Molecular Padlock Assay of Crude Plant Leaf Extracts for Detection of Listeria Monocytogenes

A molecular padlock assay was developed and assessed for detection of Listeria monocytogenes that operated in crude plant extracts. The molecular padlock assay was developed by Liu et al. (1996) and modified by Lizardi et al. (1998). We further modified and described a padlock probe that detected L. monocytogenes oligonucleotide, cDNA and genomic DNA containing a 16s rRNA sequence (GenBank Acc. No. X56 153). This technique was effective in the presence of crude potato leaf extracts in contrast to PCR, which failed to detect the presence of L. monocytogenes targets in crude leaf extracts. Sensitivity of the padlock procedure was determined to be 0.02 ng using L. monocytogenes genomic DNA target templates and 0.0025 nM L. monocytogenes 40 nt oligonucleotide target sequences in an aqueous solution. Results also showed the efficacy of molecular padlocks to detect L. monocytogenes pathogens in a 5 pg potato leaf RNA background and crude leaf extracts, although sensitivity of the assay is insufficient to dispense with a pre-enrichment step for reliable detection of L. monocytogenes. The advantage of the molecular padlock assay over other FDA approved serological and molecular-based assays, is that it may be possible to design the assay to be species or strain specific while still retaining the ability to be performed in crude plant extracts

Buying of farms in Story County, Iowa, 1940-48

Study of the activities of buyers shows what took place in Story County between 1940 and 1948. Though land purchase did not give rise to serious difficulties during this period of favorable farm incomes, the evaluation of land presents significant problems now and for the future. The years following the land inflation of World War I give evidence that serious difficulties can arise when farm land prices and land income are significantly out of line, and when heavy debts press against low incomes. This study has dealt primarily with the buyer\u27s side of the land market, with particular attention to analysis of procedures followed by buyers in purchasing land. Within this framework there is need for additional information and further analysis. More needs to be known, for example, about how buyers formulate their estimates of the future; about the kinds of data that are used in making important decisions; about the bases for investing in land rather than in some other business. There is also need for analysis of the sellers\u27 side of the market. Among other pertinent questions-upon what bases do sellers decide to sell? How is the asking price determined

How Much for More Land?

Here\u27s a method you can use to estimate the value of adding acreage to your farm. Starting with data from your farm account records, an 8-step procedure indicates about how much you can afford to pay for more land

The Interaction Of Multiple Convection Zones In A-type Stars

A-type stars have a complex internal structure with the possibility of multiple convection zones. If not sufficiently separated, such zones will interact through the convectively stable regions that lie between them. It is therefore of interest to ask whether the typical conditions that exist within such stars are such that these convections zones can ever be considered as disjoint. In this paper we present results from numerical simulations that help in understanding how increasing the distance between the convectively unstable regions are likely to interact through the stable region that separates them. This has profound implications for mixing and transport within these stars.Comment: 9 pages, 15 figures, Preprint accepted for publication in MNRA

Heliophysics Event Knowledgebase for the Solar Dynamics Observatory and Beyond

The immense volume of data generated by the suite of instruments on SDO requires new tools for efficient identifying and accessing data that is most relevant to research investigations. We have developed the Heliophysics Events Knowledgebase (HEK) to fill this need. The HEK system combines automated data mining using feature-detection methods and high-performance visualization systems for data markup. In addition, web services and clients are provided for searching the resulting metadata, reviewing results, and efficiently accessing the data. We review these components and present examples of their use with SDO data.Comment: 17 pages, 4 figure

Enhanced Approaches for Identifying Amadori Products: Application to Peanut Allergens

The dry roasting of peanuts is suggested to influence allergic sensitization as a result of the formation of advanced glycation end products (AGEs) on peanut proteins. Identifying AGEs is technically challenging. The AGEs of a peanut allergen were probed with nano-scale liquid chromatography−electrospray ionization−mass spectrometry (nanoLC−ESI−MS) and tandem mass spectrometry (MS/MS) analyses. Amadori product ions matched to expected peptides and yielded fragments that included a loss of three waters and HCHO. As a result of the paucity of b and y ions in the MS/MS spectrum, standard search algorithms do not perform well. Reactions with isotopically labeled sugars confirmed that the peptides contained Amadori products. An algorithm was developed on the basis of information content (Shannon entropy) and the loss of water and HCHO. Results with test data show that the algorithm finds the correct spectra with high precision, reducing the time needed to manually inspect data. Computational and technical improvements allowed for better identification of the chemical differences between modified and unmodified proteins

An Interface Region Imaging Spectrograph first view on Solar Spicules

Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere remains unknown. Here we give a first glimpse of what quiet Sun spicules look like when observed with NASA's recently launched Interface Region Imaging Spectrograph (IRIS). Using IRIS spectra and filtergrams that sample the chromosphere and transition region we compare the properties and evolution of spicules as observed in a coordinated campaign with Hinode and the Atmospheric Imaging Assembly. Our IRIS observations allow us to follow the thermal evolution of type II spicules and finally confirm that the fading of Ca II H spicules appears to be caused by rapid heating to higher temperatures. The IRIS spicules do not fade but continue evolving, reaching higher and falling back down after 500-800 s. Ca II H type II spicules are thus the initial stages of violent and hotter events that mostly remain invisible in Ca II H filtergrams. These events have very different properties from type I spicules, which show lower velocities and no fading from chromospheric passbands. The IRIS spectra of spicules show the same signature as their proposed disk counterparts, reinforcing earlier work. Spectroheliograms from spectral rasters also confirm that quiet Sun spicules originate in bushes from the magnetic network. Our results suggest that type II spicules are indeed the site of vigorous heating (to at least transition region temperatures) along extensive parts of the upward moving spicular plasma.Comment: 6 pages, 4 figures, accepted for publication in ApJ Letters. For associated movies, see http://folk.uio.no/tiago/iris_spic

Structural Biology of Peanut Allergens

Peanuts are a cause of one of the most common food allergies. Allergy to peanuts not only affects a significant fraction of the population, but it is relatively often associated with strong reactions in sensitized individuals. Peanut and tree nut allergies, which start in childhood are often persistent and continue through life, as opposed to other food allergies that resolve with age. Cherefore, peanut allergens are one of the most intensively studied food allergens. In this review we focus on the structural studies of peanut allergens. Despite the fact that these allergens are attracting a lot of interest and several of them have had their structures experimentally determined, still some molecular properties of peanut allergens are not well understood. Peanut allergens like other allergens belong to just a few protein families. Allergens from the cupin superfamily (Ara h 1 and Ara h 3), 2S albumins (Arah 2 and Ara h 6), Ara h 8 (pathogenesis related class-10 protein) and Ara h 5 (profilin) are relatively well characterized in terms of their 3D structures. However some peanut allergens like Ara h 7 (2S albumin), Ara h 9 (nonspecific lipid-transfer protein), and especially oleosins (Ara h 10 and Ara h 11) and defensins (Ara h 12 and Ara h 13), still are waiting for such characterization

Detection of supersonic downflows and associated heating events in the transition region above sunspots

IRIS data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0.33 arcsec. On 2013 August 30, we observed bursts of high Doppler shifts suggesting strong supersonic downflows of up to 200 km/s and weaker, slightly slower upflows in the spectral lines Mg II h and k, C II 1336 \AA, Si IV 1394 \AA, and 1403 \AA, that are correlated with brightenings in the slitjaw images (SJIs). The bursty behavior lasts throughout the 2 hr observation, with average burst durations of about 20 s. The locations of these short-lived events appear to be the umbral and penumbral footpoints of EUV loops. Fast apparent downflows are observed along these loops in the SJIs and in AIA, suggesting that the loops are thermally unstable. We interpret the observations as cool material falling from coronal heights, and especially coronal rain produced along the thermally unstable loops, which leads to an increase of intensity at the loop footpoints, probably indicating an increase of density and temperature in the TR. The rain speeds are on the higher end of previously reported speeds for this phenomenon, and possibly higher than the free-fall velocity along the loops. On other observing days, similar bright dots are sometimes aligned into ribbons, resembling small flare ribbons. These observations provide a first insight into small-scale heating events in sunspots in the TR.Comment: accepted by ApJ