87 research outputs found
Breeding behaviour of a tropical bird: a study of the blue-throated Bee-eater (Merops viridis) using relational database and DNA fingerprinting.
The breeding behaviour of the Blue-throated Bee-eater was studied at two colonies in Peninsula
Malaysia during 3 breeding seasons, with particular emphasis on pair behaviour, mixed reproductive
strategies and nestling competition. This is the first study of vertebrate social behaviour and ecology
to contain the documentation of a relational database. This was designed to store and manipulate all
data obtained from regular captures and biometric measurements of adults and nestlings and from
observations of adults. DNA fingerprinting was used to establish the true genetic relationships between
nestlings and their social parents: most nestlings were genetic offspring (72%). Nestlings were
classified as illegitimate offspring using 95% confidence intervals of the band sharing coefficient and
number of unexplained nestling bands as criteria. Very few if any nestlings were sired by an extra-pair
male (fewer than 5%). Behavioural evidence of strong cooperation between pair members throughout
the breeding season supports the DNA fingerprinting results of no confirmed case of offspring fathered
by extra-pair males (extra-pair offspring; EPO). The Blue-throated Bee-eater probably has a near
monogamous mating system. Most illegitimate nestlings had been 'dumped'. They were either the
result of intra-specific nest parasitism (INP; 7%) or of 'quasi' parasitism (the offspring of the pair-male
and an extra-pair female; 7-12%). INP by relatives of the hosts could have explained some
intermediate band sharing coefficients. Anti-INP behaviour was demonstrated when experimentally
'dumped' eggs were almost always expelled before the onset of laying, but never afterwards. DNA
fingerprinting showed that relatives may roost together and that related males may nest close together.
Compared with other colonial Bee-eaters, M. viridis had low levels of helping-at-the-nest and EPO,
but similar or higher levels of INP.
The high nestling mortality in Blue-throated Bee-eaters was explained by a combination of three
hypotheses, some of which were tested by experiment. (1) Insurance: extra-eggs are needed to counter
hatch failure. (2) Brood reduction (including resource tracking): in times of food constraint, the laterhatched
nestlings in asynchrously hatched broods starve. (3) Anti-INP hypothesis: these later-hatched
nestlings are eliminated because they are likely to be illegitimate. Hatching failure was about 1 in 3
eggs overall. Help from the male allows an early onset of incubation which results in asynchronous
hatching. Nestling hunger was shown to be a proximate factor affecting runt mortality both directly
through competition and indirectly through nestling aggression. The demise of runts was delayed when
conditions improved. Blue-throated Bee-eater broods are severely limited by food. Under this severe
brood size constraint, breeding females may increase reproductive output by 'dumping' their last egg.
This leads to the high frequency of INP observed in Blue-throated Bee-eaters. An early onset of
incubation also gives the first-laid egg(s) a temporal developmental advantage over subsequently
'dumped' parasitic eggs. The 'dumped' nestlings are eliminated by starvation and siblicide, which may
itself be an adaptation to INP to eliminate of unrelated nestlings
Consensus recommendations on the treatment of opioid use disorder in the emergency department
The treatment of opioid use disorder with buprenorphine and methadone reduces morbidity and mortality in patients with opioid use disorder. The initiation of buprenorphine in the emergency department (ED) has been associated with increased rates of outpatient treatment linkage and decreased drug use when compared to patients randomized to receive standard ED referral. As such, the ED has been increasingly recognized as a venue for the identification and initiation of treatment for opioid use disorder, but no formal American College of Emergency Physicians (ACEP) recommendations on the topic have previously been published. The ACEP convened a group of emergency physicians with expertise in clinical research, addiction, toxicology, and administration to review literature and develop consensus recommendations on the treatment of opioid use disorder in the ED. Based on literature review, clinical experience, and expert consensus, the group recommends that emergency physicians offer to initiate opioid use disorder treatment with buprenorphine in appropriate patients and provide direct linkage to ongoing treatment for patients with untreated opioid use disorder. These consensus recommendations include strategies for opioid use disorder treatment initiation and ED program implementation. They were approved by the ACEP board of directors in January 2021
Queer Youth and the Culture Wars: From Classroom to Courtroom in Australia, Canada and the United States
This article builds on Lugg\u27s (2006) discussion of surveillance in public schools and how queer youth are resisting schools\u27 current efforts to regulate sexual orientation and gender expression in the U.S. and internationally. Legal complaints initiated by queer youth against their schools for harassment and access to extra-curricular activities are discussed. The number of cases in the past five years has increased significantly and the courts are siding with the youth and their allies, demonstrating that queer youth are significantly impacting the dismantling of heteronormative regulatory regimes and improving the school experiences for themselves and queer adults
Langfristprognose des Luftverkehrs Deutschlands. Ergebnisse des engpaßfreien Referenz-Szenarios 2010
- …