scholarly journals Host density predicts the probability of parasitism by avian brood parasites

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180204 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Spatial Distribution ◽  
Reproductive Success ◽  
Host Species ◽  
Field Data ◽  
Host Density ◽  
Brood Parasites ◽  
Parasitism Rates ◽  
Analyse Data ◽  
First Time ◽  
Determining Factor

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals The costs of avian brood parasitism explain variation in egg rejection behaviour in hosts

2015 ◽  
Vol 11 (7) ◽  
pp. 20150296 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Comparative Analysis ◽  
Host Species ◽  
Brood Parasitism ◽  
Large Scale ◽  
Bird Species ◽  
Egg Rejection ◽  
Brood Parasites ◽  
Avian Brood Parasitism ◽  
First Time ◽  
Rejection Rates

Many bird species can reject foreign eggs from their nests. This behaviour is thought to have evolved in response to brood parasites, birds that lay their eggs in the nest of other species. However, not all hosts of brood parasites evict parasitic eggs. In this study, we collate data from egg rejection experiments on 198 species, and perform comparative analyses to understand the conditions under which egg rejection evolves. We found evidence, we believe for the first time in a large-scale comparative analysis, that (i) non-current host species have rejection rates as high as current hosts, (ii) egg rejection is more likely to evolve when the parasite is relatively large compared with its host and (iii) egg rejection is more likely to evolve when the parasite chick evicts all the host eggs from the nest, such as in cuckoos. Our results suggest that the interactions between brood parasites and their hosts have driven the evolution of egg rejection and that variation in the costs inflicted by parasites is fundamental to explaining why only some host species evolve egg rejection.

Conference report: innovation, interaction … and a lot of data: first time reflections on Internet Librarian International, UK 2018

2019 ◽  
Vol 36 (2) ◽  
pp. 21-22
Author(s):  
Ray Harper
Keyword(s):  
Best Practice ◽  
New Technologies ◽  
Conference Report ◽  
Library Services ◽  
New Techniques ◽  
Content Type ◽  
Making A Difference ◽  
Analyse Data ◽  
Physical Spaces ◽  
First Time

Purpose The purpose of this paper is to summarise a number of presentations at Day 1 of the Internet Librarian International conference, London, UK (16 October 2018). This was the 20th conference in the series, and the three key themes included were the next-gen library and librarian; understanding users, usage and user experience; and inclusion and inspiration: libraries making a difference. Design/methodology/approach This paper reports from the viewpoint of a first-time attendee of the conference. This summarises the main issues raised by each presentation and draws out the key learning points for practical situations. Findings The conference covered a variety of practical ways in which libraries can use technology to support users and make decisions about services. These include developing interactive physical spaces which include augmented reality; introducing “chat-bots” to support users; using new techniques to analyse data; and piloting new ways to engage users (such as coding clubs). A key theme was how we use and harness data in a way that is ethical, effective and relevant to library services. Originality/value This conference focussed on practical examples of how library and information services across sectors and countries are innovating in a period of huge change. The conference gave delegates numerous useful ideas and examples of best practice and demonstrated the strength of the profession in adapting to new technologies and developments.

scholarly journals Exchange Speed of Four-Component Nanorotors Correlates with Hammett Substituent Constants

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 116-125
Author(s):  
Yi-Fan Li ◽  
Amit Ghosh ◽  
Pronay Kumar Biswas ◽  
Suchismita Saha ◽  
Michael Schmittel
Keyword(s):  
Linear Correlation ◽  
Bond Cleavage ◽  
Head Group ◽  
Ligand Interaction ◽  
Exchange Frequency ◽  
Rate Determining Step ◽  
Head Groups ◽  
Substituent Constants ◽  
First Time ◽  
Determining Factor

Three distinct four-component supramolecular nanorotors were prepared, using, for the first time, bipyridine instead of phenanthroline stations in the stator. Following our established self-sorting protocol to multicomponent nanodevices, the nanorotors were self-assembled by mixing the stator, rotators with various pyridine head groups, copper(I) ions and 1,4-diazabicyclo[2.2.2]octane (DABCO). Whereas the exchange of a phenanthroline vs. a bipyridine station did not entail significant changes in the rotational exchange frequency, the para-substituents at the pyridine head group of the rotator had drastic consequences on the speed: 4-OMe (k298 = 35 kHz), 4-H (k298 = 77 kHz) and 4-NO2 (k298 = 843 kHz). The exchange frequency (log k) showed an excellent linear correlation with both the Hammett substituent constants and log K of the copper(I)–ligand interaction, proving that rotator–copper(I) bond cleavage is the key determining factor in the rate-determining step.

First-time mothers' experiences of the first stage of labour in hospitals in the HhoHho region, Eswatini

2021 ◽  
Vol 15 (1) ◽  
pp. 1-8
Author(s):  
Nonhlahla Mamba ◽  
Oslinah B Tagutanazvo
Keyword(s):  
Normal Vaginal Delivery ◽  
Hospital Data ◽  
Face To Face ◽  
First Time Mothers ◽  
Open Coding ◽  
Analyse Data ◽  
Labour Pains ◽  
Postpartum Mothers ◽  
First Time ◽  
Purposive Sample

Background/Aims Women have different and varying experiences of labour and their coping strategies vary as well. Having support during labour may help women feel in control of their labour. This study aimed to explore and describe the experiences of first-time mothers during the first stage of labour. Methods The study used a qualitative, exploratory, descriptive design. A purposive sample of nine first-time postpartum mothers were selected to participate following normal vaginal delivery at Mbabane Government Hospital. Data were collected through face-to-face interviews and analysed thematically. Open coding was used to analyse data. Results Four themes emerged: 1. Ignorance of the signs of labour 2. Anxiety related to fear 3. Maintaining adequate nutrition 4. Coping with labour pains. Each theme had several subcategories. Most participants were ignorant of the signs of labour and reported anxiety related to fear of the unknown and practiced different ways of coping with labour pains. Conclusions First-time mothers require adequate preparation for labour, as many women in this study were ignorant of the signs of labour and reported anxiety related to fear of the unknown. Pregnant women should be educated about the physiological aspects of the first stage of labour and oriented in the labour ward during the prenatal period.

scholarly journals Hydrochemical Characteristics of the Surgut Reservoir Water Area Littoral Sections

2018 ◽  
Author(s):  
Keyword(s):  
Spatial Distribution ◽  
Power Plants ◽  
Thermal Power ◽  
Water Area ◽  
The Other ◽  
Anthropogenic Pressure ◽  
Taiga Zone ◽  
Thermal Power Plants ◽  
Reservoir Water ◽  
First Time

Cooling reservoirs of thermal power plants represent the special class of natural/ engineering systems with, on the one hand, natural geo/systems as one subsystem and, on the other hand, production/technological units as the other subsystem. Studying of these ecosystems’ functioning regularities seems to be helpful for water quality management and rational organization of water use. Besides, it is topical due to the low level of the relevant knowledge in the North of the Western Siberia. The authors for the first time in the Middle Ob Region have carried out a two-year session of monitoring of hydro/chemical indicators and temperature regime of the thermal power plants cooling reservoirs in the riparian stripe of water area. All previous investigations were done only by industrial water users within the frameworks of production monitoring in terms of three indicators in three points of the cooling reservoir water area downstream the power plant dam. Spatial distribution of concentrations of biogenic ions, salt composition, pH, organic matter, and metals in specific natural/technological system of the Surgut hthermal power plants’ reservoirs has been analyzed for the first time for the conditions of the Western Siberian taiga zone. Sources of anthropogenic pressure upon a water body have been identified. According the results of the indicators’ spatial distribution analysis three sections of the Surgut reservoir water area have been separated: a background section of the Chernaya River; a section upstream the dam with predominantly recreational character of the anthropogenic pressure; and a sectio0n downstream the dam with anthropogenic pressure of technological origin. According the outcomes of the correlation analysis indicators of the anthropogenic pressure character have been reveald.

scholarly journals Effect of Droplet Size and Counterions on the Spatial Distribution of Ions

2019 ◽  
Author(s):  
Victor Kwan ◽  
Styliani Consta
Keyword(s):  
Spatial Distribution ◽  
Reaction Mechanisms ◽  
Charge Carriers ◽  
Transfer Reactions ◽  
Spatial Distributions ◽  
Hydronium Ions ◽  
Ionic Atmosphere ◽  
Droplet Sizes ◽  
Charge Transfer Reactions ◽  
First Time

Electrosprayed droplets have emerged as a new environment for accelerating chemical reactions by orders of magnitude relative to their bulk analogues. Nevertheless the reaction mechanisms are still unknown. Unraveling the ion spatial distribution is critical as to where charge transfer reactions are likely to take place and as to their effect on the ionic atmosphere of macroions. Here we investigate the ion spatial distributions in aqueous droplets with diameters in the range of 5 nm to 16 nm with and without counterions using molecular dynamics. The charge carriers are Na, Cl ions and model hydronium ions. For the first time droplet sizes that are accessible to experimental scrutiny are modeled atomistically. <br>

scholarly journals Nematofauna of bank vole: Clethrionomys glareolus (Schreber, 1780) from Mt. Fruska gora (Serbia)

2009 ◽  
Vol 61 (3) ◽  
pp. 555-561 ◽  
Author(s):  
Olivera Bjelic-Cabrilo ◽  
Ester Popovic ◽  
Smiljka Simic ◽  
Desanka Kostic
Keyword(s):  
Bank Vole ◽  
Host Species ◽  
National Park ◽  
Nematode Species ◽  
Clethrionomys Glareolus ◽  
Parasite Invasion ◽  
Mean Intensity ◽  
Aspiculuris Tetraptera ◽  
First Time

The nematofauna of bank vole (Clethrionomys glareolus) was analyzed for the first time from samples collected in our country. The specimens were collected in Fruska Gora National Park (locality of Brankovac). The number of collected specimens was 138, and infestation with seven nematode species was determined: Heligmosomum mixtum (Schulz, 1954), Heligmosomoides glareoli (Baylis, 1928), Syphacia petrusewiczi (Bernard, 1966), S. stroma (Linstow, 1884), Capillaria murissylvatici (Dieseng, 1851), Trichocephalus muris Schrank, 1788, and Aspiculuris tetraptera (Nitzsch, 1821). The species Heligmosomum mixtum, Heligmosomoides glareoli, and Syphacia petrusewiczi represent the first records for the territory of our country. The species best represented in the sample were H. glareoli and S. petrusewiczi. There were no statistically significant differences between the sexes of host species regarding the prevalence, mean intensity, or mean abundance of parasite invasion.

scholarly journals Naturalized Dolichogenidea gelechiidivoris Marsh (Hymenoptera: Braconidae) complement the resident parasitoid complex of Tuta absoluta (Meyrick) (Lepidopera:Gelechiidae) in Spain

2021 ◽  
Author(s):  
Carmen Denis ◽  
JORDI RIUDAVETS ◽  
OSCAR ALOMAR ◽  
NURIA AGUSTI ◽  
HELENA GONZALEZ-VALERO ◽  
...  
Keyword(s):  
Biological Control ◽  
Biocontrol Agent ◽  
Natural Populations ◽  
Tuta Absoluta ◽  
Parasitoid Complex ◽  
Parasitism Rates ◽  
Production Area ◽  
Side Walls ◽  
Predatory Mirid ◽  
First Time

Our study aimed to assess the contribution of natural parasitism due to Necremnus tutae Ribes & Bernardo (Hymenoptera: Eulophidae) to the biological control of Tuta absoluta (Meyrick) (Lepidopera:Gelechiidae) in commercial plots where an IPM program based on the use of predatory mirid bugs was implemented. During the samplings, the presence of another parasitoid was detected and, therefore, a second part of our study intended to identify this species and to evaluate the importance of its natural populations in the biological control of the pest. Leaflets with T. absoluta galleries were collected during 2017-2020 from commercial tomato plots in the horticultural production area of Catalonia (Northeast Spain), including greenhouses, open fields, and roof covered tunnels that lack side walls. In the laboratory, T. absoluta larvae were classified as ectoparasitized, alive, or dead. Reared parasitoids from ectoparasitized larvae were mostly morphologically identified as Necremnus sp. with parasitism rates that peaked in summer months with values between 9 and 15%. Some of these ectoparasitized larvae also yielded another parasitoid identified as Dolichogenidea gelechiidivoris Marsh (Hymenoptera: Braconidae) by both morphological and molecular-DNA barcoding methods. In 2020, parasitism rates due to D. gelechiidivoris that increased with season up to 22%. Our work reports for the first time in Europe the presence of the neotropical species D. gelechiidivoris adding this biocontrol agent to the resident parasitoid complex of T. absoluta in Spain.

scholarly journals Occurrence of Amblyomma rotundatum Koch, 1844 on Epicrates assisi Machado, 1945 in João Pessoa, Paraíba, Brazil

2021 ◽  
Vol 15 (4) ◽  
pp. 335-338
Author(s):  
Aksa Ingrid Vieira Batista ◽  
Gabriel Vinicius Carvalho de Lucena ◽  
Kleber Silva de Oliveira Filho ◽  
Thiago Ferreira Lopes Nery ◽  
Thiago Fernandes Martins ◽  
...  
Keyword(s):  
Host Species ◽  
Tick Species ◽  
Wide Distribution ◽  
Dorsal Region ◽  
Taxonomic Key ◽  
Caatinga Biome ◽  
First Occurrence ◽  
First Time ◽  
Semi Arid

The Caatinga rainbow boa (Epicrates assisi Machado, 1945) is a snake belonging to the order Squamata, family Boidae, and subfamily Boinae. It has a wide distribution in Brazil and can be found in the Caatinga biome. The present study aims to report the first occurrence of Amblyomma rotundatum on E. assisi in the municipality of João Pessoa, Paraíba State (PB). On March 3, 2020, a tick collection was performed on the dorsal region of the head of an E. assisi, which was captive at the Arruda Câmara Zoobotanical Park, João Pessoa-PB. After collecting the tick, it was transferred to a flask containing 70º alcohol and sent to the Laboratory of Animal Parasitology of the Federal Rural University of the Semi-Arid (UFERSA) for analysis. Identification was done with the aid of a stereomicroscope using a taxonomic key. The result identified this specimen as a nymph of A. rotundatum. The occurrence of this tick species on E. assisi is reported for the first time and constitutes new data applicable to the ectoparasites that occur in this host species in Brazil.

Diversity, distribution and parasitism rates of fleas (Insecta: Siphonaptera) on sigmodontine rodents (Cricetidae) from Argentinian Patagonia

2018 ◽  
Vol 109 (1) ◽  
pp. 72-83 ◽  
Author(s):  
J. Sanchez ◽  
M. Lareschi
Keyword(s):  
Host Species ◽  
Arid Regions ◽  
Epidemiological Studies ◽  
Surveillance Systems ◽  
Parasitism Rate ◽  
Host Environment ◽  
Ecological Aspects ◽  
Parasitism Rates ◽  
Survival And Development ◽  
Causative Agents

AbstractFleas have great medical relevance as vectors of the causative agents of several diseases in animals and humans and rodents are the principal reservoirs for these pathogens. Argentinian Patagonia has the highest diversity of rodent fleas in South America. However, parasitism rates of rodents by fleas, the factors that influence them and the ecological aspects that modulate geographical distributions of flea–host association remain unknown for this region. This is the first study to record the diversity, prevalence, abundance, geographical distributions and host ranges of fleas in Argentinian Patagonia. It also compares parasitism rates among Patagonian ecoregions and host species. We captured 438 rodents belonging to 13 species, which harboured 624 fleas from 11 species and subspecies (P = 46%; mean abundance = 1.44). The high parasitism rates obtained were consistent with previous records for other arid regions, suggesting that Patagonia favours the survival and development of Siphonaptera. Host geographic range and abundance were related to the parasitological indexes: host species with high-density populations had the highest mean flea abundance and prevalence, whereas widely distributed hosts had the highest richness and diversity of flea species. Our results contribute to the knowledge of the flea–host–environment complex. Our analysis of flea distributions and parasitism rate in Central Patagonia may be useful in epidemiological studies of flea-borne diseases and provide a basis for implementing surveillance systems for better risk assessment of emerging zoonoses in the region.

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