157 research outputs found
Physiological and Biochemical Aspects of Agrobacterium-Wheat (\u3ci\u3eTriticum aestivum\u3c/i\u3e L.) Interactions
Agrobacterium tumefaciens and A. rhizogenes are the causal agents of gall or hairy root disease, but normally the bacteria do not cause disease in wheat. However, both bacteria grew without inhibition when exposed to intact or wounded wheat roots or embryos, and they colonized wheat root surfaces to levels similar to dicotyledonous plants. A. tumefaciens and A. rhizogenes induced 23% cell death after a 1-h exposure to wheat embryo cells grown in 7.4 mM O2, while the extent of cell death at 2.1 mM 02 was 8%. Contact with A. tumefaciens or A. rhizogenes caused cultured wheat embryo and root cells to rapidly produce H202, which decreased when embryos and roots were cultured at 2.1 mM O2. Browning and autofluorescence, and an increase in ferulic acid in cell walls, were observed in wheat embryo and root epidermal cells exposed to Agrobacterium, but . neither lignin nor callose was detected. Agrobacterium appeared to induce resistance-like responses in wheat that may limit transformation efficiency.
The inability to regenerate wheat plants using tissue culture has been a limitation to high efficiency transformation. Regeneration via somatic embryogenesis was improved significantly by simulating the in ovulo environment to which the immature wheat embryos are exposed. Triticum embryo culture medium (TEC) improved callus formation, somatic embryo formation, and regeneration from somatic embryos while reducing precocious germination when compared to growth on Murashige and Skoog medium. Regeneration frequencies were improved when embryos were cultured at the O2 concentration found in the wheat ovule (2.1 mM O2) rather than atmospheric 02concentration (7.4 mM O2).
Agrobacterium-mediated transformation of wheat was limited by tissue necrosis following co-cultivation, and by poor plant regeneration. Reduction of necrosis and increased plant regeneration were accomplished by amending the culture medium with antioxidant compounds and by reducing the O2 tension in which the wheat embryos were cu1tured. Twelve days past anthesis (DPA), wheat embryos were co-cultivated with Agrobacterium tumefaciens strains WAg 11 or EHA 101, incubated on TEC medium containing antioxidant compounds (catalase, cysteine and ascorbic acid), and cultured at 2.1 mM O2 concentrations. Transformation was documented in 6.0% ofregeneratedA. tumefaciens WAg 11 exposed wheat plants using the firefly luciferase (luc) reporter system
Retroactive comparison of operator-designed and computer-generated skid-trail networks on steep terrain
Aim of the study: Quantify potential economic benefits of implementing computer-generated skid-trail networks over the traditional operator-designed skid-trail networks on steep terrain ground-based forest operations.Area of study: A 132-ha harvest operation conducted at the University of Kentucky’s Robinson Forest in eastern Kentucky, USA.Materials and methods: We compared computer-generated skid-trail network with an operator-designed network for a 132-ha harvest. Using equipment mounted GPS data and a digital elevation model (DEM), we identified the original operator-designed skid-trail network. Pre-harvest conditions were replicated by re-contouring terrain slopes over skid-trails to simulate the natural topography and by spatially distributing the harvestable volume based on pre-harvest inventories and timber harvest records. An optimized skid-trail network was designed using these pre-harvest conditions and compared to the original, operator-designed network.Main results: The computer-generated network length was slightly longer than the operator-designed network (53.7 km vs. 51.7 km). This also resulted in a slightly longer average skidding distance (0.71 km vs. 0.66 km) and higher total harvesting costs (5.1 ton-1). However, skidding costs of the computer-generated network were slightly lower (4.2 ton-1). When comparing only major skid-trails, those with ≥ 20 machine passes, the computer-generated skid-trail network was 28% shorter than the operator network (9.4 km vs. 13.1 km). Research highlight: This assessment offers evidence that computer-generated networks could be used to generate efficient skid-trails, help determine skidding costs, and assess further potential economic and environmental benefits.Key words: timber harvesting; forest operations; network optimization; soil disturbances; cost minimization
Improving Woody Biomass Estimation Efficiency Using Double Sampling
Although double sampling has been shown to be an effective method to estimate timber volume in forest inventories, only a limited body of research has tested the effectiveness of double sampling on forest biomass estimation. From forest biomass inventories collected over 9,683 ha using systematic point sampling, we examined how a double sampling scheme would have affected precision and efficiency in these biomass inventories. Our results indicated that double sample methods would have yielded biomass estimations with similar precision as systematic point sampling when the small sample was ≥ 20% of the large sample. When the small to large sample time ratio was 3:1, relative efficiency (a combined measure of time and precision) was highest when the small sample was a 30% subsample of the large sample. At a 30% double sample intensity, there was a \u3c 3% deviation from the original percent margin of error and almost half the required time. Results suggest that double sampling can be an efficient tool for natural resource managers to estimate forest biomass
Switchgrass (\u3ci\u3ePanicum virgatum\u3c/i\u3e L.) polyubiquitin gene (\u3ci\u3ePvUbi1\u3c/i\u3e and \u3ci\u3ePvUbi2\u3c/i\u3e) promoters for use in plant transformation
Abstract Background
The ubiquitin protein is present in all eukaryotic cells and promoters from ubiquitin genes are good candidates to regulate the constitutive expression of transgenes in plants. Therefore, two switchgrass (Panicum virgatum L.) ubiquitin genes (PvUbi1 and PvUbi2) were cloned and characterized. Reporter constructs were produced containing the isolated 5\u27 upstream regulatory regions of the coding sequences (i.e. PvUbi1 and PvUbi2 promoters) fused to the uidA coding region (GUS) and tested for transient and stable expression in a variety of plant species and tissues. Results
PvUbi1 consists of 607 bp containing cis-acting regulatory elements, a 5\u27 untranslated region (UTR) containing a 93 bp non-coding exon and a 1291 bp intron, and a 918 bp open reading frame (ORF) that encodes four tandem, head -to-tail ubiquitin monomer repeats followed by a 191 bp 3\u27 UTR. PvUbi2 consists of 692 bp containing cis-acting regulatory elements, a 5\u27 UTR containing a 97 bp non-coding exon and a 1072 bp intron, a 1146 bp ORF that encodes five tandem ubiquitin monomer repeats and a 183 bp 3\u27 UTR. PvUbi1 and PvUbi2 were expressed in all examined switchgrass tissues as measured by qRT-PCR. Using biolistic bombardment, PvUbi1 and PvUbi2 promoters showed strong expression in switchgrass and rice callus, equaling or surpassing the expression levels of the CaMV 35S, 2x35S, ZmUbi1, and OsAct1 promoters. GUS staining following stable transformation in rice demonstrated that the PvUbi1 and PvUbi2 promoters drove expression in all examined tissues. When stably transformed into tobacco (Nicotiana tabacum), the PvUbi2+3 and PvUbi2+9 promoter fusion variants showed expression in vascular and reproductive tissues. Conclusions
The PvUbi1 and PvUbi2 promoters drive expression in switchgrass, rice and tobacco and are strong constitutive promoter candidates that will be useful in genetic transformation of monocots and dicots
Perovskite-perovskite tandem photovoltaics with optimized bandgaps
We demonstrate four and two-terminal perovskite-perovskite tandem solar cells
with ideally matched bandgaps. We develop an infrared absorbing 1.2eV bandgap
perovskite, , that can deliver 14.8 %
efficiency. By combining this material with a wider bandgap
material, we reach monolithic two
terminal tandem efficiencies of 17.0 % with over 1.65 volts open-circuit
voltage. We also make mechanically stacked four terminal tandem cells and
obtain 20.3 % efficiency. Crucially, we find that our infrared absorbing
perovskite cells exhibit excellent thermal and atmospheric stability,
unprecedented for Sn based perovskites. This device architecture and materials
set will enable 'all perovskite' thin film solar cells to reach the highest
efficiencies in the long term at the lowest costs
A major grain protein content locus on barley (Hordeum vulgare L.) chromosome 6 influences flowering time and sequential leaf senescence
Timing of various developmental stages including anthesis and whole-plant (‘monocarpic’) senescence influences yield and quality of annual crops. While a correlation between flowering/seed filling and whole-plant senescence has been observed in many annuals, it is unclear how the gene networks controlling these processes interact. Using near-isogenic germplasm, it has previously been demonstrated that a grain protein content (GPC) locus on barley chromosome 6 strongly influences the timing of post-anthesis flag leaf senescence, with high-GPC germplasm senescing early. Here, it is shown that the presence of high-GPC allele(s) at this locus also accelerates pre-anthesis plant development. While floral transition at the shoot apical meristem (SAM; determined by the presence of double ridges) occurred simultaneously, subsequent development was faster in the high- than in the low-GPC line, and anthesis occurred on average 5 d earlier. Similarly, sequential (pre-anthesis) leaf senescence was slightly accelerated, but only after differences in SAM development became visible. Leaf expression levels of four candidate genes (from a list of genes differentially regulated in post-anthesis flag leaves) were much higher in the high-GPC line even before faster development of the SAM became visible. One of these genes may be a functional homologue of Arabidopsis glycine-rich RNA-binding protein 7, which has previously been implicated in the promotion of flowering. Together, the data establish that the GPC locus influences pre- and post-anthesis barley development and senescence, and set the stage for a more detailed analysis of the interactions between the molecular networks controlling these important life history traits
Yorkshire Enhanced Stop Smoking study (YESS): a protocol for a randomised controlled trial to evaluate the effect of adding a personalised smoking cessation intervention to a lung cancer screening programme
Introduction:Integration of smoking cessation (SC) into lung cancer screening (LCS) is essential to optimise clinical and cost effectiveness. The most effective way to use this “teachable moment” is unclear. The Yorkshire Enhanced Stop Smoking study (YESS) will measure the effectiveness of a SC service integrated within the Yorkshire Lung Screening Trial (YLST) and will test the efficacy of a personalised SC intervention, incorporating incidental findings detected on the low-dose computed tomography scan performed as part of YLST.Methods and analysis: Unless explicitly declined, all smokers enrolled in YLST will see a Smoking Cessation Practitioner (SCP) at baseline and receive smoking cessation support over 4-weeks comprising behavioural support, pharmacotherapy and/or a commercially available e-cigarette. Eligible smokers will be randomised (1:1 in permuted blocks of random size up to size 6) to receive either an enhanced, personalised smoking cessation support package, including CT scan images, or continued SBP. Anticipated recruitment is 1040 smokers (January 2019 – December 2020). The primary objective is to measure 7-day point prevalent carbon monoxide (CO) validated smoking cessation after 3-months. Secondary outcomes include CO validated cessation at 4-weeks and 12-months, self-reported continuous cessation at 4-weeks, 3-month and 12-months, attempts to quit smoking and changes in psychological variables, including perceived risk of lung cancer, motivation to quit smoking tobacco, confidence and efficacy beliefs (self and response) at all follow up points. A process evaluation will explore under which circumstances and on which groups the intervention works best, test intervention fidelity and theory test the mechanisms of intervention impact.Ethics and dissemination: This study has been approved by the East Midlands-Derby Research Ethics Committee (18/EM/0199) and the Health Research Authority/Health and Care Research Wales. Results will be disseminated through publication in peer-reviewed scientific journals, presentation at conferences and via the YLST website. Trial registration number: ISRCTN63825779; NIH ClinicalTrials.gov NCT0375011
The Vehicle, Fall 1984
Vol. 26, No. 1
Table of Contents
Thoughts on I-57Jim Caldwellpage 3
A Night Between Lonely and BlindJennifer K. Soulepage 4
What is Unnatural is Sometimes MagicAngelique Jenningspage 4
Cutting ClosenessBecky Lawsonpage 5
PhotoBrian Ormistonpage 6
The Sensuality of Corn One Week in AugustMichelle Mitchellpage 7
American MusicJim Caldwellpage 7
Water is WaitingMichael Kuopage 8
WhereJennifer K. Soulepage 8
The Fishing HoleJan Kowalskipage 9
Miller\u27s PondSue Gradypage 9
PhotoCathy Stonerpage 11
Young Man Reading To His LoverMaggie Kennedypage 11
ShellsChristopher R. Albinpage 12
In The ShadeJohn Fehrmannpage 12
FallLynanne Feilenpage 13
IndecisionDave L. Brydenpage 13
Dark Falls SoftlyAngelique Jenningspage 14
Not a Parked \u2757 Chevy in the Summer in the CountryMichelle Mitchellpage 20
BirdAnnie Heisepage 20
Clouds Created Only For Poets And Certain WomenJennifer K. Soulepage 21
SandGraham Lewispage 22
PhotoFred Zwickypage 23
Judgment CallCathy Moepage 23
I was hip that night Dan Hintzpage 24
A Sight Of WindDan Von Holtenpage 25
Tillard Isabel M. Parrottpage 26
The WidowMaggie Kennedypage 27
The SeparationMichelle Mitchellpage 27
The Garden Hose TrialMaggie Kennedypage 28
InterruptionsJennifer K. Soulepage 28
On Happening Across Jesus While Cleaning the BasementMaggie Kennedypage 29
GileonMichelle Mitchellpage 30
If My Father Were A Writer, He Would Still BuildAngelique Jenningspage 36
A Visit to Grandpa Gib\u27s HouseTammy Veachpage 37
For Having SeenAngelique Jenningspage 38
PhotoJudy Klancicpage 39
The Earth in BlueSusan J. Bielskypage 39
Things I Could Have SaidAngelique Jenningspage 40
AcrosticsAnnie Heisepage 40https://thekeep.eiu.edu/vehicle/1044/thumbnail.jp
The Vehicle, Fall 1984
Vol. 26, No. 1
Table of Contents
Thoughts on I-57Jim Caldwellpage 3
A Night Between Lonely and BlindJennifer K. Soulepage 4
What is Unnatural is Sometimes MagicAngelique Jenningspage 4
Cutting ClosenessBecky Lawsonpage 5
PhotoBrian Ormistonpage 6
The Sensuality of Corn One Week in AugustMichelle Mitchellpage 7
American MusicJim Caldwellpage 7
Water is WaitingMichael Kuopage 8
WhereJennifer K. Soulepage 8
The Fishing HoleJan Kowalskipage 9
Miller\u27s PondSue Gradypage 9
PhotoCathy Stonerpage 11
Young Man Reading To His LoverMaggie Kennedypage 11
ShellsChristopher R. Albinpage 12
In The ShadeJohn Fehrmannpage 12
FallLynanne Feilenpage 13
IndecisionDave L. Brydenpage 13
Dark Falls SoftlyAngelique Jenningspage 14
Not a Parked \u2757 Chevy in the Summer in the CountryMichelle Mitchellpage 20
BirdAnnie Heisepage 20
Clouds Created Only For Poets And Certain WomenJennifer K. Soulepage 21
SandGraham Lewispage 22
PhotoFred Zwickypage 23
Judgment CallCathy Moepage 23
I was hip that night Dan Hintzpage 24
A Sight Of WindDan Von Holtenpage 25
Tillard Isabel M. Parrottpage 26
The WidowMaggie Kennedypage 27
The SeparationMichelle Mitchellpage 27
The Garden Hose TrialMaggie Kennedypage 28
InterruptionsJennifer K. Soulepage 28
On Happening Across Jesus While Cleaning the BasementMaggie Kennedypage 29
GileonMichelle Mitchellpage 30
If My Father Were A Writer, He Would Still BuildAngelique Jenningspage 36
A Visit to Grandpa Gib\u27s HouseTammy Veachpage 37
For Having SeenAngelique Jenningspage 38
PhotoJudy Klancicpage 39
The Earth in BlueSusan J. Bielskypage 39
Things I Could Have SaidAngelique Jenningspage 40
AcrosticsAnnie Heisepage 40https://thekeep.eiu.edu/vehicle/1044/thumbnail.jp
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