Speciation by host switch in brood parasitic indigobirds

A growing body of empirical and theoretical work supports the plausibility of sympatric speciation(1-3), but there remain few examples in which all the essential components of the process are well understood. The African indigobirds Vidua spp. are host-specific brood parasites. Indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts(4-6). As adults, male indigobirds mimic host song(4-7), whereas females use these songs to choose both their mates and the nests they parasitize(8). These behavioural mechanisms promote the cohesion of indigobird populations associated with a given host species, and provide a mechanism for reproductive isolation after a new host is colonized. Here we show that all indigobird species are similar genetically, but are significantly differentiated in both mitochondrial haplotype and nuclear allele frequencies. These data support a model of recent sympatric speciation. In contrast to the cuckoo Cuculus canorus, in which only female lineages are faithful to specific hosts(9,10), host switches have led to speciation in indigobirds because both males and females imprint on their hosts(8,11).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62510/1/nature01863.pd

Trends in body image of adolescent females in metropolitan and non-metropolitan regions: a longitudinal study

Abstract Background Body dissatisfaction is associated with a range of adverse outcomes, including impaired psychological health, low physical activity and disordered eating. This longitudinal study used the Factors Influencing Transitions in Girls’ Active Leisure and Sport (FITGALS) dataset to examine trends in body image of adolescent females. Specifically, the study examined satisfaction with body size, physical appearance and dieting behaviour for two cohorts at transitional life phases in two geographic regions longitudinally over a 3-year period. Methods A sample of 732 adolescent females in Grade 7 (n = 489, 66.8 %) and Grade 11 (n = 243, 33.2 %) at randomly selected Australian metropolitan and non-metropolitan secondary schools responded to a questionnaire in three successive years from 2008 to 2010. Participants reported perceptions about their body size and physical appearance and whether they were, or ought to be, on a diet. The data were analysed using a series of longitudinal logistic regression models. Results Dieting and dissatisfaction with body size significantly increased over time and more so for older than younger girls. Region significantly moderated the effect of grade level regarding dissatisfaction with body size but not dieting. In non-metropolitan regions, those in the younger cohort were significantly more likely to be dissatisfied with their body size than the older cohort; whereas in metropolitan regions, those in the older cohort were significantly more likely to be dissatisfied with their body size than the younger cohort. Adolescent female’s perceptions of their appearance were unchanged over time, region and grade level. Conclusions Differences across time, region and grade level were found among adolescent females on body size and dieting behaviour, but not physical appearance. Adolescent females experience early and increasing body size dissatisfaction and dieting as they age, but stable perceptions of physical appearance. Age and geographic region are important considerations for the timing and targeting of interventions to address body image concerns. Further investigation of regional differences in body image perceptions and factors that affect these is warranted. The findings of this study highlight the ongoing need for strategies during adolescence to promote a healthy appreciation of body size and appearance

Research into the practical and policy applications of soundscape concepts and techniques in urban areas

Executive Summary 1 The aim of this review was to investigate existing research into soundscape concepts and to produce recommendations for future research into the practical identification, management and enhancement of soundscapes in urban areas. 2 Existing research on soundscapes was investigated using four methods: i. a survey of more than 500 papers in the academic literature, ii. an analysis of 27 case studies of soundscape assessment, iii. an analysis of 15 case studies of soundscape design, and iv. interviews with five key soundscape experts. Analysis of this data was conducted to identify significant gaps in the knowledge base and suggest a way of obtaining a practical soundscape assessment method. 3 Soundscapes were found to be a highly multi-disciplinary topic, with many different ideas, concepts, aims and methods evident in the literature. The definition of the term soundscape is itself not settled; for the purposes of this project, we have defined it as “the totality of all sounds within a location with an emphasis on the relationship between individual’s or society’s perception of, understanding of and interaction with the sonic environment.” 4 This review highlights that a range of methodological approaches have been used to establish classifications and categorisations of sounds and soundscapes. The relationship between different categories of sounds and their interaction needs to be considered to increase the understanding of soundscape assessments and to derive soundscape classifications. 5 The different methods and tools used to assess soundscapes, in a variety of locations, each have advantages and disadvantages; using a number of methods in one case study can help to mitigate against the disadvantages of any one method. The case studies assessed in this report demonstrate the importance of individual and demographic similarities/differences, people’s behaviour, physical aspects of the soundscape, other sensory and environmental elements, and the general location and context, in understanding and assessing soundscapes. 6 Soundscape assessments involving a subjective component have highlighted a number of variables that play a part in the assessment. These include the individual’s knowledge and prior experience of the soundscape, the meaning they derive from it, their attitude towards the sound source, their behaviour, their noise sensitivity, demographic and cultural dimensions, and their sense of control over the noise. 7 Research has shown that sometimes a soundscape is perceived as a collection of the individual sounds of which it is comprised; soundscape assessments are therefore related to the assessment of those sound types. This implies that soundscape assessment relies upon the identification of the sounds, the prominence of the sounds, and potentially the ratio of certain sound types to other sound types within the soundscape. It is also highlighted that, because the soundscape varies over time, note must be taken of the fact that any soundscape assessment relates to a singular moment in time. Furthermore, research has shown that soundscape assessments can be dependent on an individual’s memory (when using subjective assessments methods) and/or the segment of the soundscape that was recorded (when playing back recorded soundscapes in a laboratory situation). 8 Multi-sensory experience is also shown to be highly relevant to soundscape assessment and must therefore be acknowledged as soundscapes are not perceived in sensory isolation; in particular audio-visual interactions have been shown to have an effect on soundscape perception. Many researchers point to the importance of understanding the full environmental and social context for soundscape assessment, the relevance of comparing similar place types, and the effect of moving between one soundscape and another on an assessment. 9 Turning to the subject of soundscape design, it is noted that there is a dearth of case studies involving the modification and design of soundscapes, both in the UK and internationally. The rationale behind many of the case studies’ focus upon or consideration of sound was the improvement of a soundscape that was negatively affected by the sound of traffic. Approaches to soundscape design varied, ranging from the use of noise control elements, such as barriers and absorbers, to the utilisation or exploitation of natural elements that already exist in the location. Some case studies introduced sounds to the soundscape, in particular water sounds, while others incorporated specific sonic art installations to alter the soundscape or detract attention from existing features of the soundscape. A number of case studies used design alterations to improve the soundscape and perception of the soundscape including altering visual aspects of the place, altering the layout of the area, pedestrianisation of the area, and providing entertainment facilities (e.g. cafes). 10 Case studies whereby design modifications or interventions have taken place, have had little or no formal evaluation of their success. The studies that were evaluated used a number of different methods involving both objective and subjective measures and included the experimental comparison of subjective ratings, observations of people’s behaviour, recognition and awards for good designs, and level of complaints about the soundscape. This demonstrates that different evaluation tools may be necessary dependent upon the type of soundscape intervention being evaluated. Additionally, by combining methods to produce an interdisciplinary evaluation, a more accurate understanding of the success of the soundscape design is possible, hence improving future interventions. 11 The relationship between environment and individual is complex, with many factors, some of which cannot currently be quantified. Important factors include: prominent individual sound sources, the interaction of sources, other sensory stimuli and contextual and individual factors such as meaning, and expectation. Some of these factors can be captured by subjective rating scales for high-level concepts like ‘calmness’, ‘vibrancy’ and ‘spaciousness’. Other factors, such as the semantic meaning of a soundscape are best characterised currently by qualitative descriptors. There are good prospects for developing objective acoustic metrics to evaluate some factors but in most cases this work is still at an early stage, and the methods developed so far have only been applied in specific contexts; to provide metrics that are more broadly applicable they would need to be evaluated in a broader range of locations and conditions. The expert interviews and case studies illustrated the diversity of views across different disciplines on the most promising soundscape methods. All the interviewees agreed on the need for an interdisciplinary approach, and on the need to retain some form of subjective rating when assessing soundscapes. 12 Ultimately, six important gaps have been identified in the soundscape knowledge base. These are areas where more research would significantly improve understanding soundscape assessments. These gaps have been identified as: i. a lack of genuinely interdisciplinary projects (characterised by a shared perspective) instead of multidisciplinary projects (where researchers work in parallel within their own disciplines). These are needed to deal with the multidimensional experience of soundscape perception. ii. a lack of basic knowledge on many aspects of soundscape cognition, perception and classification. iii.a need for large-scale robust field trials of soundscape assessment methods instead of the more common experiment of a new method in a single location. iv. a need to develop more soundscape-specific indicators and tools that could eventually be used for soundscape design. v. a need to rigorously assess deliberate soundscape interventions to understand which design aspects work and which do not. vi. a lack of a close connection between soundscape research, design and planning practice. 13 Finally, a new research project is proposed to develop a robust field assessment method. The aim of this project is to develop a method based on existing research methods but introducing greater confidence by trialling the method across many real urban soundscapes. Options are presented for developing a purely qualitative assessment tool or one that incorporates and integrates both qualitative and quantitative ratings. 14 We recommend that a first step for an assessment method, which could realistically be developed in the near future, should be based on qualitative methods. A second iteration of this soundscape assessment tool could supplement the qualitative techniques with quantitative methods, first based on subjective rating scales and eventually on objective metrics which predict the subjective ratings

Variations in Pastors’ Perceptions of the Etiology of Depression By Race and Religious Affiliation

Depression is a major, preventable problem in the United States, yet relatively few individuals seek care in traditional mental health settings. Instead, many choose to confide in friends, family, or clergy. Thus, it is important to discover how clergy perceive the definition of and etiology of depression. The author conducted a survey with 204 Protestant pastors in California. Multinomial logistic regression revealed a statistically significant difference in how depression is perceived based on race. Caucasian American pastors more readily agreed with the statement that depression was a biological mood disorder, while African American pastors more readily agreed that depression was a moment of weakness when dealing with trials and tribulations. Also, mainline Protestants more frequently disagreed with statements about spiritual causes of depression than Pentecostals and non-denominational pastors. The findings suggest that racial and religious affiliational influences shape how pastors view, and ultimately intervene, in the area of depression

Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador

Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era. Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact characteristics). Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission. Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees

Association and Interaction Analyses of GABBR1 and GABBR2 with Nicotine Dependence in European- and African-American Populations

Previous studies have demonstrated that the γ-aminobutyric acid type B (GABAB) receptor plays an essential role in modulating neurotransmitter release and regulating the activity of ion channels and adenyl cyclase. However, whether the naturally occurring polymorphisms in the two GABAB receptor subunit genes interact with each other to alter susceptibility to nicotine dependence (ND) remains largely unknown. In this study, we genotyped 5 and 33 single nucleotide polymorphisms (SNPs) for GABAB receptor subunit 1 and 2 genes (GABBR1, GABBR2), respectively, in a sample of 2037 individuals from 602 nuclear families of African- American (AA) or European-American (EA) origin. We conducted association analyses to determine (1) the association of each subunit gene with ND at both the individual SNP and haplotype levels and (2) the collective effect(s) of SNPs in both GABAB subunits on the development of ND. Several individual SNPs and haplotypes in GABBR2 were significantly associated with ND in both ethnic samples. Two haplotypes in AAs and one haplotype in EAs showed a protective effect against ND, whilst two other haplotypes in AAs and three haplotypes in EAs showed a risk effect for developing ND. Interestingly, these significant haplotypes were confined to two regions of GABBR2 in the AA and EA samples. Additionally, we found two minor haplotypes in GABBR1 to be positively associated with Heaviness of Smoking Index (HSI) in the EA sample. Finally, we demonstrated the presence of epistasis between GABBR1 and GABBR2 for developing ND. The variants of GABBR1 and GABBR2 are significantly associated with ND, and the involvement of GABBR1 is most likely through its interaction with GABBR2, whereas GABBR2 polymorphisms directly alter susceptibility to ND. Future studies are needed with more dense SNP coverage of GABBR1 and GABBR2 to verify the epistatic effects of the two subunit genes

Impairment in Activities of Daily Living and unmet need for care among older adults: A population-based study from Burkina Faso

OBJECTIVES: The importance of impairment in performing Activities of Daily Living (ADL) is likely to increase in sub-Saharan Africa since few care options for affected people exist. This study investigated the prevalence of ADL impairment, the extent to which care-need was met and described characteristics of people with ADL impairment and unmet need in Burkina Faso. METHODS: This study used data from the CRSN Heidelberg Aging Study, a population-based study among 3,026 adults aged over 40 years conducted in rural Burkina Faso. Information on six basic ADL items was sought, with a follow-up question asking whether care-needs were not met, partially met or met. Bivariable correlations and multivariable logistic regression were used to determine sociodemographic and health characteristics associated with ADL impairment and unmet need. RESULTS: ADL impairment of any kind was reported by 1,202 (39.7%) respondents and was associated with older age (Adjusted Odds Ratio: 1.05 [95% CI: 1.04-1.06]), being a woman (1.33 [1.06-1.60]) and reporting depressive symptoms (1.90 [1.65-2.18]). Among those with ADL impairment, 67.8% had at least one unmet need. Severe ADL impairment was found in 202 (6.7%) respondents, who reported lower prevalence of unmet need (43.1%). Severe ADL impairment was associated with depressive symptoms (2.55 [2.11-3.07]) to a stronger degree than any ADL impairment. DISCUSSION: Prevalence of ADL impairment and unmet need was high in this setting. Variation in impairment across the population highlighted key groups for future interventions. Unmet need for care was highest in middle-aged adults, indicating a gap in care provision

Electronic structure of superconducting graphite intercalate compounds: The role of the interlayer state

Although not an intrinsic superconductor, it has been long--known that, when intercalated with certain dopants, graphite is capable of exhibiting superconductivity. Of the family of graphite--based materials which are known to superconduct, perhaps the most well--studied are the alkali metal--graphite intercalation compounds (GIC) and, of these, the most easily fabricated is the C${}_8$K system which exhibits a transition temperature $\bm{T_c\simeq 0.14}$K. By increasing the alkali metal concentration (through high pressure fabrication techniques), the transition temperature has been shown to increase to as much as $\bm 5$K in C${}_2$Na. Lately, in an important recent development, Weller \emph{et al.} have shown that, at ambient conditions, the intercalated compounds \cyb and \cca exhibit superconductivity with transition temperatures $\bm{T_c\simeq 6.5}$K and $\bm{11.5}$K respectively, in excess of that presently reported for other graphite--based compounds. We explore the architecture of the states near the Fermi level and identify characteristics of the electronic band structure generic to GICs. As expected, we find that charge transfer from the intercalant atoms to the graphene sheets results in the occupation of the $\bm\pi$--bands. Yet, remarkably, in all those -- and only those -- compounds that superconduct, we find that an interlayer state, which is well separated from the carbon sheets, also becomes occupied. We show that the energy of the interlayer band is controlled by a combination of its occupancy and the separation between the carbon layers.Comment: 4 Figures. Please see accompanying experimental manuscript "Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca" by Weller et a

Bioenergetic model sensitivity to diet diversity across space, time and ontogeny

Consumption is the primary trophic interaction in ecosystems and its accurate estimation is required for reliable ecosystem modeling. When estimating consumption, species' diets are commonly assumed to be the average of those that occur among habitats, seasons, and life stages which introduces uncertainty and error into consumption rate estimates. We present a case study of a teleost (Yellowfin Bream Acanthopagrus australis) that quantifies the potential error in consumption (in mass) and growth rate estimates when using diet data from different regions and times and ignoring ontogenetic variability. Ontogenetic diet trends were examined through gut content analysis (n = 1,130 fish) and incorporated into a bioenergetic model (the "primary " model) that included diet variability (n = 144 prey sources) and ontogenetic changes in metabolism (1-7 year) to estimate lifetime consumption. We quantified error by building nine model scenarios that each incorporated different spatiotemporal diet data of four published studies. The model scenarios produced individual lifetime consumption estimates that were between 25% lower and 15% higher than the primary model (maximum difference was 53%, range 11.7-17.8 kg). When consumption (in mass) was held constant, differences in diet quality among models caused a several-fold range in growth rate (0.04-1.07 g day(-1)). Our findings showcase the large uncertainty in consumption rate estimates due to diet diversity, and illustrate that caution is required when considering bioenergetic results among locations, times, and ontogeny

Plutonium transfer to wildlife at legacy sites

When internalized within an organism’s body, plutonium (Pu) can be important in dose calculation due to its relatively high-energy alpha emissions (~5-6 MeV). In this paper we quantify transfer of Pu to a range of wildlife types at legacy nuclear weapons sites and evaluate the importance of body tissue Pu distribution in the transfer of Pu through the food chain. The paper presents new data from Maralinga, Australia, as well as past data from terrestrial and marine settings of the US nuclear research program