3,023 research outputs found
Power mismatch and civil conflict: an empirical investigation
This paper empirically shows that the imbalance between an ethnic group’s political
and military power is crucial to understanding the likelihood that such a group engages in a conflict. We develop a novel measure of a group’s military power by combining machine learning techniques with rich data on ethnic group characteristics and outcomes of civil conflicts in Africa and the Middle East. We couple this measure with available indicators of an ethnic group’s political power as well as with a novel proxy based on information about the ethnicity of cabinet members. We find that groups characterized by a higher mismatch between military and political power are between 30% and 50% more likely to engage in a conflict against their government depending on the specification used. We also find that the effects of power mismatch are nonlinear, which is in agreement with the predictions of a simple model that accounts for the cost of conflict. Moreover, our results suggest that high-mismatched groups are typically involved in larger and centrist conflicts. The policy implication is that powersharing recommendations and institutional design policies for peace should consider primarily the reduction of power mismatches between relevant groups, rather than focusing exclusively on equalizing political power in isolation
MolFM: A Multimodal Molecular Foundation Model
Molecular knowledge resides within three different modalities of information
sources: molecular structures, biomedical documents, and knowledge bases.
Effective incorporation of molecular knowledge from these modalities holds
paramount significance in facilitating biomedical research. However, existing
multimodal molecular foundation models exhibit limitations in capturing
intricate connections between molecular structures and texts, and more
importantly, none of them attempt to leverage a wealth of molecular expertise
derived from knowledge graphs. In this study, we introduce MolFM, a multimodal
molecular foundation model designed to facilitate joint representation learning
from molecular structures, biomedical texts, and knowledge graphs. We propose
cross-modal attention between atoms of molecular structures, neighbors of
molecule entities and semantically related texts to facilitate cross-modal
comprehension. We provide theoretical analysis that our cross-modal
pre-training captures local and global molecular knowledge by minimizing the
distance in the feature space between different modalities of the same
molecule, as well as molecules sharing similar structures or functions. MolFM
achieves state-of-the-art performance on various downstream tasks. On
cross-modal retrieval, MolFM outperforms existing models with 12.13% and 5.04%
absolute gains under the zero-shot and fine-tuning settings, respectively.
Furthermore, qualitative analysis showcases MolFM's implicit ability to provide
grounding from molecular substructures and knowledge graphs. Code and models
are available on https://github.com/BioFM/OpenBioMed.Comment: 31 pages, 15 figures, and 15 table
Empowering AI drug discovery with explicit and implicit knowledge
Motivation: Recently, research on independently utilizing either explicit
knowledge from knowledge graphs or implicit knowledge from biomedical
literature for AI drug discovery has been growing rapidly. These approaches
have greatly improved the prediction accuracy of AI models on multiple
downstream tasks. However, integrating explicit and implicit knowledge
independently hinders their understanding of molecules. Results: We propose
DeepEIK, a unified deep learning framework that incorporates both explicit and
implicit knowledge for AI drug discovery. We adopt feature fusion to process
the multi-modal inputs, and leverage the attention mechanism to denoise the
text information. Experiments show that DeepEIK significantly outperforms
state-of-the-art methods on crucial tasks in AI drug discovery including
drug-target interaction prediction, drug property prediction and
protein-protein interaction prediction. Further studies show that benefiting
from explicit and implicit knowledge, our framework achieves a deeper
understanding of molecules and shows promising potential in facilitating drug
discovery applications.Comment: Bioinformatic
LAMP: a micro-satellite based soft X-ray polarimeter for astrophysics
The Lightweight Asymmetry and Magnetism Probe (LAMP) is a micro-satellite
mission concept dedicated for astronomical X-ray polarimetry and is currently
under early phase study. It consists of segmented paraboloidal multilayer
mirrors with a collecting area of about 1300 cm^2 to reflect and focus 250 eV
X-rays, which will be detected by position sensitive detectors at the focal
plane. The primary targets of LAMP include the thermal emission from the
surface of pulsars and synchrotron emission produced by relativistic jets in
blazars. With the expected sensitivity, it will allow us to detect polarization
or place a tight upper limit for about 10 pulsars and 20 blazars. In addition
to measuring magnetic structures in these objects, LAMP will also enable us to
discover bare quark stars if they exist, whose thermal emission is expected to
be zero polarized, while the thermal emission from neutron stars is believed to
be highly polarized due to plasma polarization and the quantum electrodynamics
(QED) effect. Here we present an overview of the mission concept, its science
objectives and simulated observational results
Mutual Funds and Information Diffusion: The Role of Country-Level Governance
__Abstract__
We hypothesize that poor country-level governance, which makes public information less reliable, induces fund managers to increase their use of semi-public information. Utilizing data from international mutual funds and stocks over the 2000-2009 period, we find that semi-public information-related stock rebalancing can be five times higher in countries with the worst quality of governance than in countries with the best. The use of semi-public information increases price informativeness but also increases information asymmetry and reduces stock liquidity. It also intensifies the price impact and liquidity crunch during the recent global financial crisis
Protection against alcohol-induced neuronal and cognitive damage by the PPARγ receptor agonist pioglitazone
Binge alcohol drinking has emerged as a typical phenomenon in young people. This pattern of drinking, repeatedly leading to extremely high blood and brain alcohol levels and intoxication is associated with severe risks of neurodegeneration and cognitive damage. Mechanisms involved in excitotoxicity and neuroinflammation are pivotal elements in alcohol-induced neurotoxicity. Evidence has demonstrated that PPARγ receptor activation shows anti-inflammatory and neuroprotective properties. Here we examine whether treatment with the PPARγ agonist pioglitazone is beneficial in counteracting neurodegeneration, neuroinflammation and cognitive damage produced by binge alcohol intoxication. Adult Wistar rats were subjected to a 4-day binge intoxication procedure, which is commonly used to model excessive alcohol consumption in humans. Across the 4-day period, pioglitazone (0, 30, 60mg/kg) was administered orally twice daily at 12-h intervals. Degenerative cells were detected by fluoro-jade B (FJ-B) immunostaining in brain regions where expression of pro-inflammatory cytokines was also determined. The effects of pioglitazone on cognitive function were assessed in an operant reversal learning task and the Morris water maze task. Binge alcohol exposure produced selective neuronal degeneration in the hippocampal dentate gyrus and the adjacent entorhinal cortex. Pioglitazone reduced FJ-B positive cells in both regions and prevented alcohol-induced expression of pro-inflammatory cytokines. Pioglitazone also rescued alcohol-impaired reversal learning in the operant task and spatial learning deficits in the Morris water maze. These findings demonstrate that activation of PPARγ protects against neuronal and cognitive degeneration elicited by binge alcohol exposure. The protective effect of PPARγ agonist appears to be linked to inhibition of pro-inflammatory cytokines
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