Visual Anomaly Detection in Event Sequence Data

Anomaly detection is a common analytical task that aims to identify rare cases that differ from the typical cases that make up the majority of a dataset. When applied to the analysis of event sequence data, the task of anomaly detection can be complex because the sequential and temporal nature of such data results in diverse definitions and flexible forms of anomalies. This, in turn, increases the difficulty in interpreting detected anomalies. In this paper, we propose an unsupervised anomaly detection algorithm based on Variational AutoEncoders (VAE) to estimate underlying normal progressions for each given sequence represented as occurrence probabilities of events along the sequence progression. Events in violation of their occurrence probability are identified as abnormal. We also introduce a visualization system, EventThread3, to support interactive exploration and interpretations of anomalies within the context of normal sequence progressions in the dataset through comprehensive one-to-many sequence comparison. Finally, we quantitatively evaluate the performance of our anomaly detection algorithm and demonstrate the effectiveness of our system through a case study

Anomaly detection in spatiotemporal data via regularized non-negative tensor analysis

Anomaly detection in multidimensional data is a challenging task. Detecting anomalous mobility patterns in a city needs to take spatial, temporal, and traffic information into consideration. Although existing techniques are able to extract spatiotemporal features for anomaly analysis, few systematic analysis about how different factors contribute to or affect the anomalous patterns has been proposed. In this paper, we propose a novel technique to localize spatiotemporal anomalous events based on tensor decomposition. The proposed method employs a spatial-feature-temporal tensor model and analyzes latent mobility patterns through unsupervised learning. We first train the model based on historical data and then use the model to capture the anomalies, i.e., the mobility patterns that are significantly different from the normal patterns. The proposed technique is evaluated based on the yellow-cab dataset collected from New York City. The results show several interesting latent mobility patterns and traffic anomalies that can be deemed as anomalous events in the city, suggesting the effectiveness of the proposed anomaly detection method

The various substrates of Usnea aurantiaco-atra and its algal sources in the Fildes Peninsula, Antarctica

The lichen species Usnea aurantiaco-atra (Jacq.) Bory is the most dominant vegetation on the Fildes Peninsula, Antarctica. Most individuals grow on rocks, and some are found with mosses. During the 27th and 28th Chinese National Antarctic Research expeditions of the Great Wall Station, U. aurantiaco-atra was observed growing on the lichen thallus of Umbilicaria antarctica Frey & I.M. Lamb, or on wood, which indicated that Usnea aurantiaco-atra could grow on various substrates. The diversities of the symbionts in U. aurantiaco-atra collected in the Fildes Peninsula were investigated using ITS rDNA sequences. The results showed that the sequences from mycobionts of U. aurantiaco-atra growing on various substrates did not exhibit significant differences. All photobionts in this lichen species were the green algae Trebouxia jamesii (Hildreth & Ahmadjian) Gärtner. The identical sequences from the photobionts of both Umbilicaria antarctica and Usnea aurantiaco-atra indicated there was an algae pool in this area and different mycobionts could obtain their algal partners from this pool. The variety of substrates for U. aurantiaco-atra suggested its photobiont could be obtained from a mature lichen thallus by vegetative propagation; from other lichen thalli (e.g. Umbilicaria antarctica); or from the surroundings. This study will promote understanding of the distribution of photobionts and the process of lichenization

A network for long-term monitoring of vegetation in the area of Fildes Peninsula, King George Island

Climate warming has become evident in the maritime Antarctic over the past decades, and has already influenced the growing season and the population size of two native vascular plants in Antarctica, Deschampsia antarctica and Colobanthus quitensis. Both vascular plant species are therefore regarded as good bioindicators of regional warming in west Antarctica. To carry out long-term monitoring of vegetation (mainly using D. antarctica) and build a comprehensive research platform for multi-disciplinary study (including botany, microbiology, ecology, and environmental science) for Chinese scientists, 13 permanent plots were established in January and February of 2013–2015 in the area of Fildes Peninsula (King George Island). Here we present the benchmark data of the first observations from these plots, including site characteristics, and the population and associates of D. antarctica in each plot. The basic data are important to understand the vegetation change, distribution range, and expansion of D. antarctica in Antarctica under future climate change scenarios

Evaluation of the efficacy and safety of intravenous remdesivir in adult patients with severe COVID-19: study protocol for a phase 3 randomized, double-blind, placebo-controlled, multicentre trial.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by a novel corinavirus (later named SARS-CoV-2 virus), was fistly reported in Wuhan, Hubei Province, China towards the end of 2019. Large-scale spread within China and internationally led the World Health Organization to declare a Public Health Emergency of International Concern on 30th January 2020. The clinical manifestations of COVID-19 virus infection include asymptomatic infection, mild upper respiratory symptoms, severe viral pneumonia with respiratory failure, and even death. There are no antivirals of proven clinical efficacy in coronavirus infections. Remdesivir (GS-5734), a nucleoside analogue, has inhibitory effects on animal and human highly pathogenic coronaviruses, including MERS-CoV and SARS-CoV, in in vitro and in vivo experiments. It is also inhibitory against the COVID-19 virus in vitro. The aim of this study is to assess the efficacy and safety of remdesivir in adult patients with severe COVID-19. METHODS: The protocol is prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. This is a phase 3, randomized, double-blind, placebo-controlled, multicentre trial. Adults (≥ 18 years) with laboratory-confirmed COVID-19 virus infection, severe pneumonia signs or symptoms, and radiologically confirmed severe pneumonia are randomly assigned in a 2:1 ratio to intravenously administered remdesivir or placebo for 10 days. The primary endpoint is time to clinical improvement (censored at day 28), defined as the time (in days) from randomization of study treatment (remdesivir or placebo) until a decline of two categories on a six-category ordinal scale of clinical status (1 = discharged; 6 = death) or live discharge from hospital. One interim analysis for efficacy and futility will be conducted once half of the total number of events required has been observed. DISCUSSION: This is the first randomized, placebo-controlled trial in COVID-19. Enrolment began in sites in Wuhan, Hubei Province, China on 6th February 2020. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04257656. Registered on 6 February 2020

Paleomagnetic study of Permian and Triassic basalts from the Baoshan block in western Yunnan, SW China

The Baoshan Block is a wedge-shaped fragment that forms the northern tip of the Sibumasu Terrane in westernmost Yunnan Province, SW China. The fragment detached from Gondwana in the Early Permian before amalgamating with eastern Eurasia in the Late Triassic. It is now bounded by the Gaoligong Suture Zone to its west and the Chongshan Suture Zone to the east. The initial objective of this study was to use paleomagnetic data from two volcanic units to reconstruct the Baoshan Block’s rotation and translation history over this interval. However, based on the paleomagnetic analyses, the magnetizations of both the Lower Permian and the Upper Triassic basalts record secondary overprints. The age of remagnetization likely coincides with the regional crustal shortening caused by the India-Eurasia convergence at 30 Ma. The 10% untilting of the mean directions from twenty-nine sites yields a declination of 4.0°, inclination of 64.4°, where α_95= 5.9°, and k = 15.4. This gives a paleo-latitude of 46.5 ±2.9°N at that time. The result supports the “tectonic extrusion” model with ~2928 ± 534 km of southward translation of the Baoshan Block, induced by the India-Eurasia convergence. Aside from the tectonic modeling, the project’s other objective was to evaluate the efficacy of using one block-sampling per cooling site in paleomagnetic studies.published_or_final_versionEarth SciencesMasterMaster of Philosoph

Paleomagnetic study of Permian and Triassic basalts from the Baoshan block in western Yunnan, SW China

abstractEarth SciencesMasterMaster of Philosoph

Distribution and environmental correlations of picoeukaryotes in an Arctic fjord (Kongsfjorden, Svalbard) during the summer

Picoeukaryotes are numerous in the summer in the High-Arctic fjord Kongsfjorden, in western Spitsbergen, Svalbard. However, little research has been conducted on the community structure and diversity of picoeukaryotes. We conducted a detailed investigation of the distribution and environmental correlations of picoeukaryotes in Kongsfjorden in July 2012, using 454-pyrosequencing of 18S rDNA and redundant analysis. Eight classes were classified with proportions larger than 1%. These were Mamiellophyceae, Chrysophyceae, Spirotrichea, Telonemea, Cryptophyceae, Bolidophyceae, Picomonadea and Dictyochophyceae. Five genera were classified, with Micromonas (55.6%) and Bathycoccus (7.8%) as the dominant genera. The diversity and composition of the picoeukaryote community were very distinct in different water masses sampled in the water column (i.e., vertically), but were not distinct from station to station (i.e., horizontally). Biodiversity was greater in the Atlantic waters than in glacial waters. Mamiellophyceae, Bolidophyceae, Picomonadea and Dictyochophyceae had significantly different distributions (p < 0.01) in the three water masses (surface water, intermediate water and transformed Atlantic Water). Nitrogen, salinity and temperature were the first three primary environmental factors shaping the community structure of picoeukaryotes