18 research outputs found
Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?
Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load.
Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests.
Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates
University student engagement inventory (USEI): psychometric properties
Academic engagement describes students’ investment in academic learning and achievement and is an important indicator of
students’ adjustment to university life, particularly in the first year. A tridimensional conceptualization of academic engagement
has been accepted (behavioral, emotional and cognitive dimensions). This paper tests the dimensionality, internal consistency
reliability and invariance of the University Student Engagement Inventory (USEI) taking into consideration both gender and the
scientific area of graduation. A sample of 908 Portuguese first-year university students was considered. Good evidence of
reliability has been obtained with ordinal alpha and omega values. Confirmatory factor analysis substantiates the theoretical
dimensionality proposed (second-order latent factor), internal consistency reliability evidence indicates good values and the results
suggest measurement invariance across gender and the area of graduation. The present study enhances the role of the USEI
regarding the lack of consensus on the dimensionality and constructs delimitation of academic engagement.Jorge Sinval received funding from the William James Center for Research, Portuguese Science Foundation (FCT UID/PSI/04810/2013). Leandro S. Almeida and Joana R. Casanova received funding from CIEd – Research Centre on Education, projects UID/CED/1661/2013 and UID/CED/1661/2016, Institute of Education, University of Minho, through national funds of FCT/MCTES-PT. Joana R. Casanova received funding from the Portuguese Science Foundation (FCT) as a Doctoral Grant, under grant agreement number SFRH/BD/117902/2016.info:eu-repo/semantics/publishedVersio
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Implementing a Restoration Program for the Endangered White Abalone (Haliotis sorenseni) in California
A restoration program including wild population surveys, captive breeding, health monitoring, recovery site preparation, and recovery modeling has been implemented to restore white abalone (Haliotis sorenseni) populations in California. White abalone once supported a lucrative fishery and are now endangered, nearing extinction at less than 1% of baseline abundances. Recent deep water surveys indicate that populations continue to decline with no signs of recruitment, despite the closure of the fishery in 1996. Four sites with artificial reefs (n=12/site) in optimal white abalone habitat were established. No wild white abalone have been found at these sites. Captive abalone were spawned in the spring of each year from 2012 to 2015. Each year, the production of 1-y-old abalone has increased in the captive breeding program from approximately 20 in 2012, to 150 in 2013 and an estimated 2,000 in 2014. In 2015, the breeding program reached two milestones: (1) most successful spawning season to date and (2) the hatchery distributed 200 captive-reared abalone to 4 partner institutions within the White Abalone Recovery Consortium (WARC). The WARC is made up of federal and state agencies, universities, public aquaria, and aquaculture organizations, all committed to white abalone restoration. The next steps for the program include expanding the captive breeding program to increase production, monitoring abalone health and genetic diversity, and conducting stocking studies to enhance growth and survival in the ocean. The goal of the stocking program is to create a reproductive population in the wild to bring white abalone back from the brink of extinction
Mountain gorilla lymphocryptovirus has Epstein-Barr virus-like epidemiology and pathology in infants
Epstein-Barr virus (EBV) infects greater than 90% of humans, is recognized as a significant comorbidity with HIV/AIDS, and is an etiologic agent for some human cancers. The critically endangered mountain gorilla population was suspected of infection with an EBV-like virus based on serology and infant histopathology similar to pulmonary reactive lymphoid hyperplasia (PRLH), a condition associated with EBV in HIV-infected children. To further examine the presence of EBV or an EBV-like virus in mountain gorillas, we conducted the first population-wide survey of oral samples for an EBV-like virus in a nonhuman great ape. We discovered that mountain gorillas are widely infected (n = 143/332) with a specific strain of lymphocryptovirus 1 (GbbLCV-1). Fifty-two percent of infant mountain gorillas were orally shedding GbbLCV-1, suggesting primary infection during this stage of life, similar to what is seen in humans in less developed countries. We then identified GbbLCV-1 in post-mortem infant lung tissues demonstrating histopathological lesions consistent with PRLH, suggesting primary infection with GbbLCV-1 is associated with PRLH in infants. Together, our findings demonstrate that mountain gorilla's infection with GbbLCV-1 could provide valuable information for human disease in a natural great ape setting and have potential conservation implications in this critically endangered species
Female reproductive activity and its endocrine correlates in the African lesser bushbaby, Galago moholi
Steroid hormones play an important role in
female reproductive physiology and behaviour and are
often used to monitor important female reproductive events.
However, such studies are often attempted on captive populations
alone, delivering limited data. One such example
is the African lesser bushbaby, Galago moholi, for which
contradicting observational data exist between captive and
free-ranging populations, while hormonal analyses have
only been obtained from a single captive population. To
extend and rectify the limited information, we monitored
faecal progestagen and oestrogen metabolite levels across
various important life history stages of both captive and
free-ranging G. moholi. We additionally recorded changes
in vaginal state as well as the occurrence of reproductive
and aggressive behaviour throughout the study. Data from
our captive population revealed an ovarian cycle length of
33.44 ± 0.59 days (mean ± SD), with follicular and luteal
phases of 14.2 ± 1.0 and 19.1 ± 1.5 days, respectively,
and an average pregnancy length of 128 ± 3.3 days. The initiation of female reproductive activity was closely linked
to an oestrus-related increase in faecal oestrogen metabolite
levels. Four of the seven captive females monitored in
our study conceived during the May mating period, with
one additional female fertilised in September, supporting
the idea that the September mating period functions as a
back-up for female G. moholi. Identified benchmark faecal
progestagen metabolite levels (non-pregnant: >1 μg/g dry
weight (DW), pregnant: >9 μg/g DW) should help researchers
to determine pregnancy status of randomly wild-caught
females in even a cross-sectional study setup.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1/2) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/3602017-02-28hb201