458 research outputs found
Flight test evaluation of a method to determine the level flight performance of a propeller-driven aircraft
The overall drag of the aircraft is expressed in terms of the measured increment of power required to overcome a corresponding known increment of drag, which is generated by a towed drogue. The simplest form of the governing equations, D = delta D SHP/delta SHP, is such that all of the parameters on the right side of the equation can be measured in flight. An evaluation of the governing equations has been performed using data generated by flight test of a Beechcraft T-34B. The simplicity of this technique and its proven applicability to sailplanes and small aircraft is well known. However, the method fails to account for airframe-propulsion system
Measuring the success of \u3ci\u3eClassWorks\u3c/i\u3e computer instruction
The purpose of this research was to test the effectiveness of the computer program, ClassWorks Gold (CW) in improving student reading and writing scores. ClassWorks Gold is a computer program that merges parts of 150 commercially available language arts program with a built-in assessment and internal e-mail system.
Garfield Elementary School in Cedar Rapids, Iowa, received a grant from the Iowa Department of Education for the purchase and implementation of CW as a supplement to regular language arts classroom instruction. The grant required action research for an assessment. This paper focuses on the effectiveness of CW with two third grade classes in one school year.
All third grade students were given the same computer ClassWorks pretest. Students began at level one and continued through the automated test until they missed three questions. The score was recorded and students began at the last level theysuccessfully passed.
Students then spent 45 minutes twice a week for 28 weeks interacting with the ClassWorks software. ClassWorks individualized instruction in a variety of language arts concepts. A concept was presented, defined, and examples given. Students then completed a series of lessons and given a quiz. Passage of the quiz at 80% allowed students to move on to the next concept. A score of less than 80% placed the student in remediation with further examples and lessons followed by another quiz.
The computer program recorded the time students spent on each sub-section of the unit and any quiz scores. Teachers, however, had to record the scores for the projects. These scores were recorded in C/assWorks assessment program. The same placement test administered as a pretest was given as a posttest to determine academic progress.
In October students were also given the Iowa Tests of Basic Skills. The same test was administered again in May to assess academic growth. This is a norm-referenced test. While these two tests do not evaluate in the same manner, the results of both were used to compare the overall academic progress of the students in the area of language arts.
A comparison of growth between the pre and posttests was done to determine the effectiveness of the CW program.
Hypothesis 1 predicted that this group of students would make six months academic growth over the established baseline of previous Garfield third graders who were taught with traditional methods of instruction as evidenced by both the !TBS andClassWorks Gold GLE evaluation. Findings showed hypothesis 1 was nil. Students using ClassWorks made three months growth over one previous class and ten months growth over another previous class above the baseline average on ITBS Tests. However, spring data were lacking from a third year for comparison. There is not sufficient data for a concrete comparison. No baseline average was available for ClassWorks since this was the initial implementation.
Hypothesis 2: Student academic progress would have a significant positive correlation to time on task. Students who spend more time in ClassWorks will show greater academic growth than those that spent less time on task. There will be an uneven amount of growth when comparing student to student; since the population is made up of delayed, average, and proficient students. Time on task was monitored by the internal assessment management system (AMS) within ClassWorks. Findings show hypothesis 2was accepted. Those students who did not make improvement on ClassWorks appeared to rush through the tests, made many guesses, or used the Don \u27t Know option many times. Those students who spent more time on task did do better on the tests.
Hypothesis 3: Weekly teacher evaluation of student progress is directly related to student achievement. Therefore, those teachers who weekly monitor the quizzes and projects within the ClassWorks system, and enhance or remediate the language arts concepts with direct classroom instruction will have students who show greater academic growth. Findings for hypothesis 3 were inconclusive. Students who were identified by ClassWorks as needing remediation in specific skills were not given remediation of those specifically identified skills. Remediation was done as it related to the district language arts curriculum. Hypothesis three can neither be accepted nor rejected.
In this study the lack of alignment between the ClassWorks skills in need of remediation and the district language arts curriculum skills actually taught and remediated in the classroom makes it impossible to determine how effective the role ofthe teacher was in this computer-aided instruction. CAI instruction is generally too costly and time consuming to be used merely as a skill building tool. Remediation is a critical piece in which the teacher must take an active role. Teachers need time to plan if they are delving deeply into this integration; or the software program needs to be aligned with thecurriculum before it is purchased.
Students became bored with the program as evidenced by verbal comments, an increase in the number of Don \u27t Know test responses, the shortened time students spent working on assessments, and the lack of quality in student projects.
ClassWorks provides a different kind of test data than Iowa Test of Basic Skills. ClassWorks is not a standardized normed test. Without further research it is impossible to tell if the ClassWorks program was responsible for the increased in ITBS scores.
Clearly, there is room for more study. There are opponents and proponents of CAI instruction in the classroom and as many strategies for effective presentation there are supporters or naysayers. Certainly higher-order thinking skills and multi-media methods must be involved to keep CAI out of the ancient educational realm of skill and drill
Stress Drop Variation of DeepâFocus Earthquakes Based on Empirical Greenâs Functions
We analyze source characteristics of global, deepâfocus (>350Â km) earthquakes with moment magnitudes (Mw) larger than 6.0â8.2 using teleseismic Pâwave and Sâwave spectra and an empirical Greenâs functions approach. We estimate the corner frequency assuming Bruneâs source model and calculate stress drops assuming a circular crack model. Based on Pâwave and Sâwave spectra, the one standard deviation ranges are 3.5â369.8 and 8.2â328.9Â MPa, respectively. Based on the Pâwave analysis, the median of our stress drop estimates is about a factor of 10 higher than the median stress drop of shallow earthquakes with the same magnitude estimated by Allmann and Shearer (2009, https://doi.org/10.1029/2008JB005821). This suggests that, on average, the shear stress of deep faults in the mantle transition zone is an order of magnitude higher than the shear stress of faults in the crust. The wide range of stress drops implies coexistence of multiple physical mechanisms.Plain Language SummaryThe change of shear stress (i.e., stress drop) during an earthquake is thought to be larger for deeper earthquakes than shallow earthquakes because of higher overburden pressure. However, the observational evidence for stress drop dependence on depth is still inconclusive. We estimate stress drops of earthquakes deeper than 400Â km from recorded ground motion spectra. We find that the median stress drop of deep earthquakes is about one order of magnitude higher than the stress drop of shallow (<50Â km) earthquakes. This implies that the shear stress of deep faults is moderately higher than of faults in the crust. The wide range of our stress drop estimates suggests that various mechanisms producing deep earthquakes coexist.Key PointsEmpiricalGreenâs functions are applied to analyze stress drops of deepâfocus earthquakesOne standard deviation ranges are 3.5â369.8Â MPa for P waves and 8.2â328.9Â MPa for S wavesThe median stress drops suggest that fault shear stress is an order of magnitude higher in the mantle than in the crustPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154937/1/grl60493_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154937/2/grl60493.pd
Functional genomic effects of indels using Bayesian genome-phenome wide association studies in sorghum
High-throughput genomic and phenomic data have enhanced the ability to detect genotype-to-phenotype associations that can resolve broad pleiotropic effects of mutations on plant phenotypes. As the scale of genotyping and phenotyping has advanced, rigorous methodologies have been developed to accommodate larger datasets and maintain statistical precision. However, determining the functional effects of associated genes/loci is expensive and limited due to the complexity associated with cloning and subsequent characterization. Here, we utilized phenomic imputation of a multi-year, multi-environment dataset using PHENIX which imputes missing data using kinship and correlated traits, and we screened insertions and deletions (InDels) from the recently whole-genome sequenced Sorghum Association Panel for putative loss-of-function effects. Candidate loci from genome-wide association results were screened for potential loss of function using a Bayesian Genome-Phenome Wide Association Study (BGPWAS) model across both functionally characterized and uncharacterized loci. Our approach is designed to facilitate in silico validation of associations beyond traditional candidate gene and literature-search approaches and to facilitate the identification of putative variants for functional analysis and reduce the incidence of false-positive candidates in current functional validation methods. Using this Bayesian GPWAS model, we identified associations for previously characterized genes with known loss-of-function alleles, specific genes falling within known quantitative trait loci, and genes without any previous genome-wide associations while additionally detecting putative pleiotropic effects. In particular, we were able to identify the major tannin haplotypes at the Tan1 locus and effects of InDels on the protein folding. Depending on the haplotype present, heterodimer formation with Tan2 was significantly affected. We also identified major effect InDels in Dw2 and Ma1, where proteins were truncated due to frameshift mutations that resulted in early stop codons. These truncated proteins also lost most of their functional domains, suggesting that these indels likely result in loss of function. Here, we show that the Bayesian GPWAS model is able to identify loss-of-function alleles that can have significant effects upon protein structure and folding as well as multimer formation. Our approach to characterize loss-of-function mutations and their functional repercussions will facilitate precision genomics and breeding by identifying key targets for gene editing and trait integration
Caesia sabulosa (Hemerocallidaceae), a new species from the Greater Cape Region of South Africa
The new species Caesia sabulosa Boatwr. and J.C.Manning from deep sands along the West Coast of South Africa and sandy flats in the Cederberg and Bokkeveld Escarpment is described. It is distinguished by its extensively branched rhizome resulting in a robust, clump-forming habit, and unique âpalisadeâ root system of closely packed, hard, vertical roots; mostly larger flowers; erect fruiting pedicels; and details of the seed testa sculpturing
Notes on the genus Trachyandra (Asphodelaceae: Asphodeloideae) 1: A review of the T. thyrsoidea group (Section Trachyandra) including three new species from the Northern Cape
Three new species of the genus Trachyandra are described, T. hantamensis Boatwr. & J.C.Manning, T. kamiesbergensis Boatwr. & J.C.Manning and T. sanguinorhiza Boatwr. & J.C.Manning. These species form part of a group of morphologically similar species referred to here as the T. thyrsoidea group and are distinguished by their generally small stature, filiform leaves (except for T. tortilis), and simple or shortly branched racemes of patent flowers with maculate tepals. Many of the species in the group have roots that contain abundant anthraquinones, visible as a red substance below the outer skin of the roots, and which is soluble in alcohol, thus often staining herbarium papers purple. A synopsis of the eight species that comprise the T. thyrsoidea group is presented, with maps of each species and illustrations of those described as new
A TAXONOMIC REVISION OF THE OTHONNA BULBOSA GROUP (ASTERACEAE: SENECIONEAE: OTHONNINAE)
Othonna L. (Asteraceae: Senecioneae: Othonninae) is a genus of some 120 species concentrated in the Greater Cape Floristic
Region (GCFR) of South Africa, with a few species extending into southern Namibia, Angola, and Zimbabwe. The South African
species of Othonna were last revised more than a century ago, and many species, particularly from the southern African winter
rainfall region, remain poorly understood. This study focused on the geophytic species comprising the O. bulbosa group,
distinguished by their tuberous rootstock and annual, leafy, aerial stems. A comprehensive taxonomic treatment is presented,
including descriptions, complete nomenclature and typification, illustrations, and geographical distribution. Twenty-five species
are recognized, of which four are newly described (O. lilacina Magoswana & J. C. Manning, O. nigromontana Magoswana & J. C.
Manning, O. revoluta Magoswana & J. C. Manning, and O. sinuata Magoswana & J. C. Manning), and 18 names are reduced to
synonymy. The species differ in habit, shape and incision of foliage, capitulum type (radiate vs. disciform), number of involucral
bracts, pappus length, and cypselae (myxogenic vs. nonmyxogenic). We place the species into four morphologically diagnosable
series (series Heterophyllae Magoswana & J. C. Manning, series Disciformes Magoswana & J. C. Manning, series Perfoliatae
Magoswana & J. C. Manning, and series Undulosae Magoswana & J. C. Manning) based on habit and capitulum type
Sorghum Association Panel whole-genome sequencing establishes cornerstone resource for dissecting genomic diversity
Association mapping panels represent foundational resources for understanding the genetic basis of phenotypic diversity and serve to advance plant breeding by exploring genetic variation across diverse accessions. We report the whole-genome sequencing (WGS) of 400 sorghum (Sorghum bicolor (L.) Moench) accessions from the Sorghum Association Panel (SAP) at an average coverage of 38Ă (25â72Ă), enabling the development of a high-density genomic marker set of 43 983 694 variants including single-nucleotide polymorphisms (approximately 38 million), insertions/deletions (indels) (approximately 5 million), and copy number variants (CNVs) (approximately 170 000). We observe slightly more deletions among indels and a much higher prevalence of deletions among CNVs compared to insertions. This new marker set enabled the identification of several novel putative genomic associations for plant height and tannin content, which were not identified when using previous lower-density marker sets. WGS identified and scored variants in 5-kb bins where available genotyping-by-sequencing (GBS) data captured no variants, with half of all bins in the genome falling into this category. The predictive ability of genomic best unbiased linear predictor (GBLUP) models was increased by an average of 30% by using WGS markers rather than GBS markers. We identified 18 selection peaks across subpopulations that formed due to evolutionary divergence during domestication, and we found six Fst peaks resulting from comparisons between converted lines and breeding lines within the SAP that were distinct from the peaks associated with historic selection. This population has served and continues to serve as a significant public resource for sorghum research and demonstrates the value of improving upon existing genomic resources
Exploitation of high-sampling Hi-net data to study seismic energy scaling: The aftershocks of the 2000 Western Tottori, Japan, earthquake
Detailed Investigation of the Foreshock Sequence of the 2010 Mw7.2 El MayorâCucapah Earthquake
Foreshocks can provide valuable information about possible nucleation process of a mainshock. However, their physical mechanisms are still under debate. In this study, we present a comprehensive analysis of the earthquake sequence preceding the 2010 Mw7.2 El MayorâCucapah mainshock, including waveform detection of missing smaller events, relative relocation, and source parameter analysis. Based on a template matching method, we find a tenfold increase in the number of earthquakes than reported in the Southern California Seismic Network catalog. The entire sequence exhibits nearly continuous episodes of foreshocks that can be loosely separated into two active clusters. Relocated foreshocks show several seismicity streaks at depth, with a consistently active cluster at depths between 14 and 16Â km where the mainshock was nucleated. Stress drop measurements from a spectral ratio approach based on empirical Greenâs functions show a range between 3.8 and 41.7Â MPa with a median of 13.0Â MPa and no clear temporal variations. The relocation results, together with the source patches estimated from earthquake corner frequencies, revealed a migration front toward the mainshock hypocenter within last 8Â hr and a chain of active burst immediately 6Â min prior to the mainshock. Our results support combined effects of aseismic slip and cascading failure on the evolution of foreshocks.Plain Language SummaryThe 2010 Mw7.2 El MayorâCucapah (EMC) earthquake was preceded by a prominent sequence of foreshocks starting ~21Â days before the mainshock. Several methods based on the similarities of waveforms are applied to obtain spatiotemporal evolution of foreshocks. Ten times more events are found from a template matching method when compared to the SCSN catalog. The refined relative locations reveal two main active clusters in time, as well as two spatial patches with a shallower one to the north of the mainshock epicenter. The depth distribution indicates several linear lines of seismicity, with a consistently active cluster at depths of 14â16Â km where mainshock started. An active cluster of foreshocks occurred in the last 6Â min. They likely altered the stress state near the hypocenter and ultimately triggered the mainshock. Our analysis indicates that both aseismic slip and cascade triggering processes occurred and contributed to the eventual triggering of the EMC mainshock.Key PointsA waveform matching technique leads to tenfold increase in the number of foreshocks when compared with the SCSN catalogWe resolve the corner frequency of 20 foreshocks using the detected events as empirical Greenâs functionsThe relocated catalog and estimated source patches reveal effects of both aseismic slip and cascading stress transferPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155988/1/jgrb54188.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155988/2/jgrb54188_am.pd
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