Search

Abstract Objective To explore the impact on Taiwanese parents and children following an outbreak of the Omicron variant during the COVID-19 pandemic. Methods Data were collected following class cancellations mandated by the Ministry of Education due to an outbreak of the Omicron variant of COVID-19 in April 2022. A national parent organization developed self-report survey questionnaire, “Impact of the Pandemic-related School Closures/Class Cancellations” (IPRSCCC), assessed parents’ perceived impact of school cancellations on their child/children’ and on their adaptation. The online survey was available between May 4 and May 9, 2022, in 20 districts throughout Taiwan. Results A total of 2126 parents representing 2592 children responded. Total scores on the IPRSCCC were significantly higher for parents of children whose classes were cancelled (n = 891) compared with parents whose children continued in-person classes (n = 1053). Parents perceived the class cancellations of the child/children disrupted daily routine, learning loss and impacted academic motivation. They also reported emotional stress and no time for rest, which were associated with parental burnout. However for these parents, there were no significant differences in scores between parents living in low and high socioeconomic areas. Only the subscale score for disrupted daily routine was significantly higher for fathers, and emotional stress was significantly higher for parents with two, or ≥ 3 children. When academic impacts were examined using national examination scores for 12th grade students, the percent of students with scores of ≤ 6 in English, Chinese, and mathematics was higher in 2022 than in 2020. Conclusions Higher IPRSCCC scores for parents of children whose classes were cancelled provides additional evidence of the impact of disruptions of in-person classes due to the COVID-19 pandemic. Examination scores confirmed class cancellations impacted academic performance.

Abstract We assess the orbit accuracy and time synchronization error using the L1 and C1 observables during the different solar activities. In general, GPS single-frequency (SF) observable can be used for commercial applications in satellite industry. The accuracy of satellite orbit determination using the SF observations is dominated by solar activities. The solar activities are indexed by the F10.7 value. The different solar activities lead to the ionosphere perturbation, triggering off the occurrence probability of ionospheric irregularities. The ionospheric irregularity affects the amplitude and phase of GPS signal. The affected amplitude and phase are indexed by the S4 value. We determine the GRACE satellite orbit using the SF GPS observations and compare the resulting orbit to that derived by dual-frequency observations for the effectiveness. The SF phase data are very sensitive to the variation in electron density and indirectly affects both the orbit accuracy and the time synchronization error. This is most likely caused by the phase ambiguity disturbed by the ionosphere. However, the C1 is relatively free from such a disturbance due to the strong signal-to-noise ratio (SNR) and the phase shift keying technique. The C1 performs the consistent solution over the low and high solar activities. However, this is not the case for the L1. The L1-derived orbit solution during the high solar activities is worse than that during the low solar activities. On the other hand, the time synchronization errors derived by the L1 and C1 are also different. The L1-derived time synchronization error has a relatively large perturbation as compared to the C1-derived one, which shows a consistent solution for a long-term period. This work suggests that the C1 observable is able to produce a consistent the orbit solution and time synchronization for the commercial applications of the satellite industry. Graphical Abstract

Key points (1) Electron density profiles data service of FORMOSAT-7/COSMIC-2. (2) Absolute TEC data service of FORMOSAT-7/COSMIC-2. (3) Validation results confirms the data is ready to use.

BackgroundTaiwan faced a surge of COVID-19 infections in May 2021. Because new cases were quickly increasing, parents called for school closures. A national parent group used an online survey to collect opinions about upcoming school closings planned by the Ministry of Education. This study evaluated the results of the survey for all respondents and investigated the level of viral transmission following school closures among students in Taiwan.MethodsAn online survey titled “Survey of Opinions of School Closures during the Current COVID-19 Outbreak” (SOSC-COVID-19) was designed by the national parent association and then distributed to members of the community throughout Taiwan via local parent groups from May 17 to 18, 2021. The survey included an open-ended respondents' opinions about school closures. Differences among regions and socioeconomic scores (SES) were analyzed with chi-square tests.ResultsA total of 8,703 completed survey forms data were analyzed. Nearly all respondents (7,973, 91.6%) approved of school closures; there were no differences of opinions inside and outside municipalities or by regional SES scores. Only 8.4% of respondents were opposed to any type of school closure, believing parents should decide whether their child attended school, which also did not vary with region or SES score. Qualitative feedback from parent and teacher responders indicated students' health and economic impacts were additional concerns that influenced their choice of whether the government or parents should decide about school closures. On the afternoon of May 18, 2021, the government of Taiwan closed all schools. Although a spike in new cases of COVID-19 occurred among students 10 days after school closures, over the next 40 days new cases declined, falling to zero by July 5th.ConclusionsDespite the inability of nationwide school closures to completely halt transmission of the virus within families during the COVID-19 outbreak, school closures helped to impede transmission between students.

A compact beam-position monitor was constructed using a linear contact image sensor attached to a plastic scintillator and tested using a 230 MeV proton beam. The results indicate that the beam position can be obtained in real-time, and the beam position with a precision of up to 0.03 mm. The compactness and high precision of the device hold considerable potential for it to be used as a beam-position monitor and offline, daily quality assurance monitor in hadron therapy. • The method can provide a high precision and high resolution beam position for flash irradiation in particle therapy in real-time. • The method using contact image sensor with scintillator does not require a long focal length for camera and it is free of image distortion. • The method can be integrated into medical particle accelerator for feedback control and daily quality assurance.

Abstract We report in this paper a new MRI contrast agent based on magnetic nanodiamonds fabricated by Fe ion implantation. The Fe atoms that are implanted into the nanodiamonds are not in direct contact with the outside world, enabling this new contrast agent to be free from cell toxicity. The image enhancement was shown clearly through T2 weighted images. The concentration dependence of the T2 relaxation time gives a relaxivity value that is about seven times that of the regular non-magnetic nanodiamonds. Cell viability study has also been performed. It was shown that they were nearly free from cytotoxicity independent of the particle concentration used. The imaging capability demonstrated here adds a new dimension to the medical application of nanodiamonds. In the future one will be able to combine this capability of magnetic nanodiamonds with other functions through surface modifications to perform drug delivery, targeted therapy, localized thermal treatment and diagnostic imaging at the same time.

Taiwan is located at the land-sea interface in a subtropical region. Because the climate is warm and moist year round, there is a large and highly variable amount of water vapor in the atmosphere. In this study, we calculated the Zenith Wet Delay (ZWD) of the troposphere using the ground-based Global Positioning System (GPS). The ZWD measured by two Water Vapor Radiometers (WVRs) was then used to verify the ZWD that had been calculated using GPS. We also analyzed the correlation between the ZWD and the precipitation data of these two types of station. Moreover, we used the observational data from 14 GPS and rainfall stations to evaluate three cases. The offset between the GPS-ZWD and the WVR-ZWD ranged from 1.31 to 2.57 cm. The correlation coefficient ranged from 0.89 to 0.93. The results calculated from GPS and those measured using the WVR were very similar. Moreover, when there was no rain, light rain, moderate rain, or heavy rain, the flatland station ZWD was 0.31, 0.36, 0.38, or 0.40 m, respectively. The mountain station ZWD exhibited the same trend. Therefore, these results have demonstrated that the potential and strength of precipitation in a region can be estimated according to its ZWD values. Now that the precision of GPS-ZWD has been confirmed, this method can eventually be expanded to the more than 400 GPS stations in Taiwan and its surrounding islands. The near real-time ZWD data with improved spatial and temporal resolution can be provided to the city and countryside weather-forecasting system that is currently under development. Such an exchange would fundamentally improve the resources used to generate weather forecasts.

The Global Positioning System (GPS) radio occultation (RO) technique has been used to receive multi-channel GPS carrier phase signals from low Earth or biting (LEO) satellites and demon strate active limb sounding of the Earth¡¦s ionosphere. Apply ing Abel inversion through compen sated total electron content (TEC) values, the GPS RO observations can obtainion o spheric electron density (ne) profiles and then scale F2-layer characteristics including foF2 and hmF2, especially, hmF2 that can not be directly deduced from ionosonde observations. From the GPS/MET and FS3/COS MIC mis sions, we can col lect on average two hundred and eighteen hundred vertical neprofiles, respectively, within one day. The retrieved foF2 and hmF2 re sults have been used to produce numerical maps representing complex prop erties on a world-wide scale. This paperpresents aphysically appeal ing represen tation of foF2 and hmF2 medians based on GPS RO data. The derived numerical maps have also been examined by ground-based ionosonde data.

Multi-channel Global Position System (GPS) carrier phase signals received by the FormoSat-3 (FS3)/COSMIC program's six low Earth orbiting (LEO) satellites were used to undertake active limb sounding of the Earth¡¦s atmosphere and ionosphere via radio occultation (RO). In this study, the effects of large-scale horizontal gradients and/or inhomogeneous ionospheric electron densities (ne) were considered by developing an iterative scheme to determine "compensated" total electron content (TEC) values through nearby occultation observations. Using an iterative Abel inversion through "compensated" TEC values, more than one-hundred and eighty thousand vertical ionospheric ne profiles were collected during the intense observation period (IOP) of 20 June - 27 September (day number 171 to 270) 2006. Coincidences of GPS RO observations to ionospheric ne ionosonde data from forty-nine worldwide stations have been examined. It is found that the iterative scheme gives improved retrievals over the standard Abel inversion. From several thousand matches within the IOP experiment, the root mean square (rms) foF2 differences between the ionosonde measurements and the FS3/COSMIC retrievals are improved from 1.67 to 1.07 MHz. The results also show improvement in the overestimates (underestimates) on low (high) retrieved foF2s, while the obtained hmF2s give better agreement with ionosonde observations.

Equatorial plasma bubbles (EPBs) are plasma depletions that can occur in the nighttime ionospheric F region, causing scintillation in satellite navigation and communications signals. Past research has shown that EPB occurrence rates are higher during the equinoxes in most longitude zones. An exception is over the central Pacific and African sectors, where EPB activity has been found to maximize during solstice. Tsunoda et al. (2015) hypothesized that the solstice maxima in these two sectors could be driven by a zonal wavenumber 2 atmospheric tide in the lower thermosphere. In this study, we utilize satellite observations to examine evidence of such a wave-2 feature preconditioning the nighttime ionosphere to favor higher EPB growth rates over these two regions. We find the postsunset total electron content (TEC) observed by FORMOSAT-3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) during boreal summer from 2007 to 2012 exhibits a wave-2 zonal distribution, consistent with elevated vertical plasma gradients favorable for EPB formation. Numerical experiments are also carried out to determine whether such an ionospheric wave-2 can be produced as a result of vertical coupling from atmospheric tides with zonal wavenumber 2 in the local time frame. We find that forcing from these tidal components produced increases in the Rayleigh-Taylor growth rate over both sectors during solar maximum and minimum, as well as wave-2 modulations on vertical ion drift, ion flux convergence, and nighttime TEC. Our results are consistent with the aforementioned hypothesis over both regions with vertical coupling effects from atmospheric tides preconditioning the nighttime ionosphere to favor higher EPB growth rates. [ABSTRACT FROM AUTHOR]

Beginning in 2006, four ground stations located at Chung-Li (25.136°N, 121.539°E), TasoTun (23.981°N, 120.697°E), CheCheng (22.725°N, 120.544°E), and tropical Itu Aba Island (10.06°N, 114.350°E) were set up to receive beacon signals from six FORMOSAT-3/COSMIC (Bernhardt et al. 2000) and other NNSS-like satellites. By applying differential Doppler technique on three quadrature components of the three-band beacon signals, we were able to obtain total electric contents (TEC) values and scintillation along the radio path through the ionosphere. Such measurements can be used to derive regional ionospheric irregularity and tomography. In this paper, we have confirmed the power patterns contributed from the transmitting antennas on board FS3/COSMIC and the ground-based receiving antennas. The multiplicative algebraic reconstruction technique (MART) algorithm has also been implemented to reconstruct ionospheric tomography images. Observations of the diurnal variations and the dynamics of equatorial anomaly showed that the equatorial anomaly appeared at 0800 LT, and then subsequently moved toward the Earth's poles. The north crest was strongest at ~1300 LT and its core was located at about 10°N of the magnetic latitude (~20°N geographic latitude). Afterwards, the crest moved toward the equator after sunset and disappeared after midnight. [ABSTRACT FROM AUTHOR]

In 2004, a NOAA (National Oceanic and Atmospheric Administration) MF/HF radar or dynasonde was set up by the National Central University in Chung-Li (24.5°N, 121.0°E), Taiwan. The Chung-Li dynasonde employs an interferometric array (including four receivers) for receiving ionospherically reflected echoes, and is a fully digital research ionosonde, capable of providing high precision spatial and temporal ionospheric measurements. Utilizing a pulse set defined by four pulses transmitted at two closely spaced frequencies, the measured parameters are the time-of-flight and sixteen complex-amplitudes. Two types of observations are conducted by the Chung-Li dynasonde -- an active sounding mode and a passive sounding mode. The methods are utilized in observing the local ionosphere and RF environment above Chung-Li. The active sounding is capable of transmitting HF radio pulses for remote sensing of the ionosphere. Initial results from this study have revealed various special events for observing sporadic E and spread F, along with the distribution of foF2 in a single day. These initial results will be used to confirm the surveillance of the ionosphere from other instruments, and conduct statistical comparisons between seasons. On the other hand, passive sounding receives and records signals from RF environments. It is used to monitor the MF/HF band in real time, and is contrasted with the active results when the echo is weak. [ABSTRACT FROM AUTHOR]

Although nanodiamonds have long being considered as a potential tool for biomedical research, the practical in vivo magnetic resonance imaging (MRI) application of nanodiamonds remains relatively unexplored. In this paper, we present the first application of in vivo MRI contrast enhancement using only iron embedded magnetic nanodiamonds. An MR image enhancement was clearly demonstrated in the rendering of T2-weighted images of mice obtained using an unmodified commercial MRI scanner. The excellent contrast obtained using these nanodiamonds opens the door to the non-invasive in vivo tracking of nanodiamonds and image enhancement. In the future, one can apply these magnetic nanodiamonds together with surface modifications to facilitate drug delivery, targeted therapy, localized thermal treatment, and diagnostic imaging. [ABSTRACT FROM AUTHOR]