267 research outputs found
Inversion using a new low-dimensional representation of complex binary geological media based on a deep neural network
Efficient and high-fidelity prior sampling and inversion for complex
geological media is still a largely unsolved challenge. Here, we use a deep
neural network of the variational autoencoder type to construct a parametric
low-dimensional base model parameterization of complex binary geological media.
For inversion purposes, it has the attractive feature that random draws from an
uncorrelated standard normal distribution yield model realizations with spatial
characteristics that are in agreement with the training set. In comparison with
the most commonly used parametric representations in probabilistic inversion,
we find that our dimensionality reduction (DR) approach outperforms principle
component analysis (PCA), optimization-PCA (OPCA) and discrete cosine transform
(DCT) DR techniques for unconditional geostatistical simulation of a
channelized prior model. For the considered examples, important compression
ratios (200 - 500) are achieved. Given that the construction of our
parameterization requires a training set of several tens of thousands of prior
model realizations, our DR approach is more suited for probabilistic (or
deterministic) inversion than for unconditional (or point-conditioned)
geostatistical simulation. Probabilistic inversions of 2D steady-state and 3D
transient hydraulic tomography data are used to demonstrate the DR-based
inversion. For the 2D case study, the performance is superior compared to
current state-of-the-art multiple-point statistics inversion by sequential
geostatistical resampling (SGR). Inversion results for the 3D application are
also encouraging
Deformation characteristics and exploration potential of the West Kunlun foreland fold-and-thrust belt
The West Kunlun foreland is dominated by segmented fold-and-thrust belts with significant potential for hydrocarbon exploration, while the extent of exploration in this area has been relatively limited. In this paper, by conducting complex structural interpretation, the geometric and kinematic characteristics, as well as the variations in the segmented fold-and-thrust belts within this region are revealed. The West Kunlun foreland fold-and-thrust belts are divided into three structural segments, which exhibit distinct structural styles. The Pusha-Kedong segment in the east is characterized by large-scale northward propagation, with high-angle basement-involved faults in the root belt and thin-skinned thrusts in the front belt. Additionally, three-row anticlines developed in the middle to the upper structural layers. The Kashi-Yecheng segment, located in the middle, is characterized by strike-slip faults and basement-involved structural wedges transitioning to detachment structures. Within this segment, the Sugaite structure in the mountain front is a wedge structure composed of basement-involved faults and an upper back-thrust fault. Meanwhile, the Yingjisha structure in the thrust front consists of a fold in the lower part and a back-thrust system above it. The lower fold is controlled by the Cambrian detachment thrust, which terminates upward in the Paleogene, while the back-thrust faults truncate upper structural layers and terminate downwards in the Miocene strata. The Wupoer segment in the northwest is controlled by the Main Pamir Thrust and the Front Pamir Thrust, which are low angular forward thrust faults with an arc distribution. A piggyback basin has developed in the root belt and upper structural layer since the Pliocene. Based on the deformation characteristics and the accumulation of oil-gas reservoirs discovered so far, two types of oil and gas-rich thrust belts with different hydrocarbon exploration fields in the West Kunlun foreland are described.Document Type: Original articleCited as: Jiang, L., Dong, H., Li, Y., Zhao, W., Zhang, Y., Bo, D. Deformation characteristics and exploration potential of the West Kunlun foreland fold-and-thrust belt. Advances in Geo-Energy Research, 2024, 11(3): 181-193. https://doi.org/10.46690/ager.2024.03.0
Evidence of a role for prolactin as regulators of ovarian follicular development in goose
Background: Prolactin (PRL) regulates development and reproduction,
and its effects are mediated by the prolactin receptor (PRLR). In order
to clarify the role of PRLR and PRL in the process of follicular
development in the goose ovary, the level of PRLR mRNA expression in
the ovary and follicles of the Sichuan white goose was determined, as
well as the PRL concentration in ovarian follicles. Results: The
level of PRLR mRNA in the hierarchical follicles (HFs) initially
increased, and subsequently decreased, whereas PRLR expressionwas
initially lowand later increased in postovulatory follicles (POFs). The
level of PRLR mRNA expression was the highest in the F4 follicles, and
lowest in the F1 follicles in all of the examined follicles. Compared
with the level of PRLR mRNA expression in the small white follicles
(SWFs), the level of PRLR mRNA was 2.86- and 1.44-fold higher in the F4
and small yellow follicles (SYFs), respectively (P < 0.05). The
level of PRLR mRNA expression in the F4 follicles was highest (P <
0.05) in HFs. The highest PRL concentration in all of the examined
samples was observed in SYFs and F1, with concentration of 6162 mLU/g
and 6197 mLU/g, respectively. The PRL concentration in SYFs was
significantly higher compared with SWFs (P < 0.05). Conclusions:
The change of PRL concentration was similar to the PRLR mRNA expression
level in preovulatory follicles. These results suggest that the PRL
mediated by the PRLR plays a stimulatory role in the SWF to SYF
transition
Learning Cooperative Oversubscription for Cloud by Chance-Constrained Multi-Agent Reinforcement Learning
Oversubscription is a common practice for improving cloud resource
utilization. It allows the cloud service provider to sell more resources than
the physical limit, assuming not all users would fully utilize the resources
simultaneously. However, how to design an oversubscription policy that improves
utilization while satisfying the some safety constraints remains an open
problem. Existing methods and industrial practices are over-conservative,
ignoring the coordination of diverse resource usage patterns and probabilistic
constraints. To address these two limitations, this paper formulates the
oversubscription for cloud as a chance-constrained optimization problem and
propose an effective Chance Constrained Multi-Agent Reinforcement Learning
(C2MARL) method to solve this problem. Specifically, C2MARL reduces the number
of constraints by considering their upper bounds and leverages a multi-agent
reinforcement learning paradigm to learn a safe and optimal coordination
policy. We evaluate our C2MARL on an internal cloud platform and public cloud
datasets. Experiments show that our C2MARL outperforms existing methods in
improving utilization () under different levels of safety
constraints
Diffusion-based Time Series Data Imputation for Microsoft 365
Reliability is extremely important for large-scale cloud systems like
Microsoft 365. Cloud failures such as disk failure, node failure, etc. threaten
service reliability, resulting in online service interruptions and economic
loss. Existing works focus on predicting cloud failures and proactively taking
action before failures happen. However, they suffer from poor data quality like
data missing in model training and prediction, which limits the performance. In
this paper, we focus on enhancing data quality through data imputation by the
proposed Diffusion+, a sample-efficient diffusion model, to impute the missing
data efficiently based on the observed data. Our experiments and application
practice show that our model contributes to improving the performance of the
downstream failure prediction task
Eight-input optical programmable logic array enabled by parallel spectrum modulation
Despite over 40 years' development of optical logic computing, the studies
have been still struggling to support more than four operands, since the high
parallelism of light has not been fully leveraged blocked by the optical
nonlinearity and redundant input modulation in existing methods. Here, we
propose a scalable multi-input optical programmable logic array (PLA) with
minimal logical input, enabled by parallel spectrum modulation. By making full
use of the wavelength resource, an eight-input PLA is experimentally
demonstrated, and there are 2^256 possible combinations of generated logic
gates. Various complex logic fuctions, such as 8-256 decoder, 4-bit comparator,
adder and multiplier are experimentally demonstrated via leveraging the PLA.
The scale of PLA can be further extended by fully using the dimensions of
wavelength and space. As an example, a nine-input PLA is implemented to realize
the two-dimensional optical cellular automaton for the first time and perform
Conway's Game of Life to simulate the evolutionary process of cells. Our work
significantly alleviates the challenge of extensibility of optical logic
devices, opening up new avenues for future large-scale, high-speed and
energy-efficient optical digital computing
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A novel ZRS variant causes preaxial polydactyly type I by increased sonic hedgehog expression in the developing limb bud.
PurposePreaxial polydactyly (PPD) is a common congenital hand malformation classified into four subtypes (PPD I-IV). Variants in the zone of polarizing activity regulatory sequence (ZRS) within intron 5 of the LMBR1 gene are linked to most PPD types. However, the genes responsible for PPD I and the underlying mechanisms are unknown.MethodsA rare large four-generation family with isolated PPD I was subjected to genome-wide genotyping and sequence analysis. In vitro and in vivo functional studies were performed in Caco-2 cells, 293T cells, and a knockin transgenic mouse model.ResultsA novel g.101779T>A (reference sequence: NG_009240.2; position 446 of the ZRS) variant segregates with all PPD I-affected individuals. The knockin mouse with this ZRS variant exhibited PPD I phenotype accompanying ectopic and excess expression of Shh. We confirmed that HnRNP K can bind the ZRS and SHH promoters. The ZRS mutant enhanced the binding affinity for HnRNP K and upregulated SHH expression.ConclusionOur results identify the first PPD I disease-causing variant. The variant leading to PPD I may be associated with enhancing SHH expression mediated by HnRNP K. This study adds to the ZRS-associated syndromes classification system for PPD and clarifies the underlying molecular mechanisms
A STUDY ON ANTICANCER ACTIVITY OF CAULIS SPATHOLOBI EXTRACT ON HUMAN OSTEOSARCOMA SAOS-2 CELLS
The objective of the present study was to investigate the anticancer activity of Chinese medicine Caulis Spatholobi extract on multicentric osteosarcoma cells. Ultraviolet spectrophotometry was used to determine the total flavonoid content in each sample; vanillin sulphuric acid assay was used to determine the condensed tannin content in each sample; and the varying degrees of inhibitory activities of ethanol, ethyl acetate and n-butanol extracts of Caulis Spatholobi on human osteosarcoma Saos-2 cells were studied. The results showed that the inhibitory activity of ethyl acetate extract was the highest among the four extracts. The condensed tannin contents of 1.2 mg/mL Caulis Spatholobi water extract, ethanol extract, ethyl acetate extract and petroleum ether extract were 26.23%, 48.36%, 70.18% and 40.51% respectively; and condensed tannin content of 1.5 mg/mL Caulis Spatholobi water extract, ethanol extract, ethyl acetate extract and petroleum ether extract were 4.15%, 5.81%, 8.76% and 7.30% respectively
Characterization of OAZ1 and its potential functions in goose follicular development
Background: Ornithine decarboxylase antizyme 1 (OAZ1) is an important
regulator of polyamine synthesis and uptake. Our previous studies
indicated that high OAZ1 expression in the ovaries of laying geese is
responsible for poor egg production. In the present study, the
molecular characterization of goose OAZ1 gene was analyzed, as well as
the expression profile in various follicular tissues. Results: An
873-bp cDNA sequence of the OAZ1 gene (Accession No. KC845302) with a
+1 frameshift site (+175T) was obtained. The sequence consisted of a
652-bp two overlapping open reading frames (a putative protein with 216
amino acids). The OAZ domain, OAZ signature and OAZ super family domain
were prominent conserved regions among species. As the follicle size
increased, OAZ1 abundance showed an increasing trend during follicular
development, while it decreased during follicular regression. The level
of OAZ1 mRNA expression was the lowest in the fifth largest
preovulatory follicle, and was 0.65-fold compared to the small white
follicle (P < 0.05). OAZ1 mRNA expression in the largest
preovulatory and postovulatory follicle was 2.11- and 2.49-fold
compared to the small white follicle, respectively (P < 0.05).
Conclusions: The goose OAZ1 structure confirms that OAZ1 plays an
important role in ornithine decarboxylase-mediated regulation of
polyamine homeostasis. Our findings provide an evidence for a potential
function of OAZ1 in follicular development, ovulation and regression
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