Nutrient and hormone levels in Douglas-fir corrosion cavities, megagametophytes, and embryos during embryony

2005 ◽  
Vol 35 (10) ◽  
pp. 2447-2456 ◽  
Author(s):  
John G Carman ◽  
Gordon Reese ◽  
Rodney J Fuller ◽  
Timnit Ghermay ◽  
Roger Timmis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dry Mass ◽  
Douglas Fir ◽  
Chemical Analyses ◽  
Dynamic Changes ◽  
Hormone Levels ◽  
Corrosion Cavity ◽  
Novel Method ◽  
Indole 3 Acetic Acid

Gymnospermous embryos are nourished by fluids secreted from the megagametophyte. During early embryony, these fluids occupy the newly formed corrosion cavity. We describe a novel method for extracting corrosion cavity fluid and provide chemical analyses based on extractions from approximately 120 000 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) megagametophytes. Levels of potassium, phosphorus, calcium, zinc, and iron were higher in corrosion cavity fluid than in whole tissue, but levels of sulphur and manganese were lower. Levels of cyclitols, sucrose equivalents, erythrose, and arabinose were many-fold higher in corrosion cavity fluid than in whole tissues. Ala, Ser, Arg, Glx, and NH3 exceeded 80 mmol/kg dry mass in corrosion cavity fluid. These levels were about 100-fold higher than those found in whole tissues. During early embryony, hormone levels in corrosion cavity fluid were higher than levels observed in whole megagametophytes by 120-fold for indole-3-acetic acid, 53-fold for abscisic acid, and 8- to 10-fold for cytokinins. Nutrient and hormone levels tended to be much higher in the corrosion cavity fluid than would have been predicted based on whole-tissue analyses. Dynamic changes in nutrient and hormone levels occurred over time in the corrosion cavity, and these changes may normalize embryony in situ.

No Correlation between Latewood Formation and Leader Growth in Douglas-Fir Saplings

IAWA Journal ◽  
2006 ◽  
Vol 27 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Heidi J. Renninger ◽  
Barbara L. Gartner ◽  
Amy T. Grotta
Keyword(s):  
Pseudotsuga Menziesii ◽  
Cell Expansion ◽  
Growing Season ◽  
Height Growth ◽  
Douglas Fir ◽  
Cambial Zone ◽  
Wood Strength ◽  
And Storage ◽  
Cell Wall Deposition ◽  
Indole 3 Acetic Acid

The width of earlywood and latewood in conifer xylem may have a profound effect on water transport and storage, vulnerability to embolism, and wood strength, yet the controls over the timing of latewood formation are unclear. Tracheids differentiating in the cambial zone are influenced by IAA, indole-3 acetic acid, the radial concentration gradient of which appears to either increase cell expansion (earlywood) or increase cell wall deposition (latewood). There are suggestive data that latewood begins to form when the growth of the leader stops, but definitive results are lacking. Height growth was measured in 14 Douglas-fir (Pseudotsuga menziesii) saplings at 10 dates between May and August, from the beginning of the growing season until after height growth had ceased. The cambium was also pinned six times between June and July, to induce xylem scarring at known dates. After height growth ceased, saplings were harvested and transverse sections of the wood were made at the pin insertion points. The date at which 95% of the height growth had occurred and the date at which latewood formation had begun were estimated. Analysis showed no correlation of these data, suggesting that the two phenomena may occur around the same time, but that one is not causal of the other.

Firebrand generation from burning vegetation

2007 ◽  
Vol 16 (4) ◽  
pp. 458 ◽  
Author(s):  
Samuel L. Manzello ◽  
Alexander Maranghides ◽  
William E. Mell
Keyword(s):  
Mass Distribution ◽  
Pseudotsuga Menziesii ◽  
Tree Height ◽  
Dry Mass ◽  
Douglas Fir ◽  
Large Fire ◽  
Precision Balance ◽  
Real Scale ◽  
Fire Laboratory ◽  
Fire Experiments

A series of real-scale fire experiments were performed to determine the size and mass distribution of firebrands generated from Douglas-fir (Pseudotsuga menziesii) trees. The experiments were performed in the Large Fire Laboratory at the National Institute of Standards and Technology. The Douglas-fir trees used for the experiments ranged in total height from 2.6 to 5.2 m and the tree moisture content was varied. An array of pans filled with water was used to collect the firebrands that were generated from the burning trees. This ensured that firebrands would be quenched as soon as they made contact with the pans. The firebrands were subsequently dried and the sizes were measured using callipers and the dry mass was determined using a precision balance. For all experiments performed, the firebrands were cylindrical in shape. The average firebrand size measured from the 2.6-m Douglas-fir trees was 3 mm in diameter, 40 mm in length. The average firebrand size measured for the 5.2-m Douglas-fir trees was 4 mm in diameter with a length of 53 mm. The mass distribution of firebrands produced from two different tree sizes under similar tree moisture levels was similar. The only noticeable difference occurred in the largest mass class. Firebrands with masses up to 3.5 g to 3.7 g were observed for the larger tree height used (5.2 m). The surface area of the firebrands scaled with firebrand weight.

scholarly journals Label-Free and Quantitative Dry Mass Monitoring for Single Cells during In Situ Culture

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1635
Author(s):  
Ya Su ◽  
Rongxin Fu ◽  
Wenli Du ◽  
Han Yang ◽  
Li Ma ◽  
...  
Keyword(s):  
Cell Growth ◽  
Single Cell ◽  
Hela Cells ◽  
Quantitative Measurement ◽  
Single Cells ◽  
Dry Mass ◽  
Quantitative Detection ◽  
Label Free ◽  
Mass Sensitivity

Quantitative measurement of single cells can provide in-depth information about cell morphology and metabolism. However, current live-cell imaging techniques have a lack of quantitative detection ability. Herein, we proposed a label-free and quantitative multichannel wide-field interferometric imaging (MWII) technique with femtogram dry mass sensitivity to monitor single-cell metabolism long-term in situ culture. We demonstrated that MWII could reveal the intrinsic status of cells despite fluctuating culture conditions with 3.48 nm optical path difference sensitivity, 0.97 fg dry mass sensitivity and 2.4% average maximum relative change (maximum change/average) in dry mass. Utilizing the MWII system, different intrinsic cell growth characteristics of dry mass between HeLa cells and Human Cervical Epithelial Cells (HCerEpiC) were studied. The dry mass of HeLa cells consistently increased before the M phase, whereas that of HCerEpiC increased and then decreased. The maximum growth rate of HeLa cells was 11.7% higher than that of HCerEpiC. Furthermore, HeLa cells were treated with Gemcitabine to reveal the relationship between single-cell heterogeneity and chemotherapeutic efficacy. The results show that cells with higher nuclear dry mass and nuclear density standard deviations were more likely to survive the chemotherapy. In conclusion, MWII was presented as a technique for single-cell dry mass quantitative measurement, which had significant potential applications for cell growth dynamics research, cell subtype analysis, cell health characterization, medication guidance and adjuvant drug development.

scholarly journals Development of a novel method for the in-situ dechlorination of immovable iron elements: optimization of Cl− extraction yield through experimental design

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Veneranda ◽  
Nagore Prieto-Taboada ◽  
Jose Antonio Carrero ◽  
Ilaria Costantini ◽  
Aitor Larrañaga ◽  
...  
Keyword(s):  
Experimental Design ◽  
Optimization Design ◽  
Degradation Process ◽  
Extraction Yield ◽  
Alkaline Solutions ◽  
Iron Core ◽  
Total Consumption ◽  
Iron Leaching ◽  
Novel Method

AbstractThe conservation of iron objects exposed to marine aerosol is threatened by the formation of akaganeite, a highly unstable Cl-bearing corrosion phase. As akaganeite formation is responsible of the exfoliation of the rust layer, chlorides trigger a cyclic alteration phenomenon that often ends with the total consumption of the iron core. To prevent this degradation process, movable iron elements (e.g. archaeometallurgical artefacts) are generally immersed in alkaline dechlorination baths. Aiming to transfer this successful method to the treatment of immovable iron objects, we propose the in-situ application of alkaline solutions through the use of highly absorbent wraps. As first step of this novel research line, the present work defines the best desalination solution to be used and optimizes its extraction yield. After literature review, a screening experimental design was performed to understand the single and synergic effects of common additives used for NaOH baths. Once the most effective variables were selected, an optimization design was carried out to determine the optimal conditions to be set during treatment. According to the experimental work here presented, the use of 0.7 M NaOH solutions applied at high temperatures (above 50 °C) is recommended. Indeed, these conditions enhance chloride extraction and iron leaching inhibition, while promoting corrosion stabilization.

scholarly journals Using Sentinel-2 Images to Estimate Topography, Tidal-Stage Lags and Exposure Periods over Large Intertidal Areas

2021 ◽  
Vol 13 (2) ◽  
pp. 320
Author(s):  
José P. Granadeiro ◽  
João Belo ◽  
Mohamed Henriques ◽  
João Catalão ◽  
Teresa Catry
Keyword(s):  
Large Scale ◽  
Exposure Period ◽  
Intertidal Area ◽  
Digital Elevation ◽  
Geographical Bias ◽  
Novel Method ◽  
Tidal Stage ◽  
Sentinel 2

Intertidal areas provide key ecosystem services but are declining worldwide. Digital elevation models (DEMs) are important tools to monitor the evolution of such areas. In this study, we aim at (i) estimating the intertidal topography based on an established pixel-wise algorithm, from Sentinel-2 MultiSpectral Instrument scenes, (ii) implementing a set of procedures to improve the quality of such estimation, and (iii) estimating the exposure period of the intertidal area of the Bijagós Archipelago, Guinea-Bissau. We first propose a four-parameter logistic regression to estimate intertidal topography. Afterwards, we develop a novel method to estimate tide-stage lags in the area covered by a Sentinel-2 scene to correct for geographical bias in topographic estimation resulting from differences in water height within each image. Our method searches for the minimum differences in height estimates obtained from rising and ebbing tides separately, enabling the estimation of cotidal lines. Tidal-stage differences estimated closely matched those published by official authorities. We re-estimated pixel heights from which we produced a model of intertidal exposure period. We obtained a high correlation between predicted and in-situ measurements of exposure period. We highlight the importance of remote sensing to deliver large-scale intertidal DEM and tide-stage data, with relevance for coastal safety, ecology and biodiversity conservation.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

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