985 research outputs found

    Skew in ovarian activation depends on domicile size in phyllode-glueing thrips

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    Costs and benefits of group living are a fundamental topic in behavioural ecology. Resource availability affects individuals’ breeding prospects alone and in groups, as well as how reproduction is distributed within groups (“reproductive skew”). Here, we provide correlational evidence in facultatively social thrips that breeding resources are associated with (1) whether solitary or social living is favoured, and (2) the degree of ovarian skew. Dunatothrips aneurae (Thysanoptera, Phlaeothripidae) cooperatively build silk “domiciles” on Australian Acacias, feeding exclusively from internal phyllode surfaces. Per capita productivity scaled differently with group size depending on domicile volume - females in small domiciles did better alone than in groups, whereas in large domiciles single and group-nesting females did equally well. Ovarian dissections revealed that in small domiciles some females were nonreproductive, indicating ovarian (i.e. reproductive) skew. Skew increased as domicile size decreased and group size increased. Breeders had smaller oocyte volume in smaller domiciles, especially those containing nonreproductives. These findings suggest group formation and reproductive skew in D. aneurae may be influenced by reproductive competition for breeding resources. Nonreproductive females in small domiciles may be reproductively suppressed, subfertile, or accumulating resources to reproduce

    Academic chartered data safety committees versus industry sponsored data safety committees: The need for different recommendations

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    Dear Editor, We read with great interest the recently published paper by Calis et al.1 We applaud the authors and the working group for developing this important set of recommendations for data monitoring committees (DMC). Recommendations for organizing a DMC are long overdue. Our academic institution has had a formal DMC for many years which administratively reports to an academic official who directs the research efforts. It has a formal charter and broad membership that includes clinicians, clinical trial specialists, and a biostatistician. It accepts for review studies that require a DMC (usually phase II or III trials) and are not sponsored by industry, which usually set up their own DMC. Most studies are supported by the institution, US Government research funding sources (e.g. National Institutes of Health (NIH), Centers for Disease Control and Prevention), or research foundations

    Discovery of a redshift 6.13 quasar in the UKIRT infrared deep sky survey

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    Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO) DOI: 10.1051/0004-6361/200811161Optical and near-infrared (NIR) spectra are presented for ULAS J131911.29+095051.4 (hereafter ULAS J1319+0950), a new redshift z = 6.127 0.004 quasar discovered in the Third Data Release (DR3) of the UKIRT Infrared Deep Sky Survey (UKIDSS). The source has = 19.10 0.03, corresponding to = -27.12, which is comparable to the absolute magnitudes of the z 6 quasars discovered in the Sloan Digital Sky Survey (SDSS). ULAS J1319+0950 was, in fact, registered by SDSS as a faint source with = 20.13 0.12, just below the signal-to-noise ratio limit of the SDSS high-redshift quasar survey. The faint z-band magnitude is a consequence of the weak Ly /N V emission line, which has a rest-frame equivalent width of ~20Å and provides only a small boost to the z-band flux. Nevertheless, there is no evidence of a significant new population of high-redshift quasars with weak emission lines from this UKIDSS-based search. The Ly  optical depth to ULAS J1319+0950 is consistent with that measured towards similarly distant SDSS quasars, implying that results from optical- and NIR-selected quasars may be combined in studies of cosmological reionization. Also presented is a new NIR-spectrum of the previously discovered UKIDSS quasar ULAS J020332.38+001229.2, which reveals the object to be a broad absorption line quasar. The new spectrum shows that the emission line initially identified as Ly  is actually N V, leading to a revised redshift of z = 5.72, rather than z = 5.86 as previously estimatedPeer reviewe

    Where does prepotency come from on developmental tests of inhibitory control?

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    Understanding the processes that make responses prepotent is central to understanding the role of inhibitory control in cognitive development. The question of what makes responses prepotent was investigated using the two most widely studied measures of preschoolers' inhibitory control. Across two experiments, 80 children were tested either on a series of stimulus-response compatibility (SRC) tasks or on a series of Go/No-go tasks. Results indicated that high levels of prepotency on SRC tasks (such as the Day/Night task) occur only under specific conditions; making a verbal response can be highly prepotent if the stimulus and response are associated with each other (e.g., saying "cup" to a cup) but is less prepotent when they are unassociated (e.g., saying "cup" to a doorstop). Action responses (e.g., lifting a cup to your mouth) show little prepotency irrespective of whether the stimulus and response are associated. In contrast, with Go/No-go tasks, a much wider variety of behaviors are highly prepotent regardless of whether the stimulus and response are associated. These data suggest that prepotency arises in very different ways, depending on the type of task used. Although both Go/No-go tasks and SRC tasks can make inhibitory demands, they do so for fundamentally different reasons

    Can we boost preschoolers’ inhibitory performance just by changing the way they respond?

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    Changing the way children make their response appears to sometimes, but not always, boost their inhibitory control—though interpreting existing findings is hampered by inconsistent methods and results. This study investigated the effects of delaying, and changing, the means of responding. Ninety-six preschoolers (Mage 46 months) completed tasks assessing inhibitory control, counterfactual reasoning, strategic reasoning, and false belief understanding. Children responded either immediately or after a delay, and either by pointing with their finger, or with a hand-held arrow. Delaying boosted performance on all tasks except false belief understanding; arrow-pointing only improved strategic reasoning. It is suggested that delay helps children work out the correct response; it is unlikely to help on tasks where this requirement is absent

    Epidemiology of atopic dermatitis in adults: Results from an international survey.

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    Background:There are gaps in our knowledge of the prevalence of adult atopicdermatitis (AD).Objective:To estimate the prevalence of AD in adults and by disease severity.Methods:This international, cross-sectional, web-based survey was performed inthe United States, Canada, France, Germany, Italy, Spain, United Kingdom, andJapan. Adult members of online respondent panels were sent a questionnaire forAD identification and severity assessment; demographic quotas ensured populationrepresentativeness for each country. A diagnosis of AD required subjects to be posi-tive on the modified UK Working Party/ISAAC criteriaandself-report of ever hav-ing an AD diagnosis by a physician. The proportion of subjects with AD whoreported being treated for their condition was determined and also used to estimateprevalence. Severity scales were Patient-Oriented SCORAD, Patient-OrientatedEczema Measure, and Patient Global Assessment.Results:Among participants by region, the point prevalence of adult AD in the over-all/treated populations was 4.9%/3.9% in the US, 3.5%/2.6% in Canada, 4.4%/3.5% inthe EU, and 2.1%/1.5% in Japan. The prevalence was generally lower for males vsfemales, and decreased with age. Regional variability was observed within countries.Severity varied by scale and region; however, regardless of the scale or region, propor-tion of subjects reporting severe disease was lower than mild or moderate disease.Conclusions:Prevalence of adult AD ranged from 2.1% to 4.9% across countries.Severe AD represented a small proportion of the overall AD population regardlessof measure or region

    Adult beginner distance language learner perceptions and use of assignment feedback

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    This qualitative study examines perceptions and use of assignment feedback among adult beginner modern foreign language learners on higher education distance learning courses. A survey of responses to feedback on assignments by 43 Open University students on beginner language courses in Spanish, French, and German indicated that respondents can be classified into three groups: those who use feedback strategically by integrating it into the learning process and comparing it with, for example, informal feedback from interaction with native speakers, those who take note of feedback, but seem not to use it strategically, and those who appear to take little account of either marks or feedback. The first group proved to be the most confident and most likely to maintain their motivation in the longer term. The conclusion discusses some of the pedagogical and policy implications of the findings

    Assessment of hydropyrolysis as a method for the quantification of black carbon using standard reference materials

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    A wide selection of thermal, chemical and optical methods have been proposed for the quantification of black carbon (BC) in environmental matrices, and the results to date differ markedly depending upon the method used. A new approach is hydropyrolysis (hypy), where pyrolysis assisted by high hydrogen pressures (150 bar) facilitates the complete reductive removal of labile organic matter, so isolating a highly stable portion of the BC continuum (defined as BChypy). Here, the potential of hypy for the isolation and quantification of BC is evaluated using the 12 reference materials from the International BC Ring Trial, comprising BC-rich samples, BC-containing environmental matrices and BC-free potentially interfering materials. By varying the hypy operating conditions, it is demonstrated that lignocellulosic, humic and other labile organic carbon material (defined as non-BChypy) is fully removed by 550 °C, with hydrogasification of the remaining BChypy not commencing until over 575 °C. The resulting plateau in sample mass and carbon loss is apparent in all of the environmental samples, facilitating BC quantification in a wide range of materials. The BChypy contents for all 12 ring trial samples fall within the range reported in the BC inter-comparison study, and systematic differences with other methods are rationalised. All methods for BC isolation, including hypy are limited by the fact that BC cannot be distinguished from extremely thermally mature organic matter; for example in high rank coals. However, the data reported here indicates that BChypy has an atomic H/C ratio of less than 0.5 and therefore comprises a chemically well-defined polyaromatic structure in terms of the average size of peri-condensed aromatic clusters of >7 rings (24 carbon atoms), that is consistent across different sample matrices. This, together with the sound underlying rationale for the reductive removal of labile organic matter, makes hypy an ideal approach for matrix independent BC quantification. The hypy results are extremely reproducible, with BChypy determinations from triplicate analyses typically within ±2% across all samples, limited mainly by the precision of the elemental analyser
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