Effect of osmotic potential on synthesis and secretion of polygalacturonase and cellulase by Geotrichum candidum

1987 ◽  
Vol 33 (2) ◽  
pp. 138-141 ◽  
Author(s):  
L. L. Davis ◽  
A. B. A. M. Baudoin
Keyword(s):  
Polyethylene Glycol ◽  
Osmotic Potential ◽  
Geotrichum Candidum ◽  
Major Effect ◽  
Minor Effect ◽  
Polyethylene Glycol 400 ◽  
Liquid Cultures ◽  
A Minor ◽  
Osmotic Potentials

In liquid cultures of Geotrichum candidum, amended with KCl, mannitol, or polyethylene glycol 400 to control osmotic potential, levels of both intracellular and extracellular endopolygalacturonase fell off rapidly with decreasing osmotic potential in the range of −0.5 to −2.5 MPa. Concentrations (units per millilitre) of intracellular endopolygalacturonase were higher than those of extracellular endopolygalacturonase at all osmotic potentials tested. The ratio of intracellular to extracellular endopolygalacturonase concentration increased with decreasing osmotic potential; this became most pronounced below −1.5 MPa. It appeared that the major effect of osmotic potential was on endopolygalacturonase synthesis with a minor effect on endopolygalacturonase secretion from the cell. Levels of intracellular and extracellular cellulase also decreased with decreasing osmotic potential, although the effect was much smaller than with endopolygalacturonase. However, the ratio of intracellular to extracellular cellulase concentration did not change significantly with changes in osmotic potential. This indicated that only the synthesis of cellulase was affected.

scholarly journals Hydrocarbon fluxes above a Scots pine forest canopy: measurements and modeling

2007 ◽  
Vol 7 (12) ◽  
pp. 3361-3372 ◽  
Author(s):  
J. Rinne ◽  
R. Taipale ◽  
T. Markkanen ◽  
T. M. Ruuskanen ◽  
H. Hellén ◽  
...  
Keyword(s):  
Scots Pine ◽  
Forest Canopy ◽  
Transport Model ◽  
Proton Transfer Reaction ◽  
Major Effect ◽  
Systematic Difference ◽  
Chemical Degradation ◽  
Research Station ◽  
Minor Effect ◽  
A Minor

Abstract. We measured the fluxes of several hydrocarbon species above a Scots pine (Pinus sylvestris) stand using disjunct eddy covariance technique with proton transfer reaction – mass spectrometry. The measurements were conducted during four days in July at SMEAR II research station in Hyytiälä, Finland. Compounds which showed significant emission fluxes were methanol, acetaldehyde, acetone, and monoterpenes. A stochastic Lagrangian transport model with simple chemical degradation was applied to assess the sensitivity of the above canopy fluxes to chemistry. According to the model, the chemical degradation had a minor effect on the fluxes measured in this study but may have a major effect on the vertical flux profiles of more reactive compounds, such as sesquiterpenes. The monoterpene fluxes derived using M81 and M137 had a systematic difference with the latter one being higher. These fluxes followed the traditional exponential temperature dependent emission algorithm but were considerably higher than the fluxes measured before at the same site. The normalized monoterpene emission potentials at 30°C, obtained using the temperature dependence coefficient of 0.09°C−1, were 2.0 μg gdw−1 h−1 and 2.5 μg gdw−1 h−1, for fluxes derived using M81 and M137.

Physiological responses of three northern conifers to rapid and slow induction of moisture stress

1985 ◽  
Vol 63 (7) ◽  
pp. 1171-1176 ◽  
Author(s):  
G. F. Buxton ◽  
D. R. Cyr ◽  
E. B. Dumbroff ◽  
D. P. Webb
Keyword(s):  
Polyethylene Glycol ◽  
Osmotic Potential ◽  
White Spruce ◽  
Moisture Stress ◽  
Jack Pine ◽  
Soil Drying ◽  
Mild Stress ◽  
Pressure Potential ◽  
Polyethylene Glycol 400 ◽  
Drought Period

The response of black and white spruce and jack pine to slow and rapid induction of moisture stress was evaluated during soil drying and exposure to liquid cultures containing polyethylene glycol 8000. Marked changes in water, osmotic, and pressure potentials were observed in all three species, but water potentials were the most sensitive indicators of moisture stress. Osmotic potentials were sensitive to mild stress in polyethylene glycol (−400 kPa), but they held relatively steady at higher stress intensities (−800 to −1600 kPa). Large decreases in osmotic potential were recorded in white spruce and jack pine during severe drying stress late in the drought period and these changes were accompanied by large decrements in water and pressure potentials. Significant changes in osmotic potential were not observed in black spruce prior to seedling death. Losses in pressure potential were only observed at −1600 kPa of polyethylene glycol stress, although wilting in young tissue was apparent at lower stress intensities. Pressure potentials of plants in the soil-drying test fell well below those recorded in the polyethylene glycol study. The highest resistance to loss of turgor and the maximum adjustment to moisture stress were observed in white spruce. Shoot growth and transpiration declined in the three conifers at relatively low stress intensities. Total chlorophyll and the chlorophyll stability index decreased during drought, but the differences recorded among species were not clearly related to observed differences in drought tolerance. Cation concentrations did not change during stress.

A Discussion of Iron Golf Club Head Inertia Tensors and Their Effects on the Golfer

1996 ◽  
Vol 12 (4) ◽  
pp. 449-469 ◽  
Author(s):  
Steven M. Nesbit ◽  
Terry A. Hartzell ◽  
John C. Nalevanko ◽  
Ryan M. Starr ◽  
Mathew G. White ◽  
...  
Keyword(s):  
Major Effect ◽  
Golf Swing ◽  
Golf Club ◽  
Minor Effect ◽  
Impact Function ◽  
Club Head ◽  
A Minor ◽  
The Impact ◽  
Flexible Model ◽  
Eccentric Impact

This paper discusses the inertia tensors of iron golf club heads and their influence on the swing of a golfer and the behavior of the golf club. Inertia tensors of various five-iron club head configurations were determined using solid modeling and were compared with equivalent solid ellipsoids. A golf swing and club behavior analysis was performed using a computer model comprised of a 3D parametric flexible model of a golf club driven with data from a recorded golf swing, and an impact function. The impact results were verified experimentally. The analysis without impact determined that altering club head inertia had a minor effect on the torque required to swing the club and the deflections of the club head at the time of impact. The analysis with an eccentric impact found that altering club head inertia had a major effect on transmitted forces and torques and a moderate effect on deflection of the club head.

scholarly journals KINETICS OF THROMBIN INACTIVATION AS INFLUENCED BY PHYSICAL CONDITIONS, TRYPSIN, AND SERUM

1940 ◽  
Vol 24 (2) ◽  
pp. 169-188 ◽  
Author(s):  
Anthony J. Glazko ◽  
John H. Ferguson
Keyword(s):  
Major Effect ◽  
Order Reaction ◽  
Minor Effect ◽  
Serum Tryptase ◽  
Experimental Conditions ◽  
First Order ◽  
Physical Conditions ◽  
A New Technique ◽  
A Minor ◽  
Kinetics Of

1. A new technique for studying the progressive inactivation of thrombin is described. 2. Thrombin inactivation follows the kinetics of a first order reaction. 3. The rate constant of the inactivation reaction increases with temperature and pH (5.0 → 10.0), and also with the presence of crystalline trypsin, or serum. The rate varies for different thrombin preparations, even under the same experimental conditions. 4. The temperature characteristics of the reaction indicate that thrombin is associated with protein. 5. Thrombin preparations are most stable at pH 4 to 5, even when trypsin or serum is added. 6. The progressive inactivation is believed to be due to two mechanisms: (1) a major effect, thought to be the action of a "serum-tryptase," which is usually present in the thrombin preparations, and (2) a minor effect, probably attributable to denaturation of thrombin-protein. 7. Sources of the thrombinolytic factor (serum-tryptase) and its implications in the general theory and practical problems of blood coagulation and antithrombic action are briefly discussed.

scholarly journals Effects of Delayed Mating and Access to Water on Oviposition and Longevity in Female Amyelois transitella

2014 ◽  
Vol 6 ◽  
pp. IJIS.S20688 ◽  
Author(s):  
Charles S. Burks
Keyword(s):  
Mating Disruption ◽  
Free Water ◽  
Central Valley ◽  
Field Measurements ◽  
Major Effect ◽  
Leslie Matrix ◽  
Management Technique ◽  
Minor Effect ◽  
Amyelois Transitella ◽  
A Minor

The navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is a key pest of high-value irrigated nut crops in the arid Central Valley of California. Mating disruption is an established pest management technique for this pest, with reduced non-target impacts. This study compared laboratory survivorship and fertility data with field measurements to improve understanding of factors determining abundance of this species in the presence and absence of mating disruption. While the relative humidity is generally higher in almond orchards compared to readings from meteorological stations, the data indicate little free water in the absence of irrigation. Access to free water has a minor effect on the fertility of females if they mate soon after emergence, but a major effect if mating is delayed for 7 days. Leslie matrix projections indicate that changes in adult survivorship have much less impact than changes in larval survivorship. These findings indicate that control tactics limiting reproduction and survival of immature stages are more important for this species than those targeting adults.

scholarly journals Model-based academic dismissal policies; a case-study from the Netherlands

2018 ◽  
Author(s):  
Casper J Albers ◽  
Carlien Vermue ◽  
Taco de Wolff ◽  
Hans Beldhuis
Keyword(s):  
The Netherlands ◽  
Optimal Level ◽  
Major Effect ◽  
Bachelor's Degree ◽  
First Year ◽  
Minor Effect ◽  
Academic Dismissal ◽  
A Minor ◽  
The University ◽  
Dismissal Policy

Many higher education institutions use a policy for academic dismissal. In the Netherlands, the academic dismissal policy is such that students with fewer credits than a certain threshold after their first year, are expelled. This article employs the beta-binomial model to assess whether this method succeeds in filtering those who have potential from those who do not and what the optimal level of the threshold is. The model considers 13,234 students in three consecutive cohorts from around fifty different bachelor's degree programmes at the University of Groningen. We found that demanding 45 out of 60 credits constitutes a fair threshold for this institution. Although a strict dismissal policy has only a minor effect on cohorts, it can have a major effect on specific groups of students. The software employed here is made available.

scholarly journals Hydrocarbon fluxes above a Scots pine forest canopy: Measurements and modeling

2007 ◽  
Vol 7 (1) ◽  
pp. 2357-2388 ◽  
Author(s):  
J. Rinne ◽  
R. Taipale ◽  
T. Markkanen ◽  
T. M. Ruuskanen ◽  
H. Hellén ◽  
...  
Keyword(s):  
Scots Pine ◽  
Forest Canopy ◽  
Transport Model ◽  
Proton Transfer Reaction ◽  
Major Effect ◽  
Chemical Degradation ◽  
Research Station ◽  
Minor Effect ◽  
Emission Fluxes ◽  
A Minor

Abstract. We measured the fluxes of several hydrocarbon species above a Scots pine (Pinus sylvestris) stand using disjunct eddy covariance technique with proton transfer reaction – mass spectrometry. The measurements were conducted during four days in July at SMEAR II research station in Hyytiälä, Finland. Compounds which showed significant emission fluxes were methanol, acetaldehyde, acetone, and monoterpenes. A stochastic Lagrangian transport model with simple chemical degradation was applied to assess the sensitivity of the above canopy fluxes to chemistry. According to the model, the chemical degradation had a minor effect on the fluxes measured in this study but has a major effect on the vertical flux profiles of more reactive compounds, such as sesquiterpenes. The monoterpene fluxes followed the traditional exponential temperature dependent emission algorithm but were considerably higher than the fluxes measured before at the same site. The normalized emission potential (30°C) was 2.5 μg gdw–1 h−1 obtained using the temperature dependence coefficient of 0.09°C−1.

scholarly journals Resistance Gene Mapping for Witches' Broom Disease in Theobroma cacao L. in an F2 Population using SSR Markers and Candidate Genes

2005 ◽  
Vol 130 (3) ◽  
pp. 366-373 ◽  
Author(s):  
J. Steven Brown ◽  
R.J. Schnell ◽  
J.C. Motamayor ◽  
Uilson Lopes ◽  
David N. Kuhn ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Resistance Gene ◽  
Ssr Markers ◽  
Theobroma Cacao ◽  
Major Effect ◽  
Minor Effect ◽  
Trunk Diameter ◽  
F2 Population ◽  
Broom Disease ◽  
A Minor

A genetic linkage map was created from 146 cacao trees (Theobroma cacao), using an F2 population produced by selfing an F1 progeny of the cross Sca6 and ICS1. Simple sequence repeat (SSR) markers (170) were used principally for this map, with 12 candidate genes [eight resistance gene homologues (RGH) and four stress related WRKY genes], for a total of 182 markers. Joinmap software was used to create the map, and 10 linkage groups were clearly obtained, corresponding to the 10 known chromosomes of cacao. Our map encompassed 671.9 cM, approximately 100 cM less than most previously reported cacao maps, and 213.5 cM less than the one reported high-density map. Approximately 27% of the markers showed significant segregation distortion, mapping together in six genomic areas, four of which also showed distortion in other cacao maps. Two quantitative trait loci (QTL) for resistance to witches' broom disease were found, one producing a major effect and one a minor effect, both showing important dominance effects. One QTL for trunk diameter was found at a point 10.2 cM away from the stronger resistance gene. One RGH flanked the minor QTL for witches' broom resistance, implying possible association. QTLs mapped in F2 populations produce estimates of additive and dominance effects, not obtainable in F1 crosses. As dominance was clearly shown in the QTL found in this study, this population merits further study for evaluation of dominance effects for other traits. This F2 cacao population constitutes a useful link for genomic studies between cacao and cotton, its only widely grown agronomic relative.

Outplating of Metallic Contaminants on Silicon Wafers From Diluted Acid Solutions

1995 ◽  
Vol 386 ◽  
Author(s):  
A. L. P. Rotondaro ◽  
T. Q. Hurd ◽  
H. F. Schmidt ◽  
I. Teerlinck ◽  
M. M. Heyns ◽  
...  
Keyword(s):  
Deposition Process ◽  
Major Effect ◽  
The Other ◽  
Silicon Surfaces ◽  
Minor Effect ◽  
Acid Solutions ◽  
Thermal Oxide ◽  
Metallic Contaminants ◽  
Low Levels ◽  
A Minor

ABSTRACTThe outplating behaviour of Fe and Cu was investigated for diluted solutions of HCl and HNO3. The deposition of the metallic contaminants was found to be strongly dependent on the type of surface that is exposed to the contaminated solution. Cu deposits heavily on bare silicon surfaces, whereas only low levels of Fe deposition are observed. On the other hand, on thermal oxide surfaces, the levels of deposited Fe are consistently higher than the Cu ones. The acid used appears to have no major impact on the deposition process. The pH of the solutions has a major effect on the Cu deposition and a minor effect on the Fe case.

Effects of Osmotica Around the Roots on Water Uptake by Maize Plants

1980 ◽  
Vol 7 (1) ◽  
pp. 27 ◽  
Author(s):  
RA Nulsen ◽  
GW Thurtell
Keyword(s):  
Polyethylene Glycol ◽  
Water Potential ◽  
Nutrient Solution ◽  
Leaf Water Potential ◽  
Flow Rate ◽  
Osmotic Potential ◽  
Leaf Water ◽  
Maize Plants ◽  
The Difference ◽  
Osmotic Potentials

Nutrient solutions with osmotic potentials of -70, -190 and -380 kPa were supplied to maize plants whose roots were enclosed in a pressure chamber. The plants were stressed and then rewatered with the same nutrient solution. Sap flow rate from the detopped root system was measured at 400 kPa applied pressure. The lower was the osmotic potential of the pretreatment solution, the lower was the initial flow rate. Flow rates rapidly decreased to zero and did not recover for up to 90 min. Different responses in leaf water potential of unstressed, intact plants occurred when the nutrient solution bathing the root was replaced by either a more concentrated nutrient solution or a solution of sucrose or polyethylene glycol 6000. For nutrient solution replacement the change in leaf water potential was less than the difference in solution osmotic potentials; for sucrose the difference was greater, and for polyethylene glycol the change was equal to the osmotic potential difference. Osmotic effects observed were due to differential accumulations at different barriers in the root. The zero-flow periods seen during recovery of severely stressed plants may have been due to a decrease in the osmotic potential of the solution external to the plasmalemma of root cortical cells.

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