Lamin A and microtubules collaborate to maintain nuclear morphology

Lamin A (LA) is a critical structural component of the nuclear lamina. Mutations within the LA gene (LMNA) lead to several human disorders, most striking of which is Hutchinson-Gilford Progeria Syndrome (HGPS), a premature aging disorder. HGPS cells are best characterized by an abnormal nuclear morphology known as nuclear blebbing, which arises due to the accumulation of progerin, a dominant mutant form of LA. The microtubule (MT) network is known to mediate changes in nuclear morphology in the context of specific events such as mitosis, cell polarization, nucleus positioning and cellular migration. What is less understood is the role of the microtubule network in determining nuclear morphology during interphase. In this study, we elucidate the role of the cytoskeleton in regulation and misregulation of nuclear morphology through perturbations of both the lamina and the microtubule network. We found that LA knockout cells exhibit a crescent shape morphology associated with the microtubule-organizing center. Furthermore, this crescent shape ameliorates upon treatment with MT drugs, Nocodazole or Taxol. Expression of progerin, in LA knockout cells also rescues the crescent shape, although the response to Nocodazole or Taxol treatment is altered in comparison to cells expressing LA. Together these results describe a collaborative effort between LA and the MT network to maintain nuclear morphology

Light-driven C-H bond activation mediated by 2D transition metal dichalcogenides

C-H bond activation enables the facile synthesis of new chemicals. While C-H activation in short-chain alkanes has been widely investigated, it remains largely unexplored for long-chain organic molecules. Here, we report light-driven C-H activation in complex organic materials mediated by 2D transition metal dichalcogenides (TMDCs) and the resultant solid-state synthesis of luminescent carbon dots in a spatially-resolved fashion. We unravel the efficient H adsorption and a lowered energy barrier of C-C coupling mediated by 2D TMDCs to promote C-H activation. Our results shed light on 2D materials for C-H activation in organic compounds for applications in organic chemistry, environmental remediation, and photonic materials

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Covert Communications with Extremely Low Power under Finite Block Length over Slow Fading

This paper investigates the achievable message transmission rate of covert communication over slow fading channels where the channel coefficient remains unchanged over a finite transmission block. Such communication is often implemented with an extremely low transmission power aiming to achieve low probability of detection by the eavesdropper and under tolerable probability of decoding error for the legitimate receiver. The exact expression of achievability and asymptotic covert bounds are derived, which are shown in accordance with the square root law in AWGN (Additive White Gaussian Noise) channels with large transmission blocks. The case that the eavesdropper has unknown channel state information is also studied in the paper

Study on the Risk Assessment Method of Rainfall Landslide

Quantitative risk assessment of landslides has always been the focus and difficulty in the field of landslide research. In this paper, taking Mayang County, Hunan Province as an example, the risk assessment of rainfall-induced landslides was carried out from the regional and individual scales. On the regional scale, the risk factors of geological disasters were analyzed. Based on the slope unit, the risk analysis of slope geological disasters and the vulnerability risk assessment of hazard-bearing bodies were carried out to form the block plan. On an individual scale, based on the analysis of rainfall extreme value, the variation law of landslide seepage field and stability under different rainfall recurrence periods was simulated. Then, the vulnerability of the disaster-bearing body was studied according to the analysis of the impact range and the field investigation. Combined with the evaluation results of landslide hazard and vulnerability of the disaster-bearing body, the life and economic risks under different working conditions were further obtained. Therefore, the research results could provide not only a reference for the risk assessment of rainfall-induced landslides in other regions but also a theoretical basis for the early warning and prediction of landslide disasters

Social distance of bystanders affects people’s embarrassment via changing fear of negative evaluation and feelings of attachment security

Abstract Background Embarrassment is a self-conscious emotion with important social functions, but it is not well understood. The perception of bystanders is considered a precondition for embarrassment, which makes it unique from other self-conscious emotions. Studies have shown that socially close bystanders can reduce individuals’ embarrassment. However, whether and how the embarrassment of individuals varies with the changes in social distance between them and their bystanders remained unclear, which indicates the key characteristics of embarrassment. Methods The current research consists of two studies. Study 1 tested whether participants’ embarrassment systematically varied with social distance by setting up three levels of social distance: close friends (i.e., short), casual friends (i.e., medium), and strangers (i.e., long), based on 159 participants. With two full mediation models, study 2 investigated whether and how the fear of negative evaluation and state attachment security mediated the influence of social distance on embarrassment based on 155 participants. Conclusions The current findings revealed that the social distance between bystanders and protagonists systematically influenced the embarrassment of protagonists and this effect occurred via two parallel pathways, i.e., by increasing the fear of negative evaluation and by reducing state attachment security. The findings not only showed the unique role of bystander characteristics on embarrassment, but also two cognitive processes behind this unique self-conscious emotion: fearing negative evaluation and seeking attachment for security

Short-term environmental nitrogen dioxide exposure and neurology clinic visits for headaches, a time-series study in Wuhan, China

Abstract Background Previous studies showed the adverse impacts of air pollution on headache attacks in developed countries. However, evidence is limited to the impact of exposure to air pollutants on headache attacks. In this study, we aimed to explore the impact of nitrogen dioxide (NO2) exposure on neurology clinic visits (NCVs) for headache onsets. Methods Records of NCVs for headaches, concentrations of ambient NO2, and meteorological variables were collected in Wuhan, China, from January 1st, 2017, to November 30th, 2019. A time-series study was conducted to investigate the short-term effects of NO2 exposure on daily NCVs for headaches. Stratified analyses were also computed according to season, age, and sex, and the exposure–response (E-R) curve was then plotted. Results A total of 11,436 records of NCVs for headaches were enrolled in our study during the period. A 10-μg/m3 increase of ambient NO2 corresponded to a 3.64% elevation of daily NCVs for headaches (95%CI: 1.02%, 6.32%, P = 0.006). Moreover, females aged less than 50 years of age were more susceptible compared to males (4.10% vs. 2.97%, P = 0.007). The short-term effects of NO2 exposure on daily NCVs for headaches were stronger in cool seasons than in warm seasons (6.31% vs. 0.79%, P = 0.0009). Conclusion Our findings highlight that short-term exposure to ambient NO2 positively correlated with NCVs for headaches in Wuhan, China, and the adverse effects varied by season, age, and sex