769 research outputs found
Weak and Semi-Strong Form Stock Return Predictability Revisited
This paper makes indirect inference about the time-variation in expected stock returns by comparing unconditional sample variances to estimates of expected conditional variances. The evidence reveals more predictability as more information is used, and no evidence that predictability has diminished in recent years. Semi-strong form evidence suggests that time-variation in expected returns remains economically important.
Weak and Semi-Strong Form Stock Return Predictability, Revisited
This paper makes indirect inference about the time-variation in expected stock returns by comparing unconditional sample variances to estimates of expected conditional variances. The evidence reveals more predictability as more information is used, and no evidence that predictability has diminished in recent years. Semi-strong form evidence suggests that time-variation in expected returns remains economically important.
Innovative Digital Storytelling with AIGC: Exploration and Discussion of Recent Advances
Digital storytelling, as an art form, has struggled with cost-quality
balance. The emergence of AI-generated Content (AIGC) is considered as a
potential solution for efficient digital storytelling production. However, the
specific form, effects, and impacts of this fusion remain unclear, leaving the
boundaries of AIGC combined with storytelling undefined. This work explores the
current integration state of AIGC and digital storytelling, investigates the
artistic value of their fusion in a sample project, and addresses common issues
through interviews. Through our study, we conclude that AIGC, while proficient
in image creation, voiceover production, and music composition, falls short of
replacing humans due to the irreplaceable elements of human creativity and
aesthetic sensibilities at present, especially in complex character animations,
facial expressions, and sound effects. The research objective is to increase
public awareness of the current state, limitations, and challenges arising from
combining AIGC and digital storytelling.Comment: Project page:
https://lsgm-demo.github.io/Leveraging-recent-advances-of-foundation-models-for-story-telling
Cytological and transcript analyses reveal fat and lazy persister-like bacilli in tuberculous sputum
As nonreplicating tubercle bacilli are tolerant to the cidal action of antibiotics and resistant to multiple stresses, identification of this persister-like population of tubercle bacilli in sputum presents exciting and tractable new opportunities to investigate both responses to chemotherapy and the transmission of tuberculosis
The role of aerodynamic resistance in thermal remote sensing-based evapotranspiration models
Aerodynamic resistance (hereafter ra) is a preeminent variable in evapotranspiration (ET) modelling. The accurate quantification of ra plays a pivotal role in determining the performance and consistency of thermal remote sensing-based surface energy balance (SEB) models for estimating ET at local to regional scales. Atmospheric stability links ra with land surface temperature (LST) and the representation of their interactions in the SEB models determines the accuracy of ET estimates. The present study investigates the influence of ra and its relation to LST uncertainties on the performance of three structurally different SEB models. It used data from nine Australian OzFlux eddy covariance sites of contrasting aridity in conjunction with MODIS Terra and Aqua LST and leaf area index (LAI) products. Simulations of the sensible heat flux (H) and the latent heat flux (LE, the energy equivalent of ET in W/m2) from the SPARSE (Soil Plant Atmosphere and Remote Sensing Evapotranspiration), SEBS (Surface Energy Balance System) and STIC (Surface Temperature Initiated Closure) models forced with MODIS LST, LAI, and in-situ meteorological datasets were evaluated against flux observations in water-limited (arid and semi-arid) and energy-limited (mesic) ecosystems from 2011 to 2019. Our results revealed an overestimation tendency of instantaneous LE by all three models in the water-limited shrubland, woodland and grassland ecosystems by up to 50% on average, which was caused by an underestimation of H. Overestimation of LE was associated with discrepancies in ra retrievals under conditions of high atmospheric instability, during which uncertainties in LST (expressed as the difference between MODIS LST and in-situ LST) apparently played a minor role. On the other hand, a positive difference in LST coincided with low ra (high wind speeds) and caused a slight underestimation of LE at the water-limited sites. The impact of ra on the LE residual error was found to be of the same magnitude as the influence of LST uncertainties in the semi-arid ecosystems as indicated by variable importance in projection (VIP) coefficients from partial least squares regression above unity. In contrast, our results for the mesic forest ecosystems indicated minor dependency on ra for modelling LE (VIP \u3c 0.4), which was due to a higher roughness length and lower LST resulting in the dominance of mechanically generated turbulence, thereby diminishing the importance of buoyancy production for the determination of ra
Image Registration of In Vivo Micro-Ultrasound and Ex Vivo Pseudo-Whole Mount Histopathology Images of the Prostate: A Proof-of-Concept Study
Early diagnosis of prostate cancer significantly improves a patient's 5-year
survival rate. Biopsy of small prostate cancers is improved with image-guided
biopsy. MRI-ultrasound fusion-guided biopsy is sensitive to smaller tumors but
is underutilized due to the high cost of MRI and fusion equipment.
Micro-ultrasound (micro-US), a novel high-resolution ultrasound technology,
provides a cost-effective alternative to MRI while delivering comparable
diagnostic accuracy. However, the interpretation of micro-US is challenging due
to subtle gray scale changes indicating cancer vs normal tissue. This challenge
can be addressed by training urologists with a large dataset of micro-US images
containing the ground truth cancer outlines. Such a dataset can be mapped from
surgical specimens (histopathology) onto micro-US images via image
registration. In this paper, we present a semi-automated pipeline for
registering in vivo micro-US images with ex vivo whole-mount histopathology
images. Our pipeline begins with the reconstruction of pseudo-whole-mount
histopathology images and a 3-dimensional (3D) micro-US volume. Each
pseudo-whole-mount histopathology image is then registered with the
corresponding axial micro-US slice using a two-stage approach that estimates an
affine transformation followed by a deformable transformation. We evaluated our
registration pipeline using micro-US and histopathology images from 18 patients
who underwent radical prostatectomy. The results showed a Dice coefficient of
0.94 and a landmark error of 2.7 mm, indicating the accuracy of our
registration pipeline. This proof-of-concept study demonstrates the feasibility
of accurately aligning micro-US and histopathology images. To promote
transparency and collaboration in research, we will make our code and dataset
publicly available
The global oscillation network group site survey. II. Results
The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile.
Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses.
The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum
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