549 results on '"W. Lawson"'
Search Results
2. Misperception of peer beliefs reinforces inequitable gender norms among Tanzanian men
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David W. Lawson, Zhian Chen, Joseph A. Kilgallen, Charlotte O. Brand, Alexander M. Ishungisa, Susan B. Schaffnit, Yusufu Kumogola, and Mark Urassa
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Cultural evolution ,social learning ,social norms ,global health ,gender ,Human evolution ,GN281-289 ,Evolution ,QH359-425 - Abstract
Gender role ideology, i.e. beliefs about how genders should behave, is shaped by social learning. Accordingly, if perceptions about the beliefs of others are inaccurate this may impact trajectories of cultural change. Consistent with this premise, recent studies report evidence of a tendency to overestimate peer support for inequitable gender norms, especially among men, and that correcting apparent ‘norm misperception’ promotes transitions to relatively egalitarian beliefs. However, supporting evidence largely relies on self-report measures vulnerable to social desirability bias. Consequently, observed patterns may reflect researcher measurement error rather than participant misperception. Addressing this shortcoming, we examine men's gender role ideology using both conventional self-reported and a novel wife-reported measure of men's beliefs in an urbanising community in Tanzania. We confirm that participants overestimate peer support for gender inequity. However, the latter measure, which we argue more accurately captures men's true beliefs, implies that this tendency is relatively modest in magnitude and scope. Overestimation was most pronounced among men holding relatively inequitable beliefs, consistent with misperception of peer beliefs reinforcing inequitable norms. Furthermore, older and poorly educated men overestimated peer support for gender inequity the most, suggesting that outdated and limited social information contribute to norm misperception in this context.
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- 2024
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3. Design of a high-power, high-gain, 2nd harmonic, 22.848 GHz gyroklystron
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M. Veale, P. Purohit, and W. Lawson
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Physics ,QC1-999 - Abstract
In this paper we consider the design of a four-cavity, high-gain K-band gyroklystron experiment for high gradient structure testing. The frequency doubling gyroklystron utilizes a beam voltage of 500 kV and a beam current of 200 A from a magnetron injection gun (MIG) originally designed for a lower-frequency device. The microwave circuit features input and gain cavities in the circular TE011 mode and penultimate and output cavities that operate at the second harmonic in the TE021 mode. We investigate the MIG performance and study the behavior of the circuit for different values of perpendicular to parallel velocity ratio (α = V⊥ / Vz). This microwave tube is expected to be able to produce at least 20 MW of power in 1μs pulses at a repetition rate of at least 120 Hz. A maximum efficiency of 26% and a large signal gain of 58 dB under zero-drive stable conditions were simulated for a velocity ratio equal to 1.35.
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- 2013
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4. Gendered conflict in the human family
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David W. Lawson, Sarah Alami, and Oluwaseyi Dolapo Somefun
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sexual conflict ,cultural evolution ,social learning ,marriage ,reproduction ,Human evolution ,GN281-289 ,Evolution ,QH359-425 - Abstract
Sexual conflict is a thriving area of animal behaviour research. Yet parallel research in the evolutionary human sciences remains underdeveloped and has become mired by controversy. In this special collection, we aim to invigorate the study of fitness-relevant conflicts between women and men, advocating for three synergistic research priorities. First, we argue that a commitment to diversity is required to innovate the field, achieve ethical research practice, and foster fruitful dialogue with neighbouring social sciences. Accordingly, we have prioritised issues of diversity as editors, aiming to stimulate new connections and perspectives. Second, we call for greater recognition that human sex/gender roles and accompanying conflict behaviours are both subject to natural selection and culturally determined. This motivates our shift in terminology from sexual to gendered conflict when addressing human behaviour, countering stubborn tendencies to essentialise differences between women and men and directing attention to the role of cultural practices, normative sanctions and social learning in structuring conflict battlegrounds. Finally, we draw attention to contemporary policy concerns, including the wellbeing consequences of marriage practices and the gendered implications of market integration. Focus on these themes, combined with attendance to the dangers of ethnocentrism, promises to inform culturally sensitive interventions promoting gender equality worldwide.
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- 2023
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5. The distribution of North Atlantic right whales in Canadian waters from 2015-2017 revealed by passive acoustic monitoring
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Delphine Durette-Morin, Clair Evers, Hansen D. Johnson, Katie Kowarski, Julien Delarue, Hilary Moors-Murphy, Emily Maxner, Jack W. Lawson, and Kimberley T. A. Davies
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North Atlantic right whale (Eubalaena glacialis) ,passive acoustic monitoring (PAM) ,distribution ,range expansion ,regime shift ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
Northward range shifts are increasingly being identified in mobile animals that are responding to climate change. Range shifts are consequential to animal ecology, ecosystem function, and conservation goals, yet for many species these cannot be characterised without means of synoptically measuring their distribution. The distribution of critically endangered North Atlantic right whale (Eubalaena glacialis; NARW) north of 45°N has been largely unknown due to a lack of systematic monitoring. The objectives of this study were to characterize the spatial and temporal variation in NARW acoustic occurrence in the northern portion of their foraging range. In addition, we sought to identify relevant NARW migratory corridors and explore potential previously unidentified high-use habitats beyond the highly surveyed Gulf of St. Lawrence (GSL). To achieve this, passive acoustic monitoring data were collected and analyzed from 67 moorings and 13 gliders deployed (across 38 recording stations) throughout the Atlantic Canadian continental shelf, between 42°N and 58°N during 2015 through 2017. The results support that while a portion of the population has moved northward into the GSL, this shift was constrained to temperate latitudinal ranges < 52°N during the study period. NARWs were not detected in the Labrador Sea and Newfoundland Shelf, despite their preferred prey occurring in those areas. NARWs were present on the Scotian Shelf (45°N) nearly year-round, but only from May through December in the Cabot Strait (50°N). These results indicate that the northern range of the population is probably influenced by energetic requirements to minimize the distance between suitable foraging habitat and low latitude calving grounds, rather than an absence of suitable foraging conditions in high latitude waters, or other environmental or physiological factors. This work provides critical information to conserve the species and mitigate human-induced risks.
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- 2022
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6. A 3D Printable Alloy Designed for Extreme Environments
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Timothy M. Smith, Christopher A. Kantzos, Nikolai A. Zarkevich, Bryan J. Harder, Milan Heczko, Paul R. Gradl, Aaron C. Thompson, Michael J. Mills, Timothy P. Gabb, and John W. Lawson
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Chemistry and Materials (General) ,Structural Mechanics ,Composite Materials - Abstract
Multiprincipal-element alloys are an enabling class of materials owing to their impressive mechanical and oxidation-resistant properties, especially in extreme environments. Here we develop a new oxide-dispersion-strengthened NiCoCr-based alloy using a model-driven alloy design approach and laser-based additive manufacturing. This oxide-dispersion-strengthened alloy, called GRX-810, uses laser powder bed fusion to disperse nanoscale Y2O3 particles throughout the microstructure without the use of resource-intensive processing steps such as mechanical or in situ alloying. We show the successful incorporation and dispersion of nanoscale oxides throughout the GRX-810 build volume via high-resolution characterization of its microstructure. The mechanical results of GRX-810 show a twofold improvement in strength, over 1,000-fold better creep performance and twofold improvement in oxidation resistance compared with the traditional polycrystalline wrought Ni-based alloys used extensively in additive manufacturing at 1,093 °C. The success of this alloy highlights how model-driven alloy designs can provide superior compositions using far fewer resources compared with the ‘trial-and-error’ methods of the past. These results showcase how future alloy development that leverages dispersion strengthening combined with additive manufacturing processing can accelerate the discovery of revolutionary materials.
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- 2023
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7. Utilizing local phase transformation strengthening for nickel-base superalloys
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Timothy M. Smith, Nikolai A. Zarkevich, Ashton J. Egan, Joshua Stuckner, Timothy P. Gabb, John W. Lawson, and Michael J. Mills
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Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
There is an ongoing need to increase the operating temperature of jet engines, requiring new high-temperature materials. Here, local phase transformations at superlattice stacking faults contribute to a three times improvement in creep strength in a Ni-based superalloy.
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- 2021
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8. Energy-Composition Relations in Ni3(Al1−xXx) Phases
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Nikolai A. Zarkevich, Timothy M. Smith, and John W. Lawson
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energy ,composition ,precipitation ,strengthening ,superalloys ,theory ,Crystallography ,QD901-999 - Abstract
The secondary phase, such as Ni3Al-based L12 γ′, is crucially important for the precipitation strengthening of superalloys. Composition–structure–property relations provide useful insights for guided alloy design. Here we use density functional theory combined with the multiple scattering theory to compute dependencies of the structural energies and equilibrium volumes versus composition for ternary Ni3(Al1−xXx) alloys with X = {Ti, Zr, Hf; V, Nb, Ta; Cr, Mo, W} in L12, D024, and D019 phases with a homogeneous chemical disorder on the (Al1−xXx) sublattice. Our results provide a better understanding of the physics in Ni3Al-based precipitates and facilitate the design of next-generation nickel superalloys with precipitation strengthening.
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- 2023
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9. Why marry early? Parental influence, agency and gendered conflict in Tanzanian marriages
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Jitihada Baraka, David W Lawson, Susan B Schaffnit, Joyce Wamoyi, and Mark Urassa
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Sexual conflict ,parent–offspring conflict ,child marriage ,bridewealth ,human behavioural ecology ,Human evolution ,GN281-289 ,Evolution ,QH359-425 - Abstract
Global health interventions increasingly target the abolishment of ‘child marriage’ (marriage under 18 years, hereafter referred to as ‘early marriage’). Guided by human behavioural ecology theory, and drawing on focus groups and in-depth interviews in an urbanising Tanzanian community where female early marriage is normative, we examine the common assumption that it is driven by the interests and coercive actions of parents and/or men. We find limited support for parent–offspring conflict. Parents often encouraged early marriages, but were motivated by the promise of social and economic security for daughters, rather than bridewealth transfers alone. Moreover, forced marriage appears rare, and adolescent girls and young women (AGYW) were active agents in the transition to marriage, sometimes marrying against parental wishes. Support for gendered conflict was stronger. AGYW were described as being lured into unstable relationships by men misrepresenting their long-term intentions. Community members voiced concerns over these marriages. Overall, early marriage appears rooted in limited options, encouraging strategic, but risky choices on the marriage market. Our results highlight plurality and context dependency in drivers of early marriage, even within a single community. We conclude that engaging with the importance of context is fundamental in forging culturally sensitive policies and programs on early marriage.
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- 2022
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10. Regeneration and growth in crowns and rhizome fragments of Japanese knotweed (Reynoutria japonica) and desiccation as a potential control strategy
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Jacob W. Lawson, Mark Fennell, Mark W. Smith, and Karen L. Bacon
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Japanese knotweed ,Regeneration ,Nodes ,Crowns ,Rhizomes ,Desiccation ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Reynoutria japonica (Japanese knotweed) is a problematic invasive plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition. Control of R. japonica is complicated by its ability to regenerate from small fragments of plant material; however, there remains uncertainty about how much (in terms of mass) rhizome is required for successful regeneration. This study investigated the ability of crowns and rhizomes with different numbers of nodes to regenerate successfully from three sites in the north of England, UK. Two of the sites had been subject to herbicide treatment for two years prior to sampling and the third site had no history of herbicide treatment. No significant differences were observed in regenerated stem diameter, maximum height of stem and maximum growth increments among crowns. All traits measured from the planted crowns were significantly greater than those of the planted rhizome fragments and at least one node was necessary for successful regeneration of rhizomes. The smallest initial fragment weight to regenerate and survive the experiment was 0.5 g. Subjecting all plant material to desiccation for 38 days resulted in no regrowth (emergence or regeneration) after replanting. These findings suggest that desiccation could be a valuable management strategy for small to medium scale infestations common in urban settings.
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- 2021
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11. The leucine-rich repeats in allelic barley MLA immune receptors define specificity towards sequence-unrelated powdery mildew avirulence effectors with a predicted common RNase-like fold.
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Saskia Bauer, Dongli Yu, Aaron W Lawson, Isabel M L Saur, Lamprinos Frantzeskakis, Barbara Kracher, Elke Logemann, Jijie Chai, Takaki Maekawa, and Paul Schulze-Lefert
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Nucleotide-binding domain leucine-rich repeat-containing receptors (NLRs) in plants can detect avirulence (AVR) effectors of pathogenic microbes. The Mildew locus a (Mla) NLR gene has been shown to confer resistance against diverse fungal pathogens in cereal crops. In barley, Mla has undergone allelic diversification in the host population and confers isolate-specific immunity against the powdery mildew-causing fungal pathogen Blumeria graminis forma specialis hordei (Bgh). We previously isolated the Bgh effectors AVRA1, AVRA7, AVRA9, AVRA13, and allelic AVRA10/AVRA22, which are recognized by matching MLA1, MLA7, MLA9, MLA13, MLA10 and MLA22, respectively. Here, we extend our knowledge of the Bgh effector repertoire by isolating the AVRA6 effector, which belongs to the family of catalytically inactive RNase-Like Proteins expressed in Haustoria (RALPHs). Using structural prediction, we also identified RNase-like folds in AVRA1, AVRA7, AVRA10/AVRA22, and AVRA13, suggesting that allelic MLA recognition specificities could detect structurally related avirulence effectors. To better understand the mechanism underlying the recognition of effectors by MLAs, we deployed chimeric MLA1 and MLA6, as well as chimeric MLA10 and MLA22 receptors in plant co-expression assays, which showed that the recognition specificity for AVRA1 and AVRA6 as well as allelic AVRA10 and AVRA22 is largely determined by the receptors' C-terminal leucine-rich repeats (LRRs). The design of avirulence effector hybrids allowed us to identify four specific AVRA10 and five specific AVRA22 aa residues that are necessary to confer MLA10- and MLA22-specific recognition, respectively. This suggests that the MLA LRR mediates isolate-specific recognition of structurally related AVRA effectors. Thus, functional diversification of multi-allelic MLA receptors may be driven by a common structural effector scaffold, which could be facilitated by proliferation of the RALPH effector family in the pathogen genome.
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- 2021
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12. He for she? Variation and exaggeration in men's support for women's empowerment in northern Tanzania
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David W. Lawson, Susan B. Schaffnit, Joseph A. Kilgallen, Yusufu Kumogola, Anthony Galura, and Mark Urassa
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Gender equality ,patriarchy ,sexual conflict ,social norms ,global health ,marriage ,Human evolution ,GN281-289 ,Evolution ,QH359-425 - Abstract
Achieving gender equality fundamentally requires a transfer of power from men to women. Yet data on men's support for women's empowerment (WE) remains scant and limited by reliance on self-report methodologies. Here, we examine men's support for WE as a sexual conflict trait, both via direct surveys (n = 590) and indirectly by asking men's wives (n = 317) to speculate on their husband's views. Data come from a semi-urban community in Mwanza, Tanzania. Consistent with reduced resource competition and increased exposure to relatively egalitarian gender norms, higher socioeconomic status predicted greater support for WE. However, potential demographic indicators of sexual conflict (high fertility, polygyny, large spousal age gap) were largely unrelated to men's support for WE. Contrasting self- and wife-reported measures suggests that men frequently exaggerate their support for women in self-reported attitudes. Discrepancies were especially pronounced among men claiming the highest support for WE, but smallest among men who held a professional occupation and whose wife participated in wage labour, indicating that these factors predict genuine support for WE. We discuss the implications of these results for our understanding of both individual variation and patriarchal gender norms, emphasising the benefits of greater exchange between the evolutionary human sciences and global health research on these themes.
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- 2021
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13. Amino acid δ15N differences consistent with killer whale ecotypes in the Arctic and Northwest Atlantic.
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Cory J D Matthews, Jack W Lawson, and Steven H Ferguson
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Medicine ,Science - Abstract
Ecotypes are groups within a species with different ecological adaptations than their conspecifics. Eastern North Pacific (ENP) killer whale (Orcinus orca) ecotypes differ in their diet, behavior, and morphology, but the same is not known for this species in the eastern Canadian Arctic (ECA) and Northwest Atlantic (NWA). Using compound-specific stable isotope analysis (CSIA) of amino acids (AAs), we compared δ15N patterns of the primary trophic and source AA pair, glutamic acid/glutamine (Glx) and phenylalanine (Phe), in dentine collagen of (1) sympatric ENP killer whale ecotypes with well-characterized diet differences and (2) ECA/NWA killer whales with unknown diets. δ15NGlx-Phe was significantly higher in the ENP fish-eating (FE) than mammal-eating (ME) ecotype (19.2 ± 0.4‰ vs. 13.5 ± 0.7‰, respectively). Similar bimodal variation in δ15NGlx-Phe indicated analogous dietary divisions among ECA/NWA killer whales, with two killer whales having higher δ15NGlx-Phe (16.5 ± 0.0‰) than the others (13.5 ± 0.6‰). Inferences of dietary divisions between these killer whales were supported by parallel differences in threonine δ15N (-33.5 ± 1.6‰ and -40.4 ± 1.1‰, respectively), given the negative correlation between δ15NThr and TP across a range of marine consumers. CSIA-AA results for ECA/NWA whales, coupled with differences in tooth wear (a correlate for diet), are consistent with ecotype characteristics reported in ENP and other killer whale populations, thus adding to documented ecological divergence in this species worldwide.
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- 2021
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14. 'I have never seen something like that': Discrepancies between lived experiences and the global health concept of child marriage in northern Tanzania.
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Susan B Schaffnit, Mark Urassa, Joyce Wamoyi, Maria Dardoumpa, and David W Lawson
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Medicine ,Science - Abstract
BackgroundThe concept of 'child marriage' in global health distinguishes ostensibly harmful from healthy ages to marry at a universally-applied threshold of 18-years. With intensifying efforts to end child marriage, targeted communities are increasingly asked to change their perception of such marriages from relatively benign to profoundly problematic. The objective of this study is to understand how this shift in perception is navigated by adolescent girls and young women (AGYW).MethodsUsing qualitative data collected in 2019 from a semi-urban community in Tanzania where marriage under 18-years is common and campaigns to end child marriage ongoing, we contrast reports of lived experiences of marriage under 18-years among AGYW to views of child marriage as an abstract concept. Thirteen in-depth interviews with AGYW, as part of a wider qualitative study, were recorded, transcribed, and analyzed using a framework analysis approach.ResultsWhile many AGYW had heard of child marriage, the concept was routinely conflated with forced marriage, which is rare in the community, and non-marital teenage sex and pregnancy, which are common. As a likely consequence, participants disagreed on whether or not child marriage occurs locally. Furthermore, accounts of real-life marriages under 18 sometimes aligned with, but often departed from, common narratives about the purported causes and harmful consequences inherent to the global health concept of child marriage.ConclusionsWe argue that engaging with diverse local views and experiences of marrying young is essential to producing culturally-sensitive, effective initiatives addressing the vulnerabilities of female adolescence.
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- 2021
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15. Distribution and Abundance of the Eastern Canada – West Greenland Bowhead Whale Population Based on the 2013 High Arctic Cetacean Survey
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Thomas Doniol-Valcroze, Jean-François Gosselin, Daniel G. Pike, Jack W. Lawson, Natalie C. Asselin, Kevin J. Hedges, and Steven H. Ferguson
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bowhead whale ,Baffin Bay ,Eastern-Canada West-Greenland ,abundance ,aerial survey ,double-platform ,Ecology ,QH540-549.5 - Abstract
The hunting of bowhead whales (Balaena mysticetus) is an integral part of Inuit culture. An up-to-date abundance estimate of the entire Eastern Canada – West Greenland (EC-WG) bowhead population is necessary to support sustainable management of this harvest. The High Arctic Cetacean Survey (HACS) was conducted in August 2013, primarily to update abundance estimates for known stocks of Baffin Bay narwhal (Monodon monoceros). As the ranges of narwhal and bowhead largely overlap, the survey area was expanded to cover the summer range of bowhead whales. Bowhead whale abundance was estimated using 3 aircraft to cover the large survey area within a short time frame. Distance sampling methods were used to estimate detection probability away from the track line. Double platform with mark-recapture methods were used to correct for the proportion of whales missed by visual observers on the track line (perception bias). Abundance in Isabella Bay, an area known for high bowhead density, was estimated using density surface modelling to account for its complex shape and uneven coverage. Estimates were corrected for availability bias (whales that were not available for detection because they were submerged when the aircraft passed overhead) using a recent analysis of satellite-linked time depth recorders transmitting information on the diving behaviour of bowhead whales in the study area in August of the same survey year. The fully corrected abundance estimate for the EC-WG bowhead whale population was 6,446 (95% CI: 3,838–10,827). Possible sources of uncertainty include incomplete coverage and the diving behaviour of bowhead whales. These results confirm earlier indications that the EC-WG stock is continuing to recover from past overexploitation.
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- 2020
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16. Narwhal Abundance in the Eastern Canadian High Arctic in 2013
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Thomas Doniol-Valcroze, Jean-François Gosselin, Daniel G. Pike, Jack W. Lawson, Natalie C. Asselin, Kevin Hedges, and Steven H. Ferguson
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narwhal ,Baffin Bay ,summer stocks ,abundance ,aerial survey ,double-platform ,Ecology ,QH540-549.5 - Abstract
In summer, narwhals (Monodon monoceros) migrate from Baffin Bay to northeastern Canada and northwest Greenland, where they are hunted by Inuit for subsistence. To prevent localized depletion, management of narwhals is based on summer stocks. The High Arctic Cetacean Survey (HACS), conducted in August 2013, was the first survey to estimate abundance of all 4 Canadian Baffin Bay narwhal summer stocks, as well as putative stocks in Jones Sound and Smith Sound, in the same summer. Narwhal abundance was estimated using a double-platform aerial survey. Distance sampling methods were used to estimate detection probability away from the track line. Mark-recapture methods were used to correct for the proportion of narwhals missed by visual observers on the track line (i.e., perception bias). We used a data-driven approach to identify single and duplicate sightings, using 4 covariates to compare differences in sightings made by front and rear observers based on: time of sighting, declination angle, group size, and species identity. Abundance in fjords was estimated using density surface modelling to account for their complex shape and uneven coverage. Estimates were corrected for availability bias (narwhals that are not available for detection because they are submerged when the aircraft passes overhead) using a new analysis of August dive behaviour data from narwhals equipped with satellite-linked time depth recorders. Corrected abundance estimates were 12,694 (95% CI: 6,324–25,481) for the Jones Sound stock; 16,360 (95% CI: 3,833–69,836) for the Smith Sound stock; 49,768 (95% CI: 32,945–75,182) for the Somerset Island stock; 35,043 (95% CI: 14,188–86,553) for the Admiralty Inlet stock; 10,489 (95% CI: 6,342–17,347) for the Eclipse Sound stock; and 17,555 (95% CI: 8,473–36,373) for the East Baffin Island stock. Total abundance for these 6 stocks was estimated at 141,908 (95% CI: 102,464–196,536). Sources of uncertainty arise from the high level of clustering observed, in particular in Admiralty Inlet, Eclipse Sound, and East Baffin Island, as well as the difficulty in identifying duplicate sightings between observers when large aggregations were encountered.
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- 2020
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17. Mixed-Domain Charge Transport in the S–Se System from First-Principles
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Junsoo Park, Zhigang Wu, and John W. Lawson
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General Chemical Engineering ,Biomedical Engineering ,General Materials Science - Published
- 2022
18. What does the American public know about child marriage?
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David W Lawson, Rachel Lynes, Addison Morris, and Susan B Schaffnit
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Medicine ,Science - Abstract
Global efforts to eradicate 'child marriage' (
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- 2020
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19. Modeling Singlet Oxygen-Induced Degradation Pathways Including Environmental Effects of 1,2-Dimethoxyethane in Li–O2 Batteries through Density Functional Theory
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J. Wayne Mullinax, Charles W. Bauschlicher, and John W. Lawson
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Physical and Theoretical Chemistry - Published
- 2022
20. Microscopic deformation and failure modes of high‐functionality epoxy resins from bond breaking molecular dynamics simulations and experimental investigation
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Chang Woon Jang, J. Wayne Mullinax, Jin Ho Kang, Frank L. Palmieri, Tyler B. Hudson, and John W. Lawson
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Polymers and Plastics ,Materials Chemistry ,General Chemistry - Published
- 2022
21. A systematic review and meta-analysis of the diagnostic effectiveness of human papillomavirus methylation biomarkers for detection of cervical cancer
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Christopher RT Hillyar, Shivani S Kanabar, Kamil R Pufal, Alexander W Lawson, Joshua Li Saw Hee, Kathrine S Rallis, Anjan Nibber, and Michail Sideris
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Cancer Research ,Papillomavirus Infections ,Genetics ,Humans ,Uterine Cervical Neoplasms ,Female ,Alphapapillomavirus ,Uterine Cervical Dysplasia ,Methylation ,Papillomaviridae ,Precancerous Conditions ,Biomarkers ,Early Detection of Cancer - Abstract
This study reviewed the literature to assess the available evidence for the ability of biomarkers based on human papillomavirus (HPV) methylation (i.e., the detection of methyl groups in HPV DNA in cervical specimens) to screen for cervical precancerous and cancerous lesions. Scientific databases were searched, and abstracts screened for relevance. The quality of the included articles was assessed using a quality assessment tool called QUADAS-2. The main diagnostic performance parameter extracted from the included articles was the receiver operating characteristic (ROC), a measure of the ability of a biomarker to detect all true cases (true positives) while excluding all true non-cases (true negatives). After screening, nine articles were included, of which seven were of moderate quality and two were of high quality. ROC data were extracted for 27 biomarkers, of which four methylation biomarkers had high diagnostic ability (i.e., ROC 0.900), 17 had moderate diagnostic ability (ROC: 0.7000–0.8999) and six had low diagnostic ability (ROC 0.700). An umbrella meta-analysis (i.e., a weighted-average ROC for all HPV methylation biomarkers) revealed an ROC consistent with moderate diagnostic ability (0.770). The main conclusion from this study was that HPV methylation biomarkers, especially ones with high diagnostic ability, hold significant promise as independent screening tests for the detection of cervical precancerous and cancerous lesions.
- Published
- 2022
22. Complete Genome Sequences of Chop, DelRio, and GrandSlam, Three Gordonia Phages Isolated from Soil in Central Arkansas
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Heidi N. Mathes, Elijah I. Christenson, John H. Crum, Emme M. Edmondson, Kassidy E. Gray, Luke W. Lawson, Lauren E. Lee, Michael P. Lee, Jackson A. Lipscomb, Morgan E. Masengale, Hannah G. Matthews, Charles M. McClain, Tuesday N. Melton, Trace H. Morrow, Alexis M. Perry, David R. Rainwater, Grace E. Renois, Maryann F. Rettig, Duncan C. Troup, Allie J. Wilson, Nathan S. Reyna, and Ruth Plymale
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Immunology and Microbiology (miscellaneous) ,Genetics ,Molecular Biology - Abstract
Chop, DelRio, and GrandSlam are phage with a Siphoviridae morphotype isolated from soil in Arkansas using the host Gordonia terrae 3612. All three are temperate, and their genomes share at least 96% nucleotide identity. These phage are assigned to cluster DI based on gene content similarity to other sequenced actinobacteriophage.
- Published
- 2023
23. Structural polymorphisms within a common powdery mildew effector scaffold as a driver of co-evolution with cereal immune receptors
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Yu Cao, Florian Kümmel, Elke Logemann, Jan M. Gebauer, Aaron W. Lawson, Dongli Yu, Matthias Uthoff, Beat Keller, Jan Jirschitzka, Ulrich Baumann, Kenichi Tsuda, Jijie Chai, and Paul Schulze-Lefert
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ddc:570 - Abstract
In plants, host–pathogen coevolution often manifests in reciprocal, adaptive genetic changes through variations in host nucleotide-binding leucine-rich repeat immune receptors (NLR) and virulence-promoting pathogen effectors. In grass powdery mildew (PM) fungi, an extreme expansion of a RNase-like effector family, termed RALPH, dominates the effector repertoire, with some members recognized as avirulence (AVR) effectors by cereal NLR receptors. We report the structures of the sequence-unrelated barley PM effectors AVRA6, AVRA7and allelic AVRA10/AVRA22variants, which are detected by highly sequence-related barley NLRs MLA6, MLA7, MLA10, and MLA22, and of wheat PM AVRPM2detected by the unrelated wheat NLR PM2. The AVR effectors adopt a common scaffold, which is shared with the ribonuclease (RNase) T1/F1-family. We found striking variations in the number, position, and length of individual structural elements between RALPH AVRs, which is associated with a differentiation of RALPH effector subfamilies. We show that all RALPH AVRs tested have lost nuclease and synthetase activities of the RNase T1/F1- family and lack significant binding to RNA, implying that their virulence activities are associated with neo-functionalization events. Structure-guided mutagenesis identified six AVRA6residues that are sufficient to turn a sequence-diverged member of the same RALPH subfamily into an effector specifically detected by MLA6. Similar structure-guided information for AVRA10and AVRA22indicates that MLA receptors detect largely distinct effector surface patches. Thus, coupling of sequence and structural polymorphisms within the RALPH scaffold of PMs facilitated escape from NLR recognition and potential acquisition of diverse virulence functions.
- Published
- 2023
24. Married Too Young? The Behavioral Ecology of ‘Child Marriage’
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Susan B. Schaffnit and David W. Lawson
- Subjects
child marriage ,anthropology ,human behavioral ecology ,global health ,harmful cultural practices ,life history theory ,Social Sciences - Abstract
For girls and women, marriage under 18 years is commonplace in many low-income nations today and was culturally widespread historically. Global health campaigns refer to marriage below this threshold as ‘child marriage’ and increasingly aim for its universal eradication, citing its apparent negative wellbeing consequences. Here, we outline and evaluate four alternative hypotheses for the persistence of early marriage, despite its associations with poor wellbeing, arising from the theoretical framework of human behavioral ecology. First, early marriage may be adaptive (e.g., it maximizes reproductive success), even if detrimental to wellbeing, when life expectancy is short. Second, parent–offspring conflict may explain early marriage, with parents profiting economically at the expense of their daughter’s best interests. Third, early marriage may be explained by intergenerational conflict, whereby girls marry young to emancipate themselves from continued labor within natal households. Finally, both daughters and parents from relatively disadvantaged backgrounds favor early marriage as a ‘best of a bad job strategy’ when it represents the best option given a lack of feasible alternatives. The explanatory power of each hypothesis is context-dependent, highlighting the complex drivers of life history transitions and reinforcing the need for context-specific policies addressing the vulnerabilities of adolescence worldwide.
- Published
- 2021
- Full Text
- View/download PDF
25. DC Modeling of 4H-SiC nJFET Gate Length Reduction at 500°C
- Author
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Mohit R. Mehta, Philip G. Neudeck, and John W. Lawson
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Abstract
The development of robust, high-performance integrated circuits (ICs) will enable numerous potential NASA missions of current interest, including long-duration robotic missions exploring the 460°C surface of Venus. Currently, NASA is looking towards SiC-based devices to provide such a solution. However, the current NASA silicon carbide (SiC) JFET device with a channel length of 6 μm (recently fabricated Gen. 11 ICs) limits mission-relevant circuit capabilities. In this study, we combined experiments with simulations to explore two straightforward fabrication strategies (shallow n−and extended n+) to reduce the SiC JFET channel length while maintaining the turn-off behavior needed to realize 500°C circuit operation. COMSOL Multiphysics was used to simulate the transfer characteristics and maximum potential below the gate of a 4H-SiC nJFET at 500°C, and a 1 μm gate length nJFET with turn-off performance comparable to the state-of-the-art is suggested.
- Published
- 2022
26. Fathers favour sons, mothers don't discriminate: Sex-biased parental care in northwestern Tanzania
- Author
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Anushé Hassan, Susan B. Schaffnit, Rebecca Sear, Mark Urassa, and David W. Lawson
- Subjects
parental investment ,sex-biased care ,paternal son-bias ,early childhood ,Tanzania ,Human evolution ,GN281-289 ,Evolution ,QH359-425 - Abstract
Variation in parental care by child's sex is evident across cultures. Evolutionary theory provides a functional explanation for this phenomenon, predicting that parents will favour specific children if this results in greater fitness payoffs. Here, we explore evidence for sex-biased parental care in a high-fertility, patriarchal and polygynous population in Tanzania, predicting that both mothers and fathers will favour sons in this cultural setting. Our data come from a cross-sectional study in rural northwestern Tanzania, which included surveys with mothers/guardians of 808 children under age 5. We focus on early childhood, a period with high mortality risk which is fundamental in establishing later-life physical and cognitive development. Examining multiple measures of direct/physical care provision (washing, feeding, playing with, supervising, co-sleeping and caring when sick), we demonstrate that fathers favour sons for washing, feeding and supervising, while maternal care is both more intensive and unrelated to child sex. We find no difference in parental care between girls and boys regarding the allocation of material resources and the duration of breastfeeding; or in terms of parental marital and co-residence status. This bias towards sons may result from higher returns to investment for fathers than mothers, and local gender norms about physical care provision.
- Published
- 2019
- Full Text
- View/download PDF
27. Supplementary Figure 1 from Glutathione-Deficient Mice Have Increased Sensitivity to Transplacental Benzo[a]pyrene-Induced Premature Ovarian Failure and Ovarian Tumorigenesis
- Author
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Ulrike Luderer, Terrance J. Kavanagh, Jin A. Hur, Laura Ortiz, Brooke N. Nakamura, Gregory W. Lawson, and Jinhwan Lim
- Abstract
PDF file - 9.7MB, Hematoxylin and eosin stained sections of ovarian tumors in Gclm+/+ and Gclm-/- F1 females prenatally exposed to BaP
- Published
- 2023
28. Coarse-Grained Dynamically Accurate Simulations of Ionic Liquids: [pyr14][TFSI] and [EMIM][BF4]
- Author
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Tyler D. Stoffel, Justin B. Haskins, John W. Lawson, and Sergiy Markutsya
- Subjects
Materials Chemistry ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films - Published
- 2022
29. Effect of Husbandry Practices on the Fecal Microbiota of C57BL/6J Breeding Colonies Housed in 2 Different Barrier Facilities in the Same Institution
- Author
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Libette J Roman, Antoine M Snijders, Hang Chang, Jian-Hua Mao, Kristina JA Jones, and Gregory W Lawson
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Male ,Agricultural and Veterinary Sciences ,Microbiota ,Reproducibility of Results ,Biological Sciences ,Inbred C57BL ,Medical and Health Sciences ,Gastrointestinal Microbiome ,Feces ,Mice ,Animals ,Animal Science and Zoology ,Female ,Veterinary Sciences ,Original Research - Abstract
Evidence showing a relationship between the mouse gut microbiome and properties such as phenotype and reaction to therapeutic agents and other treatments has increased significantly over the past 20 to 30 y. Recent concerns regarding the reproducibility of animal experiments have underscored the importance of understanding this relationship and how differences in husbandry practices can affect the gut microbiome. The current study focuses on effects of different barrier practices in 2 barrier facilities at the same institution on the fecal microbiome of breeding C57Bl/6J mice. Ten female and 10 male C57Bl/6J mice were obtained in one shipment from Jackson Laboratories and were housed under different barrier conditions upon arrival. Fecal samples were collected on arrival and periodically thereafter and were sent to TransnetYX for microbiome analysis. Mice used for collection of feces were housed as breeding pairs, with a total of 5 breeding pairs per barrier. An additional fecal sample was collected from these mice at 8 wk after arrival. One F1 female and one F1 male from each breeding cage were housed as brother-sister breeding pairs and a fecal sample was collected from them at 8 wk of age. Brother-sister breeding colonies were continued through F3, with fecal samples for microbiome analysis were collected from each generation at 8 wk of age. Breeding colonies in the 2 barriers showed differences in relative abundance, α -diversity, and β -diversity. Our data indicate that differences in barrier husbandry practices, including the use of autoclaved cages, the degree of restricted access, feed treatment practices, and water provision practices, can affect fecal microbiome divergence in both the parental and filial generations of different breeding colonies. To our knowledge, this is the first study to examine the effect of barrier husbandry practices on the microbiome of breeding colonies through the F3 generation.
- Published
- 2023
30. Stable and Efficient Lithium Metal Anode Cycling through Understanding the Effects of Electrolyte Composition and Electrode Preconditioning
- Author
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Dmitrii Rakov, Meisam Hasanpoor, Artem Baskin, John W. Lawson, Fangfang Chen, Pavel V. Cherepanov, Alexandr N. Simonov, Patrick C. Howlett, and Maria Forsyth
- Subjects
General Chemical Engineering ,Materials Chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,0104 chemical sciences - Published
- 2021
31. Redefining North Atlantic right whale habitat‐use patterns under climate change
- Author
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Erin L. Meyer‐Gutbrod, Kimberley T. A. Davies, Catherine L. Johnson, Stephane Plourde, Kevin A. Sorochan, Robert D. Kenney, Christian Ramp, Jean‐Francois Gosselin, Jack W. Lawson, and Charles H. Greene
- Subjects
Aquatic Science ,Oceanography - Published
- 2022
32. Molecular dynamics simulation of twin nucleation and growth in Ni-based superalloys
- Author
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Valery V. Borovikov, Mikhail I. Mendelev, Timothy M. Smith, and John W. Lawson
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2023
33. Ancient variation of the
- Author
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Marion C, Müller, Lukas, Kunz, Seraina, Schudel, Aaron W, Lawson, Sandrine, Kammerecker, Jonatan, Isaksson, Michele, Wyler, Johannes, Graf, Alexandros G, Sotiropoulos, Coraline R, Praz, Beatrice, Manser, Thomas, Wicker, Salim, Bourras, and Beat, Keller
- Subjects
Plant Breeding ,Secale ,Quantitative Trait Loci ,Chromosome Mapping ,Genetic Introgression ,Triticum ,Disease Resistance ,Plant Diseases - Abstract
Introgressions of chromosomal segments from related species into wheat are important sources of resistance against fungal diseases. The durability and effectiveness of introgressed resistance genes upon agricultural deployment is highly variable-a phenomenon that remains poorly understood, as the corresponding fungal avirulence genes are largely unknown. Until its breakdown, the
- Published
- 2022
34. Reaction of Singlet Oxygen with the Ethylene Group: Implications for Electrolyte Stability in Li-Ion and Li-O2 Batteries
- Author
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Charles W. Bauschlicher, J. Wayne Mullinax, and John W. Lawson
- Subjects
Ethylene ,010304 chemical physics ,Singlet oxygen ,Multireference configuration interaction ,Electrolyte ,010402 general chemistry ,01 natural sciences ,Quantum chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Computational chemistry ,0103 physical sciences ,Density functional theory ,Complete active space ,Physical and Theoretical Chemistry ,Ethylene carbonate - Abstract
Recent experimental and computational evidence indicates that singlet oxygen (1O2) attacks the ethylene group (-CH2-CH2-) in ethylene carbonate (EC) leading to degradation in Li-ion batteries employing EC as the electrolyte solvent [J. Phys. Chem. A2018, 122, 8828-8839]. Here, we employ computational quantum chemistry to explore this mechanism in detail for a large set of organic molecules. Benchmark calculations comparing density functional theory to the complete active space second-order perturbation theory and internally contracted multireference configuration interaction indicate that the M11 functional adequately captures trends in the transition-state energies for this mechanism. Based on our results, we recommend that solvents which include the ethylene group should be avoided in Li-ion and Li-O2 batteries where 1O2 is generated unless neighboring functional groups raise the reaction barrier to avoid this decomposition pathway.
- Published
- 2021
35. Cross-cultural research must prioritize equitable collaboration
- Author
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Purnima Madhivanan, Eshetu Gurmu, Mhairi A. Gibson, Mark Urassa, David W. Lawson, Caitlyn D. Placek, and Joyce Wamoyi
- Subjects
0303 health sciences ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,Social Psychology ,Biological anthropology ,Social anthropology ,Experimental and Cognitive Psychology ,Engineering ethics ,Sociology ,Cross-cultural studies ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
Research centres in low- and middle-income countries are routinely circumvented in the production of cross-cultural research on human behaviour. Where local contributions are made, collaboration is rarely equitable and often uncredited in co-authorship. Efforts to decolonize the social sciences will remain inadequate until these norms are overturned.
- Published
- 2021
36. Shared interests or sexual conflict? Spousal age gap, women's wellbeing and fertility in rural Tanzania
- Author
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Susan B. Schaffnit, Mark Urassa, Anushé Hassan, and David W. Lawson
- Subjects
medicine.medical_specialty ,Inequality ,media_common.quotation_subject ,Public health ,05 social sciences ,050109 social psychology ,Experimental and Cognitive Psychology ,Context (language use) ,Fertility ,social sciences ,Mental health ,050105 experimental psychology ,Sexual conflict ,Arts and Humanities (miscellaneous) ,behavior and behavior mechanisms ,medicine ,0501 psychology and cognitive sciences ,Seniority ,Psychology ,Ecology, Evolution, Behavior and Systematics ,Autonomy ,Demography ,media_common - Abstract
The marriage of older men to younger women is common across cultures. On one hand, husband-older marriage may serve the interests of both sexes, a conclusion broadly consistent with reported gender differences in mate preferences. On the other hand, men alone may benefit from such marriages at a cost to women if seniority enables men to exert dominance in conflicts of interest. Indeed, in public health large spousal age gaps are generally deemed “pathological”, both as a cause and consequence of gender inequalities harmful to women. We investigate these alternative models of spousal age gap using data from a cross-sectional survey of women in Mwanza, northwestern Tanzania (n = 993). Consistent with the notion that spousal age gaps are a product of sexual conflict, women typically married with a larger age gap than stated ideals. However, adjusting for potential confounds, spousal age gap was not associated with fertility or the risk of divorce. Furthermore, women's mental health and autonomy in household decision-making was higher in husband-older marriages compared to rare cases of same-age or wife-older marriage. Beyond this comparison, the magnitude of spousal age gaps was unrelated to either measure of women's wellbeing among the overwhelming majority of marriages where the husband was older. Together these findings suggest husband-older marriage does not influence marital stability, relatively large spousal age gaps are neither especially costly nor beneficial to women, and that alternative sociodemographic factors are more important in driving variation in women's wellbeing and reproductive success in this context. Our results support neither a model of mutual benefits, nor a pathological conceptualization of spousal age gaps. We conclude by both encouraging evolutionary human scientists to engage more fully with models of sexual conflict in future studies of marriage and mating, and suggesting that public health scholars consider more neutral interpretations of spousal age differences.
- Published
- 2021
37. Ancient variation of the AvrPm17 gene in powdery mildew limits the effectiveness of the introgressed rye Pm17 resistance gene in wheat
- Author
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Marion C. Müller, Lukas Kunz, Seraina Schudel, Aaron W. Lawson, Sandrine Kammerecker, Jonatan Isaksson, Michele Wyler, Johannes Graf, Alexandros G. Sotiropoulos, Coraline R. Praz, Beatrice Manser, Thomas Wicker, Salim Bourras, Beat Keller, University of Zurich, Müller, Marion C, Bourras, Salim, and Keller, Beat
- Subjects
UFSP13-7 Evolution in Action: From Genomes to Ecosystems ,1000 Multidisciplinary ,Multidisciplinary ,10126 Department of Plant and Microbial Biology ,580 Plants (Botany) ,10211 Zurich-Basel Plant Science Center - Abstract
Introgressions of chromosomal segments from related species into wheat are important sources of resistance against fungal diseases. The durability and effectiveness of introgressed resistance genes upon agricultural deployment is highly variable—a phenomenon that remains poorly understood, as the corresponding fungal avirulence genes are largely unknown. Until its breakdown, the Pm17 resistance gene introgressed from rye to wheat provided broad resistance against powdery mildew ( Blumeria graminis ). Here, we used quantitative trait locus (QTL) mapping to identify the corresponding wheat mildew avirulence effector AvrPm17 . It is encoded by two paralogous genes that exhibit signatures of reoccurring gene conversion events and are members of a mildew sublineage specific effector cluster. Extensive haplovariant mining in wheat mildew and related sublineages identified several ancient virulent AvrPm17 variants that were present as standing genetic variation in wheat powdery mildew prior to the Pm17 introgression, thereby paving the way for the rapid breakdown of the Pm17 resistance. QTL mapping in mildew identified a second genetic component likely corresponding to an additional resistance gene present on the 1AL.1RS translocation carrying Pm17. This gene remained previously undetected due to suppressed recombination within the introgressed rye chromosomal segment. We conclude that the initial effectiveness of 1AL.1RS was based on simultaneous introgression of two genetically linked resistance genes. Our results demonstrate the relevance of pathogen-based genetic approaches to disentangling complex resistance loci in wheat. We propose that identification and monitoring of avirulence gene diversity in pathogen populations become an integral part of introgression breeding to ensure effective and durable resistance in wheat.
- Published
- 2022
- Full Text
- View/download PDF
38. Severe hepatocellular disease in mice lacking one or both CaaX prenyltransferases[S]
- Author
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Shao H. Yang, Sandy Y. Chang, Yiping Tu, Gregory W. Lawson, Martin O. Bergo, Loren G. Fong, and Stephen G. Young
- Subjects
protein farnesyltransferase ,protein geranylgeranyltransferase ,hyperbilirubinemia ,hepatic steatosis ,prelamin A ,actin stress fibers ,Biochemistry ,QD415-436 - Abstract
Protein farnesyltransferase (FTase) and protein geranylgeranyltransferase-I (GGTase-I) add 15- or 20-carbon lipids, respectively, to proteins that terminate with a CaaX motif. These posttranslational modifications of proteins with lipids promote protein interactions with membrane surfaces in cells, but the in vivo importance of the CaaX prenyltransferases and the protein lipidation reactions they catalyze remain incompletely defined. One study concluded that a deficiency of FTase was inconsequential in adult mice and led to little or no tissue pathology. To assess the physiologic importance of the CaaX prenyltransferases, we used conditional knockout alleles and an albumin–Cre transgene to produce mice lacking FTase, GGTase-I, or both enzymes in hepatocytes. The hepatocyte-specific FTase knockout mice survived but exhibited hepatocellular disease and elevated transaminases. Mice lacking GGTase-I not only had elevated transaminases but also had dilated bile cannaliculi, hyperbilirubinemia, hepatosplenomegaly, and reduced survival. Of note, GGTase-I–deficient hepatocytes had a rounded shape and markedly reduced numbers of actin stress fibers. Hepatocyte-specific FTase/GGTase-I double-knockout mice closely resembled mice lacking GGTase-I alone, but the disease was slightly more severe. Our studies refute the notion that FTase is dispensable and demonstrate that GGTase-I is crucial for the vitality of hepatocytes.
- Published
- 2012
- Full Text
- View/download PDF
39. Utilizing local phase transformation strengthening for nickel-base superalloys
- Author
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Michael J. Mills, A. J. Egan, Nikolai A. Zarkevich, Joshua Stuckner, John W. Lawson, Timothy M. Smith, and Timothy P. Gabb
- Subjects
Materials science ,Alloy ,Stacking ,engineering.material ,Superalloy ,Operating temperature ,Creep ,Mechanics of Materials ,Phase (matter) ,TA401-492 ,engineering ,General Materials Science ,Composite material ,Materials of engineering and construction. Mechanics of materials ,Strengthening mechanisms of materials ,Stacking fault - Abstract
Almost 75 years of research has been devoted to producing superalloys capable of higher operating temperatures in jet turbine engines, and there is an ongoing need to increase operating temperature further. Here, a new disk Nickel-base superalloy is designed to take advantage of strengthening atomic-scale dynamic complexions. This local phase transformation strengthening provides the alloy with a three times improvement in creep strength over similar disk superalloys and comparable strength to a single crystal blade alloy at 760 °C. Ultra-high-resolution chemical mapping reveals that the improvement in creep strength is a result of atomic-scale η (D024) and χ (D019) formation along superlattice stacking faults. To understand these results, the energy differences between the L12 and competing D024 and D019 stacking fault structures and their dependence on composition are computed by density functional theory. This study can help guide researchers to further optimize local phase transformation strengthening mechanisms for alloy development. There is an ongoing need to increase the operating temperature of jet engines, requiring new high-temperature materials. Here, local phase transformations at superlattice stacking faults contribute to a three times improvement in creep strength in a Ni-based superalloy.
- Published
- 2021
40. Plasmodium falciparummalaria during pregnancy: the impact of parasitaemia and anaemia on birthweight
- Author
-
Kingsley Badu, Samuel Kekeli Agordzo, Bernard W. Lawson, Abdul-Hakim Mutala, Christian Kwasi Owusu, and Dawood Ackom Abbas
- Subjects
medicine.medical_specialty ,Pregnancy ,biology ,business.industry ,Obstetrics ,Public health ,Plasmodium falciparum ,Disease ,medicine.disease ,biology.organism_classification ,Miscarriage ,parasitic diseases ,Epidemiology ,medicine ,Adverse effect ,business ,Malaria - Abstract
Malaria in pregnancy remains a major problem of public health concern in Sub-Saharan Africa due to its endemicity and the diverse consequences on both the mother and the baby. Much attention, therefore, is needed to fully understand the epidemiology of the disease and to mitigate the devastating outcomes. The present study aimed at investigating malaria in pregnancy, its adverse effects on pregnant women and the impact on birthweight of babies. A total of 222 pregnant women gave their consent and were recruited into the study during their routine Antenatal care visits. This study employed a combination of cross-sectional and longitudinal cohort study designs. For 122 women in the cross-sectional arm, blood samples and data were obtained once, whilst 100 women in the longitudinal cohort arm were followed up from recruitment until delivery. Demographic information, obstetric history and risk factors were obtained by administering questionnaires. About 1.0 ml of venous blood was drawn to determine malaria parasitaemia and anaemia status of the participants. The birthweights of the babies were also taken at delivery. The prevalence of malaria and anaemia was 19.8% and 27.0% respectively at registration for all 222 participants. All infections wereP. falciparummalaria. One hundred and forty-six (65.8%) of participants had ITN but only 72 (32.4%) used it the previous night. Young age and rural settings were risk factors for malaria. Young age and malaria positive pregnant women had increased risk of anaemia. In the follow-up group which ended with 54 participants, the overall prevalence of malaria and anaemia were 18.7% and 32.4% respectively. Fifty-two (96.3%) of pregnant women attended ANC ≥ 4 times and 55.6% took ≥ 3 doses of SP. There were two cases of miscarriage. Low birthweight occurred in 5.6% of babies. Both malaria and anaemia during pregnancy had no significant impact on birthweight of the babies. Although few of the babies had low birthweight, this number can be further reduced when pregnant women attend ANC and take SP at the recommended number of times.
- Published
- 2021
41. Regeneration and growth in crowns and rhizome fragments of Japanese knotweed (Reynoutria japonica) and desiccation as a potential control strategy
- Author
-
Mark W. Smith, Jacob W. Lawson, Karen L. Bacon, and Mark Fennell
- Subjects
Nodes ,Plant Science ,General Biochemistry, Genetics and Molecular Biology ,Japonica ,Invasive species ,Regeneration ,Desiccation ,Regeneration (ecology) ,biology ,Ecology ,Crowns ,Reynoutria japonica ,General Neuroscience ,food and beverages ,General Medicine ,biology.organism_classification ,Medium scale ,Rhizomes ,Rhizome ,Management ,Horticulture ,Management strategy ,Japanese knotweed ,Medicine ,General Agricultural and Biological Sciences - Abstract
Reynoutria japonica (Japanese knotweed) is a problematic invasive plant found in many areas of Europe and North America. Notably, in the UK, the species can cause issues with mortgage acquisition. Control of R. japonica is complicated by its ability to regenerate from small fragments of plant material; however, there remains uncertainty about how much (in terms of mass) rhizome is required for successful regeneration. This study investigated the ability of crowns and rhizomes with different numbers of nodes to regenerate successfully from three sites in the north of England, UK. Two of the sites had been subject to herbicide treatment for two years prior to sampling and the third site had no history of herbicide treatment. No significant differences were observed in regenerated stem diameter, maximum height of stem and maximum growth increments among crowns. All traits measured from the planted crowns were significantly greater than those of the planted rhizome fragments and at least one node was necessary for successful regeneration of rhizomes. The smallest initial fragment weight to regenerate and survive the experiment was 0.5 g. Subjecting all plant material to desiccation for 38 days resulted in no regrowth (emergence or regeneration) after replanting. These findings suggest that desiccation could be a valuable management strategy for small to medium scale infestations common in urban settings.
- Published
- 2021
42. Discovery of novel Li SSE and anode coatings using interpretable machine learning and high-throughput multi-property screening
- Author
-
Xin Yang, Hideyuki Komatsu, Atsushi Ohma, Kuwata Shigemasa, John W. Lawson, Shreyas Honrao, Balachandran Radhakrishnan, and Maarten Sierhuis
- Subjects
Multidisciplinary ,Computer science ,business.industry ,Science ,Stability (learning theory) ,Machine learning ,computer.software_genre ,Ensemble learning ,Article ,Anode ,Batteries ,Feature (machine learning) ,Fast ion conductor ,Computational methods ,Medicine ,Gradient boosting ,Artificial intelligence ,business ,Throughput (business) ,computer ,Interpretability - Abstract
All-solid-state batteries with Li metal anode can address the safety issues surrounding traditional Li-ion batteries as well as the demand for higher energy densities. However, the development of solid electrolytes and protective anode coatings possessing high ionic conductivity and good stability with Li metal has proven to be a challenge. Here, we present our informatics approach to explore the Li compound space for promising electrolytes and anode coatings using high-throughput multi-property screening and interpretable machine learning. To do this, we generate a database of battery-related materials properties by computing $$\hbox {Li}^+$$ Li + migration barriers and stability windows for over 15,000 Li-containing compounds from Materials Project. We screen through the database for candidates with good thermodynamic and electrochemical stabilities, and low $$\hbox {Li}^+$$ Li + migration barriers, identifying promising new candidates such as $$\hbox {Li}_9\hbox {S}_3$$ Li 9 S 3 N, $$\hbox {LiAlB}_2\hbox {O}_5$$ LiAlB 2 O 5 , $$\hbox {LiYO}_2$$ LiYO 2 , $$\hbox {LiSbF}_4$$ LiSbF 4 , and $$\hbox {Sr}_4\hbox {Li}(\hbox {BN}_2)_3$$ Sr 4 Li ( BN 2 ) 3 , among others. We train machine learning models, using ensemble methods, to predict migration barriers and oxidation and reduction potentials of these compounds by engineering input features that ensure accuracy and interpretability. Using only a small number of features, our gradient boosting regression models achieve $$\mathrm {R}^2$$ R 2 values of 0.95 and 0.92 on the oxidation and reduction potential prediction tasks, respectively, and 0.86 on the migration barrier prediction task. Finally, we use Shapley additive explanations and permutation feature importance analyses to interpret our machine learning predictions and identify materials properties with the largest impact on predictions in our models. We show that our approach has the potential to enable rapid discovery and design of novel solid electrolytes and anode coatings.
- Published
- 2021
43. Correction to: CLUSTER ALGEBRAS FROM SURFACES AND EXTENDED AFFINE WEYL GROUPS
- Author
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Anna Felikson, John W. Lawson, Michael Shapiro, and Pavel Tumarkin
- Subjects
Pure mathematics ,Algebra and Number Theory ,Geometry and Topology ,Affine transformation ,Algebra over a field ,Cluster algebra ,Mathematics - Published
- 2021
44. Proton Abstraction from DMEn···X+ by OH–, O2–, and XO2–, for X = Li, Na, and K: Implications for Li–O2 Batteries
- Author
-
Charles W. Bauschlicher, Ewa Papajak, Justin B. Haskins, and John W. Lawson
- Subjects
010304 chemical physics ,Proton ,Chemistry ,Binding energy ,010402 general chemistry ,Alkali metal ,01 natural sciences ,Solution phase ,0104 chemical sciences ,Solvent ,Turn (biochemistry) ,0103 physical sciences ,Physical chemistry ,Molecule ,Density functional theory ,Physical and Theoretical Chemistry - Abstract
The abstraction of a proton by OH-, O2-, and XO2- from DME n···X+, where X is Li, Na, or K, is studied using density functional theory. Both the gas phase and the solution phase are studied. In general, when explicit solvent molecules are added, the difference between the gas-phase and solution results becomes rather small. While the DME n···X+ binding energies differ significantly for various alkali cations, the reaction energies and transition-state energies are far less sensitive to the choice of an alkali cation. XO2- has a lower barrier height than OH-, which, in turn, has a lower barrier height than O2-. The reaction energies follow the same trends.
- Published
- 2019
45. Parent–offspring conflict unlikely to explain ‘child marriage’ in northwestern Tanzania
- Author
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Susan B. Schaffnit, David W. Lawson, Anushé Hassan, and Mark Urassa
- Subjects
0303 health sciences ,Social Psychology ,media_common.quotation_subject ,Experimental and Cognitive Psychology ,Coercion ,Social security ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,Child marriage ,Normative ,Demographic economics ,Sociology ,Parent–offspring conflict ,International development ,030217 neurology & neurosurgery ,Autonomy ,030304 developmental biology ,Forced marriage ,media_common - Abstract
Approximately 40% of women in sub-Saharan Africa marry before their eighteenth birthday1. Within the international development sector, this phenomenon is referred to as 'child marriage', widely equated to forced marriage, and recognized as damaging to multiple dimensions of female well-being1,2. An escalating global campaign to end early marriage typically assumes that its high prevalence is driven by a conflict of interests between parents and daughters, with parents coercing daughters to marry early for the parents' economic benefit3. However, a parent-offspring conflict model of early marriage has not been explicitly tested. Here we present a study of marriage transitions in rural Tanzania, where marriage before or just after 18 years of age is normative. Consistent with parental coercion, we find that bridewealth transfers are highest for younger brides. However, autonomy in partner choice is very common at all ages, relationships between age at marriage and female well-being are largely equivocal, and women who marry early achieve relatively higher reproductive success. We conclude that, in contexts in which adolescents have autonomy in marriage choices and in which marriage promotes economic and social security, early marriage may be better understood as serving the strategic interests of both parents and daughters.
- Published
- 2019
46. 'Child marriage' in context: exploring local attitudes towards early marriage in rural Tanzania
- Author
-
Mark Urassa, Susan B. Schaffnit, and David W. Lawson
- Subjects
Adult ,Male ,Rural Population ,early marriage ,adulthood ,Adolescent ,Urban Population ,media_common.quotation_subject ,Exploratory research ,tanzania ,Poison control ,Context (language use) ,Tanzania ,young people ,Young Adult ,Child marriage ,Humans ,Sociology ,Marriage ,Research Articles ,media_common ,HQ1-2044 ,east Africa ,Obstetrics and Gynecology ,Gender studies ,Focus Groups ,Focus group ,Diseases of the genitourinary system. Urology ,Local community ,Sexual Partners ,Attitude ,Reproductive Medicine ,The family. Marriage. Woman ,Female ,adolescence ,RC870-923 ,Autonomy ,Research Article ,east africa ,Social status - Abstract
A global campaign to end “child marriage” has emerged over the last decade as part of growing international commitments to address gender inequities and improve female wellbeing. Campaigns typically assert that young brides have negligible autonomy in the marriage process and that marrying under 18 years has resolutely negative impacts on wellbeing. Yet, surprisingly few studies explore local attitudes towards marriage and its timing within contexts where early marriage is most common. As such our understanding of motivations and potential conflicts of interest leading female adolescents into marriage remain poorly informed by viewpoints of people purportedly at risk. We present an exploratory study of attitudes to early marriage in northwestern Tanzania where marriage before or shortly after 18 years is normative. We use focus group discussions, complimented by a survey of 993 women, to investigate local views on marriage. We explore (i) why people marry, (ii) when marriage is deemed appropriate, and (iii) who guides the marriage process. Contrary to dominant narratives in the end child marriage movement, we find that women are frequently active rather than passive in the selection of when and who to marry. Furthermore, marriage is widely viewed as instrumental in acquiring social status within one’s local community. Our conclusions illuminate why rates of early marriage remain high despite potential negative wellbeing consequences and increasingly restrictive laws. We discuss our results in relation to related qualitative studies in other cultural contexts and consider the policy implications for current efforts to limit early marriage in Tanzania and beyond.
- Published
- 2019
47. In Utero Exposure to Benzo[ a ]pyrene Induces Ovarian Mutations at Doses That Deplete Ovarian Follicles in Mice
- Author
-
Matthew J. Meier, Ulrike Luderer, Marc A. Beal, Carole L. Yauk, Gregory W. Lawson, and Francesco Marchetti
- Subjects
Epidemiology ,Health, Toxicology and Mutagenesis ,Mutagen ,010501 environmental sciences ,Toxicology ,medicine.disease_cause ,Medical and Health Sciences ,01 natural sciences ,Mice ,chemistry.chemical_compound ,Ovarian Follicle ,Pregnancy ,critical window ,Maternal-Fetal Exchange ,Genetics (clinical) ,Cancer ,Pediatric ,0303 health sciences ,Biological Sciences ,Ovarian Cancer ,medicine.anatomical_structure ,Lac Operon ,Benzo(a)pyrene ,Maternal Exposure ,In utero ,Prenatal Exposure Delayed Effects ,Environmental Pollutants ,Female ,Pediatric Research Initiative ,endocrine system ,transplacental ,animal structures ,Ovary ,Biology ,Article ,Andrology ,03 medical and health sciences ,Follicle ,Rare Diseases ,polycyclic aromatic hydrocarbon ,medicine ,Animals ,030304 developmental biology ,0105 earth and related environmental sciences ,Transplacental ,chemistry ,Mutation ,ovary ,Bone marrow ,Carcinogenesis ,Environmental Sciences ,Mutagens - Abstract
Polycyclic aromatic hydrocarbons like benzo[a]pyrene (BaP) are ubiquitous environmental contaminants formed during incomplete combustion of organic materials. Our prior work showed that transplacental exposure to BaP depletes ovarian follicles and increases prevalence of epithelial ovarian tumors later in life. We used the MutaMouse transgenic rodent model to address the hypothesis that ovarian mutations play a role in tumorigenesis caused by prenatal exposure to BaP. Pregnant MutaMouse females were treated with 0, 10, 20, or 40 mg/(kg day) BaP orally on gestational days 7-16, covering critical windows of ovarian development. Female offspring were euthanized at 10 weeks of age; some ovaries with oviducts were processed for follicle counting; other ovaries/oviducts and bone marrow were processed for determination of lacZ mutant frequency (MF). Mutant plaques were pooled within dose groups and sequenced to determine the mutation spectrum. BaP exposure caused highly significant dose-related decreases in ovarian follicles and increases in ovarian/oviductal and bone marrow mutant frequencies at all doses. Absence of follicles, cell packets, and epithelial tubular structures were observed with 20 and 40 mg/(kg day) BaP. Depletion of ovarian germ cells was inversely associated with ovarian MF. BaP induced primarily G > T and G > C transversions and deletions in ovaries/oviducts and bone marrow cells and produced a mutation signature highly consistent with that of tobacco smoking in human cancers. Overall, our results show that prenatal BaP exposure significantly depletes ovarian germ cells, causes histopathological abnormalities, and increases the burden of ovarian/oviductal mutations, which may be involved in pathogenesis of epithelial ovarian tumors. Environ. Mol. Mutagen. 60:410-420, 2019. © 2018 Her Majesty the Queen in Right of Canada.
- Published
- 2018
48. Reaction of Singlet Oxygen with the Ethylene Group: Implications for Electrolyte Stability in Li-Ion and Li-O
- Author
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J Wayne, Mullinax, Charles W, Bauschlicher, and John W, Lawson
- Abstract
Recent experimental and computational evidence indicates that singlet oxygen (
- Published
- 2021
49. He for she? Variation and exaggeration in men's support for women's empowerment in northern Tanzania
- Author
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Yusufu Kumogola, Susan B. Schaffnit, David W. Lawson, Mark Urassa, Joseph A. Kilgallen, and Anthony Galura
- Subjects
Cultural Studies ,biology ,media_common.quotation_subject ,05 social sciences ,Patriarchy ,Wage labour ,biology.organism_classification ,03 medical and health sciences ,0302 clinical medicine ,Tanzania ,Anthropology ,Women's empowerment ,0502 economics and business ,Global health ,Wife ,030212 general & internal medicine ,050207 economics ,Empowerment ,Psychology ,Socioeconomic status ,Applied Psychology ,Ecology, Evolution, Behavior and Systematics ,Demography ,media_common - Abstract
Achieving gender equality fundamentally requires a transfer of power from men to women. Yet data on men's support for women's empowerment (WE) remains scant and limited by reliance on self-report methodologies. Here, we examine men's support for WE as a sexual conflict trait, both via direct surveys (n = 590) and indirectly by asking men's wives (n = 317) to speculate on their husband's views. Data come from a semi-urban community in Mwanza, Tanzania. Consistent with reduced resource competition and increased exposure to relatively egalitarian gender norms, higher socioeconomic status predicted greater support for WE. However, potential demographic indicators of sexual conflict (high fertility, polygyny, large spousal age gap) were largely unrelated to men's support for WE. Contrasting self- and wife-reported measures suggests that men frequently exaggerate their support for women in self-reported attitudes. Discrepancies were especially pronounced among men claiming the highest support for WE, but smallest among men who held a professional occupation and whose wife participated in wage labour, indicating that these factors predict genuine support for WE. We discuss the implications of these results for our understanding of both individual variation and patriarchal gender norms, emphasising the benefits of greater exchange between the evolutionary human sciences and global health research on these themes.
- Published
- 2021
50. Transcriptomic profiles of non-embryogenic and embryogenic callus cells in a highly regenerative upland cotton line (Gossypium hirsutum L.)
- Author
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Zhigang Li, Wei Li, Don C. Jones, Stephen Parris, John W. Lawson, Michael Smathers, Li Wen, Matthew West, Shuangxia Jin, and Christopher A. Saski
- Subjects
0106 biological sciences ,Plant Somatic Embryogenesis Techniques ,Somatic embryogenesis ,Biology ,01 natural sciences ,Transcriptome ,03 medical and health sciences ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Plant Cells ,Gene expression ,Transcription factor ,Gene ,Leafy ,lcsh:QH301-705.5 ,030304 developmental biology ,Plant Proteins ,0303 health sciences ,Gossypium ,Callus, embryo ,DNA Methylation ,Cell biology ,lcsh:Biology (General) ,Callus ,Gossypium hirsutum L ,Developmental biology ,010606 plant biology & botany ,Developmental Biology ,Research Article ,Signal Transduction ,Transcription Factors - Abstract
BackgroundGenotype independent transformation and whole plant regeneration through somatic embryogenesis relies heavily on the intrinsic ability of a genotype to regenerate. The critical genetic architecture of non-embryogenic callus (NEC) cells and embryogenic callus (EC) cells in a highly regenerable cotton genotype is unknown.ResultsIn this study, gene expression profiles of a highly regenerableGossypium hirsutumL. cultivar, Jin668, were analyzed at two critical developmental stages during somatic embryogenesis, non-embryogenic callus (NEC) cells and embryogenic callus (EC) cells. The rate of EC formation in Jin668 is 96%. Differential gene expression analysis revealed a total of 5333 differentially expressed genes (DEG) with 2534 genes upregulated and 2799 genes downregulated in EC. A total of 144 genes were unique to NEC cells and 174 genes were unique to EC. Clustering and enrichment analysis identified genes upregulated in EC that function as transcription factors/DNA binding, phytohormone response, oxidative reduction, and regulators of transcription; while genes categorized in methylation pathways were downregulated. Four key transcription factors were identified based on their sharp upregulation in EC tissue;LEAFY COTYLEDON 1(LEC1),BABY BOOM(BBM),FUSCA(FUS3) andAGAMOUS-LIKE15with distinguishable subgenome expression bias.ConclusionsThis comparative analysis of NEC and EC transcriptomes gives new insights into the genes involved in somatic embryogenesis in cotton.
- Published
- 2020
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