scholarly journals Multiple nest entrances alter foraging and information transfer in ants

2020 ◽  
Vol 7 (2) ◽  
pp. 191330 ◽  
Author(s):  
Marine Lehue ◽  
Bertrand Collignon ◽  
Claire Detrain

The ecological success of ants relies on their ability to discover and collectively exploit available resources. In this process, the nest entrances are key locations at which foragers transfer food and information about the surrounding environment. We assume that the number of nest entrances regulates social exchanges between foragers and inner-nest workers, and hence influences the foraging efficiency of the whole colony. Here, we compared the foraging responses of Myrmica rubra colonies settled in either one-entrance or two-entrance nests. The total outflows of workers exploiting a sucrose food source were similar regardless of the number of nest entrances. However, in the two-entrance nests, the launching of recruitment was delayed, a pheromone trail was less likely to emerge between the nest and the food source, and recruits were less likely to reach the food target. As a result, an additional entrance through which information could transit decreased the efficiency of social foraging and ultimately led to a lower amount of retrieved food. Our study confirms the key-role of nest entrances in the transfer of information from foragers to potential recruits. The influence of the number of entrances on the emergence of a collective trail also highlights the spatially extended impact of the nest architecture that can shape foraging patterns outside the nest.

2020 ◽  
Vol 4 (1) ◽  
pp. 1-12
Author(s):  
Elizabeth C. Lopardo ◽  
Clare M. Ryan

Four dams on the lower Snake River in Washington State generate hydropower and allow for regional agriculture and barge shipping to Portland OR. However, the dams impede the migration of local salmon populations (Oncorhynchus spp.), which are in steep decline, and drastically impact the populations of salmon and orca whales, for whom salmon are a primary food source. For years, environmental groups have argued for breaching the dams; other interests counter that the dams are too critical to the economy of the region to lose; and federal agencies assert that the dams can remain and salmon populations will recover with mitigation techniques. Scientific and economic analyses, litigation, and elected officials’ efforts have not been able to move the issue towards a solution. Readers will examine the interests of primary actors in the issue, how they influence the policy process, the role of scientific and economic analyses, and possible approaches for resolving the issue.


2020 ◽  
Vol 42 (3) ◽  
pp. 355-368
Author(s):  
YEVGENIY ALEKSANDROV

The aim of the article is to recall the fi steps of comprehension by the scientific community of possibilities of a newly born means of the reality reflection. The means was initially oriented for obtaining reliable information and supposing a delayed reaction of the spectator in the process of communication. Recollection and understanding become more important under the distance education condition. Pre-revolutionary Russia lived anticipating changes, and the filmmaking was considered by the society as one of those progressive phenomena evidencing the coming of a new age. The scientists’ activity during the development of scientific fi in pre-revolutionary Russia was long hushed up and wasn’t considered as forming a basis for the future system of educational audio-visual communication. In this process there participated striking, creative personalities, mostly belonged to the community of Imperial Moscow University, which activity was during the age of changes. The significant contribution of pleiad of eminent scientists’ activity to the new direction formation was a reason to unify in one paper both their whole professional life data and information about their time-limited period of scientific fi In the future a more profound study of their achievements are considered to be promising. In the introduction the anterior period of the Russian fi appearance, where the scientific and education community of Russia was exploring the possibilities of a new means of information transfer for education purposes, is considered. Two main units are dedicated to the role of scientists in the development of scientific filmmaking for research and popularization of biomedical and physical problems.


2011 ◽  
Vol 51 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Halina Kucharczyk ◽  
Paweł Bereś ◽  
Zbigniew Dąbrowski

The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea MaysL.) in Southeastern PolandThrips species composition and seasonal abundance was studied on maize crops during two seasons (2006-2007), in southeastern Poland. Altogether 21 species have been identified, among themFrankliniella tenuicornis(Uzel 1895) andHaplothrips aculeatus(Fabricius 1803) which are a graminicolous species and were eudominants, comprising 96.8% in 2006 and 82.0% in 2007 of all collected specimens. Other species occurred only in low numbers. The frequent and numerous presence ofF. tenuicornisspecies in their immature stages in the samples, confirmed the role of the maize plant as the host.H. aculeatusprobably chose maize as a food source and substitute plant for breeding.


2015 ◽  
Vol 60 (8) ◽  
pp. 12-24
Author(s):  
Renata Bielak ◽  
Ewa Czumaj

The mission of official statistics is to provide credible, reliable, independent and high-quality information on the state and changes in society, the economy and the environment, meet the needs of domestic and foreign users. Fulfillment of this obligation is reflected in the work of the current official statistics and in development activities. Monitoring of the socio-economic development requires continuous adaptation of statistics to the changing reality and the description of the phenomena and processes. The role of official statistics in the modern world goes far beyond the implementation of the research. Measuring sustainable development and information support for development policy are tangible examples of the undertaken challenges. The form and manner of data presentation have increasing importance for the effective transfer of information. To answer the need to improve communication with users, the CSO is implementing new systems of information share. The article describes, among others, ”Strateg” and ”Knowledge Databases”.


1991 ◽  
Vol 260 (3) ◽  
pp. H877-H883 ◽  
Author(s):  
M. R. Prasad ◽  
L. M. Popescu ◽  
I. I. Moraru ◽  
X. K. Liu ◽  
S. Maity ◽  
...  

We investigated the role of phospholipase A2 (PLA2) and phospholipase C (PLC) in myocardial phosholipid degradation and cellular injury during reperfusion of ischemic myocardium. For this purpose, isolated rat hearts were perfused with isotopic arachidonic acid to label its membrane phospholipids. Hearts preperfused with antiphospholipase A2 (anti-PLA2) retained a significantly higher amount of radiolabel in phosphatidylcholine and phosphatidylinositol and a corresponding lower amount of radiolabel in lysophosphatidylcholine and nonesterified fatty acids (P less than 0.05) after 30 min of reperfusion following 30 min of normothermic global ischemia compared with hearts preperfused with nonimmune immunoglobulin G. In similar experiments, antiphospholipase C (anti-PLC)-treated hearts were associated with significantly (P less than 0.05) higher radiolabel in all phospholipids and lower radiolabel in diacyglycerol compared with nonimmune immunoglobulin G-treated hearts. Measurement of phospholipase activity in subcellular organelles of these hearts showed decreased PLA2 activity in cytosol, mitochondria, and microsomes of anti-PLA2-treated hearts and decreased PLC activity of microsomes in anti-PLC-treated hearts. Furthermore, both the antiphospholipases attenuated the release of creatine kinase and lactate dehydrogenase into perfusate and increased contractility as well as coronary flow in the reperfused hearts. Results of this study suggest that both PLA2 and PLC are involved in the degradation of phospholipids and cellular injury that occur during reperfusion of ischemic myocardium.


2016 ◽  
Vol 62 (3-4) ◽  
pp. 171-177 ◽  
Author(s):  
Ling-Ying Shuai ◽  
Yan-Ling Song ◽  
Burt P. Kotler ◽  
Keren Embar ◽  
Zhi-Gao Zeng

We studied the foraging behaviour of two sympatric rodents (Meriones meridianus and Dipus sagitta) in the Gobi Desert, Northwestern China. The role of the foraging behaviour in promoting species coexistence was also examined. We used giving-up densities (GUDs) in artificial food patches to measure the patch use of rodents and video trapping to directly record the foraging behaviour, vigilance, and interspecific interactions. Three potential mechanisms of coexistence were evaluated (1) microhabitat partitioning; (2) spatial heterogeneity of resource abundance with a tradeoff in foraging efficiency vs. locomotion; and (3) temporal partitioning on a daily scale. Compared to M. meridianus, D. sagitta generally possessed lower GUDs, spent more time on patches, and conducted more visits per tray per capita, regardless of microhabitat. However, M. meridianus possessed advantages in average harvesting rates and direct interference against D. sagitta. Our results only partly support the third mechanism listed above. We propose another potential mechanism of coexistence: a tradeoff between interference competition and safety, with M. meridianus better at interference competition and D. sagitta better at avoiding predation risk. This mechanism is uncommon in previously studied desert rodent systems.


2014 ◽  
Author(s):  
James Trousdale ◽  
Samuel R. Carroll ◽  
Fabrizio Gabbiani ◽  
Krešimir Josić

Coupling between sensory neurons impacts their tuning properties and correlations in their responses. How such coupling affects sensory representations and ultimately behavior remains unclear. We investigated the role of neuronal coupling during visual processing using a realistic biophysical model of the vertical system (VS) cell network in the blow fly. These neurons are thought to encode the horizontal rotation axis during rapid free flight manoeuvres. Experimental findings suggest neurons of the vertical system are strongly electrically coupled, and that several downstream neurons driving motor responses to ego-rotation receive inputs primarily from a small subset of VS cells. These downstream neurons must decode information about the axis of rotation from a partial readout of the VS population response. To investigate the role of coupling, we simulated the VS response to a variety of rotating visual scenes and computed optimal Bayesian estimates from the relevant subset of VS cells. Our analysis shows that coupling leads to near-optimal estimates from a subpopulation readout. In contrast, coupling between VS cells has no impact on the quality of encoding in the response of the full population. We conclude that coupling at one level of the fly visual system allows for near-optimal decoding from partial information at the subsequent, pre-motor level. Thus, electrical coupling may provide a general mechanism to achieve near-optimal information transfer from neuronal subpopulations across organisms and modalities.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1424 ◽  
Author(s):  
Murray A. Rudd

Using an international dataset compiled from 121 sites in 87 marine protected areas (MPAs) globally (Edgar et al., 2014), I assessed how various configurations of design and management conditions affected MPA ecological performance, measured in terms of fish species richness and biomass. The set-theoretic approach used Boolean algebra to identify pathways that combined up to five ‘NEOLI’ (No-take,Enforced,Old,Large,Isolated) conditions and that were sufficient for achieving positive, and negative, ecological outcomes. Ecological isolation was overwhelming the most important condition affecting ecological outcomes butOldandLargewere also conditions important for achieving high levels of biomass among large fishes (jacks, groupers, sharks). Solution coverage was uniformly low (<0.35) for all models of positive ecological performance suggesting the presence of numerous other conditions and pathways to ecological success that did not involve the NEOLI conditions. Solution coverage was higher (>0.50) for negative results (i.e., the absence of high biomass) among the large commercially-exploited fishes, implying asymmetries in how MPAs may rebuild populations on the one hand and, on the other, protect against further decline. The results revealed complex interactions involving MPA design, implementation, and management conditions that affect MPA ecological performance. In general terms, the presence of no-take regulations and effective enforcement were insufficient to ensure MPA effectiveness on their own. Given the central role of ecological isolation in securing ecological benefits from MPAs, site selection in the design phase appears critical for success.


2019 ◽  
Vol 20 (1) ◽  
pp. 1-13
Author(s):  
Isabel Cardim De Resende ◽  
Patrícia Gonçalves Guedes ◽  
Shirley Seixas Pereira Da Silva ◽  
Alexandre Maurício Carneiro

Studies about bats biology encompassing diet, reproduction and parasitology are important to understand the role of these small animals in the ecosystem. However, few studies present such information. Therefore, the present paper was made to congregate information about biology of Phyllostomus hastatus, and compare the results between two urban parks at Rio de Janeiro City (Rio de Janeiro, Brazil): Parque Natural Municipal da Freguesia (PNMF) and Parque Estadual da Pedra Branca (PEPB), the latter being considerably larger than the other one. Long-term fieldworks were conducted in both areas and data on biometry, reproduction, parasites and diet were assembled. Animals were captured in mists nets and put in cotton sacs, from where fecal material was collected for further analysis. They were measured alive and inspected for reproductive stage; ectoparasites were collected and blood smears were made whenever possible. Bats were released at the end of the fieldwork. The feces and blood material were analyzed at the lab. Thus, 53 specimens of Phyllostomus were captured, 13 from PNMF and 40 from PEPB. We found individuals with smaller measurements at the most anthropized park – the Freguesia Park; reproduction occurred between September and December at both parks; diet included Curcubitaceae, Urticaceae, Bombacaceae, Lythraceae, Coleoptera, Lepidoptera, Hemiptera and Diptera. Concerning ectoparasites, Diptera and Acari were recorded; no haemoparasites were found in the blood smears. Although specimens from the smaller park seem to be most affected by anthropization, our results reinforce the idea that the creation of small parks is important for species maintenance, since it may serve as ecological corridor and as a food source for the animals.


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