Cumulative pattern in pH change alters response to food in the crayfish Cambarus bartoni

1994 ◽  
Vol 72 (1) ◽  
pp. 187-190 ◽  
Author(s):  
Erin Uiska ◽  
David W. Dunham ◽  
Harold H. Harvey
Keyword(s):  
Ph Change ◽  
Large Shift ◽  
Food Avoidance ◽  
Testing Period ◽  
Ph Shift ◽  
Y Maze ◽  
Acid Tolerant ◽  
Initial Tendency ◽  
Second Shift ◽  
Locomotory Response

In the relatively acid-tolerant crayfish Cambarus bartoni, locomotory response to food was tested (as delay in response, or latency) at both a circumneutral and a sublethal acid pH. Crayfish moved through a Y-maze toward a food source. Sequential tests were at pH 7.5, 4.5, and 7.5, and then again at pH 4.5 and 7.5. One group of 21 crayfish experienced a series of smaller pH shifts (7.5 to 6.5 to 5.5 to 4.5 at 5-day intervals), immediately followed by a larger pH shift (7.5 to 4.5). A second group of 20 crayfish experienced the large shift first, and then the series of smaller shifts. Both groups showed gradually decreasing latency through the first cycle, but then a large latency increase with the second shift to pH 4.5 (P < 0.005 and P < 0.03), and subsequent recovery at pH 7.5 by the first group (P < 0.006) but not the second (P < 0.32). This effect would seem to be due to the previous pH shift, which apparently exceeded their tolerance within our 45-day testing period. An initial tendency to approach the food (P < 0.01 and P < 0.12) became food avoidance (P < 0.01) and (or) no preference during either the first or second exposure to acidic pH.

Low pH alters response to food in the crayfish Cambarus bartoni

1992 ◽  
Vol 70 (12) ◽  
pp. 2416-2420 ◽  
Author(s):  
Vanessa Allison ◽  
David W. Dunham ◽  
Harold H. Harvey
Keyword(s):  
Low Ph ◽  
The Other ◽  
Food Cues ◽  
Central Processing ◽  
Acid Ph ◽  
Y Maze ◽  
Initial Control ◽  
Acid Tolerant ◽  
Locomotory Response

In a relatively acid-tolerant crayfish, Cambarus bartoni, locomotory response to food, and associated antennular flicking, were tested at both a circumneutral and a sublethal acid pH. Crayfish were run through a Y maze at pH 7.5, 4.5, and again at 7.5. One arm of the Y maze contained food; the other did not. The time to complete the maze at pH 4.5 increased significantly compared with the time taken at pH 7.5 (P < 0.001). Once pH was restored to 7.5, the time to complete the maze was greater than the initial control at pH 7.5 (P < 0.001) but less than pH 4.5 (P < 0.05). At pH 7.5, 73% of the crayfish chose the food arm; at pH 4.5, 33% chose the food arm; and when pH was returned to 7.5, 46% chose the food arm. Antennular flicking frequency was greatest at pH 7.5 and significantly less at 4.0 (P < 0.0001). Once pH was restored to 7.5, flicking rates were significantly lower than those in the first trial at pH 7.5 (P < 0.01), but significantly greater than those at pH 4.0. Decreased antennular flicking and possible avoidance of food at a sublethal pH (4.0) imply that either chemoreception of food cues or normal central processing of chemical input is seriously impaired.

Neutralization and Fertilization of Acidified Lakes Near Sudbury, Ontario

1976 ◽  
Vol 11 (1) ◽  
pp. 93-100 ◽  
Author(s):  
W. Scheider ◽  
P.J. Dillon
Keyword(s):  
Standing Stock ◽  
Reproductive Rate ◽  
Taxonomic Composition ◽  
Plate Count ◽  
Buffer System ◽  
Ph Change ◽  
Experimental Lakes Area ◽  
Metal Levels ◽  
Acid Tolerant ◽  
Lake Waters

Abstract Investigations into the consequences of neutralizing acidic lakes, establishing buffer systems and reducing heavy metal levels by additions of Ca(OH)2 and CaCO3 are described. Two pairs of lakes in the immediate vicinity of Sudbury, Ontario, were chosen for study commencing in June 1973. Prior to treatment, all lakes could be described as soft (hardness 21–47 mg/l as CaCO3), poorly buffered (alkalinity 0.4–2.6 mg/l as CaCO3) with low pH values (4.4–4.5). Sulphate was the dominant ionic constituent in the lakes (26–55 mg/l). Copper and nickel levels were among the highest recorded in the Sudbury region. The low HPC: aciduric ratio (total heterotrophic plate count: acid-tolerant plate count) demonstrates the atypical bacterial composition of the lake waters. The standing stocks of phytoplankton, Zooplankton and zoobenthos were somewhat lower and taxonomic composition abnormal as compared to “typical” oligotrophic lakes on the Canadian Shield as studied in the Experimental Lakes Area of Ontario. The two downstream lakes were treated in the fall of 1973, one with Ca(OH)2 only; the other with a combination of Ca(OH)2 and CaCO3. The upstream lakes were monitored as controls. Both treated lakes showed an increase in pH to about 7.0 and reductions in total Cu, Ni and Zn levels of 13–83%. The combination treatment proved superior in that a more stable buffer system was established and pH remained near neutrality for the duration of the study. The rapid pH change (three units in a matter of weeks) caused an initial decline in the standing stock of phytoplankton, Zooplankton and zoobenthos. The bacteria were the first to show a positive response to the altered water chemistry; the HPC: aciduric ratio increasing immediately following treatment. The phytoplanktonic standing stock increased and the taxonomic composition changed the summer following treatment. Numbers of Zooplankton and zoobenthos did not increase the year following treatment, probably because of the relative difficulty in recolonization and their slower reproductive rate. In an effort to increase biological standing stock, Middle Lake was fertilized with phosphorus 1½ years after neutralization. Numbers of phytoplankton and Zooplankton increased and taxonomic composition shifted.

Validating a food avoidance assessment for children with food selectivity.

2018 ◽  
Vol 23 (2) ◽  
pp. 89-105 ◽  
Author(s):  
Katherine R. Kunkel ◽  
Alison M. Kozlowski ◽  
Tessa Taylor ◽  
Melissa L. González
Keyword(s):  
Food Selectivity ◽  
Food Avoidance

Food Avoidance in Hungry Monkeys

1973 ◽  
Author(s):  
Fogle C. Clark ◽  
James B. Smith
Keyword(s):  
Food Avoidance

Cancer Patients Food Avoidance Behaviors Scale

2019 ◽  
Author(s):  
Tony K. C. Yung ◽  
Jean H. Kim ◽  
Sing-Fai Leung ◽  
Rebecca M. W. Yeung ◽  
Annette N. Y. Poon ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Food Avoidance ◽  
Avoidance Behaviors

Institutional Historical Memory and History in Post-Soviet Belarus

2020 ◽  
Vol 9 (1) ◽  
pp. 51-73
Author(s):  
Alena Marková
Keyword(s):  
Historical Memory ◽  
Typical Feature ◽  
Historical Narrative ◽  
Soviet Period ◽  
National History ◽  
Nationality Policy ◽  
Second Shift ◽  
Characteristic Features ◽  
The Government ◽  
Clear Shift

Abstract Belarusian institutional historical memory (as defined by Richard Ned Lebow) and the interpretation of Belarusian national history have experienced radical shifts in the past several decades. The first shift (1990–1994) was characterized by radical rejection of the interpretational and methodological patterns of the Soviet period, resulting in the creation of a new concept of Belarusian national history and historical narrative. The second shift in the existing historical narrative and institutional memory followed rapidly. It came with the transformation from a parliamentary republic into a parliamentary-presidential (1994) and then presidential republic (1996). The second wave demonstrated a clear shift towards a methodological, theoretical approach and terminological framework typical of the historiography of the Soviet period. These changes were in response to the growing demands for ideological control of institutionalized historical research supported by the government in the same decade. One of the characteristic features of recent Belarusian state-sponsored historiography (Lyč, Chigrinov, Marcuĺ, Novik and others) is the linking of post-Soviet national initiatives to Nazi occupation and collaboration in World War II. Another typical feature is simplifying historical explanations and often using undisguised pejorative terminology. The last shift in institutional historical memory also resulted in further re-interpretations of many symbolic centres and milestones of Belarusian history (for example, the period of the first years of post-Soviet independence, the introduction of new national symbols (Pahonia coat of arms and white-red-white flag) and the interwar nationality policy of Belarusization of the 1920s.)

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