36 research outputs found
Nancy Grace Roman Space Telescope Coronagraph Instrument Observation Calibration Plan
NASA's next flagship mission, the Nancy Grace Roman Space Telescope, is a
2.4-meter observatory set to launch no later than May 2027. Roman features two
instruments: the Wide Field Imager and the Coronagraph Instrument. Roman's
Coronagraph is a Technology Demonstration that will push the current
capabilities of direct imaging to smaller contrast ratios (10) and
inner-working angles (3~/D). In order to achieve this high precision,
Roman Coronagraph data must be calibrated to remove as many potential sources
of error as possible. Here we present a detailed overview of the Nancy Grace
Roman Space Telescope Coronagraph Instrument Observation Calibration Plan
including identifying potential sources of error and how they will be mitigated
via on-sky calibrations.Comment: Posting for public information on the current status of the Roman
Coronagraph Observation Calibration Plan; latest updates as of July 29, 202
The Acute Phase Protein Ceruloplasmin as a Non-Invasive Marker of Pseudopregnancy, Pregnancy, and Pregnancy Loss in the Giant Panda
After ovulation, non-pregnant female giant pandas experience pseudopregnancy. During pseudopregnancy, non-pregnant females exhibit physiological and behavioral changes similar to pregnancy. Monitoring hormonal patterns that are usually different in pregnant mammals are not effective at determining pregnancy status in many animals that undergo pseudopregnancy, including the giant panda. Therefore, a physiological test to distinguish between pregnancy and pseudopregnancy in pandas has eluded scientists for decades. We examined other potential markers of pregnancy and found that activity of the acute phase protein ceruloplasmin increases in urine of giant pandas in response to pregnancy. Results indicate that in term pregnancies, levels of active urinary ceruloplasmin were elevated the first week of pregnancy and remain elevated until 20–24 days prior to parturition, while no increase was observed during the luteal phase in known pseudopregnancies. Active ceruloplasmin also increased during ultrasound-confirmed lost pregnancies; however, the pattern was different compared to term pregnancies, particularly during the late luteal phase. In four out of the five additional reproductive cycles included in the current study where females were bred but no birth occurred, active ceruloplasmin in urine increased during the luteal phase. Similar to the known lost pregnancies, the temporal pattern of change in urinary ceruloplasmin during the luteal phase deviated from the term pregnancies suggesting that these cycles may have also been lost pregnancies. Among giant pandas in captivity, it has been presumed that there is a high rate of pregnancy loss and our results are the first to provide evidence supporting this notion
Feeding Induced by Cannabinoids Is Mediated Independently of the Melanocortin System
Cannabinoids, the active components of marijuana, stimulate appetite, and cannabinoid receptor-1 (CB1-R)
antagonists suppress appetite and promote weight loss. Little is known about how CB1-R antagonists affect the central
neurocircuitry, specifically the melanocortin system that regulates energy balance
Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.
Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists
Effect of Increased 25(OH)D on Bone Health, a High Resolution Peripheral Computed Tomography Study
Vitamin D is important for normal bone health, however, there is still debate over the intake for optimal bone health. The objective of this study is to assess the relationship between large changes in 25(OH)D to bone health, and the safety of taking up to 10,000 IU/day of vitamin D over one-year using a pilot cohort of a three-year ongoing randomized control trial. The results suggest that with increased 25(OH)D there was an improvement in trabecular and cortical BMD, as well as a decrease in cortical area and thickness, while maintaining bone strength. Based on biomarker data, taking doses of vitamin D up to 10,000 IU/day for one year was found to be safe within the population studied. This study has provided new insight into the understanding of large changes in 25(OH)D on bone health and demonstrates the importance of 25(OH)D for maintaining bone health in a healthy adult population
A Fer Kinase Homologue is Expressed during Zebrafish Development
Fer kinase, a non-receptor tyrosine kinase normally involved in the regulation of cell-cell adhesion and proliferation, has also been implicated in both prostate and liver cancer metastasis. However, the function of Fer in both development and cancer formation has yet to be fully characterized. Due to the complexities of functional redundancy with other kinases, it has been difficult to study Fer in other vertebrate model organisms, but the zebrafish (Danio rerio) lacks the redundancy of more complex vertebrates, thus allowing for a higher likelihood of elucidating the in vivo function of Fer. Through mining the zebrafish genome database we have identified a single predicted zebrafish Fer homologue. Our phylogenetic analysis shows that the zebrafish Fer homologue is a descendant of the C. elegans FRK-1 protein and an ancestor to the human Fer kinase. We aim to bridge the gap between the invertebrate and vertebrate realms by characterizing the function of the Fer homologue in zebrafish. Initially, we will show the gene expression profile of the Fer homologue during different stages of development via in situ hybridization analysis. Furthermore, using a cross-reactive antibody to human Fer, we have determined by Western blot analysis that Fer protein is indeed expressed during zebrafish development and are now characterizing the requirement of the protein by using morpholino knockdown technology. Processes that can go awry during development are often similar to the cellular mechanisms that result in cancer. By uncovering the developmental requirements for the Fer homologue in zebrafish we ultimately hope to establish a model in which to study more about cancer mechanisms and ways in which to inhibit tumor growth
Fer Kinase is Required for Hematopoietic Development in Zebrafish
Fer kinase, a protein involved in the regulation of cell-cell adhesion and proliferation, has been implicated in leukemia, gastric cancer, and liver cancer. However, the role Fer plays in the molecular mechanisms of these diseases is largely unknown. By studying the role that Fer plays during development, we hope to obtain a better understanding of its involvement in carcinogenesis. Our lab has shown that FRK-1, a Fer kinase homologue in C. elegans, is involved in stem cell regulation. In this project, we begin to bridge the gap between the invertebrate and vertebrate realms by elucidating the role that Fer kinase plays in zebrafish embryogenesis. Our data indicate that not only is a Fer homologue expressed during zebrafish embryogenesis, but that it is also required for normal hematopoiesis. These results have led us to hypothesize a novel role for Fer as a regulator of either definitive hematopoiesis or the Runx1 pathway
Spreading of α-synuclein in the face of axonal transport deficits in Parkinson's disease: A speculative synthesis.
Parkinson's disease (PD) is mainly attributed to degeneration of dopamine neurons in the substantia nigra, but its etiopathogenesis also includes impaired protein clearance and axonal transport dysfunction, among others. The spread of α-synuclein (α-syn) aggregates from one neuron to another, in a prion-like manner, is hypothesized to contribute to PD progression. Axonal transport is likely to play a crucial role in this movement of α-syn aggregates between brain regions. At the same time, deficits in axonal transport are suggested to contribute to neuronal failure in PD. In this review, we discuss the apparent contradiction that axonal transport might be essential for disease progression, while dysfunction of axonal transport could simultaneously be a cornerstone of PD pathogenesis. We speculate around models that reconcile how axonal transport can play such a paradoxical role
Neural Correlates of Implicit and Explicit Metaphors: An ERP Study
Due to the often unfamiliar nature of metaphors as well as the greater semantic distance between the two concepts being linked, many have hypothesized that figurative language is processed in the right hemisphere (RH) (Jung-Beeman, 2005; Schmidtet al., 2007). However, there have been many contradictory findings in this regard. One factor not previously considered is the existence of different type of metaphors such as implicit metaphors (IM) and explicit metaphors (EM). Our goal was to examine how EM (The veteran professor was a fossil) differ from IM (The teenagers could not relate to the fossil) in their neural processing. Understanding the implicit meaning of a sentence may draw on additional cognitive resources, thereby affecting the difficulty, and perhaps neural pathways involved in processing these sentences. We also wanted determine if the RH is specialized for metaphor processing. We used event-related potentials (ERP) in conjunction with divided visual field presentation to measure the N400 for each sentence as presented to each hemisphere of the brain. ERPs are derived from electroencephalographic (EEG) recordings from the scalp. The N400 is a peak of negative brain activity occurring approximately 400ms after a word, which indexes the ease of semantic processing. We can measure differences in neural processing by observing differences in N400 amplitude across visual field presentation. We conducted an ANOVA with factors of figurativeness, implicitness, and side of presentation using the N400 amplitude as the dependent measure. When IM were presented to the RH, the N400s measured by the parietal lobe electrodes were about the same as those for EM. The left hemisphere (LH) presentation showed much larger N400s for IM than for EM. This suggests that the LH is less efficient at processing IM in comparison to EM while the RH can do both equally well