512 research outputs found
Mixed Ancestry and Admixture in Kauai\u27s Feral Chickens: Invasion of Domestic Genes into Ancient Red Junglefowl Reservoirs
A major goal of invasion genetics is to determine how establishment histories shape non‐native organisms\u27 genotypes and phenotypes. While domesticated species commonly escape cultivation to invade feral habitats, few studies have examined how this process shapes feral gene pools and traits. We collected genomic and phenotypic data from feral chickens (Gallus gallus) on the Hawaiian island of Kauai to (i) ascertain their origins and (ii) measure standing variation in feral genomes, morphology and behaviour. Mitochondrial phylogenies (D‐loop & whole Mt genome) revealed two divergent clades within our samples. The rare clade also contains sequences from Red Junglefowl (the domestic chicken\u27s progenitor) and ancient DNA sequences from Kauai that predate European contact. This lineage appears to have been dispersed into the east Pacific by ancient Polynesian colonists. The more prevalent MtDNA clade occurs worldwide and includes domesticated breeds developed recently in Europe that are farmed within Hawaii. We hypothesize this lineage originates from recently feralized livestock and found supporting evidence for increased G. gallus density on Kauai within the last few decades. SNPs obtained from whole‐genome sequencing were consistent with historic admixture between Kauai\u27s divergent (G. gallus) lineages. Additionally, analyses of plumage, skin colour and vocalizations revealed that Kauai birds\u27 behaviours and morphologies overlap with those of domestic chickens and Red Junglefowl, suggesting hybrid origins. Together, our data support the hypotheses that (i) Kauai\u27s feral G. gallus descend from recent invasion(s) of domestic chickens into an ancient Red Junglefowl reservoir and (ii) feral chickens exhibit greater phenotypic diversity than candidate source populations. These findings complicate management objectives for Pacific feral chickens, while highlighting the potential of this and other feral systems for evolutionary studies of invasions
Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles
Background: There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes.
Methods: Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-gamma ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl beta-galactosidase assay with primary isolates of HIV-1.
Results: This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques elicited an HIV-specific antibody response. However, the antibodies did not neutralise primary isolates of HIV-1 or the V3-sensitive isolate SF162 using the TZM-bl b-galactosidase assay.
Conclusions: MVA and FP9 are ideal replication-deficient viral vectors for HIV-1 vaccines due to their excellent safety profile for use in humans. This study shows this novel prime-boost-boost regimen was poorly immunogenic in Chinese cynomolgus macaques
Development of a Robust, High Current, Low Power Field Emission Electron Gun for a Spaceflight Reflectron Time-of-Flight Mass Spectrometer
Carbon materials, including carbon nanotubes (CNTs) and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD), have been of considerable interest for field emission applications for over a decade. In particular, robust field emission materials are compelling for space applications due to the low power consumption and potential for miniaturization. A reflectron time-of-flight mass spectrometer (TOF-MS) under development for in situ measurements on the Moon and other Solar System bodies uses a field emitter to generate ions from gaseous samples, using electron ionization. For these unusual environments, robustness, reliability, and long life are of paramount importance, and to this end, we have explored the field emission properties and lifetime of carbon nanotubes and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) thin films, the latter developed and patented by Argonne National Laboratory. We will present recent investigations of N-UNCD as a robust field emitter, revealing that this material offers stable performance in high vacuum for up to 1000 hours with threshold voltage for emission of about 3-4 V/lJm and current densities in the range of tens of microA. Optimizing the mass resolution and sensitivity of such a mass spectrometer has also been enabled by a parallel effort to scale up a CNT emitter to an array measuring 2 mm x 40 mm. Through simulation and experiment of the new extended format emitter, we have determined that focusing the electron beam is limited due to the angular spread of the emitted electrons. This dispersion effect can be reduced through modification of the electron gun geometry, but this reduces the current reaching the ionization region. By increasing the transmission efficiency of the electron beam to the anode, we have increased the anode current by two orders of magnitude to realize a corresponding enhancement in instrument sensitivity, at a moderate cost to mass resolution. We will report recent experimental and modeling results to describe the performance of a field emission electron gun as employed in the Volatile Analysis by Pyrolysis of Regolith (VAPoR) TOF-MS prototype
In Situ Instrument to Detect Prebiotic Compounds in Planetary Ices
The development of an in situ LC-MS instrument for future planetary science missions to icy surfaces that are of high astrobiology and astrochemistry potential will advance our understanding of organics in the solar system
Understanding the Impact of Field-Emitter Characteristics on Electron Beam Focusing in the VAPoR Time-of-Fight Mass Spectrometer
Simulations of field emission of electrons from an electron gun are used to determine the angular distribution of the emitted electron beam and the percentage of charge transmitted through the grid. The simulations are a first step towards understanding the spherical aberration present after focusing the electron beam. The effect of offset of the cathode with respect to the grid and the separation between cathode and grid on the angular distributions of emitted electrons and transmission of the grid are explored
Whistler mode startup in the Michigan Mirror Machine
Results of investigations of whistler mode ECRH plasma startup in the Michigan Mirror Machine are presented. Electron‐velocity‐distribution and plasma‐spatial‐distribution time evolution are characterized by measurements from axially and radially moveable Langmuir probes, an endloss current detector, an electron cyclotron emission radiometer, a foil‐filtered X‐ray detector, and a diamagnetic loop at the mirror midplane. Measurements of the buildup of both electron density and perpendicular pressure (nkT⟂) are compared to predictions from various numerical models. Both modeling and data suggest the creation of a highly anisotropic electron velocity distribution function with a ‘‘sloshing electron’’ axial density profile.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87352/2/204_1.pd
Osteosarcoma Phenotype Is Inhibited by 3,4-Methylenedioxy-β-nitrostyrene
β-nitrostyrene compounds, such as 3,4-methylenedioxy-β-nitrostyrene (MNS), inhibit growth and induce apoptosis in tumor cells, but no reports have investigated their role in osteosarcoma. In this study, human osteosarcoma cell families with cell lines of varying tumorigenic and metastatic potential were utilized. Scrape motility assays, colony formation assays, and colony survival assays were performed with osteosarcoma cell lines, both in the presence and absence of MNS. Effects of MNS on human osteoblasts and airway epithelial cells were assessed in monolayer cultures. MNS decreased metastatic cell line motility by 72–76% and colony formation by 95–100%. MNS consistently disrupted preformed colonies in a time-dependent and dose-dependent manner. MNS had similar effects on human osteoblasts but little effect on airway epithelial cells. An inactive analog of MNS had no detectable effects, demonstrating specificity. MNS decreases motility and colony formation of osteosarcoma cells and disrupts preformed cell colonies, while producing little effect on pulmonary epithelial cells
Development of a High Protein Dairy Snack Based on German-Style Quark Cheese
Current consumer trends highlight the need for developing convenient and ready-to-eat snack foods that render health benefits when consumed. Rising popularity of protein-enriched foods and beverages have led to increasing awareness among consumers of health benefits related to a dairy-rich diet. The vast majority of people have adopted this lifestyle, spotting the protein’s importance in delivering vital nutrients for health and maintenance of the body, curbing hunger, sustaining a slow release of energy, and speeding the metabolism. Innovation is the key driver for the dairy snack market. The primary objective of this project was to develop an American-sourced predominantly dairy (\u3e51%) snack which meets both the current snacking trends and REAL® Seal requirement. The research also focused on assessing the acceptance of a dairy snack (“Quick-Quark”) formulated with German-style quark cheese. An acceptance test with consumers using a 9-point hedonic and a “just-about-right” scale showed that flavor, mouthfeel, and texture attributes were within the liking rate of consumers. Furthermore, the higher protein content in the Quick-Quark gives this product an added value that may have a great influence on consumers’ preference
Two-step Laser Time-of-Flight Mass Spectrometry to Elucidate Organic Diversity in Planetary Surface Materials.
Laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) holds promise to be a low-mass, compact in situ analytical capability for future landed missions to planetary surfaces. The ability to analyze a solid sample for both mineralogical and preserved organic content with laser ionization could be compelling as part of a scientific mission pay-load that must be prepared for unanticipated discoveries. Targeted missions for this instrument capability include Mars, Europa, Enceladus, and small icy bodies, such as asteroids and comets
Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players
Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL), and higher body fat percentage (29.2±7.9% versus 23.2±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk
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