Enhanced Root Production as a Feed-forward Response to Soil Water Deficit in Field-grown Tomatoes

1997 ◽  
Vol 24 (5) ◽  
pp. 685 ◽  
Author(s):  
J.B. Reid ◽  
A.R. Renquist
Keyword(s):  
Soil Water ◽  
Effective Means ◽  
Dry Mass ◽  
Root Production ◽  
Adaptive Responses ◽  
Feed Forward ◽  
Root Death ◽  
And Control ◽  
Practical Demonstration

Much research on the role of roots as ‘sensors’ of soil water deficits (SWD) has been with plants growing in small volumes of soil. We examined adaptive responses to SWD in processing tomatoes (Lycopersicon esculentum Mill.) growing in the field. The cv. Cannery Row was grown next to a rhizotron and trickle irrigated daily, except when water was withheld for 7 or 14 days during flowering in two deficit treatments. Rainfall was excluded. Within 7 days of withholding irrigation, there was a substantial increase in root production, particularly in the subsoil. However, predawn and midday leaf water potentials did not differ between non-irrigated and control treatments until around day 9. Even by day 14 the SWD had not affected stomatal conductances, evapotranspiration, or plant dry mass. A rapid increase in root death rate followed the re- irrigation of each deficit treatment. New root production in the non-irrigated plots appeared sufficient to maintain an adequate supply of water to the shoots. If so, this could be an even more effective means of stress avoidance than reducing leaf and stem expansion rates. Our results appear to be the first practical demonstration that root systems may play such a feed-forward role.

scholarly journals The role of health managers in community prevention and control of Corona Virus Disease 2019

2021 ◽  
Vol 235 ◽  
pp. 01052
Author(s):  
Fahu Yuan ◽  
Jiangyuan Chen ◽  
Xiaoqing Chen ◽  
Zhongqiang Chen ◽  
Ying Zhai ◽  
...  
Keyword(s):  
Rural Communities ◽  
Prevention And Control ◽  
Health Management ◽  
Virus Disease ◽  
Effective Means ◽  
Social Stability ◽  
Corona Virus ◽  
And Control ◽  
Health Managers

Since the outbreak of Corona Virus Disease 2019 (COVID-19) in December 2019, more than 26 million people have been infected. Urban and rural communities are the first line of defense for epidemic prevention and control. As an effective means of disease prevention and control at the community level, health management is of great significance in how to give full play to the professional advantages of health managers at present, and in combination with the current urgent situation of lack of specific drugs and vaccines, to maintain the health and social stability of the community population to the maximum extent. By assessing and intervening the health risk factors of COVID-19, the health manager can help the community effectively control the source of covid-19 infection, cut off the transmission route of COVID-19, effectively protect the vulnerable population in the community, and thus delay the spread and spread of COVID-19.

Effect of supplemental cover on survival of snowshoe hares and cottontail rabbits in patchy habitat

1997 ◽  
Vol 75 (9) ◽  
pp. 1357-1363 ◽  
Author(s):  
Eric W. Cox ◽  
Robert A. Garrott ◽  
John R. Cary
Keyword(s):  
Effective Means ◽  
Protective Role ◽  
Range Limits ◽  
Sylvilagus Floridanus ◽  
Fragmented Habitat ◽  
Snowshoe Hares ◽  
Patchy Habitat ◽  
Study Sites ◽  
And Control

We examined mortality patterns of sympatric snowshoe hares (Lepus americanus) and cottontail rabbits (Sylvilagus floridanus) on sites with and without brush piles to evaluate the protective role of cover in the fragmented habitat typical at the range limits of both species. Treatment sites received ≥2 oak brush piles per hectare in August and September 1994. Leporids used a minimum of 56% of created brush piles, but we failed to detect a difference in survivorship between animals occupying treatment and control sites, suggesting that brush piles may not have served as effective refugia to leporids of either species. Coyotes (Canis latrans) killed leporids in understory cover similar in mean density to that of study sites, whereas raptor kills occurred in areas with sparser understory than the average for the study sites or at coyote kills. We concluded that other methods of habitat alteration may be more effective means of increasing numbers of snowshoe hares and cottontail rabbits.

Estimating irrigation contribution to apple tree water uptake by deuterium tracing

2020 ◽  
Author(s):  
Agnese Aguzzoni ◽  
Michael Engel ◽  
Damiano Zanotelli ◽  
Francesco Comiti ◽  
Massimo Tagliavini
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Irrigation Water ◽  
Isotope Ratio ◽  
Apple Tree ◽  
Soil Depth ◽  
Capillary Rise ◽  
Soil Layer ◽  
And Control

<p>Against the background of a future decrease in water availability, there is a need to use irrigation water with higher efficiency. To improve water management, it is crucial to clarify the role of irrigation water compared to soil water and additional water sources, including groundwater, which is often neglected by most water balance models.</p><p>We used deuterium-enriched water as tracer to distinguish irrigation water from soil water and groundwater and evaluate its contribution to the apple tree water uptake. The study was conducted in an apple orchard (Malus domestica, cv. Pinova) located in a flat area of the Venosta valley (South Tyrol, Italy) characterized by shallow groundwater (about 0.9 m from the ground). Before the experiment, the soil was covered for two weeks to prevent rain and irrigation from entering the soil. In July 2019, deuterium-enriched water (40 L/m<sup>2</sup>, <em>δ</em><sup>2</sup>H = 1500 ‰) was homogenously applied to the soil in four plots. In the proximity of each irrigated plot, not-irrigated trees were present (controls). From both irrigated and control plots, soil, leaf and shoot axis samples were collected starting from 2 hours until 7 days after the irrigation. Total tree and soil water was extracted through cryogenic vacuum distillation. Soil and plant water isotope composition was measured at the IRIS (Isotope Ratio Infrared Spectroscopy) and at the IRMS (Isotope Ratio Mass Spectrometry) analyzer, respectively. Reference ET for the period was 3.3 mm day<sup>-1</sup> on average.</p><p>Soil moisture in both irrigated and control soils decreased from the surface to 0.4-0.5 m soil depth and then progressively increased again until 0.8 m depth, in line with a maximum capillary rise of approximately 0.4 m estimated by models for a silty loam soil. In the upper 0.5 m soil layer, where around 80 % of total fine roots were concentrated, labeled irrigation water represented ca. 20 % of total soil water. The labeled water firstly appeared in the shoots starting from 8 hours from the irrigation (average <em>δ</em><sup>2</sup>H = 27.4 ‰) and the deuterium concentration reached its maximum after 24-48 hours from water supply (<em>δ</em><sup>2</sup>H = 68.1 ‰). At this time, irrigation water accounted for 8 % of the shoot extracted water. Considering the average deuterium abundance of the extracted water in the first 0.5 m soil layer, where labeled irrigation water mixed with soil water, we estimated that 35-40 % of the shoot water had been absorbed from such a layer. These preliminary results highlight the complexity of soil-water-plant interactions and call for additional investigation to understand the role of the soil water present before irrigation that could be preferentially taken up by roots. Additionally, the contribution of an upward flux from groundwater should be quantified.</p><p> </p>

Morphogenesis of a New Human Herpes-Type Virus Isolate (Sasha Virus)

1973 ◽  
Vol 31 ◽  
pp. 592-593
Author(s):  
R. F. Zeigel ◽  
W. Munyon
Keyword(s):  
Virus Isolate ◽  
Calf Serum ◽  
Uranyl Acetate ◽  
Human Herpes ◽  
Human Embryonic Lung ◽  
Human Herpes Virus ◽  
Intracytoplasmic Inclusions ◽  
Hel Cells ◽  
And Control

In continuing studies on the role of viruses in biochemical transformation, Dr. Munyon has succeeded in isolating a highly infectious human herpes virus. Fluids of buccal pustular lesions from Sasha Munyon (10 mo. old) uiere introduced into monolayer sheets of human embryonic lung (HEL) cell cultures propagated in Eagles’ medium containing 5% calf serum. After 18 hours the cells exhibited a dramatic C.P.E. (intranuclear vacuoles, peripheral patching of chromatin, intracytoplasmic inclusions). Control HEL cells failed to reflect similar changes. Infected and control HEL cells were scraped from plastic flasks at 18 hrs. of incubation and centrifuged at 1200 × g for 15 min. Resultant cell packs uiere fixed in Dalton's chrome osmium, and post-fixed in aqueous uranyl acetate. Figure 1 illustrates typical hexagonal herpes-type nucleocapsids within the intranuclear virogenic regions. The nucleocapsids are approximately 100 nm in diameter. Nuclear membrane “translocation” (budding) uias observed.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

From Container to Claustrum: Projective Identification in Couples

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman
Keyword(s):  
Psychological Health ◽  
Projective Identification ◽  
The Self ◽  
The Other ◽  
Intimate Partners ◽  
And Control ◽  
The Relationship ◽  
As If

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.

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