Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Sci Food Agric ; 100(2): 634-647, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31591722

RESUMO

BACKGROUND: Vitamin A deficiency (VAD) is widespread in sub-Saharan Africa (SSA). Unlike in developed countries, where the main source of vitamin A comes from meat, the diet of poor populations in SSA is largely plant based. It is thus important to identify local / popular plants with higher vitamin A content for combating VAD. Banana (including plantains) is an important staple food crop in this region. The identification and promotion of vitamin A-rich banana cultivars could contribute significantly to the alleviation of VAD in areas heavily dependent on the crop. We assessed pro-vitamin A carotenoid (pVACs) content in the fruit pulp of 48 local plantains from eastern Democratic Republic of Congo, to identify cultivars that could help reduce VAD, especially among young children and women of reproductive age. RESULTS: Mean pVACs content varied from 175-1756 µg/100 gfw in ripe fruits. Significant increases (P < 0.001) in total pVACs content occurred after ripening in all cultivars except 'UCG II'. Retinol activity equivalents (RAE) in ripe fruits ranged from 12-113 µg/100 gfw. Fifteen plantain cultivars, including 'Adili II', 'Nzirabahima', 'Mayayi', 'Buembe', and 'Sanza Tatu' (associated with RAE values of 44 µg/100 gfw and above) can be considered as good sources of pVACs. Modest consumption (250 or 500 gfw) of the fruit pulp of the five best plantain cultivars at ripening stage 5 meets between 39-71% and 44-81% of vitamin A dietary reference intake (DRI) respectively, for children below 5 years old and women of reproductive age. CONCLUSION: The 15 best plantain cultivars (especially the top 5) could potentially be introduced / promoted as alternative sources of pro-vitamin A in banana-dependent communities, and help to reduce cases of VAD substantially. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Carotenoides/análise , Musa/química , Vitamina A/análise , Adolescente , Adulto , Carotenoides/metabolismo , Pré-Escolar , República Democrática do Congo , Feminino , Frutas/química , Frutas/metabolismo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Musa/classificação , Musa/metabolismo , Provitaminas/análise , Vitamina A/metabolismo , Deficiência de Vitamina A/dietoterapia , Deficiência de Vitamina A/metabolismo , Adulto Jovem
2.
J Sci Food Agric ; 99(13): 5662-5670, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31150567

RESUMO

BACKGROUND: The fruit of two apple cultivars - 'Braeburn', which is susceptible to inoculation with Botrytis cinerea, and the less susceptible cv. 'Golden Delicious' - were investigated with respect to their response to inoculation with B. cinerea. Successful infection by B. cinerea leads to an oxidative burst and perturbation of plant redox homeostasis. To investigate the interaction between apple fruit and B. cinerea, antioxidant metabolism in fruit samples from sun-exposed and shaded sides of different tissue types was measured over time. RESULTS: The sun-exposed tissue of 'Braeburn' had higher initial levels of total vitamin C in the peel and phenolic compounds in the flesh than 'Golden Delicious', despite its greater susceptibility to gray mold. A substantial antioxidant response was recorded in diseased 'Braeburn' fruit 14 days after inoculation, which involved an elevated superoxide dismutase activity and ascorbate peroxidase activity, a progressive oxidation of total vitamin C, and a decrease in peroxidase activity and phenolic content. Disease development was slower on the sun-exposed sides than on the shaded sides. CONCLUSION: The two cultivars appeared to utilize different strategies to defend themselves against B. cinerea. 'Golden Delicious' almost entirely escaped infection. Preharvest exposure of apple fruit to high light / temperature stress appears to prepare them to better resist subsequent postharvest attack and disease. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Botrytis/fisiologia , Frutas/microbiologia , Malus/microbiologia , Doenças das Plantas/microbiologia , Ácido Ascórbico/análise , Ácido Ascórbico/metabolismo , Cor , Frutas/química , Frutas/metabolismo , Malus/química , Malus/metabolismo , Fenóis/química , Fenóis/metabolismo , Explosão Respiratória
3.
Environ Sci Technol ; 51(6): 3336-3345, 2017 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-28244744

RESUMO

Long-term ultrafine particle (UFP) exposure estimates at a fine spatial scale are needed for epidemiological studies. Land use regression (LUR) models were developed and evaluated for six European areas based on repeated 30 min monitoring following standardized protocols. In each area; Basel (Switzerland), Heraklion (Greece), Amsterdam, Maastricht, and Utrecht ("The Netherlands"), Norwich (United Kingdom), Sabadell (Spain), and Turin (Italy), 160-240 sites were monitored to develop LUR models by supervised stepwise selection of GIS predictors. For each area and all areas combined, 10 models were developed in stratified random selections of 90% of sites. UFP prediction robustness was evaluated with the intraclass correlation coefficient (ICC) at 31-50 external sites per area. Models from Basel and The Netherlands were validated against repeated 24 h outdoor measurements. Structure and model R2 of local models were similar within, but varied between areas (e.g., 38-43% Turin; 25-31% Sabadell). Robustness of predictions within areas was high (ICC 0.73-0.98). External validation R2 was 53% in Basel and 50% in The Netherlands. Combined area models were robust (ICC 0.93-1.00) and explained UFP variation almost equally well as local models. In conclusion, robust UFP LUR models could be developed on short-term monitoring, explaining around 50% of spatial variance in longer-term measurements.


Assuntos
Poluição do Ar , Material Particulado , Poluentes Atmosféricos , Monitoramento Ambiental , Modelos Teóricos
4.
BMC Public Health ; 17(1): 712, 2017 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-28915873

RESUMO

BACKGROUND: There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements. METHODS/DESIGN: A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR). Additionally, daily pollen levels (mould spores, tree, grass and weed pollen) in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO) and the presence of atopy (Phadiatop). DISCUSSION: This research applies state of the art exposure assessment approaches to characterize the effects of ambient air pollutants on childhood respiratory health, with a specific focus on asthma and markers of airway inflammation (FeNO) in South African informal settlement areas by considering also pollen counts and meteorological factors. The study will generate crucial data on air pollution and asthma in low income settings in sub-Sahara Africa that is lacking in the international literature.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Asma/epidemiologia , Exposição Ambiental/efeitos adversos , Doenças Respiratórias/epidemiologia , Adolescente , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Alérgenos/efeitos adversos , Alérgenos/análise , Feminino , Humanos , Masculino , Conceitos Meteorológicos , Pólen/efeitos adversos , Estudos Prospectivos , Estações do Ano , África do Sul/epidemiologia
5.
Environ Health ; 15: 53, 2016 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-27089921

RESUMO

BACKGROUND: Land Use Regression (LUR) is a popular method to explain and predict spatial contrasts in air pollution concentrations, but LUR models for ultrafine particles, such as particle number concentration (PNC) are especially scarce. Moreover, no models have been previously presented for the lung deposited surface area (LDSA) of ultrafine particles. The additional value of ultrafine particle metrics has not been well investigated due to lack of exposure measurements and models. METHODS: Air pollution measurements were performed in 2011 and 2012 in the eight areas of the Swiss SAPALDIA study at up to 40 sites per area for NO2 and at 20 sites in four areas for markers of particulate air pollution. We developed multi-area LUR models for biannual average concentrations of PM2.5, PM2.5 absorbance, PM10, PMcoarse, PNC and LDSA, as well as alpine, non-alpine and study area specific models for NO2, using predictor variables which were available at a national level. Models were validated using leave-one-out cross-validation, as well as independent external validation with routine monitoring data. RESULTS: Model explained variance (R(2)) was moderate for the various PM mass fractions PM2.5 (0.57), PM10 (0.63) and PMcoarse (0.45), and was high for PM2.5 absorbance (0.81), PNC (0.87) and LDSA (0.91). Study-area specific LUR models for NO2 (R(2) range 0.52-0.89) outperformed combined-area alpine (R (2) = 0.53) and non-alpine (R (2) = 0.65) models in terms of both cross-validation and independent external validation, and were better able to account for between-area variability. Predictor variables related to traffic and national dispersion model estimates were important predictors. CONCLUSIONS: LUR models for all pollutants captured spatial variability of long-term average concentrations, performed adequately in validation, and could be successfully applied to the SAPALDIA cohort. Dispersion model predictions or area indicators served well to capture the between area variance. For NO2, applying study-area specific models was preferable over applying combined-area alpine/non-alpine models. Correlations between pollutants were higher in the model predictions than in the measurements, so it will remain challenging to disentangle their health effects.


Assuntos
Poluentes Atmosféricos/análise , Pulmão/anatomia & histologia , Modelos Teóricos , Dióxido de Nitrogênio/análise , Material Particulado/análise , Poluição do Ar/análise , Altitude , Sistemas de Informação Geográfica , Humanos , Densidade Demográfica , Análise de Regressão , Propriedades de Superfície , Suíça
6.
Am J Respir Crit Care Med ; 191(12): 1413-21, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25867003

RESUMO

RATIONALE: More than 25 million American children breathe polluted air on diesel school buses. Emission reduction policies exist, but the health impacts to individual children have not been evaluated. METHODS: Using a natural experiment, we characterized the exposures and health of 275 school bus riders before, during, and after the adoption of clean technologies and fuels between 2005 and 2009. Air pollution was measured during 597 trips on 188 school buses. Repeated measures of exhaled nitric oxide (FeNO), lung function (FEV1, FVC), and absenteeism were also collected monthly (1,768 visits). Mixed-effects models longitudinally related the adoption of diesel oxidation catalysts (DOCs), closed crankcase ventilation systems (CCVs), ultralow-sulfur diesel (ULSD), or biodiesel with exposures and health. MEASUREMENTS AND MAIN RESULTS: Fine and ultrafine particle concentrations were 10-50% lower on buses using ULSD, DOCs, and/or CCVs. ULSD adoption was also associated with reduced FeNO (-16% [95% confidence interval (CI), -21 to -10%]), greater changes in FVC and FEV1 (0.02 [95% CI, 0.003 to 0.05] and 0.01 [95% CI, -0.006 to 0.03] L/yr, respectively), and lower absenteeism (-8% [95% CI, -16.0 to -0.7%]), with stronger associations among patients with asthma. DOCs, and to a lesser extent CCVs, also were associated with improved FeNO, FVC growth, and absenteeism, but these findings were primarily restricted to patients with persistent asthma and were often sensitive to control for ULSD. No health benefits were noted for biodiesel. Extrapolating to the U.S. population, changed fuel/technologies likely reduced absenteeism by more than 14 million/yr. CONCLUSIONS: National and local diesel policies appear to have reduced children's exposures and improved health.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/prevenção & controle , Gasolina/estatística & dados numéricos , Nível de Saúde , Veículos Automotores/estatística & dados numéricos , Emissões de Veículos/prevenção & controle , Absenteísmo , Biocombustíveis/estatística & dados numéricos , Criança , Monitoramento Ambiental/estatística & dados numéricos , Feminino , Humanos , Estudos Longitudinais , Masculino , Óxido Nítrico/metabolismo , Testes de Função Respiratória/estatística & dados numéricos , Washington
7.
J Obstet Gynaecol ; 36(5): 631-4, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27012598

RESUMO

This retrospective audit reviewed all ectopic pregnancies over a 5-year period in a district general hospital setting. Of 215 ectopic pregnancies identified, notes were available for 208 (97%). 202 cases were determined to have been diagnosed and managed as ectopic pregnancies. Six cases were excluded as they were pregnancies of unknown location managed as such. The proportion of patients managed non-surgically has increased following the introduction of our consultant-led early pregnancy assessment unit from 25% prior to 31% currently. The success rates have improved in both those managed expectantly (50%-73%) and those with methotrexate (75%-90%). There has been a corresponding drop in those managed surgically from 75% to 69%, and a reduction in negative laparoscopies from 13% to 6%. Provided recommended criteria and follow-up are adhered to, non-surgical management has been shown to have comparative safety to traditional surgical management with acceptable efficacy and patient acceptability.


Assuntos
Abortivos não Esteroides , Aborto Induzido/tendências , Laparoscopia/tendências , Metotrexato , Gravidez Ectópica/terapia , Aborto Induzido/métodos , Adolescente , Adulto , Feminino , Humanos , Auditoria Médica , Pessoa de Meia-Idade , Gravidez , Estudos Retrospectivos , Adulto Jovem
8.
J Obstet Gynaecol ; 36(4): 437-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27002651

RESUMO

This retrospective cohort study reviewed the diagnosis of all ectopic pregnancies within a district general hospital over a 5-year period after the establishment of a dedicated Early Pregnancy Assessment Unit (EPAU). Of 215 ectopic pregnancies identified, notes were available for 208 (97%). Two-hundred and two cases were determined to have been diagnosed and managed as ectopic pregnancies. Six cases were excluded as they were pregnancies of unknown location managed as such. Overall, 91% were diagnosed by ultrasound scan, 5% were diagnosed clinically and 3% were diagnosed on serial human chorionic gonadotrophin (hCG) levels. This study found that the introduction of a dedicated, multi-professional, EPAU with a stable workforce improved ultrasound visualisation of ectopic pregnancies at first ultrasound scan from 22% prior to its commencement, to 61% over this period. The improvement in positive scan diagnosis of ectopic pregnancy was associated with a reduction in negative laparoscopy rate from 13% to 6%.


Assuntos
Testes de Gravidez/estatística & dados numéricos , Gravidez Ectópica/diagnóstico por imagem , Ultrassonografia Pré-Natal/estatística & dados numéricos , Adolescente , Adulto , Gonadotropina Coriônica Humana Subunidade beta , Reações Falso-Positivas , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Testes de Gravidez/métodos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
9.
Environ Sci Technol ; 49(5): 2709-15, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25648954

RESUMO

Although there is evidence that ultrafine particles (UFP) do affect human health there are currently no legal ambient standards. The main reasons are the absence of spatially resolved exposure data to investigate long-term health effects and the challenge of defining representative reference sites for monitoring given the high dependence of UFP on proximity to sources. The objectives of this study were to evaluate the spatial distribution of UFP in four areas of the Swiss Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) and to investigate the representativeness of routine air monitoring stations for residential sites in these areas. Repeated UFP measurements during three seasons have been conducted at a total of 80 residential sites and four area specific reference sites over a median duration of 7 days. Arithmetic mean residential PNC scattered around the median of 10,800 particles/cm(3) (interquartile range [IQR] = 7800 particles/cm(3)). Spatial within area contrasts (90th/10th percentile ratios) were around two; increased contrasts were observed during weekday rush-hours. Temporal UFP patterns were comparable at reference and residential sites in all areas. Our data show that central monitoring sites can represent residential conditions when locations are well chosen with respect to the local sources--namely traffic. For epidemiological research, locally resolved spatial models are needed to estimate individuals' long-term exposures to UFP of outdoor origin at home, during commute and at work.


Assuntos
Poluentes Atmosféricos/análise , Material Particulado/análise , Adulto , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Habitação , Humanos , Masculino , Modelos Teóricos , Saúde da População Rural , Estações do Ano , Suíça , Saúde da População Urbana
11.
Electrophoresis ; 35(10): 1395-1405, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24921068

RESUMO

This study represents a systematic evaluation of protocols for protein extraction and cleanup for fruit proteomic analysis. Procedures were optimized using pooled lyophilized banana fruit pulp, which is known to be particularly tricky due to high concentrations of soluble polysaccharides, phenolics, and other substances that interfere with protein extraction and purification. A total of 18 combinations of three protein extraction procedures (SDS-based, Triton X-100-based, and phenol-based), three protein precipitating agents (ammonium acetate/methanol, TCA/acetone, and acetone), and two resolubilization buffers (classical Rabilloud and the so-called R2D2) were compared for total protein yields and efficiency of recovery. The results demonstrate that while losses in total recovered protein are unavoidable, the degree of these losses depends on the method combinations used. Combinations based on buffer-saturated phenol always gave the highest yields, and overall recovery and purity was highest when acetone was combined with the R2D2 buffer for protein purification and concentration. Comparative 2D-PAGE analysis confirmed that this method combination produced high-quality and reproducible gels and the largest numbers of spots per gel. The usefulness of this methodology was demonstrated on ripe fruits from several other species and shown to give excellent results.


Assuntos
Frutas/química , Proteínas de Plantas/química , Proteômica , Eletroforese em Gel Bidimensional , Liofilização
12.
Atmos Environ (1994) ; 98: 492-499, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25364294

RESUMO

A mobile monitoring platform developed at the University of Washington Center for Clean Air Research (CCAR) measured 10 pollutant metrics (10 s measurements at an average speed of 22 km/hr) in two neighborhoods bordering a major interstate in Albuquerque, NM, USA from April 18-24 2012. 5 days of data sharing a common downwind orientation with respect to the roadway were analyzed. The aggregate results show a three-fold increase in black carbon (BC) concentrations within 10 meters of the edge of roadway, in addition to elevated nanoparticle concentration and particulate matter with aerodynamic diameter < 1 µm (PN1) concentrations. A 30% reduction in ozone concentration near the roadway was observed, anti-correlated with an increase in the oxides of nitrogen (NOx). In this study, the pollutants measured have been expanded to include polycyclic aromatic hydrocarbons (PAH), particle size distribution (0.25-32 µm), and ultra-violet absorbing particulate matter (UVPM). The raster sampling scheme combined with spatial and temporal measurement alignment provide a measure of variability in the near roadway concentrations, and allow us to use a principal component analysis to identify multi-pollutant features and analyze their roadway influences.

13.
Bull Environ Contam Toxicol ; 93(6): 716-21, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24923470

RESUMO

This study examined the spatial distribution of total mercury (THg) and total arsenic (TAs) in water, soil and cassava (Manihot esculenta) (leaves and roots) samples taken from areas in Rwamagasa village in northwestern Tanzania where daily living activities occur in close proximity to extensive artisanal and small scale gold mining. Results indicated that 33.3 % of the water sources had THg levels above the WHO guideline of 1.0 µg/L for safe drinking water, and 12.5 % had TAs levels above 10 µg/L. Cassava leaves were found to have higher THg (ranging from 8.3 to 167 µg/kg) and TAs (ranging from 60 to 1,120 µg/kg) levels than cassava roots, which ranged between 1.2-8.3 µg/kg for THg and 25-310 µg/kg for TAs. Concentrations of THg and TAs in soil samples ranged between 5.8-1,759 and 183-20,298 µg/kg, respectively. Both THg and TAs were found to be distributed throughout Rwamagasa village.


Assuntos
Arsênio/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Manihot/metabolismo , Mercúrio/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Arsênio/metabolismo , Exposição Ambiental , Humanos , Espectrometria de Massas , Mercúrio/metabolismo , Mineração , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo , Espectrofotometria Atômica , Tanzânia
14.
BMC Genomics ; 14: 683, 2013 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-24094114

RESUMO

BACKGROUND: Modern banana cultivars are primarily interspecific triploid hybrids of two species, Musa acuminata and Musa balbisiana, which respectively contribute the A- and B-genomes. The M. balbisiana genome has been associated with improved vigour and tolerance to biotic and abiotic stresses and is thus a target for Musa breeding programs. However, while a reference M. acuminata genome has recently been released (Nature 488:213-217, 2012), little sequence data is available for the corresponding B-genome.To address these problems we carried out Next Generation gDNA sequencing of the wild diploid M. balbisiana variety 'Pisang Klutuk Wulung' (PKW). Our strategy was to align PKW gDNA reads against the published A-genome and to extract the mapped consensus sequences for subsequent rounds of evaluation and gene annotation. RESULTS: The resulting B-genome is 79% the size of the A-genome, and contains 36,638 predicted functional gene sequences which is nearly identical to the 36,542 of the A-genome. There is substantial sequence divergence from the A-genome at a frequency of 1 homozygous SNP per 23.1 bp, and a high degree of heterozygosity corresponding to one heterozygous SNP per 55.9 bp. Using expressed small RNA data, a similar number of microRNA sequences were predicted in both A- and B-genomes, but additional novel miRNAs were detected, including some that are unique to each genome. The usefulness of this B-genome sequence was evaluated by mapping RNA-seq data from a set of triploid AAA and AAB hybrids simultaneously to both genomes. Results for the plantains demonstrated the expected 2:1 distribution of reads across the A- and B-genomes, but for the AAA genomes, results show they contain regions of significant homology to the B-genome supporting proposals that there has been a history of interspecific recombination between homeologous A and B chromosomes in Musa hybrids. CONCLUSIONS: We have generated and annotated a draft reference Musa B-genome and demonstrate that this can be used for molecular genetic mapping of gene transcripts and small RNA expression data from several allopolyploid banana cultivars. This draft therefore represents a valuable resource to support the study of metabolism in inter- and intraspecific triploid Musa hybrids and to help direct breeding programs.


Assuntos
Genoma de Planta/genética , Hibridização Genética , Musa/genética , Poliploidia , Sequência de Bases , Cromossomos de Plantas/genética , DNA de Plantas/genética , Etiquetas de Sequências Expressas , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , MicroRNAs/metabolismo , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNA , Especificidade da Espécie
15.
Plant Physiol ; 160(3): 1613-29, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23001142

RESUMO

To identify the genetic factors underlying the regulation of fruit vitamin C (L-ascorbic acid [AsA]) concentrations, quantitative trait loci (QTL) studies were carried out in an F1 progeny derived from a cross between the apple (Malus × domestica) cultivars Telamon and Braeburn over three years. QTL were identified for AsA, glutathione, total antioxidant activity in both flesh and skin tissues, and various quality traits, including flesh browning. Four regions on chromosomes 10, 11, 16, and 17 contained stable fruit AsA-QTL clusters. Mapping of AsA metabolic genes identified colocations between orthologs of GDP-L-galactose phosphorylase (GGP), dehydroascorbate reductase (DHAR), and nucleobase-ascorbate transporter within these QTL clusters. Of particular interest are the three paralogs of MdGGP, which all colocated within AsA-QTL clusters. Allelic variants of MdGGP1 and MdGGP3 derived from the cultivar Braeburn parent were also consistently associated with higher fruit total AsA concentrations both within the mapping population (up to 10-fold) and across a range of commercial apple germplasm (up to 6-fold). Striking differences in the expression of the cv Braeburn MdGGP1 allele between fruit from high- and low-AsA genotypes clearly indicate a key role for MdGGP1 in the regulation of fruit AsA concentrations, and this MdGGP allele-specific single-nucleotide polymorphism marker represents an excellent candidate for directed breeding for enhanced fruit AsA concentrations. Interestingly, colocations were also found between MdDHAR3-3 and a stable QTL for browning in the cv Telamon parent, highlighting links between the redox status of the AsA pool and susceptibility to flesh browning.


Assuntos
Alelos , Ácido Ascórbico/metabolismo , Frutas/genética , Malus/enzimologia , Malus/genética , Monoéster Fosfórico Hidrolases/genética , Homologia de Sequência de Aminoácidos , Antioxidantes/metabolismo , Sequência de Bases , Vias Biossintéticas/genética , Mapeamento Cromossômico , Cruzamentos Genéticos , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Estudos de Associação Genética , Variação Genética , Glutationa/metabolismo , Guanosina Difosfato/metabolismo , Monoéster Fosfórico Hidrolases/química , Folhas de Planta/genética , Locos de Características Quantitativas/genética , Característica Quantitativa Herdável
16.
BMC Public Health ; 13: 74, 2013 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-23351708

RESUMO

BACKGROUND: An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. METHODS: A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. RESULTS: The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65) and 89.4% (n=143) not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9%) than females (n=36, 22.5%) with regard to mercury (x²=3.99, p<0.05). An individual's occupation category was associated with level of knowledge (x²=22.82, p=<0.001). Individuals involved in mining (n=63, 73.2%) were more knowledgeable about the negative health effects of mercury than individuals in other occupations. Of the few individuals (n=17, 10.6%) who knew about arsenic toxicity, the majority (n=10, 58.8%) were miners. CONCLUSIONS: The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy changes.


Assuntos
Arsênio/toxicidade , Conhecimentos, Atitudes e Prática em Saúde , Mercúrio/toxicidade , Mineração , Exposição Ocupacional/efeitos adversos , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Ouro , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Tanzânia , Adulto Jovem
17.
BMC Plant Biol ; 12: 239, 2012 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-23245200

RESUMO

BACKGROUND: To gain insight into the regulation of fruit ascorbic acid (AsA) pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the 'low-' and 'high-AsA' tomato cultivars 'Ailsa Craig' and 'Santorini' respectively. RESULTS: The two cultivars exhibited different profiles of total AsA (totAsA, AsA + dehydroascorbate) and AsA accumulation during ripening, but both displayed a characteristic peak in concentrations at the breaker stage. Substrate feeding experiments demonstrated that the L-galactose pathway is the main AsA biosynthetic route in tomato fruits, but that substrates from alternative pathways can increase the AsA pool at specific developmental stages. In addition, we show that young fruits display a higher AsA biosynthetic capacity than mature ones, but this does not lead to higher AsA concentrations due to either enhanced rates of AsA breakdown ('Ailsa Craig') or decreased rates of AsA recycling ('Santorini'), depending on the cultivar. In the later stages of ripening, differences in fruit totAsA-AsA concentrations of the two cultivars can be explained by differences in the rate of AsA recycling activities. Analysis of the expression of AsA metabolic genes showed that only the expression of one orthologue of GDP-L-galactose phosphorylase (SlGGP1), and of two monodehydroascorbate reductases (SlMDHAR1 and SlMDHAR3) correlated with the changes in fruit totAsA-AsA concentrations during fruit ripening in 'Ailsa Craig', and that only the expression of SlGGP1 was linked to the high AsA concentrations found in red ripe 'Santorini' fruits. CONCLUSIONS: Results indicate that 'Ailsa Craig' and 'Santorini' use complementary mechanisms to maintain the fruit AsA pool. In the low-AsA cultivar ('Ailsa Craig'), alternative routes of AsA biosynthesis may supplement biosynthesis via L-galactose, while in the high-AsA cultivar ('Santorini'), enhanced AsA recycling activities appear to be responsible for AsA accumulation in the later stages of ripening. Gene expression studies indicate that expression of SlGGP1 and two orthologues of SlMDHAR are closely correlated with totAsA-AsA concentrations during ripening and are potentially good candidates for marker development for breeding and selection.


Assuntos
Ácido Ascórbico/biossíntese , Frutas/química , Solanum lycopersicum/química , Vias Biossintéticas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glutationa/análise , Solanum lycopersicum/classificação , Solanum lycopersicum/genética
18.
Emotion ; 22(7): 1544-1553, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35420836

RESUMO

Both accurately sensing our own bodily signals and knowing whether we have accurately sensed them may contribute to a successful emotional life, but there is little evidence on whether these physiological perceptual and metacognitive abilities systematically differ between people. Here, we examined whether actors, who receive substantial training in the production, awareness, and control of emotion, and nonactor controls differed in interoceptive ability (the perception of internal bodily signals) and/or metacognition about interoceptive accuracy (awareness of that perception), and explored potential sources of individual differences in and consequences of these abilities including correlational relationships with state and trait anxiety, proxies for acting ability, and the amount of acting training. Participants performed a heartbeat detection task in which they judged whether tones were played synchronously or delayed relative to their heartbeats, and then rated their metacognitive confidence in that judgment. Cardiac interoceptive accuracy and metacognitive awareness of interoceptive accuracy were independent, and while actors' and controls' interoceptive accuracy was not significantly different, actors had consistently superior metacognitive awareness of interoception. Exploratory analyses additionally suggest that this metacognitive ability may be correlated with measures of acting ability, but not the duration of acting training. Interoceptive accuracy and metacognitive insight into that accuracy appear to be separate abilities, and while actors may be no more accurate in reading their bodies, their metacognitive insight means they know better when they're accurate and when they're not. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Interocepção , Metacognição , Ansiedade , Conscientização/fisiologia , Emoções/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Interocepção/fisiologia
19.
Sci Rep ; 12(1): 14229, 2022 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-35987959

RESUMO

Two homoeologous QTLs for number of spikelets per spike (SPS) were mapped on chromosomes 7AL and 7BL using two wheat MAGIC populations. Sets of lines contrasting for the QTL on 7AL were developed which allowed for the validation and fine mapping of the 7AL QTL and for the identification of a previously described candidate gene, WHEAT ORTHOLOG OF APO1 (WAPO1). Using transgenic overexpression in both a low and a high SPS line, we provide a functional validation for the role of this gene in determining SPS also in hexaploid wheat. We show that the expression levels of this gene positively correlate with SPS in multiple MAGIC founder lines under field conditions as well as in transgenic lines grown in the greenhouse. This work highlights the potential use of WAPO1 in hexaploid wheat for further yield increases. The impact of WAPO1 and SPS on yield depends on other genetic and environmental factors, hence, will require a finely balanced expression level to avoid the development of detrimental pleiotropic phenotypes.


Assuntos
Pão , Triticum , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Fenótipo , Locos de Características Quantitativas , Triticum/genética
20.
J Air Waste Manag Assoc ; 61(5): 494-503, 2011 05.
Artigo em Inglês | MEDLINE | ID: mdl-21608489

RESUMO

Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck.


Assuntos
Exposição Ambiental/prevenção & controle , Gasolina , Veículos Automotores/normas , Emissões de Veículos , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Gasolina/análise , Gasolina/toxicidade , Humanos , Tamanho da Partícula , Material Particulado/análise , Material Particulado/toxicidade , Instituições Acadêmicas , Saúde da População Urbana/normas , Emissões de Veículos/prevenção & controle , Emissões de Veículos/toxicidade , Pesos e Medidas/instrumentação , Pesos e Medidas/normas
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa