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1.
Biol Lett ; 13(4)2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28404820

RESUMO

In group-living mammals, the eviction of subordinate females from breeding groups by dominants may serve to reduce feeding competition or to reduce breeding competition. Here, we combined both correlational and experimental approaches to investigate whether increases in food intake by dominant females reduces their tendency to evict subordinate females in wild meerkats (Suricata suricatta). We used 20 years of long-term data to examine the association between foraging success and eviction rate, and provisioned dominant females during the second half of their pregnancy, when they most commonly evict subordinates. We show that rather than reducing the tendency for dominants to evict subordinates, foraging success of dominant females is positively associated with the probability that pregnant dominant females will evict subordinate females and that experimental feeding increased their rates of eviction. Our results suggest that it is unlikely that the eviction of subordinate females serves to reduce feeding competition and that its principal function may be to reduce reproductive competition. The increase in eviction rates following experimental feeding also suggests that rather than feeding competition, energetic constraints may normally constrain eviction rates.


Assuntos
Comportamento Animal/fisiologia , Ingestão de Alimentos/fisiologia , Herpestidae/fisiologia , Predomínio Social , Animais , Feminino , Masculino , Dinâmica Populacional , Gravidez
2.
Curr Oncol ; 22(3): 199-210, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26089719

RESUMO

INTRODUCTION: The purpose of the present study was to investigate the efficacy of an ondansetron rapidly dissolving film (rdf) in the prophylaxis of radiation-induced nausea and vomiting (rinv). Rapidly dissolving film formulations facilitate drug delivery in circumstances in which swallowing the medication might be difficult for the patient. METHODS: Patients undergoing palliative radiotherapy at risk for rinv were prescribed ondansetron rdf 8 mg twice daily while on treatment and were asked to complete a nausea and vomiting-specific daily diary, the Functional Living Index-Emesis (flie), and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C15 Palliative (qlq-C15-pal). Patients were categorized as receiving primary or secondary prophylaxis based on whether they had already experienced emetic episodes. "Overall control" was defined as a maximum increase of 2 episodes of nausea or vomiting from baseline. "Acute phase" was defined as the days during radiation until the first day after radiation; "delayed phase" was defined as days 2-10 after radiation. RESULTS: The study accrued 30 patients. Rates of overall control for nausea and for vomiting during the acute phase in the primary prophylaxis group were 88% and 93% respectively; during the delayed phase, they were 73% and 75%. Rates of overall control for nausea and for vomiting during the acute phase in the secondary prophylaxis group were both 100%; during the delayed phase, they were 50%. The number of nausea and vomiting episodes was found to be significantly correlated with the flie and qlq-C15-pal questionnaires. CONCLUSIONS: Ondansetron rdf is effective for the prophylaxis of rinv.

3.
Nat Commun ; 5: 4499, 2014 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-25047446

RESUMO

In many animal societies, a small proportion of dominant females monopolize reproduction by actively suppressing subordinates. Theory assumes that this is because subordinate reproduction depresses the fitness of dominants, yet the effect of subordinate reproduction on dominant behaviour and reproductive success has never been directly assessed. Here, we describe the consequences of experimentally preventing subordinate breeding in 12 groups of wild meerkats (Suricata suricatta) for three breeding attempts, using contraceptive injections. When subordinates are prevented from breeding, dominants are less aggressive towards subordinates and evict them less often, leading to a higher ratio of helpers to dependent pups, and increased provisioning of the dominant's pups by subordinate females. When subordinate breeding is suppressed, dominants also show improved foraging efficiency, gain more weight during pregnancy and produce heavier pups, which grow faster. These results confirm the benefits of suppression to dominants, and help explain the evolution of singular breeding in vertebrate societies.


Assuntos
Herpestidae/fisiologia , Reprodução , Comportamento Sexual Animal , Agressão , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Evolução Biológica , Peso Corporal , Feminino , Masculino , Gravidez
4.
Curr Oncol ; 20(5): e396-405, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24155637

RESUMO

OBJECTIVE: We examined whether patterns of practice in the prescription of palliative radiation therapy for bone metastases had changed over time in the Rapid Response Radiotherapy Program (rrrp). METHODS: After reviewing data from August 1, 2005, to April 30, 2012, we analyzed patient demographics, diseases, organizational factors, and possible reasons for the prescription of various radiotherapy fractionation schedules. The chi-square test was used to detect differences in proportions between unordered categorical variables. Univariate logistic regression analysis and the simple Fisher exact test were also used to determine the factors most significant to choice of dose-fractionation schedule. RESULTS: During the study period, 2549 courses of radiation therapy were prescribed. In 65% of cases, a single fraction of radiation therapy was prescribed, and in 35% of cases, multiple fractions were prescribed. A single fraction of radiation therapy was more frequently prescribed when patients were older, had a prior history of radiation, or had a prostate primary, and when the radiation oncologist had qualified before 1990. CONCLUSIONS: For patients with bone metastasis, a single fraction of radiation therapy was prescribed with significantly greater frequency.

5.
Curr Oncol ; 20(3): e206-11, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23737690

RESUMO

OBJECTIVE: We set out to review the Rapid Response Radiotherapy Program (rrrp). METHODS: We retrospectively reviewed a prospective database of patients referred to the rrrp between August 1, 2008, and June 30, 2012, extracting patient demographics, case dispositions, and wait times in days from referral to consultation and from consultation to treatment. RESULTS: Of 2742 patients referred to the rrrp, 1458 (53%) were men, and 1284 (47%) were women. Median age was 64 years. The most prevalent primary cancer sites were lung (33%), breast (21%), and prostate (17%). The most common reasons for referral were bone metastases (53%) and brain metastases (21%). Palliative radiation therapy was given to 1890 patients. The median wait time from referral to consultation was 3 days. Among treated patients, 60% were treated on the day of their consultation, and 33%, within 1-6 days. CONCLUSIONS: The rrrp continues to deliver timely palliative radiation therapy to patients, comparable to earlier reviews. The continued success of the rrrp will remain a model for future rapid-access palliative radiation therapy clinics.

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