5,886 research outputs found
Understanding Early Withdrawals From Retirement Accounts
Examines early withdrawals from IRAs and 401(k)s by demographics, education, income, and reason, including job loss, poor health, and college costs. Suggests policies to expand plan participation, preserve retirement savings, and increase other savings
Sur les limites d'application du modèle de Stephens
Les conséquences de l'hypothèse de la conservation de j dans le modèle de Stephens sont analysées. Les conditions de l'applicabilité de cette hypothèse dans le cas des sous-couches isolées (l'extension est faite à N = 4 et N = 3) sont discutées et des explications en sont données. Dans les autres cas, un traitement exact des états propres du mouvement intrinsèque permet néanmoins l'extension du modèle de Stephens sans élargissement de la base de diagonalisation
Spectral studies of some hydroxy-derivatives of anthraquinones
The u.v., visible, and i.r. spectra of several hydroxy-anthraquinones are discussed and the bands are assigned. These bands are compared with those of anthracene and anthraquinone. The band at 207 nm. is assigned to a n-sigma* transition; the bands at 252, 272, and 326 nm. are assigned by measuring spectra in solvents of various polarities. The stability constant for the 12-dihydroxyanthraquinone-ethanol complex is obtained
Association Studies and Legume Synteny Reveal Haplotypes Determining Seed Size in Vigna unguiculata.
Highly specific seed market classes for cowpea and other grain legumes exist because grain is most commonly cooked and consumed whole. Size, shape, color, and texture are critical features of these market classes and breeders target development of cultivars for market acceptance. Resistance to biotic and abiotic stresses that are absent from elite breeding material are often introgressed through crosses to landraces or wild relatives. When crosses are made between parents with different grain quality characteristics, recovery of progeny with acceptable or enhanced grain quality is problematic. Thus genetic markers for grain quality traits can help in pyramiding genes needed for specific market classes. Allelic variation dictating the inheritance of seed size can be tagged and used to assist the selection of large seeded lines. In this work we applied 1,536-plex SNP genotyping and knowledge of legume synteny to characterize regions of the cowpea genome associated with seed size. These marker-trait associations will enable breeders to use marker-based selection approaches to increase the frequency of progeny with large seed. For 804 individuals derived from eight bi-parental populations, QTL analysis was used to identify markers linked to 10 trait determinants. In addition, the population structure of 171 samples from the USDA core collection was identified and incorporated into a genome-wide association study which supported more than half of the trait-associated regions important in the bi-parental populations. Seven of the total 10 QTLs were supported based on synteny to seed size associated regions identified in the related legume soybean. In addition to delivering markers linked to major trait determinants in the context of modern breeding, we provide an analysis of the diversity of the USDA core collection of cowpea to identify genepools, migrants, admixture, and duplicates
Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana reduce the survival of Xenopsylla brasiliensis larvae (Siphonaptera: Pulicidae).
Entomopathogenic fungi, particularly those belonging to the genera Metarhizium and Beauveria have shown great promise as arthropod vector control tools. These agents, however, have not been evaluated against flea vectors of plague. A 3-h exposure to the fungi coated paper at a concentration of 2 × 108 conidia m-2 infected >90% of flea larvae cadavers in the treatment groups. The infection reduced the survival of larvae that had been exposed to fungus relative to controls. The daily risk of dying was four- and over three-fold greater in larvae exposed to M. anisopliae (HR = 4, p<0.001) and B. bassiana (HR = 3.5, p<0.001) respectively. Both fungi can successfully infect and kill larvae of X. brasiliensis with a pooled median survival time (MST±SE) of 2±0.31 days post-exposure. These findings justify further research to investigate the bio-control potential of entomopathogenic fungi against fleas.\ud
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X-Ray Spectral Study of AGN Sources Content in Some Deep Extragalactic XMM-Newton Fields
We undertake a spectral study of a sample of bright X-ray sources taken from
six XMM-Newton fields at high galactic latitudes, where AGN are the most
populous class. These six fields were chosen such that the observation had an
exposure time more than 60 ksec, had data from the EPIC-pn detector in the
full-Frame mode and lying at high galactic latitude . The analysis
started by fitting the spectra of all sources with an absorbed power-law model,
and then we fitted all the spectra with an absorbed power-law with a low energy
black-body component model.The sources for which we added a black body gave an
F-test probability of 0.01 or less (i.e. at 99% confidence level), were
recognized as sources that display soft excess. We perform a comparative
analysis of soft excess spectral parameters with respect to the underlying
power-law one for sources that satisfy this criterion. Those sources, that do
not show evidence for a soft excess, based on the F-test probability at a 99%
confidence level, were also fitted with the absorbed power-law with a low
energy black-body component model with the black-body temperature fixed at 0.1
and 0.2 keV. We establish upper limits on the soft excess flux for those
sources at these two temperatures. Finally we have made use of Aladdin
interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED)
to identify the X-ray sources in our sample. For those sources which are
identified in the NED catalogue, we make a comparative study of the soft excess
phenomenon for different types of systems
Humanitarian disaster for Rohingya refugees: impending natural hazards and worsening public health crises
Synthesis and spectral studies of 5-[3-(1,2,4-triazolyl-azo]-2,4-dihydroxybenzaldehyde(TA)and its Schiff bases with 1,3-diaminopropane(TAAP)and 1,6-diaminohexane(TAAH).Their analytical application for spectrophotometric microdetermination of cobalt(II).
Cataloged from PDF version of article.The new azo compound 5-[3-(1,2,4-triazolyl-azo]-2,4-dihydroxy-benzaldehyde (TA) and its Schiff bases with 1,3-diaminopropane
(TAAP) and 1,6-diaminohexane (TAAH) have been synthesized. The bands of diagnostic importance in the IR and the main signals
in 1
H NMR spectra are assigned. The electronic absorption spectra in pure organic solvents of different polarity and in buffer
solutions of varying pH are investigated. The quantitative description of the solvent effect on the electronic absorption spectra is
studied and their acid ionization constants are determined. Also, a new simple and sensitive method for the spectrophotometric
microdetermination of Co(II) using these compounds (TA, TAAP and TAAH) as new chromogenic reagents is established. The
developed method is successfully used for the determination of trace amounts of cobalt in authentic samples and calculation of the
distribution ratio of cobalt adsorbed on bentonite and kaolinite clay minerals.
2004 Elsevier Ltd. All rights reserved
The prevalence and distribution of the amyloidogenic transthyretin (TTR) V122I allele in Africa
Transthyretin (TTR) pV142I (rs76992529-A) is one of the 113 variants in the human TTR gene associated with systemic amyloidosis. It results from a G to A transition at a CG dinucleotide in the codon for amino acid 122 of the mature protein (TTR V122I). The allele frequency is 0.0173 in African Americans
DC link voltage control during sudden load changes in AC microgrids
Parallel inverters in AC microgrids can achieve accurate power sharing using droop control. However, different grid line impedances will result in different transient power and thus different energy being delivered or absorbed by the inverters during sudden load changes. This might lead the DC link voltage to rise beyond the trip limit causing the inverter to shut down, which reduces the reliability of the whole microgrid. This paper investigates the effect of the mismatch in line impedances on the stability of the DC link voltage during a sudden load changes and proposes a scheme to control the DC link voltage during disturbances. Simulation and experimental results are presented to verify the efficacy of the proposed controller
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