Arabidopsis thaliana Myosin XI is Necessary for Cell Fate Determination in Root Epidermis

Root hairs are specialized epidermal cells with important functions, such as absorbing water and nutrients from soil. In Arabidopsis thaliana, root hairs develop in a strict position-dependent mechanism that results in alternating longitudinal hair and non-hair cell files along the surface of the root. This invariant pattern is determined, in large part, by a complex network of transcription factors in the epidermis. However, epidermal cells are also highly plastic and have the ability to promote root hair growth even after the hairless cell fate has been determined by transcriptional control. Recently, it has been observed that the mutants of a specific isoform of class XI myosins, mya1, grow ectopic root hairs in Arabidopsis. Since class XI myosin proteins are actin-based molecular motors that transport intracellular organelles or protein complexes, it is possible that MYA1 also has a role in the trafficking of those transcription factors and their upstream regulators that are involved in cell-type patterning. Here, three promoter-GUS (beta-glucuronidase) constructs were utilized to determine what possible cargo or cargoes MYA1 may carry in this signal-transduction pathway. GL2::GUS expression in the roots of 4- to 6-day-old seedlings was first analyzed to determine any differences in patterning between wild-type and mutant genetic backgrounds. The results suggested that the elimination of MYA1 did not affect the expression patterning of GL2, which is the output of the signaling pathway. MYA1, thus, may not be involved in the transcriptional regulation that determines epidermal cell fate in Arabidopsis. It also suggested that MYA1 may then act on the hormonal or nutrient starvation response in root hair development to override the default cell fates set by the network of transcription factors

Beyond prostate-specific antigen: alternatives for prostate neoplasm screening

Prostate adenocarcinoma (PCa) is one of the most prevalent cancers in the world. Second only to lung cancer, the key to its successful treatment is in its early detection. With the introduction of prostate-specific antigen in the early 1990s, a screening test involving measuring levels of this protein was developed to detect PCa in asymptomatic individuals. This test is also known as the PSA test. PCa-specific mortalities have been in decline since the test's introduction. Despite this decline, recent studies have called the efficacy of the PSA test into question. Two large randomized controlled trials conducted in the US and Europe reveal contradicting results as to PSA's accuracy and usefulness. Concerns of overdiagnosis and overtreatment as the result of using PSA screening has led to many national organizations recommending caution or even recommending against its use. Through a thorough review of a large collection of current PCa literature, this study reviews the flaws of using PSA to screen for PCa and investigates alternative approaches currently being pursued through active research to make PCa early detection more accurate. These approaches include improving the accuracy of the PSA screen using PSA-derived testing methods, using PCa-induced epigenetic modifications as a new target for PCa screening, and using urine biomarkers. All of these methods were compared using area under the curve (AUC) values obtained via receiver operating characteristic analysis. Each method has its own flaws but by comparing each of the different approaches, I was able to conclude that out of the currently available screening methods, screening for Engrailed-2 protein in urine is the most promising screening method with the highest AUC values compared to the other methods. Although this method has been introduced in the UK, it has not been introduced in the US yet. Epigenetic screening methods hold the most promise for accurate PCa screening in the future as it confers the highest accuracy in detecting PCa. However, as it hasn't been shown that epigenetic modifications can be easily obtained in the urine or blood serum for easy and accurate screening, I believe more work has to be done in order for it to be successful in being applied as a screening test. By determining the most promising screening type, we can focus resources and efforts towards finding a way to detect PCa early, allowing for successful treatment

SDO Onboard Ephemeris Generation

The Solar Dynamics Observatory (SDO) spacecraft is a sun-pointing, semi-autonomous satellite that will allow nearly continuous observations of the Sun with a continuous science data downlink. The science requirements for this mission necessitate very strict sun-pointing requirements, as well as continuous ground station connectivity through high gain antennas (HGAs). For SDO s onboard attitude control system to successfully point the satellite at the Sun and the HGAs at the ground stations with the desired accuracy, in addition to the need for accurate sensors it must have good onboard knowledge of the ephemerides of the Sun, the spacecraft, and the ground station. This paper describes the minimum force models necessary for onboard ephemeris generation in support of an attitude control system. The forces that were considered include the Sun s point mass, Moon s point mass, solar radiation pressure (SRP), and the Earth s gravity with varying degree and order of terms of the geopotential

Implementing the “Enhancing Music Addressability” API for MusicXML

The ability to “address” areas of a musical score is useful in music scholarship such as analysis and/or historical research.In this project, we implement software that enables us to “select” regions of MusicXML files, in accordance with the Enhancing Music Addressability (EMA) specification