2,114 research outputs found
Shadow Cones: Unveiling Partial Orders in Hyperbolic Space
Hyperbolic space has been shown to produce superior low-dimensional
embeddings of hierarchical structures that are unattainable in Euclidean space.
Building upon this, the entailment cone formulation of Ganea et al. uses
geodesically convex cones to embed partial orderings in hyperbolic space.
However, these entailment cones lack intuitive interpretations due to their
definitions via complex concepts such as tangent vectors and the exponential
map in Riemannian space. In this paper, we present shadow cones, an innovative
framework that provides a physically intuitive interpretation for defining
partial orders on general manifolds. This is achieved through the use of
metaphoric light sources and object shadows, inspired by the sun-earth-moon
relationship. Shadow cones consist of two primary classes: umbral and penumbral
cones. Our results indicate that shadow cones offer robust representation and
generalization capabilities across a variety of datasets, such as WordNet and
ConceptNet, thereby outperforming the top-performing entailment cones. Our
findings indicate that shadow cones offer an innovative, general approach to
geometrically encode partial orders, enabling better representation and
analysis of datasets with hierarchical structures
Coneheads: Hierarchy Aware Attention
Attention networks such as transformers have achieved state-of-the-art
performance in many domains. These networks rely heavily on the dot product
attention operator, which computes the similarity between two points by taking
their inner product. However, the inner product does not explicitly model the
complex structural properties of real world datasets, such as hierarchies
between data points. To remedy this, we introduce cone attention, a drop-in
replacement for dot product attention based on hyperbolic entailment cones.
Cone attention associates two points by the depth of their lowest common
ancestor in a hierarchy defined by hyperbolic cones, which intuitively measures
the divergence of two points and gives a hierarchy aware similarity score. We
test cone attention on a wide variety of models and tasks and show that it
improves task-level performance over dot product attention and other baselines,
and is able to match dot-product attention with significantly fewer parameters.
Our results suggest that cone attention is an effective way to capture
hierarchical relationships when calculating attention
Economic factors influencing zoonotic disease dynamics: demand for poultry meat and seasonal transmission of avian influenza in Vietnam
While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods-wavelet analysis, economic analysis, statistical and disease transmission modelling-we aimed to explore the influence of climatic and economic factors on the seasonality of H5N1 Highly Pathogenic Avian Influenza in the domestic poultry population of Vietnam. We found that while climatic variables are associated with seasonal variation in the incidence of avian influenza outbreaks in the North of the country, this is not the case in the Centre and the South. In contrast, temporal patterns of H5N1 incidence are similar across these 3 regions: periods of high H5N1 incidence coincide with Lunar New Year festival, occurring in January-February, in the 3 climatic regions for 5 out of the 8 study years. Yet, daily poultry meat consumption drastically increases during Lunar New Year festival throughout the country. To meet this rise in demand, poultry production and trade are expected to peak around the festival period, promoting viral spread, which we demonstrated using a stochastic disease transmission model. This study illustrates the way in which economic factors may influence the dynamics of livestock pathogens
Construção de perfis genéticos com o uso de marcadores moleculares SSR.
Por meio da proteção de cultivares, é possível assegurar que investimentos empregados no desenvolvimento de novas variedades sejam reaplicados em programas de melhoramento genético, garantindo sua longevidade. A ficha de descritores de videira, usada pelo Serviço Nacional de Proteção de Cultivares- Ministério da Agricultura, Pecuária e Abastecimento (SNPCMAPA), muitas vezes, inclui cultivares-exemplo que não são cultivadas, nem conhecidas no Brasil
Aspirin and extended-release dipyridamole versus clopidogrel for recurrent stroke
Background
Recurrent stroke is a frequent, disabling event after ischemic stroke. This study compared
the efficacy and safety of two antiplatelet regimens — aspirin plus extendedrelease
dipyridamole (ASA–ERDP) versus clopidogrel.
Methods
In this double-blind, 2-by-2 factorial trial, we randomly assigned patients to receive
25 mg of aspirin plus 200 mg of extended-release dipyridamole twice daily or to receive
75 mg of clopidogrel daily. The primary outcome was first recurrence of stroke.
The secondary outcome was a composite of stroke, myocardial infarction, or death
from vascular causes. Sequential statistical testing of noninferiority (margin of 1.075),
followed by superiority testing, was planned.
Results
A total of 20,332 patients were followed for a mean of 2.5 years. Recurrent stroke
occurred in 916 patients (9.0%) receiving ASA–ERDP and in 898 patients (8.8%) receiving
clopidogrel (hazard ratio, 1.01; 95% confidence interval [CI], 0.92 to 1.11). The
secondary outcome occurred in 1333 patients (13.1%) in each group (hazard ratio for
ASA–ERDP, 0.99; 95% CI, 0.92 to 1.07). There were more major hemorrhagic events
among ASA–ERDP recipients (419 [4.1%]) than among clopidogrel recipients (365
[3.6%]) (hazard ratio, 1.15; 95% CI, 1.00 to 1.32), including intracranial hemorrhage
(hazard ratio, 1.42; 95% CI, 1.11 to 1.83). The net risk of recurrent stroke or major
hemorrhagic event was similar in the two groups (1194 ASA–ERDP recipients [11.7%],
vs. 1156 clopidogrel recipients [11.4%]; hazard ratio, 1.03; 95% CI, 0.95 to 1.11).
Conclusions
The trial did not meet the predefined criteria for noninferiority but showed similar rates
of recurrent stroke with ASA–ERDP and with clopidogrel. There is no evidence that either
of the two treatments was superior to the other in the prevention of recurrent
stroke. (ClinicalTrials.gov number, NCT00153062.
A False Start in the Race Against Doping in Sport: Concerns With Cycling’s Biological Passport
Professional cycling has suffered from a number of doping scandals. The sport’s governing bodies have responded by implementing an aggressive new antidoping program known as the biological passport. Cycling’s biological passport marks a departure from traditional antidoping efforts, which have focused on directly detecting prohibited substances in a cyclist’s system. Instead, the biological passport tracks biological variables in a cyclist’s blood and urine over time, monitoring for fluctuations that are thought to indirectly reveal the effects of doping. Although this method of indirect detection is promising, it also raises serious legal and scientific concerns. Since its introduction, the cycling community has debated the reliability of indirect biological-passport evidence and the clarity, consistency, and transparency of its use in proving doping violations. Such uncertainty undermines the legitimacy of finding cyclists guilty of doping based on this indirect evidence alone. Antidoping authorities should address these important concerns before continuing to pursue doping sanctions against cyclists solely on the basis of their biological passports
Recommended from our members
Genome-wide association study identifies 30 loci associated with bipolar disorder.
Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P < 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P < 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder
- …