The Effects of Heterogeneities and Syn-deformational Partial Melting on Rock Strength Evolution and Melt Migration

In nature, the segregation of granitic melts at the source may be controlled by fabric and compositional heterogeneities in the source rock, such as foliation and lineation. To investigate the influence of foliation/lineation orientation and composition on rock strength and melt interconnectivity, I performed a series of experiments on cores of a fine-grained gneiss (Gneiss Minuti) and a fine-grained muscovite-bearing quartzite (Moine Thrust quartzite). These rocks were cored at six primary orientations parallel, 45 degrees, and perpendicular to the foliation and lineation and were deformed at a constant temperature of 900°C, pressure of ~2 GPa, and strain rate of ~10-6/s using the D-DIA apparatus at Beamline 6-BMB at the Advanced Photon Source at Argonne National Laboratory. Strengths of the Gneiss Minuti cores varied from 1.02 to 1.17 GPa, and strengths of the Moine Thrust quartzite ranged from 1.28 to 1.61 GPa. The strength anisotropy of the cores relative to the core with the foliation oriented 45 degrees to the compression direction varied from 0.87 to 1.99 in the Gneiss Minuti cores and ranged from 0.59 to 2.13 in the Moine Thrust quartzite cores. Melt was present in all cores, and concentrations varied from 1 to 4 vol% for the Gneiss Minuti and from 0.6 to 1.2 vol% for the Moine Thrust quartzite. The Gneiss Minuti and Moine Thrust quartzite cores had similar melt topology in all foliation orientations with small melt channels/pockets parallel to the compression direction, and the only significant melt interconnectivity was observed in the Gneiss Minuti foliation/lineation parallel to the compression direction sample, which also had the largest melt fraction (3.74 vol%). These results indicate that when above a low melt content (~1 to 2 vol%), the presence of melt has a greater effect than the orientation of foliation and lineation on the strength of foliated rocks and melt migration

Evaluating Subunit Interfacial Interactions and Chloride Adduction Induced Gas-Phase Stabilization of Diubiquitin using ESI-IM-MS and Collisional Activation Methods

Native electrospray ionization ion mobility mass spectrometry (ESI-IM-MS) allows for the investigation of complex heterogeneous mixtures of intact biomolecules according to their mass, charge, and size, which can provide unique insight into higher order protein structure (i.e. tertiary, quaternary, etc.), solution-phase perturbations, and dynamics. However, this method is more of a “coarse-grained” approach providing relative size information rather than more detailed characterization of local structures. Here we demonstrate the use of the complementary technique collision induced unfolding (CIU) for the characterization of noncovalent intra/intermolecular interactions of the model protein ubiquitin (Ubq), its bioactive oligomers, and the effect of chloride adduction on conformational preference. Ubq is a relatively small protein that participates in a wide-array of bioactivities as defined by the ability to form a variety of oligomeric states. A key facet to the quaternary structure and thus function of Ubq oligomers is the site of covalent-linkage between the subunits. Here we present the investigation of the recently reported non-covalent homodimer of Ubq (ncUbq) and four diubiquitin (diUbq) molecules covalently-linked through different lysine side-chains. Despite that each covalent-linkage site induces distinct conformational preferences owing to steric hindrance induced by the covalent tether, ESI-IM-MS lacks sufficient resolution to differentiate these conformers; however, the CIU fingerprints of each are distinctly different. Furthermore, the CIU fingerprint of ncUbq suggests a high degree of conformational similarity to diUbq covalently linked through K48. ESI-IM-MS is an inherently gas-phase technique, raising the question: How much does the solvent-free ion resemble the solution-phase structure of the analyte, and under what conditions might this structure be preserved? Here, using ESI-IM-MS and CIU, we provide evidence that chloride adduction to Ubq results in gas-phase stabilization of a more compact conformer; furthermore, the more compact conformers of chloride adducted K48-linked diUbq ions demonstrate gas-phase unfolding patterns characteristic of the “native-like” structure reported in the previous sections. Thus we present evidence that chloride adduction to Ubq and K48-linked diUbq ions results in the gas-phase stabilization of the “native-like” conformation of the analyte ion and inducing additional resistance to gas-phase unfolding

Obstacles to the diffusion of adaptation in the Rhein-Neckar region in Germany

Because the impacts of climate change are felt at the local level, we assess adaptation diffusion mechanisms (i.e., learning, competition, and emulation) among smaller big cities and medium-sized towns. Since the diffusion of adaptation has immediate spatial implications, we argue that local conditions play an important role in the diffusion process. The densely populated Rhein-Neckar Metropolitan Region in Germany is an ideal case for studying diffusion mechanisms with regard to adaptation. Using a rich data set of 28 interviews, we unpack the views of local actors such as mayors, city council politicians, city administration representatives, and representatives from regional agencies and identify factors influencing the diffusion of adaptation. We find limited or compromised diffusion due to insufficient knowledge about adaptation, competition between municipalities, and cooperation with cities outside the region. In addition, we find some (albeit limited) political will for adaptation. While some of the interviewed politicians considered making long-term investments in adaptation, most highlighted competing local issues and viewed adaptation with caution, illustrating adaptation’s lack of salience and social legitimacy. Indeed, one crucial finding was that housing and mobility are more important to a wide range of politicians and bureaucrats alike. By examining diffusion mechanisms at the subnational level, we combine theoretical perspectives from political science and geography to show how local decision-makers—in particular, politicians—influence the diffusion mechanisms of adaptation

Distant horizontal gene transfer is rare for multiple families of prokaryotic insertion sequences

Horizontal gene transfer in prokaryotes is rampant on short and intermediate evolutionary time scales. It poses a fundamental problem to our ability to reconstruct the evolutionary tree of life. Is it also frequent over long evolutionary distances? To address this question, we analyzed the evolution of 2,091 insertion sequences from all 20 major families in 438 completely sequenced prokaryotic genomes. Specifically, we mapped insertion sequence occurrence on a 16S rDNA tree of the genomes we analyzed, and we also constructed phylogenetic trees of the insertion sequence transposase coding sequences. We found only 30 cases of likely horizontal transfer among distantly related prokaryotic clades. Most of these horizontal transfer events are ancient. Only seven events are recent. Almost all of these transfer events occur between pairs of human pathogens or commensals. If true also for other, non-mobile DNA, the rarity of distant horizontal transfer increases the odds of reliable phylogenetic inference from sequence dat

Evolutionary dynamics of the LTR retrotransposons roo and rooA inferred from twelve complete Drosophila genomes

BACKGROUND: Roo is the most abundant retrotransposon in the fruit fly Drosophila melanogaster. Its evolutionary origins and dynamics are thus of special interest for understanding the evolutionary history of Drosophila genome organization. We here study the phylogenetic distribution and evolution of roo, and its highly diverged relative rooA in 12 completely sequenced genomes of the genus Drosophila. RESULTS: We identify a total of 164 roo copies, 57 of which were previously unidentified copies that occur in 9 of the 12 genomes. Additionally we find 66 rooA copies in four genomes and remnants of this element in two additional genomes. We further increased the number of elements by searching for individual roo/rooA sequence domains. Most of our roo and rooA elements have been recently inserted. Most elements within a genome are highly similar. A comparison of the phylogenetic tree of our roo and rooA elements shows that the split between roo and rooA took place early in Drosophila evolution. Furthermore there is one incongruency between the species tree and the phylogenetic tree of the roo element. This incongruency regards the placement of elements from D. mojavensis, which are more closely related to D. melanogaster than elements from D. willistoni. CONCLUSION: Within genomes, the evolutionary dynamics of roo and rooA range from recent transpositional activity to slow decay and extinction. Among genomes, the balance of phylogenetic evidence, sequence divergence distribution, and the occurrence of solo-LTR elements suggests an origin of roo/rooA within the Drosophila clade. We discuss the possibility of a horizontal gene transfer of roo within this clade

Effectiveness of mycorrhizae and vermicompost seed inoculation for germination, vegetative growth, cannabinoid content, and cured flower weight of CBD-rich hemp (Cannabis sativa L.)

Effective germination and vigorous growth of hemp cultivars is paramount to cultivators’ ability to produce high-quality hemp products. Beneficial bacteria and fungi are known symbionts to plants and are used in regenerative agriculture to increase plant health and crop yield. This pilot study investigated the effect of microbial seed inoculation on germination rate, plant height, cured flower weight, and cannabinoid content of cannabidiol (CBD)-rich hemp (Cannabis sativa L). The experiment included a control and the following treatments: 1) seed inoculation of Great White â Premium Mycorrhizae (GW), 2) seed inoculation of vermicompost (V), and 3) seed inoculation of Great White â Premium Mycorrhizae and vermicompost (GW+V). There were no significant differences for germination rate or plant height across treatments. For cured flower weight, the GW+V and V groups had increased cured flower weight by 29.0% and 43.0%, respectively, while the GW treatment had 4.4% more weight than the control group. Preliminary results indicate that the GW+V and V treatments had higher total tetrahydrocannabinol (THC) and CBD content than the control at 17.6% and 19.0%, and 17.6% and 12.1%, respectively. These results suggest further investigation is needed to determine if seed inoculation is advantageous for hemp cultivators

Understanding Web Site Satisfaction for Older Adults

As older adults increasingly make use of the Internet, the study of web site usability for older adults is becoming increasingly relevant. Web site usability is concerned with both utilitarian (i.e. functional) and hedonic (i.e. pleasure-related) aspects. This study explores the impact of age on select utilitarian (mental model accuracy and performance) and hedonic (disorientation and engagement) measures of web site usability, and the subsequent impact of these utilitarian and hedonic measures on user satisfaction. An experiment was conducted with 50 younger and 47 older participants. The results suggest that age has a more pronounced impact on utilitarian constructs than hedonic ones. Specifically, older adults were less able to create an accurate mental model of the web site and in turn had poorer performance within the web site. In terms of impact on user satisfaction, the contribution of hedonic constructs was significant while the impact of utilitarian constructs was not