The \u3ci\u3eDrosophila\u3c/i\u3e T-box Transcription Factor Midline Functions Within the Notch-Delta Signaling Pathway To Specify Sensory Organ Precursor Cell Fates and Regulates Cell Survival Within the Eye Imaginal Disc

We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch-Delta signaling pathway essential for specifying the fates of sensory organ precursor (SOP) cells. These findings complement an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in unique neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch-Delta signaling hierarchy and is essential for maintaining cell viability by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. © 2013 Elsevier Ireland Ltd

First results of ground-based optical measurements of the ion-neutral coupling within the polar region.

&amp;lt;div dir=&amp;quot;auto&amp;quot;&amp;gt;Ground-based imaging Fabry-Perot interferometer (FPI) optical measurements of the ion-neutral coupling between the F-region plasma and the polar thermosphere were made during the 2022-2023 northern winter season at the Kjell Henriksen Observatory (78.2 N, 15.6 E). By observing in sequence with a filter wheel located in front of the etalon, measurements of the spectral profiles of both the O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; 732 nm emission and the O 630 nm emission for each direction selected by a double axis mirror system were used to determine Doppler shifts and Doppler broadenings. The 732 O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; results were analyzed to determine the averaged line-of-sight F-region drift speed and ion temperature for a typical exposure time of 120 s.&amp;amp;#160; For the 630 nm O emission, the averaged line-of-sight wind speed and neutral temperature were determined for an exposure time of 30 s. The FPI clear aperture was 120 mm, the FPI etalon gap separation was 1.4925 cm, each filter bandwidth was ~0.8 nm, and the focal length for an apochromatic lens assembly was 300 mm enabling the imaging observations of 12 rings for the 630 nm O emission and 11 rings for the 732 nm O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; emission. The primary production excitation source of the observed 732 nm O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; emission was that of solar EUV photoionization but the soft particle energetic precipitation associated with the polar cusp region also contributed significantly to the production of both emissions, especially during the noon sector period. Contamination by the 1PG molecular band emission of N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; was generally non-existent. It was found there was sufficient O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; emission for almost all directions chosen to determine the line-of-sight ion drift and ion temperatures with reasonable accuracy. Contamination of the O&amp;lt;sup&amp;gt;+ &amp;lt;/sup&amp;gt;732 emission by the 731.6 nm OH doublet&amp;amp;#160; associated with the OH hyperfine structure caused by lambda splitting was always present in each O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; observed spectral profile. Removal of this emission in the analysis proved to be straightforward as one of the two OH peaks is seen clear of the O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; spectral profile, and its intensity could be used after the step of annular summing to normalize the OH structure for removal from the composite ring-integrated interferometric spectral profile. The two peaks of the O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; 732 nm doublet were almost coincident within each interferogram order. Results will be analyzed: 1), to search for indications of anti-sunward drift of the F-region plasma, 2) to determine the degree of variability of the observed plasma drifts, and 3) to determine the extent of Joule heating creating differences between the ion and neutral temperatures. The data obtained in the magnetic zenith direction will be examined to search for evidence of possible ion outflow.&amp;lt;/div&amp;gt; &amp;lt;div dir=&amp;quot;auto&amp;quot;&amp;gt;&amp;amp;#160;&amp;lt;/div&amp;gt;</jats:p

Comparative Analysis of the Measured and Modeled Equatorial Thermospheric Wind Climatology&amp;#160;

&amp;lt;p&amp;gt;The thermospheric winds play an important role in the vertical and horizontal couplings of the upper atmosphere by modulating neutral and plasma dynamics. A large variety of observation techniques and numerical as well as empirical models have been developed to understand the behavior of thermospheric winds. The Fabry-Perot interferometer (FPI) is a widely used ground- and satellite-based optical instrument for the thermospheric winds observations in the upper atmosphere. Due to solar contamination of the fainter airglow emission during the daytime, most of the ground-based interferometric wind measurements are limited to the nighttime period only. Despite these constraints, the Second&amp;amp;#8208;generation, Optimized, Fabry&amp;amp;#8208;Perot Doppler Imager (SOFDI) is designed for both daytime and nighttime measurements of thermospheric winds from OI 630&amp;amp;#8208;nm emission and is currently operating at the Huancayo, Peru, near the geomagnetic equator.&amp;amp;#160;In this study, we present a comparative analysis of the observed SOFDI wind climatological data and several other modeled results including, but not limited to, Horizontal Wind Model 2014 (HWM-14), Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics (CTIPe) model with and without implementing Prompt Penetration Electric Field (PPEF), Whole Atmosphere Model (WAM), SAMI3 model, and Magnetic mEridional NeuTrAl Thermospheric (MENTAT) model. We examine the relative performances of these models in the context of the direct-measured thermospheric winds. The day and nighttime modeled winds show an excellent agreement with the SOFDI wind data at the equatorial latitude, except for the daytime zonal winds. Further, this analysis gives a comprehensive picture of how well the measured winds provided by the SOFDI instrument and various models represent the features of the equatorial thermosphere.&amp;amp;#160;We also investigate and give an overview of the sources, drivers, effects, and possible mechanisms of the wind variability in the low-latitude thermosphere.&amp;lt;/p&amp;gt;</jats:p

Short Wave Infrared Imaging for Auroral Physics and Aeronomy Studies

Advances in solar-terrestrial physics are generally linked to the development of innovative new sensor technologies, affording us ever better sensitivity, higher resolution, and broader spectral response. Recent advances in low-noise InGaAs sensor technology have enabled the realization of low-light-level scientific imaging within the short-wave infrared (SWIR) region of the electromagnetic spectrum. This paper describes a new and highly sensitive ultra-wide angle imager that offers an expansion of auroral and airglow imaging capabilities into the SWIR spectral range of 900–1,700 nm. The imager has already proven successful in large-area remote sensing of mesospheric temperatures and in providing intensity maps showing the propagation and dissipation of atmospheric gravity waves and ripples. The addition of an automated filter wheel expands the range of applications of an already versatile SWIR detector. Several potential applications are proposed herein, with an emphasis on auroral science. The combined data from this type of instrument and other existing instrumentation holds a strong potential to further enhance our understanding of the geospace environment

Interferometric measurements of the [lambda] 7319 A doublet emissions of OII

Fabry-Perot interferometer observations of the OII 7319 A line made from College, Alaska are presented. Significant Doppler shifts corresponding to the ion drift motion, caused by the convection electric fields, were observed under special conditions, but no steady observations were possible due to the sporadic nature of this emission. Very preliminary results of the observed doublet separation ([approximate]0.836 A) are also presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22389/1/0000838.pd

Noncontrast MRI with advanced diffusion weighted imaging for breast cancer detection in a lactating woman.

Magnetic resonance imaging (MRI) is used for preoperative evaluation, high-risk screening, and other select indications for breast cancer. However, the interpretation of breast MR images in pregnant and lactating women is complicated by physiologic changes of the breast that may result in marked background enhancement. Breast MRI with contrast administration is contraindicated in pregnancy. Restriction spectrum imaging (RSI) is an advanced diffusion-weighted (DW)-MRI method that theoretically reflects signal from cells with high nuclear-to-cytoplasm ratio without gadolinium-based contrast. This report describes a case in which RSI notably increased tumor conspicuity in a lactating woman, compared to contrast-enhanced (CE)-MRI and conventional DW-MRI