Short‐term responses of soils and crops to gypsum application on organic farms

This chapter critically examines the promise of organic farm volunteering programs such as WWOOF in meeting organic farmers’ need for affordable labor in Hawaii. While organic farm volunteering offers a short term coping strategy for some organic farmers, the cultural logic and rationale that propels these programs perpetuates the underlying labor problems that plague small organic farms. This chapter demonstrates the limitations of organic farm volunteering when utilized as a form of civic participation to drive economic and socio-environmental change.

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Short- and Long-Term Effects of Lime and Gypsum Applications on Acid Soils in a Water-Limited Environment: 3. Soil Solution Chemistry

Agronomy ◽

10.3390/agronomy11050826 ◽

2021 ◽

Vol 11 (5) ◽

pp. 826

Author(s):

Geoffrey C. Anderson ◽

Shahab Pathan ◽

David J. M. Hall ◽

Rajesh Sharma ◽

James Easton

Keyword(s):

Ionic Strength ◽

Soil Solution ◽

Soil Profile ◽

Soil Layer ◽

Solution Chemistry ◽

Soil Solution Chemistry ◽

Short Term ◽

Solution Ionic Strength ◽

Gypsum Application

Aluminum (Al) toxicity imposes a significant limitation to crop production in South Western Australia. This paper examines the impact of surface-applied lime and gypsum on soil solution chemistry in the short term (1 year) and the long-term (10 years) in water limited environments. In the experiments, we measured soil solution chemistry using a paste extract on soil profile samples collected to a depth of 50 cm. We then used the chemical equilibrium model MINTEQ to predict the presence and relative concentrations of Al species that are toxic to root growth (Al associated with Al3+ and AlOH2 or Toxic-Al) and less non-toxic forms of Al bound with sulfate, other hydroxide species and organic matter. A feature of the soils used in the experiment is that they have a low capacity to adsorb sulfate. In the short term, despite the low amount of rainfall (279 mm), sulfate derived from the surface gypsum application is rapidly leached into the soil profile. There was no self-liming effect, as evidenced by there being no change in soil solution pH. The application of gypsum, in the short term, increased soil solution ionic strength by 524–681% in the 0–10 cm soil layer declining to 75–109% in the 30–40 cm soil layer due to an increase in soil solution sulfate and calcium concentrations. Calcium from the gypsum application displaces Al from the exchange sites to increase soil solution Al activity in the gypsum treatments by 155–233% in the short term and by 70–196% in the long term to a depth of 40 cm. However, there was no effect on Toxic-Al due to Al sulfate precipitation. In the long term, sulfate leaching from the soil profile results in a decline in soil solution ionic strength. Application of lime results in leaching of alkalinity into the soil profile leading to a decreased Toxic-Al to a depth of 30 cm in the long term, but it did not affect Toxic-Al in the short term. Combining an application of lime with gypsum had the same impact on soil solution properties as gypsum alone in the short term and as lime alone in the long term.

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Subsoil macropore space of a transitional red-brown earth after either deep tillage, gypsum or both .I. Physical effects and short term changes

Soil Research ◽

10.1071/sr9910123 ◽

1991 ◽

Vol 29 (2) ◽

pp. 123 ◽

Cited By ~ 8

Author(s):

PS Blackwell ◽

NS Jayawardane ◽

TW Green ◽

JT Wood ◽

J Blackwell ◽

...

Keyword(s):

Pore Space ◽

Application Rate ◽

Short Term ◽

Matric Potential ◽

Deep Tillage ◽

Surface Sealing ◽

Physical Effects ◽

Considerable Loss ◽

Space Volume ◽

Gypsum Application

This research aimed to improve understanding of the processes which cause deterioration of macropore space (volume and permeability of air-filled pores at -10 kPa matric potential), as well as providing some guidelines for improving management. This paper reports the effects of amelioration treatments on soil fragment sizes and horizon-of-origin, as well as the distribution of solid gypsum in the profile immediately after deep cultivation. The macropore space of the subsoil after initial winter cropping is described from measurements on soil cores collected from the experiment. The finer fragments from slotting at low speed resulted in smaller macroporosity than in the ripped soil. Macroporosity, permeability and organization of pore space generally increase with the amount of gypsum initially mixed with the soil. In spite of the smaller volume of soil disturbed by slotting than by ripping, the reduction in runoff was similar to the ripped soil when the gypsum application rate to the slotting was twice that applied to the ripped soil. Where no gypsum was applied to the slotted soil, slumping and swelling led to considerable loss of macroporosity formed by the initial deep tillage, as well as surface sealing by dispersed clay. Hence runoff from this treatment was similar to the unameliorated soil.

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Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

Behavioral and Brain Sciences ◽

10.1017/s0140525x15000928 ◽

2016 ◽

Vol 39 ◽

Author(s):

Mary C. Potter

Keyword(s):

Working Memory ◽

Rapid Serial Visual Presentation ◽

Language Comprehension ◽

Short Term Memory ◽

Visual Presentation ◽

Long Term Memory ◽

Short Term ◽

Term Memory ◽

Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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Ultrastructural Changes of Canine Kidneys During 24-Hour Perfusion on a LI-400 Preservation System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065626 ◽

1971 ◽

Vol 29 ◽

pp. 316-317

Author(s):

M. O. Magnusson ◽

D. G. Osborne ◽

T. Shimoji ◽

W. S. Kiser ◽

W. A. Hawk

Keyword(s):

Electron Microscopy ◽

Electrolyte Solution ◽

Ultrastructural Changes ◽

Midline Incision ◽

Short Term ◽

Pentobarbital Anesthesia ◽

Pulsatile Perfusion

Short term experimental and clinical preservation of kidneys is presently best accomplished by hypothermic continuous pulsatile perfusion with cryoprecipitated and millipore filtered plasma. This study was undertaken to observe ultrastructural changes occurring during 24-hour preservation using the above mentioned method.A kidney was removed through a midline incision from healthy mongrel dogs under pentobarbital anesthesia. The kidneys were flushed immediately after removal with chilled electrolyte solution and placed on a LI-400 preservation system and perfused at 8-10°C. Serial kidney biopsies were obtained at 0-½-1-2-4-8-16 and 24 hours of preservation. All biopsies were prepared for electron microscopy. At the end of the preservation period the kidneys were autografted.

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Polychlorinated biphenyl induced hepatocyte alterations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012789x ◽

1987 ◽

Vol 45 ◽

pp. 716-717

Author(s):

D.N. Collins ◽

J.N. Turner ◽

K.O. Brosch ◽

R.F. Seegal

Keyword(s):

Lipid Droplets ◽

Wistar Rats ◽

Homovanillic Acid ◽

Polychlorinated Biphenyl ◽

Corn Oil ◽

Environmental Pollutants ◽

Short Term ◽

Pcb Congeners ◽

Urinary Levels ◽

The Brain

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).

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Acetaminophen: Macula densa hypersecretory activity by induced hepatotoxicity

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012895x ◽

1987 ◽

Vol 45 ◽

pp. 934-935

Author(s):

S.S. Poolsawat ◽

C.A. Huerta ◽

S.TY. Lae ◽

G.A. Miranda

Keyword(s):

Cell Proliferation ◽

Liver Function ◽

Chronic Inflammation ◽

Foam Cell ◽

Term Effect ◽

Short Term ◽

Drug Induced ◽

Experimental Induction ◽

Tissue Alterations ◽

Toxic Responses

Introduction. Experimental induction of altered histology by chemical toxins is of particular importance if its outcome resembles histopathological phenomena. Hepatotoxic drugs and chemicals are agents that can be converted by the liver into various metabolites which consequently evoke toxic responses. Very often, these drugs are intentionally administered to resolve an illness unrelated to liver function. Because of hepatic detoxification, the resulting metabolites are suggested to be integrated into the macromolecular processes of liver function and cause an array of cellular and tissue alterations, such as increased cytoplasmic lysis, centrilobular and localized necroses, chronic inflammation and “foam cell” proliferation of the hepatic sinusoids (1-4).Most experimentally drug-induced toxicity studies have concentrated primarily on the hepatic response, frequently overlooking other physiological phenomena which are directly related to liver function. Categorically, many studies have been short-term effect investigations which seldom have followed up the complications to other tissues and organs when the liver has failed to function normally.

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Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159412 ◽

1990 ◽

Vol 48 (3) ◽

pp. 374-375

Author(s):

D.E. Loudy ◽

J. Sprinkle-Cavallo ◽

J.T. Yarrington ◽

F.Y. Thompson ◽

J.P. Gibson

Keyword(s):

Antidepressant Drug ◽

Beagle Dogs ◽

Long Term Effects ◽

Short Term ◽

Platelet Counts ◽

Toxicological Studies ◽

Induced Aggregation ◽

Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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Short-term volume and turgor regulation in yeast

Essays in Biochemistry ◽

10.1042/bse0450147 ◽

2008 ◽

Vol 45 ◽

pp. 147-160 ◽

Cited By ~ 12

Author(s):

Jörg Schaber ◽

Edda Klipp

Keyword(s):

Dynamic Model ◽

Volume Change ◽

Volume Regulation ◽

Time Course ◽

Osmotic Shock ◽

Intracellular Concentration ◽

Short Term ◽

Hydrodynamic Property ◽

Turgor Regulation ◽

Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

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