Quantitative Histochemical Analysis of Starch, Malate and K+, together with the Activity of Phospho-enolpyruvate Carboxylase along an Elongating Primary Leaf of Hordeum vulgare

1987 ◽  
Vol 42 (9-10) ◽  
pp. 1092-1096 ◽  
Author(s):  
R. Hampp ◽  
W. H. Outlaw ◽  
H. Ziegler
Keyword(s):  
Starch Content ◽  
Solute Concentration ◽  
Leaf Base ◽  
Histochemical Analysis ◽  
Specific Nature ◽  
Mesophyll Cells ◽  
Equivalent Basis ◽  
Intercalary Meristem ◽  
Minor Portion ◽  
A Minor

The content of starch, malate, potassium and the activity of phospho-enolpyruvate carboxylase (PEPC) were analyzed by quantitative histochemistry in mesophyll cells of different zones along the axis of lyophylized primary elongating leaves of barley. The concentrations of potassium and malate were low in the region of the intercalary meristem (close to the point of grain attachment), but concentrations of solutes increased abruptly and stoichiometrically (equivalent basis) in the elongation zone (2 to 10 mm from the leaf base), where they contributed approximately -0.17 megapascal to the solute potential. Although this solute concentration represents only a minor portion of the reported solute potential, the specific nature of the change, its correlation with a decrease of starch content, and the distribution of the activity of PEPC indicate cell expansion in barley could be augmented by a potassium malate osmoregulatory system that utilizes starch as a source of carbon skeletons.

scholarly journals Studying the present-day dynamics of Lena delta by space images

2019 ◽  
Vol 46 (6) ◽  
pp. 567-574
Author(s):  
V. I. Kravtsova ◽  
A. N. Inyushin
Keyword(s):  
Marine Terrace ◽  
Southwestern Part ◽  
Space Images ◽  
Delta Coastline ◽  
Local Erosion ◽  
Minor Portion ◽  
Landsat Satellite ◽  
A Minor ◽  
Erosion Material ◽  
Lena Delta

The dynamics of Lena delta coastline since the late XX century up to the present time have been studied using Landsat satellite data. The comparison of different-time images of morphologically different segments of the delta coastline has shown the major portion of the delta to be stable. Minimal changes have been recorded near the mouths of the branches carrying a minor portion of the Lena runoffthe Olenekskaya and Tumatskie. In the eastern part of the delta, near the mouths of copious branches Trofimovskaya and Bykovskaya, no changes have taken place, as well as in its western part, which is represented by a part of abrasion marine terrace embraced by the delta. In the southwestern part, in the Olenek delta, the delta coastline has been eroded with the erosion material transported eastward by along-shore current. Near the mouths of the Tumatskaya branch, the forms of marine accumulation are unstable, and the marine terrace in the northeastern part of the delta shows a minor local erosion. The periods of erosion in different delta areas are not synchronous and the eroded zones are not large in size. No increment in the land, nor shore progradation have been seen.

scholarly journals Transcripts repressed at the stop of phloem unloading highlight the energy efficiency of sugar import in the ripening V. vinifera fruit.

2021 ◽  
Author(s):  
Stefania Savoi ◽  
Laurent Torregrosa ◽  
Charles Romieu
Keyword(s):  
Cell Wall ◽  
Regulatory Elements ◽  
Solute Concentration ◽  
Growth Patterns ◽  
Individual Growth ◽  
Sugar Accumulation ◽  
Minor Role ◽  
Phloem Unloading ◽  
Sugar Transporters ◽  
A Minor

AbstractTranscriptomic changes at the cessation of sugar accumulation in the pericarp of Vitis vinifera were addressed on single berries re-synchronized according to their individual growth patterns. The net rates of water, sugars and K+ accumulation inferred from individual growth and solute concentration confirmed that these inflows stopped simultaneously in the ripe berry, while the small amount of malic acid remaining at this stage was still being oxidized at a low rate. Resynchronized individual berries displayed negligible variations in gene expression among triplicates. RNA-Seq studies revealed sharp reprogramming of cell wall enzymes and structural proteins, associated with an 80% repression of specific sugar transporters and aquaporins on the plasma or tonoplast membranes, at the stop of phloem unloading in the three genotypes and two environments investigated. The prevalence of SWEET transporters suggests that electrogenic transporters would just play a minor role on the plasma membrane of SE/CC complex, and the one of the flesh, while sucrose/H+ exchangers dominate on its tonoplast. Cis-regulatory elements present in their promoters allowed to sort these transporters in different groups, also including specific TIPs and PIPs paralogs, and cohorts of cell wall related genes. These results lead us to propose which structural, developmental and energy adaptations would give this fruit such a power of attraction for water and photoassimilates.

Compensatory effect of the heat increment of feeding on thermoregulation costs of white-tailed deer fawns in winter

1999 ◽  
Vol 77 (9) ◽  
pp. 1474-1485 ◽  
Author(s):  
Paul G Jensen ◽  
Peter J Pekins ◽  
James B Holter
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Resting Metabolic Rate ◽  
Energetic Cost ◽  
Critical Temperatures ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Minor Portion ◽  
A Minor

For northern white-tailed deer (Odocoileus virginianus) fawns, the energetic cost of thermoregulation (HcE) during severe winters can result in substantial catabolism of body-tissue reserves. The heat increment of feeding (HiE) has the potential to offset thermoregulatory energy expenditure that would otherwise require the catabolism of these reserves. During winters 1996 and 1997, we conducted 18 fasting and 18 on-feed heat-production trials using indirect respiration calorimetry in a metabolic chamber. Nonlinear regression analysis was used to estimate the lower critical temperatures (Tlc) and determine the fasting metabolic rate (FMR) and resting metabolic rate (RMR). Resulting models were used to calculate HiE, HcE, and percent substitution of HiE for HcE. For fawns fed a natural browse diet, estimated FMR and RMR were 352 and 490 kJ·kg body mass (BM)-0.75·d-1, respectively; this 40% increase in thermoneutral heat production reduced Tlc from -0.8 to -11.2°C between the fasted and fed states, respectively, and reduced HcE by 59% for fed fawns. For fawns fed a concentrate diet, estimated FMR and RMR were 377 and 573 kJ·kg BM-0.75·d-1, respectively. Level of browse intake had a significant effect on RMR andTlc. RMR was 12% higher for fawns on a high versus a low level of intake, and estimated Tlc was -15.6 and -5.8°C, respectively. Our data indicate that the energetic cost of thermoregulation is probably a minor portion of the energy budget of a healthy fawn consuming natural forage.

Protein kinase-dependent and Ca2+-independent cAMP inhibition of ANP release in beating rabbit atria

2002 ◽  
Vol 282 (5) ◽  
pp. R1477-R1489 ◽  
Author(s):  
Xun Cui ◽  
Jin Fu Wen ◽  
Jing Yu Jin ◽  
Wen Xie Xu ◽  
Sung Zoo Kim ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Mechanical Stretch ◽  
Dependent Manner ◽  
Calmodulin Kinase ◽  
Minor Portion ◽  
Channel Dependent ◽  
A Minor ◽  
The Relationship ◽  
Rabbit Atria

Regulation of atrial release of atrial natriuretic peptide (ANP) is coupled to changes in atrial dynamics. However, the mechanism by which mechanical stretch controls myocytic ANP release must be defined. The purpose of this study was to define the mechanism by which cAMP controls myocytic ANP release in perfused, beating rabbit atria. The cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX) inhibited myocytic ANP release. The activation of adenylyl cyclase with forskolin inhibited ANP release, which was a function of an increase in cAMP production. Inhibitors for L-type Ca2+ channels and protein kinase A (PKA) attenuated a minor portion of the forskolin-induced inhibition of ANP release. Gö-6976 and KN-62, which are specific inhibitors for protein kinase C-α and Ca2+/calmodulin kinase, respectively, failed to modulate forskolin-induced inhibition of ANP release. The nonspecific protein kinase inhibitor staurosporine blocked forskolin-induced inhibition of ANP release in a dose-dependent manner. Staurosporine but not nifedipine shifted the relationship between cAMP and ANP release. Inhibitors for L-type Ca2+ channels and PKA and staurosporine blocked forskolin-induced accentuation of atrial dynamics. These results suggest that cAMP inhibits atrial myocytic release of ANP via protein kinase-dependent and L-type Ca2+-channel-dependent and -independent signaling pathways.

Photosynthesis in Gomphrena celosioides and Its Classification Amongst C4-pathway Plants

1976 ◽  
Vol 3 (6) ◽  
pp. 863 ◽  
Author(s):  
E Repo ◽  
MD Hatch
Keyword(s):  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
C4 Species ◽  
Bundle Sheath Cells ◽  
Major Route ◽  
Gomphrena Celosioides ◽  
A Minor ◽  
Sheath Cells

Monocotyledonous C4 species classified as NADP-ME-type transfer malate from mesophyll to bundle sheath cells where this acid is decarboxylated via NADP malic enzyme (EC 1.1.1.40) to yield pyruvate and CO2. The dicotyledon G. celosioides is most appropriately classified in thls group on the basis of high leaf activities of NADP malic enzyme and NADP malate dehydrogenase (EC 1.1.1.82). However, this species contains high aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) activities and centripetally located bundle sheath chloroplasts, features more typical of other groups of C4 species that cycle aspartate and alanine between mesophyll and bundle sheath cells. During the present study, we found that these aminotransferases and NADP malate dehydrogenase were predominantly located in mesophyll cells, that malate was the major C4 acid labelled when leaves were exposed to 14CO2, and that label was initially lost most rapidly from the C-4 of malate during a chase in 12CO2. These results are consistent with the major route of photosynthetic metabolism being the same as that operative in other NADP-ME-type species, although this may be supplemented by a minor route utilizing aspartate. In contrast to monocotyledonous NADP-ME-type C4 species, isolated bundle sheath cells from G. celosioides were capable of rapid photoreduction of NADP as judged by products formed during assimilation of 14CO2 and their capacity for light-dependent oxygen evolution. This was related to a relatively high frequency of single unstacked granum in the chloroplasts of these cells.

scholarly journals Fractionation and characterization of proteoglycans isolated from chondrocyte cell cultures

1981 ◽  
Vol 197 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Sven Björnsson ◽  
Dick Heinegȧrd
Keyword(s):  
Cell Culture ◽  
Chondroitin Sulphate ◽  
Calf Serum ◽  
Void Volume ◽  
Cartilage Tissue ◽  
Foetal Calf Serum ◽  
Nasal Cartilage ◽  
Core Proteins ◽  
Minor Portion ◽  
A Minor

Chondrocyte cultures were established from foetal bovine tracheal cartilage and maintained in Ham's F12 medium with or without 10% (v/v) foetal calf serum. The proteoglycans were isolated and characterized. (1) The proteoglycans from cultures both with and without serum distributed in associative or dissociative CsCl gradients like proteoglycans from cartilage tissue. (2) The amino acid composition, protein contents and glucosamine/galactosamine ratios were grossly identical with those of the tissue derived proteoglycans. (3) Sedimentation coefficients (s0) for the monomers were 21.0S and 22.7S from cultures without and with serum respectively. The s0 values obtained for aggregates were 72.3S and 93.2S respectively. The limiting viscosity numbers [η] were 248ml/g and 298ml/g respectively. These data corresponded well to those obtained for the tissue-derived proteoglycans. (4) The sizes of the core proteins and chondroitin sulphate chains respectively were the same for both types of cell-culture proteoglycans and similar to those of the tissue proteoglycans. Both the keratan sulphate-rich region and the hyaluronic acid-binding region were identified. The latter, however, was not resistant to limit digestion with trypsin, in contrast with the fragment derived from the bovine nasal cartilage. (5) About 70% of the cell-culture proteoglycans chromatographed in the void volume on a Sepharose 2B column, whereas reduced and alkylated samples (monomers) chromatographed completely included in the column. The two link proteins present in A1 preparations of cartilage proteoglycans were also present in A1 preparations of cell-culture proteoglycans. (6) A minor portion (10%) of the 35S-labelled proteoglycans in the cultures was associated with the cells. Reduced and alkylated samples were larger compared with the monomers in the medium, and chromatographed partly (25%) excluded on the Sepharose 2B column. A larger proportion (50%) of the non-reduced samples chromatographed in the void volume of the column.

Environmental and Economic Impacts of Nitrogen Trifluoride at an Idaho Semiconductor Facility

2020 ◽  
Author(s):  
Matthew A. Thompson ◽  
Amir Mohajeri ◽  
Amin Mirkouei
Keyword(s):  
Human Error ◽  
Ghg Emissions ◽  
Assessment Method ◽  
Solar Panels ◽  
Nitrogen Trifluoride ◽  
Point Of Use ◽  
Primary Driver ◽  
Minor Portion ◽  
A Minor ◽  
The Cost

Abstract Nitrogen Trifluoride (NF3) is an inorganic compound widely used in the electronics industry for manufacturing various products, such as semiconductors, solar panels, and touch screens. However, NF3 emissions that accumulate in the atmosphere have 17,200 times the global warming potentials of CO2 over a 100-year time horizon. The abatement efficiency for NF3 is high, although some amount of NOx is generated. This study aims to provide economic and environmental impact assessments on the use of NF3. Life cycle assessment method is applied for evaluating environmental aspects. Additionally, a real case study for the Idaho semiconductor facility is used to assess the method and demonstrate the application of this study. The results show that slight reductions in abatement efficiency have dramatic impacts on mitigating greenhouse gas (GHG) emissions. Even small unplanned releases of NF3, either through mechanical failure or human error, have significant environmental impacts, and every reasonable effort should be taken to avoid such incidents. The results also indicate that the cost of abatement is the primary driver of economic impact. It is found that the considerable distance from the chemical plant in Arizona to the point of use in Idaho contributed a minor portion of GHGs associated with the use of NF3. It is also found that contaminants (e.g., SF6 and CF4) within the cylinder potentially have more substantial GHG impacts than the actual NF3, owing in part to the relative ease with which NF3 is destroyed through abatement.

Influenza A Virus Subpopulations and Their Implication in Pathogenesis and Vaccine Development

2020 ◽  
Vol 8 (1) ◽  
pp. 247-267 ◽  
Author(s):  
Amir Ghorbani ◽  
John M. Ngunjiri ◽  
Chang-Won Lee
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Vaccine Development ◽  
Current Knowledge ◽  
Genomic Diversity ◽  
Biologically Active ◽  
Virus Particles ◽  
Live Attenuated Influenza Vaccine ◽  
Minor Portion ◽  
A Minor

The concept of influenza A virus (IAV) subpopulations emerged approximately 75 years ago, when Preben von Magnus described “incomplete” virus particles that interfere with the replication of infectious virus. It is now widely accepted that infectious particles constitute only a minor portion of biologically active IAV subpopulations. The IAV quasispecies is an extremely diverse swarm of biologically and genetically heterogeneous particle subpopulations that collectively influence the evolutionary fitness of the virus. This review summarizes the current knowledge of IAV subpopulations, focusing on their biologic and genomic diversity. It also discusses the potential roles IAV subpopulations play in virus pathogenesis and live attenuated influenza vaccine development.

scholarly journals Glacial lakes exacerbate Himalayan glacier mass loss

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Owen King ◽  
Atanu Bhattacharya ◽  
Rakesh Bhambri ◽  
Tobias Bolch
Keyword(s):  
Mass Loss ◽  
Regional Scale ◽  
High Mountain ◽  
Mass Balances ◽  
Glacial Lakes ◽  
Regional Variability ◽  
Glacier Recession ◽  
Minor Portion ◽  
A Minor ◽  
The Himalaya

AbstractHeterogeneous glacier mass loss has occurred across High Mountain Asia on a multi-decadal timescale. Contrasting climatic settings influence glacier behaviour at the regional scale, but high intra-regional variability in mass loss rates points to factors capable of amplifying glacier recession in addition to climatic change along the Himalaya. Here we examine the influence of surface debris cover and glacial lakes on glacier mass loss across the Himalaya since the 1970s. We find no substantial difference in the mass loss of debris-covered and clean-ice glaciers over our study period, but substantially more negative (−0.13 to −0.29 m w.e.a−1) mass balances for lake-terminating glaciers, in comparison to land-terminating glaciers, with the largest differences occurring after 2000. Despite representing a minor portion of the total glacier population (~10%), the recession of lake-terminating glaciers accounted for up to 32% of mass loss in different sub-regions. The continued expansion of established glacial lakes, and the preconditioning of land-terminating glaciers for new lake development increases the likelihood of enhanced ice mass loss from the region in coming decades; a scenario not currently considered in regional ice mass loss projections.

Selection of diet by sheep grazing semi-arid pastures on the Riverine Plain. 1. A bladder saltbush (Atriplex vesicaria)-cotton bush (Kochia aphylla) community

1966 ◽  
Vol 6 (23) ◽  
pp. 460 ◽  
Author(s):  
JH Leigh ◽  
WE Mulham
Keyword(s):  
Sheep Grazing ◽  
Merino Sheep ◽  
Minor Portion ◽  
A Minor ◽  
Associated Species ◽  
Visual Assessments ◽  
Semi Arid ◽  
Selection Of

The diet selected by Merino sheep grazing a bladder saltbush (Atriplex vesicaria Hew. ex Benth.)- cottonbush (Kochia aphylla R.Br.) community was determined by analysing extrusa from wethers fitted with oesophageal fistulas. Visual assessments were combined with hand clipped samples to determine the amount of forage available. The results showed that the dominant constituent of the pasture, bladder saltbush, was sparingly grazed, whereas many of the associated species, which often constituted only a minor portion of the total available forage, were heavily grazed.

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