The Creation of Meaningful Situation: Study of Life Education Mode for Undergraduate Seed Teachers

As members of the first generation of universities seed teachers under the Project “Beyond 5.12” with life education, the authors discuss in this paper the creation of an educational situation on the basis of the situated cognition theory and the situational education mode, expecting that the second generation of undergraduate seed teachers can truly accept and agree with the idea of life education and promote their self-growth. Compared with the initial mode of the project, the current meaningful situation mode changes the roles, tasks and approaches of teachers and students, so that students’ subjectivity is strengthened and students can be better connected with others during the whole process. The present mode creates the meaning situation of life education and receives positive feedback from students

Numerical simulations of a ballistic spin interferometer with the Rashba spin-orbital interaction

We numerically investigate the transport behavior of a quasi one-dimension (1D) square loop device containing the Rashba spin-orbital interaction in the presence of a magnetic flux. The conductance versus the magnetic field shows the Al'tshuler-Aronov-Spivak (AAS) and Aharonov-Bohm (AB) oscillations. We focus on the oscillatory amplitudes, and find that both of them are strongly dependent on the spin precession angle (i.e. the strength of the spin-orbit interaction) and exhibit no-periodic oscillations, which are well in agreement with a recent experiment by Koga et al. [cond-mat/0504743(unpublished)]. However, our numerical results for the ideal 1D square loop device for the node positions of the amplitudes of the AB and AAS oscillations are found to be of some discrepancies comparing with quasi-1D square loop with a finite width. In the presence of disorder and taking the disorder ensemble average, the AB oscillation in the conductance will disappear, while the time-reversal symmetric AAS oscillation still remains. Furthermore, the node positions of the AAS oscillatory amplitude remains the same.Comment: 6 pages, 7 figure

Tuning the correlated color temperature of white LED with a guest-host liquid crystal

We demonstrate an electro-optic method to tune the correlated color temperature (CCT) of white light-emitting-diode (WLED) with a color conversion film, consisting of fluorescent dichroic dye doped in a liquid crystal host. By controlling the molecular reorientation of dichroic dyes, the power ratio of the transmitted blue and red lights of the white light can be accurately manipulated, resulting in different CCT. In a proof-of-concept experiment, we showed that the CCT of a yellow phosphor-converted WLED can be tuned from 3200 K to 4100 K. With further optimizations, the tuning range could be enlarged to 2500 K with fairly good color performance: luminous efficacy of radiation (LER) \u3e 300 lm/W, color rendering index (CRI) \u3e 75, and Duv \u3c 0.005. Besides, the operation voltage is lower than 5 V and good angular color uniformity is achieved with remote-phosphor coating. This approach is promising for next generation smart lighting

High‐Speed Large‐Field Multifocal Illumination Fluorescence Microscopy

Scanning optical microscopy techniques are commonly restricted to a sub‐millimeter field‐of‐view (FOV) or otherwise employ slow mechanical translation, limiting their applicability for imaging fast biological dynamics occurring over large areas. A rapid scanning large‐field multifocal illumination (LMI) fluorescence microscopy technique is devised based on a beam‐splitting grating and an acousto‐optic deflector synchronized with a high‐speed camera to attain real‐time fluorescence microscopy over a centimeter‐scale FOV. Owing to its large depth of focus, the approach allows noninvasive visualization of perfusion across the entire mouse cerebral cortex, not achievable with conventional wide‐field fluorescence microscopy methods. The new concept can readily be incorporated into conventional wide‐field microscopes to mitigate image blur due to tissue scattering and attain optimal trade‐off between spatial resolution and FOV. It further establishes a bridge between conventional wide‐field macroscopy and laser scanning confocal microscopy, thus it is anticipated to find broad applicability in functional neuroimaging, in vivo cell tracking, and other applications looking at large‐scale fluorescent‐based biodynamics

Monitoring mouse brain perfusion with hybrid magnetic resonance optoacoustic tomography

Progress in brain research critically depends on the development of next-generation multi-modal imaging tools capable of capturing transient functional events and multiplexed contrasts noninvasively and concurrently, thus enabling a holistic view of dynamic events in vivo. Here we report on a hybrid magnetic resonance and optoacoustic tomography (MROT) system for murine brain imaging, which incorporates an MR-compatible spherical matrix array transducer and fiber-based light illumination into a 9.4 T small animal scanner. An optimized radiofrequency coil has further been devised for whole-brain interrogation. System's utility is showcased by acquiring complementary angiographic and soft tissue anatomical contrast along with simultaneous dual-modality visualization of contrast agent dynamics in vivo

High performance liquid crystal displays with a low dielectric constant material

We report high performance liquid crystal displays (LCDs), including fringe field switching (p-FFS) and in-plane switching (p-IPS), with a small average dielectric constant (epsilon) but positive dielectric anisotropy material. Our low e based p-FFS and p-IPS LCDs offer several attractive properties, such as high transmittance, low operation voltage, fast response time (even at -20 degrees C), which is particularly desirable for outdoor applications of mobile or wearable display devices, and suppressed flexoelectric effect. Combining these advantages with the inherent outstanding features, such as wide viewing angle, no grayscale inversion, negligible color shift, and pressure resistance, the low e LC based p-FFS and p-IPS are strong contenders for next-generation mobile displays, and high resolution and high frame rate TVs

Volumetric optoacoustic neurobehavioral tracking of epileptic seizures in freely-swimming zebrafish larvae

Fast three-dimensional imaging of freely-swimming zebrafish is essential to understand the link between neuronal activity and behavioral changes during epileptic seizures. Studying the complex spatiotemporal patterns of neuronal activity at the whole-brain or -body level typically requires physical restraint, thus hindering the observation of unperturbed behavior. Here we report on real-time volumetric optoacoustic imaging of aberrant circular swimming activity and calcium transients in freely behaving zebrafish larvae, continuously covering their motion across an entire three-dimensional region. The high spatiotemporal resolution of the technique enables capturing ictal-like epileptic seizure events and quantifying their propagation speed, independently validated with simultaneous widefield fluorescence recordings. The work sets the stage for discerning functional interconnections between zebrafish behavior and neuronal activity for studying fundamental mechanisms of epilepsy and in vivo validation of treatment strategies

Detection of cerebral tauopathy in P301L mice using high-resolution large-field multifocal illumination fluorescence microscopy

Current intravital microscopy techniques visualize tauopathy with high-resolution, but have a small field-of-view and depth-of-focus. Herein, we report a transcranial detection of tauopathy over the entire cortex of P301L tauopathy mice using large-field multifocal illumination (LMI) fluorescence microscopy technique and luminescent conjugated oligothiophenes. In vitro assays revealed that fluorescent ligand h-FTAA is optimal for in vivo tau imaging, which was confirmed by observing elevated probe retention in the cortex of P301L mice compared to non-transgenic littermates. Immunohistochemical staining further verified the specificity of h-FTAA to detect tauopathy in P301L mice. The new imaging platform can be leveraged in pre-clinical mechanistic studies of tau spreading and clearance as well as longitudinal monitoring of tau targeting therapeutics

Environmental Flows for the Huron River System

This project aimed to provide the client, the Huron River Watershed Council (HRWC), with a framework for assessing flow alteration and its impact on the biological community of the Huron River. Within the watershed, analyses on annual, monthly, daily and sub-daily hydrological data, precipitation, land cover change, and fish and benthic invertebrate communities were conducted. Most hydrologic parameters concerning flow volume demonstrated an upward or non-changing pattern for the most recent 100 years. The base flow gradually increased, while the reversal number gradually decreased, suggesting a more stable flow regime. In terms of daily and sub-daily flow regime, the largest flashiness was demonstrated by the gauge near Ann Arbor, which could be the result of dam regulation in the upstream region. A strong correlation was found between precipitation and flow discharge. Both precipitation and flow discharge showed a similar increasing trend, while the runoff coefficient did not change significantly over time. This result implies that the increase in precipitation is a major driver of flow increase. With the current climate change trend, more water is expected in the river. Furthermore, increased impervious land in the watershed has resulted in more runoff from rainfall events and led to higher flashiness in the river. The corresponding increase of fine substrate and pollutants has also had a negative impact on stream habitats for benthic macroinvertebrates. At sample sites along the river, fish preferences (e.g. water temperature, stream size, substrate type, etc.) defined two guilds: riverine and impoundment. In impoundment environments, a high percentage of the sample taxa were: game fish, tolerant species, substrate generalists, piscivores and had preferences for larger rivers and slow current velocity. Conversely, in riverine environments, a high percentage of the sample taxa were: darters, intolerant species, insectivores, and had preferences for rock or gravel substrate and wider range of current velocities. Along the Huron River main stem, a habitat suitability model was used to predict expected fish communities at a given site and then compared to sampled fish communities. Fish communities around Ann Arbor and Ypsilanti were found to not be representative of model communities for the river type, temperature, and size. Present fish communities preferred a flow range with a significantly higher upper bound. An Adverse Resource Impact occurs in Ann Arbor at a low flow of around 45 cfs and in Ypsilanti at around 51 cfs. This serves as the critical low flow value for management purposes. Ann Arbor has the highest amount of historic ARI occurrences throughout the Huron River indicating that it is necessary to prioritize dam operations associated with this site.Master of ScienceNatural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/106564/1/Environ_Flows_Huron_River_2014.pd