138 research outputs found
AutoTransfer: AutoML with Knowledge Transfer -- An Application to Graph Neural Networks
AutoML has demonstrated remarkable success in finding an effective neural
architecture for a given machine learning task defined by a specific dataset
and an evaluation metric. However, most present AutoML techniques consider each
task independently from scratch, which requires exploring many architectures,
leading to high computational cost. Here we propose AutoTransfer, an AutoML
solution that improves search efficiency by transferring the prior
architectural design knowledge to the novel task of interest. Our key
innovation includes a task-model bank that captures the model performance over
a diverse set of GNN architectures and tasks, and a computationally efficient
task embedding that can accurately measure the similarity among different
tasks. Based on the task-model bank and the task embeddings, we estimate the
design priors of desirable models of the novel task, by aggregating a
similarity-weighted sum of the top-K design distributions on tasks that are
similar to the task of interest. The computed design priors can be used with
any AutoML search algorithm. We evaluate AutoTransfer on six datasets in the
graph machine learning domain. Experiments demonstrate that (i) our proposed
task embedding can be computed efficiently, and that tasks with similar
embeddings have similar best-performing architectures; (ii) AutoTransfer
significantly improves search efficiency with the transferred design priors,
reducing the number of explored architectures by an order of magnitude.
Finally, we release GNN-Bank-101, a large-scale dataset of detailed GNN
training information of 120,000 task-model combinations to facilitate and
inspire future research.Comment: ICLR 202
Experimental measurement of dynamic concentration of nanofluid in laminar flow
Nanofluid is thought to have a potential enhancement in heat transfer behaviour of fluid. The nanoparticle concentration in nanofluid is one of the most important factors that affect the nanofluid behaviour. The static concentration was applied in the researches under flowing condition. In this paper, Nuclear Magnetic Resonance (NMR) scanning was applied to study the dynamic concentration of nanofluid flow in pipe. The experiments were carried out with ferrofluid under different concentration and temperature. A new parameter T2* was introduced in the study. Experiments were carried out to obtain the T2* of nanofluid in the pipe. An empirical equation based on T2* and temperature was proposed to calculate the concentration of nanoparticles. Then, experiments were carried out with flowing ferrofluid in pipe. The dynamic concentration was calculated with the empirical equation. It has a highest concentration near the pipe wall. The concentration decreases from the wall to the pipe centre. Furthermore, the experiment result also gives out a chance to investigate the mechanism of nanoparticle movement in laminar flow with the concentration gradient along radius
Prognostic implication of p27Kip1, Skp2 and Cks1 expression in renal cell carcinoma: a tissue microarray study
<p>Abstract</p> <p>Background</p> <p>p27<sup>Kip1 </sup>plays a major role as a negative regulator of the cell cycle. The regulation of p27<sup>Kip1 </sup>degradation is mediated by its specific ubiquitin ligase subunits S-phase kinase protein (Skp) 2 and cyclin-dependent kinase subunit (Cks) 1. However, little is known regarding the prognostic utility of p27<sup>Kip1</sup>, Skp2 and Cks1 expression in renal cell carcinoma.</p> <p>Methods</p> <p>Immunohistochemistry was performed for p27<sup>Kip1</sup>, Skp2 and Cks1 in tissue microarrays of 482 renal cell carcinomas with follow-up. The data were correlated with clinicopathological features. The univariate and multivariate survival analyses were also performed to determine their prognostic significance.</p> <p>Results</p> <p>Immunoreactivity of p27<sup>Kip1</sup>, Skp2 and Cks1 was noted in 357, 71 and 82 patients, respectively. Skp2 and Cks1 expression were not noted in chromophobe cancers. A strong correlation was found between Skp2 and Cks1 expression (P < 0.001), both of which were inversely related to p27<sup>Kip1 </sup>levels (P = 0.006 and P < 0.001), especially in primary and clear-cell cancers. Low p27<sup>Kip1 </sup>expression and Skp2 expression were correlated with larger tumor size and higher stage, as well as tumor necrosis. Cks1 expression was only correlated with tumor size. In univariate analysis, low p27<sup>Kip1 </sup>expression, Skp2 and Cks1 expression were all associated with a poor prognosis, while in multivariate analysis, only low p27<sup>Kip1 </sup>expression were independent prognostic factors for both cancer specific survival and recurrence-free survival in patients with RCC.</p> <p>Conclusion</p> <p>Our results suggest that immunohistochemical expression levels of p27<sup>Kip1</sup>, Skp2 and Cks1 may serve as markers with prognostic value in renal cell carcinoma.</p
Bionic inspired study of heat pipe from plant water migration
Heat pipe is well regarded as super thermal conductor and has a wide range of applications in the variety of industry sections. A great number of researches have been done on enhancing the performance of heat pipe through improving the flow pattern. The research on plant water migration based on bionic engineering approach provides a very interesting path to the fluid flow enhancement inside heat pipe, and improvement of inner structure as well. The main forces that drive the water migrates in plants are capillary effect, friction, gravity and transpiration effect, and which are also the main driven forces in heat pipe. Although most researches on heat pipe focus on capillary effect against gravity, transpiration effect is still very important as dragging force occurs when water evaporates. And all these can be investigated through plant water migration. A mathematical model describing the water migration process in plant is proposed in this paper. And the result obtained from mathematical calculation is compared with the experimental measured result using Nuclear Magnetic Resonance (NMR) technology. The perfect matching between the two results confirmed the possibility of using the mathematical model to analyze fluid flow in micro channels, including heat pipe. And it also successfully put transpiration effect and friction into consideration, which give out a clearer view of the forces inside heat pipe for further research
Case report: Sarcomatoid urothelial carcinoma of the renal pelvis masquerading as a renal abscess
Sarcomatoid urothelial carcinoma (SUC), a rare tumor of the urinary tract epithelium, exhibits a high degree of malignancy and therefore a poor prognosis. Due to the absence of specific clinical presentations and imaging findings, SUC of the renal pelvis masquerades as a renal abscess is frequently under-recognized or misdiagnosed as benign inflammatory disease, resulting in delayed or erroneous treatment. Here, we report a patient with SUC of the renal pelvis who presented with a renal abscess. Repeated anti-inflammatory treatment was ineffective. Unexpectedly, cancerous cells were detected in subsequent exfoliative cytology of nephrostomy drainage fluid. In accordance with this, radical surgery and postoperative chemotherapy were conducted. Fortunately, neither recurrence nor metastasis occurred during a one-year follow-up
Discovery of electromagnetic polarization in Asian rice wine deterioration process and its applications
Rice wine, known as yellow wine in China and Japan, possesses considerable nutritional value and holds significant global influence. This study addresses the challenge of preserving rice wine, which is prone to rancidity due to its low alcohol content. Conventional storage techniques employing pottery jars often result in substantial spoilage losses. Through rigorous investigation, this research identifies a polarization phenomenon exhibited by degraded rice wine when subjected to high-frequency microwaves(>60GHz), presenting a pioneering method for detecting spoilage, even within sealed containers. Employing a multi-channel microwave radar apparatus, the study delves into the susceptibility of rice wine to electromagnetic waves across various frequencies, uncovering pronounced polarization traits in deteriorated samples within the E-band microwave spectrum. Furthermore, lab-controlled simulations elucidate a direct correlation between physicochemical alterations and high-frequency Radar Cross Section (RCS) signals during the wine’s deterioration process. A novel six-membered Hydrated Cluster hypothesis is proposed, offering insights into the molecular mechanisms underlying this phenomenon. Additionally, dielectric property assessments conducted using vector network analyzers (VNA) reveal noteworthy enhancements in the dielectric constant of deteriorated rice wine, particularly within the high-frequency domain, thereby augmenting detectability. These findings carry implications for refining rice wine preservation techniques and contribute to the advancement of non-destructive testing technologies, enabling the detection of rice wine deterioration or indications thereof, even within sealed vessels
The Development and Application of a Dot-ELISA Assay for Diagnosis of Southern Rice Black-Streaked Dwarf Disease in the Field
Outbreaks of the southern rice black-streaked dwarf virus (SRBSDV) have caused significant crop losses in southern China in recent years, especially in 2010. There are no effective, quick and practicable methods for the diagnosis of rice dwarf disease that can be used in the field. Traditional reverse transcription-polymerase chain reaction (RT-PCR) methodology is accurate but requires expensive reagents and instruments, as well as complex procedures that limit its applicability for field tests. To develop a sensitive and reliable assay for routine laboratory diagnosis, a rapid dot enzyme-linked immunosorbent assay (dot-ELISA) method was developed for testing rice plants infected by SRBSDV. Based on anti-SRBSDV rabbit antiserum, this new dot-ELISA was highly reliable, sensitive and specific toward SRBSDV. The accuracy of two blotting media, polyvinylidene fluoride membrane (PVDF membrane) and nitrocellulose filter membrane (NC membrane), was compared. In order to facilitate the on-site diagnosis, three county laboratories were established in Shidian (Yunnan province), Jianghua (Hunan Province) and Libo (Guizhou province). Suspected rice cases from Shidian, Yuanjiang and Malipo in Yunnan province were tested and some determined to be positive for SRBSDV by the dot-ELISA and confirmed by the One Step RT-PCR method. To date, hundreds of suspected rice samples collected from 61 districts in southwestern China have been tested, among which 55 districts were found to have rice crops infected by SRBSDV. Furthermore, the test results in the county laboratories showed that Libo, Dehong (suspected samples were sent to Shidian) and Jianghua were experiencing a current SRBSDV outbreak
Widespread occurrence of distinct alkenones from Group I haptophytes in freshwater lakes: Implications for paleotemperature and paleoenvironmental reconstructions
Alkenones are C35-C42 polyunsaturated ketone lipids that are commonly employed to reconstruct changes in sea surface temperature. However, their use in coastal seas and saline lakes can be hindered by species-mixing effects. We recently hypothesized that freshwater lakes are immune to species-mixing effects because they appear to exclusively host Group I haptophyte algae, which produce a distinct distribution of alkenones with a relatively consistent response of alkenone unsaturation to temperature. To evaluate this hypothesis and explore the geographic extent of Group I haptophytes, we analyzed alkenones in sediment and suspended particulate matter samples from lakes distributed throughout the mid- and high latitudes of the Northern Hemisphere (n = 30). Our results indicate that Group I-type alkenone distributions are widespread in freshwater lakes from a range of different climates (mean annual air temperature range: -17.3-10.9 degrees C; mean annual precipitation range: 125-1657 mm yr(-1); latitude range: 40-81 degrees N), and are commonly found in neutral to basic lakes (pH > 7.0), including volcanic lakes and lakes with mafic bedrock. We show that these freshwater lakes do not feature alkenone distributions characteristic of Group II lacustrine haptophytes, providing support for the hypothesis that freshwater lakes are immune to species-mixing effects. In lakes that underwent temporal shifts in salinity, we observed mixed Group I/II alkenone distributions and the alkenone contributions from each group could be quantified with the RIK37 index. Additionally, we observed significant correlations of alkenone unsaturation (U-37(K)) with seasonal and mean annual air temperature with this expanded freshwater lakes dataset, with the strongest correlation occurring during the spring transitional season (U-37(K) = 0.029 * T - 0.49; r(2) = 0.60; p < 0.0001). We present new sediment trap data from two lakes in northern Alaska (Toolik Lake, 68.632 degrees N, 149.602 degrees W; lake E5, 68.643 degrees N, 149.458 degrees W) that demonstrate the highest sedimentary fluxes of alkenones in the spring transitional season, concurrent with the period of lake ice melt and isothermal mixing. Together, these data provide a framework for evaluating lacustrine alkenone distributions and utilizing alkenone unsaturation as a lake temperature proxy. (C) 2018 Elsevier B.V. All rights reserved
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