3,788 research outputs found

    Rapid isolation and characterization of soybean group IX ERF promoters using two different validation tools

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    Promoters are DNA sequences located upstream of gene coding regions that play enormous role in controlling gene expression. Promoters are also important in transgenic crops as they contain the main elements that directly regulate the introduced transgene. Because of their importance, large efforts in our laboratory have recently focused on identification and characterization of plant promoters. Promoters are usually characterized in stably-transformed plants, which take some time to generate. The main goal of this study was to isolate and characterize a soybean ERF group IX promoter family using two new gene expression validation tools. Ten GmERF (Glycine max Ethylene Response Factor) promoters were identified, cloned and initially characterized using quantitative analysis of transient GFP expression in bombarded lima bean cotyledons. Some of the GmERF promoters gave high levels of transient GFP expression, while profiles of transient GFP expression over varies among GmERF promoters. Generation of stably-transformed soybean hairy roots was also evaluated as an additional validation tool for analysis of the GmERF promoter family. Soybean cotyledon explants, inoculated with Agrobacterium rhizogenes, exhibited numerous GFP-positive hairy roots 14-20 days after inoculation. GFP detection in these roots was greatly facilitated by the lack of chlorophyll, which could otherwise interfere with GFP detection. GFP expression intensity was somewhat variable between different events but consistent within events. In summary, 10 different soybean GmERF promoters were isolated and partially characterized in both transiently expressing and stably-transformed tissues.OARDC/The Ohio State UniversityUnited Soybean Boar

    Price Strategy, Market Orientation, and Business Performance in the Hotel Industry

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    This study seeks to study the relationship between market orientation and business performance and to evaluate the mediating effect of adopting a low-price strategy in this relationship in the hotel industry. A sample from the Spanish and Portuguese hotel industry is used. Results show that the effect of market orientation on business performance is positive and direct. On the other hand, the results do not confirm the mediating effect of a strategy based on low-price in the strength of this relationship. Moreover, results indicate that a price strategy based on low-price is negatively related to hotel business performance.info:eu-repo/semantics/publishedVersio

    Tomography of the Reionization Epoch with Multifrequency CMB Observations

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    We study the constraints that future multifrequency Cosmic Microwave Background (CMB) experiments will be able to set on the metal enrichment history of the Inter Galactic Medium at the epoch of reionisation. We forecast the signal to noise ratio for the detection of the signal introduced in the CMB by resonant scattering off metals at the end of the Dark Ages. We take into account systematics associated to inter-channel calibration, PSF reconstruction errors and innacurate foreground removal. We develop an algorithm to optimally extract the signal generated by metals during reionisation and to remove accurately the contamination due to the thermal Sunyaev-Zel'dovich effect. Although demanding levels of foreground characterisation and control of systematics are required, they are very distinct from those encountered in HI-21cm studies and CMB polarization, and this fact encourages the study of resonant scattering off metals as an alternative way of conducting tomography of the reionisation epoch. An ACT-like experiment with optimistic assumtions on systematic effects, and looking at clean regions of the sky, can detect changes of 3%-12% (95% c.l.) of the OIII abundance (with respect its solar value) in the redshift range zz\in [12,22], for reionization redshift zre>10z_{\rm re}>10. However, for zre<10z_{\rm re} <10, it can only set upper limits on NII abundance increments of \sim 60% its solar value in the redshift range zz\in [5.5,9], (95% c.l.). These constraints assume that inter-channel calibration is accurate down to one part in 10410^{4}, which constitutes the most critical technical requirement of this method, but still achievable with current technology.Comment: 10 pages, 2 figures, submitted to Astrophysical Journal. Comments are welcom

    Understanding the Origins of a Pandemic Virus

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    Understanding the pre-pandemic conditions and the origin of infectious diseases provides scientifically based rationales for implementing public health measures that help to avoid, or at least to mitigate, future epidemics. The recent ancestors of a pandemic virus provide an invaluable information about the set of minimal genomic alterations that transformed a zoonotic agent into a full human pandemic. Since the first confirmed cases of the H1N1pdm virus in the spring of 2009 several hypotheses about the strain's origins have been proposed. However, how, where, and when it first infected humans is still far from clear. The only way to piece together such an epidemiological puzzle relies on the collective effort of the international scientific community to increase genomic sequencing of influenza isolates, especially ones collected in the months prior to the origin of the pandemic

    Robotics and Dynamic Image Analysis for Studies of Gene Expression in Plant Tissues

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    Gene expression in plant tissues is typically studied by destructive extraction of compounds from plant tissues for in vitro analyses. The methods presented here utilize the green fluorescent protein (gfp) gene for continual monitoring of gene expression in the same pieces of tissues, over time. The gfp gene was placed under regulatory control of different promoters and introduced into lima bean cotyledonary tissues via particle bombardment. Cotyledons were then placed on a robotic image collection system, which consisted of a fluorescence dissecting microscope with a digital camera and a 2-dimensional robotics platform custom-designed to allow secure attachment of culture dishes. Images were collected from cotyledonary tissues every hour for 100 hours to generate expression profiles for each promoter. Each collected series of 100 images was first subjected to manual image alignment using ImageReady to make certain that GFP-expressing foci were consistently retained within selected fields of analysis. Specific regions of the series measuring 300 x 400 pixels, were then selected for further analysis to provide GFP Intensity measurements using ImageJ software. Batch images were separated into the red, green and blue channels and GFP-expressing areas were identified using the threshold feature of ImageJ. After subtracting the background fluorescence (subtraction of gray values of non-expressing pixels from every pixel) in the respective red and green channels, GFP intensity was calculated by multiplying the mean grayscale value per pixel by the total number of GFP-expressing pixels in each channel, and then adding those values for both the red and green channels. GFP Intensity values were collected for all 100 time points to yield expression profiles. Variations in GFP expression profiles resulted from differences in factors such as promoter strength, presence of a silencing suppressor, or nature of the promoter. In addition to quantification of GFP intensity, the image series were also used to generate time-lapse animations using ImageReady. Time-lapse animations revealed that the clear majority of cells displayed a relatively rapid increase in GFP expression, followed by a slow decline. Some cells occasionally displayed a sudden loss of fluorescence, which may be associated with rapid cell death. Apparent transport of GFP across the membrane and cell wall to adjacent cells was also observed. Time lapse animations provided additional information that could not otherwise be obtained using GFP Intensity profiles or single time point image collections

    A Multiple System of Radio Sources at the Core of the L723 Multipolar Outflow

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    We present high angular resolution Very Large Array multi-epoch continuum observations at 3.6 cm and 7 mm towards the core of the L723 multipolar outflow revealing a multiple system of four radio sources suspected to be YSOs in a region of only ~4 arcsecs (1200 AU) in extent. The 3.6 cm observations show that the previously detected source VLA 2 contains a close (separation ~0.29 arcsecs or ~90 AU) radio binary, with components (A and B) along a position angle of ~150 degrees. The northern component (VLA 2A) of this binary system is also detected in the 7 mm observations, with a positive spectral index between 3.6 cm and 7 mm. In addition, the source VLA 2A is associated with extended emission along a position angle of ~115 degrees, that we interpret as outflowing shock-ionized gas that is exciting a system of HH objects with the same position angle. A third, weak 3.6 cm source, VLA 2C, that is detected also at 7 mm, is located ~0.7 arcsecs northeast of VLA 2A, and is possibly associated with the water maser emission in the region. The 7 mm observations reveal the presence of an additional source, VLA 2D, located ~3.5 arcsecs southeast of VLA 2A, and with a 1.35 mm counterpart. All these radio continuum sources have a positive spectral index, compatible with them being YSOs. We also propose that the high velocity CO emission observed in the region could be the superposition of multiple outflows (at least three independent bipolar outflows) excited by the YSOs located at the core, instead of the previous interpretations in terms of only one or two outflows.Comment: Accepted for publication in The Astrophysical Journal (2007 December 6

    Managing Hypertension, Diabetes, and Cardiovascular Disease Risk via Short-Term Medical Trips: A Retrospective Longitudinal Study in Santo Domingo

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    Background: Short-term medical trips (STMTs) from high-resource countries frequently provide care in low and middle-income countries. Little existing literature objectively tracks the long-term outcomes of these interventions on the receiving populations over time to assess potential benefits and to ensure no harm is being done. Objectives: The purpose of this study was to objectively analyze the outcomes of a biannual STMT to Santo Domingo, Dominican Republic on hypertension (HTN), diabetes mellitus type 2 (DM2), and cardiovascular disease (CVD) risk over a five-year period (2015-2019). Methods: Data from 1655 patients was extracted from the electronic medical record. In patients who received treatment and had more than one visit, a linear mixed model was used to analyze effects on systolic blood pressure (SBP) and hemoglobin A1C (HbA1C) values over time. In patients with high CVD risk based on a non-laboratory-based assessment, provider compliance with prescribing an aspirin and statin was calculated and tracked over time. Results: In patients with HTN who received treatment, average SBP was 148.83 mmHg (SD = 23.96) at initial visit and demonstrated no change over time (Estimate: 0.68 mmHg/year increase, p = 0.46). HbA1C data was insufficient for analysis. Treatment for patients with high CVD risk with an aspirin and statin improved from 41.46% in 2015 to 70.51% in 2019. Conclusion: SBP in patients with HTN treated by this STMT demonstrated no significant change over time. Possible contributing factors included patient education, access and adherence to medications, and documentation of data. Provider compliance with appropriate prescribing was high for patients with HTN and DM2 and improved over time for patients with high CVD risk, serving as an indirect measure for potential long-term benefits on these populations. All STMTs should objectively track outcomes of their interventions to assess risks and benefits to the communities being served

    Brain Interconnections

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    The interaction brain-machine is now an indissoluble fact. The repercussions this fact will have in future are presently unimaginable. As mentioned in [1] the nerve axon can now be modeled by a cable or a planar high speed interconnection, no matter what kind of interconnection will be used.  The brain development is clearly shown in a stupendous book of the SOCIETY FOR NEUROSCIENCE treating the brain and the nervous system. An extraction of the brain development chapter is here included to show the relationship among the physiological brain connections [2] and the high speed electrical connections [1]. On the other hand, because of the massive volume of information storage now a day the synchronization clock speeds are all in the range of GHz almost reaching the THz. At these very high frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift-effects caused by phenomena like cross talk, ringing, and overshoot are present and may be undesirable for the performance of a circuit or system. Thus, the interconnects do not have to be considered like simple conductors or lumped elements. All this gives rise to a new emerging discipline known as signal integrity. This discipline is extremely important to maintain the signal quality on microstrip circuits [3]. In this discipline the correct timing and signal quality preservation preventing transients and false switching are studied in order to avoid excessive delays
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