Eat and run? The hunger/satiation hypothesis in vertical migration: history, evidence and consequences

2003 ◽  
Vol 78 (1) ◽  
pp. 1-79 ◽  
Author(s):  
SIFFORD PEARRE
Keyword(s):  
Vertical Migration ◽  
Migration History ◽  
Satiation Hypothesis

Emergency Urbanism in Sabra, Beirut

2019 ◽  
Vol 1 (2) ◽  
pp. 171-193 ◽  
Author(s):  
Are John Knudsen
Keyword(s):  
Civil War ◽  
Affordable Housing ◽  
Vertical Migration ◽  
Migration History ◽  
History Of ◽  
Displaced People ◽  
And Control

Since the mid-1980s, generations of displaced people have sought refuge in the ramshackle buildings that were once the Gaza-Ramallah Hospital, a multi-story hospital complex built by the Palestinian Liberation Organization (plo). Damaged during the civil war, today the buildings blend in with the run-down Sabra-Shatila neighbourhood in Beirut’s “misery belt.” This paper charts the buildings’ history and main characters: the lodgers, landlords, and gatekeepers who respectively lease, rent, and control the dilapidated buildings’ dark corridors, cramped flats, and garbage-strewn stairways. The multi-story buildings are examples of emergency urbanism whereby displaced people seek refuge in cities, and their story can be read as a vertical migration history of people escaping conflict, displacement, and destitution. Examining the buildings as archives of spatial and political histories provides a genealogy of displacement and emplacement that can inform the study of emergency urbanism and point to solutions in cities for refugees lacking access to affordable housing.

scholarly journals State of Satiation Partially Regulates the Dynamics of Vertical Migration

2021 ◽  
Vol 8 ◽  
Author(s):  
Ryan P. Bos ◽  
Tracey T. Sutton ◽  
Tamara M. Frank
Keyword(s):  
Predation Risk ◽  
Fish Species ◽  
Vertical Migration ◽  
Behavioral Plasticity ◽  
Species Assemblage ◽  
Stomach Fullness ◽  
Ocean Acoustics ◽  
Deep Waters ◽  
Nocturnal Feeding ◽  
Satiation Hypothesis

Vertical migrations into shallower waters at night are beneficial for migrators as they reduce predation risk and allow migrators to encounter a higher density of prey. Nevertheless, ocean acoustics data and trawl data have shown that a portion of some vertically migrating populations remain at depth and do not migrate. One hypothesis for this phenomenon is the Hunger-Satiation hypothesis, which in part states that the non-migrating portion of the migrating species-assemblage refrains from migrating if they have full or partially full stomachs from daytime or nocturnal feeding. However, stomach fullness of the non-migrating subpopulation compared to the migrating portion has rarely been studied, due to the difficulty in obtaining sufficient samples. The stomach fullness levels of numerically abundant crustacean and fish species with well-known depth distributions were quantified in the present study. Animals were captured during night trawls from discrete-depth intervals between 0 and 1,500 m. Stomach fullness indices were assigned from 0 to 5 and compared between migratory taxa caught in shallow and deep waters. Data from the crustaceansAcanthephyra purpurea, Gardinerosergia splendens, Plesionika richardi, andSystellaspsis debilis, as well as the fishesLampanyctus alatus, Lepidophanes guentheri, andNotolychnus valdiviae, provided support for the Hunger-Satiation hypothesis, while data from the crustaceansGennadas capensisandGennadas valensand the fishBenthosema suborbitaledid not. These findings suggest that stomach vacancy may be just one of several factors regulating the dynamics of vertical migration in those species whose behavioral plasticity suggests daily “choices” in whether or not to vertically migrate.

scholarly journals Response of Vertical Migration and Leaching of Nitrogen in Percolation Water of Paddy Fields under Water-Saving Irrigation and Straw Return Conditions

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 868 ◽  
Author(s):  
Chengxin Zheng ◽  
Zhanyu Zhang ◽  
Yunyu Wu ◽  
Richwell Mwiya
Keyword(s):  
Vertical Migration ◽  
Growth Stage ◽  
Nitrogen Leaching ◽  
Water Saving ◽  
Paddy Fields ◽  
N Leaching ◽  
Leaching Losses ◽  
Leaching Loss ◽  
Straw Return ◽  
Percolation Water

The use of water-saving irrigation techniques has been encouraged in rice fields in response to irrigation water scarcity. Straw return is an important means of straw reuse. However, the environmental impact of this technology, e.g., nitrogen leaching loss, must be further explored. A two-year (2017–2018) experiment was conducted to investigate the vertical migration and leaching of nitrogen in paddy fields under water-saving and straw return conditions. Treatments included traditional flood irrigation (FI) and two water-saving irrigation regimes: rain-catching and controlled irrigation (RC-CI) and drought planting with straw mulching (DP-SM). RC-CI and DP-SM both significantly decreased the irrigation input compared with FI. RC-CI increased the rice yield by 8.23%~12.26%, while DP-SM decreased it by 8.98%~15.24% compared with FI. NH4+-N was the main form of the nitrogen leaching loss in percolation water, occupying 49.06%~50.97% of TN leaching losses. The NH4+-N and TN concentration showed a decreasing trend from top to bottom in soil water of 0~54 cm depth, while the concentration of NO3−-N presented the opposite behavior. The TN and NH4+-N concentrations in percolation water of RC-CI during most of the rice growth stage were the highest among treatments in both years, and DP-SM showed a trend of decreasing TN and NH4+-N concentrations. The NO3−-N concentrations in percolation water showed a regular pattern of DP-SM > RC-CI > FI during most of the rice growth stage. RC-CI and DP-SM remarkably reduced the amount of N leaching losses compared to FI as a result of the significant decrease of percolation water volumes. The tillering and jointing-booting stages were the two critical periods of N leaching (accounted for 74.85%~86.26% of N leaching losses). Great promotion potential of RC-CI and DP-SM exists in the lower reaches of the Yangtze River, China, and DP-SM needs to be further optimized.

Diel, lunar and seasonal vertical migration in the deep western Gulf of Mexico evidenced from a long-term data series of acoustic backscatter

2021 ◽  
pp. 102562
Author(s):  
Laura Ursella ◽  
Sara Pensieri ◽  
Enric Pallàs-Sanz ◽  
Sharon Z. Herzka ◽  
Roberto Bozzano ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Vertical Migration ◽  
Acoustic Backscatter ◽  
Data Series ◽  
Term Data

Diel vertical migration of mesozooplankton in the northern Yellow Sea

2021 ◽  
Author(s):  
Ruping Ge ◽  
Hongju Chen ◽  
Guangxing Liu ◽  
Yanzhong Zhu ◽  
Qiang Jiang
Keyword(s):  
Vertical Migration ◽  
Yellow Sea ◽  
Diel Vertical Migration ◽  
Northern Yellow Sea

scholarly journals Role of large-scale advection and small-scale turbulence on vertical migration of gyrotactic swimmers

2019 ◽  
Vol 4 (12) ◽  
Author(s):  
C. Marchioli ◽  
H. Bhatia ◽  
G. Sardina ◽  
L. Brandt ◽  
A. Soldati
Keyword(s):  
Vertical Migration ◽  
Large Scale ◽  
Small Scale ◽  
Scale Turbulence

scholarly journals A Circular Chloroplast Genome of Fagus sylvatica Reveals High Conservation between Two Individuals from Germany and One Individual from Poland and an Alternate Direction of the Small Single-Copy Region

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Bagdevi Mishra ◽  
Bartosz Ulaszewski ◽  
Sebastian Ploch ◽  
Jaroslaw Burczyk ◽  
Marco Thines
Keyword(s):  
Chloroplast Genome ◽  
Fagus Sylvatica ◽  
Pollen Dispersal ◽  
European Beech ◽  
Single Copy ◽  
Migration History ◽  
Chloroplast Genomes ◽  
Long Read ◽  
The Individual ◽  
Small Single Copy

Chloroplasts are difficult to assemble because of the presence of large inverted repeats. At the same time, correct assemblies are important, as chloroplast loci are frequently used for biogeography and population genetics studies. In an attempt to elucidate the orientation of the single-copy regions and to find suitable loci for chloroplast single nucleotide polymorphism (SNP)-based studies, circular chloroplast sequences for the ultra-centenary reference individual of European Beech (Fagus sylvatica), Bhaga, and an additional Polish individual (named Jamy) was obtained based on hybrid assemblies. The chloroplast genome of Bhaga was 158,458 bp, and that of Jamy was 158,462 bp long. Using long-read mapping on the configuration inferred in this study and the one suggested in a previous study, we found an inverted orientation of the small single-copy region. The chloroplast genome of Bhaga and of the individual from Poland both have only two mismatches as well as three and two indels as compared to the previously published genome, respectively. The low divergence suggests low seed dispersal but high pollen dispersal. However, once chloroplast genomes become available from Pleistocene refugia, where a high degree of variation has been reported, they might prove useful for tracing the migration history of Fagus sylvatica in the Holocene.

A laboratory study of vertical migration

1955 ◽  
Vol 144 (916) ◽  
pp. 329-354 ◽  
Keyword(s):  
Light Intensity ◽  
Vertical Migration ◽  
Time Course ◽  
Tap Water ◽  
Low Light ◽  
Overhead Light ◽  
Light Intensities ◽  
Orientation Response ◽  
Reduced Light ◽  
Characteristic Maximum

In a tank filled with a suspension of indian ink in tap water, a population of Daphnia magna will undergo a complete cycle of vertical migration when an overhead light source is cycli­cally varied in intensity. A ‘dawn rise’ to the surface at low intensity is followed by the descent of the animals to a characteristic maximum depth. The animals rise to the surface again as the light decreases, and finally show a typical midnight sinking. The light intensities at the level of the animals in this experiment are of the same order as those which have been reported in field observations; the time course of the movement also repeats the natural conditions in the field. The process is independent of the duration of the cycle and is related only to the variation in overhead light intensity. At low light intensity the movement of the animal is determined solely by positive photo-kinesis; the dawn rise is a manifestation of this, and is independent of the direction of the light. At high light intensities there is an orientation response which is superimposed upon an alternating positive (photokinetic) phase and a negative phase during which movement is inhibited. The fully oriented animal shows a special type of positive and negative phototaxis, moving towards the light at reduced light intensities and away from it when the light intensity is increased. In this condition it follows a zone of optimum light intensity with some exactness. Experiments show that an animal in this fully oriented condition will respond to the slow changes of intensity characteristic of the diurnal cycle, while being little affected by tran­sient changes of considerable magnitude.

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