55 research outputs found
Faster Family-wise Error Control for Neuroimaging with a Parametric Bootstrap
In neuroimaging, hundreds to hundreds of thousands of tests are performed
across a set of brain regions or all locations in an image. Recent studies have
shown that the most common family-wise error (FWE) controlling procedures in
imaging, which rely on classical mathematical inequalities or Gaussian random
field theory, yield FWE rates that are far from the nominal level. Depending on
the approach used, the FWER can be exceedingly small or grossly inflated. Given
the widespread use of neuroimaging as a tool for understanding neurological and
psychiatric disorders, it is imperative that reliable multiple testing
procedures are available. To our knowledge, only permutation joint testing
procedures have been shown to reliably control the FWER at the nominal level.
However, these procedures are computationally intensive due to the increasingly
available large sample sizes and dimensionality of the images, and analyses can
take days to complete. Here, we develop a parametric bootstrap joint testing
procedure. The parametric bootstrap procedure works directly with the test
statistics, which leads to much faster estimation of adjusted \emph{p}-values
than resampling-based procedures while reliably controlling the FWER in sample
sizes available in many neuroimaging studies. We demonstrate that the procedure
controls the FWER in finite samples using simulations, and present region- and
voxel-wise analyses to test for sex differences in developmental trajectories
of cerebral blood flow
Evaluation du pouvoir disjonctif des variables catĂ©gorielles impliquĂ©es dans la sĂ©lection du palmier Ă huile (Elaeis guineensis jacq.) en CĂŽte dâIvoire
En amĂ©lioration gĂ©nĂ©tique du palmier Ă huile (Elaeis guineensis Jacq.), les variables catĂ©gorielles constituent une part majoritaire de lâinformation utilisĂ©e pour diffĂ©rencier, les populations de gĂ©niteurs issus du programme de sĂ©lection rĂ©currente rĂ©ciproque (SRR). Le pouvoir disjonctif de ces variables a Ă©tĂ© testĂ© sur 134 gĂ©niteurs sĂ©lectionnĂ©s issus des populations du premier, deuxiĂšme et troisiĂšme cycle de SRR. Les variables catĂ©gorielles utilisĂ©es pour diffĂ©rencier ces populations sont celles qui ont permis dâavoir des informations sur les origines gĂ©ographiques et les gĂ©nĂ©alogies parentales des gĂ©niteurs. Lâanalyse factorielle de lâensemble de ces variables catĂ©gorielles, a permis de dĂ©terminer le pouvoir disjonctif de chacun des deux principaux critĂšres de divergences des populations de gĂ©niteurs sĂ©lectionnes. Le critĂšre "origine gĂ©ographique" a reprĂ©sentĂ© 14 % dâexpression de disjonction totale des populations de gĂ©niteurs sĂ©lectionnĂ©s. Le critĂšre "gĂ©nĂ©alogie parentale" a reprĂ©sentĂ© 70 % dâexpression de disjonction totale des populations de gĂ©niteurs sĂ©lectionnĂ©s. Lâutilisation de ces deux critĂšres de diffĂ©renciation des populations de gĂ©niteurs sĂ©lectionnĂ©es peut constituer une bonne alternative Ă lâutilisation des donnĂ©es molĂ©culaires dans les Ă©tudes de la diversitĂ© des populations de palmier Ă huile en sĂ©lection.Mots-clĂ©s : Palmier Ă huile, sĂ©lection, variable catĂ©gorielle, disjonction de populatio
Blame framing and prior knowledge influence moral judgments for people involved in the Tulsa Race Massacre among a combined Oklahoma and UK sample
IntroductionHow an event is framed impacts how people judge the morality of those involved, but prior knowledge can influence information processing about an event, which also can impact moral judgments. The current study explored how blame framing and self-reported prior knowledge of a historical act of racial violence, labeled as Riot, Massacre, or Event, impacted individualâs cumulative moral judgments regarding the groups involved in the Tulsa Race Massacre (Black Tulsans, the Tulsa Police, and White Tulsans).Methods and resultsThis study was collected in two cohorts including undergraduates attending the University of Oklahoma and individuals living in the United Kingdom. Participants were randomly assigned to a blame framing condition, read a factual summary of what happened in Tulsa in 1921, and then responded to various moral judgment items about each group. Individuals without prior knowledge had higher average Likert ratings (more blame) toward Black Tulsans and lower average Likert ratings (less blame) toward White Tulsans and the Tulsa Police compared to participants with prior knowledge. This finding was largest when what participants read was framed as a Massacre rather than a Riot or Event. We also found participants with prior knowledge significantly differed in how they made moral judgments across target groups; those with prior knowledge had lower average Likert ratings (less blame) for Black Tulsans and higher average Likert ratings (more blame) for White Tulsans on items pertaining to causal responsibility, intentionality, and punishment compared to participants without prior knowledge.DiscussionFindings suggest that the effect of blame framing on moral judgments is dependent on prior knowledge. Implications for how people interpret both historical and new events involving harmful consequences are discussed
Trends and seasonal variability in ammonia across major biomes in western and central Africa inferred from long-term series of ground-based and satellite measurements
Ammonia (NH3) is the most abundant alkaline
component in the atmosphere. Changes in NH3 concentrations have
important implications for atmospheric chemistry, air quality, and ecosystem
integrity. We present a long-term ammonia (NH3) assessment in the
western and central African regions within the framework of the International
Network to study Deposition and Atmospheric chemistry in Africa (INDAAF)
programme. We analyse seasonal variations and trends in NH3
concentrations and total column densities along an African ecosystem
transect spanning dry savannas in Banizoumbou, Niger, and Katibougou, Mali;
wet savannas in Djougou, Benin, and Lamto, CÎte d'Ivoire; and forests in Bomassa, Republic of the Congo, and Zoétélé, Cameroon. We use a
21-year record of observations (1998â2018) from INDAAF passive samplers and an 11-year record of observations (2008â2018) of atmospheric vertical column densities from the Infrared Atmospheric Sounding Interferometer (IASI) to evaluate NH3 ground-based concentrations and total column densities,
respectively. Climatic data (air temperature, rainfall amount, and leaf area
index), as well as ammonia emission data of biomass combustion from the
fourth version of the Global Fire Emissions Database (GFED4) and
anthropogenic sources from the Community Emissions Data System (CEDS), were
compared with total NH3 concentrations and total columns over the same
periods. Annual mean ground-based NH3 concentrations are around 5.7â5.8âppb in dry savannas, 3.5â4.7âppb in wet savannas, and 3.4â5.6âppb in forests. Annual IASI NH3 total column densities are 10.0â10.7âĂâ1015âmolec.âcmâ2 in dry savanna, 16.0â20.9âĂâ1015âmolec.âcmâ2 in wet
savanna, and 12.4â13.8âĂâ1015âmolec.âcmâ2 in forest stations. Non-parametric statistical MannâKendall trend tests applied to annual data show that ground-based NH3 concentrations increase at Bomassa (+2.56â%âyrâ1) but decrease at ZoĂ©tĂ©lĂ© (â2.95â%âyrâ1) over the 21-year period. The 11-year period of IASI NH3 total column density measurements show yearly increasing trends at Katibougou (+3.46â%âyrâ1), Djougou (+2.24â%âyrâ1), and ZoĂ©tĂ©lĂ© (+3.42â%âyrâ1). From the outcome of our
investigation, we conclude that air temperature, leaf area index, and
rainfall combined with biomass burning, agricultural, and residential
activities are the key drivers of atmospheric NH3 in the INDAAF
stations. The results also show that the drivers of trends are (1)Â agriculture in the dry savanna of Katibougou; (2)Â air temperature and agriculture in the wet savanna of Djougou and Lamto; and (3)Â leaf area index, air temperature, residential, and agriculture in the forest of Bomassa.</p
QTL detection by multi-parent linkage mapping in oil palm (Elaeis guineensis Jacq.)
A quantitative trait locus (QTL) analysis designed for a multi-parent population was carried out and tested in oil palm (Elaeis guineensis Jacq.), which is a diploid cross-fertilising perennial species. A new extension of the MCQTL package was especially designed for crosses between heterozygous parents. The algorithm, which is now available for any allogamous species, was used to perform and compare two types of QTL search for small size families, within-family analysis and across-family analysis, using data from a 2Â ĂÂ 2 complete factorial mating experiment involving four parents from three selected gene pools. A consensus genetic map of the factorial design was produced using 251 microsatellite loci, the locus of the Sh major gene controlling fruit shell presence, and an AFLP marker of that gene. A set of 76 QTLs involved in 24 quantitative phenotypic traits was identified. A comparison of the QTL detection results showed that the across-family analysis proved to be efficient due to the interconnected families, but the family size issue is just partially solved. The identification of QTL markers for small progeny numbers and for marker-assisted selection strategies is discussed
Molecular variability from two selection of BRT10 population in an inbreeding program of oil palm (Elaeis guineensis Jacq.) in CĂŽte dâIvoire
Genetic variability of two groups of palms composed with four progenies selected in BRT10 improved populations resulting from successive self-fertilizations of two parents LM2T and LM10T was studiedusing four polymorphic microsatellites DNA markers of Elaeis guineensis Jacq. The molecular variability of those progenies was analyzed and genetic diversity of each group of palms was deduced.The results of analysis of molecular variance revealed that 59.68% of variance can be explained by palms within each progeny, while 31.24% of total variance was partitioned between the two groups ofpalms. The program selection of self-fertilizations has created a distinct molecular structure within BRT10 improved populations resulting from LM2T and LM10T. Molecular analysis showed that thepartitioning of variance in this breeding program was higher among palms within each progeny than among the two groups of palms. Only the exploitation of molecular data revealed the truly diversifiedprogeny. The use of molecular data analysis in support with agro-morphological assessment should improve the cross performance while maintaining the genetic variation for further progress insubsequent selection cycles
Modelling landâatmosphere daily exchanges of NO, NH<sub>3</sub>, and CO<sub>2</sub> in a semi-arid grazed ecosystem in Senegal
Three different models (STEPâGENDECâNOflux, Zhang2010, and Surfatm)
are used to simulate NO, CO2, and NH3 fluxes at the daily
scale for 2 years (2012â2013) in a semi-arid grazed ecosystem at Dahra
(15â24âČ10âČâČ N, 15â25âČ56âČâČ W, Senegal, Sahel). Model
results are evaluated against experimental results acquired during three
field campaigns. At the end of the dry season, when the first rains re-wet the
dry soils, the model STEPâGENDECâNOflux simulates the sudden mineralization of
buried litter, leading to pulses in soil respiration and NO fluxes. The
contribution of wet season fluxes of NO and CO2 to the annual mean
is respectively 51 % and 57 %. NH3 fluxes are simulated by
two models: Surfatm and Zhang2010. During the wet season, air humidity and
soil moisture increase, leading to a transition between low soil
NH3 emissions (which dominate during the dry months) and large
NH3 deposition on vegetation during wet months. Results show a
great impact of the soil emission potential, a difference in the deposition
processes on the soil and the vegetation between the two models with however
a close agreement of the total fluxes. The order of magnitude of NO,
NH3, and CO2 fluxes is correctly represented by the
models, as well as the sharp transitions between seasons, specific to the
Sahel region. The role of soil moisture in flux magnitude is highlighted,
whereas the role of soil temperature is less obvious. The simultaneous
increase in NO and CO2 emissions and NH3 deposition at
the beginning of the wet season is attributed to the availability of mineral
nitrogen in the soil and also to microbial processes, which distribute the
roles between respiration (CO2 emissions), nitrification (NO
emissions), volatilization, and deposition (NH3
emission/deposition). The objectives of this study are to understand the
origin of carbon and nitrogen compounds exchanges between the soil and the
atmosphere and to quantify these exchanges on a longer timescale when only a
few measurements have been performed.</p
Assessment of various strategies for the preservation of clonal genetic resources in oil-palm (Elaeis guineensis Jacq.)
Three different approaches for the preservation of oil palm (Elaeis guineensis Jacq.) clonal genetic resources and their impacts on the induction of the « mantled » somaclonal variation were assessed. In vitro long term preservation of somatic embryos stock-cultures was studied : after a 5 year cultivation period, 75 % of clonal lines were still normal. Between 8 and 13 years of embryo cultures, half of the considered clonal lines were found to be « mantled ». Finally, 40 % were found to be normal over 15 years of in vitro conservation. Clonal conformity of ramets resulting from the re-cloning of somaplants depended, on one hand, on the floral status of the mother plant at the time of sampling and, on the other hand, on its origin. Re-cloning of abnormal regenerants led, in all cases, to 100 % abnormal offspring. The age of the ramet used as mother palm at the time of sampling was found to be critical for true-to-type regeneration. There is a high risk of obtaining variant regenerant palms if the clonal mother palm is sampled at nursery stage. Field observations carried out on palms originating from somatic embryos cryopreserved at -196 °C showed floral conformity rates comparable to those obtained from standard not-cryopreserved clonal palms, for 6 out of the 8 clonal lines studied. From the 2 remaining clonal lines, a few regenerant palms originating from standard batch were found to be « mantled », whereas those resulting from cryopreserved embryos were all normal. The
assumption of changes in levels of genomic DNA methylation during preservation was discussed, together with the capacity of our cryopreservation protocol to select embryogenic cells which were only suited to trueto- type regeneration.Trois approches de conservation des ressources gĂ©nĂ©tiques clonales de palmier Ă huile (Elaeis guineensis Jacq.) ont Ă©tĂ© testĂ©es et leurs incidences sur l\'induction de la variation somaclonale « mantled » ont Ă©tĂ© Ă©valuĂ©es. La conservation in vitro Ă long terme des souches d\'embryons somatiques a montrĂ© qu\'aprĂšs 5 ans de culture, 75 % des clones Ă©taient encore normaux. Entre 8 et 13 ans de culture, la moitiĂ© des clones a prĂ©sentĂ© des plants Ă floraison anormale « mantled ». Finalement, 40 % des clones Ă©taient toujours normaux mĂȘme aprĂšs 15 ans de conservation in vitro. La conformitĂ© florale des plants issus
de reclonage de vitroplants dĂ©pend, d\'une part, du statut floral du palmier donneur au moment de son utilisation et, d\'autre part ,de l\'origine de la lignĂ©e clonale Ă laquelle il appartient. Le reclonage de rĂ©gĂ©nĂ©rants anormaux a conduit, dans tous les cas, Ă 100 % de descendances anormales. L\'Ăąge du vitro plant donneur au moment de son prĂ©lĂšvement semble ĂȘtre essentiel pour l\'obtention d\'une rĂ©gĂ©nĂ©ration conforme. Un grand risque d\'obtention de rĂ©gĂ©nĂ©rants variants existe si le plant utilisĂ© est prĂ©levĂ© au stade pĂ©piniĂšre. Les observations rĂ©alisĂ©es sur les palmiers issus d\'embryons cryoconservĂ©s Ă -196 °C ont montrĂ© des taux de conformitĂ© florale comparables Ă ceux issus d\'embryons tĂ©moins non congelĂ©s, pour 6 des 8 clones Ă©tudiĂ©s. Pour les 2 autres clones, quelques plants issus d\'embryons tĂ©moins ont prĂ©sentĂ© la variation florale « mantled », alors que ceux issus d\'embryons cryo-conservĂ©s ont tous Ă©tĂ© normaux. L\'hypothĂšse d\'une modification du niveau de mĂ©thylation de l\'ADN gĂ©nomique au cours de la durĂ©e de la conservation a Ă©tĂ© discutĂ©e et la capacitĂ© de notre protocole de cryoconservation Ă sĂ©lectionner les cellules embryogĂšnes aptes Ă une rĂ©gĂ©nĂ©ration conforme de plants. Keywords:In situ preservation, « mantled » floral abnormality, somaclonal variation, somatic embryogenesis, oil palm, CĂŽte d\'IvoireAgronomie Africaine Vol. 18 (3) 2006: pp. 187-20
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