Negative Optical Torque

Maxwell noted that light carries angular momentum, and as such it can exert torques on material objects. This was subsequently proved by Beth in 1936. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later enabled by the invention of laser. Novel and practical approaches for harvesting light for particle rotation have been demonstrated, where the structure is subjected to a positive optical torque along a certain axis21 if the incident angular momentum has a positive projection on the same axis. We report here a counter-intuitive phenomenon of negative optical torque, meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition. The optimal conditions are explored and explained.Comment: 15 pages, 3 figure

Spectroscopy of q3qˉ3\rm{q}^3\bar{\rm{q}}^3-States in Quark Model and Baryon-Antibaryon Enhancements

We study the mass spectrum of the $\rm{q}^3\bar{\rm{q}}^3$ mesons both from the quark model with triquark correlations and from common quark model with colormagnetic interactions and with relative S-waves between quarks. Two cluster configurations $(\rm{q}^3)-(\bar{\rm{q}}^3)$ and $(\rm{q}^2\bar{\rm{q}})-(\rm{q}\bar{\rm{q}}^2)$ are considered. In the spectrum we find rather stable states which have the same quantum number with particle resonances which are corresponding to the $p\bar{p}$ enhancement, $p\bar{\Lambda}$ enhancement and $\Lambda\bar{\Lambda}$ enhancement with spin-$\mathbf{0}$ or $\mathbf{1}$. This imply these enhancements are NOT experimental artifacts. The color-spin-flavor structures of $p\bar{p}$, $p\bar{\Lambda}$, and $\Lambda\bar{\Lambda}$ enhancements are revealed. The existence of spin-$\mathbf{1}$ $\Lambda\bar{\Lambda}, p\bar{\Lambda}, p\bar{p}$ enhancements is predicted.Comment: 45 pages, 5 figure

Deep learning based real-time facial mask detection and crowd monitoring

During the Covid pandemic, the importance of wearing mask has been noted globally. Additionally, crowded human clusters facilitated the transmission of the virus, which brings up the need for new systems for monitoring such situations. To address such issues, this research proposes an object recognition visual system based on deep learning to monitor the wearing of masks in a certain space and the control of the number of people indoors as an important tool during an epidemic. This research mainly investigates two types of identification. The first is to monitor whether people entering the site wear a mask at the entrance and exit of the field, and the second is to count the number of people entering a specific area. Experimental results show that by utilising the visual sensor, it is possible to detect and identify the people who frequently enter and exit in real-time. An advanced transfer learning approach has been employed to achieve the best discrimination performance. The actual training results prove that the migration learning Mask R-CNN algorithm produced by this method and the original Mask R-CNN algorithm have increased the mAP by 3%, reaching a mAP of 96%. In addition, the accuracy of the random sampling and identification in actual scenes has reached 92.1%. The developed deep learning vision system has an enhanced identification ability for the verification and analysis of actual scenes and has great application potential

Puerarin Induces Mitochondria-Dependent Apoptosis in Hypoxic Human Pulmonary Arterial Smooth Muscle Cells

Background: Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH) is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs), and to determine the possible underlying mechanisms. Methodology/Principal Findings: HPASMCs were cultured for 24 h in normoxia or hypoxia (5 % O2) conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123) fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 mM or more) intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. Conclusions/Significance: Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonar

Leukocyte nucleus segmentation and nucleus lobe counting

<p>Abstract</p> <p>Background</p> <p>Leukocytes play an important role in the human immune system. The family of leukocytes is comprised of lymphocytes, monocytes, eosinophils, basophils, and neutrophils. Any infection or acute stress may increase or decrease the number of leukocytes. An increased percentage of neutrophils may be caused by an acute infection, while an increased percentage of lymphocytes can be caused by a chronic bacterial infection. It is important to realize an abnormal variation in the leukocytes. The five types of leukocytes can be distinguished by their cytoplasmic granules, staining properties of the granules, size of cell, the proportion of the nuclear to the cytoplasmic material, and the type of nucleolar lobes. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency.Biomedical technologists can currently recognize abnormal leukocytes using human eyes. However, the quality and efficiency of diagnosis may be compromised due to the limitations of the biomedical technologists' eyesight, strength, and medical knowledge. Therefore, the development of an automatic leukocyte recognition system is feasible and necessary. It is essential to extract the leukocyte region from a blood smear image in order to develop an automatic leukocyte recognition system. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency.</p> <p>Results</p> <p>The purpose of this paper is to contribute an automatic leukocyte nuclei image segmentation method for such recognition technology. The other goal of this paper is to develop the method of counting the number of lobes in a cell nucleus. The experimental results demonstrated impressive segmentation accuracy.</p> <p>Conclusions</p> <p>Insensitive to the variance of images, the LNS (Leukocyte Nuclei Segmentation) method functioned well to isolate the leukocyte nuclei from a blood smear image with much better UR (Under Segmentation Rate), ER (Overall Error Rate), and RDE (Relative Distance Error). The presented LC (Lobe Counting) method is capable of splitting leukocyte nuclei into lobes. The experimental results illuminated that both methods can give expressive performances. In addition, three advanced image processing techniques were proposed as weighted Sobel operator, GDW (Gradient Direction Weight), and GBPD (Genetic-based Parameter Detector).</p

Analyzing experiences of using effective feedback in the ESL classroom through the use of digital technologies

This article of systematic literature review presents the analysis of a series of experiences that use effective feedback in educational activities through the use and integration of digital technologies, specifically, in the classes of English as a second language in higher education. The revision analyzed 14 different experiences. As part of the analysis, criteria are defined to describe and compare them, linked with the possibilities of feedback to favor the formative processes at the higher education level. Criteria include: country of origin and level of education, design of feedback used, the timing of the feedback, the means of providing feedback, and the consideration of digital technologies. The main results indicate that the use of feedback, in the ESL classroom, allows learners to boost their capacity of analysis, critical thinking, and the resolution of problems linked with interlanguage. As a conclusion, the salience and positive impact of digital technologies are highlighted in favoring the positive and effective feedback, in the particular case of English as a second language. Finally, it is evident the use of computer -mediation, screencast, and web-based learning environments as the primary sources of authors used more frequently to implement effective feedback in higher education. It concludes that the set of experiences analyzed provides light in terms of the considerations needed to design and adjust formative processes that allow boosting effective feedback mediated by digital technologies. As future work, there will be the elaboration of a methodological proposal that helps to adjust the formative processes that enable the integration of digital technologies as mediators in the process of feedback between teachers and learners.UCR::Sedes Regionales::Sede del Atlántico::Recinto de GuápilesUCR::Sedes Regionales::Sede del Carib

Oxytocin is implicated in social memory deficits induced by early sensory deprivation in mice

Acknowledgements We thank Miss Jia-Yin and Miss Yu-Ling Sun for their help in breading the mice. Funding This work was supported by grants from the National Natural Science Foundation of China (81200933 to N.-N. Song; 81200692 to L. Chen; 81101026 to Y. Huang; 31528011 to B. Lang; 81221001, 91232724 and 81571332 to Y-Q. Ding), Zhejiang Province Natural Science Foundation of China (LQ13C090004 to C. Zhang), China Postdoctoral Science Foundation (2016 M591714 to C.-C. Qi), and the Fundamental Research Funds for the Central Universities (2013KJ049).Peer reviewedPublisher PD

The Meq oncoprotein of Marek's disease virus interacts with p53 and inhibits its transcriptional and apoptotic activities

<p>Abstract</p> <p>Background</p> <p>Marek's disease virus (MDV) is an oncogenic herpesvirus, which causes malignant lymphoma in chickens. The Meq protein of MDV, which is expressed abundantly in MDV-infected cells and in Marek's disease (MD) tumor cells, functions as a transcriptional activator and has been proposed to play an important role in oncogenic transformation. Preliminary studies demonstrated that Meq is able to bind p53 <it>in vitro</it>, as demonstrated using a protein-binding assay. This observation prompted us to examine whether the interaction between Meq and p53 occurs in cells, and to investigate the biological significance of this interaction.</p> <p>Results</p> <p>We confirmed first that Meq interacted directly with p53 using a yeast two-hybrid assay and an immunoprecipitation assay, and we investigated the biological significance of this interaction subsequently. Exogenous expression of Meq resulted in the inhibition of p53-mediated transcriptional activity and apoptosis, as analyzed using a p53 luciferase reporter assay and a TUNEL assay. The inhibitory effect of Meq on transcriptional activity mediated by p53 was dependent on the physical interaction between these two proteins, because a Meq deletion mutant that lacked the p53-binding region lost the ability to inhibit p53-mediated transcriptional activity and apoptosis. The Meq variants L-Meq and S-Meq, but not VS-Meq and ∆Meq, which were expressed in MD tumor cells and MDV-infected cells, exerted an inhibitory effect on p53 transcriptional activity. In addition, ∆Meq was found to act as a negative regulator of Meq.</p> <p>Conclusions</p> <p>The Meq oncoprotein interacts directly with p53 and inhibits p53-mediated transcriptional activity and apoptosis. These findings provide valuable insight into the molecular basis for the function of Meq in MDV oncogenesis.</p

Accelerated induction of apoptosis in insect cells by baculovirus-expressed SARS-CoV membrane protein

AbstractIt has been shown that severe acute respiratory syndrome-associated coronavirus (SARS-CoV) 3a and 7a proteins, but not membrane (M) protein, induce apoptosis in mammalian cells. Upon expression of SARS-CoV M protein using the baculovirus/insect cell expression system, however, we found that the expressed M protein triggered accelerated apoptosis in insect cells, as characterized by rapid cell death, elevated cytotoxicity, cell shrinkage, nuclear condensation and DNA fragmentation. Conversely, the M protein expressed in mammalian cells did not induce apoptosis. This is the first report describing the induction of apoptosis by SARS-CoV M protein in animal cells and possible implications are discussed