ABSTRACT
The successive use of Roundup Ready crops may difficult the management of volunteer plants originated from seed losses during harvest. In soybean, volunteer corn plants can exhibit higher interference and cause reduce yield depending on their density. The aim of this study was to quantify the economic threshold level (ETL) in soybean as a function of the competition of volunteer corn and to evaluate the chemical control in different phenological stages of development. The ETL and chemical control experiments were conducted in the field, under completely randomized and randomized block designs with one and three replicates, respectively. The variables analyzed were yield and ETL as functions of the competition of different volunteer corn populations (control, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24 and 32 plants m-2) and the chemical control with acetyl coenzyme-A carboxylase (ACCase) inhibitor herbicides alone or mixed with glyphosate in different phenological stages of development (V2-V3, V4-V5 and V6-V8) that were evaluated at seven, 14 and 21 days after application (DAA). The results showed higher competitive potential of volunteer corn in which the presence of one plant m-2 reduces the soybean yield in 17%. The ETL ranged from 0.14 to 0.78 plants m-2 and the control of volunteer corn must be carried out in low populations. The use of ACCase inhibitors herbicides alone or mixed with glyphosate demonstrated greater than 85% control in the V2-V3 phenological stage independent of the period evaluated. The effectiveness of all herbicides decreased with application delay with a control level above 87%, in the V6- V8 phenological stage, obtained only for fluazifop and haloxyfop herbicides alone or in mixed with glyphosate at 14 and 21 days after application.
O uso sucessivo de culturas "Roundup Ready" pode dificultar o manejo de plantas voluntárias originadas de sementes perdidas durante a colheita. Na soja, plantas de milho voluntário podem apresentar elevada interferência e causar redução da produtividade dependendo da sua densidade. O objetivo do estudo foi quantificar o nível de dano econômico (NDE) na soja em função da competição de milho voluntário e avaliar o controle químico em diferentes estádios fenológicos de desenvolvimento. Os experimentos de NDE e controle químico foram conduzidos a campo, em delineamento inteiramente e blocos casualizados com uma e três repetições, respectivamente. As variáveis analisadas foram a produtividade e o NDE em função da competição das diferentes populações de milho voluntário (zero; um; dois; quatro; seis; oito; 10; 12; 16; 20; 24 e 32 plantas m-²) e o controle químico com herbicidas inibidores da enzima acetil CoA carboxilase (ACCase) isolados ou misturados com o glifosato em diferentes estádios fenológicos de desenvolvimento (V2-V3; V4-V5 e V6-V8) que foram avaliados aos sete, 14 e 21 dias após a aplicação (DAA). Os resultados demonstraram maior potencial competitivo do milho voluntário onde a presença de uma planta m-2 reduziu a produtividade da soja em 17%. O NDE variou de 0,14 a 0,78 plantas m-2 e o controle do milho voluntário deve ser realizado em populações baixas. O uso de herbicidas inibidores da ACCase isolados ou misturados com o glifosato proporcionaram controle superior 85% no estádio fenológico V2-V3 independente do período avaliado. A eficácia de todos os herbicidas decresceu com o atraso da aplicação com um nível de controle acima de 87%, no estádio fenológico V6-V8, obtido apenas para os herbicidas fluazifope e haloxifope isolado ou em mistura com o glifosato aos 14 e 21 dias após aplicação.
Subject(s)
Seeds , Glycine max , Zea mays , HerbicidesABSTRACT
PURPOSE: Fungi have been known to be important aeroallergens for hundreds of years. Most studies have focused on total fungal concentration; however, the concentration of specific allergenic fungi may be more important on an individual basis. METHODS: Ten fungal allergic patients and 2 non-fungal allergic patients were enrolled. The patients with a decrease in physician or patient global assessment by more than 50% of their personal best were considered to have an exacerbation of allergic symptoms and to be in the active stage. Those who maintained their physician and patient global assessment scores at their personal best for more than 3 months were considered to be in the inactive stage. The concentrations of dominant fungi in the patients' houses and outdoors were measured by direct and viable counts at active and inactive stages. RESULTS: The exacerbation of allergic symptoms was not correlated with total fungal spore concentration or the indoor/outdoor ratio (I/O). Specific fungi, such as Cladosporium oxysporum (C. oxyspurum), C. cladosporioides, and Aspergillus niger (A. niger), were found to be significantly higher concentrations in the active stage than in the inactive stage. Presumed allergenic spore concentration threshold levels were 100 CFU/m3 for C. oxysporum, and 10 CFU/m3 for A. niger, Penicillium brevicompactum and Penicillium oxalicum. CONCLUSIONS: The major factor causing exacerbation of allergic symptoms in established fungal allergic patients may be the spore concentration of specific allergenic fungi rather than the total fungal concentration. These results may be useful in making recommendations as regards environmental control for fungal allergic patients.
Subject(s)
Humans , Aspergillus niger , Cladosporium , Colony Count, Microbial , Family Characteristics , Fungi , Hypersensitivity , Niger , Penicillium , Spores , Spores, FungalABSTRACT
Objective To find out the difference in Multi-channel Cochlear mapping between SPrint speech processor and ESPrit speech processor (ESPrit 3G) for better guidance of the mapping.Methods Nine cases of total deafness patients (aged 2-54 years old) using SPrint changed to using ESPrit 3G after 6 to 24 months. The threshold (T-L) of electro-audiogram using different speech processor, comfortable level, sound field audiometry in various ESPrit 3G programs and questionnaire results were compared and analyzed statistically.Results Using various speech processor programs, four patients(The first group) felt satisfied with hearing effects. There was no difference comparing with SPrint. There was significantly different in T-L and C-L acquired from five patients(The second group) with two speech processors (P0.05). The results of sound field audiometry showed significant difference in the first group and the second group using programs from SPrint(P
ABSTRACT
BACKGROUND: This is to evaluate the noisy environment, and to improve the hearing conservation program by analyzing the status of hearing loss and risk factors which cause hearing loss of Airlines pilots. METHODS: We reviewed Audiometric, Medical and Flying records of total 92 pilots under 55 years old . These subjects selected after excluding pilots with history of ear disease and ototoxic drug administration. The significance of the factors was analyzed by ANOVA and Regression test. RESULT: The mean age of pilots was 39.96 years old and the mean flight time was 5665.39 hours. The noise levels by aircrafts were mean 76.9dB and maximum 144.4dB in B737, mean 78.5dB and maximum 143.2dB in B747. The noise levels by headset were mean 72.1dB and maximum 144.1dB. The mean hearing threshold level was different with age groups. The older in age, the higher in the mean hearing threshold level at high frequency and left ear. It was increased the mean hearing threshold level (dB) at high frequency (4,000 Hz) by total flight time The effect on hearing threshold level at high frequency in left ear was statistically significant in total flight time (p=0.032). CONCLUSION: The noise level of aircrafts could cause noise-induced hearing loss in some pilots. Age and total flight time are within the range of possibility of hearing loss. The result of this study ascertained the possibility of hearing loss due to monaural-headsets on the left ear at 4,000 Hz. It is recommended that an effective hearing conservation program should be provided for the headset-wearing communication pilots.
Subject(s)
Humans , Middle Aged , Aircraft , Diptera , Ear , Ear Diseases , Hearing Loss , Hearing Loss, Noise-Induced , Hearing , Noise , Risk FactorsABSTRACT
Objective: To determine the effects of different levels of zinc deficiency and zinc supplementation in the early stage of pregnancy on the development of the female mice and their fetus, and the lowest toxic level was also investigated. [WT5FZ]Methods: The model of zinc deficiency (ZD) was established on Kunmin mice and the experiment included two parts. Part one: 36 female mice (14～18 g) were randomly divided into 3 groups, zinc deficient group (ZD); middle zinc group (ZM); normal zinc group (ZN). They were fed for 50 days and mated with male mice. Part two: 80 female mice (25～30 g) were randomly divided into 4 groups, zinc deficient group (ZD); zinc suppplemented group (ZS); zinc marginally deficient group (MD); normal zinc group (ZN). They were fed 25 days for depleting the zinc store in body, then mated with male mice. All the pregnant mice were killed on the 18 th day of pregnancy. The content of zinc in diet for different levels groups were: (3.0?0.5) mg/kg (ZD), 9 mg/kg (MD group), 15 mg/kg (ZM), 30 mg/kg (ZN).The mice in group ZS were fed ZD diet at first and then were changed to ZN diet at the 7 th day of pregnancy. [WT5FZ]Results: Part one: 1. The zinc content in serum was lower in ZD group (P