214 research outputs found
Temporal Trends and Spatial Variabilities of PCB concentrations in Lake Trout from Lake Superior from 1995 to 2013
It has been frequently reported that concentrations of PCBs in the Great Lakes fish have declined dramatically since their ban on production and use in 1979 in the United States, although some studies suggested that recent rates of decline are leveling off. In order to examine the temporal trends and spatial variabilities of PCB concentrations in lake trout (Salvelinus namaycush) from Lake Superior during the past two decades, statistical analyses were performed on fish sample data collected by two national agencies (U.S. EPA, Environment and Climate Change Canada) and three state agencies (Michigan Department of Environmental Quality, Minnesota Department of Natural Resources, Wisconsin Department of Natural Resources) from both the United States and Canada from 1976 to 2013. Because of a change in PCB analytical methodology in the mid-1990s, intercomparison between data recorded by the previous technique and the improved technique is not feasible.
Because most organochlorine compounds are easily bound to fatty tissues in fish, lipid content has been commonly considered as a predictor of PCB levels. Also, larger fish were assumed to have higher PCBs in their bodies. Multiple linear regression analyses, setting time, lipid content, and fish length as three independent variables, revealed that lipid content had little impact on PCB concentrations at all sites except Whitefish Bay since 1995, which is in contrast to some previous studies. However, a strong positive correlation between PCBs and fish length, in good agreement with previous research, was observed at all sites except Whitefish Bay over the same period.
It has been discovered that PCB concentrations vary among several sampling locations within Lake Superior. The general pattern was that the western sites had significantly higher concentrations than the eastern sites. When the entire historical record was analyzed, temporal trends were evident in all datasets. However, only at Keweenaw Point (U.S. EPA) was significant (p = 0.0005) declining trends in total PCB concentrations observed after 1995. In Wisconsin sites, the declining trend was marginal significant (p = 0.04) during the same period. In other locations, no temporal trends were found but large annual fluctuations occurred for unknown reasons. PCB concentrations at most sites have not achieved the reduction target of 100 ng/g ww for wildlife and human health protection established by the U.S. EPA. It is still difficult to predict when fish will be able to be consumed without limitation in this region
Caustic graphene plasmons with Kelvin angle
A century-long argument made by Lord Kelvin that all swimming objects have an
effective Mach number of 3, corresponding to the Kelvin angle of 19.5 degree
for ship waves, has been recently challenged with the conclusion that the
Kelvin angle should gradually transit to the Mach angle as the ship velocity
increases. Here we show that a similar phenomenon can happen for graphene
plasmons. By analyzing the caustic wave pattern of graphene plasmons stimulated
by a swift charged particle moving uniformly above graphene, we show that at
low velocities of the charged particle, the caustics of graphene plasmons form
the Kelvin angle. At large velocities of the particle, the caustics disappear
and the effective semi-angle of the wave pattern approaches the Mach angle. Our
study introduces caustic wave theory to the field of graphene plasmonics, and
reveals a novel physical picture of graphene plasmon excitation during electron
energy-loss spectroscopy measurement.Comment: 15 pages, 4 figure
A Dynamic Shift-Share Analysis on the China’s R&D: A Structure Analysis
To evaluate the R&D development in China, we can inspect both the R&D expenditure and the research talent pool. In this paper, we analyze the structure of the researcher groups by using dynamic shift-share analysis (DSSA). The DSSA results show that there is still much room to improve in the structure of research group. The provinces/municipalities from eastern China did not perform well in engineering and education researcher groups while the provinces/municipalities from central and western China perform well in engineering, agriculture and education researcher groups. We suggest that the government planners should implement more effective measures to improve the structure of the researcher groups in order to spend the R&D fund wisely and attract more extra fund in R&D
Routing to the Expert: Efficient Reward-guided Ensemble of Large Language Models
The complementary potential of Large Language Models (LLM) assumes
off-the-shelf LLMs have heterogeneous expertise in a wide range of domains and
tasks so that an ensemble of LLMs can achieve consistently better performance.
Existing ensemble methods for LLMs mainly focus on reward model ranking of
outputs, leading to significant computation overhead. To combat this issue, we
revisit the complementary potential of LLMs and further elaborate it by mining
latent expertise with off-the-shelf reward models. We propose Zooter, a
reward-guided routing method distilling rewards on training queries to train a
routing function, which can precisely distribute each query to the LLM with
expertise about it. We also integrate a tag-based label enhancement to mitigate
noise from uncertainty when using rewards as silver supervision. Zooter shows
computation efficiency in inference as it introduces only a minor computation
overhead of a routing function compared with reward model ranking methods. We
evaluate Zooter on a comprehensive benchmark collection with 26 subsets on
different domains and tasks. Zooter outperforms the best single model on
average and ranks first on 44% of tasks, even surpassing multiple reward model
ranking methods
#InsTag: Instruction Tagging for Analyzing Supervised Fine-tuning of Large Language Models
Foundation language models obtain the instruction-following ability through
supervised fine-tuning (SFT). Diversity and complexity are considered critical
factors of a successful SFT dataset, while their definitions remain obscure and
lack quantitative analyses. In this work, we propose InsTag, an open-set
fine-grained tagger, to tag samples within SFT datasets based on semantics and
intentions and define instruction diversity and complexity regarding tags. We
obtain 6.6K tags to describe comprehensive user queries. Then we analyze
popular open-sourced SFT datasets and find that the model ability grows with
more diverse and complex data. Based on this observation, we propose a data
selector based on InsTag to select 6K diverse and complex samples from
open-source datasets and fine-tune models on InsTag-selected data. The
resulting models, TagLM, outperform open-source models based on considerably
larger SFT data evaluated by MT-Bench, echoing the importance of query
diversity and complexity. We open-source InsTag in
https://github.com/OFA-Sys/InsTag
Panax notoginseng
To investigate the therapeutic effects of PN on intestinal inflammation and microvascular injury and its mechanisms, dextran sodium sulfate- (DSS-) or iodoacetamide- (IA-) induced rat colitis models were used. After colitis model was established, PN was orally administered for 7 days at daily dosage of 1.0 g/kg. Obvious colonic inflammation and mucosal injuries and microvessels were observed in DSS- and IA-induced colitis groups. DAI scores, serum concentrations of VEGFA121, VEGFA165, VEGFA165/VEGFA121, IL-6, and TNF-α, and expression of Rap1GAP and TSP1 proteins in the colon were significantly higher while serum concentrations of IL-4 and IL-10 and MVD in colon were significantly lower in the colitis model groups than in the normal control group. PN promoted repair of colonic mucosal injury and microvessels, attenuated inflammation, and decreased DAI scores in rats with colitis. PN also decreased the serum concentrations of VEGFA121, VEGFA165, VEGFA165/VEGFA121, IL-6, and TNF-α and increased the serum concentrations of IL-4 and IL-10, with the expression of Rap1GAP and TSP1 proteins in colonic mucosa being downregulated. The constituents of PN were identified with HPLC-DAD. To sum up, PN could promote repair of injuries of colonic mucosa and microvessels via downregulating VEGFA isoforms and inhibiting Rap1GAP/TSP1 signaling pathway
Autonomous Navigation and Configuration of Integrated Access Backhauling for UAV Base Station Using Reinforcement Learning
Fast and reliable connectivity is essential to enhancing situational
awareness and operational efficiency for public safety mission-critical (MC)
users. In emergency or disaster circumstances, where existing cellular network
coverage and capacity may not be available to meet MC communication demands,
deployable-network-based solutions such as cells-on-wheels/wings can be
utilized swiftly to ensure reliable connection for MC users. In this paper, we
consider a scenario where a macro base station (BS) is destroyed due to a
natural disaster and an unmanned aerial vehicle carrying BS (UAV-BS) is set up
to provide temporary coverage for users in the disaster area. The UAV-BS is
integrated into the mobile network using the 5G integrated access and backhaul
(IAB) technology. We propose a framework and signalling procedure for applying
machine learning to this use case. A deep reinforcement learning algorithm is
designed to jointly optimize the access and backhaul antenna tilt as well as
the three-dimensional location of the UAV-BS in order to best serve the
on-ground MC users while maintaining a good backhaul connection. Our result
shows that the proposed algorithm can autonomously navigate and configure the
UAV-BS to improve the throughput and reduce the drop rate of MC users.Comment: This work has been submitted to the IEEE for possible publication.
Copyright may be transferred without notice, after which this version may no
longer be accessibl
Characterization of subcellular localization of duck enteritis virus UL51 protein
<p>Abstract</p> <p>Background</p> <p>Knowledge of the subcellular localization of a protein can provide useful insights about its function. While the subcellular localization of many alphaherpesvirus UL51 proteins has been well characterized, little is known about where duck enteritis virus (DEV) UL51 protein (pUL51) is targeted to. Thus, in this study, we investigated the subcellular localization and distribution of DEV pUL51 by computer aided analysis, as well as indirect immunofluorescence (IIF) and transmission immunoelectron microscopy (TIEM) approaches in DEV-infected cells.</p> <p>Results</p> <p>The DEV UL51 gene product was identified as an approximate 34 kDa protein in DEV-infected cells analyzed by western blotting. Computer aided analysis suggested that DEV pUL51 is not targeted to the mitochondrial, extra-cellular or nucleus, but be targeted to the cytoplasmic in host cells, more specifically, palmitoylation of the pUL51 through the N-terminal cysteine at position 9 makes membrane association and Golgi localization possible. Using IIF analysis, we found that DEV pUL51 was first detected in a juxtanuclear region of DEV-infected cells at 9 h postinfection (p.i.), and then was detected widely distributed in the cytoplasm and especially was stronger in the juxtanuclear region from 12 to 60 h p.i. TIEM analysis revealed that DEV pUL51 was mainly associated with cytoplasmic virions and also with some membranous structure near the pUL51-specific immuno-labeling intracellular virion in the cytoplasmic vesicles; moreover, the pUL51 efficiently accumulated in the Golgi apparatus at first, and then was sent to the plasma membrane from the Golgi by some unknown mechanism.</p> <p>Conclusion</p> <p>In this work, we described the basic characteristics of pUL51 subcellular localization and distribution for the first time. From these results, we concluded that palmitoylation at the N-terminal cysteine, which is conserved in all alphaherpesvirus UL51 homologs, is required for its membrane association and Golgi localization, and the pUL51 mainly localized to the juxtanuclear region of DEV-infected cells, as well seemed to be incorporated into mature virions as a component of the tegument. The research will provide useful clues for DEV pUL51 functional analysis, and will be usefull for further understanding the localization properties of alphaherpesvirus UL51 homologs.</p
- …