Search results for "Fora"
showing 10 items of 1086 documents
Fosfātu noteikšana augsnē ar eksprestestu metodi
2021
Fosfātu noteikšana augsnē ar eksprestestu metodi. Medne L.T., zinātniskais vadītājs Jānis Ģībietis. Bakalaura darbs satur 77 lapaspuses, 26 attēlus, 20 tabulas, 39 informācijas avotus, 10 pielikumus. Latviešu valodā. Darbā apkopota informācija par dažādiem fosfātu eksprestestiem, fosfātu ekstrakcijas metodēm no augsnes, augsnes paraugu ņemšanas principiem un dažādām fosfātu noteikšanas metodēm. Eksperimentālajā daļā pārbaudīta fosfātu ūdens eksprestestu izmantošana dažādiem augsnes paraugu ekstraktiem, kas iegūti ar dažādiem ekstrahentiem. Pētīta rezultātu atšķirības fosfora pentoksīda daudzumam augsnes paraugos, kas iegūta no dažādiem ekstrahentiem, kā arī daļai ekstraktu eksprestestu rezu…
Benthic foraminiferal assemblage turnover during intensification of the Northern Hemisphere glaciation in the Piacenzian Punta Piccola section (South…
2012
Abstract We present the results of a high-resolution analysis of the benthic foraminiferal assemblages at the Punta Piccola section (Stratotype for the Piacenzian Stage), which spans the gradual climate transition of the intensification of the Northern Hemisphere glaciation (3.6–2.6 Ma). This study highlighted a major benthic foraminiferal fauna turnover, which started at about 3.05 Ma with LO of Cibicidoides italicus , registered the gradual decline of Stilostomella spp. and culminated at about 2.7–2.75 Ma, when the dominant Siphonina reticulata was replaced by Cibicidoides pachyderma , costate Bulimine, spinose Bulimine, spinose Uvigerine and the Bolivina dilatata group. Four compositiona…
Influence of fish aggregating devices (FADs) on anti-predator behaviour within experimental mesocosms
2015
Commercial fishers have used fish aggregating devices throughout the Mediterranean Sea for over 40 years. These devices attract numerous predatory and forage species in both coastal and offshore environments. This study examined the influence of fish aggregating devices on schooling and aggregating behaviour by small forage fish in quasi-natural mesocosms. Anti-predator behaviour was evaluated for juvenile Caranx crysos under a variety of treatment conditions. Results suggest that, in the absence of physical structure, C. crysos first respond to a predatory threat by forming a school. When a physical structure is present, however, C. crysos show an occasional tendency to aggregate near the …
Contrasting structural complexity differentiate hunting strategy in an ambush apex predator.
2021
AbstractStructural complexity is known to influence prey behaviour, mortality and population structure, but the effects on predators have received less attention. We tested whether contrasting structural complexity in two newly colonised lakes (low structural complexity lake—LSC; high structural complexity—HSC) was associated with contrasting behaviour in an aquatic apex predator, Northern pike (Esox lucius; hereafter pike) present in the lakes. Behaviour of pike was studied with whole-lake acoustic telemetry tracking, supplemented by stable isotope analysis of pike prey utilization and survey fishing data on the prey fish community. Pike displayed increased activity, space use, individual …
Scavenging in the realm of senses: smell and vision drive recruitment at carcasses in Neotropical ecosystems
2022
Social information, acquired through the observation of other individuals, is especially relevant among species belonging to the same guild. The unpredictable and ephemeral nature of carrion implies that social mechanisms may be selected among scavenger species to facilitate carcass location and consumption. Here, we apply a survival-modelling strategy to data obtained through the placement and monitoring of carcasses in the field to analyse possible information transmission cascades within a Neotropical scavenger community. Our study highlights how the use of different senses (smell and sight) within this guild facilitates carcass location through the transmission of social information bet…
The forager's dilemma: food sharing and food defense as risk-sensitive foraging options.
2003
Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently la…
A Linguistic Analysis of the Online Debate on Vaccines and Use of Fora as Information Stations and Confirmation Niche
2017
This study looks at the communication between users concerning health risks, with the aim of exploring their use of fora and assessing whether participants establish a niche with like-minded users during these exchanges. By integrating a corpus linguistic approach with content analysis and multiple studies on computer mediated health discourse, this study analyses the intense attention paid to the correlation between the Measles Mumps Rubella (MMR) vaccine and autism, as an example of elaboration of the message and risk of emotive amplification, with fora working as echo chambers. Results include: a) a qualitative analysis of the content of posts and their qualification, b) a focus on the t…
The proanthocyanidin content as a tool to differentiate between Lotus tenuis and L. corniculatus individuals
2012
Abstract Lotus tenuis Wald et Kit and Lotus corniculatus L. are conspicuous elements of the agricultural landscape for cattle production. In South America, commercial L. tenuis stocks usually present contaminations with L. corniculatus, what brings about an important economical injure to the forage producers. A way to reduce or avoid loses is to assess the purity degree of L. tenuis seed lots before seeding. Methods so far described for the diagnosis of Lotus species when flowers are not available are lengthy, time consuming, need the implementation of sophisticated laboratories and are relatively expensive. It has been shown that Lotus species accumulate variable proanthocyanidins amounts,…
Effects of male removal on female foraging behavior in the Eurasian treecreeper
1997
In old, spruce-dominated forests of central Finland, Eurasian treecreepers Certhia familiaris divide their territories spatially during the breeding season. Females forage primarily on the upper parts of the tree trunks, while males use the lower parts of the tree trunks. In this study we removed males from eight territories in the early nestling period to see if the mate's absence would change the foraging patterns of the resident female. Widowed females foraged at lower heights, thus behaving more like paired males. These females also spent less time on each tree and on each foraging bout than did paired females. We conclude that male removal facilitated the change in a female's foraging …