1,583 research outputs found
Indirect genetic effects clarify how traits can evolve even when fitness does not
Acknowledgmenets We thank Cortland Griswold, Loeske Kruuk, Alastair Wilson, Piter Bijma, Lucas Marie-Orleach, Joel McGlothlin, and an anonymous reviewer for comments and discussions that helped to improve this manuscript. The authors declare no conflicts of interest.Peer reviewedPublisher PD
Negotiating the female successor-leader role within family business succession in China
This article explores the approaches of identity construction used by Chinese daughters while negotiating the successor–leader role within family businesses. A qualitative interpretivist approach was adopted to understand daughter views on gender, family business leadership and succession, as well as the approaches adopted to negotiate the role of female successor/leader in the Chinese family business. Twenty semi-structured interviews were conducted with both actual and potential female successors. Three approaches of identity construction emerged based on the degree of conformity to traditional gender roles and Confucian family values: first, to abide by conventional gender expectations and perceive themselves as a temporary leader; second, to act as the ‘second leader’ and remain involved in decision making and third, to challenge conventional gender roles and strive to be an independent leader. This article contributes to debates on women in family business and gendered identity construction of daughters in family business in the Chinese context
Kinetic Study of Ni and NiO Reactions Pertinent to the Earth’s Upper Atmosphere
Nickel atoms are injected into the Earth’s mesosphere by meteoric ablation, producing a Ni layer between 70 and 105 km in altitude. The subsequent reactions of Ni and NiO with atmospherically relevant species were studied using the time-resolved pulsed laser photolysis-laser-induced fluorescence technique, combined with electronic structure calculations and RRKM theory where appropriate. Results for bimolecular reactions (in cm3 molecule–1 s–1): k(Ni + O3, 293 K) = (6.5 ± 0.7) × 10–10; k(NiO + O3 → Ni + 2O2, 293 K) = (1.4 ± 0.5) × 10–10; k(NiO + O3 → NiO2 + O2, 293 K) = (2.5 ± 0.7) × 10–10; k(NiO + CO, 190–377 K) = (3.2 ± 0.6) × 10–11 (T/200)−0.19±0.05. For termolecular reactions (in cm6 molecule–2 s–1, uncertainty ± σ over the stated temperature range): log10(krec,0(Ni + O2 + N2, 190–455 K)) = −37.592 + 7.168log10(T) - 1.5650(log10(T))2, σ = 11%; log10(krec,0(NiO + O2 + N2, 293–380 K)) = −41.0913 + 10.1064log10(T) – 2.2610(log10(T))2, σ = 22%; and log10(krec,0(NiO + CO2 + N2, 191–375 K)) = −41.4265 + 10.9640log10(T) – 2.5287(log10(T))2, σ = 15%. The faster recombination reaction NiO + H2O + N2, which is clearly in the falloff region over the experimental pressure range (3–10 Torr), is best described by log10(krec,0/cm6 molecule–2 s–1) = −29.7651 + 5.2064log10(T) – 1.7118(log10(T))2, krec,∞ = 6.0 × 10–10 exp(−171/T) cm3 molecule–1 s–1, broadening factor Fc = 0.84, σ = 16%. The implications of these results in the atmosphere are then discussed
Comparison of fouling between aerobic and anaerobic MBR treating municipal wastewater
The key driver for anaerobic membrane bioreactors (AnMBR) for municipal wastewater treatment is enabling the transition to energy neutral wastewater treatment. However, municipal wastewater delivers a comparatively constrained methane yield, which means energy conservation must be prioritised to achieve the proposed energy neutral ambition. A critical focus on membrane fouling is therefore warranted, as membrane operation represents the primary energy demand in MBRs. This review seeks to quantify the characteristics of the prevailing AnMBR biological suspension and to ascertain whether knowledge transfer exists between fouling characteristics in aerobic and anaerobic MBRs for municipal applications. Analysis of literature data revealed that the level of extractable extracellular polymeric substrate is slightly higher in aerobic MBRs than in anaerobic MBRs. However, AnMBR comprises considerably higher soluble microbial product concentrations, which have been widely reported to increase fouling propensity in aerobic systems. More distinct is the difference in the colloidal and fine solids fraction (between 1 and 10–15 μm), which is likely to dominate fouling in anaerobic systems and limit knowledge transfer from aerobic MBRs. Literature data on energy production was compared to that employed for membrane operation, and evidences that despite the challenging character of the particle matrix, energy neutral operation is achievable for AnMBR applied to municipal wastewater treatment
Changing epidemiology of methicillin-resistant Staphylococcus aureus colonization in paediatric intensive-care units
Community-associated methicillin-resistant S. aureus (CA-MRSA) accounts for a growing proportion of hospital-onset infections, and colonization is a risk factor. This study aimed to determine changes in the prevalence of CA-MRSA colonization in paediatric intensive-care units (ICUs). A total of 495 paediatric patients colonized with MRSA from neonatal, medical, surgical, and cardiac ICUs between 2001 and 2009 were identified. Isolates were characterized by spa type, staphylococcal cassette chromosome (SCC) mec type and the presence of the genes encoding Panton–Valentine leukocidin (PVL). The proportion of patients colonized with MRSA remained stable (average 3·2%). The proportion of isolates with spa type 1, SCCmec type IV and PVL increased over time to maximums in 2009 of 36·1% (P < 0·001), 54·2% (P = 0·03) and 28·9% (P = 0·003), respectively. Antibiotic susceptibility patterns showed increasing proportions susceptible to clindamycin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole (P values <0·001). In conclusion, the proportion of MRSA-colonized children in ICUs with CA-MRSA increased significantly over time
Monopile foundation stiffness estimation of an instrumented offshore wind turbine through model updating
Rapid development of offshore wind foundation models has resulted in a large number of built structures with generally underestimated foundation stiffness properties and a need to update and validate both the individual structural models and the underlying foundation design frameworks. This paper outlines a structural health monitoring approach, based on the combination of output only structural health monitoring methods and model updating, to estimate foundation stiffness parameters using field monitored data. Field monitoring data from an offshore wind turbine under idling conditions, over a large monitoring period, are presented and operational modal analysis is applied to estimate the modal parameters. Those are compared to modal properties predicted by finite element models, employing either old (API/DNVGL) or new (PISA) foundation design properties, which are calibrated using geotechnical site investigation data. A new approach to interpret seabed level statically equivalent foundation stiffness, in terms of effective lateral and rotational stiffness against load eccentricity, is presented. Seabed level statically equivalent foundation properties are updated by comparison against the observed modal behaviour and the optimised foundation parameters are presented, demonstrating a close match to the predictions of the PISA method
The effectiveness of anaerobic digestion in removing estrogens and nonylphenol ethoxylates
This is the post-print version of the final paper published in Journal of Hazardous Materials. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.The fate and behaviour of two groups of endocrine disrupting chemicals, steroid estrogens and nonylphenol ethoxylates, have been evaluated during the anaerobic digestion of primary and mixed sewage sludge under mesophilic and thermophilic conditions. Digestion occurred over six retention times, in laboratory scale reactors, treating sludges collected from a sewage treatment works in the United Kingdom. It has been established that sludge concentrations of both groups of compounds demonstrated temporal variations and that concentrations in mixed sludge were influenced by the presence of waste activated sludge as a result of transformations during aerobic treatment. The biodegradation of total steroid estrogens was >50% during primary sludge digestion with lower removals observed for mixed sludge, which reflected bulk organic solids removal efficiencies. The removal of nonylphenol ethoxylates was greater in mixed sludge digestion (>58%) compared with primary sludge digestion and did not reflect bulk organic removal efficiencies. It is apparent that anaerobic digestion reduces the concentrations of these compounds, and would therefore be expected to confer a degree of protection against exposure and transfer of both groups of compounds to the receiving/re-use environment.Thames Water, Yorkshire Water, and EPSRC
HLA-A, -B, -C, -DRB1, DRB3, DRB4, DRB5 and DQB1 polymorphism detected by PCR-SSP in a semi-urban HIV-positive Ugandan population.
PCR-SSP was used to HLA-type a cohort of Ugandan HIV-positive individuals. The results represent a more comprehensive description of HLA in an African population than previously described and are in concordance with data from a general Black population. Substantial differences exist between this population and Caucasoid populations in which immunological responses to HIV have been investigated; this emphasises that the main HLA-restrictive elements for HIV-specific cytotoxic T lymphocytes will most likely be different for each population
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