2,460 research outputs found

    Performance of small-seeded common bean from the second selection cycle and multiple-cross intra- and interracial populations

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    Twenty experimental lines of small-seeded common^bean (Phaseolus vulgaris L.) of Middle American origin from the second cycle of selection (SCS) in multiple cross intra- and interracial populations were evaluated with two control cultivars from the first cycle of selection (FCS) derived from single-cross intraracial populations and three standard controls at three locations for 3 yr (1988-1990) in Colombia. A 5 x 5 lattice design with four replications was used. Each plot consisted of four rows, 5 m long in the first year and 7 m long in the next 2 years. To develop experimental lines in both selection cycles, visual mass selection for seed yield and/or resistance tb diseases in individual plants and plant-to-progeny rows was practiced in early generations. The F2 and F3 were managed by the single-pod bulk method followed by the single plant harvests (F4 or F5), progeny tests (F5 or F6), and seed increases (F6 or F7). The F4- or F5-derived lines were tested for seed yield in F7 or F8. Thirteen lines from the SCS outyielded both control cultivars from the FCS and one standard control. However, only two lines, A 785 and A774, from the SCS outyielded the best standard control, cultivar Carioca, by an average of 7.77o. Both lines were derived from interracial populations involving high-yielding parents possessing positive general combining ability for seed yield. Most improved lines from the SCS possessed higher yield per day and higher disease resistance. No apparent changes were recorded in days to maturity and 100-seed weight for high-yielding lines. Late-maturing lines usually had lower yield and yield per day

    Use of interracial hybridization in breeding the race Durango common bean

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    Recently, interracial hybridization was used successfully in breeding common bean (Phaseolus vulgaris L.), but its use has not been adequately documented. Approximately 125 lines with medium-sized seed were selected in the first cycle, mostly from race Durango x race Mesoamerica (both from the Middle American domestication center) single- and multiple-cross populations, for disease resistance and race Durango characteristics. Fifteen of these improved lines, three race Durango control cultivars, and one control cultivar each from races Jalisco and Mesoamerica were evaluated for 3 yr (1989-1991) at three locations in Colombia. A randomized complete block design with three replications was used. Lines were developed using visual mass selection for seed yield and/or resistance to diseases in F2 and F3, followed by single plant harvests in F4 or F5 and seed increases in F6 or F7. Lines resistant to bean common mosaic virus and possessing other desirable traits were yield-tested in F7 or F8. All but two lines outyielded Alteho and Flor de Mayo, the highest yielding control cultivars from races Durango and Jalisco, respectively. Two lines also outyielded Carioca, the race Mesoamerica control cultivar. Improved lines tended to possess higher yield per day. All lines were resistant to bean common mosaic virus and most lines also carried a high level of resistance to anthracnose. Plant, seed, and maturity characteristics of most improved lines were similar to those of race Durango control cultivars. These results support the use of interracial hybridization in improving race Durango common bean

    Eugenol: A Promising Building Block for Synthesis of Radically Polymerizable Monomers

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    Eugenol, a natural phenol currently mainly obtained from clove oil, is an interesting aromatic building block for the synthesis of novel biobased monomers. It can also be obtained from lignin depolymerization, becoming a promising building block due to lignin availability as biomass feedstock. The synthesis of eight monomers derived from eugenol containing polymerizable functional groups is achieved. The (meth)acrylation of eugenol, isoeugenol, and dihydroeugenol is performed and the solution homopolymerization of these biobased monomers is studied. Moreover, aiming to prepare functional polymers, the introduction of epoxy and cyclic carbonate groups is executed via modification of the allylic double bond present in eugenol derived methacrylate. Thus, a novel platform of versatile biobased monomers derived from eugenol is presented, opening the opportunity to use them in a wide range of polymerization processes and applications

    Gnathostomosis, an emerging foodborne zoonotic disease in Acapulco, Mexico.

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    Between 1993 and 1997, 98 gnathostomosis cases were clinically identified in Acapulco, Mexico. Intermittent cutaneous migratory swellings were the commonest manifestation. Larvae were identified in 26 cases, while in 72, final diagnosis was made on the basis of epidemiologic data, food habits, and positive enzyme-linked immunosorbent assay and Western blot results

    Photoinduced polymerization of eugenol-derived methacrylates

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    Biobased monomers have been used to replace their petroleum counterparts in the synthesis of polymers that are aimed at different applications. However, environmentally friendly polymerization processes are also essential to guarantee greener materials. Thus, photoinduced polymerization, which is low-energy consuming and solvent-free, rises as a suitable option. In this work, eugenol-, isoeugenol-, and dihydroeugenol-derived methacrylates are employed in radical photopolymerization to produce biobased polymers. The polymerization is monitored in the absence and presence of a photoinitiator and under air or protected from air, using Real-Time Fourier Transform Infrared Spectroscopy. The polymerization rate of the methacrylate double bonds was affected by the presence and reactivity of the allyl and propenyl groups in the eugenol- and isoeugenol-derived methacrylates, respectively. These groups are involved in radical addition, degradative chain transfer, and termination reactions, yielding crosslinked polymers. The materials, in the form of films, are characterized by differential scanning calorimetry, thermogravimetric, and contact angle analyses

    Predictors of diabetes risk in urban and rural areas in Colombia

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    Background: Nutritional habits low in fruits and vegetables and sedentary lifestyle are associated with a higher risk of developing Type 2 Diabetes (T2D). However, it is important to assess differences between urban and rural areas. This study aimed to analyze the associations between the risk of developing T2D and setting in the Colombian north coast in 2017. Methods: This cross-sectional study included 1,005 subjects. Data was collected by interviewing self-identified members of an urban community and a rural-indigenous population. The interaction terms were evaluated as well as the confounders. Then, adjusted binary logistic regressions were used to estimate the odds ratio (OR) and 95% Confidence Intervals (CI). Results: subjects with a high risk of T2D are more likely to belong to the urban setting (OR = 1.908; 95%CI = 1.201-2.01) compared with those with lower T2D after adjusting for age, Body Mass Index (BMI), physical activity, history of high levels of glycemia, and diabetes in relatives. Conclusions: Urban communities are more likely to have T2D compared with rural-indigenous populations. These populations have differences from the cultural context, including personal, and lifestyle factors.Peer reviewe

    First results from the Very Small Array -- IV. Cosmological parameter estimation

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    We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres

    Observations of the Cosmic Microwave Background and Galactic Foregrounds at 12-17 GHz with the COSMOSOMAS Experiment

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    (Abridged) We present the analysis of the first 18 months of data obtained with the COSMOSOMAS experiment at the Teide Observatory (Tenerife). Three maps have been obtained at 12.7, 14.7 and 16.3 GHz covering 9000 square degrees each with a resolution of ~1 degree and with sensitivities 49, 59 and 115 muK per beam respectively. These data in conjuction with the WMAP first year maps have revealed that the Cosmic Microwave Background (CMB) is the dominant astronomical signal at high galatic latitude in the three COSMOSOMAS channels with an average amplitude of 29.7+/- 1.0 \muK (68% c.l. not including calibration errors). This value is in agreement with the predicted CMB signal in the COSMOSOMAS maps using the best fit Lambda-CDM model to the WMAP power spectrum. Cross-correlation of COSMOSOMAS data with the DIRBE map at 100 \mu m shows the existence of a common signal with amplitude 7.4+/- 1.1, 7.5+/- 1.1, and 6.5+/-2.3 muK in the 12.7, 14.7 and 16.3 GHz COSMOSOMAS maps at |b|>30^\deg. Using the WMAP data we find this DIRBE correlated signal rises from high to low frequencies flattening below ~20 GHz. At higher galactic latitudes the average amplitude of the correlated signal with the DIRBE maps decreases slightly. The frequency behaviour of the COSMOSOMAS/WMAP correlated signal with DIRBE is not compatible with the expected tendency for thermal dust. A study of the H-alpha emission maps do not support free-free as a major contributor to that signal. Our results provide evidence of a new galactic foreground with properties compatible with those predicted by the spinning dust models.Comment: 11 pages, 21 figures. Submitted to MNRAS. For paper with figures at full resolution, see http://www.iac.es/project/cmb/cosmosomas

    First results from the Very Small Array -- I. Observational methods

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    The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from other CMB interferometers with the result that different systematic errors are expected. We have tested the operation of the VSA with a variety of blank-field and calibrator observations and cross-checked its calibration scale against independent measurements. We find that systematic effects can be suppressed below the thermal noise level in long observations; the overall calibration accuracy of the flux density scale is 3.5 percent and is limited by the external absolute calibration scale.Comment: 9 pages, 10 figures, MNRAS in press (Minor revisions

    The Brazilian Tunable Filter Imager for the SOAR telescope

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    This paper presents a new Tunable Filter Instrument for the SOAR telescope. The Brazilian Tunable Filter Imager (BTFI) is a versatile, new technology, tunable optical imager to be used in seeing-limited mode and at higher spatial fidelity using the SAM Ground-Layer Adaptive Optics facility at the SOAR telescope. The instrument opens important new science capabilities for the SOAR community, from studies of the centers of nearby galaxies and the insterstellar medium to statistical cosmological investigations. The BTFI takes advantage of three new technologies. The imaging Bragg Tunable Filter concept utilizes Volume Phase Holographic Gratings in a double-pass configuration, as a tunable filter, while a new Fabry-Perot (FP) concept involves technologies which allow a single FP etalon to act over a large range of interference orders and spectral resolutions. Both technologies will be in the same instrument. Spectral resolutions spanning the range between 25 and 30,000 can be achieved through the use of iBTF at low resolution and scanning FPs beyond R ~2,000. The third new technologies in BTFI is the use of EMCCDs for rapid and cyclically wavelength scanning thus mitigating the damaging effect of atmospheric variability through data acquisition. An additional important feature of the instrument is that it has two optical channels which allow for the simultaneous recording of the narrow-band, filtered image with the remaining (complementary) broad-band light. This avoids the uncertainties inherent in tunable filter imaging using a single detector. The system was designed to supply tunable filter imaging with a field-of-view of 3 arcmin on a side, sampled at 0.12" for direct Nasmyth seeing-limited area spectroscopy and for SAM's visitor instrument port for GLAO-fed area spectroscopy. The instrument has seen first light, as a SOAR visitor instrument. It is now in comissioning phase.Comment: accepted in PAS
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