1,440 research outputs found
Learning to Decompose Visual Features with Latent Textual Prompts
Recent advances in pre-training vision-language models like CLIP have shown
great potential in learning transferable visual representations. Nonetheless,
for downstream inference, CLIP-like models suffer from either 1) degraded
accuracy and robustness in the case of inaccurate text descriptions during
retrieval-based inference (the challenge for zero-shot protocol); or 2)
breaking the well-established vision-language alignment (the challenge for
linear probing). To address them, we propose Decomposed Feature Prompting
(DeFo). DeFo leverages a flexible number of learnable embeddings as textual
input while maintaining the vision-language dual-model architecture, which
enables the model to learn decomposed visual features with the help of
feature-level textual prompts. We further use an additional linear layer to
perform classification, allowing a scalable size of language inputs. Our
empirical study shows DeFo's significance in improving the vision-language
models. For example, DeFo obtains 73.2% test accuracy on ImageNet with a
ResNet-50 backbone without tuning any pretrained weights of both the vision and
language encoder, outperforming zero-shot CLIP by a large margin of 15.0%, and
outperforming state-of-the-art vision-language prompt tuning method by 7.6%
Stormiest winter on record for Ireland and UK
Meteorological agencies of Ireland and the UK have confirmed that winter (December to
February) 2013-14 (W2013/14) set records for precipitation totals and the occurrence of
extreme wind speeds1,2,3. Less clear is whether storminess (characterised as the frequency
and intensity of cyclones) during W2013/14 was equally unprecedented. We assess multidecadal
variations in storminess by considering frequency and intensity together and find
that W2013/14 was indeed exceptional. Given the potential societal impacts there is clearly
a need to better understand the processes driving extreme cyclonic activity in the North
Atlantic (NA)
Prognostic value of lymph node ratio in patients with pathological N1 non-small cell lung cancer: A systematic review with meta-analysis
Background: Non-small cell lung cancer (NSCLC) patients with N1 disease have variable outcomes, and additional prognostic factors are needed. The number of positive lymph nodes (LNs) has been proposed as a prognostic indicator. However, the number of positive LNs depends on the number of LNs examined from the resection specimen. The lymph node ratio (LNR) can circumvent this limitation. The purpose of this study is to evaluate LNR as a predictor of survival and recurrence in patients with pathologic N1 NSCLC. Methods: We systematically reviewed studies published before March 17, 2016, on the prognostic value of LNR in patients with pathologic N1 NSCLC. The hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to combine the data. We also evaluated heterogeneity and publication bias. Results: Five studies published between 2010 and 2014 were eligible for this systematic review with metaanalysis. The total number of patients included was 6,130 ranging from 75 to 4,004 patients per study. The combined HR for all eligible studies evaluating the overall survival (OS) and disease-free survival (DFS) of N1 LNR in patients with pathologic N1 NSCLC was 1.53 (95% CI: 1.22-1.85) and 1.64 (95% CI: 1.19-2.09), respectively. We found no heterogeneity and publication bias between the reports. Conclusions: LNR is a worthy predictor of survival and cancer recurrence in patients with pathological N1 NSCLC
Fluoroquinolones and isoniazid-resistant tuberculosis: implications for the 2018 WHO guidance.
INTRODUCTION: 2018 World Health Organization (WHO) guidelines for the treatment of isoniazid (H)-resistant (Hr) tuberculosis recommend a four-drug regimen: rifampicin (R), ethambutol (E), pyrazinamide (Z) and levofloxacin (Lfx), with or without H ([H]RZE-Lfx). This is used once Hr is known, such that patients complete 6 months of Lfx (≥6[H]RZE-6Lfx). This cohort study assessed the impact of fluoroquinolones (Fq) on treatment effectiveness, accounting for Hr mutations and degree of phenotypic resistance. METHODS: This was a retrospective cohort study of 626 Hr tuberculosis patients notified in London, 2009-2013. Regimens were described and logistic regression undertaken of the association between regimen and negative regimen-specific outcomes (broadly, death due to tuberculosis, treatment failure or disease recurrence). RESULTS: Of 594 individuals with regimen information, 330 (55.6%) were treated with (H)RfZE (Rf=rifamycins) and 211 (35.5%) with (H)RfZE-Fq. The median overall treatment period was 11.9 months and median Z duration 2.1 months. In a univariable logistic regression model comparing (H)RfZE with and without Fqs, there was no difference in the odds of a negative regimen-specific outcome (baseline (H)RfZE, cluster-specific odds ratio 1.05 (95% CI 0.60-1.82), p=0.87; cluster NHS trust). Results varied minimally in a multivariable model. This odds ratio dropped (0.57, 95% CI 0.14-2.28) when Hr genotype was included, but this analysis lacked power (p=0.42). CONCLUSIONS: In a high-income setting, we found a 12-month (H)RfZE regimen with a short Z duration to be similarly effective for Hr tuberculosis with or without a Fq. This regimen may result in fewer adverse events than the WHO recommendations
Reversible spin-optical interface in luminescent organic radicals
Molecules present a versatile platform for quantum information science, and
are candidates for sensing and computation applications. Robust spin-optical
interfaces are key to harnessing the quantum resources of materials. To date,
carbon-based candidates have been non-luminescent, which prevents optical
read-out. Here we report the first organic molecules displaying both efficient
luminescence and near-unity generation yield of high-spin multiplicity excited
states. This is achieved by designing an energy resonance between emissive
doublet and triplet levels, here on covalently coupled
tris(2,4,6-trichlorophenyl) methyl-carbazole radicals (TTM-1Cz) and anthracene.
We observe the doublet photoexcitation delocalise onto the linked acene within
a few picoseconds and subsequently evolve to a pure high spin state (quartet
for monoradicals, quintet for biradical) of mixed radical-triplet character
near 1.8 eV. These high-spin states are coherently addressable with microwaves
even at 295 K, with optical read-out enabled by intersystem crossing to
emissive states. Furthermore, for the biradical, on return to the ground state
the previously uncorrelated radical spins either side of the anthracene show
strong spin correlation. Our approach simultaneously supports a high efficiency
of initialisation, spin manipulations and light-based read-out at room
temperature. The integration of luminescence and high-spin states creates an
organic materials platform for emerging quantum technologies
Chronic Hepatitis B Virus Infection and Risk of Stroke Types: A Prospective Cohort Study of 500 000 Chinese Adults
BACKGROUND:
Stroke is a leading cause of mortality and permanent disability in China, with large and unexplained geographic variations in rates of different stroke types. Chronic hepatitis B virus infection is prevalent among Chinese adults and may play a role in stroke cause.
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METHODS:
The prospective China Kadoorie Biobank included >500 000 adults aged 30 to 79 years who were recruited from 10 (5 urban and 5 rural) geographically diverse areas of China from 2004 to 2008, with determination of hepatitis B surface antigen (HBsAg) positivity at baseline. During 11 years of follow-up, a total of 59 117 incident stroke cases occurred, including 11 318 intracerebral hemorrhage (ICH), 49 971 ischemic stroke, 995 subarachnoid hemorrhage, and 3036 other/unspecified stroke. Cox regression models were used to estimate adjusted hazard ratios (HRs) for risk of stroke types associated with HBsAg positivity. In a subset of 17 833 participants, liver enzymes and lipids levels were measured and compared by HBsAg status.
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RESULTS:
Overall, 3.0% of participants were positive for HBsAg. HBsAg positivity was associated with an increased risk of ICH (adjusted HR, 1.29 [95% CI, 1.16–1.44]), similarly for fatal (n=5982; adjusted HR, 1.36 [95% CI, 1.16–1.59]) and nonfatal (n=5336; adjusted HR, 1.23 [95% CI, 1.06–1.44]) ICH. There were no significant associations of HBsAg positivity with risks of ischemic stroke (adjusted HR, 0.97 [95% CI, 0.92–1.03]), subarachnoid hemorrhage (adjusted HR, 0.87 [95% CI, 0.57–1.33]), or other/unspecified stroke (adjusted HR, 1.12 [95% CI, 0.89–1.42]). Compared with HBsAg-negative counterparts, HBsAg-positive individuals had lower lipid and albumin levels and higher liver enzyme levels. After adjustment for liver enzymes and albumin, the association with ICH from HBsAg positivity attenuated to 1.15 (0.90–1.48), suggesting possible mediation by abnormal liver function.
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CONCLUSIONS:
Among Chinese adults, chronic hepatitis B virus infection is associated with an increased risk of ICH but not other stroke types, which may be mediated through liver dysfunction and altered lipid metabolism
Narrowband Biphotons: Generation, Manipulation, and Applications
In this chapter, we review recent advances in generating narrowband biphotons
with long coherence time using spontaneous parametric interaction in monolithic
cavity with cluster effect as well as in cold atoms with electromagnetically
induced transparency. Engineering and manipulating the temporal waveforms of
these long biphotons provide efficient means for controlling light-matter
quantum interaction at the single-photon level. We also review recent
experiments using temporally long biphotons and single photons.Comment: to appear as a book chapter in a compilation "Engineering the
Atom-Photon Interaction" published by Springer in 2015, edited by A.
Predojevic and M. W. Mitchel
Two-Dimensional Lattice Boltzmann Model For Compressible Flows With High Mach Number
In this paper we present an improved lattice Boltzmann model for compressible
Navier-Stokes system with high Mach number. The model is composed of three
components: (i) the discrete-velocity-model by Watari and Tsutahara [Phys Rev E
\textbf{67},036306(2003)], (ii) a modified Lax-Wendroff finite difference
scheme where reasonable dissipation and dispersion are naturally included,
(iii) artificial viscosity. The improved model is convenient to compromise the
high accuracy and stability. The included dispersion term can effectively
reduce the numerical oscillation at discontinuity. The added artificial
viscosity helps the scheme to satisfy the von Neumann stability condition.
Shock tubes and shock reflections are used to validate the new scheme. In our
numerical tests the Mach numbers are successfully increased up to 20 or higher.
The flexibility of the new model makes it suitable for tracking shock waves
with high accuracy and for investigating nonlinear nonequilibrium complex
systems
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