short time window
Recently Published Documents


TOTAL DOCUMENTS

65
(FIVE YEARS 33)

H-INDEX

11
(FIVE YEARS 1)

2021 ◽  
Author(s):  
Dehao Huang ◽  
Jianhuan Li ◽  
Fangxiao Hu ◽  
Qitong Weng ◽  
Tongjie Wang ◽  
...  

ABSTRACTHuman pluripotent stem cell (hPSC)-induced NK (iNK) cells are a promising “off-the-shelf” cell product for universal immune therapy. Conventional methods for iNK cell regeneration from hPSCs include embryonic body-formation and feeder-based expansion steps, which bring instability, time-consuming, and high costs for manufacture. In this study, we develop an embryonic body-free, organoid aggregate method for NK cell regeneration from hPSCs. In a short time window of 27-day induction, millions of hPSC input can produce over billions of iNK cells without the necessity of NK cell-expansion feeders. The iNK cells highly express classical toxic granule proteins, apoptosis-inducing ligands, as well as abundant activating and inhibitory receptors. Functionally, the iNK cells eradicate human tumor cells by mechanisms of direct cytotoxity, apoptosis, and antibody-dependent cellular cytotoxicity. This study provides a reliable scale-up method for regenerating human NK cells from hPSCs, which promotes the universal availability of NK cell products for immune therapy.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Amir Mohammadzade Lajevardi ◽  
Morteza Amini

AbstractTargeted cyber attacks, which today are known as Advanced Persistent Threats (APTs), use low and slow patterns to bypass intrusion detection and alert correlation systems. Since most of the attack detection approaches use a short time-window, the slow APTs abuse this weakness to escape from the detection systems. In these situations, the intruders increase the time of attacks and move as slowly as possible by some tricks such as using sleeper and wake up functions and make detection difficult for such detection systems. In addition, low APTs use trusted subjects or agents to conceal any footprint and abnormalities in the victim system by some tricks such as code injection and stealing digital certificates. In this paper, a new solution is proposed for detecting both low and slow APTs. The proposed approach uses low-level interception, knowledge-based system, system ontology, and semantic correlation to detect low-level attacks. Since using semantic-based correlation is not applicable for detecting slow attacks due to its significant processing overhead, we propose a scalable knowledge-based system that uses three different concepts and approaches to reduce the time complexity including (1) flexible sliding window called Vermiform window to analyze and correlate system events instead of using fixed-size time-window, (2) effective inference using a scalable inference engine called SANSA, and (3) data reduction by ontology-based data abstraction. We can detect the slow APTs whose attack duration is about several months. Evaluation of the proposed approach on a dataset containing many APT scenarios shows 84.21% of sensitivity and 82.16% of specificity.


2021 ◽  
Author(s):  
Longfei Ma ◽  
Dan Xie ◽  
Xiwen Lin ◽  
Hengyu Nie ◽  
Jian Chen ◽  
...  

The chromatin state undergoes global and dynamic changes during spermatogenesis, and is critical to chromosomal synapsis, meiotic recombination, and transcriptional regulation. However, the key regulators involved and the underlying molecular mechanisms remain poorly understood. Herein we report that mouse BEND2, one of the BEN-domain- containing proteins conserved in vertebrates, was specifically expressed in spermatogenic cells within a short time-window spanning meiotic initiation, and that it plays an essential role in the progression of prophase in meiosis I. Bend2 gene knockout in male mice arrested meiosis at the transition from zygonema to pachynema, disrupted synapsis and DNA double-strand break repair, and induced non-homologous chromosomal pairing. BEND2 interacted with a number of chromatin-associated proteins including ZMYM2, LSD1, CHD4, and ADNP,which are components of certain transcription-repressor complexes. BEND2-binding sites were identified in diverse chromatin states and enriched in simple sequence repeats. BEND2 contributed to shutting down the mitotic gene-expression program and to the activation of meiotic and post-meiotic gene expression, and it regulated chromatin accessibility as well as the modification of H3K4me3. Therefore, our study identified BEND2 as a novel and key regulator of meiosis, gene expression, and chromatin state during mouse spermatogenesis.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S293-S293
Author(s):  
Jonathan Altamirano ◽  
Grace Tam ◽  
Marcela Lopez ◽  
India Robinson ◽  
Leanne Chun ◽  
...  

Abstract Background While pediatric cases of COVID-19 are at low risk for adverse events, schoolchildren should be considered for surveillance as they can become infected at school and serve as sources of household or community transmission. Our team assessed the feasibility of young children self-collecting SARS-CoV-2 samples for surveillance testing in an educational setting. Methods Students at a K-8 school were tested weekly for SARS-CoV-2 from September 2020 - June 2021. Error rates were collected from September 2020 - January 2021. Clinical staff provided all students with instructions for anterior nares specimen self-collection and then observed them to ensure proper technique. Instructions included holding the sterile swab while making sure not to touch the tip, inserting the swab into their nostril until they start to feel resistance, and rubbing the swab in four circles before repeating the process in their other nostril. An independent observer timed random sample self-collections from April - June 2021. Results 2,590 samples were collected from 209 students during the study period when data on error rates were collected. Errors occurred in 3.3% of all student encounters (n=87). Error rates over time are shown in Figure 1, with the highest rate occurring on the first day of testing (n=20/197, 10.2%) and the lowest in January 2021 (n=1/202, 0.5%). 2,574 visits for sample self-collection occurred during the study period when independent timing data was collected (April - June 2021). Of those visits, 7.5% (n=193) were timed. The average duration of each visit was 70 seconds. Figure 1. Swab Error Rates Over Time Conclusion Pediatric self-collected lower nasal swabs are a viable and easily tolerated specimen collection method for SARS-CoV-2 surveillance in school settings, as evidenced by the low error rate and short time window of sample self-collection during testing. School administrators should expect errors to drop quickly after implementing testing. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yu Xu ◽  
Qi Li ◽  
Zhenzhou Tang

Breathing and heartbeat are critical vital signs which reflect the health status of human beings. Aiming to accurately measure the vital sign in short time window, a novel signal processing method for Doppler radar vital sign detection is proposed. Firstly, a two-step I/Q mismatch correction method which, respectively, estimates the time invariant phase imbalance and gain ratio of I/Q channels in the calibration step and the direct-current offsets during normal operation has been proposed. By decreasing the number of estimation parameters from 5 to 2, the parameters can be effectively estimated with data distributed over shorter arc lengths. Then, to solve the discontinuity occurred in arctangent demodulation, the displacement information of chest movement is extracted from the calibrated I/Q signals by extended differentiate and cross multiply algorithm. Finally, instead of Fourier transform-based methods which require long time windows to guarantee sufficient frequency resolution, the optimal parameters of respiration and heartbeat are found by the intelligent search of the differential evolution algorithm. The experimental results show that the proposed method can accurately measure respiratory rate and heartbeat rate with a short time window. For the 8 s time window, the mean absolute errors of respiration and heartbeat were 0.52 bpm and 0.79 bpm, respectively, demonstrating its promise in real-time applications.


Author(s):  
Virginia Smith ◽  
Patrick Heelan ◽  
Emily Essex ◽  
Suzanne Weaver Smith

The Kentucky Eclipse Ballooning Project began in early 2015 when students and faculty from The University of Kentucky attended the NASA Marshall Space Flight Center BalloonSat Workshop in Huntsville, Alabama. The students accelerated their preparations after the Eclipse Ballooning Project Workshop hosted in Bozeman, Montana where they built and learned systems designed by Montana Space Grant. In 2016, the students began a sequence of 10 balloon launches in preparation for the total solar eclipse on August 21, 2017. In the early stages of this project, University of Kentucky students set the goal to capture footage of a separate high-altitude weather balloon in front of the solar eclipse, an image dubbed “The Kentucky Money Shot.” After establishing that goal, students began working on approaches and designs to capture this picture with one overarching theme: redundancy. Every aspect of the project from the number of balloons and imaging systems to tracking systems and launch procedures were designed with redundant aspects and through collaboration among the payload, ground station, launch, and mission control teams. The short time window of eclipse totality, 2 minutes 28 seconds, motivated design iterations throughout the progressive practice launches and ground tests including launching two balloons simultaneously, streaming and storing footage of the flight from multiple cameras, and using SPOT Trackers and Iridium systems as multiple tracking approaches. All of these practices and tests led to flying the final redundant designs on August 21st, 2017 to successfully capture “The Kentucky Money Shot”.


2021 ◽  
Author(s):  
Jibeom Choi ◽  
Woojoo Kim ◽  
Woncheol Song ◽  
Sang-im Lee ◽  
Piotr G Jablonski

Accurate measurements of travel distance and speed are crucial for the analysis of animal movements. Measuring the movements of ants entails measuring the change in locations registered at time intervals. This process involves the dilemma of setting the proper time window: a short time window is vulnerable to spatial errors in observation, while a long time window leads to underestimation of the travel distance. To overcome these difficulties, we propose a novel algorithm that successively interpolates two consecutive points of ant's trajectory for a given time window by embracing the alternating tripod gait of ants. We demonstrate that this algorithm is more reliable compared to the conventional method of travel distance estimation based on the sum of the consecutive straight-line displacements (SLD). After obtaining speed estimates for a range of sampling time windows, we applied a fitting method that can estimate the actual speed without prior knowledge of spatial error distribution. We compared results from several methods of speed and curvature extracted from the empirical data of ant trajectories. We encourage empirical scientists to utilize the proposed methods rather than the conventional SLD method of speed estimation as this process is a more reliable and subjective selection of the sampling time window can be avoided.


2021 ◽  
Vol 9 ◽  
Author(s):  
Theunis Piersma ◽  
Robert E. Gill ◽  
Daniel R. Ruthrauff

In a 1998 paper entitled “Guts don’t fly: small digestive organs in obese bar-tailed godwits,” Piersma and Gill (1998) showed that the digestive organs were tiny and the fat loads huge in individuals suspected of embarking on a non-stop flight from Alaska to New Zealand. It was suggested that prior to migratory departure, these godwits would shrink the digestive organs used during fuel deposition and boost the size and capacity of exercise organs to optimize flight performance. Here we document the verity of the proposed physiomorphic changes by comparing organ sizes and body composition of bar-tailed godwits Limosa lapponica baueri collected in modesty midway during their fueling period (mid-September; fueling, n = 7) with the previously published data for godwits that had just departed on their trans-Pacific flight (October 19; flying, n = 9). Mean total body masses for the two groups were nearly identical, but nearly half of the body mass of fueling godwits consisted of water, while fat constituted over half of total body mass of flying godwits. The two groups also differed in their fat-free mass components. The heart and flight muscles were heavier in fueling godwits, but these body components constituted a relatively greater fraction of the fat-free mass in flying godwits. In contrast, organs related to digestion and homeostasis were heavier in fueling godwits, and most of these organ groups were also relatively larger in fueling godwits compared to flying godwits. These results reflect the functional importance of organ and muscle groups related to energy acquisition in fueling godwits and the consequences of flight-related exertion in flying godwits. The extreme physiomorphic changes apparently occurred over a short time window (≤1 month). We conclude that the inferences made on the basis of the 1998 paper were correct. The cues and stimuli which moderate these changes remain to be studied.


2021 ◽  
Vol 12 ◽  
Author(s):  
Baofu Wang ◽  
Yang Li ◽  
Xuezeng Hao ◽  
Jingjing Yang ◽  
Xiaowan Han ◽  
...  

Background/Aims: This study aimed to compare the clinical value of the peak time point and area under the curve (AUC) of miRNAs and conventional biomarkers in acute myocardial infarction (AMI).Methods: A literature search was carried out in PubMed, Web of Science, Embase, and Cochrane systematically. Screening studies, extracting data, and assessing article quality were performed independently by two researchers. Also, the names of miRNAs in the included studies were standardized by the miRBase database.Results: A total of 40 studies, encompassing 6,960 participants, were included in this systematic review. The samples of circulating miRNAs were mainly from the plasma. The results of this systematic review displayed that miR-1-3p, miR-19b-3p, miR-22-5p, miR-122-5p, miR-124-3p, miR-133a/b, miR-134-5p, miR-150-5p, miR-186-5p, miR-208a, miR-223-3p, miR-483-5p, and miR-499a-5p reached peak time earlier and showed a shorter time window than the conventional biomarkers despite the different collection times of initial blood samples. miR-1-3p, miR-19b-3p, miR-133a/b, miR-208a/b, miR-223-3p, miR-483-5p, and miR-499a-5p were shown to be more valuable than classical biomarkers for the early diagnosis of AMI, and these miRNAs appeared to have the most potential biomarkers within 4 h of the onset of symptoms except miR-133a/b and miR-208b. Moreover, combined miRNAs or miRNAs combined with classical biomarkers could compensate for the deficiency of single miRNA and conventional biomarker in sensitivity or specificity for an optimal clinical value.Conclusions: miR-1-3p, miR-19b-3p, miR-208a, miR-223-3p, miR-483-5p, and miR-499a-5p are promising biomarkers for AMI due to their satisfactory diagnostic accuracy and short time window (within 4 h of the onset of symptoms).


2021 ◽  
pp. 0271678X2110183
Author(s):  
Nikolaj Bøgh ◽  
Rie B Olin ◽  
Esben SS Hansen ◽  
Jeremy W Gordon ◽  
Sabrina K Bech ◽  
...  

Acute ischemic stroke patients benefit from reperfusion in a short time-window after debut. Later treatment may be indicated if viable brain tissue is demonstrated and this outweighs the inherent risks of late reperfusion. Magnetic resonance imaging (MRI) with hyperpolarized [1-13C]pyruvate is an emerging technology that directly images metabolism. Here, we investigated its potential to detect viable tissue in ischemic stroke. Stroke was induced in pigs by intracerebral injection of endothelin 1. During ischemia, the rate constant of pyruvate-to-lactate conversion, kPL, was 52% larger in penumbra and 85% larger in the infarct compared to the contralateral hemisphere (P = 0.0001). Within the penumbra, the kPL was 50% higher in the regions that later infarcted compared to non-progressing regions (P = 0.026). After reperfusion, measures of pyruvate-to-lactate conversion were slightly decreased in the infarct compared to contralateral. In addition to metabolic imaging, we used hyperpolarized pyruvate for perfusion-weighted imaging. This was consistent with conventional imaging for assessment of infarct size and blood flow. Lastly, we confirmed the translatability of simultaneous assessment of metabolism and perfusion with hyperpolarized MRI in healthy volunteers. In conclusion, hyperpolarized [1-13C]pyruvate may aid penumbral characterization and increase access to reperfusion therapy for late presenting patients.


Sign in / Sign up

Export Citation Format

Share Document