high numbers of ramified cells. We also demonstrate that exposure of adult microglia to M-CSF or IL-34 induces similar transcriptomes, and that exposure to TGF-β has much less pronounced effects than it does on rodent microglia. However, regardless of culture conditions, the transcriptomes of in vitro and in vivo microglia remained substantially different. Analysis of differentially expressed genes inspired us to perform 3D-spherical coculture experiments of microglia with oligodendrocytes and radial glia. In such spheres, microglia signature genes were strongly induced, even in the absence of neurons and astrocytes. These data reveal a novel role for oligodendrocyte and radial glia-derived cues in the maintenance of microglial identity, providing new anchor points to study microglia in health and disease
Right ventricular peak systolic longitudinal strain is a sensitive marker for right ventricular deterioration in adult patients with tetralogy of Fallot
The aim of this study was to evaluate the feasibility of right ventricular (RV) longitudinal peak systolic strain (LPSS) assessment for the follow-up of adult patients with corrected tetralogy of Fallot (TOF). Adult patients (n = 18) with corrected TOF underwent echocardiography and CMR twice with a time interval of 4.2 ± 1.7 years. RV performance was derived from CMR, and included RV volumes and ejection fraction (EF). LPSS was calculated globally (GLPSS) and in the RV free wall (LPSS FW), with echocardiographic speckle-tracking strain-analysis. Baseline (G)LPSS values were compared between patients and healthy controls; the relation between (G)LPSS and CMR parameters was evaluated and the changes in (G)LPSS and CMR parameters during follow-up were compared. GLPSS and LPSS FW were significantly reduced in patients as compared to controls (−14.9 ± 0.7% vs. −21.6 ± 0.9% and −15.5 ± 0.9% vs. −22.7 ± 1.5%, P < 0.01). Moderate agreement between LPSS and CMR parameters was observed. RV EF remained unchanged during follow-up, whereas GLPSS and LPSS FW demonstrated a significant reduction. RVEF showed a 1% increase, whereas GLPSS decreased by 14%, and LPSS FW by 27%. RV LPSS is reduced in TOF patients as compared to controls; during follow-up RV EF remained unchanged whereas LPSS decreased suggesting that RV LPSS may be a sensitive marker to detect early deterioration in RV performance
Field Testing of a Novel Drilling Technique to Expand Well Diameters at Depth in Unconsolidated Formations
Larger well diameters allow higher groundwater abstraction rates. But particularly for the construction of wells at greater depth, it may be more cost-efficient to only expand the borehole in the target aquifer. However, current drilling techniques for unconsolidated formations are limited by their expansion factors (<2) and diameters (<1000 mm). Therefore, we developed a new technique aiming to expand borehole diameters at depth in a controlled manner using a low-pressure water jet perpendicular to the drilling direction and extendable by means of a pivoting arm. During a first field test, the borehole diameter was expanded 2.6-fold from 600 to 1570 mm at a depth of 53.5 to 68 m and equipped with a well screen to create an expanded diameter gravel well (EDGW). In keeping with the larger diameter, the volume flux per m screen length was two times higher than conventional 860 mm diameter wells at the site in the subsequent 3 year production period. Although borehole clogging was slower on a volumetric basis and similar when normalized to borehole wall area, rehabilitation of particle clogging at the borehole wall was more challenging due to the thickness of the gravel pack. While jetting the entire borehole wall before backfilling holds promise to remove filter cake and thus limit particle clogging, we found that a second borehole (expanded 4.1-fold to 2460 mm) collapsed during jetting. Overall, the EDGW technique has potential to make the use of deeper unconsolidated aquifers economically (more) feasible, although further understanding of the borehole stability and rehabilitation is required to assess its wider applicability
Intravital correlated microscopy reveals differential macrophage and microglial dynamics during resolution of neuroinflammation
Many brain diseases involve activation of resident and peripheral immune cells to clear damaged and dying neurons. Which immune cells respond in what way to cues related to brain disease, however, remains poorly understood. To elucidate these in vivo immunological events in response to brain cell death we used genetically targeted cell ablation in zebrafish. Using intravital microscopy and large-scale electron microscopy, we defined the kinetics and nature of immune responses immediately following injury. Initially, clearance of dead cells occurs by mononuclear phagocytes, including resident microglia and macrophages of peripheral origin, whereas amoeboid microglia are exclusively involved at a later stage. Granulocytes, on the other hand, do not migrate towards the injury. Remarkably, following clearance, phagocyte numbers decrease, partly by phagocyte cell death and subsequent engulfment of phagocyte corpses by microglia. Here, we identify differential temporal involvement of microglia and peripheral macrophages in clearance of dead cells in the brain, revealing the chronological sequence of events in neuroinflammatory resolution. Remarkably, recruited phagocytes undergo cell death and are engulfed by microglia. Because adult zebrafish treated at the larval stage lack signs of pathology, it is likely that this mode of resolving immune responses in brain contributes to full tissue recovery. Therefore, these findings suggest that control of such immune cell behavior could benefit recovery from neuronal damage.</p
A database of whole-body action videos for the study of action, emotion, and untrustworthiness
We present a database of high-definition (HD) videos for the study of traits inferred from whole-body actions. Twenty-nine actors (19 female) were filmed performing different actions—walking, picking up a box, putting down a box, jumping, sitting down, and standing and acting—while conveying different traits, including four emotions (anger, fear, happiness, sadness), untrustworthiness, and neutral, where no specific trait was conveyed. For the actions conveying the four emotions and untrustworthiness, the actions were filmed multiple times, with the actor conveying the traits with different levels of intensity. In total, we made 2,783 action videos (in both two-dimensional and three-dimensional format), each lasting 7 s with a frame rate of 50 fps. All videos were filmed in a green-screen studio in order to isolate the action information from all contextual detail and to provide a flexible stimulus set for future use. In order to validate the traits conveyed by each action, we asked participants to rate each of the actions corresponding to the trait that the actor portrayed in the two-dimensional videos. To provide a useful database of stimuli of multiple actions conveying multiple traits, each video name contains information on the gender of the actor, the action executed, the trait conveyed, and the rating of its perceived intensity. All videos can be downloaded free at the following address: http://www-users.york.ac.uk/~neb506/databases.html. We discuss potential uses for the database in the analysis of the perception of whole-body actions
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