Characterization of unknown <i>Bacillus subtilis </i>genes with transposon sequencing

The exact essentials for maintaining a living bacterial cell are still unclear. out of over 4000 genes in the model bacteria Bacillus subtilis and Escherichia coli, only approximately 260 genes have been identified as essential. However, this number does not accurately reflect the bacterial requirements due to the presence of many redundant pathways. To overcome this problem, we utilizes a genome-reduced strain of B. subtilis, PG10, that lacks 35% of the original chromosome, and likely many redundant pathways. Through extensive Tn-seq analysis, described in Chapter 2, we revealed 133 new essential genes in PG10, 69 of which remain functionally uncharacterized. In this thesis we describe the functional characterization of the unknown genes ytiB, ywnA, and ywgA. Chapter 3 reveals that the absence of ytiB leads to the overexpression of mtlR and subsequent upregulation of the mtlA operon involved in mannitol utilization. In Chapter 4, we explore the role of YwnA in oxidative stress response, and its regulatory impact on the ywnAB operon. Chapter 5 describes the discovery of a new dNTP triphosphatase that is controlled by YwgA. Finally, Chapter 6 investigates a phenomenon that we encountered throughout our research; a possible confounding effect on the transcriptome due to presence of the erythromycin resistance marker ermC. In conclusion, this PhD thesis elucidates the activity of several unknown genes in B. subtilis, thereby further our understanding of this important bacterial model system, and provides useful insights in the use of genome reduction to help uncover the minimal necessities for a bacterial cell

Tuning the optoelectronic properties of emerging solar absorbers through cation disorder engineering

Chalcogenide solar absorbers, such as AgBiS2 and kesterites, have gained a resurgence of interest recently, owing to their high stability compared to metal–halide compounds, as well as their rising efficiencies in photovoltaic devices. Although their optical and electronic properties are conventionally tuned through the composition and structure, cation disorder has increased in prominence as another important parameter that influences these properties. In this minireview, we define cation disorder as the occupation of a cation crystallographic site with different species, and the homogeneity of this cation disorder as how regular the alternation of species in this site is. We show that cation disorder is not necessarily detrimental, and can lead to increases in absorption coefficient and reductions in bandgap, enabling the development of ultrathin solar absorbers for lightweight photovoltaics. Focusing on kesterites and ABZ2 materials (where A = monovalent cation, B = divalent cation, and Z is a chalcogenide anion), we discuss how the degree and homogeneity of cation disorder influences the optical properties, charge-carrier transport and photovoltaic performance of these materials, as well as how cation disorder could be tuned and quantified. We finish with our perspectives on the important questions moving forward in making use of cation disorder engineering as a route to achieve more efficient solar absorbers

Rejecting another pains the self: The impact of perceived future rejection

The current investigation examined whether people would experience a higher level of pain after rejecting another person, especially for those high in evaluative concern, through increased perceptions of future rejection. Three experiments provide converging support to these predictions. After reliving a past rejecting experience (Experiments 1 and 2) and concurrently rejecting another person (Experiment 3), the source of rejection experienced a higher level of pain than participants in the control conditions. We also found that evaluative concern, either primed (Experiment 2) or measured (Experiment 3) moderated the above effect, such that this effect was only observed among participants high in evaluative concern, but not among those low in evaluative concern. Moreover, perceived future rejection mediated the moderating effect of evaluative concern and rejecting another person on the levels of pain that people experience (Experiment 3). These findings contribute to the literature by showing a mechanism explaining why rejecting another person pains the self and who are more susceptible to this influence.postprin

Estimation of Time-varying Frequency and its Rate of Change in Low-inertia Power Systems

In this paper, a hierarchical estimation scheme is designed to track the frequency and its rate of change of non-stationary power signals. The frequency is retrieved by a kernel-based parameter estimator in the first step. Subsequently, the frequency estimates are injected into a kernel-based numerical differentiator to extract its changing rate. Thanks to the deployed Volterra integral operator and suitably designed kernel-functions, the proposed estimator can achieve very fast convergence speed without compromising the robustness against noise. Therefore, the real-time estimates are able to follow the time-varying frequency and its rate of change with satisfactory accuracy. The effectiveness and robustness of the proposed method are verified by numerical experiments considering typical practical scenarios under the disturbance of noise. The results of the proposed method are compared with a highly-concerned quadrature phase-locked-loop (QPLL) method

In vivo effects on intron retention and exon skipping by the U2AF large subunit and SF1/BBP in the nematode Caenorhabditis elegans

The in vivo analysis of the roles of splicing factors in regulating alternative splicing in animals remains a challenge. Using a microarray-based screen, we identified a Caenorhabditis elegans gene, tos-1, that exhibited three of the four major types of alternative splicing: intron retention, exon skipping, and, in the presence of U2AF large subunit mutations, the use of alternative 3' splice sites. Mutations in the splicing factors U2AF large subunit and SF1/BBP altered the splicing of tos-1. 3' splice sites of the retained intron or before the skipped exon regulate the splicing pattern of tos-1. Our study provides in vivo evidence that intron retention and exon skipping can be regulated largely by the identities of 3' splice sites

Parent-adolescent attachment and peer attachment associated with Internet Gaming Disorder: a longitudinal study of first-year undergraduate students

Background and aims: Given that Internet Gaming Disorder (IGD) has tentatively been included in DSM-5 as a psychiatric disorder, it is important that the effect of parental and peer attachment in the development of IGD is further explored. Methods: Utilizing a longitudinal design, this study investigated the bidirectional association between perceived Q1 parent-adolescent attachment, peer attachment, and IGD among 1,054 first-year undergraduate students (58.8% female). The students provided demographic information (e.g., age, gender) and were assessed using the nine-item Internet Gaming Disorder Scale and the Inventory of Parent and Peer Attachment. Assessments occurred three times, six months apart (October 2017; April 2018; October 2018). Results: Cross-lagged panel models suggested that IGD weakly predicted subsequent mother attachment but significantly negatively predicted father attachment. However, father and mother attachment could not predict subsequent IGD. Moreover, peer attachment has bidirectional association with IGD. Further, the model also demonstrated stable crosssectional negative correlations between attachment and IGD across all three assessments. Discussion and conclusions: The findings of the present study did not show a bidirectional association between parental attachment and IGD, but they did show a negative bidirectional association between peer attachment and IGD. The results suggested previous cross-sectional associations between IGD and attachment, with larger links among males than females at the first measurement point. We found that peer attachment could negatively predict subsequent IGD, which indicates that peer attachment plays an important role in preventing addictive gaming behaviors for university students

Enhancement of Gear Fault Detection Using Narrowband Interference Cancellation

The development of enhanced fault detection ability for gearbox systems has received considerable attention in recent years. Detecting the gear fault easier is very important for maintenance action. This has driven the need in research for enhanced gear fault detection method. The goal is to extract periodic impulse signal from the very noise signal which mainly contains the narrowband signals. This can be done by enhancing the impulsive signals while suppressing the narrowband signals. This paper used a new method, Narrowband Interference Cancellation, to detect the gear fault. This method reserves the impulsive signal produced by gear fault and removes the other signals out. The methodology is demonstrated on a gearbox run-to-failure test. The results show that Narrowband Interference Cancellation can enable the gear fault detection easier

Online Visualization and Analysis of NASA Satellite-Based Global and Regional Precipitation Products Through Giovanni

Observational data are essential for Earth science research and applications. Traditional ground-based observations suffer from many limitations (e.g. costly deployment). As a result, data are often sparse and inconsistent, especially over vast oceans that cover nearly 71% of the Earth's surface, and for remote continents. Precipitation is one of the important physical parameters in the global hydrological cycle and other disciplines. Each year, severe floods and droughts happen in different parts of the world and cause significant damage to the economy, as well as human casualties (e.g. Hurricane Katrina, the Dust Bowl). Accurate and timely precipitation observations and predictions are important for research and applications. However, ground-based precipitation observations are quite limited, especially in remote and mountainous regions. Since the satellite era began, satellite-based precipitation products have gained popularity in Earth science research, applications, and education. Accessing satellite products can be a daunting task to many users, especially those who do not have prior experience or knowledge with satellite data. Recognizing this obstacle, the NASA Goddard Earth Sciences and Data and Information Services Center (GES DISC), home to data archives for the NASA-JAXA Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM), has developed data services including an online visualization and analysis tool, Giovanni (the Geospatial Interactive Online Visualization ANd aNalysis Infrastructure), enabling users at different levels to access, explore, and evaluate NASA satellite-based data products without downloading either data and software, or requiring coding. Currently, global and regional precipitation products from different satellite missions (TRMM, GPM) and projects (e.g. the Modern Era Retrospective-analysis for Research and Applications Version 2 (MERRA-2), and the North American Land Data Assimilation System (NLDAS)), ranging from half-hourly to monthly temporal resolution, are available in Giovanni. There are over 1900 variables in Giovanni, covering measurements in precipitation, hydrology, atmospheric dynamics, atmospheric chemistry, etc. In this poster presentation, we will provide a live demonstration of Giovanni and its latest development, including precipitation-related variables, and new basic features such as polar projections. The session will also provide a Q&A opportunity for attendees

Surface defect detection of steel based on improved YOLOv7 model

In response to the inevitable surface defects in the manufacturing process of hot-rolled steel, this paper proposes an improved steel surface defect detection model based on YOLOv7. In the Extended Efficient Large Aggregation Network (E-ELAN), the model replaces conventional convolution with Omni-Dimensional Dynamic Convolution (ODConv) to enhance the network’s sensitivity to feature extraction using a combination of various attention mechanisms. Additionally, the detection head in the head section is replaced with an Efficient Decoupled Detection Head, enhancing the model’s capability to classify and locate small defects. The proposed model is tested on the public dataset NEU-DET, achieving a high mAP of 76,5 %. This effectively enhances the model’s ability to detect surface defects in steel while maintaining a fast detection speed

Impact of Fiber Structure on the Material Stability and Rupture Mechanisms of Coronary Atherosclerotic Plaques

The rupture of an atherosclerotic plaque in the coronary circulation remains the main cause of heart attack. As a fiber-oriented structure, the fiber structure, in particular in the fibrous cap (FC), may affect both loading and material strength in the plaque. However, the role of fiber orientation and dispersion in plaque rupture is unclear. Local orientation and dispersion of fibers were calculated for the shoulder regions, mid FC, and regions with intimal thickening (IT) from histological images of 16 human coronary atherosclerotic lesions. Finite element analysis was performed to assess the effect of these properties on mechanical conditions. Fibers in shoulder regions had markedly reduced alignment (Median [interquartile range] 12.9° [6.6, 18.0], $p$ <0.05) compared with those in mid FC (6.1° [5.5, 9.0]) and IT regions (6.7° [5.1, 8.6]). Fiber dispersion was highest in shoulders (0.150 [0.121, 0.192]), intermediate in IT (0.119 [0.103, 0.144]), and lowest in mid FC regions (0.093 [0.081, 0.105], $p$ <0.05). When anisotropic properties were considered, stresses were significantly higher for the mid FC ($p$ = 0.030) and IT regions ($p$ = 0.002) and no difference was found for the shoulder or global regions. Shear (sliding) stress between fibers in each region and their proportion of maximum principal stress were: shoulder (25.8 kPa [17.1, 41.2], 12.4%), mid FC (13.9 kPa [5.8, 29.6], 13.8%), and IT (36.5 kPa [25.9, 47.3], 15.5%). Fiber structure within the FC has a marked effect on principal stresses, resulting in considerable shear stress between fibers. Fiber structure including orientation and dispersion may determine mechanical strength and thus rupture of atherosclerotic plaques. KThis research is supported by HRUK (RG2638/14/ 16), NSERC (6799-427538-2012), the WD Armstrong Trust, and the NIHR Cambridge Biomedical Research Centre