47 research outputs found

    Cytological, Phenological and Molecular Characterization of B (S)-Genome Synthetic Hexaploids (2n = 6x = 42; AABBSS)

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    The B(S) genome diploids (2n = 2x = 14) are a unique reservoir of genetic diversity that can provide wheat breeders a rich source of allelic variation for stress traits that limit productivity. Restricted in practical use essentially due to their complex chromosomal behavior, these diploids have been in limited practical usage. The classic utilization example has been the suppression activity of the Ph locus and role in alien genetic transfer aspects that has been a standard in cytogenetic manipulation studies. For applied efforts focusing on Aegilops speltoides researchers in CIMMYT initiated an ambitious program to make AABBBB(SS) synthetics and made progress by generating over 50 such synthetics. Of these 20 were available for this study in which phenology and powdery mildew screening were evaluated. Four of these 20 synthetics appeared to be useful sources for further exploitation in breeding. These were entries 6, 9, 10 and 11 suited for exploitation in pre-breeding, with positive phenological characters particularly high thousand-kernel weight and are cytologically near euploid at 2n = 6x = 42. The subtle hyper (43) and hypoploid number would not negate their applied use potential. Preference however goes to genotypes 9 and 11

    Impact of maternal respiratory infections on low birth weight - a community based longitudinal study in an urban setting in Pakistan

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    Background: The health of mothers and their newborns is intricately related. The weight of the infant at birth is a powerful predictor of infant growth and survival, and is considered to be partly dependent on maternal health and nutrition during pregnancy. We conducted a longitudinal study in an urban community within Karachi to determine maternal predictors of newborn birth weight.Methods: Four hundred pregnant women were enrolled in the study during the period 2011-2013. Data related to symptoms of acute respiratory illness (fever, cough, difficulty breathing, runny nose, sore throat, headache, chills, and myalgia/lethargy) in the pregnant women were collected weekly until delivery. Birth weight of the newborn was recorded within 14days of delivery and the weight of \u3c 2.5kg was classified as low birth weight (LBW).Results: A total of 9,853 symptom episodes were recorded of fever, cough, difficulty breathing, runny nose, sore throat, headache, chills, myalgias/lethargy in the enrolled pregnant women during the study. Out of 243 pregnant women whose newborns were weighed within 14days of birth, LBW proportion was 21% (n=53). On multivariate analysis, independent significant risk factors noted for delivering LBW babies were early pregnancy weight of \u3c 57.5kg [odds ratio adjusted (ORadj)=5.1, 95% CI: (1.3, 19.9)] and gestational age [ORadj=0.3, 95% CI (0.2, 0.7) for every one week increase in gestational age]. Among mothers with high socioeconomic status (SES), every 50-unit increase in the number of episodes of respiratory illness/100weeks of pregnancy had a trend of association with an increased risk of delivering LBW infants [ORadj=1.7, 95% CI: (1.0, 3.1)]. However, among mothers belonging to low SES, there was no association of the number of episodes of maternal respiratory illness during pregnancy with infants having LBW [ORadj=0.9, 95% CI: (0.5, 3.5)].CONCLUSIONS: While overall respiratory illnesses during pregnancy did not impact newborn weight in our study, we found this trend in the sub-group of mothers belonging to the higher SES. Whether this is because in mothers belonging to lower SES, the effects of respiratory illnesses were overshadowed by other risk factors associated with poverty need to be further studied

    Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

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    Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

    Solid Phase Extraction of Thorium on Multiwalled Carbon Nanotubes Prior to UV-Vis Spectrophotometric Determination in Ore Samples

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    A separation-preconcentration method is presented for the solid phase extraction (SPE) of trace thorium(IV) as its arsenazo III complex in environmental samples on multi-walled carbon nanotubes (MWCNTs) by UV-Vis spectrophotometry. The influence of pH of the sample solutions, amount of arsenazo III, eluent type and volume, and sample volume were studied. The effects of the matrix ions were also examined. The detection limits (LOD) and quantification limits (LOQ) of 0.035 and 0.12 mu g/L, respectively, were obtained. An enrichment factor of 40 was achieved for Th(IV) and the relative standard deviation was < 5 %. The presented method was applied for the determination of thorium in an ore sample with satisfactory results

    Enrichment of Copper as 1-(2-Pyridylazo)-2-Naphthol Complex by the Combination of Dispersive Liquid-Liquid Microextraction/Flame Atomic Absorption Spectrometry

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    A rapid, simple, selective, economical, and sensitive dispersive liquid-liquid microextraction methodology has been established for the preconcentration of copper (Cu) at trace levels. The Cu(II) was complexed with 1-(2-pyridylazo)-2-naphthol; ethanol and carbon tetrachloride were used as disperser and extraction solvents, respectively. To obtain quantitative recovery of Cu(II), the effects of parameters influencing its extraction efficiency and subsequent determinations, i.e., pH, amount of complexing reagent, extraction time, and type and volume of disperser and extraction solvents, were examined. LOD and LOQ were 0.06 and 0.20 mu g/L, respectively. The enrichment factor of the proposed method was 60, and the RSD <5%. TMDA 51.3 and TMDA 70 fortified water certified reference materials were analyzed for validation of the procedure. The developed microextraction procedure has been used for the preconcentration of Cu(II) in water samples with acceptable results

    Karnal bunt resistance in synthetic hexaploid wheats (SH) derived from durum wheat × Aegilops tauschii combinations and in some SH × bread wheat derivatives

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    Bridge crosses utilizing the D genome synthetic hexaploids (SH), Triticum turgidum / Aegilops tauschii (2n = 6x = 42, AABBDD), are a potent means of improving bread wheat ( T. aestivum ) for biotic and abiotic stresses. The synthetic germplasm enables incorporation of the genetic diversity of T. turgidum cultivars together with the attributes of the Ae. tauschii accessions. In this research, SH wheats were screened for karnal bunt in Obregon, Mexico over six crop cycles and several SHs were earlier identified with an immune response. These SHs have unique Ae. tauschii accessions as parents. Phenologically descriptors and additional trait evaluations led us to develop a sub-set of the most desirable combinations for wheat breeding. The SH wheats are generally tall, late to mature, have good agronomic type, and are non-free threshing with a high 1000 kernel weight. All have a spring growth habit with several possessing multiple stress resistances. The resistance exhibited by SH wheats has been transferred into elite but KB susceptible bread wheat cultivars thus generating a new and unique genetic resource that can be readily exploited by conventional breeding programs
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