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Добірка наукової літератури з теми "LENGTH VARIATION"

Автор: Grafiati

Опубліковано: 11 вересня 2023

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Статті в журналах з теми "LENGTH VARIATION"

Suda, Takeshi, Asao Fujiyama, Mitsuhiro Takimoto, Masato Igarashi, Takashi Kuroiwa, Nobuo Waguri, Hirokazu Kawai, Yusaku Mita, and Yutaka Aoyagi. "Interchromosomal Telomere Length Variation." Biochemical and Biophysical Research Communications 291, no. 2 (February 2002): 210–14. http://dx.doi.org/10.1006/bbrc.2002.6425.

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Yoshida, Shigeo, and Yozo Hamano. "Geomagnetic decadal variations caused by length-of-day variation." Physics of the Earth and Planetary Interiors 91, no. 1-3 (September 1995): 117–29. http://dx.doi.org/10.1016/0031-9201(95)03038-x.

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Ono, Chikako, Terunao Ashida, Takao Sugiyama, Jun Fujii, and Kan Takayanagi. "Variation in Parasystolic Cycle Length." International Heart Journal 47, no. 1 (2006): 153–58. http://dx.doi.org/10.1536/ihj.47.153.

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Bond, Sharon. "GESTATIONAL LENGTH DEMONSTRATES NATURAL VARIATION." Journal of Midwifery & Women's Health 58, no. 6 (November 2013): 708–9. http://dx.doi.org/10.1111/jmwh.12143_1.

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Ridyard, Edward. "EXTRAOCULAR MUSCLES: VARIATION IN THEIR ANATOMY, LENGTH AND CROSS-SECTIONAL DIAMETER." International Journal of Anatomy and Research 3, no. 3 (August 2, 2015): 1198–206. http://dx.doi.org/10.16965/ijar.2015.164.

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Ziming Wang, Ziming Wang, Kang Su Kang Su, Bo Feng Bo Feng, Tianhua Zhang Tianhua Zhang, Weiqing Huang Weiqing Huang, Weicheng Cai Weicheng Cai, Wei Xiao Wei Xiao, Hongfei Liu Hongfei Liu, and Jianjun Liu Jianjun Liu. "Coupling length variation and multi-wavelength demultiplexing in photonic crystal waveguides." Chinese Optics Letters 16, no. 1 (2018): 011301. http://dx.doi.org/10.3788/col201816.011301.

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Lins, Carla Cabral dos Santos Accioly, Adelmar Afonso de Amorim Júnior, Bruna Paloma de Oliveira, Elma Mariana Verçosa de Melo Silva, and Raphaela Christianne Maia Soares Torres. "Variation of Length of Styloid Process." International Journal of Morphology 28, no. 4 (December 2010): 1277–80. http://dx.doi.org/10.4067/s0717-95022010000400046.

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Gagné, Olivier Charles, and Frank Christopher Hawthorne. "Bond-length distributions for ions bonded to oxygen: results for the transition metals and quantification of the factors underlying bond-length variation in inorganic solids." IUCrJ 7, no. 4 (June 9, 2020): 581–629. http://dx.doi.org/10.1107/s2052252520005928.

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Bond-length distributions are examined for 63 transition metal ions bonded to O2− in 147 configurations, for 7522 coordination polyhedra and 41 488 bond distances, providing baseline statistical knowledge of bond lengths for transition metals bonded to O2−. A priori bond valences are calculated for 140 crystal structures containing 266 coordination polyhedra for 85 transition metal ion configurations with anomalous bond-length distributions. Two new indices, Δtopol and Δcryst, are proposed to quantify bond-length variation arising from bond-topological and crystallographic effects in extended solids. Bond-topological mechanisms of bond-length variation are (1) non-local bond-topological asymmetry and (2) multiple-bond formation; crystallographic mechanisms are (3) electronic effects (with an inherent focus on coupled electronic vibrational degeneracy in this work) and (4) crystal-structure effects. The indices Δtopol and Δcryst allow one to determine the primary cause(s) of bond-length variation for individual coordination polyhedra and ion configurations, quantify the distorting power of cations via electronic effects (by subtracting the bond-topological contribution to bond-length variation), set expectation limits regarding the extent to which functional properties linked to bond-length variation may be optimized in a given crystal structure (and inform how optimization may be achieved) and more. These indices further provide an equal footing for comparing bond-length variation and the distorting power of ions across ligand types, including resolution for heteroligand polyhedra. The observation of multiple bonds is found to be primarily driven by the bond-topological requirements of crystal structures in solids. However, sometimes multiple bonds are observed to form as a result of electronic effects (e.g. the pseudo Jahn–Teller effect, PJTE); resolution of the origins of multiple-bond formation follows calculation of the Δtopol and Δcryst indices on a structure-by-structure basis. Non-local bond-topological asymmetry is the most common cause of bond-length variation in transition metal oxides and oxysalts, followed closely by the PJTE. Non-local bond-topological asymmetry is further suggested to be the most widespread cause of bond-length variation in the solid state, with no a priori limitations with regard to ion identity. Overall, bond-length variations resulting from the PJTE are slightly larger than those resulting from non-local bond-topological asymmetry, comparable with those resulting from the strong JTE, and less than those induced by π-bond formation. From a comparison of a priori and observed bond valences for ∼150 coordination polyhedra in which the strong JTE or the PJTE is the main reason underlying bond-length variation, the JTE is found not to have a cooperative relation with the bond-topological requirements of crystal structures. The magnitude of bond-length variation caused by the PJTE decreases in the following order for octahedrally coordinated d 0 transition metal oxyanions: Os8+ > Mo6+ > W6+ >> V5+ > Nb5+ > Ti4+ > Ta5+ > Hf4+ > Zr4+ > Re7+ >> Y3+ > Sc3+. Such ranking varies by coordination number; for [4] it is Re7+ > Ti4+ > V5+ > W6+ > Mo6+ > Cr6+ > Os8+ >> Mn7+; for [5] it is Os8+ > Re7+ > Mo6+ > Ti4+ > W6+ > V5+ > Nb5+. It is concluded that non-octahedral coordinations of d 0 ion configurations are likely to occur with bond-length variations that are similar in magnitude to their octahedral counterparts. However, smaller bond-length variations are expected from the PJTE for non-d 0 transition metal oxyanions.

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Brown, D. J., and B. J. Crook. "Environmental responsiveness of fibre diameter in grazing fine wool Merino sheep." Australian Journal of Agricultural Research 56, no. 7 (2005): 673. http://dx.doi.org/10.1071/ar04182.

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Fibre diameter, fibre length, and the ratio of fibre length growth to mean fibre diameter (L/D), fibre diameter profile characteristics, and staple strength were examined in 16 fine wool Merino wethers in a 12-month field experiment. Variations in fibre diameter, fibre length, and L/D were shown to be associated with fibre diameter profile characteristics and staple strength. At constant fibre diameter, L/D was significantly positively related to variation in fibre diameter along the staple. A positive correlation between seasonal variation in L/D and variation in diameter between fibres was also observed. Staple length was significantly positively correlated with along-staple variation in fibre diameter and negatively correlated with variation in fibre diameter among fibres. Among-fibre variation in fibre diameter was not significantly correlated with along-staple variation in fibre diameter. Seasonal variation in fibre length growth, fibre diameter, and the ratio of length to diameter throughout the year was associated with increased variation in fibre diameter along the fibre diameter profile and reduced staple strength in grazing sheep. Seasonal variation in fibre diameter was mostly related to mean fibre diameter, L/D, and seasonal variation in fibre length growth rate. Changes in fibre diameter throughout the year were also related to seasonal changes in body weight, fat depth, and skin thickness.

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Honjo, K., I. Furukawa, and M. H. Sahri. "Radial Variation of Fiber Length Increment in ACACIA MANGIUM." IAWA Journal 26, no. 3 (July 15, 2005): 339–52. http://dx.doi.org/10.1163/22941932-02603005.

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The radial variation of fiber length increment (due to intrusive growth) and its relation with internal and external (climatic) factors were investigated for Acacia mangium trees collected in Indonesia and Malaysia. Wood fiber length and fiber length increment were approximated with respect to the distance from the pith (x) by a logarithmic function and vessel element length by a linear function. The results were y = 0.14 . In(x) + 0.48, y = 0.0005 . x + 0.20, and y = 0.13 . ln(x) + 0.31, respectively. The radial variation of fiber length was related to the growth rate rather than the age of the cambium. The results of the cross-correlation function between wood fiber length increment and climatic factors showed that fiber lengths responded to changes in precipitation with a time lag of between zero to four months.

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Більше джерел

Дисертації з теми "LENGTH VARIATION"

Bell, S. R. "Mitochondrial DNA length variation in the mussel Mytilus." Thesis, Swansea University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636073.

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Three types of mitochondrial DNA length variation in Mytilus were examined. For the purposes of this study, the three variations were termed "macro-length-variation", "micro-length-variation" and "trossulus-length variation". Macro-length-variation was observed at a frequency of 25% at the hybrid M.galloprovincialis/M. edulis population at Mevagissey on the south Cornish coast, southwest England, Mitochondrial DNA (mtDNA) was extracted and digested with a diagnostic enzyme, EcoRI. Positive results with F-genome specific PCR primers and probes indicate that the macro-length-variant is F-genome mtDNA. The normal length for Mytilus mtDNA is approx. 17.4 kb. Macro-length-variants showed mtDNA of lengths between 21.2 and 31.2 kb with an incremental increase of approx. 2.08 kb. Micro-length-variation was observed during polyacrylamide gel electrophoresis of PCR product. Sequence directed bending of the DNA helix is proposed as the cause of the electrophoretic mobility variability. Trossulus-length-variation was studied in five M. trossulus mussels taken from the Gulf of Gdansk in the Baltic Sea. PCR primers flanking the putative control region revealed incremental length increase of approx. 200 bp. PCR product from a normal-length individual and a length-increased individual was cloned and sequenced revealing a single tandem repeat of 190 bp at the extreme 3' end of the putative control region. The repeat junction aligns with a flanking tRNA (tyr) gene. RFLP analysis at a separate PCR locus revealed close similarity between the M. trossulus samples and common M. edulis haplotypes, confirming the findings of previous studies.

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Sagit, Rauan. "Variation in length of proteins by repeats and disorder regions." Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-88553.

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Protein-coding genes evolve together with their genome and acquire changes, some of which affect the length of their protein products. This explains why equivalent proteins from different species can exhibit length differences. Variation in length of proteins during evolution arguably presents a large number of possibilities for improvement and innovation of protein structure and function. In order to contribute to an increased understanding of this process, we have studied variation caused by tandem domain duplications and insertions or deletions of intrinsically disordered residues. The study of two proteins, Nebulin and Filamin, together with a broader study of long repeat proteins (>10 domain repeats), began by confirming that tandem domains evolve by internal duplications. Next, we show that vertebrate Nebulins evolved by duplications of a seven-domain unit, yet the most recent duplications utilized different gene parts as duplication units. However, Filamin exhibits a checkered duplication pattern, indicating that duplications were followed by similarity erosions that were hindered at particular domains due to the presence of equivalent binding motifs. For long repeat proteins, we found that human segmental duplications are over-represented in long repeat genes. Additionally, domains that have formed long repeats achieved this primarily by duplications of two or more domains at a time. The study of homologous protein pairs from the well-characterized eukaryotes nematode, fruit fly and several fungi, demonstrated a link between variation in length and variation in the number of intrinsically disordered residues. Next, insertions and deletions (indels) estimated from HMM-HMM pairwise alignments showed that disordered residues are clearly more frequent among indel than non-indel residues. Additionally, a study of raw length differences showed that more than half of the variation in fungi proteins is composed of disordered residues. Finally, a model of indels and their immediate surroundings suggested that disordered indels occur in already disordered regions rather than in ordered regions.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 4: Manuscript.

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李玉嫻 and Yuk-han Li. "Telomere length variation and lineage chimerism in bone marrow transplantation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227594.

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Mateos, Mariana, and Therese Markow. "Ribosomal intergenic spacer (IGS) length variation across the Drosophilinae (Diptera: Drosophilidae)." BioMed Central, 2005. http://hdl.handle.net/10150/610372.

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BACKGROUND:The intergenic spacer of the ribosomal genes in eukaryotes (IGS) contains duplications of the core transcription promoter. The number of these duplicated promoters, as measured by the IGS length, appears to be correlated with growth rate and development time in several distantly related taxa. In the present study, we examined IGS length variation across a number of species of Drosophila to determine the amount of variation in this trait across different evolutionary time scales. Furthermore, we compared the usefulness of two methods commonly used to determine IGS length: Southern Blot Hybridization (SB) and Polymerase Chain Reaction (PCR).RESULTS:Our results show broad variation in IGS length across the genus Drosophila, but closely related species had similar IGS lengths. Our results also suggest that PCR tends to underestimate the true IGS size when the size is greater than 5 kb, and that this degree of underestimation is greater as the IGS size increases.CONCLUSION:Broad variation in IGS length occurs across large evolutionary divergences in the subfamily Drosophilinae. Although average IGS length has been shown to evolve rapidly under artificial selection, closely related taxa generally have similar average IGS lengths. Our comparison of methods suggests that without previous knowledge of the DNA sequence of the IGS and flanking regions, both methods be used to accurately measure IGS length.

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Quadri, Asima. "Assessment of genetic diversity in Asarum canadense L. using amplified fragment length polymorphism (AFLP)." Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1371851.

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Forest fragmentation poses a serious danger to population diversity in plants and animals by increasing species isolation, thus reducing the population size and genetic diversity. However, little information is available concerning how fragmentation impacts plant diversity. AFLP fingerprinting was used to assess genetic diversity within and between populations of Asarum canadense L. (Canadian Wild Ginger) across 11 different populations in East-Central Indiana. AFLP fingerprints using two primer pairs generated 51 distinct bands with an average of 25.5 bands per primer. Forty-eight low molecular weight distinct polymorphic bands were observed (50-200 bp range). The percentage of polymorphism was low (0-25%) indicating low levels of genetic diversity within each population studied. NTSYSpc Numerical Taxonomy Analysis Software generated aphenogram that revealed high levels of homologies within populations (75-100%), with individuals from the same population typically clustered. The genetic diversity between populations ranged from 10-50%. The populations from Jay, Randolph and Henry Counties clustered together exhibiting -54% homology, while populations from Mien, Madison, and Huntington counties shared approximately 64% homology. The populations from Adams, Blackford, Delaware, and Grant counties shared approximately 66% homology. However, within this last group Blackford and Delaware counties shared 90% homology. There were no apparent effects of the size of the forest fragments on the observed diversity measures. A possible relationship between genetic diversity and spatial distance was observed between populations moving from east to west. Possible reasons for this observation may be due to forest types, age of forests, climatic factors, soil types, and/or anthropogenic activities. Overall, the low level of average diversity within the populations strongly suggests that the individuals inhabiting isolated forests primarily propagate by asexual means.Ball State UniversityMuncie, IN 47306
Department of Biology

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Achouri, Ali. "Cartes de contrôle pour le coefficient de variation." Nantes, 2014. http://archive.bu.univ-nantes.fr/pollux/show.action?id=7658d471-1a91-4022-9493-9f85b2a06a86.

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La Maîtrise Statistique des Procédés (MSP) est une méthode de suivi de la production basée sur les statistiques. Elle se base essentiellement sur les cartes de contrôle. Une hypothèse indispensable pour le développement des cartes de contrôle est que les paramètres μ0 et 0 du procédé sous-contrôle soient supposés constants. Mais, dans la pratique, il existe de nombreux procédés pour lesquels ces paramètres peuvent être variables. Dans cette optique, le recours au coefficient de variation est une alternative intéressante. Dans cette thèse, nous avons essayé de systématiquement proposer de nouvelles cartes de contrôle pour le coefficient de variation qui n’ont pas encore été traitées jusqu’à présent dans la littérature. Des cartes de contrôle avec règles supplémentaires, des cartes VSI, VSS sont proposées pour le coefficient de variation lorsque les paramètres sont connus. De plus, une carte de type Shewhart pour le coefficient de variation avec paramètres estimés est aussi proposée. Les performances de chacune des cartes ont été évaluées et les paramètres optimaux ont été systématiquement calculés. Une validation empirique des résultats a été élaborée dans des processus industriels existants
The Statistical Process Control (SPC) is an effective method based on statistics and used to monitor production. Control charts are the most important and primary tools of SPC. An indispensable assumption for the development of control charts is that the process parameters μ0 and 0 are assumed constant. In practice, the process parameters are often variables and the use of the coefficient of variation seems to be an interesting alternative. In this thesis, we will investigate the properties (in terms of the Run Length) of some control charts for the coefficient of variation in the case of known parameters, which have not been researched till now, such as Run Rules Chart, VSI Chart and VSS Chart. In addition, a Shewhart control chart for the coefficient of variation with estimated parameters is proposed. The performance of each control chart has been evaluated and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes

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Malan, Roxanne. "Syllabic tone variation by Sepedi speakers with dysarthia." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/60384.

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Background: Speech production in Bantu languages places great demands on neuromotor control, because unique speech motor behaviours such as syllabic tone variation and the aspiration of speech sounds require an additional level of vocal fold control compared to speech production in Germanic languages. As these motor behaviours play an important role in differentiating the meaning of words (Van der Merwe & Le Roux, 2014a), neuromotor speech disorders such as dysarthria may have a greater impact on communication in Bantu languages than in Germanic languages. The focus of this study was on syllabic tone variation in Bantu language speakers with dysarthria compared to typical speakers. Sepedi was the Bantu language investigated. Syllabic tone variation refers to pitch level changes for every syllable of words in a tone language (Zerbian & Barnard, 2008a) and requires manipulation of vocal fold length and mass over and above the voicing or devoicing of sounds within words. These pitch changes convey the lexical and grammatical meaning of words and may differentiate between the meanings of two orthographically identical words (Zerbian & Barnard, 2008a). Studies on lexical tone variation in speakers with dysarthria to date have focused mostly on the tone languages of Asia and Scandinavia (Kadyamusuma, De Blesser, & Mayer, 2011). No studies of tone variation in Bantu language speakers with dysarthria were found. Furthermore, past research only regarded tone variation in monosyllabic words, with no reference to how tone would be affected across bisyllabic words and within each of the two syllables of these words. No inquiries were made into the tone variation ability of speakers with dysarthria when producing short utterances compared to longer utterances and mostly speakers with congenital dysarthria were used as research participants. These shortcomings needed to be addressed to gain a more holistic and accurate view of the extent to which tone variation is a challenge for Bantu language speakers with dysarthria. Aims: The first aim of the study was to determine whether a difference exists between typical Sepedi speakers and Sepedi speakers with dysarthria, in their ability to vary tone across CVCV words with a HL tone pattern. The second aim of the study was to determine whether a difference in tone variation exists between short and longer utterances in typical Sepedi speakers and Sepedi speakers with dysarthria. Method: A quasi-experimental, between-group comparison was used in the study. Speech samples were obtained from a control group of five typical Sepedi speakers and from an experimental group of four Sepedi speakers with dysarthria. These speech samples consisted of 20 consonant-vowel-consonant-vowel (CVCV) words with high-low (HL) tone variation produced in three- and also in six- /seven-syllable utterances (resulting in a total of 40 words). The speech samples were analysed acoustically using Praat software. To achieve the first aim, the following acoustic measures were obtained from the 40 words produced by participants: (1) Mean fundamental frequency (F0) of syllable 1 (S1) and syllable 2 (S2), (2) Change in F0 across words from the highest F0 point of S1 to the lowest F0 point of S2, (3) Intrasyllabic change in F0 within S1 and S2. To achieve the second aim of the study, the change in F0 across words in short utterances was compared to the change in F0 across words in longer utterances for the typical speakers and speakers with dysarthria. Results: Wilcoxon rank tests were used for statistical analyses. Descriptive statistics were performed and median values were used to achieve research aims. All of the control participants and participants with dysarthria produced S1 with a higher mean F0 than S2, as was appropriate for the HL tone pattern ascribed to the target words. For most of the individuals from both groups, the mean F0 of S1 was significantly higher than the mean F0 of S2. However, one participant from each group produced an insignificant difference between the mean F0 values of the two syllables. The control group produced slightly greater median F0 changes across the words and within S1 than the dysarthria group, but the differences between the speaker groups for the change in F0 across words and the change in F0 within S1 were insignificant. In contrast to this, the control group produced a significantly smaller median change in F0 within S2 than the dysarthria group. Individual speakers from both groups produced unique patterns of F0 changes for all aspects of tone variation (change in F0 across words and changes in F0 within S1 and S2). Both speaker groups produced a significantly greater median change in F0 across words in short utterances compared to long utterances. The difference in the change in F0 across words between short and long utterances was significantly greater for the control group than for the dysarthria group. Conclusions: The speakers with dysarthria in the study maintained the ability to vary tone across bisyllabic words with an HL tone pattern. The dysarthria group only differed significantly from the control group with regard to the extent of tone reduction in the second syllable. This finding may point to possible difficulties in the required graded relaxation of the vocal folds. Individual differences in F0 changes were found for both typical speakers and speakers with dysarthria, indicating that unique tone variation patterns may normally exist for all speakers. For both control and dysarthria groups, greater tone variation was observed in short compared to longer utterances. The role of increased utterance length in decreased F0 variation was greater for the typical speakers than for the individuals with dysarthria.
Dissertation (M Communication Pathology)--University of Pretoria, 2016.
Speech-Language Pathology and Audiology
M Communication Pathology
Unrestricted

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Niklison, Alina Maria. "INFLUENCE OF EMBRYONIC METABOLIC RATE AND INCUBATION TEMPERATURE ON INCUBATION LENGTH VARIATION IN NEOTROPICAL PASSERINES." The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-12212007-143823/.

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Variation in embryonic developmental periods influences fitness, but causes of interspecific variation are poorly understood. Allometry, for example, does not explain variation in incubation periods among neotropical passerines. Incubation temperature can explain some variation in developmental periods, but substantial variation remains unexplained. Here we examine two previously untested alternatives. Adult metabolic rates differ among species and similar differences among embryos may explain some variation in embryonic development rates; higher metabolism may allow faster cellular proliferation. Alternatively, metabolic rates are temperature dependent, and metabolic rates might respond differentially to temperature among species and compensate for differing incubation temperatures. These alternatives are untested across any taxa. Therefore, we examined them in tropical Venezuela by measuring embryonic metabolism at four temperatures in 15 passerine species with incubation periods ranging from 12 to 27 days. Embryonic metabolic rates responses to temperature were different among species even at constant embryonic age. Furthermore, species with lower average daily incubation temperature are less sensitive to changes in temperature than species with higher average incubation temperatures. Differences in embryonic mass specific metabolic rate among species explained a significant amount of variation in incubation periods after correcting for incubation temperature. Thus, differences in the rate of living as manifested through metabolism can influence developmental trajectories and deserve greater attention.

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Chakraborty, Ranjay. "Diurnal variation of ocular biometrics under natural and defocused conditions." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/61093/1/Ranjay_Chakraborty_Thesis.pdf.

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It is well known that a broad range of ocular anatomical and physiological parameters undergo significant diurnal variation. However, the natural diurnal variations that occur in the length of the human eye (axial length) and their underlying causes have been less well studied. Improvements in optical methods for the measurement of ocular biometrics now allow more precise and comprehensive measurements of axial length to be performed than has previously been possible. Research from animal models also suggests a link between diurnal axial length variations and longer term myopic eye growth, and that retinal image defocus can disrupt these diurnal rhythms in axial length. This research programme has examined the diurnal variations in axial length in young normal eyes, the contributing components and the influence of optical stimuli on these changes. In the first experiment, the normal pattern and consistency of the diurnal variations in axial length were examined at 10 different times (5 measurements each day, at ~ 3-hour intervals from ~ 9 am to ~ 9 pm) over 2 consecutive days on 30 young adult subjects (15 myopes, 15 emmetropes). Additionally, variations in a range of other ocular biometric measurements such as choroidal thickness, intraocular pressure, and other ocular biometrics were also explored as potential factors that may be associated with the observed variations in axial length. To investigate the potential influence of refractive error on diurnal axial length variations, the differences in the magnitude and pattern of diurnal variations in axial length between the myopic and emmetropic subjects were examined. Axial length underwent significant diurnal variation that was consistently observed over the 2 consecutive days of measurements, with the longest axial length typically occurring during the day, and the shortest at night. Significant diurnal variations were also observed in choroidal thickness, IOP and other ocular biometrics (such as central corneal thickness, anterior chamber depth and vitreous chamber depth) of the eye. Diurnal variations in vitreous chamber depth, IOP (positive associations) and choroidal thickness (negative association) were all significantly correlated with the diurnal changes in axial length. Choroidal thickness was found to fluctuate approximately in antiphase to the axial length changes, with the average timing of the longest axial length coinciding with the thinnest choroid and vice versa. There were no significant differences in the ocular diurnal variations associated with refractive error. Given that the diurnal changes in axial length could be associated with the changes in the eye’s optical quality, whether the optical quality of the eye also undergoes diurnal variation in the same cohort of young adult myopes and emmetropes over 2 consecutive days was also examined. Significant diurnal variations were observed only in the best sphere refraction (power vector M) and in the spherical aberration of the eye over two consecutive days of testing. The changes in the eyes lower and higher order ocular optics were not significantly associated with the diurnal variations in axial length and the other measured ocular biometric parameters. No significant differences were observed in the magnitude and timing of diurnal variations in lower-order and higher-order optics associated with refractive error. Since the small natural fluctuations in the eye’s optical quality did not appear to be sufficient to influence the natural diurnal fluctuations in ocular biometric parameters, in the next experiment, the influence of monocular myopic defocus (+1.50 DS) upon the normal diurnal variations in axial length and choroidal thickness of young adult emmetropic human subjects (n=13) imposed over a 12 hour period was examined. A series of axial length and choroidal thickness measurements (collected at ~3 hourly intervals, with the first measurement at ~9 am and the final measurement at ~9 pm) were obtained over three consecutive days. The natural diurnal rhythms (Day 1, no defocus), diurnal rhythms with monocular myopic defocus (Day 2, +1.50 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, no defocus) were examined. Significant diurnal variations over the course of the day were observed in both axial length and choroidal thickness on each of the three measurement days. The introduction of monocular myopic defocus led to significant reductions in the mean amplitude of diurnal change, and phase shifts in the peak timing of the diurnal rhythms in axial length and choroidal thickness. These defocus induced changes were found to be transient in nature and returned to normal the day following removal of the defocus. To further investigate the influence of optical stimuli on human diurnal rhythms, in the final experiment, the influence of monocular hyperopic defocus on the normal diurnal rhythms in axial length and choroidal thickness was examined in young adult emmetropic subjects (n=15). Similar to the previous experiment, the natural diurnal rhythms (Day 1, no defocus), diurnal rhythms with monocular hyperopic defocus (Day 2, -2.00 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, no defocus) were examined over three consecutive days. Both axial length and choroidal thickness underwent significant diurnal variations on each of the three days. The introduction of monocular hyperopic defocus resulted in a significant increase in the amplitude of diurnal change, but no change in the peak timing of diurnal rhythms in both parameters. The ocular changes associated with hyperopic defocus returned to normal, the day following removal of the defocus. This research has shown that axial length undergoes significant diurnal variation in young adult human eyes, and has shown that the natural diurnal variations in choroidal thickness and IOP are significantly associated, and may underlie these diurnal fluctuations in axial length. This work also demonstrated for the first time that exposing young human eyes to monocular myopic and hyperopic defocus leads to a significant disruption in the normal diurnal rhythms of axial length and choroidal thickness. These changes in axial length with defocus may reflect underlying mechanisms in the human eye that are involved in the regulation of longer term eye growth.

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Amdouni, Asma. "Surveillance statistique du coefficient de variation dans un contexte de petites séries." Nantes, 2015. http://archive.bu.univ-nantes.fr/pollux/show.action?id=dcf36868-32b2-41d6-916b-f9533ee12902.

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La maîtrise statistique des procédés (MSP) est une méthode de contrôle de la qualité basée sur les statistiques. La surveillance du coefficient de variation est une approche efficace à la MSP lorsque la moyenne du processus µ et son écart type σ ne sont pas constants mais leur rapport est constant. Jusqu’à présent, les études portant sur la surveillance du coefficient de variation se sont limitées au cas d’une production avec un horizon infini. Cette thèse présente de nouvelles cartes de contrôle pour surveiller le coefficient de variation dans le contexte fini lorsque les paramètres sont connus : des cartes de contrôle séparées de type Shewhart, des cartes avec des règles supplémentaires et des cartes VSI et VSS. Les paramètres optimaux ont été systématiquement calculés et les performances de chacune de ces cartes ont été également évaluées en développant de nouvelles mesures statistique de performance appropriées dans un contexte de production à horizon fini. Une validation empirique des résultats a été élaborée pour des procédés industriels existants
Statistical Process Control (SPC) is a method of quality control based on statistics and used to monitor production. Monitoring the coefficient of variation is an effective approach to SPC when the process mean µ and standard deviation σ are not constant but their ratio is constant. Until now, research has not investigated the monitoring of the coefficient of variation for short production runs. Viewed under this perspective, in this thesis, we will propose new methods to monitor the coefficient of variation for a finite horizon production, we will investigate the properties (in terms of the Truncated Run Length) of some control charts for the coefficient of variation in a Short Run context in the case of known parameters, such as the one-sided Shewhart Chart, the Run Rules Chart, the VSI and VSS Charts. The performance of each control chart has been evaluated by developing statistical measures of performance appropriate in a Short Run context and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes

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Книги з теми "LENGTH VARIATION"

Bhattacherjee, Vasker. Variation in the restriction fragment length in the DNA of species of 'Aspergillus' and 'Penicillium'. Birmingham: University of Birmingham, 1989.

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1918-, Weinberg Irving, Flood Dennis J, and United States. National Aeronautics and Space Administration., eds. Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells. [Washington, DC: National Aeronautics and Space Administration, 1993.

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Jain, Raj K. Diffusion length variation in 0.5- and 3-MeV-proton-irradiated, heteroepitaxial indium phosphide solar cells. [Washington, DC: National Aeronautics and Space Administration, 1993.

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Chen, Erluo. Variation in hospital length of stay for acute myocardial infarction in Ontario, Canada, during fiscal 1990: A population-based analysis. North York, Ont: Institute for Clinical Evaluative Sciences in Ontario, 1993.

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E, Chen, Naylor C. D, and Institute for Clinical Evaluative Sciences in Ontario., eds. Variation in hospital length of stay for acute myocardial infarction in Ontario, Canada, during fiscal 1990: A population-based analysis. Ontario: Institute for Clinical Evaluative Sciences in Ontario, 1993.

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Henning, Grant. A study of the effects of variation of short-term memory load, reading response length, and processing hierarchy on TOEFL listening comprehension item performance. Princeton, NJ: Educational Testing Service, 1991.

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Coulas, Jess Alexander. Variation in leaf lifespan, relative growth rate, and underlying structural leaf traits in wetland plants originating along a latitudinal gradient of growing season length in Ontario. Sudbury, Ont: Laurentian University, School of Graduate Studies, 2005.

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National Center for Health Services Research and Health Care Technology Assessment (U.S.) and Dartmouth Medical School, eds. Small area variations in hospitalized case mix for DRGs in Maine, Massachusetts and Iowa. [Rockville, Md.?]: National Center for Health Services Research and Health Care Technology Assessment, Public Health Service, U.S. Dept. of Health and Human Services, 1985.

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Variational problems in topology: The geometry of length, area and volume. New York: Gordon and Breach Science Publishers, 1990.

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George C. Marshall Space Flight Center, ed. North Atlantic basin tropical cyclone activity in relation to temperature and decadal-length oscillation patterns. Huntsville], Ala: National Aeronautics and Space Administration, Marshall Space Flight Center, 2009.

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Частини книг з теми "LENGTH VARIATION"

Cedergren, Henrietta J. "Rhythm and length in phonological variation." In Studies in Romance Linguistics, 69. Amsterdam: John Benjamins Publishing Company, 1989. http://dx.doi.org/10.1075/cilt.60.05ced.

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Wetzels, W. Leo. "On the relation between quantity-sensitive stress and distinctive vowel length." In Romance Phonology and Variation, 219–34. Amsterdam: John Benjamins Publishing Company, 2002. http://dx.doi.org/10.1075/cilt.217.16wet.

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Rudnicka, Karolina. "Variation of sentence length across time and genre." In Studies in Corpus Linguistics, 219–40. Amsterdam: John Benjamins Publishing Company, 2018. http://dx.doi.org/10.1075/scl.85.10rud.

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Struz, Jiri, Lukas Hruzik, and Jiri Havlik. "Cardan Shaft Load and Its Variation with Length." In Atlantis Highlights in Engineering, 343–55. Dordrecht: Atlantis Press International BV, 2023. http://dx.doi.org/10.2991/978-94-6463-182-1_36.

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Klein, J., Y. Satta, and R. Gongora. "Evolution of Length Variation in the Primate Mhc DR Subregion." In Molecular Biology and Evolution of Blood Group and MHC Antigens in Primates, 372–85. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-59086-3_15.

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Salim, Asif, S. S. Shiju, and S. Sumitra. "Effectiveness of Representation and Length Variation of Shortest Paths in Graph Classification." In Lecture Notes in Computer Science, 509–16. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-69900-4_65.

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Hart, Barry T., Paul Freeman, and Ian D. McKelvie. "Whole-stream phosphorus release studies: variation in uptake length with initial phosphorus concentration." In Sediment/Water Interactions, 573–84. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2783-7_50.

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Dickey, J. O., S. L. Marcus, T. M. Eubanks, and R. Hide. "Climate studies via space geodesy: Relationships between ENSO and interannual length-of-day variation." In Interactions Between Global Climate Subsystems: The Legacy of Hann, 141–55. Washington, D. C.: American Geophysical Union, 1993. http://dx.doi.org/10.1029/gm075p0141.

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Prateek, Harsh, B. V. Subrahmanyam, Sanjoy Kumar Saha, M. M. Patil, and V. Ashok. "Effect of Sampling Length on Variation of SPL and Its Effects at Low Frequency." In Lecture Notes in Mechanical Engineering, 441–46. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-7055-9_74.

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Salgado-Robles, Francisco, and Angela George. "Chapter 1. Relationship between external factors and development of regional variation ( vosotros vs. ustedes ) by L2 learners of Spanish in Spain." In Study Abroad and the Second Language Acquisition of Sociolinguistic Variation in Spanish, 20–53. Amsterdam: John Benjamins Publishing Company, 2023. http://dx.doi.org/10.1075/ihll.37.01sal.

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This chapter focuses on the impact of three key programmatic features – program type, housing condition, and program length – on the development of a geographically variable feature, the second-person plural forms of address (i.e., vosotros/ustedes distinction) by second language learners of Spanish studying abroad in Madrid, Spain. Additionally, we compare the use of both vosotros and ustedes to a local Madrileño speaker baseline. To measure the use of vosotros and ustedes, the participants completed an oral discourse completion task. While the results of the study point to an increase in vosotros production among all participants, the students enrolled in a service-learning program, living with a host family, and participating in a long-term program significantly increased their use of vosotros.

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Тези доповідей конференцій з теми "LENGTH VARIATION"

Vendra, Satya K., and Malgorzata Chrzanowska-Jeske. "Carbon Nanotube Length Variation in Correlated CNFETs." In 2020 IEEE 20th International Conference on Nanotechnology (IEEE-NANO). IEEE, 2020. http://dx.doi.org/10.1109/nano47656.2020.9183538.

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Friedberg, Paul, Willy Cheung, and Costas J. Spanos. "Spatial modeling of micron-scale gate length variation." In SPIE 31st International Symposium on Advanced Lithography, edited by Iraj Emami and Kenneth W. Tobin, Jr. SPIE, 2006. http://dx.doi.org/10.1117/12.656521.

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Mahabub Hossain, Md, Wu Bin, and Seong Ho Kong. "Electromagnetically controlled convex micromirror for focal length variation." In 2015 IEEE Sensors. IEEE, 2015. http://dx.doi.org/10.1109/icsens.2015.7370267.

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Sparrold, Scott W. "Thick lens chromatic effective focal length variation versus bending." In International Optical Design Conference 2017, edited by Richard N. Pfisterer, John R. Rogers, Julius A. Muschaweck, and Peter P. Clark. SPIE, 2017. http://dx.doi.org/10.1117/12.2292745.

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Kulkarni, Upendra, Monish M. H. Gowda, and Hima Kiran Venna. "Effect of Tie Rod Length Variation on Bump Steer." In International Mobility Conference. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2016. http://dx.doi.org/10.4271/2016-28-0201.

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Sparrold, Scott W. "Thick Lens Chromatic Effective Focal Length Variation Versus Bending." In International Optical Design Conference. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/iodc.2017.im3a.4.

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Kinugasa, Tetsuya, Shoichi Miwa, Yannick Aoustin, and Christine Chevallereau. "GAIN PROPERTY FOR BIPED WALKING VIA LEG LENGTH VARIATION." In Proceedings of 10th International Conference (CLAWAR 2007). WORLD SCIENTIFIC, 2007. http://dx.doi.org/10.1142/9789812770189_0042.

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Shen, Nan, ZhiPing Yin, and WeiDong Chen. "A compensation method for baseline length variation in InISAR imaging." In 2009 2nd Asian-Pacific Conference on Synthetic Aperture Radar (APSAR). IEEE, 2009. http://dx.doi.org/10.1109/apsar.2009.5374250.

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Sanudin, Rahmat, Muhammad Suhaimi Sulong, Marlia Morsin, and Mohd Helmy Abd Wahab. "Simulation study on NMOS gate length variation using TCAD tool." In 2009 1st Asia Symposium on Quality Electronic Design (ASQED 2009). IEEE, 2009. http://dx.doi.org/10.1109/asqed.2009.5206255.

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Saini, S. S., Z. Dilli, F. G. Johnson, D. R. Stone, H. Shen, W. Zhou, and M. Dagenais. "Taper Length Variation in Passive Active Resonant Coupler (PARC) Platform." In Integrated Photonics Research. Washington, D.C.: OSA, 2000. http://dx.doi.org/10.1364/ipr.2000.ithg3.

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Звіти організацій з теми "LENGTH VARIATION"

Platz, Elizabeth A. Realizing the Translational Potential of Telomere Length Variation as a Tissue-Based Prognostic Marker for Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, October 2014. http://dx.doi.org/10.21236/ada613262.

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Kistler, Harold Corby, Talma Katan, and Dani Zamir. Molecular Karyotypes of Pathogeic Strains of Fusarium oxysporum. United States Department of Agriculture, June 1995. http://dx.doi.org/10.32747/1995.7604927.bard.

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Genetic diversity of pathogenic strains of the fungus Fusarium oxysporum was determied by analysis of electrophoretic karyotype, as well as by DNA variation detected by Restriction Fragment Length Polymorphisms (RFLPs) and Random Amplified Polymorphic DNAs (RAPDs). The electrophoretic karyotypes for 130 isolates of the fungus pathogenic to tomato, melon, and banana were analyzed. Electrophoretic karyotype variation, reflected in differences in apparent chromosome number and genome size, was observed even among isolates from the same host and sub specific category. Sub specific categories studied were forma specialis, vegetative compatibility group (VCG) and race. Chromosome number and genome size variation was less for isolates within the same VCG than for the collection of isolates as a whole. RFLP and RAPD analysis were performed on 62 isolates of F. oxysporum from tomato and melon. Polygenetic trees were constructed from genetic diversity data. The results support the hypothesis that isolates belonging to the same VCG originate from a single ancestor compared to other isolates. The results do not support the hypothesis that all isolates belonging to the same forma specialis originate from a common ancestor. These conclusions have profound implication for breeding resistance to diseases caused by particular formae speciales of F. oxysporum.

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Garganta, Santiago, María Florencia Pinto, and Joaquín Zentner. Extended School Day and Teenage Fertility in Dominican Republic. Inter-American Development Bank, October 2022. http://dx.doi.org/10.18235/0004496.

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This paper investigates the potential impact of extended school days in reducing teenage fertility. We study the Jornada Escolar Extendida program, which doubled the school-day length from 4 to 8 hours in the Dominican Republic, and exploit the geographic and time variation induced by its gradual implementation. We find evidence that a higher exposure to JEE in the municipality, measured as the percentage of secondary students covered by the program, reduces the incidence of teenage pregnancies, and that the effect is stronger after the program has reached at least half of secondary students in the municipality. The estimates are robust to various specifications and alternative checks. These results suggest that extended school-day policies can have spillover effects regarding teenagers fertility choices.

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Teitsma, Albert. L52091 Better Understanding of Mechanical Damage in Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2004. http://dx.doi.org/10.55274/r0011829.

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This report summarizes work done at the Battelle Memorial Institute, (Nestleroth, 2003) and the Southwest Research Institute (Chell, 2003) on "Better Understanding of Mechanical Damage in Pipelines" for DOT and GTI under the direction of the Gas Technology Institute. Battelle Memorial Institute concentrated on developing MFL technologies for detecting and characterizing mechanical damage defects. Combining axial and circumferential MFL, provides sensitivity to defects of all orientations, accurately determines the width and length of a defect, and more accurately predicts defect depths due to better compensation for geometry generated MFL amplitude changes. High-low magnetization field MFL detects and qualitatively characterizes mechanical defects and provides a quantitative measure of the depth of the initial dent from the reround halo if the pipe has rerounded. Absence of a reround halo would indicate a possibly innocuous defect. Good correlation was found between FEA stresses and strains and the measured NLH results. NLH characterizes mechanical damage qualitatively. Fractographic and metalograhpic analysis after burst tests were used along with engineering judgment and stress calculation to rank the severity of mechanical damage with respect to variation in length width and depth. An empirical formula is proposed for quickly calculating the relative severity of mechanical damage defects. All methods for characterizing mechanical damage, the formula, fractographic and metallographic, MFL, NLH, FEA, and engineering judgment correlated well with each other.

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Briggs, Nicholas E., Robert Bailey Bond, and Jerome F. Hajjar. Cyclic Behavior of Steel Headed Stud Anchors in Concrete-filled Steel Deck Diaphragms through Push-out Tests. Northeastern University. Department of Civil and Environmental Engineering., February 2023. http://dx.doi.org/10.17760/d20476962.

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Earthquake disasters in the United States account for $6.1 billion of economic losses each year, much of which is directly linked to infrastructure damage. These natural disasters are unpredictable and represent one of the most difficult design problems in regard to constructing resilient infrastructure. Structural floor and roof diaphragms act as the horizontal portion of the lateral force resisting system (LFRS), distributing the seismically derived inertial loads out from the heavy concrete slabs to the vertical LFRS. Composite concrete-filled steel deck floor and roof diaphragms are ubiquitously used in commercial construction worldwide due to the ease of construction and cost-effective use of structural material. This report presents a series of composite steel deck diaphragm Push-out tests at full scale that explore the effect that cyclic loading has on the strength of steel headed stud anchors. The effect that cyclic loading has on structural performance is explored across the variation of material and geometric parameters in the Push-out specimens, such as concrete density, steel headed stud anchor placement and grouping, steel deck orientation, and edge conditions. As compared to prior tests in the literature, the push-out tests conducted in this work have an extended specimen length that includes four rows of studs along the length rather than the typical two rows of studs, and an ability to impose cyclic loading. This provides novel insight into force flows in the specimens, failure mechanisms, and load distribution between studs and stud groups.

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Johnson. L51935 Limitations of Cellulosic-Coated Electrodes. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), October 2003. http://dx.doi.org/10.55274/r0010434.

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Cellulosic-coated electrodes (primarily AWS EXX10-type) are traditionally used for stovepipe welding of pipelines because they are well suited for deposition of one-sided welds and are capable of high deposition rates when welding downhill. Despite advances in mechanized welding technology and the development of low-hydrogen consumables suitable for pipeline girth welding, manual welding, using cellulosic-coated electrodes is still widely utilized for pipeline construction throughout the world. Several incidents involving significant hydrogen-assisted cracking in the weld metal of pipeline girth welds made using cellulosic-coated electrodes have been reported recently. Two of these cases required removal of many welds at an expense of over $4 million dollars, in spite of established procedures having been used. The objectives of this project were to identify the primary mechanisms contributing to transverse cracking of field welds and to provide recommendations regarding safe preheat/interpass temperatures that should be utilized when welding heavy-wall pipe and fittings using cellulosic-coated electrodes. Two cases of severe weld metal hydrogen-assisted cracking were investigated. In each case, the composition of the weld metal was substantially richer that would typically be expected for E8010-G electrodes. Subsequent investigation into factors influencing the composition of weld metal from cellulosic-coated electrodes revealed that arc length has a pronounced effect on carbon, manganese, and silicon recovery. The increase in composition observed with variation in arc length could not explain the extremely rich compositions observed in the cracked girth welds, however. Subsequent investigation demonstrated that it was possible to effectively double the manganese concentration and triple the silicon concentration when using cellulosic coated electrodes that have low coating moisture content.

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Blum, Abraham, and Henry T. Nguyen. Molecular Tagging of Drought Resistance in Wheat: Osmotic Adjustment and Plant Productivity. United States Department of Agriculture, November 2002. http://dx.doi.org/10.32747/2002.7580672.bard.

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Drought stress is a major limitation to bread wheat (Triticumaestivum L.) productivity and its yield stability in arid and semi-arid regions of world including parts of Israel and the U.S. Currently, breeding for sustained yields under drought stress is totally dependent on the use of yield and several key physiological attributes as selection indices. The attempt to identify the optimal genotype by evaluating the phenotype is undermining progress in such breeding programs. Osmotic adjustment (OA) is an effective drought resistance mechanism in many crop plants. Evidence exists that there is a genetic variation for OA in wheat and that high OA capacity supports wheat yields under drought stress. The major objective of this research was to identify molecular markers (RFLPs, restriction fragment length polymorphisms; and AFLPs, amplified fragment length polymorph isms) linked to OA as a major attribute of drought resistance in wheat and thus to facilitate marker-assisted selection for drought resistance. We identified high and low OA lines of wheat and from their cross developed recombinant inbred lines (RILs) used in the molecular tagging of OA in relation to drought resistance in terms of plant production under stress. The significant positive co-segregation of OA, plant water status and yield under stress in this RIL population provided strong support for the important role of OA as a drought resistance mechanism sustaining wheat production under drought stress. This evidence was obtained in addition to the initial study of parental materials for constructing this RIL population, which also gave evidence for a strong correlation between OA and grain yield under stress. This research therefore provides conclusive evidence on the important role of OA in sustaining wheat yield under drought stress. The measurement of OA is difficult and the selection for drought resistance by the phenotypic expression of OA is practically impossible. This research provided information on the genetic basis of OA in wheat in relations to yield under stress. It provided the basic information to indicate that molecular marker assisted selection for OA in wheat is possible. The RIL population has been created by a cross between two agronomic spring wheat lines and the high OA recombinants in this population presented very high OA values, not commonly observed in wheat. These recombinants are therefore an immediate valuable genetic recourse for breeding well-adapted drought resistant wheat in Texas and Israel. We feel that this work taken as a whole eliminate the few previous speculated . doubts about the practical role of OA as an important mechanism of drought resistance in economic crop plants. As such it should open the way, in terms of both concept and the use of marker assisted selection, for improving drought resistance in wheat by deploying high osmotic adjustment.

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Eshel, Amram, Jonathan P. Lynch, and Kathleen M. Brown. Physiological Regulation of Root System Architecture: The Role of Ethylene and Phosphorus. United States Department of Agriculture, December 2001. http://dx.doi.org/10.32747/2001.7585195.bard.

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Specific Objectives and Related Results: 1) Determine the effect of phosphorus availability on ethylene production by roots. Test the hypothesis that phosphorus availability regulates ethylene production Clear differences were found between the two plants that were studied. In beans ethylene production is affected by P nutrition, tissue type, and stage of development. There are genotypic differences in the rate of ethylene production by various root types and in the differential in ethylene production when P treatments are compared. The acceleration in ethylene production with P deficiency increases with time. These findings support the hypothesis that ethylene production may be enhanced by phosphorus deficiency, and that the degree of enhancement varies with genotype. In tomatoes the low-P level did not enhance significantly ethylene production by the roots. Wildtype cultivars and ethylene insensitive mutants behaved similarly in that respect. 2) Characterize the effects of phosphorus availability and ethylene on the architecture of whole root systems. Test the hypothesis that both ethylene and low phosphorus availability modify root architecture. In common bean, the basal roots give rise to a major fraction of the whole root system. Unlike other laterals these roots respond to gravitropic stimulation. Their growth angle determines the proportion of the root length in the shallow layers of the soil. A correlation between ethylene production and basal root angle was found in shallow rooted but not deep-rooted genotypes, indicating that acceleration of ethylene synthesis may account for the change in basal root angle in genotypes demonstrating a plastic response to P availability. Short-time gravitropic response of the tap roots of young bean seedlings was not affected by P level in the nutrient solution. Low phosphorus specifically increases root hair length and root hair density in Arabidopsis. We tested 7 different mutants in ethylene perception and response and in each case, the response to low P was lower than that of the wild-type. The extent of reduction in P response varied among the mutants, but every mutant retained some responsiveness to changes in P concentration. The increase in root hair density was due to the increase in the number of trichoblast cell files under low P and was not mediated by ethylene. Low P did not increase the number of root hairs forming from atrichoblasts. This is in contrast to ethylene treatment, which increased the number of root hairs partly by causing root hairs to form on atrichoblasts. 3) Assess the adaptive value of root architectural plasticity in response to phosphorus availability. A simulation study indicated that genetic variation for root architecture in common bean may be related to adaptation to diverse competitive environments. The fractal dimension of tomato root system was directly correlated with P level.

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Sherman, Amir, Rebecca Grumet, Ron Ophir, Nurit Katzir, and Yiqun Weng. Whole genome approach for genetic analysis in cucumber: Fruit size as a test case. United States Department of Agriculture, December 2013. http://dx.doi.org/10.32747/2013.7594399.bard.

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The Cucurbitaceae family includes a broad array of economically and nutritionally important crop species that are consumed as vegetables, staple starches and desserts. Fruit of these species, and types within species, exhibit extensive diversity as evidenced by variation in size, shape, color, flavor, and others. Fruit size and shape are critical quality determinants that delineate uses and market classes and are key traits under selection in breeding programs. However, the underlying genetic bases for variation in fruit size remain to be determined. A few species the Cucurbitaceae family were sequenced during the time of this project (cucumber was already sequenced when the project started watermelon and melon sequence became available during the project) but functional genomic tools are still missing. This research program had three major goals: 1. Develop whole genome cucumber and melon SNP arrays. 2. Develop and characterize cucumber populations segregating for fruit size. 3. Combine genomic tools, segregating populations, and phenotypic characterization to identify loci associated with fruit size. As suggested by the reviewers the work concentrated mostly in cucumber and not both in cucumber and melon. In order to develop a SNP (single nucleotide polymorphism) array for cucumber, available and newly generated sequence from two cucumber cultivars with extreme differences in shape and size, pickling GY14 and Chinese long 9930, were analyzed for variation (SNPs). A large set of high quality SNPs was discovered between the two parents of the RILs population (GY14 and 9930) and used to design a custom SNP array with 35000 SNPs using Agilent technology. The array was validated using 9930, Gy14 and F1 progeny of the two parents. Several mapping populations were developed for linkage mapping of quantitative trait loci (QTL) for fruit size These includes 145 F3 families and 150 recombinant inbred line (RILs F7 or F8 (Gy14 X 9930) and third population contained 450 F2 plants from a cross between Gy14 and a wild plant from India. The main population that was used in this study is the RILs population of Gy14 X 9930. Phenotypic and morphological analyses of 9930, Gy14, and their segregating F2 and RIL progeny indicated that several, likely independent, factors influence cucumber fruit size and shape, including factors that act both pre-anthesis and post-pollination. These include: amount, rate, duration, and plane of cell division pre- and post-anthesis and orientation of cell expansion. Analysis of F2 and RIL progeny indicated that factors influencing fruit length were largely determined pre-anthesis, while fruit diameter was more strongly influenced by environment and growth factors post-anthesis. These results suggest involvement of multiple genetically segregating factors expected to map independently onto the cucumber genome. Using the SNP array and the phenotypic data two major QTLs for fruit size of cucumber were mapped in very high accuracy (around 300 Kb) with large set of markers that should facilitate identification and cloning of major genes that contribute to fruit size in cucumber. In addition, a highly accurate haplotype map of all RILS was created to allow fine mapping of other traits segregating in this population. A detailed cucumber genetic map with 6000 markers was also established (currently the most detailed genetic map of cucumber). The integration of genetics physiology and genomic approaches in this project yielded new major infrastructure tools that can be used for understanding fruit size and many other traits of importance in cucumber. The SNP array and genetic population with an ultra-fine map can be used for future breeding efforts, high resolution mapping and cloning of traits of interest that segregate in this population. The genetic map that was developed can be used for other breeding efforts in other populations. The study of fruit development that was done during this project will be important in dissecting function of genes that that contribute to the fruit size QTLs. The SNP array can be used as tool for mapping different traits in cucumber. The development of the tools and knowledge will thus promote genetic improvement of cucumber and related cucurbits.

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