272 research outputs found
Astaxanthin is responsible for the pink plumage flush of Franklins and Ring-billed gulls
ABSTRACT. Carotenoid pigments produce the red, orange, and yellow plumage of many birds. Carotenoidcontaining feathers are typically rich in color and displayed by all adult members of the species. In many gulls and terns, however, an unusual light pink coloring (or flush) to the normally white plumage can be found in highly variable proportions within and across populations. The carotenoid basis of plumage flush was determined in an Elegant Tern (Sterna elegans; Hudon and Brush 1990), but it is not clear if all larids use this same mechanism for pink plumage coloration. We examined the carotenoid content of pink feathers in Franklin's (Larus pipixcan) and Ring-billed (Larus delawarensis) gulls and found that a single carotenoid-astaxanthin-was present. Astaxanthin was primarily responsible for the flush in Elegant Terns as well, but was accompanied by other carotenoids (e.g., canthaxanthin and zeaxanthin), as is typical of most astaxanthin-containing bird feathers. In both gull and tern species, carotenoids were contained within feathers and did not occur on the plumage surface in preen oil, as some have previously speculated. We hypothesize that some gulls turn pink because they acquire unusually high amounts of astaxanthin in their diets at the time of feather growth. It is tempting to link the increase in sightings of pink Ringbilled Gulls since the late 1990s with the introduction of pure, synthetic astaxanthin to the diets of hatchery-raised salmon. SINOPSIS. Astaxantina, responsible del plumaje Rosado en Larus pixpican y Larus delawarensis Los pigmentos carotenoides son los responsables de la coloración roja, anaranjada y amarilla en el plumaje de aves. Plumas que contienen carotenoides, generalmente son ricas en color y son mostradas en variados patrones de conducta por los adultos con dicha coloración. No obstante, en muchas gaviotas se puede observar una coloración rosada, en vez del típico plumaje blanco y su proporción puede ser variable en una o entre poblaciones. La presencia de carotenoides, y plumaje rosado, fue documentado en Sterna elegans, pero no quedo claro, si el mismo tipo de mecanismo aplica a otros laridos. Examinamos el contenido carotenoides en plumas rosadas de las gaviotas, Larus pixpican y L. delawarensis, y encontramos que la presencia de astaxantina. Este mismo carotenoide fue el principal responsable de la coloración rosada en Sterna elegans, sin embargo estuvo acompañado de otros carotenoides (ej. cantaxantina y seazantina). En las diferentes gaviotas estudiadas se encontró que los carotenoides se encontraban dentro de la pluma y no presentes en la superficie de estas o en el aceite de la glándula uropigial, como se había previamente especulado. Nuestra hipótesis es que algunas gaviotas adquieren un plumaje rosado a consecuencia de la dieta ingerida durante el periodo de crecimiento de las plumas. Es tentador tratar de atar el color rosado en gaviotas como L. delawarensis a partir del 1990 con la introducción de astaxantina sintética en la dieta de salmones criados en cautiverio
Role of Farmer Knowledge in Agroecosystem Science: Rice Farming and Amphibians in the Philippines
Rice (Oryza sativa) agriculture provides food and economic security for nearly half of the world’s population. Rice agriculture is intensive in both land and agrochemical use. However, rice fields also provide aquatic resources for wildlife, including amphibians. In turn, some species may provide ecosystem services back to the farmers working in the rice agroecosystem. The foundation for understanding the complexity of agroecosystem–human relationships requires garnering information regarding human perceptions and knowledge of the role of biodiversity in these rice agroecosystems. Understanding farmer knowledge and perceptions of the ecosystem services provided by wildlife in their fields, along with their understanding of the risks to wildlife associated with agrochemical exposure, can inform biodiversity preservation efforts. In June and July 2014, we used focus groups and structured and semi-structured interviews that engaged 22 individuals involved in rice agriculture operations in Laguna, Philippines, a village close to the International Rice Research Institute in Los Baños, Philippines, to learn more about farmer perceptions and knowledge of amphibians in their rice fields. We found that many, though not all farm workers (managers, tenants, and laborers) noted declines in amphibian populations over time, expressed how they incorporated frogs and toads (Anura) into their daily lives, and recognized the value of amphibians as ecosystem service providers. Specifically, farmers noted that amphibians provide pest-management through consumption of rice pests, act as biomonitors for pesticide-related health outcomes, and provide a local food and economic resource. Some farmers and farm workers noted the general cultural value of listening to the “frogs sing when it rains.” Overall, our findings demonstrate that farmers have an understanding of the value of amphibians in their fields. Future efforts can support how engagement with farmers and farm workers to evaluate the value of wildlife in their fields can lead to directed education efforts to support biodiversity conservation in agroecosystems
The impact of competition on elephant musth strategies: a game–theoretic model
Mature male African Savannah elephants are known to periodically enter a temporary state of heightened aggression called “musth,” often linked with increased androgens, particularly testosterone. Sexually mature males are capable of entering musth at any time of year, and will often travel long distances to find estrous females. When two musth bulls or two non-musth bulls encounter one another, the agonistic interaction is usually won by the larger male. However, When a smaller musth bull encounters a larger non-musth bull, the smaller musth male can win. The relative mating success of musth males is due partly to this fighting advantage, and partly to estrous females’ general preference for musth males.
Though musth behavior has long been observed and documented, the evolutionary advantages of musth remain poorly understood. Here we develop a game–theoretic model of male musth behavior which assumes musth duration as a parameter, and distributions of small, medium and large musth males are predicted in both time and space. The predicted results are similar to the musth timing behavior observed in the Amboseli National Park elephant population, and further results are generated with relevance to Samburu National Park. We discuss small male musth behavior, the effects of estrous female spatial heterogeneity on musth timing, conservation applications, and the assumptions underpinning the model
Fundamental movement skills are more than run, throw and catch: The role of stability skills.
Introduction In motor development literature fundamental movement skills are divided into three constructs: locomotive, object control and stability skills. Most fundamental movement skills research has focused on children's competency in locomotor and object control skills. The first aim of this study was to validate a test battery to assess the construct of stability skills, in children aged 6 to 10 (M age = 8.2, SD = 1.2). Secondly we assessed how the stability skills construct fitted into a model of fundamental movement skill. Method The Delphi method was used to select the stability skill battery. Confirmatory factor analysis (CFA) was used to assess if the skills loaded onto the same construct and a new model of FMS was developed using structural equation modelling. Results Three postural control tasks were selected (the log roll, rock and back support) because they had good face and content validity. These skills also demonstrated good predictive validity with gymnasts scoring significantly better than children without gymnastic training and children from a high SES school performing better than those from a mid and low SES schools and the mid SES children scored better than the low SES children (all p < .05). Inter rater reliability tests were excellent for all three skills (ICC = 0.81, 0.87, 0.87) as was test retest reliability (ICC 0.87-0.95). CFA provided good construct validity, and structural equation modelling revealed stability skills to be an independent factor in an overall FMS model which included locomotor (r = .88), object control (r = .76) and stability skills (r = .81). Discussion This study provides a rationale for the inclusion of stability skills in FMS assessment. The stability skills could be used alongside other FMS assessment tools to provide a holistic assessment of children's fundamental movement skills. Copyright
Mitochondrial Data in Monocot Phylologenetics
Mitochondrial sequences are an important source of data in animal phylogenetics, equivalent in importance to plastid sequences in plants. However, in recent years plant systematists have begun exploring the mitochondrial genome as a source of phylogenetically useful characters. The plant mitochondrial genome is renowned for its variability in size, structure, and gene organization, but this need not be of concern for the application of sequence data in phylogenetics. However, the incorporation of reverse transcribed mitochondrial genes ( processed paralogs ) and the recurring transfer of genes from the mitochondrion to the nucleus are evolutionary events that must be taken into account. RNA editing of mitochondrial genes is sometimes considered a problem in phylogenetic reconstruction, but we regard it only as a mechanism that may increase variability at edited sites and change the codon position bias accordingly. Additionally, edited sites may prove a valuable tool in identifying processed paralogs. An overview of genes and sequences used in phylogenetic studies of angiosperms is presented. In the monocots, a large amount of mitochondrial sequence data is being collected together with sequence data from plastid and nuclear genes, thus offering an opportunity to compare data from different genomic compartments. The mitochondrial and plastid data are incongruent when organelle gene trees are reconstructed. Possible reasons for the observed incongruence involve sampling of paralogous sequences and highly divergent substitution rates, potentially leading to longbranch attraction. The above problems are addressed in Acorales, Alismatales, Poales, Liliaceae, the Anthericum clade (in Agavaceae), and in some achlorophyllous taxa
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Repeat prenatal corticosteroid prior to preterm birth: a systematic review and individual participant data meta-analysis for the PRECISE study group
The aim of this individual participant data (IPD) meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol. The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE) Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants are eligible for the PRECISE IPD meta-analysis. The primary study outcomes for the infants will be serious neonatal outcome (defined by the PRECISE International IPD Study Group as one of death (foetal, neonatal or infant); severe respiratory disease; severe intraventricular haemorrhage (grade 3 and 4); chronic lung disease; necrotising enterocolitis; serious retinopathy of prematurity; and cystic periventricular leukomalacia); use of respiratory support (defined as mechanical ventilation or continuous positive airways pressure or other respiratory support); and birth weight (Z-scores). For the children, the primary study outcomes will be death or any neurological disability (however defined by trialists at childhood follow up and may include developmental delay or intellectual impairment (developmental quotient or intelligence quotient more than one standard deviation below the mean), cerebral palsy (abnormality of tone with motor dysfunction), blindness (for example, corrected visual acuity worse than 6/60 in the better eye) or deafness (for example, hearing loss requiring amplification or worse)). For the women, the primary outcome will be maternal sepsis (defined as chorioamnionitis; pyrexia after trial entry requiring the use of antibiotics; puerperal sepsis; intrapartum fever requiring the use of antibiotics; or postnatal pyrexia). Data analyses are expected to commence in 2011 with results publicly available in 2012
Genetic risk for neurodegenerative disorders, and its overlap with cognitive ability and physical function
Neurodegenerative disorders are associated with impaired cognitive function and worse physical health outcomes. This study aims to test whether polygenic risk for Alzheimer’s disease, Amyotrophic Lateral Sclerosis (ALS), or frontotemporal dementia (FTD) is associated with cognitive function and physical health in the UK Biobank, a cohort of healthy individuals. Group-based analyses were then performed to compare the top and bottom 10% for the three neurodegenerative polygenic risk scores; these groups were compared on the cognitive and physical health variables. Higher polygenic risk for AD, ALS, and FTD was associated with lower cognitive performance. Higher polygenic risk for FTD was also associated with increased forced expiratory volume in 1s and peak expiratory flow. A significant group difference was observed on the symbol digit substitution task between individuals with high polygenic risk for FTD and high polygenic risk for ALS. The results suggest some overlap between polygenic risk for neurodegenerative disorders, cognitive function and physical health
Smoking cessation advice recorded during pregnancy in United Kingdom primary care
Background: United Kingdom (UK) national guidelines recommend that all pregnant women who smoke should be advised to quit at every available opportunity, and brief cessation advice is an efficient and cost-effective means to increase quit rates. The Quality and Outcomes Framework (QOF) implemented in 2004 requires general practitioners to document their delivery of smoking cessation advice in patient records. However, no specific targets have been set in QOF for the recording of this advice in pregnant women. We used a large electronic primary care database from the UK to quantify the pregnancies in which women who smoked were recorded to have been given smoking cessation advice, and the associated maternal characteristics.
Methods: Using The Health Improvement Network database we calculated annual propotions of pregnant smokers between 2000 and 2009 with cessation advice documented in their medical records during pregnancy. Logistic regression was used to assess variation in the recording of cessation advice with maternal characteristics.
Results: Among 45,296 pregnancies in women who smoked, recorded cessation advice increased from 7% in 2000 to 37% in 2004 when the QOF was introduced and reduced slightly to 30% in 2009. Pregnant smokers from the youngest age group (15–19) were 21% more likely to have a record of cessation advice compared to pregnant smokers aged 25–29 (OR 1.21, 95% CI 1.10-1.35) and pregnant smokers from the most deprived group were 38% more likely to have a record for cessation advice compared to pregnant smokers from the least deprived group (OR 1.38, 95% CI 1.14-1.68). Pregnant smokers with asthma were twice as likely to have documentation of cessation advice in their primary care records compared to pregnant smokers without asthma (OR 1.97, 95% CI 1.80-2.16). Presence of comorbidities such as diabetes, hypertension and mental illness also increased the likelihood of having smoking cessation advice recorded. No marked variations were observed in the recording of cessation advice with body mass index.
Conclusion: Recorded delivery of smoking cessation advice for pregnant smokers in primary care has increased with some fluctuation over the years, especially after the implementation of the QOF, and varies with maternal characteristics
Oncogenic CagA Promotes Gastric Cancer Risk via Activating ERK Signaling Pathways: A Nested Case-Control Study
Background: CagA cellular interaction via activation of the ERK signaling pathway may be a starting point in the development of gastric cancer. This study aimed to evaluate whether genes involved in ERK downstream signaling pathways activated by CagA are susceptible genetic markers for gastric cancer. Methods: In the discovery phase, a total of 580 SNPs within +/-5 kbp of 30 candidate genes were genotyped to examine an association with gastric cancer risk in the Korean Multi-center Cancer Cohort (100 incident gastric cancer case-control sets). The most significant SNPs (raw or permutated p value??0.02) identified in the discovery analysis were re-evaluated in the extension phase using unconditional logistic regression model (400 gastric cancer case-control sets). Combined analyses including pooled-and meta-analysis were conducted to summarize all the results. Results: 24 SNPs in eight genes (ERK, Dock180, C3G, Rap1, Src, CrkL, Mek and Crk) were significantly associated with gastric cancer risk in the individual SNP analyses in the discovery phase (p??0.05). In the extension analyses, ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 showed marginally significant gene-dose effects for gastric cancer. Consistently, final combined analysis presented the SNPs as significantly associated with gastric cancer risk (OR = 1.56, [95% CI: 1.19-2.06], OR = 0.61, [95% CI: 0.43-0.87], OR = 0.59, [95% CI: 0.54-0.76], respectively). Conclusions: Our findings suggest that ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 are genetic determinants in gastric carcinogenesis
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