Orbiting Light Around the Outer Surface of Dielectric Microspheres

Circulating light in the total internal reflection within dielectric spheres or disks is called the whispering gallery mode (WGM), which by itself is highly sensitive to its surface and capable of detecting viruses and single atomic ions. The detection site of the sensors using WGM is created by the evanescent light from the circulating light inside spheres. On the other hand, there have been no reports of observation or discussion of the light orbiting outside the surface of dielectric microspheres. Here we report light orbiting the outer surface of a dielectric microspheres different from the WGM. We observed anomalously enhanced Raman spectrum at the periphery of 3 μm diameter polystyrene (PS) microspheres on a silicon nitride (SiN) film using Raman microscopy. The wavelength intensity of this enhanced Raman spectrum was accompanied by periodic changes due to interference. These features may lead to the development of high-sensitive sensors and optical devices.

The global prevalence of depression, anxiety, stress and insomnia among general population during COVID-19 pandemic: A systematic review and meta-analysis

This study aimed to examine research findings related to depression, anxiety, stress, and insomnia during the COVID-19 pandemic. This study also explored periodic changes in the prevalence of depression, anxiety, stress, and insomnia among the general people during this pandemic. We performed a meta-analysis by searching articles from several sources (PubMed, MEDLINE, and GOOGLE SCHOLAR). We used the random-effects models, subgroup analysis, and heterogeneity test approaches. Results show that the prevalence of depression, stress, and insomnia increased during March to April 2020 (30.51%, 29.4%, and 25% respectively) compared to the study period before February 2020 (25.25%, 16.27%, and 22.63% respectively) and followed in May to June 2020 (16.47%, 5.1%, and 19.86 respectively). The prevalence of depression and anxiety from k= 30 studies was 28.18% (95% CI: 23.81-32.54), and 29.57% (95% CI: 24.67-34.47), respectively. And the prevalence of stress (k=13) was 25.18% (95% CI: 14.82 – 35.54) and the prevalence of insomnia (k=12) was 23.50% (95% CI: 16.44 – 30.57). These prevalence estimates during the pandemic are very high compared to normal times. Hence, the governments and policymakers should apply proven strategies and interventions to avoid psychological adversity and improve overall mental health during the COVID-19 pandemic.

Case Report: Two Cases of Abdominal Aggressive Fibromatosis That Mimicked Abdominal Wall Endometriosis and Review of Literature

Background: Abdominal aggressive fibromatosis (AF) can be confounded with abdominal wall endomentriosis (AWE) because they share considerable similarity. Because of the different patient prognoses and treatment strategies available, accurate pre-operative diagnosis is important.Case Presentation: We here report two cases of abdominal masses presenting as periodic changes in tumor sizes, which occurred in correlation with the menstrual cycle. The clinical findings were highly suggestive of AWE. However, the final pathological findings revealed AF. The estrogen receptor and progesterone receptor expressions were negative in the two cases. The differences between the two diseases have been discussed in detail.Conclusion: A diagnosis of AWE should be scrutinized closely if the patient does not complain of cyclic pain. Fine-needle aspiration cytology is a suitable tool for pre-operative evaluation.

First investigation of eclipsing binary KIC 9026766: analysis of light curve and periodic changes

We investigate a short-period W UMa binary KIC 9026766 with an orbital period of 0.2721278d in the Kepler field of view. By applying an automated q-search for the folded light curve and producing a synthetic light curve for this object based on the PHOEBE code, we calculate the fundamental stellar parameters. We also analyze the O − C curve of the primary minima. The orbital period changes can be attributed to the combination of an upward quadratic function and light-travel time effect (LTTE) due to a possible third body with a minimum mass of 0.029 M ⊙ and an orbital period of 972.5866 ±0.0041d. The relative luminosity of the primary and secondary eclipses (Min I − Min II) is calculated. The periodogram of the residuals of the LTTE and Min I − Min II show peaks with the same period of 0.8566d. The background effect of two nearby stars on our target is the possible reason for this signal. By considering the amplitudes and periods of the remaining signals in the O − C curve of minima, spot motion is possible.

A DOT1B/Ribonuclease H2 Protein Complex Is Involved in R-Loop Processing, Genomic Integrity, and Antigenic Variation in Trypanosoma brucei

Trypanosoma brucei is a unicellular parasite that causes devastating diseases like sleeping sickness in humans and the “nagana” disease in cattle in Africa. Fundamental to the establishment and prolongation of a trypanosome infection is the parasite's ability to escape the mammalian host's immune system by antigenic variation, which relies on periodic changes of a protein surface coat.

Experimental Study of Characteristics of Flow Field in Rod Bundle Channel Under Blocking Conditions

The rod bundle fuel is characterized by compact structure and narrow flow passage. The fragments and corrosion products, flowing with the coolant, can cause local blockage accident, threaten the integrity of the fuel cladding. Therefore, it is necessary to use the Particle Image Velocimetry (PIV) to visualize and measure the flow fields downstream of the blockages. The results show that partial blockages will cause flow reversal. In the backflow zone, vortices are generated downstream of the blockage, causing increase in the resistance. The length of backflow zone increases with the increase of the Reynolds number. The wake area formed downstream of the blockage presented periodic changes with the time and the period is about 0.8s. For the blockage of the interior subchannels, in the backflow zone, two rows of asymmetrically distributed vortices, and the vortices interfere with each other and cause squeeze deformation. For the blockage of the side and corner sub-channels, the formed vortices have irregular shape and nonuniformed distribution, and the flow field is more complex and changeable. This is believed to be caused by the high intensity turbulence and the influence of the wall.

Analysis of the Erosivity of High-Pressure Pulsating Water Jets Produced in the Self-Excited Drill Head

The dynamic impact of a water jet with a periodically changing structure can be used in various industries. The paper presents a design solution for a self-excited pulse head. This head can be used in mining for drilling holes and breaking rocks. The design of the head was developed based on computer simulations, which made it possible to learn the mechanism of impulse shaping inside the head. Tests of the water jet produced in the self-excited pulsation head showed the occurrence of periodic changes in its internal structure and pulsation frequency. A significant increase in the dynamic stream pressures was demonstrated for the head working in the water environment compared to the head working in the air environment For example, for nominal medium and highest pressures, this increase is up to 82%, while for the lowest pressures (10 MPa), the pressure force values increase by 46%. It was found that an increase in the nominal water pressure causes a decrease in the frequency of hydrodynamic pulses in the head operating in both the water and air environment.

Patch isolation and periodic environmental disturbances have idiosyncratic effects on local and regional population variabilities in meta-food chains

While habitat loss is a known key driver of biodiversity decline, the impact of other landscape properties, such as patch isolation, is far less clear. When patch isolation is low, species may benefit from a broader range of foraging opportunities, but are at the same time adversely affected by higher predation pressure from mobile predators. Although previous approaches have successfully linked such effects to biodiversity, their impact on local and metapopulation dynamics has largely been ignored. Since population dynamics may also be affected by environmental disturbances that temporally change the degree of patch isolation, such as periodic changes in habitat availability, accurate assessment of its link with isolation is highly challenging. To analyze the effect of patch isolation on the population dynamics on different spatial scales, we simulate a three-species meta-food chain on complex networks of habitat patches and assess the average variability of local populations and metapopulations, as well as the level of synchronization among patches. To evaluate the impact of periodic environmental disturbances, we contrast simulations of static landscapes with simulations of dynamic landscapes in which 30 percent of the patches periodically become unavailable as habitat. We find that increasing mean patch isolation often leads to more asynchronous population dynamics, depending on the parameterization of the food chain. However, local population variability also increases due to indirect effects of increased dispersal mortality at high mean patch isolation, consequently destabilizing metapopulation dynamics and increasing extinction risk. In dynamic landscapes, periodic changes of patch availability on a timescale much slower than ecological interactions often fully synchronize the dynamics. Further, these changes not only increase the variability of local populations and metapopulations, but also mostly overrule the effects of mean patch isolation. This may explain the often small and inconclusive impact of mean patch isolation in natural ecosystems.