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Fisher information for the design of diffuse optical brain monitoring systems
No full textDiffuse optical tomography is a non-invasive technique for assessing tissue structure and function by detecting scattered near-infrared light. A key question is how to select source–detector configurations and measurement modalities to maximize sensitivity, particularly for brain defect (e.g., tumor, stroke, etc.) monitoring. This study proposes Fisher information as a rapid, quantitative metric to optimize source-detector placement. We compare the performance of continuous-wave and time-resolved measurements and also explore the impact of cerebrospinal fluid on system design. This method confirms some known results but also highlights some counterintuitive results, including the finding that optimal source-detector distance depends on the type of detector and its related noise statistics and that the low-scattering cerebral spinal fluid layer in the brain can enhance measurement sensitivity. This is found to depend on how exactly the data is collected and processed, with fully time-resolved data always showing a net gain. Our results provide an efficient framework for analyzing and designing diffuse optical imaging systems for non-invasive monitoring and imaging via diffuse light
Diminished osteoprotegerin production by gingival fibroblasts from periodontitis patients is associated with their reduced ability to suppress osteoclastogenesis
Get PDFOsteoclast-mediated alveolar bone resorption is a key hallmark of periodontitis. Gingival fibroblasts (GFs) play multifaceted roles in the progression of chronic inflammation; however, their involvement in osteoclastogenesis remains controversial. Here, we analyzed the effects of mediators secreted by GFs from healthy donors and periodontitis patients on osteoclast formation. We observed strong suppression of receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis by conditioned media from healthy donor GFs, which was independent of any prior in vitro stimulation or infection. These media contained high levels of osteoprotegerin (OPG), and GFs were identified as the main OPG source in gingival tissue using a 3D organotypic reconstructed human gingiva model and a single-cell RNA-seq dataset. Notably, GFs from periodontitis patients produced significantly less OPG compared to GFs from healthy individuals and were less effective at suppressing osteoclastogenesis. Finally, siRNA-mediated silencing of OPG expression in GFs from periodontitis patients further decreased their inhibitory effect on osteoclast formation, confirming the central role of OPG in osteoclastogenesis regulation by GFs. Collectively, these results demonstrate that in healthy gingival tissue, GFs exert bone-protective effects by inhibiting osteoclast formation. However, prolonged exposure to the microenvironment of the inflamed gingival tissue could impair this protective function through sustained reduction of OPG production, which may contribute to alveolar bone resorption in periodontitis
InvestEU: neoliberal lineages and contradictions in the new EU industrial policy
Get PDFThe notion of an industrial policy renaissance has become a defining theme in recent political economy scholarship. In the European Union (EU), scholars have identified the emergence of a “new EU industrial policy” aimed at strengthening EU leadership in key strategic sectors. A central debate concerns whether this embodies a substantive break from or a continuity with prior neoliberal frameworks. In this article, we argue that addressing this question requires moving beyond the macro-structural level of the new EU industrial policy “in general” towards examining its component elements “in particular.” Focussing on InvestEU—a flagship programme designed to mobilise public and private capital in support of strategic industrial policy goals—we demonstrate how the development, architecture, and implementation of this key initiative reveals significant continuities with past policy practices. Rather than treating this as conclusive evidence of neoliberal continuity, we argue that the case study illuminates important contradictions within the EU’s new industrial policy
Search for dynamical black hole captures enhanced with Gaussian mixture modeling
No full textGravitational waves (GWs) are expected to originate from black holes interacting dynamically in dense
astrophysical environments. In such environments, given that the velocity and cross section between the
interacting black holes are low, dynamical capture may occur. Such events merge on very short
timescales with high eccentricities and are expected to be detectable in the LIGO-Virgo-KAGRA (LVK)
sensitivity band. In this work, we present a dedicated search for dynamical black hole capture
events in the third LVK observing run (O3) with the coherent WaveBurst (cWB) algorithm
enhanced with Gaussian mixture modeling (GMM) postproduction. With this we consider two
applications of GMM: a weakly modeled approach searching for generic short transients under minimal
assumptions, and a population-informed approach, in which the GMM model is provided information on
the parameter space occupied by the capture population. Although our search does not find any new
significant GW events, we find that an informed GMM approach brings significant sensitivity
improvements, enabling the detection of dynamical capture events up to a distance of 1.9 Gpc for a
200M⊙ equal-mass binary. We present updated upper limit estimates of the rate at 90% confidence, the
most stringent of which is 0.15 Gpc−3 yr−1, a 34% improvement with respect to previous observational
estimates. Furthermore, while the weakly modeled GMM approach is less sensitive to dynamical capture
systems, we find that it is possible for these events to be detected up to a distance of 1 Gpc in the cWBGMM all-sky short search under minimal assumptions. Finally, with the confident detection of
GW190521, we estimate the rate of similar events to be 0.94 Gpc−3 yr−1, assuming the event originated
from a dynamical capture
Persistent cycles and long-run covariability in paleoclimate time series
No full textNo abstract available
Flow history effects on river bifurcation dynamics in a Himalayan river
Get PDFDynamic gravel bed rivers experience frequent changes in channel position and flow distribution between branches, which can alter the location and extent of flooding. Changes in flow routing can significantly impact livelihoods, habitats and infrastructure in adjacent floodplains. Here, we test whether variations in seasonal discharge patterns cause instability in channel position and flow distribution in a gravel bed river system around a major channel bifurcation. Satellite images of the Karnali River, Nepal, were assessed over a 30-year period to identify changes in channel position and flow partitioning downstream of the bifurcation. These observations were compared with daily discharge records to establish whether the sequencing of peak monsoonal flows coincided with geomorphic changes in the river. Changes to flow partitioning trends were consistently preceded by monsoon seasons with two large peak flows, suggesting a history-dependent threshold in the channels. To explain this observation, we use grain-size data from gravel bars that reveal variable grain clustering and bed armoring across the channel network. We propose that two high discharges are needed to transition between phases of bifurcation stability or instability, where the first event acts to break down the bed armor layer, allowing the second high flow to drive enlargement/closure of branches and reworking of the bed. Our findings suggest that flow sequencing is an important driver in flow distribution and stability at bifurcations in gravel bed rivers. Although the focus is on Himalayan rivers, the findings may be of relevance in other areas that experience changing seasonal flood regimes
The deceptive simplicity of the Scholarship of Teaching and Learning
No full textNo abstract available
'Build, baby, build'? A critical assessment of housing policy over the first year of the Labour Government in the UK
Get PDFHousing policy has been a busy area of activity for the Labour government in its first year. In this paper we critically assess the tensions and contradictions within these housing policy changes, examining whether they add up to a coherent, programmatic response to the ‘housing crisis’ which can deliver for individuals and households struggling to access and sustain adequate housing after 14 years of austerity and neglect. In particular, we question the underlying driver of the housebuilding target and ask whether the Labour government’s apparent desperation for economic growth is subsuming concerns for social justice, despite the increase in support for social housing – a debate with wide international resonance in the current economic context. Finally, we scrutinise whether the rapid start out of the blocks on housing policy can be maintained for the inevitable marathon that is necessary to make significant changes to the UK housing system
Neutron interaction properties of structural materials for multi-grid neutron detectors
Get PDFThe T-REX neutron time-of-flight spectrometer at the European Spallation Source will use MultiGrid Technology, which relies on thin B4C coatings on the Al blades of the grids to detect scattered thermal neutrons. Following a Monte Carlo study of internal shielding to suppress neutron multiple scattering in T-REX, the neutron transmission and scattering properties of 12 shielding-material samples have been measured at the ISIS spallation neutron source. Neutron transmission was measured on the EMMA beam line at wavelengths 0.5-4.7 Å, using a 2D-position-sensitive, neutron GEM detector, while neutron scattering was measured for 6 of the samples at the Merlin spectrometer, at wavelengths 0.72, 1.28, 1.85 and 2.41 Å. The present tests show that a B4C/Al composite material, plated with Ni to stop intrinsic alpha background, is an effective neutron absorber, suitable for incorporation in the Multi-Grid structures which detect the neutrons in inelastic neutron spectrometers
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