233 research outputs found
Environmental problems induced by the thermal discharges from the power plant (Chinese progress in thermal effects studies)
Article信州大学理学部附属諏訪臨湖実験所報告 9: 95-99(1995)departmental bulletin pape
Active inductor shunt peaking in high-speed VCSEL driver design
An all transistor active inductor shunt peaking structure has been used in a
prototype of 8-Gbps high-speed VCSEL driver which is designed for the optical
link in ATLAS liquid Argon calorimeter upgrade. The VCSEL driver is fabricated
in a commercial 0.25-um Silicon-on-Sapphire (SoS) CMOS process for radiation
tolerant purpose. The all transistor active inductor shunt peaking is used to
overcome the bandwidth limitation from the CMOS process. The peaking structure
has the same peaking effect as the passive one, but takes a small area, does
not need linear resistors and can overcome the process variation by adjust the
peaking strength via an external control. The design has been tapped out, and
the prototype has been proofed by the preliminary electrical test results and
bit error ratio test results. The driver achieves 8-Gbps data rate as simulated
with the peaking. We present the all transistor active inductor shunt peaking
structure, simulation and test results in this paper.Comment: 4 pages, 6 figures and 1 table, Submitted to 'Chinese Physics C
Deep Graph Neural Networks via Flexible Subgraph Aggregation
Graph neural networks (GNNs), a type of neural network that can learn from
graph-structured data and learn the representation of nodes through aggregating
neighborhood information, have shown superior performance in various downstream
tasks. However, it is known that the performance of GNNs degrades gradually as
the number of layers increases. In this paper, we evaluate the expressive power
of GNNs from the perspective of subgraph aggregation. We reveal the potential
cause of performance degradation for traditional deep GNNs, i.e., aggregated
subgraph overlap, and we theoretically illustrate the fact that previous
residual-based GNNs exploit the aggregation results of 1 to hop subgraphs
to improve the effectiveness. Further, we find that the utilization of
different subgraphs by previous models is often inflexible. Based on this, we
propose a sampling-based node-level residual module (SNR) that can achieve a
more flexible utilization of different hops of subgraph aggregation by
introducing node-level parameters sampled from a learnable distribution.
Extensive experiments show that the performance of GNNs with our proposed SNR
module outperform a comprehensive set of baselines
Text Is All You Need: Learning Language Representations for Sequential Recommendation
Sequential recommendation aims to model dynamic user behavior from historical
interactions. Existing methods rely on either explicit item IDs or general
textual features for sequence modeling to understand user preferences. While
promising, these approaches still struggle to model cold-start items or
transfer knowledge to new datasets. In this paper, we propose to model user
preferences and item features as language representations that can be
generalized to new items and datasets. To this end, we present a novel
framework, named Recformer, which effectively learns language representations
for sequential recommendation. Specifically, we propose to formulate an item as
a "sentence" (word sequence) by flattening item key-value attributes described
by text so that an item sequence for a user becomes a sequence of sentences.
For recommendation, Recformer is trained to understand the "sentence" sequence
and retrieve the next "sentence". To encode item sequences, we design a
bi-directional Transformer similar to the model Longformer but with different
embedding layers for sequential recommendation. For effective representation
learning, we propose novel pretraining and finetuning methods which combine
language understanding and recommendation tasks. Therefore, Recformer can
effectively recommend the next item based on language representations.
Extensive experiments conducted on six datasets demonstrate the effectiveness
of Recformer for sequential recommendation, especially in low-resource and
cold-start settings.Comment: accepted to KDD 202
Golgi Apparatus-Localized Synaptotagmin 2 Is Required for Unconventional Secretion in Arabidopsis
BACKGROUND: Most secretory proteins contain signal peptides that direct their sorting to the ER and secreted via the conventional ER/Golgi transport pathway, while some signal-peptide-lacking proteins have been shown to export through ER/Golgi independent secretory pathways. Hygromycin B is an aminoglycoside antibiotic produced by Streptomyces hygroscopicus that is active against both prokaryotic and eukaryotic cells. The hygromycin phosphotransferase (HYG(R)) can phosphorylate and inactivate the hygromycin B, and has been widely used as a positive selective marker in the construction of transgenic plants. However, the localization and trafficking of HYG(R) in plant cells remain unknown. Synaptotagmins (SYTs) are involved in controlling vesicle endocytosis and exocytosis as calcium sensors in animal cells, while their functions in plant cells are largely unclear. METHODOLOGY/PRINCIPAL FINDINGS: We found Arabidopsis synaptotagmin SYT2 was localized on the Golgi apparatus by immunofluorescence and immunogold labeling. Surprisingly, co-expression of SYT2 and HYG(R) caused hypersensitivity of the transgenic Arabidopsis plants to hygromycin B. HYG(R), which lacks a signal sequence, was present in the cytoplasm as well as in the extracellular space in HYG(R)-GFP transgenic Arabidopsis plants and its secretion is not sensitive to brefeldin A treatment, suggesting it is not secreted via the conventional secretory pathway. Furthermore, we found that HYG(R)-GFP was truncated at carboxyl terminus of HYG(R) shortly after its synthesis, and the cells deficient SYT2 failed to efficiently truncate HYG(R)-GFP,resulting in HYG(R)-GFP accumulated in prevacuoles/vacuoles, indicating that SYT2 was involved in HYG(R)-GFP trafficking and secretion. CONCLUSION/SIGNIFICANCE: These findings reveal for the first time that SYT2 is localized on the Golgi apparatus and regulates HYG(R)-GFP secretion via the unconventional protein transport from the cytosol to the extracelluar matrix in plant cells
Low Loss and Magnetic Field-tuned Superconducting THz Metamaterial
Superconducting terahertz (THz) metamaterial (MM) made from superconducting
Nb film has been investigated using a continuous-wave THz spectroscopy with a
superconducting split-coil magnet. The obtained quality factors of the resonant
modes at 132 GHz and 450 GHz are about three times as large as those calculated
for a metal THz MM operating at 1 K, which indicates that superconducting THz
MM is a very nice candidate to achieve low loss performance. In addition, the
magnetic field-tuning on superconducting THz MM is also demonstrated, which
offer an alternative tuning method apart from the existed electric, optical and
thermal tuning on THz MM
Downregulation of RPL6 by siRNA Inhibits Proliferation and Cell Cycle Progression of Human Gastric Cancer Cell Lines
Our previous study revealed that human ribosomal protein L6 (RPL6) was up-regulated in multidrug-resistant gastric cancer cells and over-expression of RPL6 could protect gastric cancer from drug-induced apoptosis. It was further demonstrated that up-regulation of RPL6 accelerated growth and enhanced in vitro colony forming ability of GES cells while down-regulation of RPL6 exhibited the opposite results. The present study was designed to investigate the potential role of RPL6 in therapy of gastric cancer for clinic. The expression of RPL6 and cyclin E in gastric cancer tissues and normal gastric mucosa was evaluated by immunohistochemisty. It was found that RPL6 and cyclin E were expressed at a higher level in gastric cancer tissues than that in normal gastric mucosa and the two were correlative in gastric cancer. Survival time of postoperative patients was analyzed by Kaplan- Meier analysis and it was found that patients with RPL6 positive expression showed shorter survival time than patients that with RPL6 negative expression. RPL6 was then genetically down-regulated in gastric cancer SGC7901 and AGS cell lines by siRNA. It was demonstrated that down-regulation of RPL6 reduced colony forming ability of gastric cancer cells in vitro and reduced cell growth in vivo. Moreover, down-regulation of RPL6 could suppress G1 to S phase transition in these cells. Further, we evidenced that RPL6 siRNA down-regulated cyclin E expression in SGC7901 and AGS cells. Taken together, these data suggested that RPL6 was over-expressed in human gastric tissues and caused poor prognosis. Down-regulation of RPL6 could suppress cell growth and cell cycle progression at least through down-regulating cyclin E and which might be used as a novel approach to gastric cancer therapy
Current Research Problems of Chronic Arsenicosis in China
Chronic arsenicosis is a newly-emerged public-health issue in China and
many other Asian countries. Over 200 million people are estimated to be
at the risk of high arsenic exposure from drinking-water in the Asian
region. To protect people from the hazards of chronic arsenic
poisoning, the Chinese Government has been providing low-arsenic
drinking-water to some seriously-affected rural areas, such as Inner
Mongolia autonomous province. Results of follow-up studies showed that
both the average values of arsenic, including inorganic arsenic (iAs),
monomethylated arsenic, dimethylated arsenic and trimethylated arsenic,
and 8-hydroxydeoxyguanine in urine, decreased significantly after
drinking low-arsenic water for one year, and arsenic-specific skin
lesions also improved to some extent. However, a five-year follow-up
study showed no more significant improvement of skin lesions, while the
potential risk of arsenic-induced cancers after cutting off
high-arsenic exposure was still uncertain and indefinite. The
susceptibility of children compared to adults to chronic arsenic
exposure and the need to re-evaluate the appropriate standard of
arsenic in drinking-water were also discussed in this paper
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