3,322 research outputs found
Aspects of structure and functionality in legumin and vicilin from vicia faba seeds
Get PDFSoy beans command a large proportion of the vegetable protein market of the food processing industry; however, their cultivation is limited by climatic factors. A crop able to compete in these markets, but suited to growth in cooler, temperate conditions would have political and economic advantages for Europe. One such crop under consideration is Vicia faba minor. A new faba bean line (IVS-G),developed by a breeding programme at Durham University, was compared to an established commercial variety (Maris Bead) for chemical, physical and functional characteristics. A selection of processing methods was used to produce proteinaceous materials equivalent to soy products already on the commercial market. The methods used were defatting, air-classification, and the production of isolates, proteinates and micellar protein preparations. The materials were assessed and compared to soy products for functionality in tests designed to assess solubility, gelling, foaming and emulsifying properties. The storage proteins, legumin and vicilin, are the major protein constituents of the bean seed, and their structural and functional properties were also investigated. The bean products had similar functional properties to equivalent soy products, when protein contents were also similar. However, the higher initial in vivo protein content of the soy bean does give the latter a competitive advantage. Also, the marketing of by-products of faba bean, eg. Starch and fibre, may prove difficult
Laboratory assessment of the consumption rate of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on a mung bean (Vigna radiata)-based artificial diet
Get PDFSpodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest in Indonesia. Therefore, limited insect stock is a limiting factor for researchers. The aim of this research rearing insects with mung bean-based as a protein source to modify the composition of the artificial diet. The parameters observed in this research were larva period, larval survival rate, pupal size, sex ratio, pupal-stage longevity, pupal survival rate, fecundity, and nutritional index. The results showed that an artificial diet with mung bean had a significant effect on sex ratio, pupal survival rate, efficiency of conversion of ingestion (ECI) food, efficiency of conversion digested (ECD) food, approximate digestibility (AD) 96,54% 4th instar; 95.45% 5th instar: 88,35% 6th instar, fecundity 307,14 eggs/female, pupal period and significant effect on larval period though instars are longer. Artificial diet-based mung bean had high potential for use in S. frugiperda rearing
An enzymatic mechanism for calcium current inactivation in dialysed Helix neurones
No full text'Wash-out' and inactivation of the Ca current were examined in dialysed, voltage-clamped neurones of Helix aspersa under conditions that isolate the Ca current virtually free of other currents. EGTA or other internal Ca2+ chelators were routinely omitted from the dialysate. The time-dependent loss, or wash-out, of Ca current was slowed by addition to the dialysing solution of agents, such as dibutyryl adenosine 3'-5'-cyclic monophosphate (dibutyryl cyclic AMP), Mg adenosine 5'-triphosphate (ATP) and the catalytic subunit of cyclic-AMP-dependent protein kinase, that promote protein phosphorylation and by EGTA. However, neither the phosphorylation-promoting agents nor internal EGTA prevented wash-out entirely, nor did they significantly restore previously 'washed-out' current. With phosphorylating agents in the dialysing solution, the irreversible development of wash-out was greatly reduced by introduction of leupeptin, an inhibitor of protease activity. Thus, the irreversible component of wash-out appears to result from a Ca-dependent proteolytic process. In the presence of leupeptin alone, Ca current amplitude continued to decline: however, the current could be largely or fully restored with addition of catalytic subunit, dibutyryl cyclic AMP, and Mg ATP to the dialysing solution. Thus, inhibition of proteolysis revealed a reversible component of wash-out that appears to result from dephosphorylation. During perfusion with leupeptin, Mg ATP, dibutyryl cyclic AMP and catalytic subunit the Ca current remained stable for up to several hours without addition of internal Ca2+ buffer. The rate of inactivation of the current that occurs during a depolarizing step showed only a very gradual decline during this time. Under these conditions, perfusion with calcineurin, a Ca-calmodulin-dependent phosphatase, caused a significant increase in the rate of Ca current inactivation. This inactivation was virtually eliminated by introduction of EGTA or by replacement of external Ca2+ with Ba2+, which is consistent with the ion dependency for calmodulin-dependent activation of calcineurin. When ATP in the dialysate was replaced with ATP-gamma-S (adenosine 5'-O-(thiotriphosphate], an analogue that donates a thiophosphate group resistant to hydrolysis, the rate of inactivation slowed. Since Ca-dependent inactivation during step depolarizations is enhanced by conditions that promote dephosphorylation, and Ca current wash-out is slowed by conditions that promote phosphorylation, inactivation and reversible wash-out appear to be related
The effect of 2,4,5-TP on the activity of cellulase, pectin methylesterase and polygalacturonase in bean explants
No full textBean explants were used as a model system to study the effect of 2-(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP) on certain enzymes which are involved in abscission. An increase in cellulase activity in pulvini, petioles and abscission zones during the course of abscission was significantly inhibited by 2,4,5-TP. During abscission the gradient of pectin methylesterase (PME) activity in control explants decreased significantly, but 2,4,5-TP maintained this gradient by increasing PME-activity in abscission zones and maintaining it in pulvini and petioles. The activity of exo-polygalacturonase (exo-PG) was not affected by 2,4,5-TP. However, the activity of endo-PG increased from zero to a maximum in control explants, with 2,4,5-TP maintaining the activity at zero. It is concluded that 2,4,5-TP prevents abscission in bean explants by maintaining a form(s) of pectin constituting a more rigid complex in middle lamellae
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Preliminary Geologic Map of the North Half of the Union Pass Quadrangle, Mohave County, Arizona
No full textPreliminary Geologic Map of the North Half of the Union Pass Quadrangle, Mohave County, Arizona. Includes one map sheet with cross section at 1:24,000 map scale.On 1/17/2014, F.L. Hillemeyer's name was removed from the author list per his request. (The request was forwarded to AZGS by J.E. Faulds.)Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]
Building and Defining Behavioral Economics
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95156.pdf (Publisher’s version ) (Closed access)George Loewenstein, a prominent behavioral economist, recalls thatIn 1994, when Thaler, Camerer, Rabin, Prelec and I spent the year at the Center for Advanced Study in the Behavioral Sciences, we had a meeting to make a kind of final decision about what to call what we were doing. Remarkably, at that time, the name behavioral economics was not yet well established. I actually advocated “psychological economics,” and Thaler was strong on behavioral economics. I'm kind of glad that he prevailed; I think it's a better, catchier, label, although it creates confusion due to association with Behaviorism. (G. Loewenstein, personal email to author, June 16, 2008
The IPHAS catalogue of H alpha emission-line sources in the northern Galactic plane
Get PDFWe present a catalogue of point-source H alpha emission-line objects selected from the INT/WFC Photometric Ha Survey (IPHAS) of the northern Galactic plane. The catalogue covers the magnitude range 13 <= r' <= 19.5 and includes Northern hemisphere sources in the Galactic latitude range -5 degrees < b < 5 degrees. It is derived from similar to 1500 deg(2) worth of imaging data, which represents 80 per cent of the final IPHAS survey area. The electronic version of the catalogue will be updated once the full survey data become available. In total, the present catalogue contains 4853 point sources that exhibit strong photometric evidence for Ha emission. We have so far analysed spectra for similar to 300 of these sources, confirming more than 95 per cent of them as genuine emission-line stars. A wide range of stellar populations are represented in the catalogue, including early-type emission-line stars, active late-type stars, interacting binaries, young stellar objects and compact nebulae.
The spatial distribution of catalogue objects shows overdensities near sites of recent or current star formation, as well as possible evidence for the warp of the Galactic plane. Photometrically, the incidence of Ha emission is bimodally distributed in (r' - i'). The blue peak is made up mostly of early-type emission-line stars, whereas the red peak may signal an increasing contribution from other objects, such as young/active low-mass stars. We have cross-matched our H alpha-excess catalogue against the emission-line star catalogue of Kohoutek & Wehmeyer, as well as against sources in SIMBAD. We find that fewer than 10 per cent of our sources can be matched to known objects of any type. Thus IPHAS is uncovering an order of magnitude more faint (r' > 13) emission-line objects than were previously known in the Milky Way
The effect of 2,4,5-TP and ethylene on the abscission of bean explants
No full textThis study was undertaken in an attempt to show that a favourable gradient of 2-(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP) across abscission zones prevents abscission in bean explants by rendering them insensitive to ethylene. The effect of applied ethylene and an ethylene-free atmosphere on the abscission of explants was studied. It was found that 2,4,5-TP greatly enhanced 14C-ethylene evolution from 14C-methionine by explants and petiole sections and that applied ethylene could not induce abscission in explants treated with 2,4,5-TP. Untreated explants eventually abscised in an ethylene-free atmosphere
Testing protoplanetary disc dispersal with radio emission
No full textWe consider continuum free–free radio emission from the upper atmosphere of protoplanetary discs as a probe of the ionized luminosity impinging upon the disc. Making use of previously computed hydrodynamic models of disc photoevaporation within the framework of extreme-ultraviolet (EUV) and X-ray irradiation, we use radiative transfer post-processing techniques to predict the expected free–free emission from protoplanetary discs. In general, the free–free luminosity scales roughly linearly with ionizing luminosity in both EUV- and X-ray-driven scenarios, where the emission dominates over the dust tail of the disc and is partial optically thin at cm wavelengths. We perform a test observation of GM Aur at 14–18?GHz and detect an excess of radio emission above the dust tail to a very high level of confidence. The observed flux density and spectral index are consistent with free–free emission from the ionized disc in either the EUV- or the X-ray-driven scenario. Finally, we suggest a possible route to testing the EUV- and X-ray-driven dispersal model of protoplanetary discs, by combining observed free–free flux densities with measurements of mass-accretion rates. On the point of disc dispersal one would expect to find an M?2? scaling with free–free flux in the case of EUV-driven disc dispersal or an ?* scaling in the case of X-ray-driven disc dispersa
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