2,510 research outputs found

    Protoemics of integral membrane proteins from developing Brassica napus

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    Abstract only availableAs plant seeds develop the accumulation of natural products, starch, oil, and protein undergo dramatic changes. At the early stages of seed filling in oilseeds starch is the principal component. Oil (triacylglycerol) and protein concentrations do not reach a maximum until the later stages of seed development. This metabolic shift within the seed, from production of starch to production of oil and protein, indicates that seed metabolism is regulated temporally. To better understand these metabolic changes it is important to examine the cognate changes in protein expression. Integral membrane proteins represent one class of proteins which are important for inter-organellar metabolic flow. Current two-dimensional electrophoresis techniques are unsuitable for the profiling of hydrophobic membrane proteins. To specifically characterize this class of proteins, a reproducible protocol for membrane protein isolation that can be used with standard sodium dodecyl sulfate polyacrylamide gel electrophoresis needed to be developed. Alkaline sodium carbonate washing of membranes followed by ultracentrifugation appeared to yield washed membrane fractions distinct from total protein fractions. To quantify relative volume and molecular weights of individual bands, Coomassie stained gels were analyzed with ImageQuant software. Identification of these bands was performed by trypsin digesting each protein (in-gel) and obtaining accurate peptide mass 'tags' using Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) mass spectrometry. Peptide mass fingerprinting resulted in twelve conclusive identifications (out of 25 analyzed). Of these, six proteins were involved in the glucosinolate-myrosinase defense pathway. These proteins are suspected to be membrane associated, and are involved in a defense system that protects plant tissues from herbivory and fungal, viral, and bacterial infections. Other proteins were identified as: the RuBisCO large subunit, histone H3, NADH dehydrogenase subunit, pyruvate dehydrogenase E1 alpha subunit, and two types of cruciferins which are seed storage proteins. Of these, only NADH dehydrogenase is an integral membrane protein. Based on this data, the alkaline sodium carbonate wash method did not effectively enrich for integral membrane proteins. This may be due largely to the fact that certain proteins, especially cruciferin seed storage proteins, RuBisCO and myrosinases, are expressed at much higher levels than integral membrane proteins and are not quantitatively removed from membrane fractions by salt washing alone. Future work will include alternative approaches to membrane protein isolation including organic extraction.MU Monsanto Undergraduate Research Fellowshi

    Measurement of CH3_3D on Titan at Submillimeter Wavelengths

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    We present the first radio/submillimeter detection of monodeuterated methane (CH3_3D) in Titan's atmosphere, using archival data from of the Atacama Large Millimeter/submillimeter Array (ALMA). The JK=2111J_K=2_1-1_1 and JK=2010J_K=2_0-1_0 transitions at 465.235 and 465.250 GHz (0.644\sim0.644 mm) were measured at significance levels of 4.6σ4.6\sigma and 5.7σ5.7\sigma, respectively. These two lines were modeled using the Non-linear optimal Estimator for MultivariatE spectral analySIS (NEMESIS) radiative transfer code to determine the disk-averaged CH3_3D volume mixing ratio = 6.157×1066.157\times10^{-6} in Titan's stratosphere (at altitudes >130\gt130 km). By comparison with the CH4_4 vertical abundance profile measured by Cassini-Huygens mass spectrometry, the resulting value for D/H in CH4_4 is (1.033±0.081)×104(1.033\pm0.081)\times10^{-4}. This is consistent with previous ground-based and in-situ measurements from the Cassini-Huygens mission, though slightly lower than the average of the previous values. Additional CH3_3D observations at higher spatial resolution will be required to determine a value truly comparable with the Cassini-Huygens CH4_4 measurements, by measuring CH3_3D with ALMA close to Titan's equator. In the post-Cassini era, spatially resolved observations of CH3_3D with ALMA will enable the latitudinal distribution of methane to be determined, making this an important molecule for further studies.Comment: 9 pages, 4 figure

    Disputed transactions: documents, language and authority in Eighteenth-century Marwar

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    This is the final version. Available on open access from Brill via the DOI in this recordEven though all state documents in Marwar in the second half of the eighteenth century were issued in Rajasthani, Persian-language documents continued to have an active legal life and were debated, discussed and judged through Rajasthani-language petitions and orders. A close reading of one such dispute highlights tensions over the authority of community versus documents, how new forms of state record-keeping affected the legal use of documents, and how the Rajput king’s practice of customary law led to both the interpolation of shariʿa principles into that law when applied to Muslims and to the restriction of the qazi’s jurisdiction.European Research CommissionLawforms projectAmerican Institute of Indian Studie

    Women as a Sign of the New? Appointments to South Africa's Constitutional Court since 1994

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    The aim of the article is to develop our understanding of the role bodies play in processes of institutional change. It does so through developing an approach to the politics of institutional newness that highlights the way in which raced and gendered bodies can become entangled with claims to, or judgements of, “being new.” These questions are explored through South Africa's Constitutional Court, newly established as part of South Africa's transition to democracy in the 1990s and at the center of the broader claims being made about the creation of a new democratic, nonracial, and non-sexist South Africa. Focusing on judicial appointments to the Constitutional Court since 1994, the article draws attention to the ways in which historically excluded bodies, women and black men, have been included into this new space within the judiciary. It is argued that exploring the ways in which institutions lay claim to “being new” through the bodies of historically excluded groups is important for our understanding of the dynamics of institutional change being constituted

    Abundance Measurements of Titan's Stratospheric HCN, HC3_3N, C3_3H4_4, and CH3_3CN from ALMA Observations

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    Previous investigations have employed more than 100 close observations of Titan by the Cassini orbiter to elucidate connections between the production and distribution of Titan's vast, organic-rich chemical inventory and its atmospheric dynamics. However, as Titan transitions into northern summer, the lack of incoming data from the Cassini orbiter presents a potential barrier to the continued study of seasonal changes in Titan's atmosphere. In our previous work (Thelen et al., 2018), we demonstrated that the Atacama Large Millimeter/submillimeter Array (ALMA) is well suited for measurements of Titan's atmosphere in the stratosphere and lower mesosphere (~100-500 km) through the use of spatially resolved (beam sizes <1'') flux calibration observations of Titan. Here, we derive vertical abundance profiles of four of Titan's trace atmospheric species from the same 3 independent spatial regions across Titan's disk during the same epoch (2012 to 2015): HCN, HC3_3N, C3_3H4_4, and CH3_3CN. We find that Titan's minor constituents exhibit large latitudinal variations, with enhanced abundances at high latitudes compared to equatorial measurements; this includes CH3_3CN, which eluded previous detection by Cassini in the stratosphere, and thus spatially resolved abundance measurements were unattainable. Even over the short 3-year period, vertical profiles and integrated emission maps of these molecules allow us to observe temporal changes in Titan's atmospheric circulation during northern spring. Our derived abundance profiles are comparable to contemporary measurements from Cassini infrared observations, and we find additional evidence for subsidence of enriched air onto Titan's south pole during this time period. Continued observations of Titan with ALMA beyond the summer solstice will enable further study of how Titan's atmospheric composition and dynamics respond to seasonal changes.Comment: 15 pages, 16 figures, 2 tables. Accepted for publication in Icarus, September 201

    'She's like a daughter to me': insights into care, work and kinship from rural Russia

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    This article draws on ethnographic research into a state-funded homecare service in rural Russia. The article discusses intersections between care, work and kinship in the relationships between homecare workers and their elderly wards and explores the ways in which references to kinship, as a means of authenticating paid care and explaining its emotional content, reinforce public and private oppositions while doing little to relieve the tensions and conflicts of care work. The discussion brings together detailed empirical insights into local ideologies and practices as a way of generating new theoretical perspectives, which will be of relevance beyond the particular context of study

    The role of auditory cortices in the retrieval of single-trial auditory-visual object memories.

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    Single-trial encounters with multisensory stimuli affect both memory performance and early-latency brain responses to visual stimuli. Whether and how auditory cortices support memory processes based on single-trial multisensory learning is unknown and may differ qualitatively and quantitatively from comparable processes within visual cortices due to purported differences in memory capacities across the senses. We recorded event-related potentials (ERPs) as healthy adults (n = 18) performed a continuous recognition task in the auditory modality, discriminating initial (new) from repeated (old) sounds of environmental objects. Initial presentations were either unisensory or multisensory; the latter entailed synchronous presentation of a semantically congruent or a meaningless image. Repeated presentations were exclusively auditory, thus differing only according to the context in which the sound was initially encountered. Discrimination abilities (indexed by d') were increased for repeated sounds that were initially encountered with a semantically congruent image versus sounds initially encountered with either a meaningless or no image. Analyses of ERPs within an electrical neuroimaging framework revealed that early stages of auditory processing of repeated sounds were affected by prior single-trial multisensory contexts. These effects followed from significantly reduced activity within a distributed network, including the right superior temporal cortex, suggesting an inverse relationship between brain activity and behavioural outcome on this task. The present findings demonstrate how auditory cortices contribute to long-term effects of multisensory experiences on auditory object discrimination. We propose a new framework for the efficacy of multisensory processes to impact both current multisensory stimulus processing and unisensory discrimination abilities later in time

    Deep Depth From Focus

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    Depth from focus (DFF) is one of the classical ill-posed inverse problems in computer vision. Most approaches recover the depth at each pixel based on the focal setting which exhibits maximal sharpness. Yet, it is not obvious how to reliably estimate the sharpness level, particularly in low-textured areas. In this paper, we propose `Deep Depth From Focus (DDFF)' as the first end-to-end learning approach to this problem. One of the main challenges we face is the hunger for data of deep neural networks. In order to obtain a significant amount of focal stacks with corresponding groundtruth depth, we propose to leverage a light-field camera with a co-calibrated RGB-D sensor. This allows us to digitally create focal stacks of varying sizes. Compared to existing benchmarks our dataset is 25 times larger, enabling the use of machine learning for this inverse problem. We compare our results with state-of-the-art DFF methods and we also analyze the effect of several key deep architectural components. These experiments show that our proposed method `DDFFNet' achieves state-of-the-art performance in all scenes, reducing depth error by more than 75% compared to the classical DFF methods.Comment: accepted to Asian Conference on Computer Vision (ACCV) 201

    Excited States in Warm and Hot Dense Matter

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    Accurate modeling of warm and hot dense matter is challenging in part due to the multitude of excited states that must be considered. In thermal density functional theory, these excited states are averaged over to produce a single, averaged, thermal ground state. Here we present a variational framework and model that includes explicit excited states. In this framework an excited state is defined by a set of effective one-electron occupation factors and the corresponding energy is defined by the effective one-body energy with an exchange and correlation term. The variational framework is applied to an atom-in-plasma model (a generalization of the so-called average atom model). Comparisons with a density functional theory based average atom model generally reveal good agreement in the calculated pressure, but the new model also gives access to the excitation energies and charge state distributions
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