With the nationwide emphasis on improving outcomes for STEM undergraduates, it is important that we not only focus on modifying classroom instruction, but also provide students with the tools to ...maximize their independent learning time. There has been considerable work in laboratory settings examining two beneficial practices for enhancing learning: spacing and self-testing. In the current study, we examine biology students' study practices, particularly in the context of these two behaviors. We specifically investigate whether a light-touch study skills intervention focused on encouraging spacing and self-testing practices impacted their utilization. Based on pre- and post-course surveys, we found that students report utilizing both beneficial and ineffective study practices and confirm that usage of spacing and self-testing correlates with a higher course grade. We also found that students in the section of the course which received the study skills intervention were more likely to report continued use or adoption of spacing and self-testing compared to students in control sections without the intervention. Surprisingly, we found that underrepresented minorities (URMs) under-utilize self-testing, and that our intervention helped to partially ameliorate this gap. Additionally, we found that URMs who reported self-testing earned similar course grades compared to non-URMs who also self-tested, but that there was a much larger drop in performance for URMs who did not self-test relative to non-URMs who also did not self-test. Overall, we would encourage instructors to dedicate class time towards discussing the merits of beneficial study practices, especially for students that have historically underperformed in STEM disciplines.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Purge tube was found to be a major source of CO during the heating stage.•New contamination model in which H2O is involved in CO generation was proposed.•Effect of reaction between CO and ...solid-state silicon feedstock was discussed.
A new carbon contamination model in which carbon monoxide (CO) generated by the chemical reaction between H2O and graphite components during the heating stage can react with the solid-state silicon feedstock was proposed. The influence of CO on carbon concentration during the heating stage in a laboratory-scale Czochralski furnace was investigated using a quadrupole mass spectrometer. A strong peak of CO and H2O partial pressure was observed before the silicon feedstock began to melt. We believe that the purge tube is a major source of CO during the heating stage because carbon contamination of the order of 1016 occurred in the silicon melt by CO generated from the purge tube. Furthermore, we discussed the impact of the SiC film formed on the surface of the silicon feedstock on carbon contamination.
In the decommissioning work for concrete walls of PET-cyclotron rooms, an in-situ measurement is expected to be useful for obtaining a contour map of the specific activity on the walls without ...destroying the structure. In this study, specific activities of γ-ray-emitting radionuclides in concrete walls were determined by using an in-situ measurement method employing a portable Ge semiconductor detector, and compared with the specific activity obtained using the sampling measurement method, at the Medical and Pharmacological Research Center Foundation in Hakui, Ishikawa, Japan. Accordingly, the specific activity could be determined by the in-situ determination method. Since there is a clear correlation between the total specific activity of γ-ray-emitting radionuclides and contact dose rate, the specific activity can be determined approximately by contact dose-rate measurement using a NaI scintillation survey meter. The specific activity of each γ-ray-emitting radionuclide can also be estimated from the contact dose rate using a NaI scintillation survey meter. The in-situ measurement method is a powerful tool for the decommissioning of the PET cyclotron room.
RX J0046.5−7308 is a shell-type supernova remnant (SNR) in the Small Magellanic Cloud (SMC). We carried out new 12CO(J = 1-0, 3-2) observations toward the SNR using Mopra and the Atacama ...Submillimeter Telescope Experiment. We found eight molecular clouds (A-H) along the X-ray shell of the SNR. The typical cloud size and mass are ∼10-15 pc and ∼1000-3000 M☉, respectively. The X-ray shell is slightly deformed and has the brightest peak in the southwestern shell where two molecular clouds A and B are located. The four molecular clouds A, B, F, and G have high intensity ratios of 12CO(J = 3-2)/12CO(J = 1-0) > 1.2, which are not attributable to any identified internal infrared sources or high-mass stars. The H i cavity and its expanding motion are found toward the SNR, which are likely created by strong stellar winds from a massive progenitor. We suggest that the molecular clouds A-D, F, and G and H i clouds within the wind-blown cavity at VLSR = 117.1-122.5 km s−1 are associated with the SNR. The X-ray spectroscopy reveals the dynamical age of yr and the progenitor mass of 30 M☉, which is also consistent with the proposed scenario. We determine physical conditions of the giant molecular cloud LIRS 36A using the large velocity gradient analysis with archival data sets of the Atacama Large Millimeter/submillimeter Array; the kinematic temperature is K and the number density of molecular hydrogen is cm−3. The next generation of γ-ray observations will allow us to study the pion-decay γ-rays from the molecular clouds in the SMC SNR.
We carried out new 12CO(J = 1-0, 3-2) observations of a N63A supernova remnant (SNR) from the LMC using the Atacama Large Millimeter/submillimeter Array (ALMA) and Atacama Submillimeter Telescope ...Experiment. We find three giant molecular clouds toward the northeast, east, and near the center of the SNR. Using the ALMA data, we spatially resolved clumpy molecular clouds embedded within the optical nebulae in both the shock-ionized and photoionized lobes discovered by previous H and S ii observations. The total mass of the molecular clouds is ∼800 M☉ for the shock-ionized region and ∼1700 M☉ for the photoionized region. Spatially resolved X-ray spectroscopy reveals that the absorbing column densities toward the molecular clouds are ∼(1.5-6.0) × 1021 cm−2, which are ∼1.5-15 times less than the averaged interstellar proton column densities for each region. This means that the X-rays are produced not only behind the molecular clouds, but also in front of them. We conclude that the dense molecular clouds have been completely engulfed by the shock waves, but have still survived erosion owing to their high density and short interacting time. The X-ray spectrum toward the gas clumps is well explained by an absorbed power-law model or a high-temperature plasma model, in addition to thermal plasma components, implying that the shock-cloud interaction is efficiently working for both cases through the shock ionization and magnetic field amplification. If the hadronic gamma-ray is dominant in the GeV band, the total energy of the cosmic-ray protons is calculated to be ∼(0.3-1.4) × 1049 erg, with an estimated interstellar proton density of ∼190 90 cm−3, containing both the shock-ionized gas and neutral atomic hydrogen.
Hypocretins/orexins are neuropeptides implicated in sleep regulation and the sleep disorder narcolepsy. In order to examine how hypocretin activity fluctuates across 24 h with respect to the ...sleep–wake cycle, we measured changes in extracellular hypocretin‐1 levels in the lateral hypothalamus and medial thalamus of freely moving rats with simultaneous sleep recordings. Hypocretin levels exhibited a robust diurnal fluctuation; levels slowly increased during the dark period (active phase), and decreased during the light period (rest phase). Levels were not correlated with the amount of wake or sleep in each period. Although an acute 4‐h light‐shift did not alter hypocretin levels, 6‐h sleep deprivation significantly increased hypocretin release during the forced‐wake period. Hypocretin activity is, thus, likely to build up during wakefulness and decline with the occurrence of sleep. These findings, together with the fact that a difficulty in maintaining wakefulness during the daytime is one of the primary symptoms of hypocretin‐deficient narcolepsy, suggest that hypocretin activity may be critical in opposing sleep propensity during periods of prolonged wakefulness.
This paper reports the spectroscopic performance improvement of the silicon-on-insulator (SOI) pixel detector for X-ray astronomy, by introducing a double-SOI (D-SOI) structure. For applications in ...X-ray astronomical observatories, we have been developing a series of monolithic active pixel sensors, named as “XRPIXs,” based on SOI pixel technology. The D-SOI structure has an advantage that it can suppress a parasitic capacitance between the sensing node and the circuit layer, due to which the closed-loop gain cannot be increased in our conventional XRPIXs with a single-SOI (S-SOI) structure. Compared to the S-SOI XRPIX, the closed-loop gain is doubled in the D-SOI XRPIX. The readout noise is effectively lowered to 33% (16 e− (rms)), and the energy resolution at 6.4 keV is improved by a factor of 1.7 (290 eV in FWHM). The suppression of the parasitic capacitance is also quantitatively evaluated based on the results of capacitance extraction simulation from the layout. This evaluation provides design guidelines for further reduction of the readout noise.
Rigid polyurethane (PU) foams having saccharide and castor oil structures in the molecular chain were prepared by reaction between reactive alcoholic hydroxyl group and isocyanate. The apparent ...density of PU foams was in a range from 0.05 to 0.15 g cm
−3
. Thermal properties of the above polyurethane foams were studied by differential scanning calorimetry, thermogravimetry and thermal conductivity measurement. Glass transitions were observed in two steps. The low-temperature side glass transition was observed at around 220 K, regardless of castor oil content. This transition is attributed to the molecular motion of alkyl chain groups of castor oil. The high-temperature side glass transition observed in the temperature range from 350 to 390 K depends on the amount of molasses polyol content. The high-temperature side glass transition is attributed to the molecular motion of saccharides, such as sucrose, glucose, fructose as well as isocyanate phenyl rings, which act as rigid components. Thermal decomposition was observed in two steps at 570 and 620–670 K. Thermal conductivity was observed at around 0.032 J sec
−1
m
−1
K
−1
. Compression strength and modulus of PU foams were obtained by mechanical test. It was confirmed that the thermal and mechanical properties of PU foams could be controlled by changing the mixing ratio of castor oil and molasses for suitable practical applications.
Digital nerve block is a common procedure with several techniques, including the traditional digital nerve block, transthecal digital nerve block, and single subcutaneous palmar digital nerve block. ...This review aimed to evaluate the efficacy of these three methods. A systematic search was performed in the PubMed, Scopus, and Cochrane Library databases. The risk of bias of the studies was assessed using the Cochrane Collaboration's tool for assessing the risk of bias and the Risk of Bias Assessment Tool for Non-Randomized Studies. Fourteen prospective randomized controlled studies and one prospective comparative study were included. The three methods of digital block showed similar onset times, durations, injection pain and incidence of incomplete anesthesia. This review confirmed that all three methods of digital block are equally effective. Considering that patients prefer a single injection and the potential risk of complications, the single subcutaneous digital block could be more widely used.
Le bloc nerveux digital est une technique courante avec plusieurs variantes, notamment le bloc nerveux digital traditionnel, le bloc nerveux digital transthécal et le bloc nerveux digital palmaire simple sous-cutané. Cette étude visait à évaluer l’efficacité de ces trois méthodes. Une recherche systématique a été effectuée dans les bases de données PubMed, Scopus et Cochrane Library. Le risque de biais des études a été évalué à l’aide de l’outil d’évaluation du risque de partialité de la Cochrane Collaboration et de l’outil d’évaluation du risque de partialité pour les études non randomisées. Quatorze études prospectives randomisées et contrôlées et une étude comparative prospective ont été incluses. Les trois méthodes de bloc digital ont montré des temps d’installation, des durées, des douleurs à l’injection et des incidences d’anesthésie incomplète similaires. Cette étude a confirmé que les trois méthodes du bloc digital sont aussi efficaces les unes que les autres. Étant donné que les patients préfèrent une seule injection et vu le risque potentiel de complications, le bloc digital sous-cutané unique pourrait être utilisé plus largement.
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