scholarly journals Cell Cycle, Division Rate, and Feeding of the Heterotroph Phalacroma rotundatum in a Chilean Fjord

2019 ◽  
Vol 7 (10) ◽  
pp. 451
Author(s):  
Patricio A. Díaz ◽  
Iván Pérez-Santos ◽  
Gonzalo Álvarez ◽  
Michael Araya ◽  
Francisco Álvarez ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Austral Summer ◽  
Field Studies ◽  
Local Characteristic ◽  
Reference List ◽  
Shellfish Poisoning ◽  
Division Rate ◽  
Bottom Waters ◽  
Harmful Microalgae ◽  
And Behavior

Phalacroma rotundatum is a rare cosmopolitan heterotrophic dinoflagellate. This species, included in the IOC-UNESCO Taxonomic Reference List of Harmful Microalgae, may be a diarrhetic shellfish poisoning (DSP) toxin vector, but little is known about its ecophysiology and behavior. A vertical net haul collected during the austral summer of 2018 in Reloncaví Sound (Chilean Patagonia) revealed an unusually abundant population of P. rotundatum and prompted intensive 24 h sampling on 16–17 January to study the cell cycle and feeding behavior of this species. Hydrographic measurements from a buoy revealed the local characteristic estuarine circulation, with a brackish surface layer (salinity 26–28) separated from saltier, colder bottom waters by a pycnocline at a depth modulated by the tidal regime. A high proportion of P. rotundatum cells were packed with digestive vacuoles (peak of 70% at 14:00), and phased cell division (µ = 0.46 d−1) occurred 3 h after sunrise. The division time (TD) was 2 h. This is the first cell cycle study of P. rotundatum. The results here disagree with those of previous field studies that considered asynchronous division in some Dinophysis species to be related to heterotrophic feeding. They also question the very specific prey requirements, Tiarina fusus, reported for P. rotundatum in northern Europe.

Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Habitat Preference ◽  
Additional Data ◽  
Near East ◽  
Field Studies ◽  
Subspecies Level ◽  
Limited Gene Flow ◽  
Study Sites ◽  
And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

scholarly journals Scheduling Chemotherapy: Catch 22 between Cell Kill and Resistance Evolution

2000 ◽  
Vol 2 (3) ◽  
pp. 215-232 ◽  
Author(s):  
Shea N. Gardner
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Drug Exposure ◽  
Drug Application ◽  
Growth Fraction ◽  
Cycle Phase ◽  
Response Curves ◽  
Division Rate ◽  
Drug Concentrations ◽  
Cns Drugs

Dose response curves show that prolonged drug exposure at a low concentration may kill more cells than short exposures at higher drug concentrations, particularly for cell cycle phase specific drugs. Applying drugs at low concentrations for prolonged periods, however, allows cells with partial resistance to evolve higher levels of resistance through stepwise processes such as gene amplification. Models are developed for cell cycle specific (CS) and cell cycle nonspecific (CNS) drugs to identify the schedule of drug application that balances this tradeoff.The models predict that a CS drug may be applied most effectively by splitting the cumulative dose into many (>40) fractions applied by long-term chemotherapy, while CNS drugs may be better applied in fewer than 10 fractions applied over a shorter term. The model suggests that administering each fraction by continuous infusion may be more effective than giving the drug as a bolus, whether the drug is CS or CNS. In addition, tumors with a low growth fraction or slow rate of cell division are predicted to be controlled more easily with CNS drugs, while those with a high proliferative fraction or fast cell division rate may respond better to CS drugs.

Cell proliferation in the developing wing-bud of normal and talpid3 mutant chick embryos

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 589-607
Author(s):  
D. A. Ede ◽  
O. P. Flint ◽  
P. Teague
Keyword(s):  
Cell Cycle ◽  
Early Stage ◽  
Mitotic Rate ◽  
Mitotic Division ◽  
Chick Embryos ◽  
Division Rate ◽  
Cell Cycle Time ◽  
Continuous Sampling ◽  
Wing Bud ◽  
Marked Drop

Previous measurements on mitotic division rate or cell cycle time have been made on samples from a few discrete limb regions or by continuous sampling, but only down a unidimensional limb axis, disregarding morphological discontinuities such as the presence or absence of cartilage. This study presents a new analysis on normal and talpid3 mutant chick embryos, measuring mitotic rate and also cell density through the central proximo-distal axis and at the limb periphery, taking into account the development of cartilage regions. Differentiation of cartilage is correlated with a marked drop in mitotic rate, accounting for a proximo-distal gradient of mitosis in central counts which was not observed at the limb periphery. Talpid3 limbs at an early stage show a central mitotic gradient, but the reverse of that observed in normal limbs.

scholarly journals How Does Consumers’ Local or Global Identity Influence Price–Perceived Quality Associations? The Role of Perceived Quality Variance

2019 ◽  
Vol 83 (3) ◽  
pp. 145-162 ◽  
Author(s):  
Zhiyong Yang ◽  
Sijie Sun ◽  
Ashok K. Lalwani ◽  
Narayan Janakiraman
Keyword(s):  
Secondary Data ◽  
Field Studies ◽  
Perceived Quality ◽  
Local Identity ◽  
Global Identity ◽  
Natural Boundaries ◽  
Price Perceptions ◽  
And Behavior ◽  
The Relationship

Globalization has substantially influenced the world economy. However, managers have a limited understanding of how local–global identity influences consumers’ price perceptions and behavior. In this research, the authors propose that consumers’ local (vs. global) identity leads to a greater tendency to make price–perceived quality (PPQ) associations. Perceived quality variance among comparison brands is a key mechanism underlying these effects. Two field studies (Studies 1 and 7), seven experiments (Studies 2–6, 9, and 10), and a systematic review of secondary data (Study 8) provide converging and robust evidence for the effect of local–global identity on PPQ. Consistent with the perceived quality variance account, when quality differences among the brands are made salient, PPQ associations of consumers high in global (but not local) identity significantly increase, compared with baseline conditions. However, when perceived quality similarities are made salient, PPQ associations of consumers high in local (but not global) identity significantly decrease. Product type and distribution of customer ratings represent natural boundaries for the relationship between local–global identity and PPQ. The authors conclude with the implications for managers’ targeting endeavors. We also provide specific tools that marketers can use in ads and point-of-purchase materials to encourage or discourage consumers in making PPQ associations.

scholarly journals Field Studies of Nutrition and Behavior

Science ◽  
1969 ◽  
Vol 166 (3910) ◽  
pp. 1312-1313
Author(s):  
A. P. Vayda ◽  
C. Lowman-Vayda
Keyword(s):  
Field Studies ◽  
And Behavior

scholarly journals The p110 Isoform of the CDP/Cux Transcription Factor Accelerates Entry into S Phase

2006 ◽  
Vol 26 (6) ◽  
pp. 2441-2455 ◽  
Author(s):  
Laurent Sansregret ◽  
Brigitte Goulet ◽  
Ryoko Harada ◽  
Brian Wilson ◽  
Lam Leduy ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Cell Cycle Progression ◽  
S Phase ◽  
Proteolytic Processing ◽  
Experimental Conditions ◽  
Division Rate ◽  
Cycle Progression ◽  
Processing Event

ABSTRACT The CDP/Cux transcription factor was previously found to acquire distinct DNA binding and transcriptional properties following a proteolytic processing event that takes place at the G1/S transition of the cell cycle. In the present study, we have investigated the role of the CDP/Cux processed isoform, p110, in cell cycle progression. Populations of cells stably expressing p110 CDP/Cux displayed a faster division rate and reached higher saturation density than control cells carrying the empty vector. p110 CDP/Cux cells reached the next S phase faster than control cells under various experimental conditions: following cell synchronization in G0 by growth factor deprivation, synchronization in S phase by double thymidine block treatment, or enrichment in G2 by centrifugal elutriation. In each case, duration of the G1 phase was shortened by 2 to 4 h. Gene inactivation confirmed the role of CDP/Cux as an accelerator of cell cycle progression, since mouse embryo fibroblasts obtained from Cutl1z/z mutant mice displayed a longer G1 phase and proliferated more slowly than their wild-type counterparts. The delay to enter S phase persisted following immortalization by the 3T3 protocol and transformation with H-RasV12. Moreover, CDP/Cux inactivation hindered both the formation of foci on a monolayer and tumor growth in mice. At the molecular level, expression of both cyclin E2 and A2 was increased in the presence of p110 CDP/Cux and decreased in its absence. Overall, these results establish that p110 CDP/Cux functions as a cell cycle regulator that accelerates entry into S phase.

Attribution and behavior: Two field studies.

1975 ◽  
Vol 32 (1) ◽  
pp. 185-190 ◽  
Author(s):  
Mark G. McGee ◽  
Mark Snyder
Keyword(s):  
Field Studies ◽  
And Behavior

TECHNIQUES FOR STUDYING THE BEHAVIOR AND ECOLOGY OF THE EUROPEAN EARWIG, FORFICULA AURICULARIA (DERMAPTERA: FORFICULIDAE)

1974 ◽  
Vol 106 (8) ◽  
pp. 881-888 ◽  
Author(s):  
Robert J. Lamb ◽  
W. G. Wellington
Keyword(s):  
Experimental Animal ◽  
Population Studies ◽  
Field Studies ◽  
Artificial Nest ◽  
Forficula Auricularia ◽  
Insect Ecology ◽  
And Behavior ◽  
European Earwig

AbstractThe European earwig is an excellent experimental animal for many laboratory and field studies of insect ecology and behavior, but special rearing, marking, and trapping techniques are required to exploit the insects’ potential fully. This paper describes an artificial nest and associated techniques which reduce rearing mortality below 10%. Methods of studying events in natural nests, and of capturing and marking individuals for population studies, also are described.

scholarly journals Impact of Global Transcriptional Silencing on Cell Cycle Regulation and Chromosome Segregation in Early Mammalian Embryos

2021 ◽  
Vol 22 (16) ◽  
pp. 9073
Author(s):  
Martin Anger ◽  
Lenka Radonova ◽  
Adela Horakova ◽  
Diana Sekach ◽  
Marketa Charousova
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Significant Proportion ◽  
Transcriptional Silencing ◽  
Early Embryo ◽  
Global Changes ◽  
Embryonic Genome ◽  
Mammalian Embryos ◽  
A Cell ◽  
And Behavior

The onset of an early development is, in mammals, characterized by profound changes of multiple aspects of cellular morphology and behavior. These are including, but not limited to, fertilization and the merging of parental genomes with a subsequent transition from the meiotic into the mitotic cycle, followed by global changes of chromatin epigenetic modifications, a gradual decrease in cell size and the initiation of gene expression from the newly formed embryonic genome. Some of these important, and sometimes also dramatic, changes are executed within the period during which the gene transcription is globally silenced or not progressed, and the regulation of most cellular activities, including those mentioned above, relies on controlled translation. It is known that the blastomeres within an early embryo are prone to chromosome segregation errors, which might, when affecting a significant proportion of a cell within the embryo, compromise its further development. In this review, we discuss how the absence of transcription affects the transition from the oocyte to the embryo and what impact global transcriptional silencing might have on the basic cell cycle and chromosome segregation controlling mechanisms.

scholarly journals The Effectiveness of Tri Hita Karana Based Traditional Village Management in Covid-19 Prevention at Bali

2021 ◽  
Vol 7 (1) ◽  
pp. 56-80
Author(s):  
Ni Putu Mirna Sari ◽  
◽  
Bimo Dwi Nur Romadhon Sukadi ◽  
Putu Nomy Yasintha ◽  
◽  
...  
Keyword(s):  
Financial Management ◽  
Research Method ◽  
Field Studies ◽  
The Self ◽  
Regional Government ◽  
Fund Management ◽  
Activity Program ◽  
Economic Slowdown ◽  
The Government ◽  
And Behavior

Traditional villages are original autonomous villages that control the self-government wheels within that are still alive and their position is recognized in the government system of the Indonesian Republic. The Covid-19 pandemic that is currently happening is causing an economic slowdown and a decline in public health. Bali Regional Government issued a policy in Bali Governor Regulation Number 15 of 2020 regarding the Policy for the Acceleration of Handling Covid-19 in the Province of Bali by reallocating a Traditional Village Fund of Rp. 300,000,000.00 for the response to Covid-19 by involving the soldiers and manners of the Traditional Village. The effectiveness of the Traditional Village Fund management is based on local wisdom, where the principles of Tri Hita Karana (Parahyangan, Pawongan, and Palemahan) as a philosophical foundation that are held in carrying out every activity, program, and policy are the focus of this research. This research uses a qualitative research method. Data were taken directly from field studies and literature studies. The implementation of Tri Hita Karana provides a new color in financial management in Indonesia. Technical implementation, reporting, prosecution of alleged fraud, and consultative accountability manner and rich in local wisdom values upheld by Bendesa, Prajuru Desa Adat, and Krama Desa positively impact influencing the community mindset and behavior in complying with existing regulations or policies set. However, it cannot be denied that there are still contradictions between Bali’s traditional village governance in generating accountable and transparent management of funds.

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