51 research outputs found
Activity and Durability of Ternary PtRuIr/C for Methanol Electro-oxidation
Carbon supported Pt(1)Ru(1)Ir(x) (0 <= x <= 2) nanoparticles were prepared by it compare nation reductive pyrolysis method and their electrocatalytic activity toward methanol electro-oxidation at 25, 40, and 60 degrees C was investigated. The mass activity (current normalized by the mass of Pt) for methanol electro-oxidation increased as it function of Ir coefficient and cell temperature. Despite the increase in methanol electro-oxidation activity, the addition of Ir does not affect the CO tolerance of the ternary electrocatalyst. The addition of Ir also enhances the durability of the catalyst. The enhancement in activity and durability is discussion based on CO stripping measurements and X-ray photoelectron spectroscopy analysis of the catalysts. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3060111] All rights reserved.ArticleJOURNAL OF THE ELECTROCHEMICAL SOCIETY. 156(3):B397-B402 (2009)journal articl
Orthogonal Temporal Interpolation for Zero-Shot Video Recognition
Zero-shot video recognition (ZSVR) is a task that aims to recognize video
categories that have not been seen during the model training process. Recently,
vision-language models (VLMs) pre-trained on large-scale image-text pairs have
demonstrated impressive transferability for ZSVR. To make VLMs applicable to
the video domain, existing methods often use an additional temporal learning
module after the image-level encoder to learn the temporal relationships among
video frames. Unfortunately, for video from unseen categories, we observe an
abnormal phenomenon where the model that uses spatial-temporal feature performs
much worse than the model that removes temporal learning module and uses only
spatial feature. We conjecture that improper temporal modeling on video
disrupts the spatial feature of the video. To verify our hypothesis, we propose
Feature Factorization to retain the orthogonal temporal feature of the video
and use interpolation to construct refined spatial-temporal feature. The model
using appropriately refined spatial-temporal feature performs better than the
one using only spatial feature, which verifies the effectiveness of the
orthogonal temporal feature for the ZSVR task. Therefore, an Orthogonal
Temporal Interpolation module is designed to learn a better refined
spatial-temporal video feature during training. Additionally, a Matching Loss
is introduced to improve the quality of the orthogonal temporal feature. We
propose a model called OTI for ZSVR by employing orthogonal temporal
interpolation and the matching loss based on VLMs. The ZSVR accuracies on
popular video datasets (i.e., Kinetics-600, UCF101 and HMDB51) show that OTI
outperforms the previous state-of-the-art method by a clear margin
Study on brain damage patterns of COVID-19 patients based on EEG signals
ObjectiveThe coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by the SARA-CoV-2, characterized by high infectivity and incidence. Clinical data indicates that COVID-19 significantly damages patients’ perception, motor function, and cognitive function. However, the electrophysiological mechanism by which the disease affects the patient’s nervous system is not yet clear. Our aim is to investigate the abnormal levels of brain activity and changes in brain functional connectivity network in patients with COVID-19.MethodsWe compared and analyzed electroencephalography signal sample entropy, energy spectrum, and brain network characteristic parameters in the delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (13–30 Hz) bands of 15 patients with COVID-19 and 15 healthy controls at rest.ResultsAt rest, energy values of the four frequency bands in the frontal and temporal lobes of COVID-19 patients were significantly reduced. At the same time, the sample entropy value of the delta band in COVID-19 patients was significantly increased, while the value of the beta band was significantly decreased. However, the average value of the directed transfer function of patients did not show any abnormalities under the four frequency bands. Furthermore, node degree in the temporal lobe of patients was significantly increased, while the input degree of the frontal and temporal lobes was significantly decreased, and the output degree of the frontal and occipital lobes was significantly increased.ConclusionThe level of brain activity in COVID-19 patients at rest is reduced, and the brain functional network undergoes a rearrangement. These results preliminarily demonstrate that COVID-19 patients exhibit certain brain abnormalities during rest, it is feasible to explore the neurophysiological mechanism of COVID-19’s impact on the nervous system by using EEG signals, which can provide a certain technical basis for the subsequent diagnosis and evaluation of COVID-19 using artificial intelligence and the prevention of brain nervous system diseases after COVID-19 infection
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Distribution of Zooplankton Functional Groups in the Chaohu Lake Basin, China
To analyze the structural characteristics of zooplankton functional groups (ZFGs) and their correlation with environmental physicochemical factors in the Chaohu Lake Basin, water samples were collected from October 2019 to July 2020, and the zooplankton species and ZFGs were investigated. A total of 250 species, including 88 protozoa, 115 rotifers, 28 cladocerans, and 19 copepod species, were detected and divided into 16 ZFGs. The ZFGs exhibited obvious spatiotemporal heterogeneity. ZFGs in the Chaohu Lake were notably different from those in rivers and were different between the rivers. In the ecosystem, network analysis showed that protozoan algae/protozoan bacteria (PA/PB), rotifer particle filter (RF), and rotifer small predator (RSG) were important in the spring, summer, and autumn that and small zooplankton filter (SCF) was important in spring, autumn, and winter, while the importance of other ZFGs changed with seasons. Redundancy analysis showed that the environmental factors with a strong correlation between the ZFG compositions differed in each season. Different ZFGs exhibited different correlations with environmental factors. This study showed that ZFGs were closely related to environmental factors and that functional traits can reflect responses to changes in the water environment
Distribution of Zooplankton Functional Groups in the Chaohu Lake Basin, China
To analyze the structural characteristics of zooplankton functional groups (ZFGs) and their correlation with environmental physicochemical factors in the Chaohu Lake Basin, water samples were collected from October 2019 to July 2020, and the zooplankton species and ZFGs were investigated. A total of 250 species, including 88 protozoa, 115 rotifers, 28 cladocerans, and 19 copepod species, were detected and divided into 16 ZFGs. The ZFGs exhibited obvious spatiotemporal heterogeneity. ZFGs in the Chaohu Lake were notably different from those in rivers and were different between the rivers. In the ecosystem, network analysis showed that protozoan algae/protozoan bacteria (PA/PB), rotifer particle filter (RF), and rotifer small predator (RSG) were important in the spring, summer, and autumn that and small zooplankton filter (SCF) was important in spring, autumn, and winter, while the importance of other ZFGs changed with seasons. Redundancy analysis showed that the environmental factors with a strong correlation between the ZFG compositions differed in each season. Different ZFGs exhibited different correlations with environmental factors. This study showed that ZFGs were closely related to environmental factors and that functional traits can reflect responses to changes in the water environment
Nutrition Education for University of British Columbia Students : Opportunities, Facilitators & Barriers
Currently, the University of British Columbia (UBC) Wellness Centre’s nutrition resources are not being used by UBC students as much as desired (Stevens, H., Personal Communication, January 21, 2019). Our community partner, the UBC Wellness Centre, would like to find new ways to offer nutrition resources that will fit the needs and wants of students, with the hope of encouraging more students to use these resources. The main goal of this project is to provide the UBC Wellness Centre with information about how nutrition-related resources can capture the interest of UBC students.
In collaboration with the UBC Wellness Centre and SEEDS Sustainability Program, our team developed a survey using the Qualtrics Survey software and distributed it through our individual social media accounts, posters, class announcements, and in-person with an iPad. The results of our study showed that most students prefer to learn about practical cooking skills and also prefer their resources to be easily accessible and readily available. Among other formats, websites and workshops were mentioned as the preferred style of learning. Although this sample size was not representative of the whole UBC student population, the information from these responses can provide the UBC Wellness Centre with an idea of what some students are interested in.
Our team was successful in meeting most of our short-term objectives, which included completing a Qualtrics survey by mid-February and providing a summary of our relevant data to the UBC Wellness Centre. The one short-term objective that we did not meet was to collect 200 survey responses, since we were only able to collect a total of 160 responses within our time limit. The success of this project will continue to be evaluated by measuring changes in attendance at nutrition workshops and the utilization rate of nutritional resources in the future. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”Land and Food Systems, Faculty ofUnreviewedUndergraduat
Signature miRNAs Involved in the Innate Immunity of Invertebrates
<div><p>The innate immune system, including the cell-based immunity (mainly apoptosis and phagocytosis) and the humoral immunity (such as pro-phenoloxidase system), is the first defense line of animals against the infection of pathogens in a non-specific manner, which is fine regulated through the gene expression regulations. The microRNAs (miRNAs) are recognized as important regulators of gene expression. To date, however, a comprehensive view about the regulation of innate immunity by miRNAs is not available. To address this issue, the signature miRNAs involved in the innate immunity were characterized in this study. The phagocytosis, apoptosis and phenoloxidase (PO), a key enzyme in the pro-phenoloxidase system, of invertebrate shrimp were activated or inhibited, followed by the small RNA sequencing. The results showed that a total of 24 miRNAs took great effects on phagocytosis, apoptosis or the pro-phenoloxidase system, which were further confirmed by Northern blots. Among the 24 innate immunity-associated miRNAs, 21 miRNAs were conserved in animals, suggesting that these miRNAs might share the similar or the same functions in different species of animals. Based on degradome sequencing and prediction of target genes, it was found that the miRNAs might mediate the regulations of phagocytosis, apoptosis or pro-phenoloxidase system by targeting different genes. Therefore our study presented the first comprehensive view of the miRNAs associated with innate immunity, which would facilitate to reveal the molecular events in the regulation of innate immunity.</p> </div
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