Modulation of Octopaminergic Signaling on a High Sugar Diet

HonorsUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/162614/1/emdennis.pd

Property rights, collective action, and plant genetic resources

"Many factors affect the conservation of biodiversity, including demographic changes, technological developments, national agricultural policies, and economic, social, and cultural factors. Institutional aspects related to property rights and collective action play a key role in local plant genetic conservation outcomes... Policymakers should be aware of the links between property rights, collective action, and local conservation of local plant genetic diversity. It is important to take into account local regulatory frameworks as well as the existence and overlap of multiple legal systems, try to build on these, and avoid policies that might in fact reduce access to genetic diversity for local populations, in order to avoid eroding genetic diversity and increasing the vulnerability of the poor." from Text.Poverty alleviation ,Property rights ,Collective action ,

Chemical Abundances in Virgo Spiral Galaxies II: Effects of Cluster Environment

We present new measurements of chemical abundances in H II regions in spiral galaxies of the Virgo cluster and a comparison of Virgo galaxies and field spirals. With these new data there now exist nine Virgo spirals with abundance measurements for at least four H II regions. Our sample of Virgo galaxies ranges from H I deficient objects near the core of the cluster to galaxies with normal H I properties, far from the cluster core. We investigate the relationship between H I disk characteristics and chemical abundances to determine whether dynamical process that remove gas from the disk, such as ram pressure stripping by the intracluster medium, also affect the chemical abundances.Comment: 53 pages (gzip'ed and uuencoded postscript) Accepted for publication for the Astrophysical Journa

Durability and Performance Evaluations of SuperHydrophobic and Icephobic Coatings for Tube-Fin Heat Exchangers

Mitigating frost on heat exchanger coils is key for developing high-efficiency heat pumps and enabling the widespread adoption of cold-climate heat pumps. Frost reduces heat exchanger (HX) performance by impeding airflow and adding thermal resistance, therefore taxing the system to consume more energy to satisfy temperature setpoints. Accordingly, heat pump systems have defrost cycles, which typically involve electrical heaters or hot-gas bypass systems, that consume extra energy to melt away the impeding frost/ice layer on coils. As presented in prior literature, enhanced HX surfaces (such as louvered fins or increased fin density) can accelerate frost development and thus have faster performance degradation through increased pressure drop across the coils. Thus, non-enhanced fin surfaces (such as wavy fins) with low fin densities, are typically employed in HVAC systems to minimize frosting impacts, however resulting in less compact units with lower performance under dry conditions. An alternative solution could be the use of durable superhydrophobic/icephobic coatings. This paper presents a systematic approach for testing various coatings for their viability to mitigate frost on Tube-Fin HXs. The tests shown in this paper were used as preliminary screening tests to identify coatings for a more comprehensive frost development assessment. Aluminum fin stock samples were coated by several coating vendors for understanding their hydrophobicity, icephobicity, and durability. This involved (a) an ice adhesion test to measure the maximum amount of shear force required to remove ice from the surface; (b) cyclic corrosion testing (CCT-4 standard) while qualitatively monitoring wear; (c) adhesion testing (ASTM D3359 standard) to further understand the coating-substrate bond strength; and (d) post-corrosion ice adhesion tests to characterize durability and potential performance of coatings over time in real-world environments. While most coatings maintained their wettability state after being placed in the corrosion chamber for over 1000 hours, qualitative wear and performance was shown to vary between different coatings of different chemical compositions. Variances in additives and base chemistries were shown to impact the long-term performance of the coatings. Selected coatings were then identified for a more comprehensive frost development assessment in a temperature and humidity-controlled wind-tunnel

Tbx1 and Brn4 regulate retinoic acid metabolic genes during cochlear morphogenesis

<p>Abstract</p> <p>Background</p> <p>In vertebrates, the inner ear is comprised of the cochlea and vestibular system, which develop from the otic vesicle. This process is regulated via inductive interactions from surrounding tissues. <it>Tbx1</it>, the gene responsible for velo-cardio-facial syndrome/DiGeorge syndrome in humans, is required for ear development in mice. <it>Tbx1 </it>is expressed in the otic epithelium and adjacent periotic mesenchyme (POM), and both of these domains are required for inner ear formation. To study the function of <it>Tbx1 </it>in the POM, we have conditionally inactivated <it>Tbx1 </it>in the mesoderm while keeping expression in the otic vesicle intact.</p> <p>Results</p> <p>Conditional mutants (<it>TCre-KO</it>) displayed malformed inner ears, including a hypoplastic otic vesicle and a severely shortened cochlear duct, indicating that <it>Tbx1 </it>expression in the POM is necessary for proper inner ear formation. Expression of the mesenchyme marker <it>Brn4 </it>was also lost in the <it>TCre-KO</it>. <it>Brn4</it>^-;<it>Tbx1</it>^+/-embryos displayed defects in growth of the distal cochlea. To identify a potential signal from the POM to the otic epithelium, expression of retinoic acid (RA) catabolizing genes was examined in both mutants. <it>Cyp26a1 </it>expression was altered in the <it>TCre-KO</it>, while <it>Cyp26c1 </it>showed reduced expression in both <it>TCre-KO </it>and <it>Brn4</it>^-;<it>Tbx1</it>^+/-embryos.</p> <p>Conclusion</p> <p>These results indicate that <it>Tbx1 </it>expression in the POM regulates cochlear outgrowth potentially via control of local retinoic acid activity.</p

Enseignement de l'échographie au chevet à l'aide d'une technique de visioconférence

Implication Statement Point-of-care ultrasound (POCUS) has usually been taught using a hands-on, in-person approach. We present a novel approach to delivering POCUS virtually using a dual image videoconferencing technique. We outline an easily implementable approach and summarize medical students’ experience and feedback. This form of delivery has potential to improve instructional delivery in resource restricted settings or during pandemic restrictions where a hands-on approach may not be possible.Énoncé des implications de la recherche L'échographie au chevet fait généralement l’objet d’un enseignement pratique, en personne. Nous présentons une nouvelle approche, virtuelle, pour son enseignement, par visioconférence à double flux vidéo. L’approche que nous décrivons est facile à mettre en œuvre. Nous résumons l'expérience et les commentaires des étudiants en médecine sur cette modalité qui est susceptible d'améliorer l'enseignement dans des contextes où les ressources sont limitées ou en cas de pandémie, lorsque l’approche pratique n'est pas possible

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics

SLS Block 1-B and Exploration Upper Stage Navigation System Design

The SLS Block 1B vehicle is planned to extend NASA's heavy lift capability beyond the initial SLS Block 1 vehicle. The most noticeable change for this vehicle from SLS Block 1 is the swapping of the upper stage from the Interim Cryogenic Propulsion stage (ICPS), a modified Delta IV upper stage, to the more capable Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability and execute more demanding missions so must the SLS Integrated Navigation System to support those missions. The SLS Block 1 vehicle carries two independent navigation systems. The responsibility of the two systems is delineated between ascent and upper stage flight. The Block 1 navigation system is responsible for the phase of flight between the launch pad and insertion into Low-Earth Orbit (LEO). The upper stage system assumes the mission from LEO to payload separation. For the Block 1B vehicle, the two functions are combined into a single system intended to navigate from ground to payload insertion. Both are responsible for self-disposal once payload delivery is achieved. The evolution of the navigation hardware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1-B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1-B vehicle navigation system is designed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. This is measured in terms of payload impact and stage disposal requirements. Additionally, the Block 1-B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and Fault Detection, Isolation, and Recovery (FDIR) logic. The preliminary Block 1B integrated navigation system design is presented along with the challenges associated with meeting the design objectives. This paper also addresses the design considerations associated with the use of Block 1 and Commercial Off-the-Shelf (COTS) avionics for Block 1-B/EUS as part of an integrated vehicle suite for orbital operations