Search results for "COMPETITION"

Competition for nest-boxes among four vertebrate species: an experimental study in orange groves

1990

The experiment was carried out in eastern Spain from 1986 to 1988. The nest-boxes were placed at the height where natural holes occur, visited twice a week, and cleaned after every breeding season. Four vertebrate species used the nest-boxes: great tit Parus major, house sparrow Passer domesticus, tree sparrow Passer montanus, and black rat Rattus rattus. The first species to occupy the nest-boxes, the great tit, was the least able to defend them. During the third year breeding by the great tit in the nest-boxes decreased markedly, probably due to the increase of house sparrow and black rat occupation. We suggest that differences among species in their ability to discover and use new holes …

Environmental DNA analysis indicates that migration barriers are decreasing the occurrence of European eel (Anguilla anguilla) in distance from the s…

2020

Abstract The European eel (Anguilla L.) is considered critically endangered by the IUCN Red List, and recruitment remains low. One of the challenges for the species today is migration barriers that limit their habitat. Along the Norwegian coast, like in other countries, the abundance of eels appears to decrease with distance from the sea. This pattern may be a result of factors like water temperature, water quality, competition, and habitat suitability and availability. This study aims to use environmental DNA (eDNA) analysis to investigate the potential relationship between migration barriers and the decreasing occurrence of eels in distance from the sea by the coast of southern Norway. Si…

The Requirement of Space and Equipment in the Ambulance

1968

The death penalty in Valencia (1450-1500), numbers, urban spaces and funeral ritualities from the Brotherhood of Innocents and Helpless

2021

Mediante una combinación de fuentes documentales de origen y procedencia diversa, se han computado fehacientemente 737 ejecuciones en Valencia entre los años 1450 y 1500. El artículo analiza este aspecto de la realidad social, judicial y política de la Valencia del Renacimiento a la luz de los recientes planteamientos historiográficos sobre la materia. Se destaca el impacto del Santo Oficio (a partir de 1482) dentro del contexto penal de la ciudad, se analiza el papel restaurador y reconciliador de la Cofradía de Inocentes y Desamparados, y se aborda la contribución de esta singular hermandad a la re-significación de los espacios urbanos y periurbanos. Through a combination of documentary s…

Single Peptide Backbone Surrogate Mutations to Regulate Angiotensin GPCR Subtype Selectivity

2020

Mutating the side-chains of amino acids in a peptide ligand, with unnatural amino acids, aiming to mitigate its short half-life is an established approach. However, it is hypothesized that mutating specific backbone peptide bonds with bioisosters can be exploited not only to enhance the proteolytic stability of parent peptides, but also to tune its receptor subtype selectivity. Towards this end, four [Y]6-Angiotensin II analogues are synthesized where amide bonds have been replaced by 1,4-disubstituted 1,2,3-triazole isosteres in four different backbone locations. All the analogues possessed enhanced stability in human plasma in comparison with the parent peptide, whereas only two of them a…

Community and space in Italian sociolinguistics. The experience of the <i>Linguistic Atlas of Sicily</i> (<i>Atlante Linguistico de…

2018

Our paper focuses on the notions of ‘space’ and ‘community’ within the most recent developments of Italian sociolinguistics. This research area has roots in the tradition of Italian geolinguistic studies and has been enhanced by other research traditions. In fact, Italian sociolinguistics has reused the relationship between ‘community’ and ‘space’ investigated in the early twentieth century by Benvenuto Terracini’s (1886–1968) seminal studies on ‘minimal linguistic point’ (‘punto linguistico minimo’) and on ‘community of speakers’. Since the 1970s and, with more weight, in the last decades, some important contributions coming from scholars such as Alberto Sobrero, Tullio Telmon and Giovanni…

Indirect effects of invasive crayfish on native fish parasites

2013

Interactions between invasive and native species are often modified by parasites. One little-studied scenario is that invasive species affect parasite transmission to native hosts by altering the relative abundance of hosts needed in parasite life cycles, for example by predation on these hosts. Here we show that presence of an invasive crayfish species, Pacifastacus leniusculus, decreases the mean abundance of native parasites transmitted from snails and aquatic isopods to perch, Perca fluviatilis, in two large boreal lakes in Finland. In contrast, parasites transmitted to the fish from planktonic copepods or mussels, hosts not readily preyed on by crayfish, were not affected by crayfish p…

Host immunization shapes interspecific associations in trematode parasites

2009

1. Individuals of free-living organisms are commonly infected by multiple parasite species. Under such circumstances, positive or negative associations between the species are possible because of direct or indirect interactions, details in parasite transmission ecology and host-mediated factors. One possible mechanism underlying these processes is host immunity, but its role in shaping these associations has rarely been tackled experimentally. 2. In this study, we tested the effect of host immunization on associations between trematode parasites infecting eyes of fish. We first analysed the associations between three species (Diplostomum spathaceum, Diplostomum gasterostei and Tylodelphys c…

Morphological variation of perchPerca fluviatilisin humic lakes: the effect of predator density, competition and prey abundance

2010

Between and within-lake variations in morphology of perch Perca fluviatilis were studied in four humic lakes in eastern Finland. Perca fluviatilis were more streamlined and smaller headed in a lake with the highest abundance of cyprinids, but lowest abundance of predators (Lake Tuopanjarvi), indicating adaptation to planktivorous feeding and low predator density. Highest bodied fish were found from a lake with the lowest cyprinid but highest predator abundance (Lake Koppelojarvi), which conversely indicates adaptation to more effective predator avoidance. Furthermore, the length of the paired fins was longest in Lake Kinnasjarvi and Lake Tuopanjarvi, where the abundance of benthic macroinve…

NUTRITIONAL AND HORMONAL FACTORS AFFECTING FRUIT SET IN AVOCADO (Persea americana Mill.)

2017

Under favourable conditions, the avocado sets more fruits than the tree is able to bring to maturity, so that the plant adjusts, during the early stages of development, its ability to nourish them by modifying their number, that is, causing the fruit drop of those who can not maintain their growth rate. Accordingly, carbohydrate availability could be a key factor in the physiological abscission of these fruits. Since this species presents dichogamy, the abscission of fruits has also been attributed to the absence of pollination, but at the same time it has been related to failures in seed development, embryo abortion, seed coat collapse, and with the effect of an environmental stress, espec…